阅读说明：本技术 半导体装置和成像装置 (Semiconductor device and imaging device ) 是由 琴尾健吾 小池薫 于 2016-04-26 设计创作，主要内容包括：本发明提高了半导体芯片之间的接合强度。在半导体装置中,第一半导体芯片设置有第一接合面,第一接合面包括：第一绝缘层；与通过第一绝缘层而被绝缘的第一内层电路电连接的多个第一焊盘；和布置在多个第一焊盘的外部的线状的第一金属层。第二半导体芯片包括接合至第一接合面的第二接合面,第二接合面包括：第二绝缘层；布置在与第一焊盘面对的位置处且与通过第二绝缘层而被绝缘的第二内层电路电连接的多个第二焊盘；和布置在与第一金属层面对的位置处的线状的第二金属层。第一金属层和第二金属层的宽度是基于从第一半导体芯片的端部至第一焊盘的区域中的第一绝缘层与第二绝缘层之间的接合强度和第一金属层与第二金属层之间的接合强度的宽度。(The invention improves the bonding strength between the semiconductor chips. In a semiconductor device, a first semiconductor chip is provided with a first bonding surface including: a first insulating layer; a plurality of first pads electrically connected to the first inner layer circuit insulated by the first insulating layer; and a first metal layer in a line shape disposed outside the plurality of first pads. The second semiconductor chip includes a second bonding surface bonded to the first bonding surface, the second bonding surface including: a second insulating layer; a plurality of second pads arranged at positions facing the first pads and electrically connected to a second inner layer circuit insulated by a second insulating layer; and a second metal layer arranged in a line shape at a position facing the first metal layer. The widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region from an end portion of the first semiconductor chip to the first pad.)

1. A semiconductor device, comprising:

a first semiconductor chip including a first bonding surface including

A first insulating layer, a second insulating layer,

a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and

a first metal layer in a line shape, the first metal layer being arranged outside the plurality of first pads; and

a second semiconductor chip including a second bonding surface bonded to the first bonding surface, the second bonding surface including

A second insulating layer is formed on the first insulating layer,

a plurality of second pads which are arranged at positions facing the first pads and to which a second inner layer circuit insulated by the second insulating layer is electrically connected, and

a second metal layer in a line shape, the second metal layer being arranged at a position facing the first metal layer,

wherein widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region from an end of the first semiconductor chip to the first pad.

2. The semiconductor device according to claim 1, wherein the first and second electrodes are formed on a substrate,

wherein widths of the first metal layer and the second metal layer are widths based on an average of a bonding strength between the first insulating layer and the second insulating layer in the region and a bonding strength between the first metal layer and the second metal layer.

3. The semiconductor device as set forth in claim 2,

wherein the widths of the first and second metal layers are substantially equal to a width Q satisfying the following relation,

(x×P+y×Q)/R>z

wherein the content of the first and second substances,

z: a bonding strength per unit area between the first semiconductor chip and the second semiconductor chip,

x: a bonding strength per unit area between the first insulating layer and the second insulating layer,

y: a bonding strength per unit area between the first metal layer and the second metal layer,

p: a length of a joint portion of the first insulating layer and the second insulating layer on a path substantially perpendicularly intersecting with an end portion of the first semiconductor chip, and

r: a length between the first pad on the path and an end of the first semiconductor chip.

4. The semiconductor device according to claim 3, wherein the first and second semiconductor layers are stacked,

wherein the path is a path that: which substantially perpendicularly intersects an end portion of the first semiconductor chip and extends from the end portion of the first semiconductor chip and first reaches the first pad.

5. The semiconductor device according to claim 4, wherein the first and second semiconductor layers are stacked,

wherein the path is a path having the longest distance among such paths: substantially perpendicularly intersects an end portion of the first semiconductor chip, and extends from the end portion of the first semiconductor chip and first reaches the first pad.

6. The semiconductor device according to any one of claims 1 to 5,

wherein the first bonding surface further includes a first dummy pad not electrically connected to the first inner layer circuit,

the second bonding surface further includes a second dummy pad arranged at a position facing the first dummy pad and not electrically connected to the second inner layer circuit, and

widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip and reaching first the first pad or the first dummy pad.

7. The semiconductor device according to any one of claims 1 to 5,

wherein the first metal layer and the second metal layer are divided into a predetermined number of parts.

8. The semiconductor device according to any one of claims 1 to 5,

wherein the first semiconductor chip and the second semiconductor chip are configured in a rectangular shape, and

widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in the region for each side of each of the first semiconductor chip and the second semiconductor chip.

