Imaging element and electronic device

Abstract

The present disclosure relates to an imaging element and an electronic device that make it possible to further improve an imaging property. A well contact electrode for supplying a predetermined potential to a well of a semiconductor substrate is provided on a back surface side serving as a light receiving surface of the semiconductor substrate on which a photoelectric conversion unit is provided for each pixel, and a negative bias electrode for applying a negative bias to a side wall of the pixel is provided in a trench that separates the pixels in the semiconductor substrate. A first connection terminal provided on a front surface of the semiconductor substrate and the well contact electrode are connected by a well contact connection structure, and a second connection terminal provided on a front surface of the semiconductor substrate and the negative bias electrode are connected by a negative bias connection structure. The present technology can be applied, for example, to a back-illuminated CMOS image sensor.

Description

Image sensor and electronic device

[0001] The present disclosure relates to an imaging element and an electronic device, and more particularly to an imaging element and an electronic device that are capable of further improving imaging characteristics.

[0002] Conventionally, imaging elements such as CMOS (Complementary Metal Oxide Semiconductor) image sensors have employed, for example, a configuration in which a contact is provided to fix the potential of a well in a semiconductor substrate to the GND level, or a configuration in which an electrode is embedded in a trench that separates pixels to apply a negative bias.

[0003] For example, Patent Document 1 discloses a back-illuminated solid-state imaging device in which a back-side contact portion is formed that electrically connects a substrate potential wiring formed on the back side, which is the light-receiving surface of the semiconductor substrate, to the semiconductor substrate.

[0004] JP 2011-129633 A

[0005] However, as pixels become smaller, elements such as transistors become smaller, which raises concerns about deterioration in imaging characteristics, such as increased noise, etc. Therefore, a configuration has been considered in which contacts connected to wells are provided on the back side of the semiconductor substrate, and wiring for applying a negative bias is provided, thereby avoiding the need to miniaturize elements such as transistors arranged on the front side of the semiconductor substrate and improving imaging characteristics.

[0006] The present disclosure has been made in consideration of such circumstances, and aims to further improve imaging characteristics.

[0007] An imaging element according to one aspect of the present disclosure includes a semiconductor substrate in which a photoelectric conversion unit is provided for each pixel, a first electrode provided on the back side of the semiconductor substrate, which is the light-receiving surface of the semiconductor substrate, and supplying a predetermined potential to a well of the semiconductor substrate, a second electrode provided in a trench that separates the pixels in the semiconductor substrate, a first connection structure that connects the first electrode to a first connection terminal provided on the surface of the semiconductor substrate, and a second connection structure that connects the second electrode to a second connection terminal provided on the surface of the semiconductor substrate.

[0008] An electronic device according to one aspect of the present disclosure includes an imaging element having a semiconductor substrate on which a photoelectric conversion unit is provided for each pixel, a first electrode provided on the back side of the semiconductor substrate, which is the light-receiving surface of the semiconductor substrate, and supplying a predetermined potential to a well of the semiconductor substrate, a second electrode provided in a trench that separates the pixels in the semiconductor substrate, a first connection structure that connects a first connection terminal provided on the surface of the semiconductor substrate to the first electrode, and a second connection structure that connects a second connection terminal provided on the surface of the semiconductor substrate to the second electrode.

[0009] In one aspect of the present disclosure, a first electrode that supplies a predetermined potential to a well of the semiconductor substrate is provided on the back side, which is the light-receiving surface of the semiconductor substrate on which a photoelectric conversion unit is provided for each pixel, and a second electrode is provided in a trench that separates the pixels in the semiconductor substrate, a first connection structure connects a first connection terminal provided on the surface of the semiconductor substrate to the first electrode, and a second connection structure connects a second connection terminal provided on the surface of the semiconductor substrate to the second electrode.

[0010] 1 is a diagram illustrating a configuration example of a first embodiment of an image sensor to which the present technology is applied. FIG. 1 is a diagram illustrating an example of the arrangement of a negative bias connection structure and a well contact connection structure. FIG. 2 is a diagram illustrating a separation portion that separates through-electrodes in the negative bias connection structure and the well contact connection structure. FIG. 3 is a diagram illustrating an image sensor of a configuration example in which trenches of a predetermined depth are provided between pixels. FIG. 4 is a diagram illustrating another example of the connection configuration of a negative bias connection structure. FIG. 5 is a diagram illustrating a well contact electrode provided with an opening. FIG. 6 is a diagram illustrating a modified example of the well contact connection structure. FIG. 7 is a diagram illustrating a modified example of the negative bias connection structure and the well contact connection structure. FIG. 8 is a diagram illustrating an image sensor configured to use well contact electrodes as light-shielding metal for waveguides. FIG. 9 is a diagram illustrating a cross section showing the arrangement of well contact electrodes and contact portions at the image height center. FIG. 10 is a diagram illustrating the arrangement of well contact electrodes and contact portions at the image height center. FIG. 11 is a diagram illustrating the arrangement of well contact electrodes and contact portions at the image height end. FIG. 12 is a diagram illustrating a modified example of well contact electrodes at the image height end. FIG. 13 is a diagram illustrating a first variation for strengthening contact. FIG. 14 is a diagram illustrating a second variation for strengthening contact. FIG. 15 is a diagram illustrating a wall structure provided in a filter layer. FIG. 16 is a diagram illustrating variations of well contact electrodes. FIG. 10 is a diagram for explaining a configuration example in which the size of a contact portion is changed according to image height; FIG. 11 is a diagram for explaining a configuration example in which the width of a well contact electrode is changed according to image height; FIG. 12 is a diagram for explaining a layout example of an on-chip lens; FIG. 13 is a diagram for explaining a configuration example in which the size of a contact portion is changed according to image height; FIG. 14 is a diagram for explaining a configuration example in which a well contact electrode is changed according to image height; FIG. 15 is a diagram for explaining a layout example in which an image sensor is used; FIG. 16 is a diagram for explaining a layout example in which an image sensor is used;

[0011] Hereinafter, specific embodiments to which the present technology is applied will be described in detail with reference to the drawings.

[0012] <First Configuration Example of Image Sensor> A configuration example of a first embodiment of an image sensor to which the present technology is applied will be described with reference to FIGS. 1 to 9 .

[0013] FIG. 1 is a diagram showing a configuration example of a first embodiment of an imaging element to which the present technology is applied.

