Light detection device

Abstract

The present disclosure relates to a light detection device that makes it possible to further reduce dark current. A light detection device according to the present invention comprises a semiconductor layer that has a light reception surface, a plurality of pixels that are provided to the semiconductor layer and have a photoelectric conversion region that makes light that enters the light reception surface undergo a photoelectric conversion, first trenches that are provided between adjacent pixels and open to at least the light reception surface side, and a transparent electrode that is formed from a light-transmitting transparent oxide semiconductor and covers the light reception surface and side walls of the first trenches. The present invention can be applied, for example, to light detection devices.

Description

Photodetector

[0001] The present disclosure relates to a light detection device.

[0002] An imaging device is known that includes a pixel separation electrode and an intra-pixel separation electrode made of a transparent material (see, for example, Patent Document 1). The pixel separation electrode is disposed in a pixel separation section, and the intra-pixel separation electrode is disposed in an intra-pixel separation section. In this imaging device, a negative first bias voltage is applied to the pixel separation electrode, and a negative second bias voltage is applied to the intra-pixel separation electrode, thereby forming a charge accumulation region in which holes are accumulated near the interface of the semiconductor substrate that contacts the pixel separation section and the intra-pixel separation section, thereby reducing dark current.

[0003] Japanese Patent Application Laid-Open No. 2022-148841

[0004] Further reduction of dark current is desired.

[0005] The present disclosure has been made in view of the above circumstances, and has an object to provide a photodetector capable of further reducing dark current.

[0006] A photodetector according to one aspect of the present technology includes a semiconductor layer having a light-receiving surface, a plurality of pixels provided in the semiconductor layer and performing photoelectric conversion on light incident on the light-receiving surface, a first trench disposed between one of the plurality of pixels and the other of the pixels, the first trench being open at least toward the light-receiving surface, and a transparent electrode made of a transparent oxide semiconductor that transmits the light, the transparent electrode covering the light-receiving surface and a sidewall of the first trench.

[0007] With this, since not only the sidewalls of the first trench but also the light-receiving surface (field portion) of the pixel are covered with a transparent electrode, it is possible to apply a negative voltage (negative bias) not only to the sidewalls of the first trench but also to the field portion. This makes it possible to accumulate holes near the interface of the semiconductor layer not only on the sidewalls but also over a wider range, including the field portion. The holes accumulated over this wider range make it possible to block the movement of charges (electrons) from the interface state over a wider range. This enables further reduction of dark current.

