JP2023083675A - Solid-state imaging device - Google Patents

Abstract

To provide a solid-state imaging device, capable of suppressing an increase in dark current caused by heat generation in a circuit area.SOLUTION: The present technique provides a solid-state imaging device which includes an optical black pixel area with a first light shielding layer, an effective pixel area, and a circuit area, the first light shielding layer having a first convex structure including a first convex part on a light incident surface side. The effective pixel area has a second light shielding layer that may have a second convex structure including a second convex part on a light incident surface side. The circuit area has a third light shielding layer that may have a third convex structure including a third convex part on a light incident surface side.SELECTED DRAWING: Figure 2

Description

The present technology relates to solid-state imaging devices.

2. Description of the Related Art Conventionally, a solid-state imaging device is used to capture image data in an imaging device or the like. 2. Description of the Related Art It is known that a pixel in a solid-state imaging device generates dark current even when no light is incident thereon. When dark current occurs, noise may occur in image data. Therefore, various techniques have been proposed for removing noise due to dark current. For example, Patent Document 1 below discloses a solid-state imaging device in which a horizontal light-shielding region and a vertical light-shielding region that are light-shielded are arranged around a photosensitive region that is not light-shielded.

JP 2014-207631 A

For example, in a CMOS (Complementary Metal Oxide Semiconductor) type solid-state imaging device, dark current may increase due to heat generated in a logic circuit that performs signal processing being transferred to a pixel region.

Therefore, the main object of the present technology is to provide a solid-state imaging device capable of suppressing an increase in dark current caused by heat generation in a circuit region.

The present technology includes an optical black pixel region having a first light shielding layer, an effective pixel region, and a circuit region, and the first light shielding layer has a first convex structure including a first convex portion on a light incident surface side. to provide a solid-state imaging device.
The effective pixel area may have a second light shielding layer, and the second light shielding layer may have a second convex structure including a second convex portion on the light incident surface side.
The circuit region may have a third light shielding layer, and the third light shielding layer may have a third convex structure including a third convex portion on the light incident surface side.
A plurality of the first protrusions may be arranged in the first protrusion structure.
A plurality of the second protrusions may be arranged in the second protrusion structure.
A said 3rd convex structure WHEREIN: Many said 3rd convex parts may be arrange|positioned.
Said 1st convex structure WHEREIN: A some linear said 1st convex part may be arrange|positioned in parallel.
Said 3rd convex structure WHEREIN: A some linear said 3rd convex part may be arrange|positioned in parallel.
The first convex structure may be made of the same material as the first light shielding layer.
The second convex structure may be made of the same material as the second light shielding layer.
The third convex structure may be made of the same material as the third light shielding layer.
The optical black pixel area may not have an on-chip lens.
The solid-state imaging device may have a connecting portion connecting the semiconductor substrate on which the optical black pixel region is formed and the first light shielding layer.
The solid-state imaging device may have a connecting portion connecting the semiconductor substrate on which the circuit region is formed and the third light shielding layer.
The height of the first protrusion may be 100 nm or more.
The height of the second protrusion may be 100 nm or more.
The height of the third protrusion may be 100 nm or more.

FIG. 1A is a schematic cross-sectional view of part of a conventional solid-state imaging device. FIG. 1B is a schematic plan view of a conventional solid-state imaging device viewed from the light incident surface side. 1 is a schematic cross-sectional view showing part of a solid-state imaging device according to a first embodiment; FIG. It is a typical sectional view showing a part of modification of a solid-state imaging device concerning a 1st embodiment. It is a typical sectional view of the 1st convex structure in a 1st light shielding layer. 5A to 5C are schematic plan views of the light shielding layer of the solid-state imaging device according to the first embodiment, viewed from the light incident surface side. FIG. 6A is a schematic cross-sectional view showing an example of a connecting portion; FIG. 6B is a schematic cross-sectional view showing another example of the communication portion. 2 is a schematic plan view of the solid-state imaging device according to the first embodiment, viewed from the light incident surface side; FIG. 4A and 4B are schematic cross-sectional views showing manufacturing steps of the solid-state imaging device according to the first embodiment; 4A and 4B are schematic cross-sectional views showing manufacturing steps of the solid-state imaging device according to the first embodiment; It is a schematic diagram which shows the laminated structure of the semiconductor substrate in the solid-state imaging device which concerns on 2nd Embodiment. It is a typical sectional view showing a part of solid-state imaging device concerning a 2nd embodiment. It is a figure which shows the usage example of the solid-state imaging device of this technique. It is a functional block diagram showing an example of electronic equipment to which a solid-state imaging device of this art is applied. 1 is a diagram showing an example of a schematic configuration of an endoscopic surgery system; FIG. 3 is a block diagram showing an example of functional configurations of a camera head and a CCU; FIG. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; FIG. FIG. 4 is an explanatory diagram showing an example of installation positions of an outside information detection unit and an imaging unit;

A preferred embodiment for implementing the present technology will be described below. It should be noted that the embodiments described below show typical embodiments of the present technology, and the scope of the present technology is not limited only to these embodiments.

Unless otherwise specified, in this specification, "up" means the upward direction in the drawings, "downward" means the downward direction in the drawings, and "left" means the leftward direction in the drawings. and "right" means to the right in the figures.

The present technology will be described in the following order.
1. Conventional solid-state imaging device2. Solid-state imaging device of the present technology 2-1. First Embodiment 2-2. Second Embodiment 3. Usage example of solid-state imaging device to which this technology is applied 4. Example of application to endoscopic surgery system5. Example of application to mobile objects

1. Conventional solid-state imaging device

A configuration of a conventional solid-state imaging device will be described with reference to FIG. FIG. 1 is a schematic diagram showing a conventional solid-state imaging device 900. As shown in FIG. FIG. 1A is a schematic cross-sectional view of part of a conventional solid-state imaging device 900. FIG. FIG. 1B is a schematic plan view of a conventional solid-state imaging device 900 viewed from the light incident surface side. As an example, a case where the solid-state imaging device 900 is a back-illuminated complementary metal oxide semiconductor (CMOS) solid-state imaging device will be described below. In a back-illuminated CMOS solid-state imaging device, light enters from the back side of a semiconductor substrate on which pixel transistors are formed. In the solid-state imaging device 900 shown in FIG. 1A, the upper side is the light incident surface side (rear side), and the lower side is the surface side (front side) facing the light incident surface.

As shown in FIG. 1A, solid-state imaging device 900 includes pixel region R10. A plurality of pixels PX that generate pixel signals are formed in the pixel region R10. Each pixel PX has a photodiode PD. A photodiode PD is an example of a photoelectric conversion element.

The pixel region R10 includes an optical black pixel region (OPB pixel region) R11 and an effective pixel region R12. An optical black pixel (OPB pixel) P11 is formed in the OPB pixel region R11. Effective pixels P12 are formed in the effective pixel region R12. Thus, the plurality of pixels PX formed in the pixel region R10 include the OPB pixel P11 and the effective pixel P12.

A solid-state imaging device 900 includes a semiconductor substrate 20 . The semiconductor substrate 20 is made of silicon (Si), for example. The thickness of the semiconductor substrate may be, for example, 1 μm to 6 μm.

The semiconductor substrate 20 may have pixel isolation portions 21 between adjacent pixels PX. The pixel separation section 21 has an insulating film. This electrically isolates adjacent pixels PX, that is, adjacent photodiodes PD. When the structure of the semiconductor substrate 20 is seen in a plan view from the light incident surface side as shown in FIG. 1B, the pixel separating portion 21 is formed in a grid pattern so as to separate adjacent pixels PX. A photodiode PD is formed in a region separated by the pixel separation portion 21 .

The semiconductor substrate 20 further comprises a plurality of pixel transistors (not shown). The plurality of pixel transistors may be, for example, four MOS transistors including a transfer transistor, a reset transistor, a select transistor, and an amplifier transistor.

