Light detection device and electronic apparatus

Abstract

Provided is a light detection device capable of achieving desired pixel characteristics while suppressing generation of dark current. Specifically, the light detection device is provided with: a semiconductor substrate; a plurality of photoelectric conversion units formed on the semiconductor substrate in a two-dimensional array form; and an inter-pixel isolation structure formed in a region between the photoelectric conversion units of the semiconductor substrate. The inter-pixel isolation structure includes a first inter-pixel isolation structure as a part of an effective pixel region and a second inter-pixel isolation structure as a part of a light-shielding pixel region surrounding a periphery of the effective pixel region. A first conductor is arranged in the first inter-pixel isolation structure, and a second conductor electrically connected to the first conductor and applied with a negative bias voltage is arranged in the second inter-pixel isolation structure. In addition, the first conductor and the second conductor are formed by using conductive materials different from each other.

Description

Technical Field

[0001] This technology (based on the technology disclosed herein) relates to optical detection devices and electronic devices. Background Technology

[0002] Conventionally, for example, photodetectors have been proposed that include a semiconductor substrate and an inter-pixel isolation structure. The semiconductor substrate has multiple photoelectric conversion units, and the inter-pixel isolation structure has trenches formed in the region between the photoelectric conversion units of the semiconductor substrate and conductors disposed in the trenches (see, for example, Patent Document 1). In the photodetector described in Patent Document 1, by applying a negative bias voltage to the conductors, the peripheral portion of the inter-pixel isolation structure is brought into a high hole concentration state, and the generation of dark current is suppressed. List of cited references Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2022-148841 Summary of the Invention The problem the invention aims to solve

[0004] In addition to suppressing the generation of dark current, this photodetector is also required to achieve the desired pixel characteristics.

[0005] The purpose of this disclosure is to provide a light detection device and electronic device that can achieve desired pixel characteristics while suppressing dark current generation. Solution to the problem

[0006] The light detection device disclosed herein includes: (a) a semiconductor substrate, (b) a plurality of photoelectric conversion units formed in a two-dimensional array on the semiconductor substrate, and (c) an inter-pixel isolation structure formed in a region between the photoelectric conversion units on the semiconductor substrate, wherein (d) the inter-pixel isolation structure includes a first inter-pixel isolation structure as part of an effective pixel region and a second inter-pixel isolation structure as part of a light-shielding pixel region surrounding the periphery of the effective pixel region, (e) a first conductor disposed in the first inter-pixel isolation structure, (f) a second conductor disposed in the second inter-pixel isolation structure, the second conductor being electrically connected to the first conductor and subjected to a negative bias voltage, and (g) the first conductor and the second conductor are formed by using conductive materials different from each other.

[0007] The electronic device disclosed herein includes a light detection device comprising: (a) a semiconductor substrate; (b) a plurality of photoelectric conversion units formed in a two-dimensional array on the semiconductor substrate; and (c) an inter-pixel isolation structure formed in a region between the photoelectric conversion units on the semiconductor substrate, wherein (d) the inter-pixel isolation structure includes a first inter-pixel isolation structure as part of an effective pixel region and a second inter-pixel isolation structure as part of a light-shielding pixel region surrounding the periphery of the effective pixel region; (e) a first conductor is arranged in the first inter-pixel isolation structure; (f) a second conductor is arranged in the second inter-pixel isolation structure, the second conductor being electrically connected to the first conductor and subjected to a negative bias voltage; and (g) the first conductor and the second conductor are formed by using different conductive materials. Attached Figure Description

[0008] Figure 1 This is a diagram showing the overall structure of the solid-state camera device according to the first embodiment. Figure 2 This is a diagram showing the planar structure of one of the four corners of a pixel region. Figure 3 It shows along Figure 2 The diagram shows the cross-sectional structure of the solid-state camera device, taken from line AA. Figure 4 It shows along Figure 2 The diagram shows the cross-sectional structure of the solid-state camera device as shown by line BB. Figure 5 This is a diagram illustrating a method for manufacturing a solid-state camera device. Figure 6 This is a diagram illustrating a method for manufacturing a solid-state camera device. Figure 7 This is a diagram illustrating a method for manufacturing a solid-state camera device. Figure 8 This is a diagram illustrating a method for manufacturing a solid-state camera device. Figure 9 This is a diagram illustrating a method for manufacturing a solid-state camera device. Figure 10 This is a diagram showing the planar structure of one of the four corners of the pixel region 2 of the solid-state imaging device according to the second embodiment. Figure 11 It shows along Figure 10 The figure shows the cross-sectional structure of the solid-state camera device of the second embodiment, taken from line CC. Figure 12 It shows along Figure 10The figure shows the cross-sectional structure of the solid-state camera device of the second embodiment, taken from line DD. Figure 13 It shows along Figure 2 The figure shows the cross-sectional structure of the solid-state camera device of the third embodiment, taken from line AA. Figure 14 It shows along Figure 2 The figure shows the cross-sectional structure of the solid-state camera device of the third embodiment, as shown by line BB. Figure 15 This is a diagram illustrating a schematic construction of an electronic device according to the fourth embodiment. Figure 16 This is a diagram illustrating an example of a schematic construction of an endoscope system. Figure 17 It shows Figure 16 A block diagram illustrating an example of the functional configuration of a camera and camera control unit (CCU). Figure 18 This is a diagram illustrating an example of a schematic construction of a microsurgical system. Detailed Implementation

[0009] In the following text, reference will be made to Figures 1 to 18 Examples of light detection devices and electronic devices according to embodiments of this disclosure are described below. Embodiments of this disclosure will be described in the following order. Note that this disclosure is not limited to the examples below. Furthermore, the effects described in this specification are illustrative rather than limiting, and other effects may exist.

[0010] 1. First Implementation Plan: Solid-State Camera Device 1-1 Overall Structure of Solid State Camera 1-2 Construction of Main Components 1-3 Manufacturing method of solid-state imaging device 2. Second Implementation Plan: Solid-State Camera Device 2-1 Construction of Main Components 3. Third Implementation Plan: Solid-State Camera Device 3-1 Construction of Main Components 3-2 Variation Example 4. Fourth Implementation Plan: Application Examples of Electronic Devices 5. Fifth Implementation Plan: Application Examples of Mobile Bodies

[0011] <1. First Implementation Plan> [1-1 Overall Structure of Solid State Camera] The solid-state imaging device 1 (a "light detection device" in a broad sense) according to the first embodiment of this disclosure will be described. Figure 1This is a diagram showing the overall structure of the solid-state imaging device 1 according to the first embodiment. Figure 1 The solid-state imaging device 1 in the image is a back-illuminated complementary metal-oxide-semiconductor (CMOS) image sensor. For example... Figure 15 As shown, the solid-state imaging device 1 (1002) captures image light (incident light) from the subject through the lens group 1001, converts the amount of incident light that forms an image on the imaging surface into an electrical signal in units of pixels, and outputs the electrical signal as a pixel signal. like Figure 1 As shown, the solid-state imaging device 1 includes a pixel area 2, a vertical driving circuit 3, a column signal processing circuit 4, a horizontal driving circuit 5, an output circuit 6, and a control circuit 7.

[0012] Pixel region 2 includes multiple pixels 8 arranged in a two-dimensional array. Pixel 8 includes a photoelectric conversion unit PD (see reference). Figure 3 And multiple pixel transistors (e.g., transfer transistors, reset transistors, amplification transistors, and selection transistors). Furthermore, such as Figure 2 As shown, pixel region 2 includes an effective pixel region 12 and a light-shielding pixel region 13 located around the effective pixel region 12. The light-shielding pixel region 13 includes optical black (OPB) pixels and dummy pixels as light-shielding pixels, which are used to obtain a reference signal for optical black level. The vertical drive circuit 3 includes, for example, a shift register that sequentially selects pixels 8 in the pixel region 2 row by row by outputting selection pulses, for example, to the pixel drive wiring 9, and outputs the pixel signal of the selected pixel 8 to the column signal processing circuit 4 via the vertical signal line 10. Examples of pixel signals include signals obtained from the charge (e.g., electrons) generated by the photoelectric conversion unit PD.