[0014] FIG. 1A shows a cross-sectional example of the configuration near the end of the image sensor 11, and FIG. 1B shows a planar example of the configuration near the end of the image sensor 11.

[0015] The imaging element 11 is provided with a negative bias connection terminal 23 used for connection to a negative bias power supply and a GND connection terminal 24 used for connection to a ground potential via an insulating film 22 laminated on the surface (the surface facing downwards at A in Figure 1) of a semiconductor substrate 21 on which a photoelectric conversion unit is provided for each pixel 12.

[0016] The imaging element 11 is provided with a well contact electrode 26 used for connecting the back surface of the semiconductor substrate 21 to a well via an insulating film 25 laminated on the back surface (the surface facing upward in the direction of A in FIG. 1 ) of the semiconductor substrate 21, which serves as a light-receiving surface that receives light incident on the pixels 12. The well contact electrode 26 is connected to a connection region 28 (e.g., a region with a high concentration of N+ or P+ impurities) provided on the back surface of the semiconductor substrate 21 via a contact portion 27 provided for each pixel 12, via the insulating film 25.

[0017] In the imaging element 11, negative bias electrodes 30 used to apply a negative bias to the side walls of the pixels 12 are provided via an insulating film 29 inside trenches formed as pixel separation sections for separating the semiconductor substrate 21 for each pixel 12. Of the negative bias electrodes 30, negative bias electrodes 30a provided on the outermost side of the imaging element 11 are formed so as to protrude from the rear surface of the semiconductor substrate 21, and connection sections 31 are provided so as to extend from the protruding section toward the outside of the imaging element 11.

[0018] The imaging element 11 is provided with a negative bias connection structure 41 for connecting the negative bias connection terminal 23 on the front side of the semiconductor substrate 21 with the negative bias electrode 30 on the back side of the semiconductor substrate 21. The negative bias connection structure 41 is composed of a through electrode 42, one end of which is connected to the negative bias connection terminal 23 and which is provided to penetrate the semiconductor substrate 21, and a connection portion 43 which is connected to the other end of the through electrode 42 on the back side of the semiconductor substrate 21. In addition, an insulating film 44 is provided in the through hole in which the through electrode 42 is provided, providing insulation between the through electrode 42 and the semiconductor substrate 21.

[0019] 1B, the plurality of connection portions 31 provided so as to extend from the negative bias electrode 30 toward the outside of the imaging element 11 and the plurality of connection portions 43 provided so as to extend from the through electrode 42 toward the inside of the imaging element 11 are arranged at the same pitch and at the same positions along the sides of the imaging element 11. Therefore, the negative bias electrode 30 is electrically connected to the negative bias connection terminal 23 via the negative bias connection structure 41 by a connection configuration in which the respective connection portions 31 and connection portions 43 are connected in planar fashion at the overlapping portions (connection points) of each other.

[0020] In the configuration example shown in Figure 1, the connection parts 31 and the negative bias connection structures 41 are provided at the same pitch as the pitch of the pixels 12, as shown in B of Figure 1, but the connection parts 31 and the negative bias connection structures 41 may be provided at a pitch different from the pitch of the pixels 12.

[0021] The imaging element 11 is provided with a well contact connection structure 51 for connecting a GND connection terminal 24 on the front side of the semiconductor substrate 21 with a well contact electrode 26 on the back side of the semiconductor substrate 21. The well contact connection structure 51 is composed of a through electrode 52 having one end connected to the GND connection terminal 24 and provided to penetrate the semiconductor substrate 21, a connection portion 53 connected to the other end of the through electrode 52 on the back side of the semiconductor substrate 21, a light-shielding film 54 connected to the well contact electrode 26, and a connection portion 55 connecting the connection portion 53 and the light-shielding film 54. The light-shielding film 54 is used to block light from entering pixels 12 in an OPB (Opitical Black) region provided around the sensor surface of the imaging element 11.

[0022] 1B , the plurality of through electrodes 52 are alternately arranged with respect to the plurality of through electrodes 42 at the same pitch as the plurality of through electrodes 42 along the sides of the imaging element 11, and the connection portions 53 connected to the through electrodes 52 are provided so as to extend continuously along the sides of the imaging element 11. The plurality of linking portions 55 are provided so as to connect the connection portions 53 to the light-shielding film 54, passing between the connection points between the plurality of connection portions 31 and the connection portions 43, respectively. Therefore, the well contact connection structure 51 is configured to form a plurality of openings surrounded by the connection portions 53, the light-shielding film 54, and the linking portions 55, and a connection point between the connection portions 31 and the connection portions 43 is provided in each opening. This allows the negative bias power supply and the ground potential to be supplied by the mutually independent electrical systems of the negative bias connection structure 41 and the well contact connection structure 51, respectively.

[0023] The imaging element 11 configured in this manner has the well contact electrode 26 and the negative bias electrode 30 provided so as to be connected from the back surface side of the semiconductor substrate 21, and is capable of supplying a ground potential to the well contact electrode 26 via the well contact connection structure 51 and supplying a negative bias power supply to the negative bias electrode 30 via the negative bias connection structure 41. Therefore, even if the pixels 12 are miniaturized, the imaging element 11 can avoid miniaturizing elements such as transistors on the front surface side of the semiconductor substrate 21.

[0024] That is, in the image sensor 11, since the connection structures for the well contact electrode 26 and the negative bias electrode 30 are not provided on the surface of the semiconductor substrate 21, a larger area can be secured on the surface of the semiconductor substrate 21 for arranging elements such as transistors, thereby improving the degree of layout freedom. As a result, the image sensor 11 can avoid the deterioration of noise that accompanies the miniaturization of elements such as transistors. Furthermore, the image sensor 11 can eliminate the trade-off between dark current and signal charge amount Qs by applying a negative bias from the sidewall of the pixel 12 using the negative bias electrode 30.

[0025] In this way, the imaging device 11 can further improve imaging characteristics by configuring both the well contact electrode 26 and the negative bias electrode 30 to be connected from the back surface side of the semiconductor substrate 21. Furthermore, by using a transparent electrode as the well contact electrode 26, the imaging device 11 can avoid any influence on optical characteristics such as quantum efficiency Qe.