[0008] 1 is a diagram illustrating a configuration example of an imaging device according to a first embodiment to which the present technology is applied. FIG. 1 is a cross-sectional view illustrating a configuration example of a pixel region, which is a part of the imaging device according to the first embodiment. FIG. 2 is a cross-sectional view illustrating an enlarged configuration example of an inter-pixel isolation section, which is a part of the imaging device according to the first embodiment. FIG. 3 is a cross-sectional view illustrating an enlarged configuration example of a region where a transparent electrode and a first OPB layer are in contact with each other, and the vicinity thereof, which is a part of the imaging device according to the first embodiment. FIG. 4 is a cross-sectional view illustrating a method for manufacturing a pixel region of an imaging device in order of processes. FIG. 5 is a cross-sectional view illustrating a method for manufacturing a pixel region of an imaging device in order of processes. FIG. 6 is a cross-sectional view illustrating a method for manufacturing a pixel region of an imaging device in order of processes. FIG. 7 is a cross-sectional view illustrating a method for manufacturing a pixel region of an imaging device in order of processes. FIG. 8 is a cross-sectional view illustrating a method for manufacturing a pixel region of an imaging device in order of processes. 10A and 10B are cross-sectional views showing a method of manufacturing an inter-pixel isolation portion having a gap in order of process steps; 10B are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10C are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10D are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10E are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10F are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10H are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10H are cross-sectional views showing a method of manufacturing a pixel region of an imaging device in order of process steps; 10H are cross-sectional views showing a configuration example of an inter-pixel isolation portion according to a third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment; 10H are cross-sectional views showing another configuration example of an inter-pixel isolation portion according to the third embodiment;FIG. 10 is a cross-sectional view showing a configuration example of an inter-pixel isolation portion according to a fifth embodiment. FIG. 11 is a diagram for explaining the manufacture of the inter-pixel isolation portion according to the fifth embodiment. FIG. 12 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the fifth embodiment. FIG. 13 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the fifth embodiment. FIG. 14 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the fifth embodiment. FIG. 15 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the fifth embodiment. FIG. 16 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the fifth embodiment. FIG. 17 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the sixth embodiment. FIG. 18 is a diagram for explaining the manufacture of the inter-pixel isolation portion according to the sixth embodiment. FIG. 19 is a cross-sectional view showing an example of a configuration of an inter-pixel isolation portion according to the seventh embodiment. FIG. 19 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the seventh embodiment. FIG. 19 is a cross-sectional view showing another configuration example of an inter-pixel isolation portion according to the seventh embodiment. 13A and 13B are plan views showing an example of the configuration of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14A is a view for explaining the manufacture of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14B is a view for explaining the manufacture of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14C is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14D is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14E is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the eighth embodiment; FIG. 14F is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14G is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14H is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14H is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment;13A and 13B are cross-sectional views showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14A is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14B is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14C is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14D is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the ninth embodiment; FIG. 14E is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the tenth embodiment; FIG. 14F is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the tenth embodiment; FIG. 14G is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the tenth embodiment; FIG. 14H is a cross-sectional view showing another example of the configuration of an inter-pixel isolation portion according to the tenth embodiment; 11. A plan view showing a configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 2. A cross-sectional view showing a configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 3. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 4. A plan view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 5. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 6. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 7. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 8. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 9. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment. 10. A cross-sectional view showing another configuration example of an inter-pixel isolation portion according to an eleventh embodiment.12. A cross-sectional view showing another example of the configuration of an inter-pixel separation unit according to the twelfth embodiment ... diagram for explaining voltage application to an inter-pixel separation unit according to the twelfth embodiment. A diagram showing an example of a schematic configuration of an endoscopic surgery system. A block diagram showing an example of the functional configuration of a camera head and a CCU. A block diagram showing an example of a schematic configuration of a vehicle control system. An explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to in the following description, identical or similar parts are designated by identical or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios.

[0010] The definitions of directions such as up and down in the following description are merely for the convenience of explanation and do not limit the technical idea of ​​the present disclosure. For example, if an object is rotated 90 degrees and observed, up and down are converted to left and right and read as such, and if an object is rotated 180 degrees and observed, up and down are obviously read as reversed.

[0011] <First Embodiment> (Overall Configuration) Fig. 1 is a diagram showing an example configuration of an image pickup device 100 (an example of a "photodetector" of the present disclosure) according to a first embodiment of the present disclosure. The image pickup device 100 shown in Fig. 1 includes a substrate 111 made of silicon, a pixel region 113 having a plurality of pixels 112 arranged on the substrate 111, and a peripheral circuit unit. The peripheral circuit unit includes a vertical drive circuit 114, a column signal processing circuit 115, a horizontal drive circuit 116, an output circuit 117, and a control circuit 118.

[0012] The pixel region 113 has a plurality of pixels 112 arranged regularly in a two-dimensional array. The pixel region 113 has a pixel section that receives incident light, amplifies signal charges generated by photoelectric conversion, and reads them out to a column signal processing circuit 115, and a peripheral section that includes an optical black (hereinafter, OPB) for outputting optical black that serves as a reference for the black level. The peripheral section that includes the OPB is provided adjacent to the pixel section, such as on the periphery of the pixel section.

