阅读说明：本技术 一种像素结构、cis和终端 (Pixel structure, CIS and terminal ) 是由 杨鑫 于 2019-09-16 设计创作，主要内容包括：本申请实施例公开了一种像素结构,该像素结构包括第一层PD、第二层PD、第一读出电路和第二读出电路,第一层PD包括一种PD,一种PD分别用于对接收到的入射光中对应的特定波长的光进行共振吸收和光电转换,得到两种特定波长的光对应的电信号,第二层PD放置于第一层PD的一侧,第二层PD包括两种PD,两种PD用于对经过第一层PD共振吸收后的入射光中一一对应的两种特定波长的光,进行共振吸收和光电转换,得到两种特定波长的光对应的电信号,第一读出电路读出一种特定波长的光对应的电信号,第二读出电路分别读出两种特定波长的光对应的电信号。本申请实施例还同时提供了一种CIS和终端。(The embodiment of the application discloses a pixel structure, which comprises a first layer PD, a second layer PD, a first reading circuit and a second reading circuit, wherein the first layer PD comprises a PD, the PDs are respectively used for carrying out resonance absorption and photoelectric conversion on light with corresponding specific wavelengths in received incident light to obtain electric signals corresponding to the light with the two specific wavelengths, the second layer PD is placed on one side of the first layer PD and comprises two PDs, the two PDs are used for carrying out resonance absorption and photoelectric conversion on light with the two specific wavelengths in the incident light after the resonance absorption of the first layer PD to obtain electric signals corresponding to the light with the two specific wavelengths, the first reading circuit reads out the electric signals corresponding to the light with the one specific wavelength, and the second reading circuit reads out the electric signals corresponding to the light with the two specific wavelengths. The embodiment of the application also provides a CIS and a terminal.)

1. A pixel structure comprising a first layer of Photodiodes (PD), a second layer of PDs, a first readout circuitry connected to the first layer of PDs and a second readout circuitry connected to the second layer of PDs; wherein the content of the first and second substances,

the first layer PD comprises a PD, and the PD is used for performing resonance absorption and photoelectric conversion on light with a corresponding specific wavelength in received incident light to obtain an electric signal corresponding to the light with the specific wavelength;

the second layer PD is arranged on one side of the first layer PD, and comprises two PDs which are used for performing resonance absorption and photoelectric conversion on two kinds of light with specific wavelengths which correspond to each other in incident light subjected to resonance absorption by the first layer PD to obtain electric signals corresponding to the two kinds of light with specific wavelengths;

the first reading circuits respectively read the electric signals corresponding to the light with the specific wavelength;

the second reading circuit reads out the electric signals corresponding to the two lights with the specific wavelengths;

wherein any two PDs in the first layer PD and the second layer PD are different from each other.

2. The pixel structure according to claim 1, wherein when the first layer PD comprises a first type PD, the second layer PD comprises a second type PD and a third type PD;

the first PD is used for carrying out resonance absorption on light with a first specific wavelength in the received incident light according to the resonance wavelength of a light receiving surface of the first PD, and carrying out photoelectric conversion on the absorbed light to obtain an electric signal corresponding to the light with the first specific wavelength;

the second PD is used for performing resonance absorption on light with a second specific wavelength in the received incident light subjected to resonance absorption by the first layer PD according to the resonance wavelength of the light receiving surface of the second PD, and performing photoelectric conversion on the absorbed light to obtain an electric signal corresponding to the light with the second specific wavelength;

the third PD is configured to perform resonance absorption on light with a third specific wavelength in the received incident light subjected to resonance absorption by the first layer PD according to a resonance wavelength of a light receiving surface of the third PD, and perform photoelectric conversion on the absorbed light to obtain an electrical signal corresponding to the light with the third specific wavelength;

the first readout circuit reads out an electric signal corresponding to the light with the first specific wavelength;

the second readout circuit reads out the electrical signal corresponding to the light with the second specific wavelength and the electrical signal corresponding to the light with the third specific wavelength respectively;

wherein a resonance wavelength of a light receiving face of each of the first, second, and third PDs is a wavelength at which the light receiving face of the each PD undergoes resonance absorption.

3. The pixel structure according to claim 2, wherein the first specific wavelength, the second specific wavelength and the third specific wavelength comprise:

any one combination of the following three wavelengths: red, green, blue wavelengths.

4. The pixel structure of claim 2, wherein the shape of the light receiving face of each PD comprises any one of: circular, square, triangular, pentagonal, and hexagonal.

5. The pixel structure of claim 4, wherein the volume of each PD is a cylinder;

wherein the light receiving surface of each PD is one of the circular bottom surfaces of the cylinder; the resonance wavelength of the light receiving surface of each PD has a positive correlation with the diameter of the circular bottom surface.

6. The pixel structure of claim 5,

the diameter of the light receiving face of the PD for resonance absorption of blue light wavelength is 60 nm;

alternatively, the diameter of the light receiving face of the PD for resonance absorption of a red wavelength is 120 nm;

alternatively, the diameter of the light receiving surface of the PD for resonance absorption of a green wavelength is 90 nm.

7. The pixel structure of claim 1, further comprising a filter disposed on another side of the first layer PD, wherein,

the optical filter is used for receiving the incident light and transmitting the incident light to the first layer PD.