[0026] As shown in Fig. 2, the peripheral regions of the four sides of the imaging element 11 are covered with a light-shielding film 54, and the regions where the light-shielding film 54 is not provided are effective pixel regions where imaging by the pixels 12 is effective. The imaging element 11 may be configured such that the negative bias connection structure 41 and the well contact connection structure 51 are arranged on only one side of the imaging element 11, as shown in Fig. 2A, or may be configured such that the negative bias connection structure 41 and the well contact connection structure 51 are arranged on all four sides of the imaging element 11, as shown in Fig. 2B. Note that, from the viewpoints of IR drop, symmetry, and the like, it is preferable that the imaging element 11 be configured such that the negative bias connection structure 41 and the well contact connection structure 51 are arranged on all four sides of the imaging element 11.

[0027] Alternatively, the imaging element 11 may be configured such that the negative bias connection structure 41 and the well contact connection structure 51 are both disposed to face the upper and lower sides (or the left and right sides) of the imaging element 11, for example.

[0028] 3 , the imaging element 11 can be provided with a trench 61 filled with an insulator as a separation portion that separates the through electrode 42 of the negative bias connection structure 41 from the through electrode 52 of the well contact connection structure 51. In the example shown in the figure, the trench 61, which is formed in a U-shape when the imaging element 11 is viewed from above, is provided so as to surround the through electrode 42.

[0029] By providing such trenches 61, it is possible to more reliably suppress, for example, leakage between the negative bias connection structure 41 and the well contact connection structure 51 caused by process damage. Furthermore, a plurality of trenches 61 may be provided so as to overlap between the through electrode 42 of the negative bias connection structure 41 and the through electrode 52 of the well contact connection structure 51.

[0030] 4, the imaging element 11 may have a configuration in which an insulating film 29 and a negative bias electrode 30 are provided inside a trench formed to a predetermined depth from the rear surface of the semiconductor substrate 21. In other words, the imaging element 11 is not limited to the configuration in which an insulating film 29 and a negative bias electrode 30 are provided inside a trench formed to penetrate the semiconductor substrate 21, as shown in A of FIG.

[0031] 5, the image sensor 11 may be formed so that the tip surface of the negative bias electrode 30b provided on the outermost side of the image sensor 11 is exposed to the insulating film 25, and a connection configuration may be adopted in which the connection portion 43 of the negative bias connection structure 41 is directly connected to the tip surface of the negative bias electrode 30b. In other words, the image sensor 11 is not limited to the connection configuration in which the connection portion 43 is connected in a planar manner to the connection portion 31 provided so as to extend from the negative bias electrode 30a toward the outside of the image sensor 11, as shown in A of FIG.

[0032] For example, polysilicon or metals such as titanium nitride and tungsten can be used as the electrode material of the well contact electrode 26 and the negative bias electrode 30. The well contact electrode 26 and the negative bias electrode 30 may be made of the same electrode material or different electrode materials.

[0033] For example, a decrease in quantum efficiency Qe can be avoided when a transparent electrode material such as InO, InSnO, or ITO is used for the well contact electrode 26. In this case, the well contact electrode 26 can be provided on the back surface of the semiconductor substrate 21 so as to cover the entire surface of the pixel 12 (i.e., without providing an opening), as shown in FIG.

[0034] On the other hand, when a metal-based electrode material is used for the well contact electrode 26, as shown in FIG. 6, the well contact electrode 26 is provided with an opening for receiving light irradiated onto the pixel 12 so as not to affect the optical characteristics of the pixel 12.

[0035] 6A, the trench in which the negative bias electrode 30 is provided is shown by a broken line, and a well contact electrode 26a formed to be wider than the trench is shown along the trench. When the well contact electrode 26a is used, an opening 71a having an area smaller than that of the pixel 12 is provided for each pixel 12.

[0036] Furthermore, when the well contact electrode 26a is used, the well contact electrode 26a overlaps with the pixel 12 on the four sides of the pixel 12 by an amount that is wider than the trench. Therefore, the contact portion 27 can be disposed in the region along the four sides of the pixel 12 where the pixel 12 and the well contact electrode 26a overlap, and the well contact electrode 26a can be connected to the semiconductor substrate 21 via the contact portion 27.

[0037] 6B shows, by a broken line, a trench in which the negative bias electrode 30 is provided, and shows a well contact electrode 26b formed along the trench with substantially the same width as the trench and provided with convex portions that convex toward the pixel 12 at the four corners of the pixel 12. When the well contact electrode 26b is used, an opening 71b having substantially the same area as the pixel 12 is provided for each pixel 12.

[0038] Furthermore, when the well contact electrode 26b is used, the well contact electrode 26b overlaps the pixel 12 at the convex portions of the well contact electrode 26b provided at the four corners of the pixel 12. Therefore, contact portions 27 can be disposed at the four corners of the pixel 12 where the pixel 12 and the well contact electrode 26b overlap, and the well contact electrode 26b can be connected to the semiconductor substrate 21 via the contact portions 27.

[0039] FIG. 7 is a diagram illustrating a modified example of the well contact connection structure 51. In FIG.

[0040] 1 , the well contact connection structure 51 is configured such that the connection portion 53 extends continuously along the side of the image sensor 11. In contrast to this, as shown in FIG. 7 , the well contact connection structure 51A may be configured such that the connection portion 53A is provided discontinuously for each through electrode 52. That is, the well contact connection structure 51A is configured such that the connection portion 53A connected to a certain through electrode 52 is not connected to the connection portion 53A connected to the through electrode 52 adjacent to that through electrode 52.

[0041] FIG. 8 is a diagram illustrating a modification of the negative bias connection structure 41 and the well contact connection structure 51. In FIG.

[0042] 1, the negative bias connection structure 41 and the well contact connection structure 51 are configured so that the through electrodes 52 are disposed outside the imaging element 11 relative to the through electrodes 42 (i.e., the through electrodes 42 are disposed inside the imaging element 11 relative to the through electrodes 52). In contrast to this, as shown in FIG. 8, the negative bias connection structure 41B and the well contact connection structure 51B may be configured so that a connection portion 53B is provided so as to be discontinuous for each through electrode 52B, and the through electrodes 52B are disposed inside the imaging element 11 relative to the through electrodes 42B (i.e., the through electrodes 42B are disposed outside the imaging element 11 relative to the through electrodes 52B).

[0043] FIG. 9 is a diagram illustrating an image sensor 11 having a configuration in which a well contact electrode 26c is used as a light-shielding metal for the waveguide.