[0013] Each pixel 112 is composed of a photoelectric conversion element (not shown), such as a photodiode, and multiple pixel transistors (so-called MOS transistors). A plurality of pixels 112 are regularly arranged in a two-dimensional array on the substrate 111. The multiple pixel transistors can be composed of three transistors: a transfer transistor, a reset transistor, and an amplification transistor. The multiple pixel transistors can also be composed of four transistors by adding a selection transistor to the above three transistors. The pixel 112 can also have a shared pixel structure. The shared pixel structure is composed of multiple photodiodes, multiple transfer transistors, one shared floating diffusion, and each shared pixel transistor.

[0014] Based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock, the control circuit 118 generates clock signals and control signals that serve as references for the operations of the vertical drive circuit 114, the column signal processing circuit 115, and the horizontal drive circuit 116. The control circuit 118 controls the vertical drive circuit 114, the column signal processing circuit 115, and the horizontal drive circuit 116 using the clock signals and control signals.

[0015] The vertical drive circuit 114 is configured by, for example, a shift register, and sequentially selects and scans the pixels 112 in the vertical direction on a row-by-row basis. The vertical drive circuit 114 supplies pixel signals based on signal charges generated in accordance with the amount of light received by the photoelectric conversion elements of the pixels 112 to the column signal processing circuit 115 via vertical signal lines 119.

[0016] The column signal processing circuit 115 is arranged, for example, for each column of pixels 112. The column signal processing circuit 115 performs signal processing such as noise removal and signal amplification on signals output from one row of pixels 112 for each pixel column using a signal from the OPB unit. A horizontal selection switch (not shown) is provided between the output stage of the column signal processing circuit 115 and the horizontal signal line 120.

[0017] The horizontal drive circuit 116 is configured by, for example, a shift register. The horizontal drive circuit 116 sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits 115 in turn, and causes each column signal processing circuit 115 to output a pixel signal to a horizontal signal line 120.

[0018] The output circuit 117 processes pixel signals sequentially supplied from each column signal processing circuit 115 via a horizontal signal line 120 and outputs the processed signals to an external device (not shown).

[0019] The output circuit 117 processes and outputs signals sequentially supplied from each of the column signal processing circuits 115 via the horizontal signal line 120. For example, the output circuit 117 may perform only buffering in some cases, or may perform black level adjustment, column variation correction, various types of digital signal processing, and the like.

[0020] (Configuration Example of Pixel Region) Next, details of the imaging device 100 will be described with reference to FIGS. 2 to 4. FIG. 2 is a cross-sectional view showing a configuration example of the pixel region 113, which is a part of the imaging device 100 according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing an enlarged configuration example of the inter-pixel isolation section 13, which is a part of the imaging device 100 according to the first embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing an enlarged configuration example of the region where the transparent electrode 24 and the first OPB layer 161 (an example of a "conductor" in the present disclosure) contact each other and the vicinity thereof, which is a part of the imaging device 100 according to the first embodiment of the present disclosure.

[0021] 2 , the imaging device 100 is, for example, a back-illuminated solid-state imaging device, and includes a substrate 111 (an example of a "semiconductor layer" in the present disclosure), an interlayer insulating film 130, and a wiring layer 140 provided on a front surface 111a (a lower surface in FIG. 2 ) side of the substrate 111. The imaging device 100 also includes a fixed charge film 20, insulating films 22 and 32, a transparent electrode 24, an insulating cap film 26, a sidewall layer 30, a color filter CF, an on-chip lens OCL, a barrier metal layer 150, a first OPB layer 161, and a second OPB layer 162 provided on a back surface 111b (an upper surface in FIG. 2 ; an example of a "light-receiving surface" in the present disclosure) side of the substrate 111.

[0022] The substrate 111 is made of, for example, silicon. The substrate 111 has a pixel section 1 and a peripheral section 2 arranged around the pixel section 1. The pixel section 1 and the peripheral section 2 are arranged adjacent to each other. Note that a first OPB layer 161 and a second OPB layer 162 are arranged in the peripheral section 2 to provide light shielding, and therefore the peripheral section 2 may also be referred to as an OPB section or a light-shielding section.