[0013] The column signal processing circuit 4 is arranged for each column of pixels 8, and performs signal processing such as noise removal on the signal output from the pixels 8 in a row for each column of pixels. As signal processing, for example, correlated double sampling (CDS) and analog-to-digital (AD) conversion can be used to remove fixed-pattern noise specific to pixels. The horizontal drive circuit 5 includes, for example, a shift register, which sequentially selects the column signal processing circuit 4 by outputting horizontal drive pulses to the column signal processing circuit 4, and causes the selected column signal processing circuit 4 to output the processed pixel signal to the horizontal signal line 11.

[0014] The output circuit 6 performs signal processing on the pixel signals sequentially output from each column signal processing circuit 4 via the horizontal signal line 11, and outputs the pixel signals. Various types of digital signal processing, such as buffering, black level adjustment, and column offset correction, can be used for signal processing. For example, black level adjustment can be achieved by subtracting a reference signal for the optical black level obtained from the light-shielding pixel 8 (OPB pixel) of the light-shielding pixel region 13 from the pixel signal obtained from the pixel signal obtained from the effective pixel region 12 (effective pixel), thereby correcting the black level of the pixel signal to "0". The control circuit 7 generates clock and control signals that serve as references for the operation of the vertical drive circuit 3, column signal processing circuit 4, and horizontal drive circuit 5, based on the vertical synchronization signal, horizontal synchronization signal, and master clock signal (not shown). Then, the control circuit 7 outputs the generated clock and control signals to the vertical drive circuit 3, column signal processing circuit 4, and horizontal drive circuit 5, etc.

[0015] [1-2 Construction of the main components] Next, the detailed structure of the solid-state camera device 1 will be explained. Figure 2 This is a diagram showing the planar structure of one of the four corners of pixel region 2. Figure 2 In this design, the structure above the light-shielding metals 18 and 19 is omitted, making the light-shielding metals 18 and 19 clearly visible. Furthermore, Figure 3 It shows along Figure 2 The diagram shows the cross-sectional structure of the solid-state imaging device 1, taken from line AA. Note that... Figure 3 This illustrates performing pupil correction to position the light-shielding metal 18 towards the center of pixel region 2. Figure 3 The lower side of the photoelectric conversion unit (PD) moves, and the photoelectric conversion unit (PD) is located below the light-shielding metal 18. Furthermore, Figure 4 It shows along Figure 2 The diagram shows the cross-sectional structure of the solid-state camera device 1 as shown by line BB. like Figure 2 As shown, pixel region 2 includes an effective pixel region 12 located in the center of pixel region 2 and a light-shielding pixel region 13 surrounding the effective pixel region 12. The effective pixel area 12 corresponds to the area that forms the image of the subject. For example... Figure 3 As shown, in the effective pixel region 12, the solid-state imaging device 1 includes a semiconductor substrate 14, and an insulator 15, a first conductor 16, an insulating film 17, and a light-shielding metal 18 are sequentially stacked on the light-receiving surface of the semiconductor substrate 14 (hereinafter also referred to as the "back side S1"; broadly referred to as the "first side"). Note that although not described... Figure 3The light-receiving surface of the light-shielding metal 18a (hereinafter also referred to as "back side S2") can be formed, but color filters and on-chip lenses can be formed thereon. Furthermore, a wiring layer 20 is arranged on the surface of the semiconductor substrate 14 opposite to the back side S1 (hereinafter also referred to as "front side S3"; broadly also referred to as "second side"). Furthermore, the light-shielding pixel region 13 is the region surrounding the periphery of the effective pixel region 12. In the light-shielding pixel region 13, the solid-state imaging device 1 includes a semiconductor substrate 14 shared with the effective pixel region 12, and a light-shielding metal 19 is arranged on the back side S1 of the semiconductor substrate 14. Furthermore, a wiring layer 20 is arranged on the front side S3 of the semiconductor substrate 14.

[0016] The semiconductor substrate 14 is a substrate containing, for example, silicon (Si). The semiconductor substrate 14 is shared by the effective pixel region 12 and the light-shielding pixel region 13, and photoelectric conversion units (PDs) are formed in each region corresponding to each pixel 8. In other words, multiple photoelectric conversion units (PDs) are arranged in a two-dimensional array on the semiconductor substrate 14. The photoelectric conversion units (PDs) form photodiodes through a pn junction formed by a p-type semiconductor region and an n-type semiconductor region, and perform photoelectric conversion on incident light to generate charge. Furthermore, the generated charge accumulates in the electrostatic capacitance generated at the pn junction. Furthermore, in the semiconductor substrate 14, an inter-pixel isolation structure 21 is formed in the region between photoelectric conversion units (PDs). That is, the inter-pixel isolation structure 21 is formed in a lattice shape to surround each photoelectric conversion unit (PD). Moreover, the inter-pixel isolation structure 21 includes a first inter-pixel isolation structure 22, which is part of the effective pixel region 12, and a second inter-pixel isolation structure 23, which is part of the light-shielding pixel region 13. The first inter-pixel isolation structure 22 is formed from the back surface S1 of the semiconductor substrate 14 to the middle between the back surface S1 and the front surface S3. Furthermore, in the first inter-pixel isolation structure 22, a first conductor 16 is disposed from the back surface S1 to the middle between the back surface S1 and the front surface S3. Specifically, the first inter-pixel isolation structure 22 includes a trench 24 and an insulator 15 and a first conductor 16 disposed in the trench 24. The trench 24 is formed from the back surface S1 of the semiconductor substrate 14 to the middle between the back surface S1 and the front surface S3, and the sidewalls and bottom surface form the outline of the first inter-pixel isolation structure 22. Furthermore, the insulator 15 continuously covers the sidewalls of the trench 24 and the back surface S1 of the semiconductor substrate 14 in the effective pixel region 12. The insulator 15 on the back surface S1 side of the semiconductor substrate 14 extends to the boundary between the effective pixel region 12 and the light-shielding pixel region 13, such that the insulator 15 does not cover the back surface S1 of the light-shielding pixel region 13. As the material of the insulator 15 (insulating material), silicon oxide (SiO) can be used, for example.

[0017] Furthermore, the first conductor 16 is embedded in the space within the trench 24, specifically in the space between the sidewalls covered by the insulator 15. Therefore, portions of the first conductor 16 within the trench 24 are electrically integrated. Additionally, the first conductor 16 extends from the back surface S1 of the semiconductor substrate 14 to the bottom surface of the trench 24. Besides the space within the trench 24, the first conductor 16 also covers the region (grid-like region) of the light-receiving surface of the insulator 15 (hereinafter also referred to as "back surface S6") located on the back surface S1 of the semiconductor substrate 14 along the portion between the photoelectric conversion units PD. That is, the first conductor 16 is continuously arranged in the region along the portion between the photoelectric conversion units PD on the back surface S1 of the semiconductor substrate 14 in the first pixel isolation structure 22 and the effective pixel region 12. The formation range of the first conductor 16 on the back surface S6 side of the insulator 15 reaches the boundary between the effective pixel region 12 and the light-shielding pixel region 13, but does not reach the light-shielding pixel region 13. A conductive material can be used as the material for the first conductor 16. Examples include indium tin oxide (ITO). Furthermore, an STI 50 is formed in a grid shape along the first pixel isolation structure 22 between the end of the first pixel isolation structure 22 on the front side S3 and the front side S3 of the semiconductor substrate 14.