[0044] The image sensor 11 is configured such that a filter layer 81 is laminated on the rear surface, which is the light-receiving surface of the semiconductor substrate 21, and an on-chip lens 82 is laminated on the filter layer 81 for each pixel 12. In the filter layer 81, a waveguide 84 that guides light is provided between color filters 83 provided for each pixel 12, and a well contact electrode 26c is used as a light-shielding metal for the waveguide 84.

[0045] 9, the well contact electrode 26c is formed wider than the trench in which the negative bias electrode 30 is provided, the well contact electrode 26 is provided on the filter layer 81 closest to the semiconductor substrate 21, and no insulating film is provided between the filter layer 81 and the semiconductor substrate 21. This results in a connection configuration in which the well contact electrode 26 is directly connected to the connection region 28 of the semiconductor substrate 21. Note that in order to directly connect the well contact electrode 26 to the connection region 28 of the semiconductor substrate 21, it is sufficient that the width of the well contact electrode 26 is at least partially wider than the width of the trench.

[0046] <Second Configuration Example of Image Sensor> A configuration example of a second embodiment of an image sensor to which the present technology is applied will be described with reference to Figs. 10 to 20 .

[0047] 10 , of the four regions divided by horizontal and vertical lines passing through the center point of the sensor surface of the image sensor 11, the upper right region is designated as quadrant 1, the upper left region is designated as quadrant 2, the lower left region is designated as quadrant 3, and the lower right region is designated as quadrant 4. Furthermore, the region that includes the center of the sensor surface of the image sensor 11 and has a low image height is referred to as the image height center, and the region near the end away from the center and has a high image height is referred to as the image height end.

[0048] In the following description, as shown in FIG. 11, a cross section showing the arrangement of the well contact electrodes 26 provided in the insulating film 25 in a planar cross section will be referred to as the A-A cross section, and a cross section showing the arrangement of the contact portions 27 provided in the insulating film 25 in a planar cross section will be referred to as the B-B cross section.

[0049] FIG. 12A shows the AA cross section at the center of the image height, and FIG. 12B shows the BB cross section at the center of the image height.

[0050] 12A, the well contact electrode 26 has substantially the same width as the trench in which the negative bias electrode 30 is provided, and is formed with convex portions that are convex toward the pixel 12 at the four corners of the pixel 12. Then, at the center of the image height, the well contact electrode 26 is disposed so as to overlap with the trench in which the negative bias electrode 30 is provided.

[0051] 12B, trenches in which negative bias electrodes 30 are provided are indicated by dashed lines, and the rectangles enclosed by the trenches are pixels 12. As shown in the figure, contact portions 27 are disposed at one of the four corners of the pixel 12, the corner being farthest from the center point of the sensor surface of the imaging element 11. Therefore, in pixels 12 in the first quadrant, contact portions 27 are disposed at the upper right corner, in pixels 12 in the second quadrant, contact portions 27 are disposed at the upper left corner, in pixels 12 in the third quadrant, contact portions 27 are disposed at the lower left corner, and in pixels 12 in the fourth quadrant, contact portions 27 are disposed at the lower right corner.

[0052] In this way, the contact portion 27 is arranged at the corner of the pixel 12 so as to be symmetrical with respect to a horizontal line passing through the center point of the sensor surface of the image sensor 11 and so as to be symmetrical with respect to a vertical line passing through the center point of the sensor surface of the image sensor 11. In other words, the corner of the pixel 12 where the contact portion 27 is arranged is rotationally symmetrical by 90 degrees in four quadrants centered on the center point of the sensor surface of the image sensor 11.

[0053] Fig. 13B shows the A-A cross section at the image height end, and Fig. 13B shows the B-B cross section at the image height end. Note that Fig. 13 shows the image height end in the first quadrant of the sensor surface of the image sensor 11.

[0054] 13A, the trench in which the negative bias electrode 30 is provided is indicated by a dashed line, and as shown in the figure, at the image height end portion, the well contact electrode 26 is disposed at a position offset with respect to the trench in a direction toward the center point of the sensor surface of the image sensor 11. Therefore, the well contact electrode 26 provided in the first quadrant is disposed at a position offset with respect to the trench in a direction toward the lower left where the center point of the sensor surface of the image sensor 11 is located. For example, this offset amount is set to increase as the image height increases, that is, to increase as the distance from the center point of the sensor surface of the image sensor 11 increases.

[0055] 13B, the trench in which the negative bias electrode 30 is provided is indicated by a dashed line, and the rectangle surrounded by the trench is the pixel 12. As shown in the figure, at the image height end in the first quadrant, the contact portion 27 is disposed in the upper right corner of the pixel 12.

[0056] FIG. 14 shows a modification of the well contact electrode 26 shown in FIG.

[0057] The well contact electrode 26 shown in A of Figure 14 is formed so that the position of the convex portion relative to the trench, which is located at the intersection of the vertical portion extending vertically and the horizontal portion extending horizontally, is the same as the position of the convex portion relative to the trench at the center of the image height, but the vertical portion and the horizontal portion are positioned at a position shifted relative to the trench in the direction toward the center point of the sensor surface of the image sensor 11.

[0058] In this way, the image sensor 11 can accommodate pupil correction by arranging the contact portion 27 provided for each pixel 12 at one corner far from the center point of the sensor surface of the image sensor 11, and arranging the well contact electrode 26 at a position shifted in a direction toward the center point of the sensor surface of the image sensor 11 by an amount of shift corresponding to the image height. This makes it possible to suppress deterioration of optical characteristics when performing pupil correction, which is necessary at the image height end portions where the image height is high.

[0059] In other words, by arranging the contact portion 27 provided for each pixel 12 in one corner far from the center point of the sensor surface, the image sensor 11 can connect the well contact electrode 26 to the semiconductor substrate 21 via the contact portion 27 even if the well contact electrode 26 is arranged at a position shifted toward the center point of the sensor surface depending on the image height. Therefore, when pupil correction is performed, the arrangement of the well contact electrode 26 can be adjusted so that light absorption is reduced depending on the image height. Furthermore, by arranging the contact portion 27 in this manner, the image sensor 11 can perform pupil correction continuously from the center of the image height, avoiding sudden structural changes and achieving a configuration that does not cause steps in image quality.

[0060] FIG. 15 shows a first variation for strengthening the contact.

