阅读说明：本技术 摄像装置和电子设备 (Imaging device and electronic apparatus ) 是由 江尻洋一 于 2019-12-09 设计创作，主要内容包括：一种摄像装置,包括：第一基板,其包含将光转换成电荷的至少一个传感器部；和第二基板,其包含读出电路的第一部分,所述读出电路的第一部分具有至少一个第一晶体管。所述读出电路输出基于所述电荷的像素信号。所述摄像装置还包括：第三基板,其包含对所述像素信号进行处理的逻辑电路。所述第一基板、所述第二基板和所述第三基板按此顺序层叠着。(An image pickup apparatus comprising: a first substrate including at least one sensor portion that converts light into electric charges; and a second substrate including a first portion of a readout circuit having at least one first transistor. The readout circuit outputs a pixel signal based on the electric charges. The image pickup apparatus further includes: a third substrate including a logic circuit that processes the pixel signal. The first substrate, the second substrate, and the third substrate are stacked in this order.)

1. An image pickup apparatus comprising:

a first substrate including at least one sensor portion that converts light into electric charges;

a second substrate including a first portion of a readout circuit having at least one first transistor, the readout circuit outputting a pixel signal based on the charge; and

a third substrate including a logic circuit that processes the pixel signal,

wherein the first substrate, the second substrate, and the third substrate are stacked in this order.

2. The image pickup apparatus according to claim 1,

the first substrate further includes a floating diffusion portion that accumulates the charge, and

the at least one first transistor includes an amplification transistor whose gate electrode is connected to the floating diffusion.

3. The image pickup apparatus according to claim 1,

the at least one sensor part includes a plurality of sensor parts, and

the readout circuit includes analog-to-digital conversion circuits provided for the respective sensor sections.

4. The image pickup apparatus according to claim 1,

the readout circuit comprises a first part of an analog-to-digital conversion circuit, which contains a comparison circuit, and

the at least one first transistor is included in the comparison circuit.

5. The image pickup apparatus according to claim 1,

the at least one sensor portion comprises a plurality of sensor portions,

the plurality of sensor sections are arranged in rows and columns, and

the readout circuit includes analog-to-digital conversion circuits provided for the respective columns of the plurality of sensor units.

6. The image pickup apparatus according to claim 5,

the readout circuit includes a vertical signal line, and

the at least one first transistor includes a load transistor connected to the vertical signal line.

7. The image pickup apparatus according to claim 5,

the readout circuit includes a sample-and-hold circuit, and

the at least one first transistor includes: an input transistor included in the sample-and-hold circuit.

8. The image pickup apparatus according to claim 1, wherein the at least one first transistor includes:

a channel region disposed in the semiconductor region of the second substrate;

a gate insulating film provided on the channel region;

a gate electrode disposed on the gate insulating film;

a source region disposed in the semiconductor region of the second substrate at a position adjacent to the channel region;

a drain region provided in the semiconductor region of the second substrate at a position adjacent to the channel region on a side opposite to the source region;

a first metal layer disposed to cover a front surface of the gate electrode;

a second metal layer disposed to cover a front surface of the source region; and

a third metal layer disposed to cover a front surface of the drain region.

9. The image pickup apparatus according to claim 1,

the third substrate includes a second portion of the readout circuitry, the second portion of the readout circuitry is connected with the first portion of the readout circuitry, and the second portion of the readout circuitry includes a second transistor.

10. The image pickup apparatus according to claim 1,

the at least one first transistor comprises an NMOS transistor and/or a PMOS transistor, and

the at least one first transistor receives and outputs an analog signal based on the charge, and the second transistor receives and outputs a digital signal based on the analog signal.

11. The image pickup apparatus according to claim 9, wherein the at least one sensor section includes: a plurality of sensor sections sharing the at least one first transistor.

12. The image pickup apparatus according to claim 1, wherein the at least one sensor section includes a photodiode and a transfer transistor.

13. The image pickup apparatus according to claim 1, wherein the readout circuit includes at least one of an amplification transistor, a reset transistor, and a selection transistor.

14. The image pickup apparatus according to claim 1,

the first part of the readout circuit comprises a first part of an analog-to-digital conversion circuit and the logic circuit comprises a second part of the analog-to-digital conversion circuit, and

a first portion of the analog-to-digital conversion circuit receives an analog signal based on the charge and a second portion of the analog-to-digital conversion circuit outputs a digital signal based on the analog signal.

15. The image pickup apparatus according to claim 14, wherein the at least one sensor section includes a plurality of sensor sections that share a first portion of the analog-to-digital conversion circuit and a second portion of the analog-to-digital conversion circuit.

16. The image pickup apparatus according to claim 1,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes the plurality of sensor portions, and includes an isolation region separating the plurality of sensor portions.

17. The image pickup apparatus according to claim 1,

the at least one sensor portion comprises a plurality of sensor portions,

the first substrate includes the plurality of sensor portions, and

the readout circuit is electrically connected to the plurality of sensor units.

18. The image pickup apparatus according to claim 1,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes: and a floating diffusion portion provided for each of the plurality of sensor portions.

19. The image pickup apparatus according to claim 1,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes the plurality of sensor portions, and includes a floating diffusion portion shared by the plurality of sensor portions.

20. An electronic device, comprising:

an optical system;

a camera device; and

a signal processing circuit for processing the signal received from the signal receiving circuit,

the image pickup apparatus includes:

a first substrate including at least one sensor portion that converts light into electric charges;

a second substrate including a first portion of a readout circuit having at least one first transistor, the readout circuit outputting a pixel signal based on the charge; and

a third substrate including a logic circuit that processes the pixel signal,

wherein the first substrate, the second substrate, and the third substrate are stacked in this order.

Technical Field

The present invention relates to an image pickup apparatus and an electronic device using the same.

Background

One example of a circuit for reading signals from pixels in an image pickup apparatus is an analog-to-digital (a/D) converter including a comparator and a digital circuit arranged in a subsequent stage of the comparator (for example, see patent document 1). The A/D converter has high area efficiency.

Patent document 1 discloses an image pickup apparatus including a/D converters provided for respective pixels.

[ list of references ]

[ patent document ]

[ patent document 1] International publication No. WO 2016/136448

Disclosure of Invention

[ problem to be solved ]

In such an imaging apparatus, noise reduction is desired.

It is desirable to provide an image pickup apparatus and an electronic apparatus capable of reducing noise.

[ solution to problems ]

An image pickup apparatus according to an embodiment of the present invention includes a laminated structure including a first substrate, a second substrate, and a third substrate which are laminated in this order. The first substrate includes sensor pixels that perform photoelectric conversion and output signal charges. The second substrate includes a first signal processing circuit included in a readout circuit, the first signal processing circuit including a first analog transistor. The readout circuit outputs a pixel signal based on the signal charge. The third substrate includes a logic circuit that processes the pixel signal.

An image pickup apparatus according to an embodiment of the present invention includes: a first substrate including at least one sensor portion that converts light into electric charges; and a second substrate including a first portion of a readout circuit, the first portion of the readout circuit including at least one first transistor. The readout circuit outputs a pixel signal based on the electric charges. The image pickup apparatus further includes a third substrate including a logic circuit that processes the pixel signal. The first substrate, the second substrate, and the third substrate are stacked in this order. The first substrate further includes a floating diffusion that accumulates the charge, and the at least one first transistor includes an amplification transistor whose gate electrode is connected to the floating diffusion. The at least one sensor section includes a plurality of sensor sections, and the readout circuit includes analog-to-digital conversion circuits provided for each of the plurality of sensor sections, respectively. The readout circuit includes a first portion of the analog-to-digital conversion circuit that contains a comparison circuit, and the at least one first transistor is included in the comparison circuit. The at least one sensor section includes a plurality of sensor sections arranged in rows and columns, and the readout circuit includes analog-to-digital conversion circuits respectively provided for the respective columns of the plurality of sensor sections. The readout circuit includes a vertical signal line, and the at least one first transistor includes a load transistor connected to the vertical signal line. The readout circuit includes a sample-and-hold circuit, and the at least one first transistor includes an input transistor included in the sample-and-hold circuit. The at least one first transistor includes: a channel region disposed in the semiconductor region of the second substrate; a gate insulating film disposed on the channel region; a gate electrode disposed on the gate insulating film; a source region disposed in the semiconductor region of the second substrate at a position adjacent to the channel region; a drain region provided in the semiconductor region of the second substrate at a position adjacent to the channel region on a side opposite to the source region; a first metal layer disposed to cover a front surface of the gate electrode; a second metal layer disposed to cover a front surface of the source region; and a third metal layer disposed to cover a front surface of the drain region. The third substrate includes a second portion of the readout circuitry, the second portion of the readout circuitry is connected with the first portion of the readout circuitry, and the second portion of the readout circuitry includes a second transistor. The at least one first transistor includes an NMOS transistor and/or a PMOS transistor, and the at least one first transistor receives and outputs an analog signal based on the charge, and the second transistor receives and outputs a digital signal based on the analog signal. The at least one sensor portion includes: a plurality of sensor sections sharing the at least one first transistor. The at least one sensor section includes a photodiode and a transfer transistor. The readout circuit includes at least one of an amplification transistor, a reset transistor, and a selection transistor. The first portion of the readout circuitry comprises a first portion of analog-to-digital conversion circuitry and the logic circuitry comprises a second portion of the analog-to-digital conversion circuitry. A first portion of the analog-to-digital conversion circuit receives an analog signal based on the charge and a second portion of the analog-to-digital conversion circuit outputs a digital signal based on the analog signal. The at least one sensor section includes a plurality of sensor sections that share a first portion and a second portion of the analog-to-digital conversion circuit. The at least one sensor portion includes a plurality of sensor portions, and the first substrate includes the plurality of sensor portions, and the first substrate includes an isolation region separating the plurality of sensor portions. The at least one sensor portion includes a plurality of sensor portions, the first substrate includes the plurality of sensor portions, and the readout circuit is electrically connected to the plurality of sensor portions. The at least one sensor portion includes a plurality of sensor portions, and the first substrate includes floating diffusion portions provided for each of the plurality of sensor portions. The at least one sensor section includes a plurality of sensor sections, and the first substrate includes the plurality of sensor sections, and the first substrate includes a floating diffusion section common to the plurality of sensor sections.

An electronic device according to an embodiment of the present invention includes: an optical system, an image pickup apparatus, and a signal processing circuit. The imaging device includes a laminated structure including a first substrate, a second substrate, and a third substrate that are laminated in this order. The first substrate includes sensor pixels that perform photoelectric conversion and output signal charges. The second substrate includes a first signal processing circuit included in a readout circuit, the first signal processing circuit including a first analog transistor. The readout circuit outputs a pixel signal based on the signal charge. The third substrate includes a logic circuit that processes the pixel signal.

An electronic device according to an embodiment of the present invention includes: an optical system, an image pickup apparatus, and a signal processing circuit. The image pickup apparatus includes: a first substrate including at least one sensor portion that converts light into electric charges; and a second substrate including a first portion of a readout circuit having at least one first transistor. The readout circuit outputs a pixel signal based on the electric charges. The image pickup apparatus further includes: a third substrate including a logic circuit that processes the pixel signal. The first substrate, the second substrate, and the third substrate are stacked in this order.

In the image pickup device and the electronic apparatus according to the embodiments of the present invention, the first signal processing circuit including the first analog transistor is provided in the second substrate, and the first signal processing circuit is included in a readout circuit that reads a pixel signal from the sensor pixel.

Drawings

The accompanying drawings are included to provide a further understanding of the present technology, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain various principles of the present technology.

Fig. 1 shows an example of a schematic configuration of an image pickup apparatus according to an embodiment of the present invention.

Fig. 2 shows an example of a sensor pixel and a readout circuit of the image pickup apparatus in fig. 1.

Fig. 3A illustrates an example of a layout of the first substrate of the image pickup apparatus in fig. 1.

Fig. 3B illustrates an example of a layout of the second substrate of the image pickup apparatus in fig. 1.

Fig. 3C shows a superposition of fig. 3A and 3B.

Fig. 4 shows an example of a cross-sectional configuration in the vertical direction of the image pickup apparatus in fig. 1.

Fig. 5A illustrates an example of a manufacturing process of the image pickup device in fig. 1.

Fig. 5B shows an example of a manufacturing process subsequent to fig. 5A.

Fig. 5C shows an example of a manufacturing process subsequent to fig. 5B.

Fig. 5D shows an example of a manufacturing process subsequent to fig. 5C.

Fig. 5E shows an example of the manufacturing process after fig. 5D.

Fig. 5F shows an example of the manufacturing process after fig. 5E.

Fig. 5G shows an example of a manufacturing process subsequent to fig. 5F.

Fig. 5H shows an example of the manufacturing process after fig. 5G.

Fig. 5I shows an example of the manufacturing process after fig. 5H.

Fig. 6 shows an example of a cross-sectional configuration in the vertical direction of the image pickup apparatus according to modification a.

Fig. 7A shows an example of a manufacturing process of the image pickup device in fig. 6.

Fig. 7B shows an example of a manufacturing process subsequent to fig. 7A.

Fig. 7C shows an example of a manufacturing process subsequent to fig. 7B.

Fig. 8 shows an example of a sensor pixel and a readout circuit of the image pickup apparatus according to modification B.

Fig. 9 shows an example of a sensor pixel and a readout circuit of the image pickup apparatus according to modification C.

Fig. 10 shows an example of a sensor pixel and a readout circuit of the image pickup apparatus according to modification D.

Fig. 11A illustrates an example of a sensor pixel and a readout circuit of the image pickup apparatus according to modification E.

Fig. 11B illustrates an example of a signal processing circuit of the image pickup apparatus according to modification E.

Fig. 12 shows an example of a signal processing circuit of the image pickup apparatus according to modification F.

Fig. 13 shows an example of a signal processing circuit of the image pickup apparatus according to modification G.

Fig. 14 shows an example of a signal processing circuit of the image pickup apparatus according to modification H.

Fig. 15 shows an example of a signal processing circuit of the image pickup apparatus according to modification I.

Fig. 16 illustrates an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 17 illustrates an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 18 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 19 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 20 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 21 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification J.

Fig. 22 shows an example of a cross-sectional configuration in the vertical direction of the image pickup apparatus according to modification K.

Fig. 23 shows an example of a cross-sectional configuration in the vertical direction of the image pickup apparatus according to modification L.

Fig. 24 illustrates an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to the modification M.

Fig. 25 illustrates an example of a sectional configuration in the horizontal direction of the image pickup apparatus according to the modification M.

Fig. 26 illustrates an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification N.

Fig. 27 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification O.

Fig. 28 illustrates an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification P.

Fig. 29 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification Q.

Fig. 30 shows an example of a cross-sectional configuration in the horizontal direction of the image pickup apparatus according to modification R.

Fig. 31 shows an example of a circuit configuration of an image pickup apparatus according to a modification S.

Fig. 32 shows an example in which the image pickup apparatus according to modification T includes three substrates stacked.

Fig. 33 shows an example in which the logic circuit is provided separately in the substrate including the sensor pixel and the substrate including the readout circuit in the image pickup device according to the modification U.

Fig. 34 shows an example in which a logic circuit is provided in the third substrate in the image pickup apparatus according to modification V.

Fig. 35 is a block diagram showing an example of a schematic configuration of an electronic apparatus including the image pickup device according to any one of the foregoing embodiments and modifications thereof.

Fig. 36 illustrates an example of a schematic configuration of an image pickup system including the image pickup apparatus according to any one of the foregoing embodiments and modifications thereof.

Fig. 37 shows an example of an image capturing process in the image capturing system in fig. 36.

Fig. 38 is a block diagram showing an example of a schematic configuration of a vehicle control system.

Fig. 39 is a diagram for assisting in explaining an example of the installation positions of the vehicle exterior information detecting unit and the imaging unit.

Fig. 40 is a diagram showing an example of a schematic configuration of an endoscopic surgical system.

Fig. 41 is a block diagram showing an example of the functional configuration of a camera head and a Camera Control Unit (CCU).

Detailed Description

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. Note that the description will be given in the following order.

1. Embodiment (image pickup apparatus): FIGS. 1 to 5I

Example in which the first signal processing circuit is provided in the second substrate

2. Modification (image pickup device)

Modification A: examples in which the first transistor includes a silicide layer: FIGS. 6 to 7C

Modification example B: examples in which the first signal processing circuit includes NMOS and PMOS: FIG. 8

Modification example C: an example in which the first signal processing circuit is shared by four pixels: FIG. 9

Modification example D: an example in which the first signal processing circuit is shared by four pixels: FIG. 10 shows a schematic view of a

Modification example E: examples in which the first signal processing circuit includes a load transistor: FIG. 11A and FIG. 11B

Modification F: an example in which the signal processing circuit includes a PMOS input type differential input circuit: FIG. 12

Modification example G: examples in which the signal processing circuit comprises a SAR type ADC: FIG. 13

Modification example H: examples in which the signal processing circuitry comprises an ADC with a Δ Σ core (Δ Σ core): FIG. 14

Modification example I: examples in which the transistor of the first signal processing circuit includes a high-voltage drive transistor: FIG. 15 shows a schematic view of a

Modification J: an example in which the first signal processing circuit is shared by four pixels: FIGS. 16 to 21

Modification example K: an example in which a planar transfer gate electrode TG is used: FIG. 22

Modification L: examples where Cu-Cu bonding is used at the panel periphery: FIG. 23 shows a schematic view of a display panel

Modification example M: examples where an offset is provided between the sensor pixel and the readout circuitry: FIG. 24 and FIG. 25

Modification example N: an example in which a silicon substrate containing a first signal processing circuit has an island shape: FIG. 26

Modification example O: an example in which a silicon substrate containing a first signal processing circuit has an island shape: FIG. 27

Modification example P: an example where FD is shared by four sensor pixels: FIG. 28

Modification Q: an example where FD is shared by four sensor pixels: FIG. 29

Modification example R: an example where FD is shared by four sensor pixels: FIG. 30

Modification example S: wherein the column signal processing circuit includes an example of a general column ADC circuit: FIG. 31

Modification T: an example in which the image pickup apparatus includes three substrates stacked: FIG. 32

Modification example U: an example in which the logic circuit is provided in the first substrate and the second substrate: FIG. 33

Modification example V: an example in which the logic circuit is provided in the third substrate: FIG. 34

Modification W: examples of n-type and p-type switching of semiconductor regions

3. Application example

Application example 1: an example in which the image pickup apparatus according to any one of the foregoing embodiments and modifications thereof is applied to an electronic apparatus: FIG. 35 is a schematic view of a

Application example 2: an example in which the image pickup apparatus according to any one of the foregoing embodiments and modifications thereof is applied to an image pickup system: FIG. 36 and FIG. 37

4. Application example

Application example 1: an example in which the image pickup apparatus according to any one of the foregoing embodiments and modifications thereof is applied to a mobile body: FIG. 38 and FIG. 39

Application example 2: an example in which the image pickup apparatus according to any one of the foregoing embodiments and modifications thereof is applied to a surgical system: FIG. 40 and FIG. 41

(1. embodiment)

Example of construction

Fig. 1 shows an example of a schematic configuration of an image pickup apparatus 1 according to an embodiment of the present invention. The image pickup device 1 includes three substrates, i.e., a first substrate 10, a second substrate 20, and a third substrate 30. The image pickup apparatus 1 has a three-dimensional configuration in which three substrates (i.e., a first substrate 10, a second substrate 20, and a third substrate 30) are bonded together. The first substrate 10, the second substrate 20, and the third substrate 30 are stacked in this order.