As shown in FIG. 1A, the solid-state imaging device 900 includes a multilayer wiring layer 30 on the front side (lower side) of the semiconductor substrate. The multilayer wiring layer 30 includes, for example, a plurality of conductor layers forming wirings, electrodes, etc., an interlayer insulation layer for insulating between the conductor layers, and contacts for connecting the conductor layers through the interlayer insulation layers. The multilayer wiring layer 30 is appropriately connected to the gate, source, and drain of the pixel transistor provided on the semiconductor substrate 20 .

The solid-state imaging device 900 includes a transparent insulating layer 40 and an on-chip lens 50 in this order on the light incident surface side (upper side) of the semiconductor substrate 20 .

The transparent insulating layer 40 has optical transparency and insulating properties. The transparent insulating layer 40 uses one or more materials selected from, for example, silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon oxynitride (SiON), and hafnium oxide (HfO ₂ ). may be formed by

The on-chip lens 50 can be made of, for example, a resin material such as styrene resin, acrylic resin, styrene-acrylic copolymer resin, and siloxane resin. An on-chip lens 50 collects the incident light. The collected light is efficiently incident on the photodiode PD.

In the solid-state imaging device 900 , the OPB pixel region R11 has a first light shielding layer 910 . The first light shielding layer 910 is provided on the light incident surface side of the transparent insulating layer 40 . The first light shielding layer 910 extends parallel to the transparent insulating layer 40 and is provided to cover the OPB pixel P11. In the OPB pixel P<b>11 , light incident from the back side of the solid-state imaging device 900 is blocked by the first light shielding layer 910 and does not reach the photodiode PD in the semiconductor substrate 20 .

The solid-state imaging device 900 may have, for example, a connecting portion 930 connecting the semiconductor substrate 20 and the first light shielding layer 910 . The contact part 930 may prevent arcing from occurring due to floating of the first light shielding layer 910 in the OPB pixel region R11.

In the solid-state imaging device 900, the effective pixel region R12 has a second light shielding layer 920. As shown in FIG. The second light shielding layer 920 is provided on the light incident surface side of the transparent insulating layer 40 . The second light shielding layer 920 extends parallel to the transparent insulating layer 40 and is provided between adjacent effective pixels P12. When the second light shielding layer 920 is seen in a plan view from the light incident surface side as shown in FIG. 1B, the second light shielding layer 920 is formed in a grid pattern between adjacent effective pixels P11. The second light shielding layer 920 is not provided in the portion corresponding to the photodiode PD on the light incident surface side of the transparent insulating layer 40 . Therefore, in the effective pixel P<b>12 , light incident from the back side of the solid-state imaging device 900 reaches the photodiode PD in the semiconductor substrate 20 . On the other hand, since the second light shielding layer 920 is provided between the adjacent effective pixels P12, the incidence of light from the adjacent effective pixels P12 can be prevented.

As shown in FIG. 1B, the solid-state imaging device 900 includes a pixel region R10 and a circuit region R20 in plan view from the light incident surface side. The circuit region R20 is a region in which a logic circuit for signal processing is arranged. The circuit region R20 is provided outside the pixel region R10. In the example shown in FIG. 1B, the circuit region R20 is provided so as to surround the rectangular pixel region R10.

The circuit region 20 has logic circuits for processing image signals generated by the pixels PX (FIG. 1A) of the pixel region R10. The processing of the image signal in the circuit area 20 may be analog/digital conversion, for example.

As described above, the pixel region R10 includes the OPB pixel region R11 in which the OPB pixel P11 is formed and the effective pixel region R12 in which the effective pixel P12 is formed. In the example shown in FIG. 1B, the OPB pixel region R11 is provided along the upper and lower sides of the rectangular effective pixel region R12.

Light incident on the effective pixel P12 reaches the photodiode PD formed on the semiconductor substrate 20 . Therefore, the image signal generated by the effective pixel P12 is an image signal corresponding to the incident light of the solid-state imaging device 900, that is, an image signal based on the object.

On the other hand, the light that has entered the OPB pixel P11 does not reach the photodiode PD in the semiconductor substrate 20 . Therefore, the image signal generated by the OPB pixel P11 is an image signal in a light-shielded state, and can serve as a reference for the black level of the output image signal in the solid-state imaging device 900. FIG. Specifically, by subtracting the image signal generated by the OPB pixel P11 from the image signal generated by the effective pixel P12, an image signal having the image signal generated by the OPB pixel P11 as a black level can be generated. . The image signal generated by the OPB pixel P11 can also be used to measure dark current in the pixel PX. A "dark current" is a current based on charges generated by factors other than photoelectric conversion by incident light. Dark current can generate noise in an image signal. By measuring the dark current using the OPB pixel P11 and subtracting it from the image signal generated by the effective pixel P12, noise in the image signal based on the dark current can be reduced. Subtraction of these image signals can be performed in the circuit region R20 described above.

A noise reduction technique using the OPB pixel P11 as described above is known. However, in order to further reduce noise, the present inventors have earnestly studied a technique capable of suppressing an increase in dark current that can cause noise. As a result, the inventor noted that the heat generated in the circuit region R20 may be transmitted to the pixel region R10, thereby increasing the dark current. We have completed this technology.

2. Solid-state imaging device of this technology

Next, the solid-state imaging device of the present technology will be described. In the drawings referred to below, elements or members that are the same as or equivalent to the elements or members in "1. Conventional solid-state imaging device" are denoted by the same reference numerals, and overlapping descriptions are omitted as necessary. do. For elements or members that are not particularly described below, please refer to the description in "1. Conventional solid-state imaging device" above.

2-1. 1st embodiment

A configuration of the solid-state imaging device 1 according to the first embodiment of the present technology will be described with reference to FIG. 2 . FIG. 2 is a schematic cross-sectional view showing part of the solid-state imaging device 1 according to the first embodiment. As an example, a case where the solid-state imaging device 1 is a back-illuminated CMOS-type solid-state imaging device will be described below. In the solid-state imaging device 1 shown in FIG. 2, the upper side is the light incident surface side (rear surface side), and the lower side is the surface side facing the light incident surface (front surface side).

The solid-state imaging device 1 has a semiconductor substrate 20 . A semiconductor substrate 20 is formed with a pixel region R10 including an OPB pixel region R11 and an effective pixel region R12, and a circuit region R20. In a plan view from the light incident surface side of the solid-state imaging device 1, the circuit region R20 is provided outside the pixel region R10. For example, as in the conventional solid-state imaging device 900 shown in FIG. 1B, in a plan view from the light incident surface side of the solid-state imaging device 1, the circuit region R20 surrounds the rectangular pixel region R10. may be provided. Also, the OPB pixel region R11 may be provided along the upper and lower sides of the rectangular effective pixel region R12.

As shown in FIG. 2, the solid-state imaging device 1 includes an OPB pixel region R11, an effective pixel region R12, and a circuit region R20. The OPB pixel region R11 has a first light shielding layer 60, and the first light shielding layer 60 has a first convex structure 63 including a first convex portion 61 on the light incident surface side. The effective pixel region R12 may have a second light shielding layer 70, for example. The circuit region R20 may have a third light shielding layer 80, for example.

The first light shielding layer 60 is provided, for example, on the light incident surface side of the transparent insulating layer 40 in the OPB pixel region R11. That is, in the OPB pixel region R11, the transparent insulating layer 40 and the first light shielding layer 60 may be provided in this order on the light incident surface side of the semiconductor substrate 20. FIG. Another layer may be further provided between the semiconductor substrate 20 and the first light shielding layer 60 .

The first light shielding layer 60 extends parallel to the transparent insulating layer 40 and is provided to cover the OPB pixel P11. Light incident from the back side of the solid-state imaging device 1 is blocked by the first light shielding layer 60 and does not reach the photodiodes PD in the semiconductor substrate 20 .