[0061] For example, by providing a plurality of contact portions 27 for one pixel 12, it is possible to strengthen the contact between the well contact electrode 26 and the semiconductor substrate 21. In the example shown in Fig. 15B, three contact portions 27 are provided for one pixel 12. In this way, along with providing three contact portions 27, convex portions that overlap the three contact portions 27 are formed on the well contact electrode 26, as shown in Fig. 15A.

[0062] FIG. 16 shows a second variation for strengthening the contact.

[0063] In the example shown in Fig. 16B, one L-shaped contact portion 27 is provided in which the three contact portions 27 shown in Fig. 15B are connected. In this way, along with providing the L-shaped contact portion 27, a convex portion overlapping the L-shaped contact portion 27 is formed on the well contact electrode 26 as shown in Fig. 16A.

[0064] As explained with reference to Figures 15 and 16, by increasing the connection area between the semiconductor substrate 21 and the well contact electrode 26 via the contact portion 27, the resistance to the semiconductor substrate 21 can be reduced, and as a result, the IR drop can be reduced.

[0065] The wall structure provided in the filter layer 81 will be described with reference to FIG.

[0066] 17A, the image sensor 11 is configured such that filter walls 91 having a light-blocking property for preventing color mixing in the filter layer 81 are provided between the pixels 12 in the filter layer 81 and connected to the well contact electrodes 26. The filter walls 91 are formed using a metal material with high conductivity such as tungsten, and the well contact electrodes 26 are formed using a metal material with low light absorption such as titanium nitride.

[0067] As shown in the figure, the well contact electrode 26 and the filter wall 91 are connected, and the combination of these two types of metal materials makes it possible to prevent IR drop while suppressing light absorption, and also to form an electrode structure that supplies ground potential to the well from the back side of the semiconductor substrate 21.

[0068] 17B, ​​the image sensor 11 may be configured such that low refractive index regions 92 that reflect obliquely incident light are provided between the pixels 12 in the filter layer 81, and filter walls 91 are provided on the insulating film 25 side of the low refractive index regions 92. For example, an air layer can be used as the low refractive index region 92. The metal material used for the filter walls 91 can be the same as that used in conventional image sensors.

[0069] In this way, by combining two types of metal materials, it is possible to configure an electrode structure in which the well contact electrode 26 and the filter wall 91 are connected, and which supplies a ground potential to the well from the back surface side of the semiconductor substrate 21. Furthermore, by providing the filter layer 81 with a wall structure consisting of the filter wall 91 and the low refractive index region 92, it is possible to improve the quantum efficiency Qe.

[0070] With reference to FIG. 18, variations of well contact electrode 26 will be described.

[0071] 18A, the tip of the negative bias electrode 30 is recessed from the rear surface of the semiconductor substrate 21, and the well contact electrode 26 is directly connected to the rear surface of the semiconductor substrate 21. That is, in this variation, the semiconductor substrate 21 and the well contact electrode 26 can be connected over a wider area without providing the contact portion 27. By adopting such a variation, the IR drop can be reduced by the amount that the connection does not go through the contact portion 27.

[0072] 18B, the tip of the negative bias electrode 30 is recessed from the back surface of the semiconductor substrate 21, and the well contact electrode 26 is disposed on the back surface side of the semiconductor substrate 21 inside the trench in which the negative bias electrode 30 is provided, and the well contact electrode 26 is connected to the side surface of the trench. By employing such a variation, it is possible to reduce light absorption by the well contact electrode 26.

[0073] 18C, a well contact electrode 26 is provided in an insulating film 25, and the well contact electrode 26 and the semiconductor substrate 21 are connected via a contact portion 27, and the well contact electrode 26 and the negative bias electrode 30 are connected via a contact portion 93. In this variation, the negative bias electrode 30 is not used as an electrode for applying a negative bias to the sidewall of the pixel 12, but is used as an electrode for supplying a ground potential to the well contact electrode 26. By employing such a variation, the number of steps required for supplying a ground potential to the well contact electrode 26 can be reduced.

[0074] An example of a configuration in which the size of the contact portion 27 is changed depending on the image height will be described with reference to FIG.

[0075] FIG. 19A shows a cross section taken along line BB at the center of the image height, and FIG. 19B shows a cross section taken along line BB at the edge of the image height.

[0076] For example, the contact portion 27 can be formed so that its size decreases as the image height increases. That is, the contact portion 27 is formed so that its size at the image height end portion is smaller as shown in B of Fig. 19 than at the image height center portion as shown in A of Fig. 19 .

[0077] In this way, by changing the size of the contact portion 27 depending on the image height, it is possible to correct the oblique incidence and color mixing depending on the image height, thereby suppressing shading.

[0078] An example of a configuration in which the width of the well contact electrode 26 is changed depending on the image height will be described with reference to FIG.

[0079] FIG. 20A shows the AA cross section at the center of the image height, and FIG. 20B shows the AA cross section at the edge of the image height.

[0080] For example, the well contact electrode 26 can be formed so that its width narrows as the image height increases. That is, the well contact electrode 26 is formed so that the width of the well contact electrode 26 at the image height end portion is narrower as shown in B of Fig. 20 than the width of the well contact electrode 26 at the image height center portion as shown in A of Fig. 20.

[0081] In this way, by changing the width of the well contact electrode 26 depending on the image height, it is possible to correct the oblique incidence and color mixing depending on the image height, thereby suppressing shading.

[0082] <Variations in Combinations of On-Chip Lenses, Trench, and Contact Portions> With reference to FIGS. 21 to 23 , variations in combinations of the layout of the on-chip lenses 82 with the structure of the trench in which the negative bias electrode 30 is provided and the arrangement structure including the arrangement of the contact portions 27 will be described.

[0083] FIG. 21 is a diagram showing an example of the layout of the on-chip lens 82. As shown in FIG.

[0084] A in FIG. 21 shows a first layout example in which a red pixel 12R and a blue pixel 12B are arranged diagonally, and a green pixel 12Gr and a green pixel 12Gb are arranged diagonally in a 2×2 pixel array (a so-called Bayer array), and one on-chip lens 82 is arranged for each pixel 12.

[0085] FIG. 21B shows a second layout example in which four red pixels 12R arranged in a 2×2 array and four blue pixels 12B arranged in a 2×2 array are diagonally arranged, and four green pixels 12Gr arranged in a 2×2 array and four green pixels 12Gb arranged in a 2×2 array are diagonally arranged, in a 4×4 pixel array, and one on-chip lens 82 is arranged for each pixel 12.