The first substrate 10 includes a plurality of sensor pixels (or sensor sections) 12 that perform photoelectric conversion and output signal charges (or charges) on a semiconductor substrate 11. In the embodiment of the present invention, the first substrate 10 corresponds to a specific but non-limiting example of "first substrate". In an embodiment of the invention, the sensor pixel 12 corresponds to a specific but non-limiting example of a "sensor pixel". A plurality of sensor pixels 12 are arranged in rows and columns in a pixel region 13 of the first substrate 10.

The second substrate 20 includes a first signal processing circuit 22A on the semiconductor substrate 21. One first signal processing circuit 22A is provided for each sensor pixel 12. In the embodiment of the present invention, the second substrate 20 corresponds to a specific but non-limiting example of "second substrate". In the embodiment of the present invention, the first signal processing circuit 22A corresponds to a specific but non-limiting example of "a first signal processing circuit". The first signal processing circuit 22A is included in a readout circuit 22, and the readout circuit 22 outputs a pixel signal based on the signal charge output from the sensor pixel 12. The second substrate 20 includes a plurality of pixel driving lines 23 extending in a row direction. Further, a signal readout line 24A is provided in a subsequent stage of the readout circuit 22. The signal readout line 24A may be provided in any of the second substrate 20 and the third substrate 30.

The third substrate 30 includes the second signal processing circuit 22B and the logic circuit 32 on the semiconductor substrate 31. The logic circuit 32 processes the pixel signals. In the embodiment of the present invention, the third substrate 30 corresponds to a specific but non-limiting example of "third substrate". In an embodiment of the invention, the logic circuit 32 corresponds to a specific but non-limiting example of a "logic circuit". One second signal processing circuit 22B is provided for each sensor pixel 12. The first signal processing circuit 22A and the second signal processing circuit 22B are included in the readout circuit 22. One readout circuit 22 is provided for each sensor pixel 12. The logic circuit 32 includes, for example, a vertical drive circuit 33, a signal processing circuit 34, a horizontal drive circuit 35, and a system control circuit 36. The readout circuit 22 is connected to the signal processing circuit 34 via the signal readout line 24A. The signal processing circuit 34 is connected to the horizontal drive circuit 35. The logic circuit 32 (specifically, the horizontal drive circuit 35) outputs the output voltage Vout of each sensor pixel 12 to an external unit. In the image pickup apparatus 1, the second signal processing circuit 22B is provided in the third substrate 30. Further, in the image pickup apparatus 1, the signal processing circuit 34 is provided in the third substrate 30; however, all or a part of the signal processing circuit 34 may be provided in the second substrate 20. In addition, in the image pickup apparatus 1, the vertical driving circuit 33 is provided in the third substrate 30; however, the vertical driving circuit 33 may be disposed in the first substrate 10 and the second substrate 20.

In the image pickup apparatus 1, the readout circuit 22 includes an analog-to-digital conversion circuit (i.e., a/D converter). In the imaging apparatus 1, a/D converters are provided for the respective sensor pixels 12. The readout circuit 22 performs Correlated Double Sampling (CDS) processing on the pixel signals output from the respective sensor pixels 12. For example, the readout circuit 22 performs CDS processing to extract the signal level of the pixel signal, and holds pixel data (pixel signal) corresponding to the light reception amount (i.e., the signal charge amount) of each sensor pixel 12. For example, the horizontal drive circuit 35 sequentially outputs the pixel data held by the readout circuit 22 to an external unit. For example, the system control circuit 36 controls the driving of the respective blocks (i.e., the vertical drive circuit 33, the signal processing circuit 34, and the horizontal drive circuit 35) in the logic circuit 32.

In the image pickup apparatus 1, a circuit including a combination of the readout circuit 22 and the signal processing circuit 34 may include an a/D converter. Even in this case, a/D converters may be provided for the respective sensor pixels 12. The a/D converter includes a comparison circuit, a latch storage section, and the like. The comparison circuit comprises a differential input circuit, a voltage conversion circuit, a positive feedback circuit and the like. For example, the readout circuit 22 includes a differential input circuit included in an a/D converter, and the signal processing circuit 34 includes a portion other than the differential input circuit in the a/D converter. Alternatively, the readout circuit 22 may include a comparison circuit included in the a/D converter, and the signal processing circuit 34 may include a portion of the a/D converter other than the comparison circuit. For example, the signal processing circuit 34 performs signal processing on the signal from the readout circuit 22 and saves the obtained pixel data, and the horizontal drive circuit 35 sequentially outputs the pixel data saved by the signal processing circuit 34 to an external unit. The signal processing circuit 34 may be provided for each sensor pixel 12, or the signal processing circuit 34 may be provided for each column of the sensor pixels 12 in the pixel region 13. A part of the signal processing circuit 34 may be provided separately for each sensor pixel 12, and the remaining part of the signal processing circuit 34 may be provided separately for each column of the sensor pixels 12.

Further, in the image pickup apparatus 1, a readout circuit 22 is provided for each sensor pixel 12; however, it is possible to have the readout circuitry 22 shared by two or more (e.g., four) sensor pixels 12. In this case, the signal processing circuits 34 may be provided separately for the groups of sensor pixels 12 in which the readout circuits 22 are shared, or the signal processing circuits 34 may be provided separately for the respective columns of the groups of sensor pixels 12. A part of the signal processing circuit 34 may be provided separately for the group of sensor pixels 12, and the remaining part of the signal processing circuit 34 may be provided separately for each column of the group of sensor pixels 12.

Fig. 2 shows an example of a sensor pixel 12 and a readout circuit 22. In the present embodiment, one readout circuit 22 is provided for each sensor pixel 12. The readout circuit 22 includes a first signal processing circuit 22A and a second signal processing circuit 22B.

For example, each sensor pixel 12 includes a photodiode PD, a transfer transistor TX, and a floating diffusion FD. The transfer transistor TX is electrically connected to the photodiode PD. The floating diffusion FD temporarily holds the electric charge output from the photodiode PD via the transfer transistor TX. The photodiode PD performs photoelectric conversion to generate signal charges corresponding to a light receiving amount. The cathode of the photodiode PD is electrically connected to the source of the transfer transistor TX, and the anode of the photodiode PD is electrically connected to a reference potential line (e.g., ground). The drain of the transfer transistor TX is electrically connected to the floating diffusion FD, and the gate of the transfer transistor TX is electrically connected to the pixel driving line 23. For example, the transmission transistor TX includes an n-channel metal oxide semiconductor (NMOS) transistor. Each sensor pixel 12 is disposed in the first substrate 10.

The floating diffusion FD is electrically connected to an input terminal of a first signal processing circuit 22A included in the readout circuit 22. The first signal processing circuit 22A includes a first analog transistor. For example, the first analog transistor includes an amplifying transistor AMP, a reference signal input transistor (REF), and a current source transistor (Vb). In the embodiment of the present invention, the amplifying transistor AMP, the reference signal input transistor (REF), and the current source transistor (Vb) correspond to a specific but non-limiting example of "first analog transistor". Each of the amplifying transistor AMP, the reference signal input transistor (REF), and the current source transistor (Vb) includes an NMOS transistor. The first signal processing circuit 22A also includes a reset transistor RST. The reset transistor RST includes an NMOS transistor. The first signal processing circuit 22A is provided in the second substrate 20. Further, although not shown in fig. 2, an FD transfer transistor FDG may be provided.

In the image pickup apparatus 1 according to the present embodiment, the first signal processing circuit 22A is included in a part of the readout circuit 22. The first signal processing circuit 22A includes: an amplifying transistor AMP, a reference signal input transistor REF, and a current source transistor Vb included in the differential input circuit. For example, the differential input circuit is included in a part of a comparison circuit constituting an a/D converter. The first signal processing circuit 22A may further include other analog transistors. For example, the first signal processing circuit 22A may include a transistor such as a reset transistor RST, a selection transistor SEL (if the selection transistor SEL is provided), or an FD transfer transistor FDG (if the FD transfer transistor FDG is provided) connected to the floating diffusion FD. The amplifying transistor AMP has a higher noise reduction effect when the dedicated area is increased, compared to other transistors. Therefore, the first signal processing circuit 22A preferably includes an amplifying transistor AMP.

The readout circuit 22 further includes a second signal processing circuit 22B. The second signal processing circuit 22B includes a second analog transistor. For example, the second analog transistor includes a transistor PTR1 and a transistor PTR 2. Each of the transistor PTR1 and the transistor PTR2 includes a p-channel metal oxide semiconductor (PMOS) transistor. The second signal processing circuit 22B is provided in the third substrate 30.

The amplifying transistor AMP, the reference signal input transistor REF, the current source transistor Vb, the transistor PTR1, and the transistor PTR2 are included in the differential input circuit. The input terminal of the differential input circuit serves as the gate of the amplifying transistor AMP, and the output terminal of the differential input circuit serves as the drain of the amplifying transistor AMP. The amplification transistor AMP functions as both a transistor for outputting a voltage signal corresponding to the signal charge from the sensor pixel 12 and a part of a differential input circuit. The source of the reset transistor RST is electrically connected to the floating diffusion FD, and the drain of the reset transistor RST is electrically connected to the drain of the amplification transistor AMP.

The transfer transistor TX transfers the charge of the photodiode PD to the floating diffusion FD in a case where the transfer transistor TX is brought into an ON (ON) state. For example, as shown in fig. 4 to be described later, the gate of the transfer transistor TX (i.e., the transfer gate electrode TG) extends by a depth from the front surface of the semiconductor substrate 11 through the well layer 42 into the photodiode PD. The reset transistor RST resets the potential of the floating diffusion FD to a predetermined potential. When the reset transistor RST is turned on, the potential of the floating diffusion FD is reset to the potential of the power supply line VDD. A selection transistor SEL may be provided as necessary, and controls the output timing of the pixel signal from the readout circuit 22. The amplifying transistor AMP includes a source follower type amplifier. The amplification transistor AMP outputs a pixel signal of a voltage corresponding to the level of the charge generated by the photodiode PD and held by the floating diffusion FD. The pixel signal of this voltage (when the selection transistor SEL is turned on in the case where the selection transistor SEL is provided) is output from the differential input circuit including the amplification transistor AMP to a circuit in a subsequent stage of the differential input circuit.

For example, a voltage conversion circuit, a positive feedback circuit, and the like are provided in the subsequent stage of the differential input circuit. The differential input circuit, the voltage conversion circuit, the positive feedback circuit and other components are included in the comparison circuit. For example, a latch control circuit, a latch storage section, and the like are provided in the subsequent stage of the comparison circuit. The comparison circuit, latch storage, and other components are included in the a/D converter. In the imaging apparatus 1, one a/D converter is provided for each sensor pixel 12. In the image pickup apparatus 1, for example, a circuit in a part of the a/D converter located in a subsequent stage of the differential input circuit is included in the second signal processing circuit 22B or the signal processing circuit 34. For example, a circuit from the floating diffusion FD to the a/D converter may correspond to the readout circuit 22. Alternatively, a circuit from the floating diffusion FD to the a/D converter up to the differential input circuit may correspond to the readout circuit 22. Alternatively, a circuit appropriately selected from the circuits of the floating diffusion FD to the a/D converter may correspond to the readout circuit 22. For example, an NMOS transistor of the readout circuit 22 is provided as the first signal processing circuit 22A in the second substrate 20. Further, the PMOS transistor of the readout circuit 22 is provided in the third substrate 30 as the second signal processing circuit 22B.

The FD transfer transistor FDG is used to switch conversion efficiency. In general, a pixel signal is small when shooting in a dark place. When conversion from charge to voltage is performed based on Q ═ CV, an increase in the capacitance of the floating diffusion FD (i.e., FD capacitance C) causes a decrease in V obtained when the charge is converted to voltage by the amplifying transistor AMP. On the other hand, when shooting in a bright place, the pixel signal is large; therefore, unless the FD capacitance C is sufficiently large, the floating diffusion FD cannot receive the charge of the photodiode FD. Further, in order to prevent V from becoming excessively large when the charge is converted into a voltage by the amplifying transistor AMP, in other words, to make V small, the FD capacitance C must be increased. In view of this, in the case where the FD transfer transistor FDG is turned on, the entire FD capacitance C increases because the gate capacitance of the FD transfer transistor FDG increases. On the other hand, in the case where the FD transfer transistor FDG is turned off, the entire FD capacitance C is reduced. Then, by turning the FD transfer transistor FDG on and off in this way, the FD capacitance C is made variable, which enables switching of the conversion efficiency.

Fig. 3A illustrates an example of the layout of the first substrate 10 of the image pickup apparatus 1. A transfer transistor TX and power supply lines (PWL and VSS) are arranged in one sensor pixel 12. A photodiode PD is provided in a portion other than the transfer transistor TX and the power supply lines (PWL and VSS). Fig. 3B illustrates an example of the layout of the second substrate 20 of the image pickup apparatus 1. In one sensor pixel 12, an amplification transistor AMP, a reference signal input transistor REF, a current source transistor Vb, and a reset transistor RST are arranged. Fig. 3C is a superposition of the layout in fig. 3A and the layout in fig. 3B. As can be seen from fig. 3C, the current source transistor Vb is located near the transfer transistor TX and the power supply lines (PWL and VSS), and partially overlaps the transfer transistor TX and the power supply lines (PWL and VSS); therefore, it is difficult to arrange the current source transistor Vb and the transfer transistor TX as well as the power supply lines (PWL and VSS) on the same substrate. In the present embodiment, the transmission transistor TX and the power supply lines (PWL and VSS) are arranged in the first substrate 10, and the amplification transistor AMP, the reference signal input transistor REF, the current source transistor Vb, and the reset transistor RST are arranged in the second substrate 20, and the first substrate 10 and the second substrate 20 are laminated. Thus, one pixel can be configured.

Fig. 4 shows an example of a cross-sectional configuration in the vertical direction of the image pickup apparatus 1. Fig. 4 shows a cross-sectional configuration of the image pickup device 1 at a position opposing the sensor pixel 12. The image pickup device 1 includes a first substrate 10, a second substrate 20, and a third substrate 30 stacked in this order, and further includes a color filter 40 and a light receiving lens 50 on the back surface side (i.e., the light incident surface side) of the first substrate 10. For example, one color filter 40 and one light receiving lens 50 are provided for each sensor pixel 12. In other words, the imaging apparatus 1 is a backside illumination type imaging apparatus.

The first substrate 10 is configured by laminating an insulating layer 46 on a semiconductor substrate 11. The insulating layer 46 corresponds to a part of the interlayer insulating film 51. The insulating layer 46 is provided in a gap between the semiconductor substrate 11 and a semiconductor substrate 21 described later. The semiconductor substrate 11 includes a silicon substrate. The semiconductor substrate 11 includes a p-well layer 42 at a portion at the front surface and its vicinity, and the semiconductor substrate 11 includes a photodiode PD having a conductivity type different from that of the p-well layer 42 in a region other than the portion at the front surface and its vicinity (i.e., in a region deeper than the p-well layer 42). The p-well layer 42 includes a p-type semiconductor region. The photodiode PD includes a semiconductor region having a conductivity type (specifically, n-type) different from that of the p-well layer 42. The semiconductor substrate 11 further includes a floating diffusion FD in the p-well layer 42, the floating diffusion FD being a semiconductor region having a conductivity type (specifically, n-type) different from that of the p-well layer 42.

The first substrate 10 includes the following members provided for the respective sensor pixels 12: a photodiode PD, a transfer transistor TX including a transfer gate electrode TG, and a floating diffusion FD. The transfer gate electrode TG includes a vertical gate and a gate electrode of the FD transfer transistor FDG. A vertical gate extracts charges from the photodiode PD, and a gate electrode of the FD transfer transistor FDG is disposed on the front surface of the semiconductor substrate 11. In the first substrate 10, the transfer transistor TX and the floating diffusion FD are provided in a part of the front surface side (the side opposite to the light incident surface side, i.e., the side where the second substrate 20 is located) of the semiconductor substrate 11. The first substrate 10 includes an element separating portion 43 that separates each sensor pixel 12. The element isolation portion 43 is provided so as to extend in the normal direction of the semiconductor substrate 11 (the direction perpendicular to the surface of the semiconductor substrate 11). The element separating portion 43 is provided between two sensor pixels 12 adjacent to each other. The element separating section 43 electrically separates the sensor pixels 12 adjacent to each other. For example, the element isolation portion 43 includes silicon oxide. For example, the element isolation portion 43 penetrates the semiconductor substrate 11. The first substrate 10 further includes a p-well layer 44, and the p-well layer 44 is in contact with the side surface of the element separating portion 43 on the photodiode PD side. The p-well layer 44 includes a semiconductor region having a conductivity type (specifically, p-type) different from that of the photodiode PD. A p-well layer 44A is provided at the interface between the semiconductor substrate 11 and the insulating layer 46. The p-well layer 44A includes the following semiconductor regions: which has the same conductivity type (specifically, p-type) as that of the p-well layer 42 and has a higher concentration than that of the p-well layer 42.