[0023] The pixel section 1 has a plurality of pixels 112 arranged in a two-dimensional matrix (see FIG. 1 ). Each of the pixels 112 includes a photoelectric conversion region (i.e., a photodiode) 11 and a plurality of pixel transistors (not shown). The photoelectric conversion region 11 is, for example, a photodiode, which generates and accumulates signal charges corresponding to the amount of incident light received. The pixel transistor has, for example, a source / drain region provided on the surface 111 a side of the substrate 111 and a gate electrode provided on the surface 111 a of the substrate 111 via a gate insulating film.

[0024] The pixel section 1 is also provided with an inter-pixel isolation section 13 that electrically isolates adjacent pixels 112, and an intra-pixel isolation section 15 that isolates the photoelectric conversion region 11 into a plurality of regions within each pixel 112. For example, the intra-pixel isolation section 15 isolates the photoelectric conversion region 11 into a first photoelectric conversion region 11A and a second photoelectric conversion region 11B.

[0025] As shown in FIG. 3 , the inter-pixel isolation portion 13 is composed of a first trench H1 provided in the pixel portion 1, and a fixed charge film 20, an insulating film 22, and a transparent electrode 24 provided in the first trench H1. As shown in FIG. 2 , the first trench H1 of the inter-pixel isolation portion 13 penetrates, for example, between the front surface 111a and the back surface 111b of the substrate 111. Note that, in the embodiment of the present disclosure, the configuration of the inter-pixel isolation portion 13 is not limited thereto. The first trench H1 of the inter-pixel isolation portion 13 only needs to open to the back surface 111b side of the substrate 111. The first trench H1 may be provided from the back surface 111b of the substrate 111 to a midpoint between the back surface 111b and the front surface 111a (i.e., a midpoint in the depth direction of the substrate 111).

[0026] 2, the intra-pixel isolation portion 15 is composed of a second trench H2 provided in the pixel portion 1, and a fixed charge film 20, an insulating film 22, and a transparent electrode 24 provided in the second trench H2. As shown in FIG. 2, the second trench H2 of the intra-pixel isolation portion 15 penetrates between the front surface 111a and the back surface 111b of the substrate 111. The intra-pixel isolation portion 15 has the same structure as the inter-pixel isolation portion 13 shown in FIG. 3, for example. Replacing the reference numeral 13 with the reference numeral 15 and the reference numeral H1 with the reference numeral H2 in FIG. 3 results in a diagram showing an example of the configuration of the intra-pixel isolation portion 15.

[0027] 2 and 3. The second trench H2 of the intra-pixel isolation portion 15 only needs to be open to the rear surface 111b side of the substrate 111. The second trench H2 may be provided from the rear surface 111b of the substrate 111 to a midpoint between the rear surface 111b and the front surface 111a (i.e., a midpoint in the depth direction of the substrate 111).

[0028] Furthermore, the intra-pixel isolation portion 15 may be provided with a gap (overflow path) for allowing charges to flow from one of the first photoelectric conversion region 11A and the second photoelectric conversion region 11B to the other.

[0029] In the following description, the imaging device 100 including the inter-pixel isolation unit 13 shown in FIG. 3 is referred to as the imaging device 100a according to the first embodiment.

[0030] The interlayer insulating film 130 is provided continuously over the entire pixel region 113, including the pixel portion 1 and the peripheral portion 2, on the surface 111a side of the substrate 111. The interlayer insulating film 130 is made of, for example, a silicon oxide film or a laminated film of a silicon oxide film and a silicon nitride film.