[0086] FIG. 21C shows a third layout example in which, in a 4×4 pixel array in which four red pixels 12R arranged in a 2×2 array and four blue pixels 12B arranged in a 2×2 array are diagonally arranged, and four green pixels 12Gr arranged in a 2×2 array and four green pixels 12Gb arranged in a 2×2 array are diagonally arranged, one on-chip lens 82 is arranged for each of the four pixels 12 of the same color arranged in a 2×2 array.

[0087] 22 , an example of an arrangement structure including the structure of the trench in which the negative bias electrode 30 is provided and the arrangement of the contact portion 27 will be described. Note that Fig. 22 shows the arrangement of the contact portion 27 at the image height end portion in the first quadrant of the sensor surface of the image sensor 11.

[0088] 22A shows a first arrangement structure example, which is composed of a trench structure in which a negative bias electrode 30 is provided between each of four pixels 12 arranged in a 2×2 matrix, and an arrangement of contact portions 27 provided in the upper right corners of the four pixels 12. For example, the first arrangement structure example can be used in combination with the first layout example of the on-chip lens 82 shown in FIG. 21A or the second layout example of the on-chip lens 82 shown in FIG. 21B.

[0089] 22B shows a second arrangement structure example including a trench structure in which negative bias electrodes 30 are provided between adjacent pixels 12 and extending a predetermined length from approximately the center of two opposing sides of each pixel 12 toward the inside of the pixel 12, for four pixels 12 arranged in a 2 × 2 matrix, and an arrangement of contact portions 27 provided at the upper right corners of the four pixels 12. For example, the second arrangement structure example can be used in combination with the first layout example of the on-chip lenses 82 shown in FIG. 21A or the second layout example of the on-chip lenses 82 shown in FIG. 21B.

[0090] 22C shows a third example of an arrangement structure, which includes a trench structure in which a negative bias electrode 30 is provided between each of the four pixels 12 arranged in a 2×2 matrix, and an arrangement of contact portions 27 provided at the upper right corners of the three pixels 12 at the upper right, upper left, and lower right. For example, the third example of an arrangement structure can be used in combination with the third example of the layout of the on-chip lens 82 shown in FIG. 21C.

[0091] 22D shows a fourth arrangement structure example in which, for four pixels 12 arranged in a 2×2 matrix, no trench in which a negative bias electrode 30 is provided is provided at the center of the four pixels 12, and the semiconductor substrate 21 is connected at the center, and the contact portion 27 is provided at the upper right corner of the upper right pixel 12. For example, the fourth arrangement structure example can be used in combination with the second layout example of the on-chip lens 82 shown in FIG. 21B.

[0092] FIG. 23 is a diagram showing an example of well contact electrodes 26 arranged in a third arrangement structure example as shown in FIG. 22C. As described above, the third arrangement structure example is used in combination with the third layout example of on-chip lenses 82 shown in FIG. 21C. That is, in the 4×4 pixel array shown in the figure, one on-chip lens 82 is arranged for the four pixels 12 (red pixels 12R) arranged in a 2×2 matrix at the top right, one on-chip lens 82 is arranged for the four pixels 12 (green pixels 12Gr) arranged in a 2×2 matrix at the top left, one on-chip lens 82 is arranged for the four pixels 12 (green pixels 12Gb) arranged in a 2×2 matrix at the bottom right, and one on-chip lens 82 is arranged for the four pixels 12 (blue pixels 12B) arranged in a 2×2 matrix at the bottom left. Note that FIG. 23 shows the arrangement of contact portions 27 at the image height end of the first quadrant of the sensor surface of the image sensor 11.

[0093] 23 , of four pixels 12 of the same color arranged in a 2×2 matrix, contact portions 27 are provided in the upper right corners of three pixels 12: the upper right, upper left, and lower right. The well contact electrodes 26 are provided along the right sides of the pixels 12 where the contact portions 27 are provided consecutively for each pixel 12 in the vertical direction, and along the top sides of the pixels 12 where the contact portions 27 are provided consecutively for each pixel 12 in the horizontal direction. In other words, openings of the well contact electrodes 26 are provided for each of the four pixels 12 of the same color arranged in a 2×2 matrix, and the well contact electrodes 26 are provided along the right sides and top sides of each of the four pixels 12 of the same color.

[0094] <Configuration Example of Electronic Device> The imaging element 11 as described above can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, or other devices with imaging functions.

[0095] FIG. 24 is a block diagram showing an example of the configuration of an imaging device mounted on an electronic device.

[0096] As shown in FIG. 24, the imaging device 101 comprises an optical system 102, an imaging element 103, a signal processing circuit 104, a monitor 105, and a memory 106, and is capable of capturing still images and moving images.

[0097] The optical system 102 is configured to have one or more lenses, and guides image light (incident light) from a subject to the image sensor 103 , forming an image on the light receiving surface (sensor section) of the image sensor 103 .

[0098] The image sensor 103 is the image sensor 11 described above. Electrons are accumulated in the image sensor 103 for a certain period of time in accordance with an image formed on the light receiving surface via the optical system 102. A signal corresponding to the electrons accumulated in the image sensor 103 is then supplied to the signal processing circuit 104.

[0099] The signal processing circuit 104 performs various types of signal processing on the pixel signals output from the image sensor 103. The image (image data) obtained by the signal processing performed by the signal processing circuit 104 is supplied to a monitor 105 for display, or supplied to a memory 106 for storage (recording).

[0100] In the imaging device 101 configured in this manner, by applying the imaging element 11 described above, it is possible to capture images with higher image quality, for example.

[0101] <Example of Use of Image Sensor> FIG. 25 is a diagram showing an example of use of the image sensor (imaging element) described above.

[0102] The image sensor described above can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-rays, for example, as follows.

[0103] ・Devices for taking images for viewing purposes, such as digital cameras and mobile devices with camera functions. ・Devices for traffic purposes, such as in-vehicle sensors that take images of the front, rear, surroundings, and interior of a car for safe driving such as automatic stopping, and for recognizing the driver's state, surveillance cameras that monitor moving vehicles and roads, and distance measuring sensors that measure distances between vehicles. ・Devices for home appliances such as TVs, refrigerators, and air conditioners that take images of user gestures and operate the device according to those gestures. ・Devices for medical and healthcare purposes, such as endoscopes and devices that take images of blood vessels by receiving infrared light. ・Devices for security purposes, such as surveillance cameras for crime prevention and cameras for person authentication. ・Devices for beauty purposes, such as skin measuring devices that take images of the skin and microscopes that take images of the scalp. ・Devices for sports purposes, such as action cameras and wearable cameras for sports, etc. ・Devices for agricultural purposes, such as cameras to monitor the condition of fields and crops.