For example, the first substrate 10 further includes a fixed charge film 45 in contact with the back surface of the semiconductor substrate 11. The fixed charge film 45 is negatively charged to suppress generation of a dark current caused by an interface level on the light receiving surface side of the semiconductor substrate 11. The fixed charge film 45 includes, for example, an insulating film having negative fixed charges. Non-limiting examples of the material of such an insulating film include hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, and tantalum oxide. A hole accumulation layer is formed on the interface on the light receiving surface side of the semiconductor substrate 11 by an electric field induced by the fixed charge film 45. The hole accumulation layer suppresses generation of electrons from the interface. The color filter 40 is provided on the rear surface side of the semiconductor substrate 11. The color filter 40 is disposed in contact with the fixed charge film 45, and is disposed at a position opposing the sensor pixel 12 via the fixed charge film 45, for example. For example, the light receiving lens 50 is disposed in contact with the color filter 40, and is disposed at a position opposing the sensor pixel 12 via the color filter 40 and the fixed charge film 45.

The second substrate 20 is configured by laminating an insulating layer 52 on the semiconductor substrate 21. The insulating layer 52 corresponds to a part of the interlayer insulating film 51. The insulating layer 52 is provided in the gap between the semiconductor substrate 21 and the semiconductor substrate 31. The semiconductor substrate 21 includes a silicon substrate. The second substrate 20 includes first signal processing circuits 22A provided for the respective sensor pixels 12. A portion of the second substrate 20 on the front surface side of the semiconductor substrate 21 (the side on which the third substrate 30 is located) includes therein a first signal processing circuit 22A. The second substrate 20 is bonded to the first substrate 10, and the back surface of the semiconductor substrate 21 faces the front surface side of the semiconductor substrate 11. In other words, the first substrate 10 and the second substrate 20 are attached to each other in a face-to-back (face-to-back) manner. The second substrate 20 further includes an insulating layer 53 in the same layer as the semiconductor substrate 21. The insulating layer 53 penetrates the semiconductor substrate 21. The insulating layer 53 corresponds to a part of the interlayer insulating film 51. The insulating layer 53 is provided so as to cover a side surface of a through wiring 54 described later.

For example, the first signal processing circuit 22A includes an amplifying transistor AMP, a reference signal input transistor REF, and a current source transistor Vb. Each of the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb includes an analog transistor. The amplification transistor AMP includes a p-type channel formation region (or channel region) of the semiconductor substrate 21, a gate electrode G1, and an n-type source/drain region SD 1. The gate electrode G1 is provided on the channel formation region with a gate insulating film interposed therebetween. The source/drain regions SD1 are provided in portions corresponding to both side portions of the gate electrode G1, respectively, within the semiconductor substrate 21, and sandwich the channel formation region between the two source/drain regions SD 1. The reference signal input transistor REF includes, like the amplification transistor AMP, a gate electrode G2 located on a p-type channel formation region of the semiconductor substrate 21 with a gate insulating film interposed therebetween, and includes n-type source/drain regions SD2 provided in portions corresponding to both side portions of the gate electrode G2, respectively, within the semiconductor substrate 21. The current source transistor Vb includes, like the amplification transistor AMP, a gate electrode G3 located on the p-type channel formation region of the semiconductor substrate 21 with a gate insulating film interposed therebetween, and includes n-type source/drain regions SD3 provided in portions corresponding to both side portions of the gate electrode G3, respectively, within the semiconductor substrate 21.

The laminate including the first substrate 10 and the second substrate 20 includes an interlayer insulating film 51 and a through wiring 54 provided in the interlayer insulating film 51. The laminate includes through-wirings 54 provided for the respective sensor pixels 12. The through wirings 54 each extend in the normal direction of the semiconductor substrate 21 and are provided so as to penetrate through the portion of the interlayer insulating film 51 including the insulating layer 53. The first substrate 10 and the second substrate 20 are electrically connected to each other via through-wiring 54. Specifically, the through wiring 54 is electrically connected to the floating diffusion FD and also electrically connected to a connection wiring 55 described later.

The laminated body including the first substrate 10 and the second substrate 20 further includes through wirings 47 and 48 provided in an interlayer insulating film 51 (see fig. 16 described later). The laminate includes through-wirings 47 provided for the respective sensor pixels 12, and includes through-wirings 48 provided for the respective sensor pixels 12. The through wirings 47 and 48 each extend in the normal direction of the semiconductor substrate 21 and are provided so as to penetrate through the portion of the interlayer insulating film 51 including the insulating layer 53. The first substrate 10 and the second substrate 20 are electrically connected to each other via through-wirings 47 and 48. Specifically, the through wiring 47 is electrically connected to the p-well layer 42 in the semiconductor substrate 11 and also electrically connected to the wiring in the second substrate 20. The through wiring 48 is electrically connected to the transfer gate electrode TG and also electrically connected to the pixel drive line 23.

For example, the second substrate 20 includes a plurality of connection portions 59 in the insulating layer 52. The plurality of connection portions 59 are electrically connected to the readout circuit 22 and the semiconductor substrate 21. For example, the second substrate 20 further includes a wiring layer 56 on the insulating layer 52. For example, the wiring layer 56 includes an insulating layer 57, a plurality of pixel drive lines 23, and a plurality of signal read-out lines 24A. The pixel driving line 23 and the signal readout line 24A are both provided in the insulating layer 57. The wiring layer 56 also includes a connection wiring 55. The connection wiring 55 electrically connects the through wirings 54 electrically connected to the floating diffusion FD included in the sensor pixel 12 to each other. Here, the total number of the through wirings 54 and 48 is larger than the total number of the sensor pixels 12 included in the first substrate 10, and twice the total number of the sensor pixels 12 included in the first substrate 10. Further, the total number of the through wirings 54, 48, and 47 is larger than the total number of the sensor pixels 12 included in the first substrate 10, and is three times the total number of the sensor pixels 12 included in the first substrate 10.

For example, the wiring layer 56 further includes a plurality of pad electrodes 58 in the insulating layer 57. Each pad electrode 58 includes a metal such as copper (Cu) or aluminum (Al), for example. Each pad electrode 58 is exposed from the front surface of the wiring layer 56. Each of the pad electrodes 58 is used for electrical connection between the second substrate 20 and the third substrate 30 and bonding between the second substrate 20 and the third substrate 30. For example, one pad electrode 58 is provided for each pixel driving line 23 and each signal readout line 24A, respectively. Here, the total number of the pad electrodes 58 or the total number of the bonding points between the pad electrodes 58 and the pad electrodes 64, which will be described later, is smaller than the total number of the sensor pixels 12 included in the first substrate 10.

For example, the third substrate 30 is configured by laminating an interlayer insulating film 61 on the semiconductor substrate 31. Note that the front surface of the third substrate 30 is attached to the front surface of the second substrate 20; therefore, in explaining the configuration of the third substrate, the top side and the bottom side are opposite to the top and bottom in the drawing. The semiconductor substrate 31 includes a silicon substrate. A portion of the third substrate 30 on the front surface side of the semiconductor substrate 31 includes the second signal processing circuit 22B and the logic circuit 32. For example, the third substrate 30 further includes a wiring layer 62 on the interlayer insulating film 61. For example, the wiring layer 62 includes an insulating layer 63 and a plurality of pad electrodes 64 provided in the insulating layer 63. The plurality of pad electrodes 64 are electrically connected to the second signal processing circuit 22B and the logic circuit 32. Each of the pad electrodes 64 includes, for example, copper (Cu). Each pad electrode 64 is exposed from the front surface of the wiring layer 62. Each of the pad electrodes 64 is used for electrical connection between the second substrate 20 and the third substrate 30 and bonding between the second substrate 20 and the third substrate 30. Further, the number of the pad electrodes 64 is not necessarily two or more, and even if the number of the pad electrodes 64 is one, the pad electrodes 64 may be electrically connected to the second signal processing circuit 22B or the logic circuit 32. The second substrate 20 and the third substrate 30 are electrically connected to each other by bonding between the pad electrodes 58 and 64. In other words, the gate of the transfer transistor TX (i.e., the transfer gate electrode TG) is electrically connected to the second signal processing circuit 22B or the logic circuit 32 via the through wiring 54 and the pad electrodes 58 and 64. The third substrate 30 is bonded to the second substrate 20, and the front surface of the semiconductor substrate 31 faces the front surface side of the semiconductor substrate 21. In other words, the third substrate 30 and the second substrate 20 are bonded in a face-to-face (face-to-face) manner.

For example, the second signal processing circuit 22B includes a transistor PTR1 and a transistor PTR 2. Each of the transistor PTR1 and the transistor PTR2 includes an analog transistor. Each of the transistor PTR1 and the transistor PTR2 includes a PMOS transistor. Fig. 4 shows one transistor as representative of the transistor PTR1 and the transistor PTR 2. The transistor included in the second signal processing circuit 22B includes a gate electrode G4 located on an n-type channel formation region of the semiconductor substrate 31 with a gate insulating film interposed therebetween, and includes p-type source/drain regions SD4 located in portions corresponding to both side portions of the gate electrode G4, respectively, within the semiconductor substrate 31.

For example, the logic circuit 32 includes Complementary Metal Oxide Semiconductor (CMOS) transistors. Fig. 4 shows one transistor as a representative of the transistors included in the logic circuit 32. The transistor included in the logic circuit 32 includes a gate electrode G5 located on a channel formation region of the semiconductor substrate 31 with a gate insulating film interposed therebetween, and includes source/drain regions SD5 located in portions corresponding to both side portions of the gate electrode G5, respectively, within the semiconductor substrate 31.

Manufacturing method

Next, a description will be given of a method of manufacturing the imaging device 1. Fig. 5A to 5I each show an example of a manufacturing process of the imaging device 1. Fig. 5A to 5I do not show a portion from halfway of the photodiode PD to the light receiving lens 50.

First, the p-well layer 42, the element isolation portion 43, and the p-well layer 44 are formed on the semiconductor substrate 11. Next, the photodiode PD and the transfer gate electrode TG of the transfer transistor TX are formed in the semiconductor substrate 11 (fig. 5A). Thus, the sensor pixels 12 are formed on the semiconductor substrate 11. In this case, as an electrode material for the sensor pixel 12, it is preferable that a self aligned silicide (CoSi) process such as that manufactured by a CoSi process is not used₂And NiSi and the like having low heat resistance. Instead, as an electrode material for the sensor pixel 12, it is preferable to use a material having high heat resistance. Non-limiting examples of the material having high heat resistance include polysilicon. The transfer gate electrode TG of the transfer transistor TX is formed by: for example, polysilicon containing phosphorus is formed by using a Chemical Vapor Deposition (CVD) methodA film having a thickness in the range of 50nm to 300nm, and performing a patterning process on the polycrystalline silicon by forming a pattern of a resist film using a photolithography process and a dry etching process. Alternatively, the transfer gate electrode TG of the transfer transistor TX is formed by: for example, by forming polysilicon containing no impurity into a film having a thickness in the range of 50nm to 300nm, by ion implantation to be 1 × 10¹⁵Ion/cm²To 1X 10¹⁶Ion/cm²Phosphorus is added in a range of dosage, and patterning is performed by a photolithography process and a dry etching process.

Subsequently, a floating diffusion FD and a p-well layer 44A are formed on the front surface of the semiconductor substrate 11 by ion implantation, and thereafter, an insulating layer (PMD: Pre-Metal-Dielectric layer) 46 is formed on the semiconductor substrate 11, and planarization is performed (fig. 5B). Thereby, the first substrate 10 is formed. The planarized insulating layer 46 preferably has a thickness in the range of about 200nm to about 2 μm.

Next, the semiconductor substrate 21 is bonded to the first substrate 10 (insulating layer 46) (fig. 5C). In this case, the semiconductor substrate 21 is thinned as necessary. At this time, the thickness of the semiconductor substrate 21 is reduced to a thickness necessary for forming the first signal processing circuit 22A. The thickness of the semiconductor substrate 21 is generally about several hundred nm. However, according to the concept of the first signal processing circuit 22A, the semiconductor substrate 21 can be completely depleted. In this case, the thickness of the semiconductor substrate 21 may be in the range of several nm to several μm.

Subsequently, an insulating layer 53 is formed in the same layer as the semiconductor substrate 21 (fig. 5D). For example, the insulating layer 53 is formed at a position opposing the floating diffusion FD. For example, slits penetrating the semiconductor substrate 21 are formed in the semiconductor substrate 21, thereby separating the semiconductor substrate 21 into a plurality of blocks 21A. Next, the insulating layer 53 is formed so as to be buried in the slit.

Subsequently, ion implantation is performed on each block 21A of the semiconductor substrate 21 to form a channel formation region. Then, the resultant is formed on a semiconductor substrate 21 by a thermal oxidation method, a CVD method or the likeA gate insulating film including silicon oxide is formed on the front surface of each block 21A. Subsequently, gate electrodes G1, G2, and G3 were formed. The gate electrodes G1, G2, and G3 are formed by: for example, the patterning process is performed on the polysilicon by forming the polysilicon containing phosphorus into a film having a thickness in the range of 50nm to 300nm by a CVD method, and forming a pattern of a resist film by a photolithography process and a dry etching process. Alternatively, the gate electrodes G1, G2, and G3 are formed by: for example, by forming polysilicon containing no impurity into a film having a thickness in the range of 50nm to 300nm, by ion implantation to be 1 × 10¹⁵Ion/cm²To 1X 10¹⁶Ion/cm²Phosphorus is added at a dose within the range, and patterning is performed by a photolithography process and a dry etching process. Next, source/drain regions SD1, SD2, and SD3 are formed by ion implantation. Thus, a first signal processing circuit 22A (fig. 5E) including the amplifying transistor AMP, the reference signal input transistor REF, the current source transistor Vb, and other components is formed. In the case where a metal material having high heat resistance is used as the electrode material of the sensor pixel 12, it is preferable that the gate insulating film be formed by a thermal oxidation method.

Subsequently, an insulating layer 52 is formed on the semiconductor substrate 21. Thus, the interlayer insulating film 51 including the insulating layers 46, 52, and 53 is formed. Next, heat treatment for impurity activation is performed. In this case, the impurity is diffused in the floating diffusion FD and the source/drain regions SD1, SD2, and SD 3. Subsequently, the front surface of the insulating layer 52 is planarized, and through holes 51A and 51B are formed in the interlayer insulating film 51 (fig. 5F). Specifically, the through-holes 51B penetrating the insulating layer 52 are formed at positions of the insulating layer 52 opposing the gate electrodes and the source/drain regions of the respective transistors of the first signal processing circuit 22A. Further, a through-hole 51A penetrating the interlayer insulating film 51 is formed at a position of the interlayer insulating film 51 opposing the floating diffusion FD (i.e., a position opposing the insulating layer 53).

Next, a conductive material is embedded in the through holes 51A and 51B, thereby forming the through wiring 54 in the through hole 51A and the connection portion 59 in the through hole 51B (fig. 5F). The embedding of the conductive material in the through holes 51A and 51B is performed by: for example, a titanium/titanium nitride film is formed on the inner wall surfaces of the respective through holes 51A and 51B by MO-CVD (metal organic CVD), tungsten is further formed into a film by CVD and buried in the through holes 51A and 51B, and the conductive material outside the through holes 51A and 51B is removed. Further, a connection wiring 55 (fig. 5F) for electrically connecting the through wiring 54 and the connection portion 59 to each other is formed on the insulating layer 52. Next, a wiring layer 56 is formed on the insulating layer 52, the wiring layer 56 including an insulating layer 57 and conductive layers such as the pixel drive line 23, the signal readout line 24A, and the pad electrode 58. The conductive layer is formed, for example, by a damascene method using copper. In the damascene method, for example, an insulating film for constituting the insulating layer 57 is formed; forming a trench having a conductive layer pattern in the insulating film; burying copper in the trench; and removing the copper outside the trench. Thus, the second substrate 20 is formed (fig. 5G).

On the other hand, the third substrate 30 in which the second signal processing circuit 22B, the logic circuit 32, and the wiring layer 62 are formed is separately formed (fig. 5H). Subsequently, the second substrate 20 is attached to the third substrate 30 so that the front surface of the semiconductor substrate 21 is opposed to the front surface side of the semiconductor substrate 31 (fig. 5I). The pad electrode 58 of the second substrate 20 includes copper, and the pad electrode 64 of the third substrate 30 also includes copper. The pad electrode 58 of the second substrate 20 and the pad electrode 64 of the third substrate 30 are bonded to each other by copper-copper bonding to electrically connect the second substrate 20 and the third substrate 30 to each other. Next, the color filter 40 and the light receiving lens 50 are formed on the back surface side of the first substrate 10. Thereby, the imaging device 1 is manufactured.

Operation of

In the image pickup device 1, light (e.g., light having a wavelength in the visible region) is incident to the photodiode PD from the back side of the first substrate 10, and then, paired holes and electrons are generated (subjected to photoelectric conversion) in the photodiode PD. The transfer transistor TX becomes on-state, which causes the signal charge accumulated in the photodiode PD to be transferred to the floating diffusion FD. The signal charge accumulated in the floating diffusion FD is converted into a voltage signal by the amplifying transistor AMP, and the voltage signal is a/D converted by an a/D converter included in the readout circuit 22 and then output from the horizontal drive circuit 35.