[0018] Furthermore, the second inter-pixel isolation structure 23 is formed to extend through the semiconductor substrate 14 from the back side S1 to the front side S3. Additionally, a conductor (hereinafter also referred to as "second conductor 25") is arranged from the back side S1 to the front side S3 in the second inter-pixel isolation structure. Specifically, the second inter-pixel isolation structure 23 includes a trench 26 and an insulator 27 and a second conductor 25 disposed in the trench 26. The trench 26 extends through the semiconductor substrate 14 from the back side S1 to the front side S3 and has sidewalls forming the shape of the second inter-pixel isolation structure 23. Furthermore, the insulator 27 continuously covers the sidewalls of the trench 26. For example, silicon oxide (SiO) can be used as the material for the insulator 27. Furthermore, the second conductor 25 is embedded in the space within the trench 26, specifically in the space between the sidewalls covered by the insulator 27. Therefore, portions of the second conductor 25 within the trench 26 are electrically integrated. Furthermore, the space between the sidewalls covered by the insulator 27 (i.e., the space in the second inter-pixel isolation structure 23) and the space between the insulators 15 in the first inter-pixel isolation structure 22 are connected to each other, and the second conductor 25 and the first conductor 16 are electrically connected such that their ends contact each other. Furthermore, the second conductor 25 is arranged to penetrate the semiconductor substrate 14 from the back side S1 to the front side S3. By penetrating the semiconductor substrate 14, the second conductor 25 is exposed on both the front side S3 and the back side S1 of the semiconductor substrate 14. Furthermore, a conductive material can be used as the material for the second conductor 25. Examples include doped polysilicon doped with boron (B), etc. That is, in the first embodiment, the first conductor 16 and the second conductor 25 are formed using different conductive materials. More specifically, the first conductor 16 is formed of a conductive material with a lower light absorption rate than the second conductor 25. The relationship between the light absorption rates of ITO and doped polycrystalline silicon is that the light absorption rate of ITO < the light absorption rate of doped polycrystalline silicon.

[0019] Furthermore, in the second conductor 25, the front side S3 is electrically connected to a power supply with a negative bias voltage, and a negative bias voltage is applied from the front side S3. By applying a negative bias voltage, the periphery of the second pixel isolation structure 23 in the light-shielding pixel region 13 can enter a high hole concentration state, and the generation of dark current can be suppressed. Figure 3 The diagram shows a case where a contact 28 formed on a portion of the front side S3 of the second conductor 25 is connected to the second conductor 25, and the second conductor 25 is connected to a power supply with a negative bias voltage via the contact 28. The insulating film 17 is formed to continuously cover the light-receiving surface of the first conductor 16 (hereinafter also referred to as "back side S4") and the portion of the back side S6 of the insulator where the first conductor 16 is not disposed.

[0020] A light-shielding metal 18 is disposed on the light-receiving surface (hereinafter also referred to as "back side S5") of the insulating film 17 in the effective pixel region 12, and is formed to cover the region along the portion between the photoelectric conversion units PD on the back side S5 of the insulating film 17 in the effective pixel region 12. Furthermore, a light-shielding metal 19 is disposed on the back side S1 of the semiconductor substrate 14 in the light-shielding pixel region 13, and is formed to cover the entire back side S1 of the semiconductor substrate 14 in the light-shielding pixel region 13. Furthermore, the opposing surface of the light-shielding metal 19 opposite to the back side S1 of the semiconductor substrate 14 (hereinafter also referred to as "front side S7") is electrically connected to the second conductor 25 exposed on the back side S1 of the semiconductor substrate 14 (that is, the end of the second conductor 25 on the back side S1). Furthermore, the end of the light-shielding metal 19 on the effective pixel region 12 side contacts and is electrically connected to the end of the portion of the first conductor 16 located on the back side S1 on the light-shielding pixel region 13 side. Therefore, the first conductor 16 and the second conductor 25 are electrically connected to each other via the light-shielding metal 19. Therefore, a negative bias voltage applied from the front side S3 to the second conductor 25 is applied to the first conductor 16 via the second conductor 25 and the light-shielding metal 19. That is, the light-shielding metal 19, used for the light-shielding of the photoelectric conversion unit PD in the light-shielding pixel region 13, forms the transmission path for the negative bias voltage. Therefore, in the effective pixel region 12, the periphery of the first inter-pixel isolation structure 22 can enter a high hole concentration state, and the generation of dark current can be suppressed. The materials for the light-shielding metals 18 and 19 can be, for example, tungsten (W), aluminum (Al), or copper (Cu). The light-shielding metals 18 and 19 are separated at the boundary between the effective pixel region 12 and the light-shielding pixel region 13 and are not electrically connected. The wiring layer 20 includes an interlayer insulating film and a multilayer wiring (not shown) stacked via the interlayer insulating film, and drives the pixel transistors (not shown) of each pixel 8 via the multilayer wiring.

[0021] In the solid-state imaging device 1 with the above-described structure, light is incident from the back side S1 of the semiconductor substrate 14. The incident light passes through an on-chip lens and a color filter (not shown), and the transmitted light is photoelectrically converted by the photoelectric conversion unit PD to generate charge. Then, the generated charge is used as a pixel signal from the vertical signal line 10 (see reference 10) formed by the wiring of the wiring layer 20. Figure 1 Output. Furthermore, in the solid-state imaging device 1 according to the first embodiment, the front S3 side end of the second conductor 25 in the second inter-pixel isolation structure 23 in the light-shielding pixel region 13 is electrically connected to a power supply with a negative bias voltage. Therefore, a negative bias voltage is applied to the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 via the second conductor 25 and the light-shielding metal 19, and the periphery of the first inter-pixel isolation structure 22 is brought into a high hole concentration state to suppress the generation of dark current.

[0022] Here, for example, we will consider the case where the same conductive material as the second conductor 25 in the second inter-pixel isolation structure 23 in the light-shielding pixel region 13 is embedded in the first conductor 16 of the first inter-pixel isolation structure 22 in the effective pixel region 12. That is, we assume that doped polysilicon is also used as the material of the first conductor 16. In this case, since polysilicon has the property of absorbing light, the incident light is absorbed by the first inter-pixel isolation structure 22 in the effective pixel region 12. Therefore, there is a possibility that the amount of light photoelectrically converted by the photoelectric conversion unit PD in the effective pixel region 12 is reduced and the sensitivity is decreased. On the other hand, in the solid-state imaging device 1 according to the first embodiment, the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 and the second conductor 25 in the second inter-pixel isolation structure 23 in the light-shielding pixel region 13 are formed using different conductive materials. Therefore, by selecting a conductive material as the conductive material of the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 according to the desired pixel characteristics, the characteristics of the pixel 8 can be improved. More specifically, in the first embodiment, the first conductor 16 is formed of a conductive material (ITO) with a lower light absorption rate than the second conductor 25. Therefore, in the effective pixel region 12, the absorption of incident light by the first inter-pixel isolation structure 22 can be suppressed, and the decrease in sensitivity of the pixel 8 can be suppressed. Furthermore, the second conductor 25 is formed of doped polysilicon. Here, the embeddability of doped polysilicon is superior to that of ITO. Therefore, when manufacturing the solid-state imaging device 1, the step of embedding the second conductor 25 in the space within the trench 26 of the second pixel isolation structure 23, i.e., in the narrow space penetrating the semiconductor substrate 14, can be performed relatively easily.

[0023] [1-3 Manufacturing Method of Solid State Imaging Device] Next, the manufacturing method of the solid-state camera device 1 according to the first embodiment will be described. First, such as Figure 5As shown, a semiconductor substrate 14 on which a second inter-pixel isolation structure 23 and a wiring layer 20 are formed is fabricated. Doped polysilicon is embedded in the second inter-pixel isolation structure 23 as a second conductor 25. Subsequently, trenches 24 of the first inter-pixel isolation structure 22 are formed on the back surface S1 of the fabricated semiconductor substrate 14 using photolithography and dry etching. Subsequently, an insulator 27 is formed to continuously cover the sidewalls of the formed trenches 24 and the back surface S1 of the semiconductor substrate 14. As a method for forming the insulator 27, chemical vapor deposition (CVD) or thermal oxidation can be used, for example.