[0104] <Examples of Combinations of Configurations> The present technology may also be configured as follows: (1) An imaging element including: a semiconductor substrate in which a photoelectric conversion unit is provided for each pixel; a first electrode provided on a back surface side that serves as a light-receiving surface of the semiconductor substrate and that supplies a predetermined potential to a well of the semiconductor substrate; a second electrode provided in a trench that separates the pixels from each other in the semiconductor substrate; a first connection structure that connects a first connection terminal provided on a surface of the semiconductor substrate to the first electrode; and a second connection structure that connects a second connection terminal provided on the surface of the semiconductor substrate to the second electrode. (2) The imaging element described in (1) above, wherein the first connection structure is configured to include a first through electrode having one end connected to the first connection terminal and provided through the semiconductor substrate, a first connection portion connected to the other end of the first through electrode on the back surface side of the semiconductor substrate, a light-shielding film connected to the first electrode and shading an OPB (Opitical Black) region, and a connection portion connecting the first connection portion and the light-shielding film; and the second connection structure is configured to include a second through electrode having one end connected to the second connection terminal and provided through the semiconductor substrate, and a second connection portion connected to the other end of the first through electrode on the back surface side of the semiconductor substrate and connected to the second electrode. (3) The imaging element according to (2) above, wherein a plurality of the first through electrodes and a plurality of the second through electrodes are arranged at a predetermined pitch along a side of the imaging element to form the first connection structure and the second connection structure, and the first connection structure and the second connection structure are arranged on all four sides of the peripheral region of the imaging element or on only one side of the peripheral region of the imaging element. (4) The imaging element according to (2) or (3) above, wherein a trench is provided to separate the first through electrodes and the second through electrodes. (5) The imaging element according to any of (1) to (4) above, wherein, when a transparent electrode material is used for the first electrode, the first electrode is provided on the back surface of the semiconductor substrate so as to cover the entire surface of the pixel.(6) The imaging element according to any of (1) to (5) above, wherein, when a metal material is used for the first electrode, the first electrode is formed so as to have an opening on the back surface of the semiconductor substrate for receiving light irradiated onto the pixel. (7) The imaging element according to (6) above, wherein the first electrode is used as a light-shielding metal for a waveguide provided between the pixels in a filter layer stacked on the back surface of the semiconductor substrate. (8) The imaging element according to any of (2) to (7) above, wherein a plurality of the first through-hole electrodes are arranged outside the imaging element with respect to a plurality of the second through-hole electrodes, and the first connection portion connected to the plurality of first through-hole electrodes is provided so as to extend continuously along a side of the imaging element. (9) The imaging element according to any of (2) to (8) above, wherein a plurality of the second through-hole electrodes are arranged outside the imaging element with respect to a plurality of the first through-hole electrodes, and the first connection portion connected to the plurality of first through-hole electrodes is provided for each of the first through-hole electrodes so as to be discontinuous along a side of the imaging element. (10) The image sensor according to any of (1) to (9) above, further comprising a contact portion connecting the first electrode and the semiconductor substrate, wherein the contact portion is arranged at one of the four corners of the pixel that is farthest from a center point of the sensor surface of the image sensor, and the first electrode is arranged at a position shifted in a direction toward the center point of the sensor surface of the image sensor relative to a trench in which the second electrode is provided, according to the image height of the image sensor. (11) The corners of the pixel where the contact portion is arranged are rotationally symmetric by 90 degrees in four quadrants centered on the center point of the sensor surface of the image sensor. The image sensor according to (10) above. (12) The image sensor according to (10) or (11) above, wherein a plurality of the contact portions are provided for one pixel.(13) The image sensor according to any one of (10) to (12) above, further comprising a filter wall having a light-blocking property, the filter wall being provided between the pixels in a filter layer stacked on the back surface of the semiconductor substrate and connected to the first electrode, wherein the first electrode is formed using a metal material with low light absorption, and the filter wall is formed using a metal material with high conductivity. (14) The image sensor according to (13) above, wherein the filter wall is provided inside a low refractive index region provided between the pixels in a filter layer stacked on the back surface of the semiconductor substrate. (15) The image sensor according to any one of (10) to (14) above, wherein the contact portion is formed to have a smaller size as the image height of the image sensor increases. (16) The image sensor according to any one of (10) to (15) above, wherein the first electrode is formed to have a narrower width as the image height of the image sensor increases. (17) The image sensor according to any one of (1) to (16) above, wherein the first electrode is directly connected to the back surface of the semiconductor substrate. (18) The imaging element according to any one of (1) to (16) above, wherein the first electrode is disposed inside a trench in which the second electrode is provided, and is connected to a side surface of the trench. (19) The image sensor according to (10), wherein in a 4x4 pixel array in which four red pixels arranged in a 2x2 matrix and four blue pixels arranged in a 2x2 matrix are diagonally arranged, and four green pixels arranged in a 2x2 matrix and four green pixels arranged in a 2x2 matrix are diagonally arranged, one on-chip lens is arranged for each of the four 2x2 pixels of the same color, and trenches in which the second electrodes are provided are formed between adjacent four 2x2 pixels of the same color, and in a first quadrant of a sensor surface of the image sensor, the contact portions are provided in the upper right corners of three of the four 2x2 pixels of the same color, namely, the upper right, the upper left, and the lower right, among the four 2x2 pixels of the same color, and the first electrodes are provided along the right and upper sides of each of the four 2x2 pixels so that an opening is provided for each of the four 2x2 pixels.(20) An electronic device comprising an imaging element having: a semiconductor substrate on which a photoelectric conversion unit is provided for each pixel; a first electrode provided on the back side of the semiconductor substrate, which is the light-receiving surface of the semiconductor substrate, and supplying a predetermined potential to a well of the semiconductor substrate; a second electrode provided in a trench separating the pixels from each other in the semiconductor substrate; a first connection structure connecting a first connection terminal provided on the surface of the semiconductor substrate to the first electrode; and a second connection structure connecting a second connection terminal provided on the surface of the semiconductor substrate to the second electrode.