Operation and effect of the imaging apparatus 1

In the image pickup apparatus 1 according to the present embodiment, the sensor pixel 12 is arranged in the first substrate 10, and the first signal processing circuit 22A having the first analog transistor and included in the readout circuit 22 is arranged in the second substrate 20. The first analog transistor includes an amplifying transistor AMP. The sensor pixel 12 and the analog transistor such as an amplifying transistor included in the readout circuit are arranged in different substrates, which can enlarge a dedicated area of the analog transistor. Next, the operation and effect will be described using comparative examples.

Patent document 1 discloses an image pickup apparatus in which one a/D converter is provided for each pixel. Here, the imaging device is realized by a structure in which one semiconductor substrate includes: a readout circuit including a photodiode, an amplifying transistor, and the like; and a part of a comparison circuit included in the a/D converter. In such an image pickup apparatus, it is desirable to reduce noise of a readout circuit including an amplification transistor and other components and a comparison circuit included in an a/D converter. Such noise can be reduced by increasing the dedicated area of the analog transistor (particularly, amplification transistor) included in the comparison circuit or the like; however, increasing the dedicated area of the amplifying transistor makes it difficult to secure the dedicated area of the photodiode provided in the same substrate, and it is difficult to achieve miniaturization of pixels and an increase in the number of pixels.

In the image pickup apparatus 1 according to the present embodiment, the sensor pixels 12 are arranged in the first substrate 10, and analog transistors such as amplification transistors included in the readout circuit are arranged in the second substrate 20. This makes it possible to increase the dedicated area of an analog transistor such as an amplifying transistor without reducing the dedicated area of the photodiode. By increasing the dedicated area of the analog transistor (particularly, the amplifying transistor), noise can be reduced.

Further, in the image pickup apparatus 1 according to the present embodiment, the amplification transistor AMP connected to the floating diffusion FD also functions as a part of a differential input circuit of a comparison circuit included in the a/D converter. This makes it possible to reduce the number of transistors and to increase the dedicated area of the amplifying transistor, thereby reducing noise.

Further, in the image pickup apparatus 1 according to the present embodiment, one a/D converter is provided as a signal processing circuit for each sensor pixel. This makes it possible to read out digital pixel signals generated by a/D conversion from the respective pixels, thus making it possible to realize a higher frame rate and image pickup characteristics in which no temporal distortion occurs within a frame.

As explained above, in the image pickup apparatus 1 according to the present embodiment, the sensor pixels 12 are arranged in the first substrate 10, and the analog transistors are arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistors without reducing the dedicated area of the photodiodes and thus reduce noise.

(2. modification)

Hereinafter, a description is given of a modification of the image pickup apparatus 1 according to the foregoing embodiment. Note that in the following modifications, components common to those in the foregoing embodiments are denoted by the same reference numerals.

Modification A

In the foregoing embodiment, the silicide layer is not provided in the analog transistor included in the first signal processing circuit 22A; however, a silicide layer may be provided. The silicide layer is prepared by using self-aligned silicide (self aligned silicide) process such as cobalt silicide (CoSi)₂) And metal silicide (hereinafter, also referred to as "silicide") such as nickel silicide (NiSi).

Fig. 6 shows an example of a cross-sectional configuration in the vertical direction of an image pickup apparatus 1A as a modification a. The image pickup apparatus 1A is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In the imaging device 1A, CoSi₂Or NiSi or the like, are provided at the silicide layers G1A, G2A and G3A, respectivelyThe front surface of the gate electrode G1 of the amplifying transistor AMP, the front surface of the gate electrode G2 of the reference signal input transistor REF, and the front surface of the gate electrode G3 of the current source transistor Vb. The amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb are included in the first signal processing circuit 22A. In the imaging device 1A, source/drain regions SD1A, SD2A, and SD3A that have been silicided are provided instead of the source/drain regions SD1, SD2, and SD 3. The silicide layers G1A, G2A, and G3A and the source/drain regions SD1A, SD2A, and SD3A that have been silicided are formed by a salicide process. Sidewalls SW1, SW2, and SW3 are disposed at both side portions of the gate electrodes G1, G2, and G3, respectively. Sidewalls SW1, SW2 and SW3 serve as a silicide block that protects portions that are not silicided in a salicide process. The image pickup apparatus 1A has a configuration similar to that in the foregoing embodiment, except for the above configuration.

In the image pickup apparatus 1A, silicide layers G1A, G2A, and G3A are provided on the front surfaces of the gate electrodes G1, G2, and G3, respectively, and source/drain regions SD1A, SD2A, and SD3A that have been silicided are provided in place of the source/drain regions SD1, SD2, and SD 3. The silicide has a low resistance, which makes it possible to significantly reduce the parasitic resistance of the transistor, thereby reducing noise by increasing the mutual inductance (mutual inductance) gm.

In general, siliciding a transistor on a substrate provided with a sensor pixel causes an increase in leakage current such as dark current in a pixel portion, deterioration in image quality such as an increase in bright spots, or a decrease in yield. In the image pickup apparatus 1A, since the transistor provided on a substrate (the second substrate 20) different from the first substrate 10 provided with the sensor pixel 12 is silicided, it is made possible to reduce the resistance of the transistor without causing problems such as a decrease in yield due to dark current characteristics and an increase in bright spots. This can reduce parasitic resistance of the transistor, thereby improving processing speed and reducing noise.

A description will be given of a method of manufacturing the imaging device 1A shown in fig. 6. Fig. 7A to 7C show the manufacturing steps of the imaging device 1A. Fig. 7A to 7C do not show a portion from halfway of the photodiode PD to the light receiving lens 50.

First, similarly to the processes up to the process in fig. 5E of the foregoing embodiment, the processes up to the process of laminating the semiconductor substrate 21 on the first substrate 10 and forming the first signal processing circuit 22A including the amplifying transistor AMP, the reference signal input transistor REF, the current source transistor Vb, and the like are performed.

Next, for example, silicon oxide is formed by a CVD method to completely cover the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb, and is etched back to form the side walls SW1, SW2, and SW3 at both side portions of the gate electrodes G1, G2, and G3. Subsequently, in a state where the front surfaces of the gate electrodes G1, G2, and G3 and the source/drain regions SD1, SD2, and SD3 are exposed, a metal film including cobalt, nickel, or any other metal is formed on the entire surface by, for example, a sputtering method. The metal film is formed in contact with silicon on the front surfaces of the gate electrodes G1, G2, and G3 and the source/drain regions SD1, SD2, and SD 3. Next, a cap film is formed on the upper layer of the metal film, and heat treatment is performed. The portion in which the metal and silicon are in contact with each other is alloyed (metal silicided) to form silicide layers G1A, G2A, and G3A and source/drain regions SD1A, SD2A, and SD3A that have been silicided. In the silicidation process, only a part of the gate electrodes G1, G2, and G3 and the source/drain regions SD1, SD2, and SD3 may be silicidated, or all of the gate electrodes G1, G2, and G3 and the source/drain regions SD1, SD2, and SD3 may be silicidated. Subsequently, the cap film and the unreacted metal film are removed by a cleaning process, and silicide is left (fig. 7A).

Similar to the processing in the foregoing embodiment, the following processing may be performed. In other words, the insulating layer 52 is formed on the semiconductor substrate 21; forming through holes 51A and 51B; and the through wiring 54 and the connection portion 59 are formed. Next, the connection wiring 55 is formed (fig. 7B).

Next, the wiring layer 56 is formed by forming an insulating film and by forming a conductive layer by a damascene method (fig. 7C). Subsequently, the second substrate 20 is attached to the third substrate 30, and the color filter 40 and the light receiving lens 50 are formed on the back surface side of the first substrate 10. Thereby, the imaging device 1A is manufactured.

In the image pickup apparatus 1A, in addition to the effects of the foregoing embodiment, since the transistor provided in the second substrate 20 is silicided, the resistance of the transistor can be reduced and noise can be reduced.

Modification B

In the foregoing embodiment, the analog transistors included in the first signal processing circuit 22A include only NMOS transistors such as the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb; however, the analog transistor described above is not limited thereto, and may include a PMOS transistor.

Fig. 8 shows an example of a sensor pixel and a readout circuit of the image pickup apparatus 1B as a modification B. The image pickup apparatus 1B is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In the image pickup apparatus 1B, the first signal processing circuit 22A includes an amplifying transistor AMP, a reference signal input transistor REF, a current source transistor Vb, a transistor PTR1, and a transistor PTR 2. Each of the transistor PTR1 and the transistor PTR2 is a PMOS transistor. In the image pickup apparatus 1B, the second signal processing circuit 22B is not provided, and the readout circuit 22 includes only the first signal processing circuit 22A. The readout circuit 22 corresponds to a differential input circuit included in the a/D converter. The readout circuit 22 outputs the pixel signal to the signal readout line 24A or to the signal processing circuit 34 or the like in the subsequent stage of the signal readout line 24A.

In the image pickup apparatus 1B, not only NMOS transistors such as the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb, but also PMOS transistors such as the transistor PTR1 and the transistor PTR2 are arranged in the second substrate 20 as the first signal processing circuit 22A. A logic circuit 32, and a signal processing circuit 34 such as an a/D converter (except for a portion corresponding to the differential input circuit), and the like are arranged in the third substrate 30.

In the image pickup apparatus 1B, as in the foregoing embodiment, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise.

Modification example C

In the foregoing embodiment, one first signal processing circuit 22A is provided for each sensor pixel 12; however, it is possible to have one first signal processing circuit 22A shared by two or more (e.g., four) sensor pixels 12. Here, "common" indicates that the outputs of all the four sensor pixels 12 are input to the first signal processing circuit 22A which is common.

Fig. 9 shows an example of a sensor pixel and a readout circuit of an image pickup device 1C as a modification C. The image pickup apparatus 1C is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In fig. 9, the floating diffusion FD of the four sensor pixels 12-1, 12-2, 12-3, and 12-4 is connected to one amplification transistor AMP. The input of the amplifying transistor AMP is switched by a transfer transistor TX included in each of the sensor pixels 12-1, 12-2, 12-3, and 12-4. A mechanism of controlling the transfer timing and performing a/D conversion for each sensor pixel 12 is employed. In the imaging apparatus 1C, one a/D converter is shared by four sensor pixels 12.

In the image pickup device 1C, the sensor pixels 12 are arranged in the first substrate 10; NMOS transistors such as an amplifying transistor AMP, a reference signal input transistor REF, and a current source transistor Vb included in the first signal processing circuit 22A are arranged in the second substrate 20; and PMOS transistors such as the transistors PTR1 and PTR2 included in the second signal processing circuit 22B are arranged in the third substrate 30. A logic circuit 32, and a signal processing circuit 34 such as an a/D converter (except for a portion corresponding to the differential input circuit) and the like are also arranged in the third substrate 30.

In the image pickup device 1C, as in the foregoing embodiment, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise. The number of sensor pixels 12 sharing the a/D converter (first signal processing circuit 22A) is not particularly limited, and this may be selected in consideration of the speed of the a/D conversion.

Modification example D

The first signal processing circuit 22A may be shared by two or more (e.g., four) sensor pixels 12 in a different circuit configuration from the image pickup device 1C.

Fig. 10 shows an example of a sensor pixel and a readout circuit of an image pickup device 1D as a modification D. The image pickup apparatus 1D is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In fig. 10, the floating diffusion portions FD of the four sensor pixels 12-1, 12-2, 12-3, and 12-4 are connected to four amplifying transistors AMP1, AMP2, AMP3, and AMP4, respectively. Four amplifying transistors AMP1, AMP2, AMP3, and AMP4 are connected to the selection transistors SEL1, SEL1, SEL3, and SEL4, respectively. Signal charges are read out from the floating diffusion FD of the sensor pixel 12 selected by the selection transistors SEL1, SEL2, SEL3, and SEL4, and are converted into voltage signals. Thereafter, the voltage signal is output to the signal readout line 24A, or to the signal processing circuit 34 or the like in the subsequent stage of the signal readout line 24A.

In the image pickup device 1D, the sensor pixels 12 are arranged in the first substrate 10. NMOS transistors such as an amplifying transistor AMP, a reference signal input transistor REF, a current source transistor Vb, and selection transistors SEL1, SEL2, SEL3, and SEL4 included in the first signal processing circuit 22A are arranged in the second substrate 20. PMOS transistors such as the transistor PTR1 and the transistor PTR2 included in the second signal processing circuit 22B are arranged in the third substrate 30. A logic circuit 32, and a signal processing circuit 34 such as an a/D converter (except for a portion corresponding to the differential input circuit) and the like are also arranged in the third substrate 30.

In the image pickup device 1D, as in the foregoing embodiment, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor and reduce noise without reducing the dedicated area of the photodiode. The number of sensor pixels 12 sharing the a/D converter (first signal processing circuit 22A) is not particularly limited, and may be selected in consideration of the speed of the a/D conversion.

Modification example E

In the imaging apparatus 1, one a/D converter is provided for each sensor pixel 12; however, one a/D converter may be provided for each column of the sensor pixels 12 in the pixel region 13, respectively. An image pickup apparatus including a/D converters provided for the respective sensor pixels 12 is referred to as a "pixel ADC type image pickup apparatus". An image pickup apparatus including a/D converters provided for respective columns of the sensor pixels 12 is referred to as a "column ADC type image pickup apparatus". In the column ADC type image pickup apparatus, the first signal processing circuit 22A may include: an amplification transistor AMP connected to the floating diffusion FD; and a load transistor of the vertical signal line 24.

Fig. 11A illustrates an example of the sensor pixel 12 and the first signal processing circuit 22A included in the readout circuit 22 of the imaging device 1E as a modification E. As shown in fig. 11A, the sensor pixel 12 includes a photodiode PD, a transfer transistor TX, and a floating diffusion FD. The sensor pixels 12 are arranged in the first substrate 10. The amplification transistor AMP, the reset transistor RST, and the selection transistor SEL are connected to the floating diffusion FD, the signal charge of the floating diffusion FD is converted into a voltage signal, and the voltage signal is output to the vertical signal line 24. A load transistor is provided for the vertical signal line 24. These amplifying transistor AMP, reset transistor RST, selection transistor SEL and load transistor are included in the first signal processing circuit 22A and are arranged in the second substrate 20.

Fig. 11B shows an example of the signal processing circuit 34 connected to a subsequent stage of the vertical signal line 24. The signal processing circuit 34 includes an a/D converter. The A/D converter includes a differential input circuit. Fig. 11B corresponds to a differential input circuit. A circuit 34E including an NMOS transistor surrounded by a dotted line in fig. 11B is arranged in the second substrate 20 as in the first signal processing circuit 22A. A logic circuit 32, analog transistors included in a signal processing circuit 34 such as an a/D converter (except for the circuit 34E), a memory section, and the like are arranged in the third substrate 30.

In the image pickup device 1E, as in the foregoing embodiment, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise.

With the image pickup apparatus having the circuit configuration shown in fig. 11A and 11B and in which the gate width of the amplifying transistor AMP is not increased (i.e., having one gate width of the amplifying transistor AMP), and with the image pickup apparatus having the circuit configuration shown in fig. 11A and 11B and in which the gate width of the amplifying transistor AMP is increased (i.e., having 1.5 gate widths of the amplifying transistor AMP), the noise reduction effect achieved by increasing the gate width is found by simulation. In the image pickup apparatus in which the gate width of the amplification transistor AMP is not increased, Random Noise (RN) after CDS processing is 51.6 μ Vrsm, and in the case where the gate width of the amplification transistor AMP is increased by 1.5 times, RN is 48.1 μ Vrms. Can reduce RN after CDS treatment by 6.8%. As conditions for the simulation, the cutoff frequency of the circuit after the amplification transistor AMP was 2.0MHz, and the CDS period was 1.9 μ S.

Modification F

The imaging device 1F as the modification F is a column ADC type imaging device. In the above-described image pickup apparatus 1E, the differential input circuit includes NMOS transistors to function as input units. However, a PMOS transistor may be used as the input unit.

In the image pickup device 1F, the sensor pixels 12 are arranged in the first substrate 10 as in the image pickup device 1E. The image pickup apparatus 1F includes a first signal processing circuit 22A similar to the first signal processing circuit 22A in fig. 11A. The amplifying transistor AMP, the reset transistor RST, the selection transistor SEL, and the load transistor included in the first signal processing circuit 22A are arranged in the second substrate 20.

Fig. 12 shows an example of the signal processing circuit 34 connected to a subsequent stage of the vertical signal line 24. The signal processing circuit 34 includes an a/D converter. The A/D converter includes a differential input circuit. The differential input circuit of the image pickup device 1F is of a PMOS transistor input type. A circuit 34F including NMOS transistors and PMOS transistors surrounded by a dotted line in fig. 12 is arranged in the second substrate 20 as the first signal processing circuit 22A. A logic circuit 32, analog transistors included in a signal processing circuit 34 such as an a/D converter (except for the circuit 34F), a memory section, and the like are arranged in the third substrate 30.

In the image pickup apparatus 1F, as in the foregoing embodiments, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise. Further, by disposing the analog transistor in the second substrate 20, it is allowed to have a configuration in which the analog transistor is not provided in the third substrate 30. In general, analog transistors require finer characteristic adjustment than logic transistors. Non-limiting examples of these finer characteristic adjustments include setting the threshold voltage to a lower voltage than the threshold voltage of the transistors of the logic circuit. The configuration without providing the analog transistor in the third substrate 30 can allow the third substrate 30 to be manufactured at low cost in a short process.

Modification G

The imaging device 1G as the modification G is a column ADC type imaging device. The a/D converters provided for the respective columns may be of a Successive Approximation Register (SAR) type.

In the image pickup device 1G, the sensor pixels 12 are arranged in the first substrate 10 as in the image pickup device 1E. The image pickup apparatus 1G includes a first signal processing circuit 22A similar to the first signal processing circuit 22A in fig. 11A. The amplifying transistor AMP, the reset transistor RST, the selection transistor SEL, and the load transistor included in the first signal processing circuit 22A are arranged in the second substrate 20.