[0024] Subsequently, as Figure 6 As shown, a first conductor 16 is formed to continuously cover the space between the sidewalls covered by the insulator 15 and the back surface S6 of the insulator 27. ITO, which has a lower light absorption rate than doped polycrystalline silicon, is used as the material for the first conductor 16. Subsequently, as... Figure 7 As shown, after an insulating film 17 is formed on the back surface S4 of the first conductor 16, a light-shielding metal 19 is formed on the surface to be formed (see reference). Figure 3 A resist mask 29 with an opening at the location of ). Subsequently, as Figure 8 As shown, etching is performed through the resist mask 29 to remove a portion of the first conductor 16 and the insulator 15, thereby exposing the back surface S1 of the semiconductor substrate 14. Therefore, the second conductor 25 is exposed on the back surface S1. Subsequently, the resist mask 29 is removed, and as shown... Figure 9 As shown, a film of constant thickness is formed on the entire back side S1 of the semiconductor substrate 14 using a material (e.g., tungsten (W)) of the light-shielding metal 19. Therefore, the front side S7 of the light-shielding metal 19 is electrically connected to the second conductor 25, and the end of the light-shielding metal 19 on the effective pixel region 12 side is electrically connected to the first conductor 16. Then, the contact 28 of the power supply connected to the negative bias voltage is connected to the first conductor 16 via the second conductor 25 and the light-shielding metal 19. Subsequently, the material of the formed light-shielding metal 19 is removed from the back side S5 of the insulating film 17 in the effective pixel region 12 to form the light-shielding metal 19. Afterward, a light-shielding metal 18 (see reference 1) is formed on the back side S5 of the insulating film 17 in the effective pixel region 12. Figure 3 Color filters and on-plate lenses, etc. Figure 3 The solid-state camera device 1 shown is manufactured through such a process.

[0025] <2. Second Implementation Plan> [2-1 Construction of Main Components] Next, the solid-state camera device 1 according to the second embodiment of this disclosure will be described. The overall structure of the solid-state camera device 1 according to the second embodiment is similar to... Figure 1 Similar to that in [the text], therefore its illustration will be omitted. Figure 10 It is consistent with the first implementation plan. Figure 2 The corresponding figure is a planar structure showing one of the four corners of the pixel region 2 of the solid-state imaging device 1 according to the second embodiment. Furthermore, Figure 11 It is consistent with the first implementation plan. Figure 3 The corresponding diagram shows the path along... Figure 10 A diagram showing the cross-sectional structure of the solid-state imaging device 1, taken from line CC. Furthermore, Figure 12 It is consistent with the first implementation plan. Figure 4 The corresponding diagram shows the path along... Figure 10 A diagram showing the cross-sectional structure of the solid-state imaging device 1, taken from line DD. Figure 10 , Figure 11 and Figure 12 In, with Figure 2 , Figure 3 and Figure 4 Corresponding parts are indicated by the same reference numerals, and redundant descriptions will be omitted. The solid-state imaging device 1 according to the second embodiment differs from the solid-state imaging device 1 according to the first embodiment in terms of the construction and materials of the first conductor 16 and the second conductor 25, as well as the construction of the light-shielding metal 18. Furthermore, in the solid-state imaging device 1 according to the third embodiment, the insulating film 17 is omitted.

[0026] like Figure 11 and Figure 12 As shown, the first conductor 16 is arranged from the back side S1 to the bottom surface of the trench 24 within the space within the trench 24, that is, in the space between the sidewalls covered by the insulator 15. Therefore, the first conductor 16 in each portion of the trench 24 is electrically integrated, and the back side S1 side of the first conductor 16 is exposed on the back side S1 of the semiconductor substrate 14. For example, doped polycrystalline silicon can be used as the material (conductive material) for the first conductor 16. Furthermore, the second conductor 25 is embedded in the space within the trench 26, specifically in the space between the sidewalls covered by the insulator 27. Therefore, each portion of the second conductor 25 in the trench 26 is electrically integrated. Furthermore, the second conductor 25 is arranged to penetrate the semiconductor substrate 14 from the back side S1 to the front side S3. By penetrating the semiconductor substrate 14, the second conductor 25 is exposed on both the front side S3 and the back side S1 of the semiconductor substrate 14. Furthermore, the same material as the light-shielding metal 19 can be used as the material (conductive material) for the second conductor 25, for example, tungsten (W). That is, in the second embodiment, the first conductor 16 is formed of a conductive material with a higher light absorption rate than the second conductor 25. The relationship between the light absorption rate of doped polycrystalline silicon and the light absorption rate of tungsten (W) is that the light absorption rate of doped polycrystalline silicon > the light absorption rate of tungsten (W). Furthermore, in the second conductor 25, the front side S3 is electrically connected to a negative bias voltage power supply via a contact portion 28, and a negative bias voltage is applied from the front side S3. By applying a negative bias voltage, the periphery of the second pixel isolation structure 23 in the light-shielding pixel region 13 can be made to enter a high hole concentration state, and the generation of dark current can be suppressed.

[0027] A light-shielding metal 18 is disposed on the back side S6 of the insulator 15 in the effective pixel region 12, and is formed to cover the region of the back side S6 of the insulator 15 in the effective pixel region 12 along the portion between the photoelectric conversion units PD. Furthermore, the surface of the light-shielding metal 18 opposite to the insulator 15 (hereinafter also referred to as the "front side S8") has a protrusion 30 penetrating the insulator 15 in the portion opposite to the first conductor 16, and is electrically connected in contact with the first conductor 16 exposed on the back side S1 of the semiconductor substrate 14 (i.e., the end of the first conductor 16 on the back side S1). Furthermore, a light-shielding metal 19 is disposed on the back side S1 of the semiconductor substrate 14 in the light-shielding pixel region 13, and is formed to cover the entire back side S1 of the semiconductor substrate 14 in the light-shielding pixel region 13. Furthermore, the front side S7 of the light-shielding metal 19 contacts and is electrically connected to the second conductor 25 exposed on the back side S1 of the semiconductor substrate 14 (i.e., the end of the second conductor 25 on the back side S1). Therefore, the first conductor 16 and the second conductor 25 are electrically connected to each other via light-shielding metals 18 and 19. Therefore, a negative bias voltage applied from the front side S3 to the second conductor 25 is applied to the first conductor 16 via the second conductor 25 and the light-shielding metals 18 and 19. In other words, the light-shielding metals 19 and 18, which are used to shield the photoelectric conversion unit PD in the light-shielding pixel region 13, form a transmission path for the negative bias voltage. Therefore, in the effective pixel region 12, the periphery of the first inter-pixel isolation structure 22 can enter a high hole concentration state, and the generation of dark current can be suppressed. For example, tungsten (W), aluminum (Al), or copper (Cu) can be used as the material for the light-shielding metals 18 and 19. Figure 11 This illustration shows a case where light-shielding metals 18 and 19, as well as the second conductor 25, are integrally formed using the same material. Light-shielding metals 18 and 19 are connected and integrally formed at the boundary between the effective pixel region 12 and the light-shielding pixel region 13.

[0028] Using the above-described structure, in the solid-state imaging device 1 according to the second embodiment, the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 and the second conductor 25 in the second inter-pixel isolation structure 23 in the light-shielding pixel region 13 are formed using different conductive materials. Therefore, by selecting a conductive material as the conductive material of the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 according to desired pixel characteristics, the characteristics of the pixel 8 can be improved. More specifically, in the second embodiment, the first conductor 16 is formed of a conductive material (doped polysilicon) with a higher light absorption rate than the second conductor 25. Therefore, in the effective pixel region 12, the absorption of incident light by the first inter-pixel isolation structure 22 can be improved, and optical color mixing can be more appropriately suppressed. Therefore, for example, when using a single-photon avalanche diode (SPAD) that generates current based on avalanche multiplication of incident photons as the photoelectric conversion unit PD, a structure where color mixing is more problematic than sensitivity is preferred.

[0029] <3. Third Implementation Plan> [3-1 Construction of Main Components] Next, the solid-state camera device 1 according to the third embodiment of this disclosure will be described. The overall structure of the solid-state camera device 1 according to the third embodiment is similar to... Figure 1 Similar to that in [the text], therefore its illustration will be omitted. Figure 13 It is consistent with the first implementation plan. Figure 3 The corresponding diagram shows the path along... Figure 2 A diagram showing the cross-sectional structure of the solid-state imaging device 1, taken from line AA. Furthermore, Figure 14 It is consistent with the first implementation plan. Figure 4 The corresponding diagram shows the path along... Figure 2 A diagram showing the cross-sectional structure of the solid-state imaging device 1, taken from line BB. Figure 13 and Figure 14 In, with Figure 3 and Figure 4 Corresponding parts are indicated by the same reference numerals, and redundant descriptions will be omitted. The solid-state camera device 1 according to the third embodiment differs from the solid-state camera device 1 according to the first embodiment in terms of the construction of the insulator 15 and the materials and construction of the first conductor 16 and the second conductor 25.