9. An imaging device includes a first semiconductor chip and a second semiconductor chip,

the first semiconductor chip includes a first bonding surface and a first diffusion layer,

the first engagement surface comprises

A first insulating layer, a second insulating layer,

a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and

a first metal layer in a line shape, the first metal layer being arranged outside the plurality of first pads,

the first diffusion layer includes a semiconductor region that is electrically connected to the first inner layer circuit and converts applied light into an electric signal; and is

The second semiconductor chip bonded to the first bonding surface, the second semiconductor chip including a second bonding surface and a second diffusion layer,

the second engagement surface comprises

A second insulating layer is formed on the first insulating layer,

a plurality of second pads which are arranged at positions facing the first pads and to which a second inner layer circuit insulated by the second insulating layer is electrically connected, and

a second metal layer in a line shape, the second metal layer being arranged at a position facing the first metal layer,

the second diffusion layer includes a semiconductor region electrically connected to the second inner layer circuit and processing the electric signal,

wherein widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip to the first pad.

Technical Field

The invention relates to a semiconductor device and an imaging device. More particularly, the present invention relates to a semiconductor device and an imaging device formed by bonding two semiconductor chips.

Background

Heretofore, a semiconductor device has been used which: a plurality of semiconductor chips are stacked to form a three-dimensional configuration, and thus miniaturization is achieved. For example, in the imaging device, the light receiving element chip and the peripheral circuit chip are separately manufactured based on respective manufacturing processes. The light receiving element chip is a semiconductor chip having such a configuration: wherein pixels each including a light receiving element are arranged in a two-dimensional array configuration. The peripheral circuit chip is formed of a peripheral circuit that drives the light receiving element chip. Thereafter, the following production method was used: these chips are bonded together and stacked, thereby constructing an imaging device. In the case of using this manufacturing method, it is desirable to enhance the bonding strength at the bonding surface to improve the reliability of the imaging device.

On the bonding surface of the chip, a pad electrically connected to a circuit in the semiconductor chip is arranged; and the transmission of electrical signals between chips can be achieved through these bonded pads. The pad is made of metal such as copper (Cu), and thus relatively high bonding strength can be obtained. On the other hand, an insulating layer for insulating the pad and the like is arranged in a region other than the pad of the bonding surface. The bonding strength between the insulating layers is lower than that between the bonding pads; therefore, a system for activating the bonding surface by plasma treatment to improve the bonding strength has been proposed (for example, see patent document 1).

Reference list

Patent document

Patent document 1: japanese patent laid-open No. 5-082404

Disclosure of Invention

Technical problem to be solved by the invention

The conventional technique described above has an effect of improving the bonding strength between insulating films on the bonding surfaces by activation, but on the other hand, has a problem that: the pad is damaged and deteriorated, and copper (Cu) constituting the pad is scattered around and an apparatus for bonding the semiconductor chip is contaminated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve bonding strength between semiconductor chips without performing an activation treatment of a bonding surface.

Solution to the technical problem

The present invention is conceived to solve the above-described problems, and a first aspect of the present invention is a semiconductor device including: a first semiconductor chip including a first bonding surface including a first insulating layer, a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and a linear first metal layer arranged outside the plurality of first pads; and a second semiconductor chip including a second bonding surface bonded to the first bonding surface, the second bonding surface including a second insulating layer, a plurality of second pads arranged at positions facing the first pads and electrically connected to a second inner layer circuit insulated by the second insulating layer, and a second metal layer in a linear shape arranged at positions facing the first metal layer. Widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region from an end portion of the first semiconductor chip to the first pad. This produces the following effect: the first metal layer and the second metal layer are arranged with a width based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region from an end portion of the first semiconductor chip to the first pad.

Further, according to the first aspect, the widths of the first metal layer and the second metal layer may be a width based on an average of a bonding strength between the first insulating layer and the second insulating layer in the region and a bonding strength between the first metal layer and the second metal layer. This produces the following effect: the first metal layer and the second metal layer having a width based on an average of a bonding strength between the first insulating layer and the second insulating layer in the region and a bonding strength between the first metal layer and the second metal layer are arranged.

Further, according to the first aspect, the widths of the first metal layer and the second metal layer may be substantially equal to a width Q satisfying the following relation, (x × P + y × Q)/R > z, where z: bonding strength per unit area between the first semiconductor chip and the second semiconductor chip, x: bonding strength per unit area between the first insulating layer and the second insulating layer, y: a bonding strength per unit area between the first metal layer and the second metal layer, P: a length of a joint of the first insulating layer and the second insulating layer on a path substantially perpendicularly intersecting with an end portion of the first semiconductor chip, and R: a length between the first pad on the path and an end of the first semiconductor chip. This produces the following effect: the first metal layer and the second metal layer are arranged with a width based on a length of a joint of the first insulating layer and the second insulating layer on a path substantially perpendicularly intersecting with an end portion of the first semiconductor chip and a width based on other factors.

Further, according to the first aspect, the path may be a path that: substantially perpendicularly intersects an end portion of the first semiconductor chip, and extends from the end portion of the first semiconductor chip and first reaches the first pad. This produces the following effect: the first metal layer and the second metal layer are arranged with a width based on the length of the joint of the first insulating layer and the second insulating layer on the shortest path between the end portion of the first semiconductor chip and the first pad and based on other factors.