Fig. 13 shows an example of the signal processing circuit 34 connected to a subsequent stage of the vertical signal line 24. The signal processing circuit 34 includes a SAR-type a/D converter. The A/D converter includes a differential input circuit. The differential input circuit of the image pickup device 1G is of a PMOS input type. A voltage digital-to-analog converter (VDAC) is connected to the reference signal input transistor. A circuit 34G including NMOS transistors and PMOS transistors surrounded by a dotted line in fig. 13 is arranged in the second substrate 20 as the first signal processing circuit 22A. In the imaging device 1G, the circuit 34G corresponds to a PMOS input type differential input circuit. A current sensing input unit of the sample-and-hold circuit and a Low Dropout (LDO) circuit are also arranged in the second substrate 20. Therefore, in addition to the amplifying transistor being arranged in the second substrate 20, the analog transistor that is possessed in a part of the differential input circuit included in the a/D converter is also arranged in the second substrate 20. A logic circuit 32, a digital-to-analog converter (DAC), an analog transistor (except for a current sensing input unit of a sample-and-hold circuit, an LDO circuit, and the like) included in the signal processing circuit 34 such as an a/D converter (except for the circuit 34G), and a memory section and the like are arranged in the third substrate 30.

In the image pickup device 1G, as in the foregoing embodiments, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise. Further, by disposing the analog transistor in the second substrate 20, it is allowed to have a configuration in which the analog transistor is not provided in the third substrate 30. This allows the third substrate 30 to be manufactured in a short process at low cost.

Modification example H

The imaging device 1H as the modification H is a column ADC type imaging device. The a/D converters provided for the respective columns may be a/D converters including delta-sigma kernels. In a/D converters containing a Δ Σ kernel, for example, the current is modulated into column current sources for column readout of the pixels at the feedback destination of the integrator and quantizer. The delta-sigma modulator may be built into the column, which makes it possible to achieve higher processing speeds.

In the image pickup device 1H, the sensor pixels 12 are arranged in the first substrate 10 as in the image pickup device 1E. The image pickup apparatus 1H includes a first signal processing circuit 22A similar to the first signal processing circuit 22A of fig. 11A. The amplifying transistor AMP, the reset transistor RST, the selection transistor SEL, and the load transistor included in the first signal processing circuit 22A are arranged in the second substrate 20.

Fig. 14 shows an example of the signal processing circuit 34 connected to a subsequent stage of the vertical signal line 24. The signal processing circuitry 34 includes an a/D converter including a delta-sigma core. The a/D converter includes a Δ Σ core, and in a preceding stage of the Δ Σ core, an input current control section 34H is included, and the input current control section 34H includes a sample-and-hold circuit S & H, LDO circuit and a voltage-to-current (V2I) circuit. The input current control section 34H is disposed in the second substrate 20 as in the first signal processing circuit 22A. Therefore, in addition to the amplifying transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20. A logic circuit 32, a DAC, analog transistors (except for the input current control section 34H) included in the signal processing circuit 34, a memory section, and the like are arranged in the third substrate 30.

In the image pickup apparatus 1H, as in the foregoing embodiments, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise. Further, by disposing the analog transistor in the second substrate 20, it is allowed to have a configuration in which the analog transistor is not provided in the third substrate 30. This enables the third substrate 30 to be manufactured in a short process at low cost.

Modification example I

The imaging device 1I as the modification I is a column ADC type imaging device. In the above-described image pickup devices 1E to 1H, the high-voltage drive transistors and the low-voltage drive transistors of the analog transistors are mixedly arranged in the second substrate 20 and the third substrate 30; however, the high voltage driving transistor and the low voltage driving transistor may be separately disposed in the second substrate 20 and the third substrate 30.

In the image pickup apparatus 1I, the sensor pixels 12 are arranged in the first substrate 10 as in the image pickup apparatus 1E. The image pickup apparatus 1I includes a first signal processing circuit 22A similar to the first signal processing circuit 22A in fig. 11A. The amplifying transistor AMP, the reset transistor RST, the selection transistor SEL, and the load transistor included in the first signal processing circuit 22A are arranged in the second substrate 20.

Fig. 15 shows an example of the signal processing circuit 34 connected to a subsequent stage of the vertical signal line 24. The signal processing circuit 34 includes an a/D converter. The A/D converter includes a differential input circuit. The differential input circuit of the imaging device 1I is of an NMOS input type. A RAMP (RAMP) waveform is input to the reference signal input transistor. A circuit 34I including NMOS transistors and PMOS transistors surrounded by a dotted line in fig. 15 is arranged in the second substrate 20 as the first signal processing circuit 22A. Therefore, in addition to the amplifying transistor being arranged in the second substrate 20, the analog transistor that is possessed in a part of the differential input circuit included in the a/D converter is also arranged in the second substrate 20. In the imaging device 1I, the circuit 34I corresponds to a differential input circuit. Other high voltage driving transistors are also disposed in the second substrate 20. On the other hand, a circuit including only low-voltage driving transistors, such as the logic circuit 32, and a memory portion are arranged in the third substrate 30.

In the image pickup apparatus 1I, as in the foregoing embodiment, the analog transistor is arranged in the second substrate 20, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise. Further, it is not necessary to dispose a high-voltage driving transistor in the third substrate, which can realize a shorter process and lower cost.

Modification J

The imaging device 1J as the modification J is a column ADC type imaging device. Fig. 16 and 17 respectively show examples of a sectional configuration in the horizontal direction of the image pickup apparatus 1J. The imaging device 1J is a modification of the structure in which one first signal processing circuit is shared by four pixels in any of the imaging devices 1E to 1I. The upper side view of each of fig. 16 and 17 shows an example of a cross section corresponding to the cross-sectional configuration taken along the section Sec1 in fig. 4, and the lower side view of each of fig. 16 and 17 shows an example of a cross section corresponding to the cross-sectional configuration taken along the section Sec2 in fig. 4. Fig. 16 illustrates a configuration in which 2 × 2 (i.e., four) sensor pixels 12 are arranged side by side in two sets along the second direction H, and fig. 17 illustrates a configuration in which 2 × 2 (i.e., four) sensor pixels 12 are arranged side by side in four sets along the first direction V and the second direction H. Note that, in the upper side sectional views of fig. 16 and 17, a view showing an example of the surface configuration of the semiconductor substrate 11 is superimposed on a view showing an example of the sectional configuration taken along the section Sec1 of fig. 4, and the insulating layer 46 is not shown. Further, in the lower side sectional views of fig. 16 and 17, a diagram showing an example of the surface configuration of the semiconductor substrate 21 is superimposed on a diagram showing an example of the sectional configuration taken along the section Sec2 in fig. 4. Note that, in the image pickup apparatus 1J, the first signal processing circuit 22A includes the amplifying transistor AMP, the reset transistor RST, and the selection transistor SEL. In the image pickup device 1J, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. As for the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

As shown in fig. 16, the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 are arranged side by side in a band shape along the first direction V (the up-down direction in fig. 16) in the plane of the first substrate 10. Note that fig. 16 illustrates a case where the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 are arranged side by side in two rows along the first direction V. Further, as shown in fig. 17, the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 are arranged side by side in a band shape along the second direction H (the left-right direction in fig. 17) in the plane of the first substrate 10. Note that fig. 17 illustrates an example in which the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 are arranged side by side in two columns along the second direction H. The first direction V is parallel to an arrangement direction (for example, a column direction) of one of two arrangement directions (for example, a row direction and a column direction) of the plurality of sensor pixels 12 arranged in a matrix. For example, in four sensor pixels 12 sharing the first signal processing circuit 22A, four floating diffusion portions FD are arranged close to each other with the element separating portion 43 interposed therebetween. For example, in four sensor pixels 12 that share the first signal processing circuit 22A, four transfer gate electrodes TG are arranged so as to surround four floating diffusion portions FD, and the four transfer gate electrodes TG form a ring shape.

The insulating layer 53 includes a plurality of blocks extending along the first direction V. The semiconductor substrate 21 includes a plurality of island-shaped blocks 21A extending along a first direction V, and the plurality of island-shaped blocks 21A are arranged side by side along a second direction H orthogonal to the first direction V via an insulating layer 53. For example, each block 21A includes a plurality of sets of reset transistors RST, amplification transistors AMP, and selection transistors SEL. For example, one first signal processing circuit 22A shared by four sensor pixels 12 includes a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL arranged in a region opposite to the four sensor pixels 12. For example, one readout circuit 22 shared by four sensor pixels 12 includes an amplification transistor in the block 21A located on the left side of the insulating layer 53, and a reset transistor RST and a selection transistor SEL in the block 21A located on the right side of the insulating layer 53.

Fig. 18, 19, 20, and 21 each show an example of a wiring layout of the imaging device 1J in a horizontal plane as a modification J. Fig. 18 to 21 respectively show examples in which one first signal processing circuit 22A shared by four sensor pixels 12 is provided in an area opposed to the four sensor pixels 12. For example, the wirings shown in fig. 18 to 21 are provided in different layers from each other in the wiring layer 56.

For example, as shown in fig. 18, four through wirings 54 adjacent to each other are electrically connected to the connection wiring 55. For example, as shown in fig. 18, four through wirings 54 adjacent to each other are further electrically connected to the gate of the amplifying transistor AMP included in the block 21A located on the left side of the insulating layer 53 and the gate of the reset transistor RST included in the block 21A located on the right side of the insulating layer 53 via the connection wiring 55 and the connection portion 59.

For example, as shown in fig. 19, the power supply line VDD is arranged at a position opposite to the respective first signal processing circuits 22A arranged side by side in the second direction H. For example, as shown in fig. 19, the power supply line VDD is electrically connected to the drain of the amplifying transistor AMP and the drain of the reset transistor RST in the respective first signal processing circuits 22A arranged side by side in the second direction H via the connection portion 59. For example, as shown in fig. 19, two pixel driving lines 23 are arranged at positions opposing the respective readout circuits 22 arranged side by side along the second direction H. As shown in fig. 19, one of the two pixel drive lines 23 (second control line) is, for example, a wiring RSTG electrically connected to the gates of the reset transistors RST of the respective readout circuits 22 arranged side by side along the second direction H. As shown in fig. 19, the other one (third control line) of the two pixel drive lines 23 is, for example, a wiring SELG electrically connected to the gates of the selection transistors SEL of the respective readout circuits 22 arranged side by side along the second direction H. For example, as shown in fig. 19, in each of the first signal processing circuits 22A, the source of the amplifying transistor AMP and the drain of the selection transistor SEL are electrically connected to each other via a wiring 25.

For example, as shown in fig. 20, two power supply lines VSS are arranged at positions opposite to the respective first signal processing circuits 22A arranged side by side in the second direction H. Each power supply line VSS is electrically connected to a plurality of through wirings 47, for example, at positions opposite to the respective sensor pixels 12 arranged side by side along the second direction H. For example, as shown in fig. 20, four pixel driving lines 23 are arranged at positions opposing the respective first signal processing circuits 22A arranged side by side along the second direction H. As shown in fig. 20, each of the four pixel drive lines 23 is, for example, a wiring TRG as follows: which is electrically connected to the through wiring 48 of one sensor pixel 12 of the four sensor pixels 12 corresponding to the respective first signal processing circuits 22A arranged side by side in the second direction H. In other words, four pixel driving lines 23 (first control lines) are electrically connected to the gates (transfer gate electrodes TG) of the transfer transistors TX of the respective sensor pixels 12 arranged side by side along the second direction H. In fig. 20, in order to distinguish the respective wirings TRG, identifiers (1, 2, 3, and 4) are given at the end of the respective wirings TRG.

For example, as shown in fig. 21, the vertical signal lines 24 are arranged at positions opposing the respective first signal processing circuits 22A arranged side by side along the first direction V. For example, as shown in fig. 21, the vertical signal lines 24 (output lines) are electrically connected to the output terminals (sources of the amplifying transistors AMP) of the respective readout circuits 22 arranged side by side along the first direction V.

Modification example K

Fig. 22 shows an example of a cross-sectional configuration in the vertical direction of an image pickup apparatus 1K as a modification K. The image pickup apparatus 1K is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In the imaging device 1K, the transfer transistor TX includes a planar transfer gate electrode TG. Therefore, the transfer gate electrode TG does not penetrate the well layer 42, and is provided only on the front surface of the semiconductor substrate 11. Even in the case where the transfer transistor TX uses the planar transfer gate electrode TG, the image pickup device 1K has effects similar to those of the foregoing embodiments. Note that in fig. 22, as the first signal processing circuit 22A, one transistor is shown as a representative of the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb. In the image pickup device 1K, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

Modification L

Fig. 23 shows an example of a cross-sectional configuration in the vertical direction of an image pickup apparatus 1L as a modification L. The image pickup apparatus 1L is a modification of the image pickup apparatus 1 according to the foregoing embodiment. In the imaging device 1L, the electrical connection between the second substrate 20 and the third substrate 30 is performed in a region opposed to the peripheral region 14 of the first substrate 10. The peripheral region 14 corresponds to a frame region of the first substrate 10, and is disposed at an outer edge of the pixel region 13. In the image pickup apparatus 1L, the second substrate 20 includes a plurality of pad electrodes 58 in a region opposite to the peripheral region 14, and the third substrate 30 includes a plurality of pad electrodes 64 in a region opposite to the peripheral region 14. The second substrate 20 and the third substrate 30 are electrically connected to each other by bonding between the pad electrode 58 provided in the region opposite to the peripheral region 14 and the pad electrode 64 provided in the region opposite to the peripheral region 14. Note that in fig. 23, as the first signal processing circuit 22A, one transistor is shown as a representative of the amplifying transistor AMP, the reference signal input transistor REF, and the current source transistor Vb. In the image pickup device 1L, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

As described above, in the image pickup apparatus 1L, the second substrate 20 and the third substrate 30 are electrically connected to each other by the bonding between the pad electrode 58 provided in the region opposed to the peripheral region 14 and the pad electrode 64 provided in the region opposed to the peripheral region 14. This can reduce the hindrance to the area miniaturization of each pixel that may occur, as compared with the case where the pad electrode 58 and the pad electrode 64 are bonded together in the region opposite to the pixel region 13. Therefore, the image pickup apparatus 1L having the three-layer configuration can be provided as follows: which has a chip size substantially equivalent to that before without hindering area miniaturization of each pixel.

Modification example M

The imaging device 1M as the modification M is a column ADC type imaging device. Fig. 24 and 25 respectively show examples of the sectional configuration in the horizontal direction of the image pickup apparatus 1M. The imaging device 1M is a modification of the structure in which one first signal processing circuit is shared by four pixels in any of the imaging devices 1E to 1I. The upper side view of each of fig. 24 and 25 shows a modification of the cross section corresponding to the cross-sectional configuration taken along the cross section Sec1 in fig. 4, and the lower side view of each of fig. 24 and 25 shows a modification of the cross section corresponding to the cross-sectional configuration taken along the cross section Sec2 in fig. 4. Note that, in the upper side cross-sectional views of fig. 24 and 25, a diagram showing a modification of the surface structure of the semiconductor substrate 11 is superimposed on a diagram showing a modification of the cross-sectional structure taken along the section Sec1 in fig. 4, and the insulating layer 46 is not shown. In the lower cross-sectional views of fig. 24 and 25, a modified example of the surface structure of the semiconductor substrate 21 is superimposed on a modified example of the cross-sectional structure taken along the section Sec2 of fig. 4. Note that in the example of fig. 24, for example, the first signal processing circuit 22A includes an amplifying transistor AMP, a reset transistor RST and a selection transistor SEL. Further, in the example of fig. 25, for example, the first signal processing circuit 22A includes an amplifying transistor AMP, a reset transistor RST, a selection transistor SEL, and an FD transmission transistor FDG. In the image pickup device 1M, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

As shown in fig. 24 and 25, the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 (a plurality of dots arranged in rows and columns in the drawing) are arranged side by side in a stripe shape along the second direction H (the left-right direction in fig. 24 and 25) in the plane of the first substrate 10. Note that fig. 24 and 25 illustrate a case where the plurality of through wirings 54, the plurality of through wirings 48, and the plurality of through wirings 47 are arranged side by side in 2 rows along the second direction H, respectively. For example, in four sensor pixels 12 sharing the first signal processing circuit 22A, four floating diffusion portions FD are arranged close to each other with the element separating portion 43 interposed therebetween. For example, in four sensor pixels 12 that share the first signal processing circuit 22A, four transfer gate electrodes TG (TG1, TG2, TG3, and TG4) are arranged so as to surround four floating diffusion portions FD, and the four transfer gate electrodes TG form a ring shape.

The insulating layer 53 includes a plurality of blocks extending along the second direction H. The semiconductor substrate 21 includes a plurality of island-shaped blocks 21A extending along the second direction H, and the plurality of island-shaped blocks 21A are arranged side by side along a first direction V orthogonal to the second direction H with an insulating layer 53 interposed therebetween. For example, each block 21A includes a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL. For example, one first signal processing circuit 22A shared by four sensor pixels 12 does not face the four sensor pixels 12, but is arranged with an offset in the first direction V.

In fig. 24, one first signal processing circuit 22A shared by four sensor pixels 12 includes a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL in a region of the second substrate 20 that is offset in the first direction V from a region opposed to the four sensor pixels 12. For example, one first signal processing circuit 22A shared by four sensor pixels 12 includes an amplifying transistor AMP, a reset transistor RST, and a selection transistor SEL within one block 21A.

In fig. 25, one first signal processing circuit 22A shared by four sensor pixels 12 includes a reset transistor RST, an amplification transistor AMP, a selection transistor SEL, and an FD transmission transistor FDG in a region of the second substrate 20 that is offset in the first direction V from a region opposed to the four sensor pixels 12. For example, one first signal processing circuit 22A shared by four sensor pixels 12 includes an amplifying transistor AMP, a reset transistor RST, a selection transistor SEL, and an FD transfer transistor FDG in one block 21A.