8. The pixel structure according to claim 1, wherein the second layer PD further comprises a charge transfer circuit connected to the first layer PD; wherein the content of the first and second substances,

the charge transfer circuit is configured to transfer the electrical signal obtained by the first layer PD to the first readout circuit.

9. A cmos image sensor CIS, characterized in that it comprises a pixel structure according to any one of the preceding claims 1 to 8.

10. A terminal characterized in that it comprises a CIS as claimed in claim 9 above.

Technical Field

The present invention relates to a pixel structure of a complementary metal Oxide Semiconductor Image Sensor (CIS) in a terminal, and more particularly, to a pixel structure, a CIS, and a terminal.

Background

Generally, a digital camera using a Charge-coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS) is capable of recording only one of three colors of Red, Green and Blue (RGB) on the same pixel structure, currently, Foveon X3 is the first image sensor in the world capable of capturing all colors on one pixel structure, Foveon X3 uses a three-layer stacked photosensitive element, and measures signals obtained at different depths by using the difference of absorption lengths of light with different wavelengths in silicon, each layer records one of color channels of RGB, and finally, the detection of three colors of R, G, and B is realized in one pixel structure.

However, the Foveon X3 adopts a three-layer laminated photosensitive element, which has high process difficulty, high power consumption and serious spectral crosstalk, and affects the quality of signals obtained by a pixel structure, and further affects the imaging quality of the CIS.

Disclosure of Invention

The embodiment of the application provides a pixel structure, a CIS and a terminal, and aims to improve the signal quality of an electric signal obtained by the pixel structure.

The technical scheme of the application is realized as follows:

the embodiment of the application provides a pixel structure, which comprises a first layer PD, a second layer PD, a first readout circuit connected with the first layer PD and a second readout circuit connected with the second layer PD; wherein the content of the first and second substances,

the first layer PD comprises a PD, and the PD is used for performing resonance absorption and photoelectric conversion on light with a corresponding specific wavelength in received incident light to obtain an electric signal corresponding to the light with the specific wavelength;

the second layer PD is arranged on one side of the first layer PD, and comprises two PDs which are used for performing resonance absorption and photoelectric conversion on the light with two corresponding specific wavelengths in the incident light subjected to resonance absorption by the first layer PD to obtain electric signals corresponding to the light with the two specific wavelengths;

the first reading circuits respectively read the electric signals corresponding to the light with the specific wavelength;

the second reading circuit reads out the electric signals corresponding to the two lights with the specific wavelengths;

wherein any two PDs in the first layer PD and the second layer PD are different from each other.

The embodiment of the application also provides a CIS, which comprises the pixel structure described in one or more embodiments.

The embodiment of the application further provides a terminal, and the terminal comprises the CIS in one or more embodiments.

The embodiment of the application provides a pixel structure, a CIS and a terminal, the pixel structure comprises a first layer PD, a second layer PD, a first readout circuit connected with the first layer PD and a second readout circuit connected with the second layer PD, wherein the first layer PD comprises a PD, the PD is used for performing resonance absorption and photoelectric conversion on light with a corresponding specific wavelength in received incident light to obtain an electric signal corresponding to the light with the specific wavelength, the second layer PD is arranged on one side of the first layer PD and comprises two PDs, the two PDs are respectively used for performing resonance absorption and photoelectric conversion on light with two specific wavelengths in the incident light after the resonance absorption of the first layer PD to obtain electric signals corresponding to the light with the two specific wavelengths, any two PDs in the first layer PD and the second layer PD are different from each other, the first readout circuit respectively reads out the electric signals corresponding to the light with the specific wavelength, the second reading circuit reads out the electric signals corresponding to the light with two specific wavelengths; that is to say, in the embodiment of the present application, one PD is disposed in the first PD layer, and two PDs different from the one PD are disposed in the second PD layer, so that the pixel structure can perform resonance absorption and photoelectric conversion on incident light in a layered manner, and thus, electrical signals corresponding to light with three specific wavelengths can be obtained, and the problems of high process difficulty, high power consumption and serious crosstalk caused by using a conventional three-layer stacked structure are avoided, so that the quality of signals obtained by the pixel structure is improved, and the imaging quality of the CIS is improved.

Drawings

FIG. 1 is a schematic diagram of wavelength dependence on absorption coefficient and penetration depth, respectively;

FIG. 2 is a schematic cross-sectional view of Foveon X3;

fig. 3 is a schematic structural diagram of an alternative pixel structure according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an example of an alternative optical filter provided in an embodiment of the present disclosure;

fig. 5A is a schematic structural diagram of an example of an alternative pixel structure provided in an embodiment of the present application;

fig. 5B is a schematic structural diagram of an example of another alternative pixel structure provided in the embodiments of the present application;

fig. 5C is a schematic structural diagram of an example of yet another alternative pixel structure provided in the embodiments of the present application;

fig. 6 is a schematic cross-sectional view of an example of an alternative pixel structure provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of an example of yet another alternative pixel structure provided in an embodiment of the present application;

fig. 8 is a schematic structural diagram of an alternative CIS provided in an embodiment of the present application;

fig. 9 is a schematic structural diagram of an alternative terminal according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.