Further, according to the first aspect, the path may be a path having the longest distance among such paths: substantially perpendicularly intersects an end portion of the first semiconductor chip, and extends from the end portion of the first semiconductor chip and first reaches the first pad. This produces the following effect: the first and second metal layers are arranged to have widths based on the lengths of the junctions of the first and second insulating layers on the path having the minimum bonding strength and based on other factors.

Further, according to the first aspect, the first bonding surface may further include a first dummy pad that is not electrically connected to the first inner layer circuit. The second bonding surface may further include a second dummy pad arranged at a position facing the first dummy pad and not electrically connected to the second inner layer circuit. Widths of the first metal layer and the second metal layer may be widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip and reaching first the first pad or the first dummy pad. This produces the following effect: the first metal layer and the second metal layer are arranged with a width based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end portion of the first semiconductor chip and reaching first the first pad or the first dummy pad.

Further, according to the first aspect, the first metal layer and the second metal layer may be divided into a prescribed number of parts. This produces the following effect: and partitioning the first metal layer and the second metal layer.

Further, according to the first aspect, the first semiconductor chip and the second semiconductor chip may be configured in a rectangular shape. The widths of the first and second metal layers may be widths based on a bonding strength between the first and second insulating layers and a bonding strength between the first and second metal layers in the region for each side of each of the first and second semiconductor chips. This produces the following effect: the first metal layer and the second metal layer are arranged with widths based on a bonding strength between the first insulating layer and the second insulating layer in the region and a bonding strength of the first metal layer and the second metal layer for each side of each of the semiconductor chips.

Further, a second aspect of the present invention is an image forming apparatus comprising: a first semiconductor chip including a first bonding surface and a first diffusion layer, the first bonding surface including a first insulating layer, a plurality of first pads electrically connected to a first inner layer circuit insulated by the first insulating layer, and a linear first metal layer arranged outside the plurality of first pads, the first diffusion layer including a semiconductor region electrically connected to the first inner layer circuit and converting applied light into an electrical signal; and a second semiconductor chip bonded to the first bonding surface, the second semiconductor chip including a second bonding surface and a second diffusion layer, the second bonding surface including a second insulating layer, a plurality of second pads arranged at positions facing the first pads and electrically connected to a second inner layer circuit insulated by the second insulating layer, and a second metal layer in a linear shape arranged at positions facing the first metal layer, the second diffusion layer including a semiconductor region electrically connected to the second inner layer circuit and processing the electric signal. Widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip to the first pad. This produces the following effect: the first metal layer and the second metal layer are arranged with a width based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in such a region as to extend from an end portion of the first semiconductor chip to the first pad.

The invention has the advantages of

According to the present invention, a favorable effect of improving the bonding strength between semiconductor chips can be exhibited without performing an activation treatment of the bonding surface. Note that the effects described herein are not necessarily restrictive, and any effects to be described in the present invention may be exhibited.

Drawings

Fig. 1 shows a configuration example of a semiconductor device 10 in a first embodiment of the present invention.

Fig. 2 shows a configuration example of a semiconductor chip in a first embodiment of the present invention.

Fig. 3 shows the width of the guard ring in the first embodiment of the present invention.

Fig. 4 shows an offset or the like during alignment in the first embodiment of the present invention.

Fig. 5 shows the width of the guard ring in a modification of the first embodiment of the present invention.

Fig. 6 shows a guard ring in a second embodiment of the invention.

Fig. 7 shows a configuration example of the semiconductor device 10 in the third embodiment of the present invention.

Fig. 8 shows a dummy pad in a third embodiment of the present invention.

FIG. 9 shows a design procedure for a guard ring in an embodiment of the invention.

Fig. 10 shows a maximum insulator joint length calculation procedure (step S910) in the embodiment of the present invention.

Detailed Description

Hereinafter, an embodiment for carrying out the present invention (hereinafter, referred to as an embodiment) is explained. The description is given in the following order.

1. First embodiment (example of case of using guard ring)

2. Second embodiment (example of case of dividing guard ring)

3. Third embodiment (example of case of using dummy pad)

<1. first embodiment >

[ Structure of semiconductor device ]

Fig. 1 shows a configuration example of a semiconductor device 10 in a first embodiment of the present invention. The figure is a cross-sectional view of the configuration of an imaging apparatus for a camera or the like. The configuration of the semiconductor device 10 in the embodiment of the present invention will now be described using this imaging device as an example. The semiconductor device 10 includes a first semiconductor chip 100 and a second semiconductor chip 200. Further, the semiconductor device 10 is constituted by bonding the first semiconductor chip 100 and the second semiconductor chip 200 together at the "B" position shown in the drawing. Further, the semiconductor device 10 is an example of the imaging device described in claims.

The first semiconductor chip 100 converts an image into an electrical signal. In the first semiconductor chip 100, pixels (not shown) that generate electric signals according to applied light are arranged in a two-dimensional array configuration. The electric signals generated by the pixels are output to the second semiconductor chip 200. The first semiconductor chip 100 includes microlenses 101, color filters 102, a first diffusion layer 110, a wiring layer 131, via holes 132, a first insulating layer 129, a first pad 124, and a first protective ring 121.