In the image pickup apparatus 1M, for example, one first signal processing circuit 22A shared by four sensor pixels 12 does not face the four sensor pixels 12, but is shifted in the first direction V from a position facing the four sensor pixels 12. In this case, it is possible to shorten the wiring 25 or omit the wiring 25, and it is allowed to configure the source of the amplifying transistor AMP and the drain of the selection transistor SEL to share one impurity region. As a result, the size of the first signal processing circuit 22A can be reduced, and the size of any other portion in the first signal processing circuit 22A can be increased.

Modification example N

The imaging device 1N as the modification N is a column ADC type imaging device. Fig. 26 shows an example of a cross-sectional configuration in the horizontal direction of an imaging apparatus 1N as a modification N. The imaging device 1N is a modification of the imaging device 1J. Fig. 26 shows a modification of the cross-sectional structure in fig. 16. Note that in the example in fig. 26, for example, the first signal processing circuit 22A includes an amplification transistor AMP, a reset transistor RST, and a selection transistor SEL. In the image pickup device 1N, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing 22A circuit, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

In the image pickup apparatus 1N, the semiconductor substrate 21 includes a plurality of island-shaped blocks 21A, the plurality of island-shaped blocks 21A being arranged side by side in the first direction V and the second direction H via the insulating layer 53. For example, each block 21A includes a set of a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL. In this case, crosstalk between the readout circuits 22 adjacent to each other can be suppressed by the insulating layer 53, and a reduction in resolution of a reproduced image and deterioration in image quality due to color mixing can be suppressed.

Modification example O

The imaging device 1O as the modification O is a column ADC type imaging device. Fig. 27 shows an example of a cross-sectional configuration in the horizontal direction of an imaging apparatus 1O as a modification O. The imaging device 1O is a modification of the imaging device 1N. Fig. 27 shows a modification of the cross-sectional structure in fig. 26. Note that in the example of fig. 27, for example, the first signal processing circuit 22A includes an amplifying transistor AMP, a reset transistor RST and a selection transistor SEL. In the image pickup device 1O, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

In the imaging apparatus 1O, for example, one first signal processing circuit 22A shared by four sensor pixels 12 does not face the four sensor pixels 12, but is offset in the first direction V. In the image pickup device 1O, as in the image pickup device 1N, the semiconductor substrate 21 includes a plurality of island-shaped blocks 21A arranged side by side in the first direction V and the second direction H via the insulating layer 53. For example, each block 21A includes a set of a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL. Further, in the imaging device 1O, the plurality of through wirings 47 and the plurality of through wirings 54 are also arranged side by side along the second direction H. Specifically, the plurality of through wirings 47 are arranged between four through wirings 54 in which a certain first signal processing circuit 22A is shared and four through wirings 54 in which another first signal processing circuit 22A adjacent to the certain first signal processing circuit 22A in the second direction H is shared. In this case, crosstalk between the first signal processing circuits 22A adjacent to each other can be suppressed by the insulating layer 53 and the through wiring 47, and a reduction in resolution of a reproduced image and deterioration in image quality due to color mixing can be suppressed.

Modification example P

The imaging device 1P as the modification P is a column ADC type imaging device. Fig. 28 shows an example of a cross-sectional configuration in the horizontal direction of an image pickup apparatus 1P as a modification P. The imaging device 1P is a modification of the imaging device 1J. Fig. 28 shows a modification of the cross-sectional structure in fig. 16. Note that in the example of fig. 28, for example, the first signal processing circuit 22A includes the amplifying transistor AMP, the transistor RST, and the selection transistor SEL. In the image pickup device 1P, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

In the image pickup apparatus 1P, the first substrate 10 includes a photodiode PD and a transfer transistor TX in each sensor pixel 12, and one floating diffusion FD is shared by every four sensor pixels 12. Therefore, in the imaging device 1P, one through wiring 54 is provided for every four sensor pixels 12.

Among the plurality of sensor pixels 12 arranged in a matrix, for convenience, four sensor pixels 12 corresponding to a region obtained by shifting a unit region corresponding to the four sensor pixels 12 sharing one floating diffusion FD by one sensor pixel 12 in the first direction V are referred to as "four sensor pixels 12A". In this case, in the imaging device 1P, one through wiring 47 is shared by every four sensor pixels 12A in the first substrate 10. Therefore, in the imaging device 1P, one through wiring 47 is provided for every four sensor pixels 12A.

In the imaging device 1P, the first substrate 10 includes an element separating portion 43 that separates the photodiode PD and the transfer transistor TX for each sensor pixel 12. The element separating portion 43 does not completely surround the sensor pixel 12 when viewed from the normal direction of the semiconductor substrate 11, and has a gap (non-formed region) in the vicinity of the floating diffusion FD (through wiring 54) and in the vicinity of the through wiring 47. This gap allows one through wiring 54 to be shared by four sensor pixels 12 and one through wiring 47 to be shared by four sensor pixels 12A. In the image pickup apparatus 1P, the second substrate 20 includes the first signal processing circuit 22A provided for every four sensor pixels 12 that share the floating diffusion FD.

Modification Q

The imaging device 1Q as the modification Q is a column ADC type imaging device. Fig. 29 shows an example of a cross-sectional configuration in the horizontal direction of an imaging apparatus 1Q as a modification Q. The imaging device 1Q is a modification of the imaging device 1N. Fig. 29 shows a modification of the cross-sectional structure in fig. 26. Note that in the example of fig. 29, for example, the first signal processing circuit 22A includes an amplification transistor AMP, a reset transistor RST, and a selection transistor SEL. In the image pickup device 1Q, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

In the image pickup apparatus 1Q, the first substrate 10 includes photodiodes PD and transfer transistors TX provided for the respective sensor pixels 12, and one floating diffusion FD is shared by every four sensor pixels 12. The first substrate 10 includes an element separating portion 43 that separates the photodiode PD and the transfer transistor TX for each sensor pixel 12.

Modification example R

The imaging device 1R as the modification R is a column ADC type imaging device. Fig. 30 shows an example of a cross-sectional configuration in the horizontal direction of an image pickup apparatus 1R as a modification R. The imaging device 1R is a modification of the imaging device 1O. Fig. 30 shows a modification of the cross-sectional structure in fig. 27. Note that, in the example of fig. 30, for example, the first signal processing circuit 22A includes the amplifying transistor AMP, the reset transistor RST, and the selection transistor SEL. In the image pickup device 1R, the analog transistors included in the first signal processing circuit 22A are arranged in the second substrate 20. Further, regarding the a/D converter connected to the subsequent stage of the readout circuit 22 including the first signal processing circuit 22A, in addition to the amplification transistor being arranged in the second substrate 20, the analog transistor included in a part of the a/D converter is also arranged in the second substrate 20.

In the image pickup apparatus 1R, the first substrate 10 includes photodiodes PD and transfer transistors TX provided for the respective sensor pixels 12, and one floating diffusion FD is shared by every four sensor pixels 12. The first substrate 10 includes an element separating portion 43 that separates the photodiode PD and the transfer transistor TX for each sensor pixel 12.

Modification example S

Fig. 31 shows an example of a circuit configuration of an image pickup apparatus 1S as a modification S. The imaging device 1S is a modification of the imaging devices 1 and 1A to 1R. The imaging device 1S is a CMOS image sensor including column-parallel ADCs.

As shown in fig. 31, the image pickup device 1S includes, in addition to a pixel region 13 in which a plurality of sensor pixels 12 each having a photoelectric converter are two-dimensionally arranged in rows and columns (i.e., in a matrix), a vertical drive circuit 33, a signal processing circuit 34, a reference voltage supply section 38, a horizontal drive circuit 35, a horizontal output line 37, and a system control circuit 36.

In this system configuration, the system control circuit 36 generates a clock signal, a control signal, and any other signals serving as references for the operations of the vertical drive circuit 33, the signal processing circuit 34, the reference voltage supply section 38, the horizontal drive circuit 35, and the like, based on the master clock MCK, and supplies these signals to the vertical drive circuit 33, the signal processing circuit 34, the reference voltage supply section 38, the horizontal drive circuit 35, and the like.

Further, the vertical driving circuit 33 is provided in the first substrate 10 together with the respective sensor pixels 12 in the pixel region 13, and also provided in the second substrate 20 in which the first signal processing circuit 22A included in the readout circuit 22 is formed. The signal processing circuit 34, the reference voltage supply section 38, the horizontal drive circuit 35, the horizontal output line 37, and the system control circuit 36 are provided in the third substrate 30.

Although not shown, the sensor pixel 12 may also use, for example, the following configuration: which includes, in addition to the photodiode PD, a transfer transistor TX that transfers charges obtained by photoelectric conversion in the photodiode PD to a floating diffusion FD. Further, although not shown, the readout circuit 22 may use, for example, a three-transistor configuration as follows: it includes a reset transistor RST for controlling the potential of the floating diffusion FD, an amplification transistor AMP for outputting a signal corresponding to the potential of the floating diffusion FD, and a selection transistor SEL for pixel selection.

In the pixel region 13, the sensor pixels 12 are two-dimensionally arranged, and one pixel drive line 23 is arranged row by row for a pixel array of m rows and n columns, and one vertical signal line 24 is arranged column by column for a pixel array of m rows and n columns. One ends of the plurality of pixel driving lines 23 are respectively connected to a corresponding one of respective output terminals of the vertical driving circuit 33 provided corresponding to the respective rows. The vertical drive circuit 33 includes a shift register and the like, and performs control of row address and row scanning of the pixel region 13 via a plurality of pixel drive lines 23.

For example, the signal processing circuit 34 includes analog-to-digital conversion circuits (ADCs) 34-1 to 34-m provided for respective pixel columns of the pixel region 13 (i.e., for respective vertical signal lines 24), converts analog signals output from the columns of the respective sensor pixels 12 in the pixel region 13 into digital signals, and outputs the digital signals. Note that as explained in the foregoing embodiment, ADCs (analog-to-digital conversion circuits) may be provided separately for the respective sensor pixels 12.

For example, the reference voltage supply section 38 includes a digital-to-analog conversion circuit (DAC) 38A as a means for generating a reference voltage Vref called a ramp waveform whose level changes obliquely with time. Note that the means for generating the reference voltage Vref of the ramp waveform is not limited to the DAC 38A.

Under the control of the control signal CS1 supplied from the system control circuit 36, the DAC 38A generates a reference voltage Vref of a ramp waveform based on the clock CK supplied from the system control circuit 36, and supplies the reference voltage Vref to the ADCs 34-1 to 34-m of the column processing section.

Note that each of the ADCs 34-1 to 34-m is allowed to selectively perform an a/D conversion operation corresponding to each operation mode. These modes of operation include: a normal frame rate mode in which a progressive scanning method of reading out information of all the sensor pixels 12 is adopted; and a high frame rate mode in which, for example, the exposure time of the sensor pixels 12 is set to 1/N to increase the frame rate by N times, for example, two times, as compared with the frame rate in the normal frame rate mode. This switching of the operation mode is performed by controlling the control signals CS2 and CS3 supplied from the system control circuit 36. Further, instruction information for switching between operation modes (i.e., the normal frame rate mode and the high frame rate mode) is supplied to the system control circuit 36 from an external system controller (not shown).

The ADCs 34-1 to 34-m all have the same configuration, and here, the ADC 34-m is exemplified. For example, the ADC 34-m includes a comparator 34A, an up/down counter (referred to as "U/D CNT" in the drawing) 34B serving as a counting means, a transfer switch 34C, and a memory 34D.

The comparator 34A compares the signal voltage Vx of the vertical signal line 24 corresponding to the signal output from each sensor pixel 12 in the nth column of the pixel region 13 with the reference voltage Vref of the ramp waveform supplied from the reference voltage supply section 38, and for example, shifts the output Vcc to an "H (high)" level in the case where the reference voltage Vref is greater than the signal voltage Vx, and for example, shifts the output Vcc to an "L (low)" level in the case where the reference voltage Vref is equal to or less than the signal voltage Vx.

The up/down counter (up-down counter)34B includes an asynchronous counter, and measures a comparison period from the start of the comparison operation to the end of the comparison operation in the comparator 34A by receiving a clock CK from the system control circuit 36 simultaneously with the DAC 38A and performing down-counting (down-counting) or up-counting (up-counting) in synchronization with the clock CK under the control of a control signal CS2 supplied from the system control circuit 36 a.

Specifically, in the normal frame rate mode, in the operation of reading signals from one sensor pixel 12, the comparison time at the time of the first readout is measured by performing down-counting in the first readout operation, and the comparison time at the time of the second readout is measured by performing up-counting in the second readout operation.

In contrast, in the high frame rate mode, the count results of the sensor pixels 12 in a certain row are saved as they are. Subsequently, for the sensor pixels 12 in the next row of the certain row, the comparison time at the time of the first readout is measured by performing down-counting in the first readout operation using the count result of the previous time, and the comparison time at the time of the second readout is measured by performing up-counting in the second readout operation.

In the normal frame rate mode, when the counting operation of the up/down counter 34B for the sensor pixels 12 in the certain row is completed, the transfer switch 34C is turned to an ON state under the control of the control signal CS3 supplied from the system control circuit 36, and the count result of the up/down counter 34B is transferred to the memory 34D.

In contrast, at a high frame rate of, for example, N ═ 2, when the counting operation of the up/down counter 34B to the sensor pixels 12 in the certain row is completed, the transfer switch 34C is maintained in the OFF (open) state. Subsequently, when the counting operation of the up/down counter 34B for the sensor pixels 12 in the next row of the certain row is completed, the transfer switch 34C is turned to the on state, and the count result of the up/down counter 34B with respect to two vertical pixels is transferred to the memory 34D.

As described above, the analog signals supplied column by column from the respective sensor pixels 12 in the pixel region 13 via the vertical signal lines 24 are converted into N-bit (N-bit) digital signals by the respective operations of the comparator 34A and the up/down counter 34B in the ADCs 34-1 to 34-m, and the digital signals are stored in the memory 34D.

The horizontal drive circuit 35 includes a shift register and the like, and performs control of column addresses and column scanning of the ADCs 34-1 to 34-m in the signal processing circuit 34. Under the control of the horizontal drive circuit 35, the N-bit digital signals obtained by a/D conversion in each of the ADCs 34-1 to 34-m are sequentially read out to the horizontal output line 37, and are output as image pickup data via the horizontal output line 37.

Note that, in addition to the above-described constituent elements, a circuit or the like which performs various signal processes on image pickup data output via the horizontal output line 37, which is not illustrated because it is not directly related to the present invention, may be provided.

In the image pickup apparatus 1S including the column-parallel ADC having the foregoing configuration, the count result of the up/down counter 34B can be selectively transferred to the memory 34D through the transfer switch 34C, which can independently control the counting operation of the up/down counter 34B and the readout operation of passing the count result of the up/down counter 34B to the horizontal output line 37.

Modification T

Fig. 32 shows an example of the configuration of an image pickup apparatus 1T as a modification T. The imaging device 1T is a modification of the imaging devices 1 and 1A to 1S. In the imaging device 1T, the first substrate 10 includes: a pixel region 13 including a plurality of sensor pixels 12 disposed at a central portion; and a vertical driving circuit 33 disposed around the pixel region 13. Further, in the second substrate 20, a readout circuit region 15 including a plurality of first signal processing circuits 22A is provided at a central portion, and a vertical driving circuit 33 is provided around the readout circuit region 15. The third substrate 30 is provided with a signal processing circuit 34, a horizontal driving circuit 35, a system control circuit 36, a horizontal output line 37, and a reference voltage supply unit 38. This prevents an increase in chip size and an obstruction to area miniaturization per pixel due to the configuration in which the substrates are electrically connected to each other, as in the foregoing embodiment and its modifications. As a result, the following image pickup apparatus 1 having a three-layer configuration can be provided: the three-layer construction has a chip size substantially equivalent to that before and does not hinder area miniaturization per pixel. Note that the vertical driving circuit 33 may be provided only in the first substrate 10, or may be provided only in the second substrate 20.

Modification example U

Fig. 33 shows an example of the configuration of an imaging apparatus 1U as a modification U. The imaging device 1U is a modification of the imaging devices 1 and 1A to 1T. Each of the aforementioned image pickup devices 1 and 1A to 1T is configured by laminating three substrates (a first substrate 10, a second substrate 20, and a third substrate 30). However, each of the aforementioned image pickup devices 1 and 1A to 1T may be configured by laminating two substrates (the first substrate 10 and the second substrate 20). In this case, for example, as shown in fig. 33, the logic circuit 32 is provided separately in the first substrate 10 and the second substrate 20. Here, the circuit 32A of the logic circuit 32 provided in the first substrate 10 includes transistors having the following gate structures: in the gate structure, a high dielectric constant film made of a material resistant to a high temperature process (for example, a high-k (high dielectric constant) material) and a metal gate electrode are stacked. On the other hand, in the circuit 32B of the logic circuit 32 provided in the second substrate 20, an impurity diffusion region including, for example, CoSi is provided on the front surface of the impurity diffusion region in contact with the source electrode and the drain electrode₂And a low resistance region 26 of silicide such as NiSi. The silicide is prepared using a salicide (self aligned silicide) process. Low current including silicideThe barrier region is formed of a compound containing a semiconductor substrate material and a metal. This allows the use of high temperature processes such as thermal oxidation used in forming the sensor pixels 12. Further, in the case where the low-resistance region 26 including silicide is provided on the front surface of the impurity diffusion region which is in contact with the source electrode and the drain electrode in the circuit 32B of the logic circuit 32 which is provided in the second electrode 20, the contact resistance can be reduced. As a result, the operation speed of the logic circuit 32 can be increased.