The second light shielding layer 70 is provided, for example, on the light incident surface side of the transparent insulating layer 40 in the effective pixel region R12. The second light shielding layer 70 extends parallel to the transparent insulating layer 40 and is provided between adjacent effective pixels P12. Another layer may be further provided between the semiconductor substrate 20 and the second light shielding layer 70 . When the second light shielding layer 70 is seen in a plan view from the light incident surface side, the second light shielding layer 70 is formed in a grid pattern between adjacent effective pixels P12. The second light shielding layer 70 is not provided in the portion corresponding to the photodiode PD on the light incident surface side of the transparent insulating layer 40 . Therefore, in the effective pixel P<b>12 , light incident from the back side of the solid-state imaging device 1 reaches the photodiode PD in the semiconductor substrate 20 . On the other hand, since the second light shielding layer 70 is provided between the adjacent effective pixels P12, the incidence of light from the adjacent effective pixels P12 can be prevented.

The third light shielding layer 80 is provided, for example, on the light incident surface side of the transparent insulating layer 40 in the circuit region R20. That is, in the circuit region R20, the transparent insulating layer 40 and the third light shielding layer 80 may be provided in this order on the light incident surface side of the semiconductor substrate 20. FIG. Another layer may be further provided between the semiconductor substrate 20 and the third light shielding layer 80 .

One or more light shielding layers selected from the first light shielding layer 60, the second light shielding layer 70, and the third light shielding layer 80 may be provided continuously. In the present specification, "provided continuously" means to be provided continuously without a break. For example, the first light shielding layer 60 and the third light shielding layer 80 shown in FIG. 2 are provided continuously. For example, by continuously forming a plurality of light shielding layers using the same material, the light shielding film can be efficiently formed.

A first convex structure 63 including a first convex portion 61 is provided on the light incident surface side of the first light shielding layer 60 . In this specification, the term "convex part" (first convex part, second convex part, and third convex part) refers to a part artificially formed to protrude from other parts. From the viewpoint of manufacturing technology, it is difficult to make the light incident surface of the light shielding layer (the first light shielding layer, the second light shielding layer, and the third light shielding layer) a strictly smooth surface. There may be slight undulations. The undulations include a slightly raised portion on the light incident surface of the light shielding layer, and the height of the raised portion can be, for example, about 20 nm to 30 nm. However, such raised portions that are not artificially formed do not correspond to the "projections" in this specification.

The first convex structure 63 contributes to suppressing an increase in dark current caused by heat generation in the circuit region R20 in the solid-state imaging device 1 . Since the surface area of the first light shielding layer 60 is increased by providing the first convex structures 63 on the first light shielding layer 60, the heat dissipation of the first light shielding layer 60 can be improved. Heat transferred from the circuit region R20 to the OPB pixel region R11 can be effectively dissipated by the first light shielding layer 60. FIG. Therefore, an increase in dark current caused by the heat can be suppressed.

In order to further suppress the increase in dark current, the second light shielding layer 70 preferably has a second convex structure (not shown) including a second convex portion on the light incident surface side. Accordingly, the surface area of the second light shielding layer 70 may be increased, and the heat dissipation of the second light shielding layer 70 may be improved. The heat transferred from the circuit region R20 to the OPB pixel region R11 can also be efficiently dissipated from the effective pixel region R12 adjacent to the OPB pixel region R11. Therefore, an increase in dark current caused by the heat can be further suppressed.

In order to further suppress the increase in dark current, the third light shielding layer 80 preferably has a third convex structure 83 including a third convex portion 81 on the light incident surface side. Accordingly, the surface area of the third light shielding layer 80 may be increased, and the heat dissipation of the third light shielding layer 80 may be improved. Heat generated in the circuit region R20 can be efficiently dissipated by the third light shielding layer 80. FIG. Therefore, heat transmitted from the circuit region R20 to the OPB pixel region R11 is reduced, and an increase in dark current caused by the heat can be further suppressed.

In the solid-state imaging device 1, the OPB pixel region R11 may not have the on-chip lens 50 in order to further suppress the increase in dark current. Heat can easily escape from the first light shielding layer 60, and the heat dissipation property of the first light shielding layer 60 can be improved. As a result, an increase in dark current can be suppressed as described above.

FIG. 3 is a schematic cross-sectional view showing part of a modification of the solid-state imaging device 1 according to the first embodiment. A solid-state imaging device 1A shown in FIG. 3 is a modification of the solid-state imaging device 1 shown in FIG. In the solid-state imaging device 1A, the first light shielding layer 60 in the OPB pixel region R11 has a first convex structure 63 including a first convex portion 61 on the light incident surface side. However, although not shown, the third light shielding layer in the circuit area does not have the third convex structure on the light incident surface side.

The shape of the first convex structure 63 of the solid-state imaging device 1 will be described with reference to FIG. 2 again. The first convex structure 63 includes the first convex portion 61 as described above. The number of first protrusions 61 may be one or more. The first convex structure 63 may include a first concave portion 62 in addition to the first convex portion 61 . For example, as shown in FIG. 2 , the first convex structure 63 may include a plurality of first convex portions 61 and first concave portions 62 positioned between adjacent first convex portions 61 . By providing the plurality of first protrusions 61 in the first protrusion structure 63 in this way, the surface area of the first light shielding layer 60 can be further increased, and the heat dissipation of the first light shielding layer 60 can be further improved. .

The shape of the first convex structure 63 will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of the first convex structure 63 in the first light shielding layer 60. As shown in FIG. As shown in FIG. 4A , the first projecting structure 63 includes, for example, a plurality of first projecting portions 61 that are rectangular in cross section and flat first recesses located between the adjacent first projecting portions 61. 62 and . The first convex portion 61, which is rectangular in cross section, may have, for example, a prismatic shape or a columnar shape. 2 and 3 have the same shape as the first convex structure 63 shown in FIG. 4A. Further, as shown in FIG. 4B, the first convex structure 63a includes, for example, a plurality of triangular first convex portions 61a in a cross-sectional view and flat first convex portions 61a positioned between adjacent first convex portions 61a. 1 recess 62 . The first convex portion 61a, which is triangular in cross section, may have, for example, a pyramid shape or a conical shape.

The shape of the first convex structure 63 is not limited to the shape illustrated in FIG. The shape of the first projecting structure 63 is such that, for example, a plurality of first projecting portions 61a (FIG. 4B) having a triangular shape in a cross-sectional view are connected without spacing (without providing the flat first recesses 62). The shape may be provided. Further, the shape of the first concave portion 62 may be a shape other than a flat shape, and may be a shape having a depression, for example. The recess can be formed, for example, by cutting the light incident surface of the first light shielding layer 60 . The surface area of the first light shielding layer 60 can be further increased by having the first concave portion 62 having a hollow. Further, for example, another layer or component that can contribute to improving heat dissipation may be further formed between the light incident surface of the first light shielding layer 60 and the first convex portion 61 .

The lower limit of the height of the first projection 61 is, for example, 50 nm or more, preferably 100 nm or more, more preferably 150 nm or more, and even more preferably 180 nm or more. Such a height is preferable in order to further improve the heat dissipation of the first light shielding layer 60 . Also, the upper limit of the height of the first convex portion 61 may be appropriately set by those skilled in the art in consideration of, for example, ease of manufacture, efficiency of heat dissipation, size of the solid-state imaging device 1, and the like. The upper limit of the height may be, for example, 300 nm or less, 250 nm or less, or 220 nm or less. The numerical range of the height of the first convex portion 61 may be a combination selected from these lower limit values and upper limit values.

The lower limit of the height of the first convex portion 61 is, for example, 1.5 times or more, preferably 2.0 times or more, more preferably 2.5 times the surface area of the light incident surface of the first light shielding layer 60. More preferably, the height may be 3.0 times or more. Such a height is preferable in order to further improve the heat dissipation of the first light shielding layer 60 . Also, the upper limit of the height of the first convex portion 61 may be appropriately set by those skilled in the art in consideration of, for example, ease of manufacture, efficiency of heat dissipation, size of the solid-state imaging device 1, and the like. The upper limit of the height is the height at which the surface area of the light incident surface of the first light shielding layer 60 is, for example, 5.0 times or less, 4.5 times or less, 4.0 times or less, or 3.0 times or less. may be The numerical range of the height of the first convex portion 61 may be a combination selected from these lower limit values and upper limit values.