The microlens 101 forms an optical image on the above-described pixel. The color filter 102 is an optical filter for causing light of a desired wavelength to be incident on the pixel.

The first diffusion layer 110 is a semiconductor region where the pixels are generated. A microlens 101 and a color filter 102 are arranged in each pixel.

The wiring layer 131 transmits electrical signals. The wiring layer 131 is wired for each of a plurality of pixels arranged in an XY matrix configuration formed in the first diffusion layer 110. Supply of electric power, input of control signals, and output of electric signals to/from the pixels are performed via the wiring layer 131. The wiring layer 131 may be stacked in a plurality of layers. The figure shows an example of the wiring layer 131 stacked in three layers. The via hole 132 electrically connects wiring layers 131 arranged in different layers. For example, copper (Cu) may be used for the wiring layer 131 and the via hole 132. Further, the wiring layer 131 and the via hole 132 constitute a first interlayer circuit.

The first insulating layer 129 insulates the wiring layer 131 and the via hole 132. The first insulating layer 129 is bonded to a second insulating layer 229 which will be described later. For example, silicon dioxide (SiO)₂[0]) Or a silicone glass may be used for the first insulating layer 129.

The first pads 124 are electrically connected to the wiring layer 131 and the via holes 132, and mutually transmit electrical signals with the second semiconductor chip 200. In the first semiconductor chip 100, the number of first pads corresponding to a signal to be transmitted may be arranged. Further, the first pad 124 is bonded to a second pad 224 described later. For example, copper (Cu) may be used for the first pad 124.

The first guard ring 121 is a linear metal layer disposed outside the first pad. Further, the first protection ring 121 is joined to a second protection ring 221 described later. The first protection ring 121 may be electrically connected to the wiring layer 131 and the via hole 132, and may be connected to, for example, a ground conductor. Further, the first protection ring 121 may not be connected to the wiring layer 131 and the via hole 132, and may be an electrically independent configuration. For example, copper (Cu) may be used for the first guard ring 121. Further, the first guard ring 121 is an example of the first metal layer described in the claims.

The second semiconductor chip 200 is electrically and mechanically bonded to the first semiconductor chip 100, and generation of control signals of pixels of the first semiconductor chip 100, processing of electrical signals generated by the pixels, and the like are performed. An example of this processing includes analog/digital conversion of converting an analog electrical signal generated by the first semiconductor chip 100 into a digital electrical signal. The second semiconductor chip 200 includes a second diffusion layer 210, a wiring layer 231, a via hole 232, a second insulating layer 229, a second pad 224, and a second guard ring 221.

The second diffusion layer 210 is a semiconductor region in which generation of the control signal, processing of an electric signal, and the like are performed. The electrical signal processed by the semiconductor region is output to the outside of the semiconductor device 10 as an image signal.

The wiring layer 231 transmits an electrical signal. Similarly to the wiring layer 131, the wiring layer 231 may be stacked as a plurality of layers. The figure shows an example of the wiring layer 231 stacked in four layers. The via hole 232 electrically connects the wiring layers 231 arranged in different layers. For example, copper (Cu) may be used for the wiring layer 231 and the via hole 232. Further, the wiring layer 231 and the via hole 232 constitute a second interlayer circuit.

The second insulating layer 229 insulates the wiring layer 231 and the via hole 232. As described above, the second insulating layer 229 is bonded to the first insulating layer 129. For example, silicon dioxide (SiO)₂[0]) Or silicone glass may be used for the second insulating layer 229.

The second pad 224 is electrically connected to the wiring layer 231 and the via hole 232, and mutually transmits an electrical signal with the first semiconductor chip 100. As described above, the second pad 224 is bonded to the first pad 124. For example, copper (Cu) may be used for the first pad 224.

The second guard ring 221 is a linear metal layer disposed outside the second pad. As described above, the second protection ring 221 is bonded to the first protection ring 121. For example, copper (Cu) may be used for the second guard ring 221. Further, the second guard ring 221 is an example of the claimed second metal layer.

[ Structure of semiconductor chip ]

Fig. 2 shows a configuration example of a semiconductor chip in a first embodiment of the present invention. The figure shows the configuration of the first semiconductor chip 100 and the second semiconductor chip 200 before being bonded together. A of the present drawing shows the configuration of the bonding surface 120 (the surface indicated by the broken line of a of the present drawing) of the second semiconductor chip 200, and b of the present drawing shows the bonding surface 220 (the surface indicated by the broken line of b of the present drawing) of the second semiconductor chip 200. Both semiconductor chips have bonding surfaces of rectangular shape.

The first insulating layer 129, the first pad 124, and the first guard ring 121 are disposed on the bonding surface 120.

The first pads 124 are arranged in the shape of islands embedded in the first insulating layer 129. Further, the first protection ring 121 is disposed in a shape surrounding the edge of the engagement surface 120.