[0031] The interlayer insulating film 130 includes, for example, a first insulating film 131, a second insulating film 132, a third insulating film 133, and a fourth insulating film 134. As an example, the first insulating film 131 is a silicon nitride (SiN) film formed by CVD using a Si source gas and an ammonia gas. The second insulating film 132 is a SiH ４The third insulating film 133 is a silicon oxide film (SiO) formed by CVD using a Si source gas such as tetraethoxysilane (TEOS). The fourth insulating film 134 is a silicon oxide film (SiO) formed by CVD using a SiH ４ The silicon oxide (SiO) film is formed by CVD using a Si source gas such as silicon dioxide.

[0032] 4, a first insulating film 131, a second insulating film 132, and a third insulating film 133 are alternately stacked to form an interlayer insulating film 130. The first insulating film 131, the second insulating film 132, and the third insulating film 133 may be stacked in any order. The fourth insulating film 134 is located between the substrate 111 and the wiring 142. A via V1 is formed in the fourth insulating film 134, with the wiring 142 of the wiring layer 140 serving as its bottom surface.

[0033] In the embodiments of the present disclosure, the compositions and manufacturing methods of the first insulating film 131, the second insulating film 132, the third insulating film 133, and the fourth insulating film 134 are merely examples and are not limited to these. Furthermore, the types of insulating films constituting the interlayer insulating film 130 are not limited to those described above, and the interlayer insulating film 130 may include a fifth insulating film (not shown) in addition to the first insulating film 131, the second insulating film 132, the third insulating film 133, and the fourth insulating film 134. Furthermore, the interlayer insulating film 130 may include the first insulating film 131 and the second insulating film 132, but may not include the third insulating film 133. In the embodiments of the present disclosure, the configuration of the interlayer insulating film 130 is arbitrary.

[0034] The wiring layer 140 has a plurality of wirings 141 stacked via an interlayer insulating film 130. While FIG. 2 shows an aspect in which the wiring layer 140 is disposed in the peripheral portion 2, the wiring layer 140 is provided not only in the peripheral portion 2 but also in the pixel portion 1. In the pixel portion 1, the pixel transistor of each pixel 112 is driven via the wirings 141 of the wiring layer 140. Furthermore, signal charges generated in the photoelectric conversion region 11 of each pixel 112 are output via the wirings 141 of the wiring layer 140. The wirings 141 are made of, for example, aluminum (Al), an Al alloy containing Al as a main component, copper (Cu), or a Cu alloy containing Cu as a main component.

[0035] The fixed charge film 20 is provided continuously on the sidewalls (side surfaces) of the first trench H1, the sidewalls (side surfaces) of the second trench H2, and the back surface 111b (top surface in FIG. 2 ) of the substrate 111. In this specification, the back surface 111b of the substrate 111 may be referred to as a field portion. The fixed charge film 20 continuously covers the sidewalls and field portions of the first trench H1 and the second trench H2.

[0036] The fixed charge film 20 can pin charges (holes) in a P-type layer (not shown) facing the sidewall of the first trench H1, thereby further strengthening the electric field at the PN junction between the P-type layer and the N-type layer. This makes it easier to retain charges generated in the photoelectric conversion region 11, contributing to an increase in the saturation charge quantity (Qe) of the photoelectric conversion region 11 (i.e., the photodiode). The fixed charge film 20 is, for example, an aluminum oxide (AlO) film. The fixed charge film 20 is not limited to AlO, and may also be a silicon oxide (SiO) film, a silicon nitride (SiN) film, or a hafnium oxide (HfO) film.

[0037] The insulating film 22 is provided continuously on the side walls of the first trench H1 and the second trench H2 and on the field portion via the fixed charge film 20 .

[0038] The transparent electrode 24 is provided continuously on each sidewall of the first trench H1 and the second trench H2 and on the field portion via the fixed charge film 20 and the insulating film 22. The transparent electrode 24 is provided continuously from the rear surface 111b side of the substrate 111 into the first trench H1 and the second trench H2, and covers the light-receiving surface of the pixel 112 and the sidewall of the first trench H1 and the sidewall of the second trench H2.