With reference to FIG. 2 again, the shapes of the second convex structure (not shown) and the third convex structure 83 of the solid-state imaging device 1 will be described. The second convex structure includes a second convex portion (not shown) as described above. The third convex structure 83 includes the third convex portion 81 as described above. The shape of the second protruding structure and the third protruding structure 83 may be the same as the shape of the first protruding structure described above. That is, the description regarding the shape of the first protruding structure 63 also applies to the shapes of the second protruding structure and the third protruding structure 83 . For example, the second convex structure may include a second concave portion in addition to the second convex portion. For example, the third convex structure 83 may include the third concave portion 82 in addition to the third convex portion 81 . However, in the solid-state imaging device 1, the first protruding structure 63, the second protruding structure, and the third protruding structure 83 may have different shapes from each other, may have different shapes partially, or may all have different shapes. They may have the same shape.

Further, the numerical range of the height of the second convex portion (not shown) and the third convex portion 81 may be the same numerical range as the height of the first convex portion 61 described above. That is, the description regarding the height of the first convex portion 61 also applies to the heights of the second convex portion and the third convex portion 81 . However, in the solid-state imaging device 1, the heights of the first convex portion 61, the second convex portion, and the third convex portion 81 may be different from each other, may be partially different, or may be the same. There may be.

The shapes of the first protruding structure 63, the second protruding structure 73, and the third protruding structure 83 will be further described with reference to FIG. 5A to 5C are schematic plan views of the light-shielding layers of the solid-state imaging devices 1, 1B, and 1C, respectively, viewed from the light incident surface side. In FIG. 5, light gray portions represent convex portions, and dark gray portions represent concave portions or the light incident surface of the light shielding layer. The solid-state imaging device 1 in FIG. 5A, the solid-state imaging device 1B in FIG. 5B, and the solid-state imaging device 1C in FIG. and a circuit region R20 having the third light shielding layer 80 .

In the solid-state imaging device 1 shown in FIG. 5A, the first light shielding layer 60 has the first convex structure 63 on the light incident surface side, and the third light shielding layer 80 has the third convex structure 83 on the light incident surface side. The second light shielding layer 70 does not have a convex structure on the light incident surface side, and the light incident surface of the second light shielding layer 70 is flat.

A large number of first protrusions 61 are arranged on the first protrusion structure 63 shown in FIG. 5A. As used herein, the term “large number” refers to so many that it is impossible to count, or so many that it is possible to count but requires considerable effort or time to count. Flat first recesses 62 are formed between adjacent first protrusions 61 . That is, in the first convex structure 63, a large number of first convex portions 61 and a large number of flat first concave portions 62 are arranged. In addition, in the first convex structure 63, the first convex portions 61 and the first concave portions 62 are alternately arranged.

The third convex structure 83 may have a shape similar to the first convex structure 61, as shown in FIG. 5A. That is, in the third convex structure 83, a large number of third convex portions 81 and a large number of flat third concave portions 82 may be arranged, and the third convex portions 81 and the third concave portions 82 are arranged alternately. It can be.

The heights of the first convex portion 61 and the third convex portion 81 may be the same, for example. The heights of the light incident surfaces of the first recess 62, the third recess 82, and the second light shielding layer 70 may be, for example, the same. The first light shielding layer 60 and the third light shielding layer 80 may be provided continuously. The first light shielding layer 60 and the second light shielding layer 70 may be provided continuously. The first protruding structure 61 and the third protruding structure 81 may be provided continuously.

A solid-state imaging device 1B shown in FIG. 5B is different from the solid-state imaging device 1 shown in FIG. 5A in that the second light shielding layer 70 has a second convex structure 73 on the light incident surface side. Differences between FIG. 5B and FIG. 5A will be described below. Configurations that are not described may be the same as those of the solid-state imaging device 1 shown in FIG. 5A. A large number of second convex portions 71 are arranged on the second convex structure 73 of the solid-state imaging device 1B shown in FIG. 5B. Flat second recesses 72 are formed between adjacent second protrusions 71 . That is, in the second convex structure 73, a large number of second convex portions 71 and a large number of flat second concave portions 72 are arranged. In addition, in the second convex structure 73, the second convex portions 71 and the second concave portions 72 are alternately arranged. The heights of the first convex portion 61, the second convex portion 71, and the third convex portion 81 may be the same, for example. The heights of the first recess 62, the second recess 72, and the third recess 82 may be the same, for example. The first protruding structure 61, the second protruding structure 73, and the third protruding structure 81 may be provided continuously.

A solid-state imaging device 1C shown in FIG. 5C differs from the solid-state imaging device 1 shown in FIG. 5A in that a first convex structure 63A and a third convex structure 83A are provided. Differences between FIG. 5C and FIG. 5A will be described below. Configurations that are not described may be the same as those of the solid-state imaging device 1 shown in FIG. 5A. In the first convex structure 63A of the solid-state imaging device 1C shown in FIG. 5C, a plurality of linear first convex portions 61A are arranged in parallel. The “linear” shape of the convex portion means that the convex portion has a linear shape in plan view of the solid-state imaging device (for example, in a plan view as shown in FIG. 5C). The linear shape may be, for example, linear, curved, polygonal, or a combination thereof. The plurality of linear first protrusions 61A are preferably arranged at regular intervals. A flat and linear first concave portion 62A is formed between adjacent linear first convex portions 61A. That is, in the first convex structure 63A, a plurality of linear first convex portions 61A and a plurality of flat and linear first concave portions 62A are arranged. Also, in the first convex structure 63A, the first convex portions 61A and the first concave portions 62A are alternately arranged. The plurality of first protrusions 61A and the plurality of first recesses 62A may be a large number of first protrusions 61A and a large number of first recesses 62A, respectively.

The third protruding structure 83A may have the same shape as the first protruding structure 61A, as shown in FIG. 5C. That is, in the third convex structure 83A, a plurality (or a large number) of linear third convex portions 81A and a plurality (or a large number) of flat and linear third concave portions 82A may be arranged, and The third protrusions 81A and the third recesses 82A may be alternately arranged.

The light-shielding layers (the first light-shielding layer, the second light-shielding layer, and the third light-shielding layer) described in detail above are formed of a light-shielding material (light-shielding material). The light shielding material includes, for example, metals such as tungsten (W), titanium (Ti), copper (Cu), tantalum (Ta), and aluminum (Al), titanium nitride (TiN), tantalum nitride (TaN), It may be one or a combination of two or more selected from metal nitrides such as tungsten nitride (WN) and aluminum nitride (AlN). The light-shielding materials used for the first light-shielding layer, the second light-shielding layer, and the third light-shielding layer may be different or the same.

The convex structures (the first convex structure, the second convex structure, and the third convex structure) may be made of a material different from that of the light shielding layers (the first light shielding layer, the second light shielding layer, and the third light shielding layer). . For example, the convex structure may be made of a material having higher heat dissipation than the light shielding layer in order to more effectively suppress an increase in dark current. On the other hand, the convex structure may be made of the same material as the light shielding layer from the viewpoint of ease of manufacture. For example, the first convex structure may be made of the same material as the first light shielding layer. The second convex structure may be made of the same material as the second light shielding layer. The third convex structure may be made of the same material as the third light shielding layer. Further, the convex structures (the first convex structure, the second convex structure, and the third convex structure) and the light shielding layers (the first light shielding layer, the second light shielding layer, and the third light shielding layer) are all made of the same material. may By using a common material in this way, the convex structure and the light shielding layer can be efficiently formed.

The configuration of the solid-state imaging device 1 will be further described with reference to FIG. 2 again. As shown in FIG. 2 , the solid-state imaging device 1 may have a connecting portion 90 connecting the semiconductor substrate 20 and the third light shielding layer 80 . Further, the solid-state imaging device 1 may have a connecting portion 90 connecting the semiconductor substrate 20 and the first light shielding layer 60 . That is, the solid-state imaging device 1 may have the connecting portion 90 that connects the semiconductor substrate 20 and the first light shielding layer 60 and/or the third light shielding layer 80 . The communication portion 90 has a surface (front side) facing the light incident surface of the first light shielding layer 60 and/or a surface (front side) facing the light incident surface of the third light shielding layer 80 and the light incident surface of the semiconductor substrate 20. It may be provided so as to penetrate the transparent insulating layer 40 between the planes and . The contact part 90 may prevent arcing from occurring due to floating of the first light shielding layer 60 in the OPB pixel region R11. Note that FIG. 3 shows a solid-state imaging device 1A that does not have the communication section 90 as a modified example.