[0030] The insulator 15 continuously covers the sidewalls of the trench 24 in the effective pixel region 12 and the entire back surface S1 of the semiconductor substrate 14 (both the effective pixel region 12 and the light-shielding pixel region 13). like Figure 13 and Figure 14 As shown, the first conductor 16 is arranged from the back surface S1 to the bottom surface of the trench 24 in the space within the trench 24, that is, in the space between the sidewalls covered by the insulator 15. Therefore, each portion of the first conductor 16 in the trench 24 is electrically integrated. In addition to the space within the trench 24, the first conductor 16 also continuously covers the region (grid-like region) along the back surface S6 of the insulator 15 in the effective pixel region 12 along the portion between the photoelectric conversion units PD, and the entire back surface S6 of the insulator 15 in the light-shielding pixel region 13. That is, it is continuously arranged in the first inter-pixel isolation structure 22 in the region along the portion between the photoelectric conversion units PD on the back surface S1 of the semiconductor substrate 14 in the effective pixel region 12, and continuously arranged on the entire back surface S1 of the semiconductor substrate 14 in the light-shielding pixel region 13. Furthermore, in the light-shielding pixel region 13, the surface of the first conductor 16 opposite to the insulator 15 (hereinafter also referred to as "surface S9") has a protrusion 31 penetrating the insulator 15 in the portion opposite to the second conductor 25, and contacts the back surface S1 of the semiconductor substrate 14. Moreover, the material (conductive material) of the first conductor 16 can be, for example, ITO.

[0031] Furthermore, the second conductor 25 is embedded in the space within the trench 26, specifically in the space between the sidewalls covered by the insulator 27. Therefore, each portion of the second conductor 25 within the trench 26 is electrically integrated. Additionally, the second conductor 25 is arranged to penetrate the semiconductor substrate 14 from the back side S1 to the front side S3. By penetrating the semiconductor substrate 14, the second conductor 25 is exposed on both the front side S3 and the back side S1 of the semiconductor substrate 14. The end of the second conductor 25 exposed from the front side S3 is electrically connected to a negative bias voltage power supply via a contact portion 28, and a negative bias voltage is applied from the front side S3. By applying a negative bias voltage, the periphery of the second pixel isolation structure 23 in the light-shielding pixel region 13 can enter a high hole concentration state, and the generation of dark current can be suppressed.

[0032] Furthermore, the end of the second conductor 25 exposed from the back side S1 contacts and is electrically connected to the first conductor 16 located on the back side S1 of the semiconductor substrate 14 in the light-shielding pixel region 13. Therefore, the first conductor 16 and the second conductor 25 are electrically connected to each other without passing through the light-shielding metals 18 and 19. Thus, a negative bias voltage applied from the front side S3 to the first conductor 16 in the first inter-pixel isolation structure 22 is applied via the second conductor 25 and the first conductor 16 located on the back side S1. In other words, the first conductor 16 located on the back side S1 forms a transmission path for the negative bias voltage to the first conductor 16 in the first inter-pixel isolation structure 22. Therefore, in the effective pixel region 12, the periphery of the first inter-pixel isolation structure 22 can enter a high hole concentration state, and the generation of dark current can be suppressed. Furthermore, the material (conductive material) of the second conductor 25 can be, for example, tungsten (W). That is, in the third embodiment, the first conductor 16 is formed of a conductive material with a lower light absorption rate than the second conductor 25. The relationship between the light absorption rates of ITO and tungsten (W) is that the light absorption rate of ITO < the light absorption rate of tungsten.

[0033] Using the above-described structure, in the solid-state imaging device 1 according to the third embodiment, the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 and the second conductor 25 in the second inter-pixel isolation structure 23 in the light-shielding pixel region 13 are formed using different conductive materials. Therefore, by selecting a conductive material as the conductive material of the first conductor 16 in the first inter-pixel isolation structure 22 in the effective pixel region 12 according to desired pixel characteristics, the characteristics of the pixel 8 can be improved. More specifically, in the third embodiment, the first conductor 16 is formed of a conductive material (ITO) with a lower light absorption rate than the second conductor 25. Therefore, in the effective pixel region 12, the absorption of incident light by the first inter-pixel isolation structure 22 can be suppressed, and sensitivity can be improved. Furthermore, the first conductor 16 on the back side S1 of the semiconductor substrate 14 located in the light-shielding pixel region 13 serves as a transmission path for the negative bias voltage. Therefore, for example, compared to the case where the light-shielding metal 19 is used as the transmission path, it is not necessary to prepare materials for forming the transmission path separately from the material of the first conductor 16, and the increase in the number of steps that accompanies the formation of the transmission path can be suppressed.

[0034] [3-2 Variation Example] (1) Note that in the first, second and third embodiments, examples of forming a transmission path for a negative bias voltage on the back side S1 of the semiconductor substrate 14 have been described, but other configurations may also be used. For example, at the boundary between the trench 24 of the first inter-pixel isolation structure 22 and the trench 26 of the second inter-pixel isolation structure 23, the portion in which the first conductor 16 and the second conductor 25 in the trenches 24 and 26 are in direct contact can be used as a transmission path for the negative bias voltage. (2) Furthermore, examples of applying a negative bias voltage from the front side S3 of the second conductor 25 have been described in the first, second, and third embodiments, but other configurations may also be used. For example, a negative bias voltage may be applied from the back side S1 of the second conductor 25.

[0035] (3) In addition to the solid-state imaging device 1 described above as an image sensor, this technology can also be applied to all light detection devices, including distance measuring sensors, which can be called time-of-flight (ToF) sensors. A distance measuring sensor is a sensor that emits illumination light toward an object, detects the reflected light as illumination light reflected from the surface of the object, and calculates the distance to the object based on the time of flight from emitting the illumination light to receiving the reflected light. The light receiving pixel structure of the distance measuring sensor can adopt the structure of the pixel 8 described above.

[0036] <4. Fourth Implementation Plan> The technology disclosed herein (the technology) can be applied to various electronic devices. Figure 15 This is a diagram illustrating an example of the schematic construction of a camera device (camera or digital camera, etc.) as an electronic device applying this technology. like Figure 15 As shown, the imaging device 1000 includes a lens group 1001, a solid-state imaging device 1002 (solid-state imaging device 1 according to the first embodiment), a digital signal processor (DSP) circuit 1003, a frame memory 1004, a monitor 1005, and a memory 1006. The DSP circuit 1003, the frame memory 1004, the monitor 1005, and the memory 1006 are interconnected via a bus 1007.

[0037] The lens group 1001 guides the incident light (image light) from the subject to the solid-state imaging device 1002 to form an image on the light receiving surface (pixel area) of the solid-state imaging device 1002. The solid-state imaging device 1002 includes the CMOS image sensor according to the first embodiment described above. The solid-state imaging device 1002 converts the amount of incident light that forms an image on the light-receiving surface by the lens group 1001 into an electrical signal in units of pixels, and supplies the electrical signal as a pixel signal to the DSP circuit 1003. The DSP circuit 1003 performs predetermined image processing on the pixel signals supplied from the solid-state imaging device 1002. Then, the DSP circuit 1003 supplies the image signals of each frame after image processing to the frame memory 1004 to temporarily store the image signals in the frame memory 1004. Monitor 1005 includes, for example, a panel-type display device such as a liquid crystal panel or an organic electroluminescent (EL) panel. Monitor 1005 displays an image (moving image) of the subject based on the pixel signals of each frame temporarily stored in frame memory 1004. The memory 1006 includes DVDs or flash memory, etc. The memory 1006 reads and records pixel signals temporarily stored in the frame memory 1004 in units of frames.