The second insulating layer 229, the second pad 224, and the second guard ring 221 are disposed on the junction surface 220.

The second pads 224 are arranged in the shape of islands embedded in the second insulating layer 229. Further, the second pads 224 are arranged in positions symmetrical to the first pads 124. The second guard ring 221 is disposed in a shape surrounding the edge of the joint face 220.

The first engagement face 120 and the second engagement face 220 are engaged together. In this case, the first pad 124 and the second pad 224 are bonded together, the first insulating layer 129 and the second insulating layer 229 are bonded together, and the first guard ring 121 and the second guard ring 221 are bonded together. The joining method is described later.

The bond strength between metal features, such as first bond pad 124 and second bond pad 224, is typically relatively high. On the other hand, the bonding strength between the first insulating layer 129 and the second insulating layer 229 occupying most of the bonding surface is relatively low. When the activation treatment is performed, the bonding strength between the insulating layers can be improved, but a problem similar to the above is caused. Therefore, by arranging the first and second protection rings 121 and 221 on the joint surface and increasing the area of the joint portion of the metal member in the joint surface, a desired joint strength can be obtained. Further, by arranging the first protection ring 121 and the second protection ring 221 in a shape surrounding the end edges of the joint surfaces 120 and 220, respectively, there is an effect of preventing the end of the joint surfaces from transmitting cracks. At the end of the joint face, generally, stress concentrates and therefore cracking is likely to occur. Therefore, by arranging the guard ring 221 or the like at the end portion to improve the bonding strength, the occurrence of cracking can be prevented.

[ Width of guard Ring ]

Fig. 3 shows the width of the guard ring in the first embodiment of the present invention. The figure shows a method of calculating the widths of the first and second guard rings 121 and 221. A in the drawing shows a front view of an end portion of the first semiconductor chip 100, and b in the drawing shows a cross-sectional view of a bonding portion of the semiconductor device 10.

As described above, the bonding strength between the insulating layers is lower than that between metal members such as the first pad 124 and the second pad 224. The first pad 124 and the like are generally arranged in a region away from the peripheral portion of the first semiconductor chip 100 and the like where stress concentrates. Therefore, by disposing the guard ring 121 and the like in the peripheral portion of the first semiconductor chip 100 and the like, the lack of bonding strength can be compensated. Here, the widths of the first and second guard rings 121 and 221 are denoted as Q. Q can be calculated from the bonding strength between the first insulating layer 129 and the second insulating layer 229 and the bonding strength between the first guard ring 121 and the second guard ring 221 in the region extending from the end of the first semiconductor chip 100 to the first pad 124.

If the first pad 124 marked with C of a in the figure is explained as an example, Q can be calculated from the bonding strength between the insulating layers and the bonding strength between the guard rings in the region extending from the end of the first semiconductor chip 100 to the first pad 124. Here, the length of the joint portion of the insulating layer in this region is denoted as P. In order to obtain a desired bonding strength in the first semiconductor chip 100 and the second semiconductor chip 200, it is necessary to set the average bonding strength of the insulating layer portion and the bonding strength of the guard ring portion in this region described above to a value exceeding the desired bonding strength described above. Here, the desired bonding strength between the first semiconductor chip 100 and the second semiconductor chip 200 is a bonding strength set in consideration of reliability and the like required for the semiconductor device 10, and is a value expressed by a bonding strength per unit area between these semiconductor chips.

If the desired bond strength is represented by z, then the relationship between z and P, Q is shown below.

(x × P + y × Q)/R > z … formula 1

Here, x represents the bonding strength per unit area between the first insulating layer 129 and the second insulating layer 229. Y represents the bonding strength per unit area between the first protective ring and the second protective ring. R denotes a length between the first pad 124 and the end of the first semiconductor chip 100. In the figure, R is a length equal to the sum of P and Q. The left side of equation 1 expresses such mathematical operations: the total value of the bonding strength per unit length (unit length in the vertical direction of a in the present figure) in this region described above is divided by R to calculate an average value of the bonding strength in this region.

As illustrated in fig. 2, the bonding surface of the first semiconductor chip 100 and the second semiconductor chip 200 is rectangular in shape. Therefore, the calculation of Q is performed for four sides. Further, a value different from edge to edge may be used as the value of Q. Further, the maximum value of Q calculated for all sides may be used as a Q value common to four sides.

Further, as shown in a of the present drawing, the length of the joint portion of the first insulating layer 129 and the second insulating layer 229 on the path substantially perpendicularly intersecting with the end portion of the first semiconductor chip 100 may be used as P described above. Further, a path on which the first pad 124 is not inserted may also be selected. For example, for the first pad 124 marked with D in a of the present drawing, the first pad 124 marked with E is inserted on a path leading to the end of the first semiconductor chip 100. Therefore, P' associated with the path is excluded from the calculation of the joining strength. In this case, the calculation of Q is performed using the first pad 124 labeled with E. Therefore, Q can be calculated more accurately.