The cross-sectional shape of the communication portion 90 will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view showing the communication portion 90. As shown in FIG. In FIG. 6, the upper side is the light incident surface side (rear surface side), and the lower side is the surface side (surface side) facing the light incident surface. FIG. 6A shows a contact portion 90 as an example, and FIG. 6B shows a contact portion 90a as another example.

As shown in FIG. 6A, the end portion 91 of the connecting portion 90 may be positioned on or near the inside of the light incident surface of the semiconductor substrate 20 . On the other hand, as shown in FIG. 6B, the end portion 91a of the connecting portion 90a may be positioned away from the light incident surface of the semiconductor substrate 20 and its inner vicinity. In this way, since the connecting portion 90a is provided deep in the semiconductor substrate 20, the heat dissipation of the light shielding layer (the first light shielding layer 60 and/or the third light shielding layer 80) in which the connecting portion 90a is provided is improved. can be improved.

An arrangement example of the communication unit 90 will be described with reference to FIG. 7 . 7A to 7C are schematic plan views of the solid-state imaging devices 1D to 1F, respectively, viewed from the light incident surface side. A connecting portion 90 of the solid-state imaging device 1D shown in FIG. 7A is formed in a linear shape surrounding the pixel region R10 in a plan view and is arranged between the adjacent pixel region R10 and circuit region R20. The solid-state imaging device 1E shown in FIG. 7B has a plurality of communication sections 90. As shown in FIG. All of the plurality of communication portions 90 are formed in a linear shape surrounding the pixel region R10 in a plan view, and are arranged at equal intervals. The connecting portion 90 of the solid-state imaging device 1F shown in FIG. 7C is formed on the entire surface of the circuit region R20 surrounding the pixel region R10. Thus, the number of communication units 90 may be one or more. Further, the shape of the communication portion 90 is not particularly limited, and may be linear or planar, for example.

A method for manufacturing the solid-state imaging device according to the first embodiment will be described with reference to FIGS. First, an example of the procedure for forming the second light shielding layer 70, the third light shielding layer 80, and the communication portion 90 will be described with reference to FIG. 8A to 8D are schematic cross-sectional views showing the manufacturing process of the solid-state imaging device according to the first embodiment. In the solid-state imaging device shown in FIG. 8, the upper side is the light incident surface side (rear side), and the lower side is the surface side (front side) facing the light incident surface. In each of FIGS. 8A-8I, the effective pixel region R12 is shown on the left, and the circuit region 20 is shown on the right.

First, a transparent insulating layer 40 is formed on the light incident surface (back surface) of the semiconductor substrate 20 by atomic layer deposition (ALD) using a material having light transmittance and insulating properties (FIG. 8A). Next, a resist R is formed on the transparent insulating layer 40 using photolithography (FIG. 8B). The resist R in the circuit region R20 has an opening at a position corresponding to the connecting portion 90 in plan view. Using the formed resist R as an etching mask, the transparent insulating layer 40 is etched. After that, the resist R is removed (FIG. 8C).

A light shielding layer is formed on the transparent insulating layer 40 using a light shielding material. Specifically, the second light shielding layer 70 is formed in the effective pixel region R12. A third light shielding layer 80 is formed in the circuit region R20 (FIG. 8D). A portion of the third light shielding layer 80 penetrates the transparent insulating layer 40 and is in contact with the semiconductor substrate 20 . A portion that penetrates the transparent insulating layer 40 is a connecting portion 90 that connects the third light shielding layer 80 and the semiconductor substrate 20 .

A resist R is formed on the second light shielding layer 70 and the third light shielding layer 80 using a photolithographic technique (FIG. 8E). The resist R in the effective pixel region R12 has openings at positions corresponding to the photodiodes (not shown) in plan view. Using the formed resist R as an etching mask, the second light shielding layer 70 is etched. After that, the resist R is removed (FIG. 8F).

A film 95 is formed using silicon oxide (SiO ₂ ) or the like on the second light shielding layer 70 and the third light shielding layer 80 (FIG. 8G). A resist R is formed on the film 95 using a photolithographic technique (FIG. 8H). Using the formed resist R as an etching mask, the film 95 is etched. After that, the film 95 is ground and planarized by CMP (Chemical Mechanical Polish) (FIG. 8I).

Through the above procedure, the second light shielding layer 70, the third light shielding layer 80, and the communication portion 90 can be formed. In addition, the first light shielding layer 60 can be formed by the same procedure as the second light shielding layer 70 .

Next, with reference to FIG. 9, an example of a procedure for forming the first convex structure 63 including the first convex portion 61 and the second convex structure 73 including the second convex portion 71 will be described. 9A to 9D are schematic cross-sectional views showing the manufacturing process of the solid-state imaging device according to the first embodiment. In the solid-state imaging device shown in FIG. 9, the upper side is the light incident surface side (rear side), and the lower side is the surface side (front side) facing the light incident surface. In each of FIGS. 9A-9E, adjacent OPB pixel region R11 and effective pixel region R12 are shown. The process shown in FIG. 9A assumes that the film 95 is formed in the OPB pixel region R11 and the effective pixel region R12 by the procedure shown in FIG. 8 described above. That is, FIG. 9A assumes that the planarized film 95 is formed on the first light shielding layer 60 and the second light shielding layer 70 by the procedure shown in FIG.

First, a resist R is formed on the film 95 using photolithography (FIG. 9A). The resist R has openings at positions corresponding to the first protrusions 61 and the second protrusions 71 in plan view. Using the formed resist R as an etching mask, the film 95 is etched. After that, by removing the resist R, a vertical hole 95a is formed in the film 95 (FIG. 9B).

Light shielding layers 61a and 71a are collectively formed on the film 95 by CVD (Chemical Vapor Deposition) using a light shielding material (FIG. 9C). At this time, the vertical holes 95a (FIG. 9B) of the film 95 are filled with the light shielding material. Next, the light shielding layers 61a and 71a are ground by CMP to remove the light shielding layers 61a and 71a on the film 95 (FIG. 9D). The film 95 is then removed by etchback (FIG. 9E).

Through the above procedure, the first convex structure 63 including the first convex portion 61 and the second convex structure 73 including the second convex portion 71 can be formed. The third convex structure 83 including the third convex portion 81 in the circuit region R20 can also be formed by the same procedure.

2-2. Second embodiment

In the solid-state imaging device according to the first embodiment, the pixel region R10 and the circuit region R20 are provided on the same semiconductor substrate 20. As shown in FIG. However, the solid-state imaging device according to the present technology may be a stacked solid-state imaging device in which the circuit region R20 is provided on a semiconductor substrate different from the pixel region R10, and a plurality of semiconductor substrates are stacked. Hereinafter, as a solid-state imaging device according to the second embodiment of the present technology, a stacked and back-illuminated CMOS-type solid-state imaging device will be described as an example.

The configuration of the solid-state imaging device 2 according to the second embodiment will be described with reference to FIG. FIG. 10 is a schematic diagram showing a laminated structure of semiconductor substrates in a solid-state imaging device 2 according to the second embodiment. In the drawings referred to below, elements or members that are the same as or equivalent to the elements or members of the above “2-1. do. For elements or members that are not specifically described below, please refer to the description in the above "2-1. First embodiment."

As shown in FIG. 10 , the solid-state imaging device 2 may include a first semiconductor substrate 25 and a second semiconductor substrate 26 . 10A and 10B show examples of different laminate structures.

In the example shown in FIG. 10A, a pixel region R10 including an OPB pixel region and an effective pixel region, and a control region R30 for driving pixels and various other controls are formed in the first semiconductor substrate 25. In the example shown in FIG. A circuit region R20 in which a logic circuit is arranged is formed in the second semiconductor substrate 26. As shown in FIG. The solid-state imaging device 2 is configured by stacking the first semiconductor substrate 25 and the second semiconductor substrate 26 and electrically connecting them to each other.