[0038] Note that the electronic device to which the solid-state imaging device 1 can be applied is not limited to the imaging device 1000, and the solid-state imaging device 1 can also be applied to other electronic devices. Furthermore, the solid-state imaging device 1 according to the first embodiment is used as the solid-state imaging device 1002, but other configurations may also be adopted. For example, other light detection devices applying this technology can be used, such as the solid-state imaging device 1 according to the second or third embodiment, or the solid-state imaging device 1 according to a variant, etc.

[0039] <5. Fifth Implementation Plan> The technology disclosed herein (the Technology) can be applied to medical imaging systems. A medical imaging system is a medical system that uses imaging technology, such as an endoscope system or a microscope system.

[0040] [Endoscopic System] Will use Figure 16 and Figure 17 An example illustrating an endoscopic system. Figure 16 This is a diagram illustrating an example of a schematic construction of an endoscope system 5000 to which the technology according to this disclosure can be applied. Figure 17 This is a diagram showing an example of the construction of the endoscope 5001 and the camera control unit (CCU) 5039. Figure 16 This illustrates a scenario where the surgeon (e.g., a physician) 5067, acting as a participant in the surgery, uses an endoscope system 5000 to perform surgery on patient 5071 on bed 5069. Figure 16 As shown, the endoscope system 5000 includes an endoscope 5001 as a medical imaging device, a CCU 5039, a light source device 5043, a recording device 5053, an output device 5055, and a support device 5027 for supporting the endoscope 5001.

[0041] In endoscopic surgery, an insertion aid called a cannula 5025 is inserted into the patient 5071. Then, a scope 5003 connected to an endoscope 5001 and a surgical instrument 5021 are inserted into the patient 5071 through the cannula 5025. For example, the surgical instrument 5021 includes an energy device such as an electrocautery knife and forceps.

[0042] Surgical images, which are medical images obtained by the endoscope 5001 taking pictures of the inside of the patient 5071's body, are displayed on the display device 5041. While reviewing the surgical images displayed on the display device 5041, the surgeon 5067 uses surgical instruments 5021 to manipulate the surgical target. Medical images are not limited to surgical images; they can also be diagnostic images taken during diagnosis.

[0043] [Endoscope] Endoscope 5001 is a camera unit used to photograph the inside of the patient's body 5071, and for example, as Figure 17As shown, a camera 5005 includes a condensing optical system 50051 for converging incident light, a zoom optical system 50052 capable of optical zoom by changing the focal length of the camera unit, a focusing optical system 50053 capable of focus adjustment by changing the focal length of the camera unit, and a light receiving sensor 50054. The endoscope 5001 converges light onto the light receiving sensor 50054 via a connected mirror 5003 to generate a pixel signal, and outputs the pixel signal to the CCU 5039 via a transmission system. The mirror 5003 is an insertion part that includes an objective lens at its distal end and guides light from a connected light source device 5043 into the body of the patient 5071. The mirror 5003 can be, for example, a rigid mirror for a rigid endoscope or a flexible mirror for a flexible endoscope. The mirror 5003 can be a direct-viewing mirror or an oblique-viewing mirror. The pixel signal only needs to be a signal based on the signal output from the pixels, such as a raw (RAW) signal or an image signal. The transmission system connecting the endoscope 5001 to the CCU 5039 may include a memory, which may store parameters related to the endoscope 5001 and the CCU 5039. The memory may be located at the connection point of the transmission system or on the cable. For example, the transmission system's memory may store parameters of the endoscope 5001 before shipment or parameters that change upon power-up, and the operation of the endoscope may be modified based on parameters read from the memory. A set of cameras and the transmission system may be referred to as an endoscope. The light receiving sensor 50054 is a sensor for converting received light into pixel signals, such as a complementary metal-oxide-semiconductor (CMOS) imaging sensor. The light receiving sensor 50054 is preferably an imaging sensor with a Bayer array capable of color imaging. The light receiving sensor 50054 is preferably a camera sensor having a number of pixels corresponding to a resolution such as 4K (3840 horizontal pixels × 2160 vertical pixels), 8K (7680 horizontal pixels × 4320 vertical pixels), or square 4K (3840 or more horizontal pixels × 3840 or more vertical pixels). The light receiving sensor 50054 can be a single sensor chip or multiple sensor chips. For example, a prism can be configured to separate the incident light into predetermined bands, and these bands can be imaged using different light receiving sensors. Multiple light receiving sensors can be configured for stereoscopic viewing. The light receiving sensor 50054 can be a sensor with a chip structure including arithmetic processing circuitry for image processing, or it can be a sensor for time-of-flight (ToF). The transmission system is, for example, a fiber optic cable system or a wireless transmission system. Wireless transmission only needs to be able to transmit pixel signals generated by endoscope 5001, and for example, endoscope 5001 can be wirelessly connected to CCU 5039, or endoscope 5001 can be connected to CCU 5039 via a base station in the operating room.At this point, the endoscope 5001 can not only send pixel signals, but also simultaneously send information related to the pixel signals (e.g., pixel signal processing priority and / or synchronization signals). In the endoscope, the endoscope can be integrated with a camera, and a light-receiving sensor can be located at the distal end of the endoscope.

[0044] Camera Control Unit (CCU) CCU 5039 is a control device for unified control of endoscope 5001 and light source device 5043 connected to CCU 5039, and for example, as Figure 17 The diagram shows an information processing device including a Field Programmable Gate Array (FPGA) 50391, a Central Processing Unit (CPU) 50392, a Random Access Memory (RAM) 50393, a Read-Only Memory (ROM) 50394, a Graphics Processing Unit (GPU) 50395, and an Interface / F (I / F) 50396. The CCU 5039 can uniformly control the display device 5041, recording device 5053, and output device 5055 connected to the CCU 5039. The CCU 5039 controls, for example, the illumination timing, illumination intensity, and type of illumination light source of the light source device 5043. The CCU 5039 also performs image processing such as developing processing (e.g., demosaicing) and correction processing on the pixel signals output from the endoscope 5001, and outputs the processed image signals (e.g., images) to external devices such as the display device 5041. The CCU 5039 also sends control signals to the endoscope 5001 to control the drive of the endoscope 5001. The control signal is information about the imaging conditions, such as the magnification or focal length of the camera unit. The CCU 5039 may have the function of downconverting the image and may be configured to simultaneously output a high-resolution (e.g., 4K) image to the display device 5041 and a low-resolution (e.g., high-resolution (HD)) image to the recording device 5053.

[0045] The CCU 5039 can be connected to external devices (such as recording devices, display devices, output devices, and support devices) via an IP converter that converts signals to a predetermined communication protocol (such as Internet Protocol (IP)). The connection between the IP converter and the external device can be established using a wired network, or partially or entirely using a wireless network. For example, the IP converter on the CCU 5039 side can have wireless communication capabilities and can transmit received images to an IP switch or output-side IP converter via a wireless communication network such as 5G or 6G.