Further, Q is preferably calculated from the longest path among the paths on which the above-described first pad 124 is not inserted. The portion of P having the longest portion corresponds to the portion of the insulating layer having the longest joint. Therefore, since Q is calculated using the portion where the bonding strength is the smallest as a reference, this can further improve the calculation accuracy of Q.

[ case of taking into account a shift during alignment, etc. ]

Fig. 4 shows a shift during alignment and the like in the first embodiment of the present invention. A of the figure shows an example of a case where the alignment shift e1 occurs during the bonding of the first semiconductor chip 100 and the second semiconductor chip 200. In this case, the length of the joint portion of the first protective ring 121 and the second protective ring 221 is reduced. Therefore, it is necessary to manufacture the first guard ring 121 and the second guard ring 221 after adding e1 to Q.

In addition, b of the figure shows an example of a case where a dicing shift e2 occurs when the semiconductor device 10 is diced from a wafer. Here, b 401 of the figure shows the cutting position. In this case, it is also necessary to add e2 to Q to prevent a reduction in the area of the joint of the first protective ring 121 and the second protective ring 221.

[ method for manufacturing semiconductor device ]

The semiconductor device 10 can be manufactured by the following procedure. The first semiconductor chip 100 and the second semiconductor chip 200 including the first guard ring 121 and the second guard ring 221 having the width of Q calculated in the above-described manner are manufactured. These chips can be manufactured by a common semiconductor chip manufacturing method. Further, the first and second guard rings 121 and 221 can be manufactured by the same manufacturing method as the first and second pads 124 and 224. Next, the first bonding surface 120 of the first semiconductor chip 100 and the bonding surface 220 of the second semiconductor chip 200 are polished to make the bonding surfaces smooth. A Chemical Mechanical Polishing (CMP) method may be used for polishing. Next, alignment of the first semiconductor chip 100 and the second semiconductor chip 200 is performed to perform bonding of the bonding surfaces. Heating is performed to a temperature of 300 to 600 ℃ in an adhesive state, and thus the two chips are bonded together. Thus, the semiconductor device 10 can be manufactured.

Therefore, in the first embodiment of the present invention, the bonding surface of the semiconductor chip is provided with the first guard ring 121 and the second guard ring 221. As the guard ring, a guard ring having such a width is used: the width is calculated from the strength of the bonding portion of the insulating layer and the strength of the bonding portion of the guard ring in the region extending from the end portion of the first semiconductor chip 100 to the first pad 124. Therefore, the bonding strength of the semiconductor device 10 can be set to a desired bonding strength.

[ first modification ]

In the above-described embodiment, the first protection ring 121 and the second protection ring 221 are configured to have the same width. In contrast, the widths of the first and second guard rings 121 and 221 may be set to different values. This is to absorb errors during manufacturing, such as alignment shifts and the like.

Fig. 5 shows the width of the guard ring in a modification of the first embodiment of the present invention. The figure shows an example of a case where the widths of the first protection ring 121 and the second protection ring 221 are different. In this case, too, a desired bonding strength can be obtained by setting the length of the bonding portion of the first protective ring 121 and the second protective ring 221 to a value equal to Q.

<2 > second embodiment

In the above-described embodiments, one guard ring is used per semiconductor chip. In contrast, in the second embodiment of the present invention, the guard ring is divided, and a plurality of guard rings are used. Therefore, generation of defects during CMP polishing is prevented.

[ Structure of guard Ring ]

Fig. 6 shows a guard ring in a second embodiment of the invention. As described above, in the manufacturing process of the semiconductor device 10, the polishing of the bonding surface of the semiconductor chip by the CMP method is performed. In this case, if the widths Q of the first and second guard rings 121 and 221 are excessively large, there is a case where a so-called dishing defect (disking) in which the guard ring portion is excessively cut off occurs. To prevent this, as shown in the present drawing, the first protection ring 121 and the second protection ring 221 are cut and arranged. The figure shows an example where each guard ring is divided into four. In this case, the sum of the widths of the guard rings divided is set to be equal to Q. In addition, the configuration of the semiconductor device 10 is similar to the semiconductor device 10 described in fig. 1, and thus, the description is omitted.

Therefore, in the second embodiment of the present invention, by dividing the guard ring, it is possible to prevent the occurrence of the dishing defect during CMP polishing while maintaining a desired bonding strength.

<3. third embodiment >

In the above-described embodiment, Q is calculated from the strength of the joint portion of the insulating layer in the region extending from the end portion of the first semiconductor chip 100 to the first pad 124 and other factors. In contrast, in the third embodiment of the present invention, a dummy pad is added to the bonding surface to use a region from the end of the first semiconductor chip 100 to the first pad 124 or the dummy pad, thereby calculating Q. Therefore, Q can be reduced while maintaining the bonding strength.