[0105] It should be noted that the present embodiment is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0106] REFERENCE SIGNS LIST 11 imaging element, 12 pixel, 21 semiconductor substrate, 22 insulating film, 23 negative bias connection terminal, 24 GND connection terminal, 25 insulating film, 26 well contact electrode, 27 contact portion, 28 connection region, 29 insulating film, 30 negative bias electrode, 31 connection portion, 41 negative bias connection structure, 42 through electrode, 43 connection portion, 44 insulating film, 51 well contact connection structure, 52 through electrode, 53 connection portion, 54 light-shielding film, 55 coupling portion, 61 trench, 71 opening, 81 filter layer, 82 on-chip lens, 83 color filter, 84 waveguide, 91 filter wall, 92 low refractive index region, 93 contact portion

Claims

1. An image sensor comprising: a semiconductor substrate provided with a photoelectric conversion unit for each pixel; a first electrode provided on the back surface side serving as the light receiving surface of the semiconductor substrate for supplying a predetermined potential to the well of the semiconductor substrate; a second electrode provided in a trench for separating the pixels in the semiconductor substrate; a first connection structure for connecting a first connection terminal provided on the surface of the semiconductor substrate and the first electrode; and a second connection structure for connecting a second connection terminal provided on the surface of the semiconductor substrate and the second electrode.

2. The image sensor according to claim 1, wherein the first connection structure includes: a first through electrode having one end connected to the first connection terminal and provided to penetrate the semiconductor substrate; a first connection portion connected to the other end of the first through electrode on the back surface side of the semiconductor substrate; a light shielding film connected to the first electrode and shielding an OPB (Optical Black) region; and a connection portion for connecting the first connection portion and the light shielding film. The second connection structure includes: a second through electrode having one end connected to the second connection terminal and provided to penetrate the semiconductor substrate; and a second connection portion connected to the other end of the first through electrode on the back surface side of the semiconductor substrate and connected to the second electrode.

3. The image sensor according to claim 2, wherein a plurality of the first through electrodes and a plurality of the second through electrodes are arranged at a predetermined pitch along the sides of the image sensor to form the first connection structure and the second connection structure. The first connection structure and the second connection structure are arranged on all four sides of the peripheral region of the image sensor, or are arranged on only one side of the peripheral region of the image sensor.

4. The image sensor according to claim 2, wherein a trench is provided for separating between the first through electrode and the second through electrode.

5. The image sensor according to claim 1, wherein when a transparent electrode material is used as the first electrode, the first electrode is provided to cover the entire surface of the pixel on the back surface of the semiconductor substrate.

6. The image sensor according to claim 1, wherein when a metal material is used as the first electrode, the first electrode is formed such that an opening is provided for receiving light irradiated to the pixel on the back surface of the semiconductor substrate.

7. The image pickup device according to claim 6, wherein the first electrode is used as a light-shielding metal for a waveguide provided between the pixels in a filter layer laminated on the back surface of the semiconductor substrate.

8. The image pickup device according to claim 2, wherein a plurality of the first through electrodes are arranged outside the image pickup device with respect to a plurality of the second through electrodes, and a first connection portion connected to the plurality of the first through electrodes is provided so as to continuously extend along a side of the image pickup device.

9. The image pickup device according to claim 2, wherein a plurality of the second through electrodes are arranged outside the image pickup device with respect to a plurality of the first through electrodes, and a first connection portion connected to the plurality of the first through electrodes is provided for each of the first through electrodes so as to be discontinuous along a side of the image pickup device.

10. The image pickup device according to claim 1, further comprising a contact portion connecting the first electrode and the semiconductor substrate, wherein the contact portion is arranged at one corner far from a center point of a sensor surface of the image pickup device among four corners of the pixel, and the first electrode is arranged at a position shifted according to an image height of the image pickup device in a direction toward the center point of the sensor surface of the image pickup device with respect to a trench where the second electrode is provided.

11. The image pickup device according to claim 10, wherein a corner of the pixel where the contact portion is arranged is rotationally symmetric by 90 degrees in four quadrants centered on a center point of a sensor surface of the image pickup device.

12. The image pickup device according to claim 10, wherein a plurality of the contact portions are provided for one pixel.

13. The image pickup device according to claim 10, further comprising a light-shielding filter wall provided between the pixels in a filter layer laminated on the back surface of the semiconductor substrate and connected to the first electrode, wherein the first electrode is formed using a metal material with low light absorption, and the filter wall is formed using a metal material with high conductivity.

14. The image pickup device according to claim 13, wherein the filter wall is provided inside a low refractive index region provided between the pixels in a filter layer laminated on the back surface of the semiconductor substrate.

15. The image pickup device according to claim 10, wherein the size of the contact portion is formed smaller as the image height of the image pickup device increases.

16. The imaging device according to claim 10, wherein the first electrode is formed with a width that becomes narrower as the image height of the imaging element increases.

17. The imaging device according to claim 1, wherein the first electrode is directly connected to the back surface of the semiconductor substrate.

18. The imaging device according to claim 1, wherein the first electrode is disposed inside a trench in which the second electrode is provided and is connected to the side surface of the trench.

19. In a 4×4 pixel array in which four red pixels arranged in 2×2 and four blue pixels arranged in 2×2 are arranged diagonally, and four green pixels arranged in 2×2 and four green pixels arranged in 2×2 are arranged diagonally, an on-chip lens is arranged one by one for four pixels of the same color arranged in 2×2. For four pixels of the same color arranged in 2×2, a trench in which the second electrode is provided is formed between adjacent pixels. In the first quadrant of the sensor surface of the imaging device, among four pixels of the same color arranged in 2×2, a contact portion is provided at the upper right corner of the upper right, upper left, and lower right three pixels. The first electrode is provided along the right side and the upper side of each of the four pixels so that an opening is provided for each of the four pixels arranged in 2×2. The imaging device according to claim 10.

20. An electronic device including an imaging device having a semiconductor substrate provided with a photoelectric conversion unit for each pixel, a first electrode provided on the back surface side serving as a light receiving surface of the semiconductor substrate and supplying a predetermined potential to a well of the semiconductor substrate, a second electrode provided in a trench separating the pixels in the semiconductor substrate, a first connection structure connecting a first connection terminal provided on the surface of the semiconductor substrate and the first electrode, and a second connection structure connecting a second connection terminal provided on the surface of the semiconductor substrate and the second electrode.

Images