[0046] [Light source device] Light source device 5043 is a device capable of emitting light with a predetermined wavelength band, and includes, for example, multiple light sources and a light source optical system for guiding the light. The light sources are, for example, xenon lamps, light-emitting diode (LED) light sources, or laser diode (LD) light sources. Light source device 5043 includes, for example, LED light sources corresponding to the three primary colors of red (R), green (G), and blue (B), and controls the output intensity and output timing of each light source to emit white light. In addition to light sources emitting ordinary light for ordinary light observation, light source device 5043 may also include light sources capable of emitting special light for special light observation. Special light is light having a predetermined wavelength band different from ordinary light used for ordinary light observation, such as near-infrared light (light with a wavelength greater than 760 nm), infrared light, blue light, or ultraviolet light. For example, ordinary light is white light or green light. In narrowband imaging as a special light observation, blue and green light are emitted alternately, thus narrowband imaging can utilize the wavelength dependence of light absorption in body tissues to image predetermined tissues, such as blood vessels in the mucosal surface, with high contrast. In fluorescence observation, a type of special light observation, excitation light is emitted to excite a reagent injected into body tissue, and the fluorescence emitted by the body tissue or the reagent used as a marker is received to obtain a fluorescence image. Therefore, fluorescence observation allows the surgeon to easily view body tissues that are difficult to view using ordinary light. For example, in fluorescence observation using infrared light, infrared light with an excitation band is emitted to a reagent such as indocyanine green (ICG) injected into body tissue, and the fluorescence from the reagent is received. This allows fluorescence observation to easily view the structure of body tissues and affected areas. In fluorescence observation, reagents that emit red-band fluorescence when excited by special light in the blue band (such as 5-aminolevulinic acid (5-ALA)) can be used. The type of illumination light of the light source device 5043 is set by controlling the CCU 5039. The CCU 5039 may have a mode for controlling the light source device 5043 and the endoscope 5001 to alternately perform ordinary light observation and special light observation. Preferably, information based on the pixel signal obtained through special light observation is superimposed on the pixel signal obtained through ordinary light observation. Specialized optical observation can include infrared observation for viewing the inner surface of organs and multispectral observation using hyperspectral spectroscopy. Furthermore, photodynamic therapy can be combined with these methods.

[0047] [Recording device] Recording device 5053 is an apparatus for recording pixel signals (e.g., images) acquired from CCU 5039, such as a recorder. Recording device 5053 records the images acquired from CCU 5039 onto a hard disk drive (HDD), ultra-density disk (SDD), and / or optical disk. Recording device 5053 can be connected to a network within the hospital to enable access from equipment outside the operating room. Recording device 5053 may have down-conversion or up-conversion capabilities.

[0048] [Display device] Display device 5041 is a device capable of displaying images, such as a display monitor. Display device 5041 displays a display image based on pixel signals acquired from CCU 5039. Display device 5041 may include a camera and a microphone for use as an input device for command input via gaze recognition, voice recognition, and gestures.

[0049] [Output Device] Output device 5055 is a device for outputting information acquired from CCU 5039, such as a printer. Output device 5055 prints a printed image on paper, for example, based on pixel signals acquired from CCU 5039.

[0050] [Supporting Device] The support device 5027 is an articulated arm comprising: a base 5029 including an arm control device 5045, an arm portion 5031 extending from the base 5029, and a retaining portion 5032 mounted at the distal end of the arm portion 5031. The arm control device 5045 includes a processor such as a CPU and operates according to a predetermined computer program to control the drive of the arm portion 5031. The support device 5027 uses the arm control device 5045 to control parameters including, for example, the length of the link 5035 constituting the arm portion 5031 and the rotation angle and torque of the joint 5033, in order to control, for example, the position and orientation of the endoscope 5001 held by the retaining portion 5032. This control can change the position or orientation of the endoscope 5001 to a desired position or orientation, enabling insertion of the endoscope 5003 into the patient 5071 and allowing for changes in the area of ​​observation within the body. The support device 5027 serves as an endoscopic support arm for supporting the endoscope 5001 during surgery. Therefore, the support device 5027 can function as an assistant to an endoscopist in holding the endoscope 5001. The support device 5027 can also be a device for holding the microscope apparatus 5301, which will be described later, and can be referred to as a medical support arm. The support device 5027 can be controlled by an arm control device 5045 using an autonomous control method, or it can be controlled using a control method in which the arm control device 5045 performs control based on user input. The control method can be, for example, a master-slave method, in which the support device 5027, acting as a slave device (replication device), is controlled based on the movement of the master device (master controller), which is a patient cart, and the master device is an operator console at the user's hand. The support device 5027 can also be remotely controlled from outside the operating room.

[0051] Examples of endoscope systems 5000 to which the technology according to this disclosure can be applied have been described above. For example, the technology according to this disclosure can be applied to microscope systems.

[0052] [Microscope System] Figure 18 This is a figure illustrating an example of a schematic construction of a microsurgical system to which the technology according to this disclosure can be applied. In the following description, the same components as the endoscope system 5000 will be indicated by the same reference numerals and their descriptions will not be repeated.

[0053] Figure 18 The illustration schematically depicts surgeon 5067 performing surgery on patient 5071 on bed 5069 using a microsurgical system 5300. For simplicity, Figure 18 Instead of showing the trolley 5037 in the components of the microsurgical system 5300, a simplified view is shown of the microscope assembly 5301 instead of the endoscope 5001. The microscope assembly 5301 may refer to the microscope 5303 located at the distal end of the link 5035, or it may refer to the overall construction including the microscope 5303 and the support device 5027.

[0054] like Figure 18 As shown, during surgery, the microsurgical system 5300 displays magnified images of the surgical site taken by the microscope device 5301 on a display device 5041 installed in the operating room. The display device 5041 is positioned facing the surgeon 5067, who, while observing the state of the surgical site using the images displayed on the display device 5041, performs various procedures on the surgical site, such as resection of the affected area. The microsurgical system is used in, for example, ophthalmic and neurosurgical procedures.

[0055] Various examples of endoscope system 5000 and microsurgical system 5300 to which the technology according to this disclosure can be applied have been described above. Systems to which the technology according to this disclosure can be applied are not limited to such examples. For example, a support device 5027 may support other observation devices or other surgical instruments at its distal end, instead of endoscope 5001 or microscope 5303. Examples of other observation devices include forceps, tweezers, pneumoperitoneum tubes for pneumoperitoneum, and energy therapy devices for cutting tissue by cauterization or sealing blood vessels. By using a support device to support the aforementioned observation devices or surgical instruments, their position can be more stably fixed, and the workload on medical personnel can be reduced compared to manually supporting the observation devices or surgical instruments. The technology according to this disclosure can also be applied to support devices for components other than microscopes.

[0056] The technology according to this disclosure can be suitably applied to the light receiving sensor in the above-described structure. By applying the technology according to this disclosure to the light receiving sensor, clear images of the surgical site can be obtained, enabling safer and more reliable surgery.