[ Structure of semiconductor device ]

Fig. 7 shows a configuration example of the semiconductor device 10 in the third embodiment of the present invention. The semiconductor device 10 of this figure differs from the semiconductor device 10 described in fig. 1 in that: the first dummy pad 125 and the second dummy pad 225 are disposed in the first semiconductor chip 100 and the second semiconductor chip 200, respectively.

[ Structure of dummy pad ]

Fig. 8 shows a dummy pad in a third embodiment of the present invention. In the first embodiment of the present invention, Q is calculated from the bonding strength between the insulator members in the region from the end portion of the first semiconductor chip 100 to the first pad 124 and other factors. However, as shown in the upper diagram in the figure, when the distance between the first pad 124 and the end portion of the first semiconductor chip 100 is large, the value of Q is large. Thus, the following situation arises: the first guard ring 121 is close to the other first pads and violates the design rule. Therefore, as shown in the lower diagram in the figure, the first dummy pad 125 is arranged between the first pad 124 and the end portion of the first semiconductor chip 100. The first dummy pad 125 is arranged on the bonding surface 120, but is not connected to the wiring layer 131 and the via hole 132, and is an electrically independent pad.

Further, the dummy pads 225 are arranged in positions on the bonding face 220 facing the first dummy pads 125. Further, Q is calculated from the bonding strength between the insulating layers and the bonding strength between the guard rings in the region extending from the end of the first semiconductor chip 100 and reaching the first pad 124 or the first dummy pad 125 first. By adding the first dummy pad 125 and the second dummy pad 225, P can be shortened and Q based thereon can also be shortened. Thus, violation of design rules can be avoided. In addition, the configuration of the semiconductor device 10 is similar to the semiconductor device 10 described in fig. 1, and thus, the description is omitted.

[ design procedure for guard Ring ]

FIG. 9 shows a design procedure for a guard ring in an embodiment of the invention. The figure shows a design procedure for a guard ring comprising the following steps: the steps include the addition of dummy pads and the segmentation of guard rings. First, the maximum insulator joint length is calculated (step S910). Here, the maximum insulator joint length is the maximum value of P. Next, the width of the guard ring is calculated from the maximum insulator bonding length (step S901). This can be calculated by equation 1 above. Next, whether the width of the guard ring meets the design rule is judged (step S902). Here, rules related to the use of the CMP method are included in the design rules. Therefore, in the case where the design rule is satisfied (YES in step S902), the position of the guard ring is determined (step S903), and the design of the guard ring is completed.

On the other hand, in the case where the design rule is not met (step S902: NO), it is judged whether or not the guard ring and the pad interfere with each other (step S904). That is, whether the distance between the guard ring and the pad is appropriate is evaluated. Therefore, in the case where the guard ring and the pad interfere with each other (YES in step S904), a dummy pad is added (step S906), and the process from step S910 is executed again. On the other hand, in the case where the guard ring and the pad do not interfere with each other (step S904: NO), the guard ring is divided (step S905), and the procedure from step S910 is executed again.

Fig. 10 shows a maximum insulator joint length calculation procedure (step S910) in the embodiment of the present invention. First, the maximum insulator joining length (Pmax) is initialized to a value of 0 (step S911). Next, the side of the semiconductor chip is selected (step S912), and the pad is selected (step S913). It is judged whether or not there is another pad between the selected pad and the selected edge (step S914). In the case where there is another pad (step S914: YES), the procedure returns to step S913 again, and another pad is selected. On the other hand, in the case where there is no other pad (step S914: NO), P described in FIG. 3 is calculated (step S915). The calculated P is compared to Pmax. In the case where P is larger than Pmax (YES in step S916), Pmax is changed to P (step S917), and the process goes to the process of step S918. On the other hand, in the case where P is Pmax or smaller (step S916: NO), the process of step S917 is skipped, and the process goes to the process of step S918.

In step S918, it is judged whether or not there is a next pad (step S918). That is, it is judged whether or not the calculation of P has been performed for all the pads. In the case where the next pad exists (step S918: yes), the procedure from step S913 on is executed again. On the other hand, in the case where there is no next pad (step S918: NO), it is judged whether or not there is a next edge (step S919). That is, it is evaluated whether the calculation of Pmax has been performed for all edges. Therefore, in the case where the next edge exists, the procedure from step S912 is executed again. On the other hand, in the case where the next edge does not exist, the maximum insulator joint length calculation routine is completed.

Therefore, in the third embodiment of the present invention, by adding dummy pads, it is possible to avoid violating the design rule while maintaining the desired bonding strength.

As described above, in the embodiment of the present invention, the guard ring having the following width is arranged on the joint face and used: the width is calculated from the strength of the bonding portion of the insulating layer and the strength of the bonding portion of the guard ring in the region from the end of the semiconductor chip to the pad. Therefore, the bonding strength of the semiconductor device can be set to a desired bonding strength without performing an activation process of the bonding surface.

The above-described embodiments are examples for embodying the present invention, and matters in the embodiments have correspondence with matters specifically disclosed in the claims. Also, matters in the embodiments and specific disclosure matters in the claims denoted by the same names have corresponding relationships with each other. However, the present invention is not limited to the embodiments, and various modifications of the embodiments may be embodied within the scope of the present invention without departing from the spirit of the invention.