In the example shown in FIG. 10B, a pixel region R10 is formed on the first semiconductor substrate 25. In the example shown in FIG. A circuit region R20 and a control region R30 are formed in the second semiconductor substrate 26. As shown in FIG. The solid-state imaging device 2 is configured by stacking the first semiconductor substrate 25 and the second semiconductor substrate 26 and electrically connecting them to each other.

A configuration of a solid-state imaging device 2 according to a second embodiment of the present technology will be described with reference to FIG. 11 . FIG. 11 is a schematic cross-sectional view showing part of the solid-state imaging device 2 according to the second embodiment. In the solid-state imaging device 2 shown in FIG. 11, the upper side is the light incident surface side (rear surface side), and the lower side is the surface side facing the light incident surface (front surface side).

The solid-state imaging device 2 has a first semiconductor substrate 25 and a second semiconductor substrate 26 . The first semiconductor substrate 25 is provided at the position of the semiconductor substrate 20 (FIG. 2) of the first embodiment. The second semiconductor substrate 26 is provided on the surface side of the solid-state imaging device 2 . Since the circuit region R20 is located on the surface side facing the light incident surface of the solid-state imaging device 2 in this way, the circuit region R20 of the solid-state imaging device 2 does not include the third light shielding layer 80 described in the first embodiment. do not have.

The solid-state imaging device 2 includes an OPB pixel region R11 having a first light shielding layer 60. As shown in FIG. The first light shielding layer 60 has a first convex structure 63 including a first convex portion 61 and a first concave portion 62 on the light incident surface side. Moreover, the solid-state imaging device 2 includes an effective pixel region R12 having the second light shielding layer 70 . Although not shown, the second light shielding layer 70 may have a second convex structure including a second convex portion on the light incident surface side.

The solid-state imaging device 2 may have, for example, a connecting portion 90 connecting the first semiconductor substrate 25 on which the OPB pixel region R11 is formed and the first light shielding layer 60 .

3. Usage example of a solid-state imaging device to which this technology is applied

FIG. 12 is a diagram illustrating a usage example of the solid-state imaging device of the present technology.

The solid-state imaging device of the present technology can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-rays. That is, as shown in FIG. 12, for example, the field of appreciation for photographing images to be used for viewing, the field of transportation, the field of home appliances, the field of medicine/health care, the field of security, the field of beauty, the field of sports, and the like. The solid-state imaging device of the present technology can be used for devices used in the fields of agriculture, agriculture, and the like.

Specifically, in the field of viewing, for example, the solid-state imaging device of this technology is used in devices for capturing images for viewing, such as digital cameras, smartphones, and mobile phones with camera functions. can be used.

In the field of transportation, for example, in-vehicle sensors that capture images of the front, back, surroundings, and interior of a vehicle, and monitor running vehicles and roads for safe driving such as automatic stopping and recognition of the driver's condition. The solid-state imaging device of the present technology can be used for devices used for transportation, such as surveillance cameras that monitor traffic, distance sensors that measure distances between vehicles, and the like.

In the field of home appliances, for example, the present technology can be applied to devices used in home appliances, such as television receivers, refrigerators, and air conditioners, in order to photograph user gestures and perform device operations according to the gestures. A solid-state imager can be used.

In the field of medicine and healthcare, the solid-state imaging device of this technology can be used in medical and healthcare devices such as endoscopes and devices that perform angiography by receiving infrared light. can be used.

In the field of security, for example, the solid-state imaging device of the present technology can be used in security devices such as surveillance cameras for crime prevention and cameras for person authentication.

In the field of beauty, for example, the solid-state imaging device of the present technology can be used in devices used for beauty, such as a skin measuring device that photographs skin and a microscope that photographs scalp.

In the field of sports, for example, the solid-state imaging device of the present technology can be used in devices used for sports, such as action cameras and wearable cameras for sports.

In the field of agriculture, for example, the solid-state imaging device of the present technology can be used in devices used for agriculture, such as cameras for monitoring the state of fields and crops.

Next, a usage example of the solid-state imaging device of the present technology will be specifically described. The solid-state imaging device of the present technology can be applied to all types of electronic devices having imaging functions, such as camera systems such as digital still cameras and video cameras, and mobile phones having imaging functions. FIG. 13 shows a schematic configuration of an electronic device 102 (camera) as an example. The electronic device 102 is, for example, a video camera capable of capturing still images or moving images, and includes a solid-state imaging device 101, an optical system (optical lens) 310, a shutter device 311, and the solid-state imaging device 101 and the shutter device 311. It has a drive unit 313 for driving and a signal processing unit 312 .

The optical system 310 guides image light (incident light) from a subject to the pixel portion of the solid-state imaging device 101 . This optical system 310 may be composed of a plurality of optical lenses. The shutter device 311 controls a light irradiation period and a light shielding period for the solid-state imaging device 101 . The drive unit 313 controls the transfer operation of the solid-state imaging device 101 and the shutter operation of the shutter device 311 . The signal processing unit 312 performs various signal processing on the signal output from the solid-state imaging device 101 . The video signal Dout after signal processing is stored in a storage medium such as a memory, or output to a monitor or the like.

4. Example of application to an endoscopic surgery system

This technology can be applied to various products. For example, the technology may be applied to an endoscopic surgical system.

FIG. 14 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technique (the present technique) according to the present disclosure can be applied.

FIG. 14 shows an operator (doctor) 11131 performing an operation on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000 . As illustrated, an endoscopic surgery system 11000 includes an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy treatment instrument 11112, and a support arm device 11120 for supporting the endoscope 11100. , and a cart 11200 loaded with various devices for endoscopic surgery.

An endoscope 11100 is composed of a lens barrel 11101 whose distal end is inserted into a body cavity of a patient 11132 and a camera head 11102 connected to the proximal end of the lens barrel 11101 . In the illustrated example, an endoscope 11100 configured as a so-called rigid scope having a rigid lens barrel 11101 is illustrated, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel. good.

The tip of the lens barrel 11101 is provided with an opening into which an objective lens is fitted. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel 11101 by a light guide extending inside the lens barrel 11101, where it reaches the objective. Through the lens, the light is irradiated toward the observation object inside the body cavity of the patient 11132 . Note that the endoscope 11100 may be a straight scope, a perspective scope, or a side scope.

An optical system and an imaging element are provided inside the camera head 11102, and reflected light (observation light) from an observation target is focused on the imaging element by the optical system. The imaging device photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is transmitted to a camera control unit (CCU: Camera Control Unit) 11201 as RAW data.

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

The display device 11202 displays an image based on an image signal subjected to image processing by the CCU 11201 under the control of the CCU 11201 .

The light source device 11203 is composed of a light source such as an LED (light emitting diode), for example, and supplies the endoscope 11100 with irradiation light for imaging a surgical site or the like.

Input device 11204 is an input interface for endoscopic surgery system 11000 . The user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204 . For example, the user inputs an instruction or the like to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) by the endoscope 11100 .

The treatment instrument control device 11205 controls driving of the energy treatment instrument 11112 for tissue cauterization, incision, blood vessel sealing, or the like. The pneumoperitoneum device 11206 inflates the body cavity of the patient 11132 for the purpose of securing the visual field of the endoscope 11100 and securing the operator's working space, and injects gas into the body cavity through the pneumoperitoneum tube 11111. send in. The recorder 11207 is a device capable of recording various types of information regarding surgery. The printer 11208 is a device capable of printing various types of information regarding surgery in various formats such as text, images, and graphs.

The light source device 11203 for supplying irradiation light to the endoscope 11100 for photographing the surgical site can be composed of, for example, a white light source composed of an LED, a laser light source, or a combination thereof. When a white light source is configured by a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high accuracy. It can be carried out. Further, in this case, the observation target is irradiated with laser light from each of the RGB laser light sources in a time division manner, and by controlling the drive of the imaging device of the camera head 11102 in synchronization with the irradiation timing, each of RGB can be handled. It is also possible to pick up images by time division. According to this method, a color image can be obtained without providing a color filter in the imaging device.