[0057] Note that this technology can also have the following configurations. (1) A light detection device, comprising: Semiconductor substrate; Multiple photoelectric conversion units are formed in a two-dimensional array on the semiconductor substrate; and An inter-pixel isolation structure is formed in the region between the photoelectric conversion units on the semiconductor substrate, wherein... The inter-pixel isolation structure includes a first inter-pixel isolation structure that is part of the effective pixel region and a second inter-pixel isolation structure that is part of the light-shielding pixel region, wherein the light-shielding pixel region surrounds the periphery of the effective pixel region. A first conductor is arranged in the first pixel isolation structure. A second conductor is arranged in the second inter-pixel isolation structure. The second conductor is electrically connected to the first conductor and is subjected to a negative bias voltage. The first conductor and the second conductor are formed using different conductive materials. (2) The optical detection device according to (1) above further includes: A light-shielding metal is disposed on the first surface of the semiconductor substrate, which serves as the light-receiving surface, and covers the first surface of the semiconductor substrate in the light-shielding pixel region, wherein... The first conductor and the second conductor are electrically connected to each other via the light-shielding metal, and the negative bias voltage is applied to the second conductor from the second surface side. (3) According to the optical detection device described in (2) above, wherein The first conductor is formed of a conductive material with a lower light absorption rate than the second conductor. (4) According to the optical detection device described in (3) above, wherein The first conductor is made of ITO, and the second conductor is made of doped polycrystalline silicon. (5) According to the optical detection device described in (3) or (4) above, wherein The first inter-pixel isolation structure and the first conductor are formed from the first surface to the middle between the first and second surfaces, the second surface being the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface. (6) According to the optical detection device described in (5) above, wherein The first conductor is continuously arranged in the first inter-pixel isolation structure and in the region along the portion between the photoelectric conversion units on the first surface of the semiconductor substrate in the effective pixel region. The portion located on the first surface is electrically connected at its end on the light-shielding pixel region side in contact with the end of the light-shielding metal on the effective pixel region side. The end of the second conductor on the first surface side is electrically connected in such a way that it contacts the opposite surface of the light-shielding metal that is opposite to the first surface. (7) According to the optical detection device described in (2) above, wherein The first conductor is formed of a conductive material with a higher light absorption rate than the second conductor. (8) According to the optical detection device described in (7) above, wherein The first conductor is made of doped polycrystalline silicon, and The material of the second conductor is tungsten. (9) According to the optical detection device described in (7) or (8) above, wherein The first inter-pixel isolation structure and the first conductor are formed from the first surface to the middle between the first and second surfaces, the second surface being the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface. (10) According to the optical detection device described in (9) above, wherein The light-shielding metal covers the entire first surface of the semiconductor substrate in the light-shielding pixel region and the portion of the first surface of the semiconductor substrate in the effective pixel region along the area between the photoelectric conversion units. The ends of the first conductor and the second conductor on the first surface side are electrically connected in such a way that they contact the opposing surface of the light-shielding metal that is opposite to the first surface. (11) According to the optical detection device described in (1) above, wherein The first inter-pixel isolation structure and the first conductor are formed from a first surface of the semiconductor substrate, which serves as a light-receiving surface, to the middle between the first surface and the second surface, where the second surface is the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface. The first conductor is continuously arranged in the first inter-pixel isolation structure, in the region along the portion between the photoelectric conversion units on the first surface of the semiconductor substrate serving as a light-receiving surface in the effective pixel region, and on the entire first surface of the semiconductor substrate in the light-shielding pixel region. The end of the second conductor on the first surface side is electrically connected in such a way that it contacts the opposing surface of the first conductor that is opposite to the first surface. The negative bias voltage is applied to the second conductor from the second surface side. (12) According to the optical detection device described in (11) above, wherein The first conductor is formed of a conductive material with a lower light absorption rate than the second conductor. (13) According to the optical detection device described in (12) above, wherein The material of the first conductor is ITO, and The material of the second conductor is tungsten. (14) An electronic device includes a light detection device, the light detection device comprising: Semiconductor substrate; Multiple photoelectric conversion units are formed in a two-dimensional array on the semiconductor substrate; and An inter-pixel isolation structure is formed in the region between the photoelectric conversion units on the semiconductor substrate, wherein... The inter-pixel isolation structure includes a first inter-pixel isolation structure that is part of the effective pixel region and a second inter-pixel isolation structure that is part of the light-shielding pixel region, wherein the light-shielding pixel region surrounds the periphery of the effective pixel region. A first conductor is arranged in the first pixel isolation structure. A second conductor is arranged in the second inter-pixel isolation structure. The second conductor is electrically connected to the first conductor and is subjected to a negative bias voltage. The first conductor and the second conductor are formed using different conductive materials. List of reference numerals

[0058] 1. Solid-state camera device 2-pixel area 3 Vertical drive circuit 4-column signal processing circuits 5. Horizontal drive circuit 6 Output Circuit 7. Control Circuit 8 pixels 9-pixel driver wiring 10 Vertical signal lines 11 Horizontal signal line 12 effective pixel area 13 Light-blocking pixel areas 14 Semiconductor substrate 15 Insulators 16 First Conductor 17 Insulating film 18, 19 Light-shielding metal 20 wiring layers 21-pixel isolation structure 22 First pixel isolation structure 23 Second pixel isolation structure 24. Trench 25 Second conductor 26. Trench 27 Insulators 28 Contact Department 29. Resist Mask 30, 31 convex part

Claims

1. A light detection device, comprising: Semiconductor substrate; Multiple photoelectric conversion units are formed on the semiconductor substrate in a two-dimensional array. and An inter-pixel isolation structure is formed in the region between the photoelectric conversion units on the semiconductor substrate, wherein... The inter-pixel isolation structure includes a first inter-pixel isolation structure that is part of the effective pixel region and a second inter-pixel isolation structure that is part of the light-shielding pixel region, wherein the light-shielding pixel region surrounds the periphery of the effective pixel region. A first conductor is arranged in the first pixel isolation structure. A second conductor is arranged in the second inter-pixel isolation structure. The second conductor is electrically connected to the first conductor and is subjected to a negative bias voltage. The first conductor and the second conductor are formed using different conductive materials.

2. The optical detection device according to claim 1, further comprising: A light-shielding metal is disposed on the first surface of the semiconductor substrate, which serves as the light-receiving surface, and covers the first surface of the semiconductor substrate in the light-shielding pixel region, wherein... The first conductor and the second conductor are electrically connected to each other via the light-shielding metal.

3. The optical detection device according to claim 2, wherein... The first conductor is formed of a conductive material with a lower light absorption rate than the second conductor.

4. The optical detection device according to claim 3, wherein... The first conductor is made of ITO, and the second conductor is made of doped polycrystalline silicon.

5. The optical detection device according to claim 3, wherein... The first inter-pixel isolation structure and the first conductor are formed from the first surface to the middle between the first and second surfaces, the second surface being the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface.

6. The optical detection device according to claim 5, wherein... The first conductor is continuously arranged in the first inter-pixel isolation structure and in the region along the portion between the photoelectric conversion units on the first surface of the semiconductor substrate in the effective pixel region. The portion located on the first surface is electrically connected at its end on the light-shielding pixel region side in contact with the end of the light-shielding metal on the effective pixel region side. The end of the second conductor on the first surface side is electrically connected in such a way that it contacts the opposing surface of the light-shielding metal that is opposite to the first surface, and The negative bias voltage is applied to the second conductor from the second surface side.

7. The optical detection device according to claim 2, wherein... The first conductor is formed of a conductive material with a higher light absorption rate than the second conductor.

8. The optical detection device according to claim 7, wherein The first conductor is made of doped polycrystalline silicon, and The material of the second conductor is tungsten.

9. The optical detection device according to claim 7, wherein... The first inter-pixel isolation structure and the first conductor are formed from the first surface to the middle between the first and second surfaces, the second surface being the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface.

10. The optical detection device according to claim 9, wherein... The light-shielding metal covers the entire first surface of the semiconductor substrate in the light-shielding pixel region and the portion of the first surface of the semiconductor substrate in the effective pixel region along the distance between the photoelectric conversion units. The ends of the first conductor and the second conductor on the first surface side are electrically connected in such a way that they contact the opposing surface of the light-shielding metal opposite to the first surface. The negative bias voltage is applied to the second conductor from the second surface side.

11. The optical detection device according to claim 1, wherein... The first inter-pixel isolation structure and the first conductor are formed from a first surface of the semiconductor substrate, which serves as a light-receiving surface, to the middle between the first surface and the second surface, where the second surface is the surface opposite to the first surface. The second inter-pixel isolation structure and the second conductor are formed to extend through the semiconductor substrate from the first surface to the second surface. The first conductor is continuously arranged in the first inter-pixel isolation structure, in the region along the portion between the photoelectric conversion units on the first surface of the semiconductor substrate serving as the light-receiving surface in the effective pixel region, and on the entire first surface of the semiconductor substrate in the light-shielding pixel region. The end of the second conductor on the first surface side is electrically connected in such a way that it contacts the opposing surface of the first conductor that is opposite to the first surface. The negative bias voltage is applied to the second conductor from the second surface side.

12. The optical detection device according to claim 11, wherein... The first conductor is formed of a conductive material with a lower light absorption rate than the second conductor.

13. The optical detection device according to claim 12, wherein... The material of the first conductor is ITO, and The material of the second conductor is tungsten.

14. An electronic device comprising a light detection device, the light detection device comprising: Semiconductor substrate; Multiple photoelectric conversion units are formed on the semiconductor substrate in a two-dimensional array. and An inter-pixel isolation structure is formed in the region between the photoelectric conversion units on the semiconductor substrate, wherein... The inter-pixel isolation structure includes a first inter-pixel isolation structure that is part of the effective pixel region and a second inter-pixel isolation structure that is part of the light-shielding pixel region, wherein the light-shielding pixel region surrounds the periphery of the effective pixel region. A first conductor is arranged in the first pixel isolation structure. A second conductor is arranged in the second inter-pixel isolation structure. The second conductor is electrically connected to the first conductor and is subjected to a negative bias voltage. The first conductor and the second conductor are formed using different conductive materials.

Images