The processing sequence described in the above-described embodiment may be processed as a method having a series of sequences, or may be processed as a computer program for causing a computer to execute a series of sequences and a recording medium storing the computer program. As the recording medium, a hard Disk, a CD (Compact Disc), an MD (MiniDisc), a DVD (digital versatile Disc), a memory card, and a blu-ray Disc (registered trademark) can be used.

Further, the effects described in the present invention are not restrictive but merely exemplary, and other effects may exist.

Further, the present invention may be configured as follows.

(1) A semiconductor device, comprising:

a first semiconductor chip including a first bonding surface including

A first insulating layer, a second insulating layer,

a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and

a first metal layer in a line shape, the first metal layer being arranged outside the plurality of first pads; and

a second semiconductor chip including a second bonding surface bonded to the first bonding surface, the second bonding surface including

A second insulating layer is formed on the first insulating layer,

a plurality of second pads which are arranged at positions facing the first pads and to which a second inner layer circuit insulated by the second insulating layer is electrically connected, and

a second metal layer in a line shape, the second metal layer being arranged at a position facing the first metal layer,

wherein widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region from an end of the first semiconductor chip to the first pad.

(2) The semiconductor device according to (1),

wherein widths of the first metal layer and the second metal layer are widths based on an average of a bonding strength between the first insulating layer and the second insulating layer in the region and a bonding strength between the first metal layer and the second metal layer.

(3) The semiconductor device according to (2),

wherein the widths of the first and second metal layers are substantially equal to a width Q satisfying the following relation,

(x×P+y×Q)/R>z

wherein the content of the first and second substances,

z: a bonding strength per unit area between the first semiconductor chip and the second semiconductor chip,

x: a bonding strength per unit area between the first insulating layer and the second insulating layer,

y: a bonding strength per unit area between the first metal layer and the second metal layer,

p: a length of a joint portion of the first insulating layer and the second insulating layer on a path substantially perpendicularly intersecting with an end portion of the first semiconductor chip, and

r: a length between the first pad on the path and an end of the first semiconductor chip.

(4) The semiconductor device according to the above (3),

wherein the path is a path that: which substantially perpendicularly intersects an end portion of the first semiconductor chip and extends from the end portion of the first semiconductor chip and first reaches the first pad.

(5) The semiconductor device according to the above (4),

wherein the path is a path having the longest distance among such paths: substantially perpendicularly intersects an end portion of the first semiconductor chip, and extends from the end portion of the first semiconductor chip and first reaches the first pad.

(6) The semiconductor device according to any one of (1) to (5),

wherein the first bonding surface further includes a first dummy pad not electrically connected to the first inner layer circuit,

the second bonding surface further includes a second dummy pad arranged at a position facing the first dummy pad and not electrically connected to the second inner layer circuit, and

widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip and reaching first the first pad or the first dummy pad.

(7) The semiconductor device according to any one of (1) to (6),

wherein the first metal layer and the second metal layer are divided into a predetermined number of parts.

(8) The semiconductor device according to any one of (1) to (7),

wherein the first semiconductor chip and the second semiconductor chip are configured in a rectangular shape, and

widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in the region for each side of each of the first semiconductor chip and the second semiconductor chip.

(9) An imaging device includes a first semiconductor chip and a second semiconductor chip,

the first semiconductor chip includes a first bonding surface and a first diffusion layer,

the first engagement surface comprises

A first insulating layer, a second insulating layer,

a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and

a first metal layer in a line shape, the first metal layer being arranged outside the plurality of first pads,

the first diffusion layer includes a semiconductor region that is electrically connected to the first inner layer circuit and converts applied light into an electric signal; and is

The second semiconductor chip bonded to the first bonding surface, the second semiconductor chip including a second bonding surface and a second diffusion layer,

the second engagement surface comprises

A second insulating layer is formed on the first insulating layer,

a plurality of second pads which are arranged at positions facing the first pads and to which a second inner layer circuit insulated by the second insulating layer is electrically connected, and

a second metal layer in a line shape, the second metal layer being arranged at a position facing the first metal layer,

the second diffusion layer includes a semiconductor region electrically connected to the second inner layer circuit and processing the electric signal,

wherein widths of the first metal layer and the second metal layer are widths based on a bonding strength between the first insulating layer and the second insulating layer and a bonding strength between the first metal layer and the second metal layer in a region extending from an end of the first semiconductor chip to the first pad.

List of reference numerals

10 semiconductor device

100 first semiconductor chip

101 micro lens

102 color filter

110 first diffusion layer

120 first joint surface

121 first guard ring

124 first bonding pad

125 first dummy pad

129 first insulating layer

131, 231 wiring layer

132, 232 via hole

200 second semiconductor chip

210 second diffusion layer

220 second joint face

221 second guard ring

224 second bonding pad

225 second dummy pad

229 second insulating layer