Further, the driving of the light source device 11203 may be controlled so as to change the intensity of the output light every predetermined time. By controlling the drive of the imaging device of the camera head 11102 in synchronism with the timing of the change in the intensity of the light to obtain an image in a time-division manner and synthesizing the images, a high dynamic A range of images can be generated.

Also, the light source device 11203 may be configured to be capable of supplying light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in body tissues, by irradiating light with a narrower band than the irradiation light (i.e., white light) during normal observation, the mucosal surface layer So-called Narrow Band Imaging is performed in which a predetermined tissue such as a blood vessel is imaged with high contrast. Alternatively, in special light observation, fluorescence observation may be performed in which an image is obtained from fluorescence generated by irradiation with excitation light. In fluorescence observation, the body tissue is irradiated with excitation light and the fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally injected into the body tissue and the body tissue is examined. A fluorescence image can be obtained by irradiating excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to be able to supply narrowband light and/or excitation light corresponding to such special light observation.

FIG. 15 is a block diagram showing an example of functional configurations of the camera head 11102 and CCU 11201 shown in FIG.

The camera head 11102 has a lens unit 11401 , an imaging section 11402 , a drive section 11403 , a communication section 11404 and a camera head control section 11405 . The CCU 11201 has a communication section 11411 , an image processing section 11412 and a control section 11413 . The camera head 11102 and the CCU 11201 are communicably connected to each other via a transmission cable 11400 .

A lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101 . Observation light captured from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401 . A lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

The imaging device constituting the imaging unit 11402 may be one (so-called single-plate type) or plural (so-called multi-plate type). When the image pickup unit 11402 is configured as a multi-plate type, for example, image signals corresponding to RGB may be generated by each image pickup element, and a color image may be obtained by synthesizing the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for respectively acquiring right-eye and left-eye image signals corresponding to 3D (dimensional) display. The 3D display enables the operator 11131 to more accurately grasp the depth of the living tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multi-plate type, a plurality of systems of lens units 11401 may be provided corresponding to each imaging element.

Also, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102 . For example, the imaging unit 11402 may be provided inside the lens barrel 11101 immediately after the objective lens.

The drive unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405 . Thereby, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

The communication unit 11404 is configured by a communication device for transmitting/receiving various information to/from the CCU 11201 . The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400 .

Also, the communication unit 11404 receives a control signal for controlling driving of the camera head 11102 from the CCU 11201 and supplies it to the camera head control unit 11405 . The control signal includes, for example, information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and/or information to specify the magnification and focus of the captured image. Contains information about conditions.

Note that the imaging conditions such as the frame rate, exposure value, magnification, and focus may be appropriately designated by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. good. In the latter case, the endoscope 11100 is equipped with so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

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

The communication unit 11411 is configured by a communication device for transmitting/receiving various information to/from the camera head 11102 . The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400 .

The communication unit 11411 also transmits a control signal for controlling driving of the camera head 11102 to the camera head 11102 . Image signals and control signals can be transmitted by electrical communication, optical communication, or the like.

The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data transmitted from the camera head 11102 .

The control unit 11413 performs various controls related to the imaging of the surgical site and the like by the endoscope 11100 and the display of the captured image obtained by the imaging of the surgical site and the like. For example, the control unit 11413 generates control signals for controlling driving of the camera head 11102 .

In addition, the control unit 11413 causes the display device 11202 to display a picked-up image showing the surgical site and the like based on the image signal subjected to image processing by the image processing unit 11412 . At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 detects the shape, color, and the like of the edges of objects included in the captured image, thereby detecting surgical instruments such as forceps, specific body parts, bleeding, mist during use of the energy treatment instrument 11112, and the like. can recognize. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition result to display various types of surgical assistance information superimposed on the image of the surgical site. By superimposing and presenting the surgery support information to the operator 11131, the burden on the operator 11131 can be reduced and the operator 11131 can proceed with the surgery reliably.

A transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable of these.

Here, in the illustrated example, wired communication is performed using the transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may be performed wirelessly.

An example of an endoscopic surgery system to which the present technology can be applied has been described above. The present technology can be applied to the endoscope 11100, the camera head 11102 (the imaging unit 11402 thereof), and the like among the configurations described above. For example, the solid-state imaging device according to the present technology can be applied to the imaging unit 11402 . By applying the present technology to (the imaging unit 11402 of) the endoscope 11100 and the camera head 11102, the performance of the endoscope 11100 and the camera head 11102 (the imaging unit 11402 of) can be improved. Become.

Although an endoscopic surgical system has been described as an example here, the present technology may also be applied to other systems such as a microscopic surgical system.

5. Example of application to mobile objects

This technology can be applied to various products. For example, the present technology may be implemented as a device mounted on any type of moving object such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility, airplanes, drones, ships, and robots. .

FIG. 16 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology according to the present disclosure can be applied.

Vehicle control system 12000 comprises a plurality of electronic control units connected via communication network 12001 . In the example shown in FIG. 16, the vehicle control system 12000 includes a drive train control unit 12010, a body system control unit 12020, an outside information detection unit 12030, an inside information detection unit 12040, and an integrated control unit 12050. Also, as the functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio/image output unit 12052, and an in-vehicle network I/F (Interface) 12053 are illustrated.

Drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the driving system control unit 12010 includes a driving force generator for generating driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism to adjust and a brake device to generate braking force of the vehicle.

Body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, winkers or fog lamps. In this case, body system control unit 12020 can receive radio waves transmitted from a portable device that substitutes for a key or signals from various switches. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, etc. of the vehicle.

External information detection unit 12030 detects information external to the vehicle in which vehicle control system 12000 is mounted. For example, the vehicle exterior information detection unit 12030 is connected with an imaging section 12031 . The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the exterior of the vehicle, and receives the captured image. The vehicle exterior information detection unit 12030 may perform object detection processing or distance detection processing such as people, vehicles, obstacles, signs, or characters on the road surface based on the received image.

The imaging unit 12031 is an optical sensor that receives light and outputs an electric signal according to the amount of received light. The imaging unit 12031 can output the electric signal as an image, and can also output it as distance measurement information. Also, the light received by the imaging unit 12031 may be visible light or non-visible light such as infrared rays.

The vehicle interior information detection unit 12040 detects vehicle interior information. The in-vehicle information detection unit 12040 is connected to, for example, a driver state detection section 12041 that detects the state of the driver. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 detects the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041. It may be calculated, or it may be determined whether the driver is dozing off.

The microcomputer 12051 calculates control target values for the driving force generator, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and controls the drive system control unit. A control command can be output to 12010 . For example, the microcomputer 12051 realizes the functions of ADAS (Advanced Driver Assistance System) including collision avoidance or shock mitigation of vehicle, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane deviation warning, etc. Cooperative control can be performed for the purpose of

In addition, the microcomputer 12051 controls the driving force generator, the steering mechanism, the braking device, etc. based on the information about the vehicle surroundings acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, so that the driver's Cooperative control can be performed for the purpose of autonomous driving, etc., in which vehicles autonomously travel without depending on operation.

Further, the microcomputer 12051 can output a control command to the body system control unit 12030 based on information outside the vehicle acquired by the information detection unit 12030 outside the vehicle. For example, the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detection unit 12030, and performs cooperative control aimed at anti-glare such as switching from high beam to low beam. It can be carried out.

The audio/image output unit 12052 transmits at least one of audio and/or image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle. In the example of FIG. 16, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are illustrated as output devices. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

FIG. 17 is a diagram showing an example of the installation position of the imaging unit 12031. As shown in FIG.

In FIG. 17, imaging units 12101, 12102, 12103, 12104, and 12105 are provided as the imaging unit 12031. In FIG.