Modification example V

Fig. 34 shows an example of the configuration of an imaging apparatus 1V as a modification V. The imaging device 1V is a modification of the imaging devices 1 and 1A to 1T. In the logic circuit 32 of the third substrate 30 in any of the aforementioned image pickup devices 1 and 1A to 1T, an impurity diffusion region including, for example, CoSi may be provided on the front surface of the impurity diffusion region in contact with the source electrode and the drain electrode₂And a low-resistance region 37A of silicide such as NiSi. The silicide is prepared using a salicide (self aligned silicide) process. This allows the use of high temperature processes such as thermal oxidation used in forming the sensor pixels 12. Further, in the logic circuit 32, in the case where the low-resistance region 37A including silicide is provided on the front surface of the impurity diffusion region which is in contact with the source electrode and the drain electrode, the contact resistance can be reduced. As a result, the operation speed of the logic circuit 32 can be increased.

Modification example W

In the aforementioned image pickup devices 1 and 1A to 1V, the conductivity type may be reversed. For example, in the foregoing embodiment and modifications a to V, p-type may be replaced with n-type, and n-type may be replaced with p-type. Even in this case, effects similar to those of the above-described imaging apparatuses 1 and 1A to 1V can be obtained.

(3. application example)

Application example 1

The aforementioned image pickup apparatuses 1 and 1A to 1W (hereinafter, representatively referred to as "image pickup apparatus 1") can be applied to various types of electronic devices. Non-limiting examples of electronic devices include: cameras such as digital cameras and digital video cameras, mobile phones having an image pickup function, and any other devices having an image pickup function.

Fig. 35 is a block diagram showing an example of a schematic configuration of an electronic apparatus including the image pickup device 1 according to any one of the foregoing embodiments and modifications thereof.

An electronic apparatus 201 shown in fig. 35 includes an optical system 202, a shutter device 203, the image pickup device 1, a control circuit 205, a signal processing circuit 206, a monitor 207, and a memory 208, and is capable of shooting still images and moving images.

The optical system 202 includes at least one lens, and guides light (incident light) from a subject to the image pickup device 1 and forms an image on a light receiving surface of the image pickup device 1.

The shutter device 203 is disposed between the optical system 202 and the image pickup device 1, and controls an illumination period and a light shielding period to the image pickup device 1 according to control by the control circuit 205.

The imaging device 1 includes a package including the imaging device. The image pickup device 1 accumulates signal charges for a certain period of time corresponding to light imaged on the light receiving surface via the optical system 202 and the shutter device 203. The signal charges accumulated in the image pickup apparatus 1 are transferred in accordance with a drive signal (timing signal) supplied from the control circuit 205.

The control circuit 205 outputs a drive signal for controlling the transfer operation of the image pickup device 1 and the shutter operation of the shutter device 203 to drive the image pickup device 1 and the shutter device 203.

The signal processing circuit 206 performs various signal processes on the signal charges output from the image pickup apparatus 1. The image (image data) obtained by the signal processing circuit 206 is supplied to a monitor 207 to be displayed thereon or to a memory 208 to be stored (recorded) therein.

In the electronic apparatus 201 configured as above, the application of the image pickup device 1 enables image pickup with reduced noise in all pixels.

Application example 2

Fig. 36 shows an example of a schematic configuration of an image pickup system 2 including the aforementioned image pickup apparatus 1 and any one of 1A to 1W. Fig. 36 shows an image pickup apparatus 1 as a representative of the image pickup apparatuses 1 and 1A to 1W. Hereinafter, the image pickup apparatuses 1 and 1A to 1W are representatively referred to as "image pickup apparatus 1".

The camera system 2 includes, for example, an electronic apparatus. Non-limiting examples of electronic devices include: image pickup devices such as digital cameras and video cameras; and mobile terminal devices such as smart phones or tablet type terminals. For example, the image pickup system 2 includes the image pickup device 1 according to any one of the foregoing embodiments and modifications thereof, a DSP (digital signal processor) circuit 141, a frame memory 142, a display section 143, a storage section 144, an operation section 145, and a power supply section 146. In the image pickup system 2, the image pickup device 1, the DSP circuit 141, the frame memory 142, the display section 143, the storage section 144, the operation section 145, and the power supply section 146 according to any one of the foregoing embodiments and modifications thereof are connected to each other via a bus 147.

The image pickup apparatus 1 according to any one of the foregoing embodiments and the modifications thereof outputs image data corresponding to incident light. The DSP circuit 141 includes a signal processing circuit that processes a signal (image data) output from the image pickup apparatus 1 according to any one of the foregoing embodiments and modifications a to W. The frame memory 142 temporarily holds image data processed by the DSP circuit 141 in units of frames. The display section 143 includes, for example, a panel-type display device such as a liquid crystal panel or an organic Electro Luminescence (EL) panel, and displays a moving image or a still image captured by the image capturing device 1 according to any one of the foregoing embodiments and modifications thereof. The storage section 144 stores image data such as a moving image or a still image captured by the image capturing apparatus 1 according to any one of the foregoing embodiments and modifications thereof in a storage medium such as a semiconductor memory or a hard disk. The operation unit 145 provides operation instructions regarding various functions possessed by the imaging system 2 in accordance with user operations. The power supply section 146 supplies various kinds of power as necessary to the image pickup apparatus 1, the DSP circuit 141, the frame memory 142, the display section 143, the storage section 144, and the operation section 145 according to any one of the foregoing embodiments and modifications thereof. These power supplies serve as operation power supplies of the image pickup apparatus 1, the DSP circuit 141, the frame memory 142, the display section 143, the storage section 144, and the operation section 145 according to any one of the foregoing embodiments and modifications thereof.

Next, a description is given of an image capturing process in the image capturing system 2.

Fig. 37 shows an example of a flowchart of the image capturing operation in the image capturing system 2. The user operates the operation unit 145 to provide an instruction to start image capturing (step S101). After that, the operation unit 145 transmits an instruction for image capturing to the image capturing apparatus 1 (step S102). The image pickup apparatus 1 (specifically, the system control circuit 36) receives an instruction for image pickup, and performs image pickup in a predetermined image pickup manner (step S103).

The imaging device 1 outputs image data obtained by imaging to the DSP circuit 141. Here, the image data includes data of pixel signals of all pixels, which are generated based on the electric charges temporarily held in the floating diffusion FD. The DSP circuit 141 executes predetermined signal processing (e.g., noise reduction processing) based on the image data input from the image pickup device 1 (step S104). The DSP circuit 141 saves the image data subjected to the predetermined signal processing in the frame memory 142, and the frame memory 142 records the image data in the storage section 144 (step S105). Thus, image capturing in the image capturing system 2 is performed.

In the present application example, the image pickup apparatus 1 according to any one of the foregoing embodiments and modifications a to W is applied to the image pickup system 2. This makes it possible to miniaturize the size of the image pickup apparatus 1 or to improve the definition of the image pickup apparatus 1, thereby providing the image pickup system 2 having a miniaturized size or having high definition.

(application example)

Application example 1

The technique according to the embodiment of the present invention (present technique) can be applied to various products. For example, the technology according to the embodiment of the present invention can be implemented as an apparatus mounted on any kind of moving body. Non-limiting examples of moving bodies include automobiles, electric automobiles, hybrid automobiles, motorcycles, bicycles, any personal mobile device, airplanes, unmanned aerial vehicles (drones), ships, and robots.

Fig. 38 is a block diagram showing an example of a schematic configuration of a vehicle control system, which is one example of a mobile body control system to which the technique according to the embodiment of the invention can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. In the example shown in fig. 38, the vehicle control system 12000 includes a drive system control unit 12010, a vehicle body system control unit 12020, an exterior information detection unit 12030, an interior information detection unit 12040, and an integrated control unit 12050. Further, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound/image output unit 12052, and an in-vehicle network interface (I/F) 12053 are shown.

The drive system control unit 12010 controls the operation of the devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 functions as a control device of various devices such as: a driving force generating device such as an internal combustion engine or a driving motor for generating a driving force of the vehicle; a driving force transmission mechanism for transmitting a driving force to a wheel; a steering mechanism for adjusting a steering angle of the vehicle; and a brake device for generating a braking force of the vehicle, and the like.

The vehicle body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the vehicle body system control unit 12020 functions as a control device of various devices such as: a keyless entry system; a smart key system; a motorized window arrangement; or various lights such as headlights, tail lights, brake lights, turn signals, or fog lights. In this case, a radio wave or a signal of various switches transmitted from the portable device instead of the key may be input to the vehicle body system control unit 12020. The vehicle body system control unit 12020 receives these input radio waves or signals, and controls the door lock device, power window device, lamp, and the like of the vehicle.

Vehicle exterior information detection section 12030 detects information on the exterior of the vehicle on which vehicle control system 12000 is mounted. For example, the vehicle exterior information detection means 12030 is connected to the imaging unit 12031. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the outside of the vehicle and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 may perform object detection processing or distance detection processing on, for example, a person, a vehicle, an obstacle, a logo, or characters on a road surface.

The imaging unit 12031 is an optical sensor: which is capable of receiving light and outputting an electrical signal corresponding to the amount of light received. The imaging unit 12031 may output an electrical signal as an image or may output an electrical signal as distance measurement information. Further, the light received by the image pickup portion 12031 may be visible light, or may be non-visible light such as infrared light.

The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 for detecting the state of the driver. The driver state detection unit 12041 includes, for example, a camera for photographing the driver. The in-vehicle information detecting unit 12040 may calculate the degree of fatigue of the driver or the degree of concentration of the driver, or may determine whether the driver is dozing, based on the detection information input from the driver state detecting section 12041.

Based on the information on the outside or inside of the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, the microcomputer 12051 can calculate a control target value of the driving force generation device, the steering mechanism, or the brake device, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 may execute cooperative control aimed at realizing the functions of an Advanced Driver Assistance System (ADAS) including: collision avoidance or collision mitigation of the vehicle, following travel based on the inter-vehicle distance, vehicle speed maintenance travel, vehicle collision warning, or vehicle lane departure warning, etc.

In addition, based on the information on the outside or inside of the vehicle obtained by the outside-vehicle information detecting unit 12030 or the inside-vehicle information detecting unit 12040, the microcomputer 12051 can execute cooperative control for the purpose of automatic driving or the like for autonomously running the vehicle without depending on the operation of the driver by controlling the driving force generating device, the steering mechanism, the braking device, or the like.

In addition, based on the information on the outside of the vehicle obtained by the vehicle exterior information detection unit 12030, the microcomputer 12051 may output a control command to the vehicle body system control unit 12020. For example, the microcomputer 12051 can execute cooperative control intended for antiglare by controlling headlights to switch from high beam to low beam according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detecting means 12030.

The audio/video output unit 12052 transmits an output signal of at least one of audio and video to the following output devices: the output device can visually or audibly notify a passenger on the vehicle or the outside of the vehicle of information. In the example of fig. 38, as output devices, an audio speaker 12061, a display portion 12062, and an instrument panel 12063 are shown. For example, the display 12062 may include at least one of an on-board display and a flat-view display.

Fig. 39 is a diagram showing an example of the installation position of the imaging unit 12031.

In fig. 39, the image pickup portion 12031 includes image pickup portions 12101, 12102, 12103, 12104, and 12105.

The image pickup portions 12101, 12102, 12103, 12104, and 12105 are provided at, for example, respective positions at the nose, side mirrors, rear bumper, and trunk door of the vehicle 12100 and at a position at an upper portion of a cabin interior windshield. The camera 12101 provided to the nose and the camera 12105 provided to the upper portion of the vehicle cabin interior windshield mainly obtain a front image of the vehicle 12100. The image pickup portions 12102 and 12103 provided to the side mirrors mainly obtain side images of the vehicle 12100. An image pickup portion 12104 provided to a rear bumper or a trunk door mainly obtains a rear image of the vehicle 12100. The imaging portion 12105 provided to the upper portion of the windshield inside the vehicle compartment is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a signal light, a traffic sign, a lane, or the like.

Incidentally, fig. 39 shows an example of the imaging range of the imaging sections 12101 to 12104. The imaging range 12111 indicates an imaging range of the imaging unit 12101 provided to the nose. Imaging ranges 12112 and 12113 represent imaging ranges of the imaging portions 12102 and 12103 provided to the side mirrors, respectively. The imaging range 12114 indicates an imaging range of the imaging unit 12104 provided to the rear bumper or the trunk door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing image data captured by the image capturing sections 12101 to 12104.

At least one of the image pickup portions 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the image pickup sections 12101 to 12104 may be a stereo camera composed of a plurality of image pickup elements, or may be an image pickup element having pixels for phase difference detection.

For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can find the distance from each solid object in the imaging ranges 12111 to 12114 and the change in the distance with time (relative speed with respect to the vehicle 12100), thereby extracting the following solid objects as the preceding vehicles: specifically, the solid object is the closest solid object on the traveling path of the vehicle 12100, and is a solid object that travels at a predetermined speed (for example, equal to or greater than 0 km/h) in substantially the same direction as the vehicle 12100. Further, the microcomputer 12051 may set an inter-vehicle distance to be secured in advance from the preceding vehicle ahead, and execute automatic braking control (including following stop control), automatic acceleration control (including following start control), or the like. Therefore, it is possible to perform cooperative control for the purpose of automatic driving or the like for which the vehicle can autonomously travel without depending on the operation of the driver.

For example, based on the distance information obtained from the image pickup portions 12101 to 12104, the microcomputer 12051 may classify the three-dimensional object data on the three-dimensional object into three-dimensional object data of two-wheeled vehicles, ordinary vehicles, large-sized vehicles, pedestrians, utility poles, and other three-dimensional objects, extract the classified three-dimensional object data, and automatically avoid the obstacle using the extracted three-dimensional object data. For example, the microcomputer 12051 recognizes obstacles around the vehicle 12100 as the following two types: one is an obstacle that can be visually perceived by the driver of the vehicle 12100, and the other is an obstacle that is difficult for the driver of the vehicle 12100 to visually perceive. Then, the microcomputer 12051 determines a collision risk indicating the degree of risk of collision with each obstacle. In the case where the collision risk is equal to or higher than the set value and thus there is a possibility of collision, the microcomputer 12051 may output a warning to the driver via the audio speaker 12061 or the display portion 12062, and may perform forced deceleration or avoidance steering by the drive system control unit 12010. Thus, the microcomputer 12051 can function as driving assistance for avoiding a collision.

At least one of the image pickup portions 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in captured images of the image capturing sections 12101 to 12104. For example, such identification of a pedestrian is performed by the following process: a process of extracting feature points in the captured images of the image capturing sections 12101 to 12104 as infrared cameras; and a process of determining whether or not the object is a pedestrian by performing a pattern matching process on a series of feature points representing the outline of the object. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the image capturing sections 12101 to 12104 and thus identifies a pedestrian, the sound/image output section 12052 controls the display section 12062 to display a square contour line for emphasis in a superimposed manner on the identified pedestrian. The sound/image output portion 12052 may also control the display portion 12062 to display an icon or the like indicating a pedestrian at a desired position.

In the above, a description has been given of an example of a mobile body control system to which the technique according to the embodiment of the present invention is applicable. For example, the technique according to the embodiment of the present invention can be applied to the image pickup portion 12031 in the configuration described above. Specifically, the image pickup apparatus 1 according to the foregoing embodiment and its modifications can be applied to the image pickup section 12031. By applying the technique according to the embodiment of the present invention to the image pickup section 12031, a captured image with less noise and high definition can be obtained. Therefore, high-precision control can be performed using a captured image in the moving body control system.

Application example 2

Fig. 40 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technique according to the embodiment of the present invention (present technique) can be applied.

In fig. 40, a state in which an operator (doctor) 11131 is performing an operation on a patient 11132 on a bed 11133 using an endoscopic surgery system 11000 is shown. As shown in the drawing, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a veress tube 11111 and an energy device 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101, an area of a predetermined length from a distal end thereof is inserted into a body cavity of a patient 11132, and a camera 11102, which is connected to a proximal end of the lens barrel 11101. In the illustrated example, an endoscope 11100 is shown that includes a rigid endoscope having a rigid barrel 11101. However, endoscope 11100 may also comprise a flexible endoscope having a flexible lens barrel.

The lens barrel 11101 has an opening at its distal end, in which an objective lens is fitted. The light source device 11203 is connected to the endoscope 11100 so that light generated by the light source device 11203 is introduced into the distal end of the lens barrel through a light guide member extending inside the lens barrel 11101 and is irradiated onto an observation object in the body cavity of the patient 11132 through an objective lens. Note that the endoscope 11100 may be a direct-view endoscope, or may be a strabismus endoscope or a side-view endoscope.

An optical system and an image pickup element are provided inside the camera 11102 so that reflected light (observation light) from an observation target is condensed on the image pickup element by the optical system. Observation light is photoelectrically converted by an image pickup element to generate an electric signal corresponding to the observation light, that is, an image signal corresponding to an observation image. The image signal is transmitted as RAW (RAW) data to a Camera Control Unit (CCU) 11201.

The CCU 11201 includes a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), and the like, and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Further, for example, the CCU 11201 receives an image signal from the camera 11102, and performs various image processing such as development processing (demosaicing processing) on the image signal to display an image based on the image signal.

Under the control of the CCU 11201, the display device 11202 displays an image based on the image signal on which the image processing has been performed by the CCU 11201.

For example, the light source device 11203 includes a light source such as a Light Emitting Diode (LED), and supplies irradiation light when imaging a surgical field or the like to the endoscope 11100.

The input device 11204 is an input interface of the endoscopic surgical system 11000. The user can input various information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user can input a command or the like for changing the imaging conditions (the type, magnification, focal length, and the like of the irradiation light) of the endoscope 11100.

Treatment tool control device 11205 controls the driving of energy device 11112 to cauterize tissue, or incise tissue, or seal blood vessels, etc. The pneumoperitoneum device 11206 supplies gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to inflate the body cavity, thereby securing the field of view of the endoscope 11100 and securing the working space of the operator. The recorder 11207 is a device capable of recording various information related to the operation. The printer 11208 is a device capable of printing various information related to the operation in various forms such as text, images, or graphics.