The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and windshield of the vehicle 12100, for example. An image pickup unit 12101 provided in the front nose and an image pickup unit 12105 provided above the windshield in the passenger compartment mainly acquire images in front of the vehicle 12100 . Imaging units 12102 and 12103 provided in the side mirrors mainly acquire side images of the vehicle 12100 . An imaging unit 12104 provided in the rear bumper or back door mainly acquires an image behind the vehicle 12100 . The imaging unit 12105 provided above the windshield in the passenger compartment is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

Note that FIG. 17 shows an example of the imaging range of the imaging units 12101 to 12104 . The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided in the front nose, the imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided in the side mirrors, respectively, and the imaging range 12114 The imaging range of an imaging unit 12104 provided in the rear bumper or back door is shown. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

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

For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 determines the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and changes in this distance over time (relative velocity with respect to the vehicle 12100). , it is possible to extract, as the preceding vehicle, the closest three-dimensional object on the traveling path of the vehicle 12100, which runs at a predetermined speed (for example, 0 km/h or more) in substantially the same direction as the vehicle 12100. can. Furthermore, the microcomputer 12051 can set the inter-vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including following stop control) and automatic acceleration control (including following start control). In this way, cooperative control can be performed for the purpose of automatic driving in which the vehicle runs autonomously without relying on the operation of the driver.

For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 converts three-dimensional object data related to three-dimensional objects to other three-dimensional objects such as motorcycles, ordinary vehicles, large vehicles, pedestrians, and utility poles. It can be classified and extracted and used for automatic avoidance of obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into those that are visible to the driver of the vehicle 12100 and those that are difficult to see. Then, the microcomputer 12051 judges the collision risk indicating the degree of danger of collision with each obstacle, and when the collision risk is equal to or higher than the set value and there is a possibility of collision, an audio speaker 12061 and a display unit 12062 are displayed. By outputting an alarm to the driver via the drive system control unit 12010 and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be performed.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not the pedestrian exists in the captured images of the imaging units 12101 to 12104 . Such recognition of a pedestrian is performed by, for example, a procedure for extracting feature points in images captured by the imaging units 12101 to 12104 as infrared cameras, and performing pattern matching processing on a series of feature points indicating the outline of an object to determine whether or not the pedestrian is a pedestrian. This is done by a procedure that determines When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and recognizes the pedestrian, the audio image output unit 12052 outputs a rectangular outline for emphasis to the recognized pedestrian. is superimposed on the display unit 12062 . Also, the audio/image output unit 12052 may control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

An example of a vehicle control system to which the present technology can be applied has been described above. The present technology can be applied to, for example, the imaging unit 12031 among the configurations described above. Specifically, the solid-state imaging device according to the present technology can be applied to the imaging unit 12031 . By applying the present technology to the imaging unit 12031, the performance of the imaging unit 12031 can be improved.

Note that the present technology is not limited to the above-described embodiments, usage examples, and application examples, and various modifications are possible without departing from the gist of the present technology.

Moreover, the effects described in this specification are only examples and are not limited, and other effects may also occur.

This technique can also take the following configurations.
[1]
including an optical black pixel region having a first light shielding layer, an effective pixel region, and a circuit region;
The first light shielding layer has a first convex structure including a first convex portion on the light incident surface side,
Solid-state imaging device.
[2]
the effective pixel region has a second light shielding layer,
The solid-state imaging device according to [1], wherein the second light shielding layer has a second convex structure including a second convex portion on the light incident surface side.
[3]
the circuit region has a third light shielding layer,
The solid-state imaging device according to [1] or [2], wherein the third light shielding layer has a third convex structure including a third convex portion on the light incident surface side.
[4]
The solid-state imaging device according to any one of [1] to [3], wherein a large number of first protrusions are arranged in the first protrusion structure.
[5]
The solid-state imaging device according to [2], wherein a large number of the second convex portions are arranged in the second convex structure.
[6]
The solid-state imaging device according to [3], wherein in the third convex structure, a large number of the third convex portions are arranged.
[7]
The solid-state imaging device according to any one of [1] to [6], wherein in the first convex structure, a plurality of linear first convex portions are arranged in parallel.
[8]
The solid-state imaging device according to [3], wherein in the third convex structure, a plurality of linear third convex portions are arranged in parallel.
[9]
The solid-state imaging device according to any one of [1] to [8], wherein the first convex structure is made of the same material as the first light shielding layer.
[10]
The solid-state imaging device according to [2], wherein the second convex structure is made of the same material as the second light shielding layer.
[11]
The solid-state imaging device according to [3], wherein the third convex structure is made of the same material as the third light shielding layer.
[12]
The solid-state imaging device according to any one of [1] to [11], wherein the optical black pixel area does not have an on-chip lens.
[13]
The solid-state imaging device according to any one of [1] to [12], further comprising a connecting portion that connects the semiconductor substrate on which the optical black pixel region is formed and the first light shielding layer.
[14]
The solid-state imaging device according to [3], further comprising a connecting portion that connects the semiconductor substrate on which the circuit region is formed and the third light shielding layer.
[15]
The solid-state imaging device according to any one of [1] to [12], wherein the first convex portion has a height of 100 nm or more.
[16]
The solid-state imaging device according to [2], wherein the second convex portion has a height of 100 nm or more.
[17]
The solid-state imaging device according to [3], wherein the third convex portion has a height of 100 nm or more.

1, 1A to 1F, 2 solid-state imaging device 20 semiconductor substrate 21 pixel separation section 25 first semiconductor substrate 26 second semiconductor substrate 30 multilayer wiring layer 40 transparent insulating layer 50 on-chip lens 60 first light shielding layers 61, 61a, 61A 1 convex part 62, 62A 1st concave part 63, 63a, 63A 1st convex structure 70 2nd light shielding layer 71 2nd convex part 72 2nd concave part 73 2nd convex structure 80 3rd light shielding layer 81, 81A 3rd convex part 82 , 82A Third concave portions 83, 83A Third convex structures 90, 90a Connecting portion R10 Pixel region R11 Optical black pixel region (OPB pixel region)
R12 Effective pixel region R20 Circuit region PD Photodiode PX Pixel P11 Optical black pixel (OPB pixel)
P12 Effective pixels 900 Conventional solid-state imaging device

Claims (17)

including an optical black pixel region having a first light shielding layer, an effective pixel region, and a circuit region;
The first light shielding layer has a first convex structure including a first convex portion on the light incident surface side,
Solid-state imaging device. the effective pixel region has a second light shielding layer,
2. The solid-state imaging device according to claim 1, wherein said second light shielding layer has a second convex structure including a second convex portion on the light incident surface side. the circuit region has a third light shielding layer,
2. The solid-state imaging device according to claim 1, wherein said third light shielding layer has a third convex structure including a third convex portion on the light incident surface side. 2. The solid-state imaging device according to claim 1, wherein a large number of said first protrusions are arranged in said first protrusion structure. 3. The solid-state imaging device according to claim 2, wherein a large number of said second convex portions are arranged in said second convex structure. 4. The solid-state imaging device according to claim 3, wherein a large number of said third convex portions are arranged in said third convex structure. 2. The solid-state imaging device according to claim 1, wherein said first convex structure has a plurality of linear first convex portions arranged in parallel. 4. The solid-state imaging device according to claim 3, wherein said third convex structure has a plurality of said linear third convex portions arranged in parallel. 2. The solid-state imaging device according to claim 1, wherein said first convex structure is made of the same material as said first light shielding layer. 3. The solid-state imaging device according to claim 2, wherein said second convex structure is made of the same material as said second light shielding layer. 4. The solid-state imaging device according to claim 3, wherein said third convex structure is made of the same material as said third light shielding layer. 2. The solid-state imaging device according to claim 1, wherein said optical black pixel area does not have an on-chip lens. 2. The solid-state imaging device according to claim 1, further comprising a connecting portion connecting the semiconductor substrate on which the optical black pixel region is formed and the first light shielding layer. 4. The solid-state imaging device according to claim 3, further comprising a connecting portion connecting said semiconductor substrate on which said circuit region is formed and said third light shielding layer. 2. The solid-state imaging device according to claim 1, wherein the height of said first convex portion is 100 nm or more. 3. The solid-state imaging device according to claim 2, wherein the height of said second convex portion is 100 nm or more. 4. The solid-state imaging device according to claim 3, wherein the third convex portion has a height of 100 nm or more.

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