Note that the light source device 11203 for supplying irradiation light when an operation region is imaged to the endoscope 11100 may be constituted by a white light source constituted by, for example, an LED, a laser light source, or a combination thereof. In the case where the white light source is configured by a combination of red, green, and blue (RGB) laser light sources, since the output intensity and the output timing of each color (each wavelength) can be controlled with high accuracy, white balance adjustment of a captured image can be performed by the light source device 11203. Further, in this case, if the laser beams from the respective RGB laser light sources are irradiated on the observation target in a time-division manner and the driving of the image pickup element of the camera 11102 is controlled in synchronization with the irradiation timing, the images corresponding to the respective R, G and B can also be picked up in a time-division manner. According to this method, a color image can be obtained even if no color filter is provided for the image pickup element.

Further, the intensity of light to be output may be changed at predetermined intervals to control the driving of the light source device 11203. By controlling the driving of the image pickup element of the camera 11102 in synchronization with the change timing of the intensity of light to acquire images in a time-division manner and synthesizing the images, it is possible to create an image of a high dynamic range that is free from underexposed shadows and overexposed highlights.

Further, the light source device 11203 may be configured to provide light of a predetermined wavelength band corresponding to a special light observation. For example, in special light observation, by irradiating light having a narrow band domain compared to irradiation light (i.e., white light) at the time of ordinary observation by utilizing wavelength dependence of light absorption in body tissue, so-called narrow band domain light observation (narrow band domain imaging) is performed with high contrast on a predetermined tissue such as blood vessels of a mucosal surface layer portion. Alternatively, in the special light observation, fluorescence observation for obtaining an image from fluorescence generated by irradiation of excitation light may be performed. In the fluorescence observation, for example, the fluorescence observation of the body tissue (autofluorescence observation) may be performed by irradiating excitation light onto the body tissue, or a fluorescence image may be obtained by locally injecting an agent such as indocyanine green (ICG) into the body tissue and irradiating excitation light corresponding to a fluorescence wavelength of the agent onto the body tissue. The light source device 11203 may be configured to provide such narrow-band light and/or excitation light suitable for special light viewing as described above.

Fig. 41 is a block diagram showing an example of the functional configuration of the camera 11102 and the CCU 11201 shown in fig. 40.

The camera 11102 includes a lens unit 11401, an image pickup unit 11402, a drive unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are connected by a transmission cable 11400 to communicate with each other.

The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. Observation light taken from the distal end of the lens barrel 11101 is guided to the camera 11102 and introduced into the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focus lens.

The number of image pickup elements included in the image pickup unit 11402 may be one (single-plate type) or a plurality (multi-plate type). For example, in the case where the image pickup unit 11402 is configured of a multi-plate type, image signals corresponding to R, G and B are generated by the respective image pickup elements, and these image signals may be synthesized to obtain a color image. The image pickup unit 11402 may also be configured to have a pair of image pickup elements for acquiring a right-eye image signal and a left-eye image signal corresponding to three-dimensional (3D) display. If the 3D display is performed, the operator 11131 can grasp the depth of the living tissue in the operation region more accurately. Note that in the case where the image pickup unit 11402 is configured of a multi-plate type, a system in which a plurality of lens units 11401 are provided corresponding to respective image pickup elements is provided.

Further, the image pickup unit 11402 is not necessarily provided on the camera 11102. For example, the image pickup unit 11402 may be disposed inside the lens barrel 11101 and immediately after the objective lens.

The driving unit 11403 includes an actuator, and causes the zoom lens and the focus lens of the lens unit 11401 to move by a predetermined distance along the optical axis under the control of the camera control unit 11405. Therefore, the magnification and focus of the captured image of the image capturing unit 11402 can be appropriately adjusted.

A communication unit 11404 includes a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal acquired from the image pickup unit 11402 to the CCU 11201 as RAW data via the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal for controlling driving of the camera 11102 from the CCU 11201, and supplies the control signal to the camera control unit 11405. The control signal includes the following information related to the imaging condition: for example, information for specifying the frame rate of a captured image, information for specifying the exposure value at the time of image capturing, and/or information for specifying the magnification and focus of a captured image, and the like.

Note that the above-described image pickup conditions such as the frame rate, exposure value, magnification, or focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, an Auto Exposure (AE) function, an Auto Focus (AF) function, and an Auto White Balance (AWB) function are equipped in the endoscope 11100.

The camera control unit 11405 controls driving of the camera 11102 based on a control signal from the CCU 11201 received via the communication unit 11404.

The communication unit 11411 includes a communication device for transmitting and receiving various information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 via the transmission cable 11400.

Further, the communication unit 11411 transmits a control signal for controlling driving of the camera 11102 to the camera 11102. The image signal and the control signal may be transmitted by electrical communication, optical communication, or the like.

The image processing unit 11412 performs various image processes on the image signal in the form of RAW data transmitted from the camera 11102.

The control unit 11413 executes various controls related to image capturing of an operation region or the like by the endoscope 11100 and display of a captured image obtained by image capturing of the operation region or the like. For example, the control unit 11413 generates a control signal for controlling driving of the camera 11102.

Further, the control unit 11413 controls the display device 11202 to display a captured image in which the surgical region and the like are reflected, based on the image signal on which the image processing unit 11412 has performed the image processing. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 may recognize a surgical tool such as a forceps, a specific living body part, bleeding, mist when the energy device 11112 is used, or the like by detecting the shape, color, or the like of the edge of an object included in a captured image. When controlling the display device 11202 to display the captured image, the control unit 11413 may display various kinds of operation support information on the image of the operation region in an overlapping manner using the recognized result. In the case where the operation support information is displayed in an overlapping manner and presented to the operator 11131, the burden on the operator 11131 can be reduced and the operator 11131 can reliably perform the operation.

The transmission cable 11400 connecting the camera 11102 and the CCU 11201 to each other is an electrical signal cable suitable for electrical signal communication, an optical fiber suitable for optical communication, or a composite cable suitable for electrical communication and optical communication.

Here, although in the illustrated example, communication is performed by wired communication using the transmission cable 11400, communication between the camera 11102 and the CCU 11201 may be performed by wireless communication.

In the above, a description has been given of an example of an endoscopic surgical system to which the technique according to the embodiment of the present invention can be applied. The technique according to the embodiment of the present invention can be preferably applied to the image pickup unit 11402 provided in the camera 11102 of the endoscope 11100 in the above-described configuration. Applying the technique according to the embodiment of the present invention to the image pickup unit 11402, it is possible to reduce the size of the image pickup unit 11402 or improve the definition of the image pickup unit 11402. Therefore, the endoscope 11100 having a miniaturized size or having high definition can be provided.

Although the description has been made with reference to the embodiments, the modifications a to W, the application examples, and the application examples, the present invention is not limited thereto, and may be modified in various ways.

In the foregoing embodiments, the configuration in which the analog transistor including the amplifying transistor is disposed in the second substrate has been explained; however, the present invention is not limited to this, and instead of this configuration, a configuration may be applied in which analog transistors other than the amplifying transistor are arranged in the second substrate.

Note that the effects described in this specification are illustrative and not restrictive. The present invention may have effects other than those described in the present specification.

Note that the present technology may have the following configuration. In the present technology having the following configuration, the sensor pixel is arranged in the first substrate, and the analog transistor is arranged in the second substrate, which makes it possible to increase the dedicated area of the analog transistor without reducing the dedicated area of the photodiode and to reduce noise.

(1) An image pickup apparatus provided with a laminated structure including:

a first substrate including sensor pixels that perform photoelectric conversion and output signal charges;

a second substrate including a first signal processing circuit included in a readout circuit, the first signal processing circuit including a first analog transistor, the readout circuit outputting a pixel signal based on the signal charge; and

a third substrate including a logic circuit that processes the pixel signal,

wherein the first substrate, the second substrate and the third substrate are sequentially stacked.

(2) The image pickup apparatus according to (1), wherein,

the first substrate further includes a floating diffusion accumulating the signal charge, and

the first analog transistor includes an amplifying transistor whose gate electrode is connected to the floating diffusion.

(3) The image pickup apparatus according to at least one of (1) to (2),

the sensor pixel includes a plurality of sensor pixels, and

the readout circuit includes one analog-to-digital conversion circuit provided for each of the plurality of sensor pixels.

(4) The image pickup apparatus according to at least one of (1) to (3),

the readout circuit includes an analog-to-digital conversion circuit including a comparison circuit, and

the first analog transistor is included in the comparison circuit.

(5) The image pickup apparatus according to (1) or (4), wherein,

the sensor pixel comprises a plurality of sensor pixels,

the plurality of sensor pixels are arranged in rows and columns, and

the readout circuit includes: and one analog-to-digital conversion circuit provided for each column of the plurality of sensor pixels.

(6) The image pickup apparatus according to at least one of (1) to (5),

the readout circuit includes a vertical signal line, and

the first analog transistor includes a load transistor connected to the vertical signal line.

(7) The image pickup apparatus according to at least one of (1) to (6),

the readout circuit includes a sample-and-hold circuit,

the first analog transistor includes: an input transistor included in the sample-and-hold circuit.

(8) The image pickup apparatus according to at least one of (1) to (7),

the first analog transistor includes:

a channel forming region provided in the semiconductor region of the second substrate,

a gate insulating film provided on the channel forming region,

a gate electrode disposed on the gate insulating film,

a source region provided in the semiconductor region of the second substrate at a position adjacent to the channel formation region,

a drain region provided in the semiconductor region of the second substrate at a position adjacent to the channel formation region on a side opposite to the source region of the channel formation region,

a first metal silicide layer disposed to cover a front surface of the gate electrode,

a second metal silicide layer disposed to cover a front surface of the source region, an

A third metal silicide layer disposed to cover a front surface of the drain region.

(9) The image pickup apparatus according to at least one of (1) to (8),

the third substrate includes a second signal processing circuit included in the readout circuit together with the first signal processing circuit, and the second signal processing circuit includes a second analog transistor.

(10) The image pickup apparatus according to at least one of (1) to (9), wherein the first analog transistor includes an NMOS transistor.

(11) The image pickup apparatus according to at least one of (1) to (9), wherein the first analog transistor includes an NMOS transistor and a PMOS transistor.

(12) The image pickup device according to at least one of (1) to (11), wherein the sensor pixels each include a photodiode and a transfer transistor.

(13) The image pickup apparatus according to at least one of (1) to (12), wherein the readout circuit includes at least one of an amplification transistor, a reset transistor, and a selection transistor.

(14) The image pickup apparatus according to at least one of (1) to (13), wherein the readout circuit includes a part of an analog-to-digital conversion circuit.

(15) The image pickup apparatus according to at least one of (1) to (14), wherein the logic circuit includes a part of an analog-to-digital conversion circuit.

(16) The image pickup apparatus according to at least one of (1) to (15), wherein,

the sensor pixel includes a plurality of sensor pixels, and

the first substrate includes the plurality of sensor pixels, and includes an element separating portion that separates the plurality of sensor pixels.

(17) The image pickup apparatus according to at least one of (1) to (16),

the sensor pixel comprises a plurality of sensor pixels,

the first substrate includes the plurality of sensor pixels, and

the readout circuit is electrically connected to the plurality of sensor pixels.

(18) The image pickup apparatus according to at least one of (1) to (17), wherein,

the sensor pixel includes a plurality of sensor pixels, and

the first substrate includes one floating diffusion provided for each of the plurality of sensor pixels.

(19) The image pickup apparatus according to at least one of (1) to (17), wherein,

the sensor pixel includes a plurality of sensor pixels, and

the first substrate includes the plurality of sensor pixels, and includes one floating diffusion provided for the plurality of sensor pixels.

(20) An electronic device, comprising:

an optical system;

a camera device; and

a signal processing circuit for processing the signal received from the signal receiving circuit,

the imaging device is provided with a laminated structure including a first substrate, a second substrate, and a third substrate laminated in this order,

the first substrate includes sensor pixels that perform photoelectric conversion and output signal charges,

the second substrate includes a first signal processing circuit included in a readout circuit including a first analog transistor, the readout circuit outputs a pixel signal based on the signal charge, and

the third substrate includes a logic circuit that processes the pixel signal.

(21) An image pickup apparatus comprising:

a first substrate including at least one sensor portion that converts light into electric charges;

a second substrate including a first portion of a readout circuit including at least one first transistor, the readout circuit outputting a pixel signal based on the charge; and

a third substrate including a logic circuit that processes the pixel signal,

wherein the first substrate, the second substrate, and the third substrate are stacked in this order.

(22) The image pickup apparatus according to (21), wherein,

the first substrate further includes a floating diffusion portion that accumulates the charge, and

the at least one first transistor includes an amplification transistor whose gate electrode is connected to the floating diffusion.

(23) The image pickup apparatus according to at least one of (21) to (22), wherein,

the at least one sensor part includes a plurality of sensor parts, and

the readout circuit includes analog-to-digital conversion circuits provided for the respective sensor sections.

(24) The image pickup apparatus according to at least one of (21) to (23), wherein,

the readout circuit comprises a first part of an analog-to-digital conversion circuit, which contains a comparison circuit, and

the at least one first transistor is included in the comparison circuit.

(25) The image pickup apparatus according to at least one of (21) to (24),

the at least one sensor portion comprises a plurality of sensor portions,

the plurality of sensor sections are arranged in rows and columns, and

the readout circuit includes analog-to-digital conversion circuits provided for the respective columns of the plurality of sensor units.

(26) The image pickup apparatus according to at least one of (21) to (25), wherein,

the readout circuit includes a vertical signal line, and

the at least one first transistor includes a load transistor connected to the vertical signal line.

(27) The image pickup apparatus according to at least one of (21) to (26), wherein,

the readout circuit includes a sample-and-hold circuit,

the at least one first transistor includes: an input transistor included in the sample-and-hold circuit.

(28) The image pickup apparatus according to at least one of (21) to (27), wherein,

the at least one first transistor includes:

a channel region disposed in the semiconductor region of the second substrate,

a gate insulating film disposed on the channel region,

a gate electrode disposed on the gate insulating film,

a source region disposed in the semiconductor region of the second substrate at a position adjacent to the channel region,

a drain region provided in the semiconductor region of the second substrate at a position adjacent to the channel region on a side of the channel region opposite to the source region,

a first metal layer disposed to cover a front surface of the gate electrode,

a second metal layer disposed to cover a front surface of the source region, an

A third metal layer disposed to cover a front surface of the drain region.

(29) The image pickup apparatus according to at least one of (21) to (28), wherein,

the third substrate includes a second portion of the readout circuitry, the second portion of the readout circuitry is connected with the first portion of the readout circuitry, and the second portion of the readout circuitry includes a second transistor.

(30) The image pickup apparatus according to at least one of (21) to (29), wherein,

the at least one first transistor comprises an NMOS transistor and/or a PMOS transistor, and

the at least one first transistor receives and outputs an analog signal based on the charge, and the second transistor receives and outputs a digital signal based on the analog signal.

(31) The image pickup apparatus according to at least one of (21) to (30), wherein the at least one sensor section includes: a plurality of sensor sections sharing the at least one first transistor.

(32) The image pickup apparatus according to at least one of (21) to (31), wherein the at least one sensor section includes a photodiode and a transfer transistor.

(33) The image pickup apparatus according to at least one of (21) to (32), wherein the readout circuit includes at least one of an amplification transistor, a reset transistor, and a selection transistor.

(34) The image pickup apparatus according to at least one of (21) to (33), wherein,

the first part of the readout circuit comprises a first part of an analog-to-digital conversion circuit and the logic circuit comprises a second part of the analog-to-digital conversion circuit, and

a first portion of the analog-to-digital conversion circuit receives an analog signal based on the charge and a second portion of the analog-to-digital conversion circuit outputs a digital signal based on the analog signal.

(35) The image pickup apparatus according to at least one of (21) to (34), wherein the at least one sensor section includes a plurality of sensor sections that share a first portion of the analog-to-digital conversion circuit and a second portion of the analog-to-digital conversion circuit.

(36) The image pickup apparatus according to at least one of (21) to (35), wherein,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes the plurality of sensor portions, and includes an isolation region separating the plurality of sensor portions.

(37) The image pickup device according to at least one of (21) to (36), wherein,

the at least one sensor portion comprises a plurality of sensor portions,

the first substrate includes the plurality of sensor portions, and

the readout circuit is electrically connected to the plurality of sensor units.

(38) The image pickup apparatus according to at least one of (21) to (37), wherein,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes: and a floating diffusion portion provided for each of the plurality of sensor portions.

(39) The image pickup apparatus according to at least one of (21) to (38), wherein,

the at least one sensor part includes a plurality of sensor parts, and

the first substrate includes the plurality of sensor portions, and includes a floating diffusion portion shared by the plurality of sensor portions.

(40) An electronic device, comprising:

an optical system;

a camera device; and

a signal processing circuit for processing the signal received from the signal receiving circuit,

the image pickup apparatus includes:

a first substrate including at least one sensor portion that converts light into electric charges;

a second substrate including a first portion of a readout circuit including at least one first transistor, the readout circuit outputting a pixel signal based on the charge; and

a third substrate including a logic circuit that processes the pixel signal,

wherein the first substrate, the second substrate, and the third substrate are stacked in this order.

It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and changes may be made in accordance with design requirements and other factors insofar as they come within the scope of the appended claims or the equivalents thereof.

[ list of reference numerals ]

1: image pickup apparatus

10: first substrate

11: semiconductor substrate

12: sensor pixel

13: pixel region

20: second substrate

21: semiconductor substrate

22: readout circuit

22A: first signal processing circuit

22B: second signal processing circuit

23: pixel driving line

24: vertical signal line

24A: signal readout line

30: third substrate

31: semiconductor substrate

32: logic circuit

33: vertical driving circuit

34: signal processing circuit

35: horizontal driving circuit

36: system control circuit

PD: photodiode

TX: transmission transistor

FD: floating diffusion part

AMP: amplifying transistor

REF: reference signal input transistor

Vb: current source transistor

PTR1, PTR 2: transistor with a metal gate electrode

RST: reset transistor

SEL: selection transistor