[0039] The transparent electrode 24 is made of a transparent oxide semiconductor that transmits light (e.g., visible light) detected by the imaging device 100. The transparent oxide semiconductor is, for example, a single layer film or a multilayer film including one or more of InO, IGZO, ITO, IZO, ZnO, SnO, and CdO.

[0040] The insulating cap film 26 is provided on the rear surface 111b side of the substrate 111, and covers the transparent electrode 24. The cap film 26 is made of, for example, one or more of a silicon oxide film (SiO) and a silicon nitride film (SiN).

[0041] The sidewall layer 30 is provided in the pixel portion 1, but not in the peripheral portion 2. In the pixel portion 1, the sidewall layer 30 is disposed above the inter-pixel isolation portion 13. The sidewall layer 30 is disposed between each filter component of the color filter CF (for example, a green filter component (G), a red filter component (R), and a blue filter component (B) described below). The sidewall layer 30 is made of, for example, polysilicon.

[0042] The insulating film 32 is provided continuously in the pixel portion 1 and the peripheral portion 2, and covers the sidewall layer 30 in the pixel portion 1 and the first OPB layer 161 in the peripheral portion 2. The insulating film 32 prevents contact between the sidewall layer 30 and the color filter CF. The insulating film 32 is, for example, a silicon oxide film.

[0043] The color filter CF is provided in the pixel portion 1 of the substrate 111. The color filter CF is disposed above each pixel 112 via a fixed charge film 20, an insulating film 22, a transparent electrode 24, an insulating cap film 26, etc.

[0044] The color filter CF has a plurality of filter components, for example, a first filter component, a second filter component, and a third filter component for each pixel 112. As an example, the first filter component, the second filter component, and the third filter component are a green filter component (G), a red filter component (R), and a blue filter component (B), respectively. The first filter component, the second filter component, and the third filter component are not limited to these, and may be any color filter component. Furthermore, at least one of the first filter component, the second filter component, and the third filter component may be a filter component other than a color filter component, such as a transparent resin that transmits visible light or an ND filter formed by adding a carbon black pigment to a transparent resin, which attenuates visible light.

[0045] An on-chip lens OCL is provided on the color filter CF. The on-chip lens OCL is formed of an organic material such as a resin. Light incident from the rear surface 111b side of the substrate 111 is condensed by the on-chip lens OCL and enters the color filter CF. Light of a desired wavelength is transmitted through the color filter CF, and the transmitted light enters the photoelectric conversion region 11 in the substrate 111.

[0046] A through via TV is provided in the peripheral portion 2 of the substrate 111, penetrating between the rear surface 111b and the front surface 111a of the substrate 111. Also, a via V1 is provided in the interlayer insulating film 130 in the peripheral portion 2, communicating with the through via TV.

[0047] The first OPB layer 161 is embedded in the through via TV and the via V1 from the back surface 111b side of the substrate 111 via the barrier metal layer 150. Furthermore, a wiring 142 of the wiring layer 140 is disposed at the bottom (lower portion in FIG. 2 ) of the via V1. The wiring 142 is made of, for example, polysilicon doped with conductive impurities. The wiring 142 is fixed to, for example, a reference potential (for example, ground potential; 0 V). The surface (upper surface in FIG. 2 ) of the wiring 142 is covered with the barrier metal layer 150. The first OPB layer 161 is connected to the wiring 142 covered with the barrier metal layer 150 through the through via TV and the via V1.

[0048] In the peripheral portion 2, a contact hole H3 is provided in the cap film 26, with the transparent electrode 24 at its bottom. As shown in FIG. 4 , the transparent electrode 24 is covered with a barrier metal layer 150 at the bottom of the contact hole H3. The first OPB layer 161 is embedded in the contact hole H3 from the rear surface 111b side of the substrate 111 via the barrier metal layer 150, and is connected to the wiring 142 covered with the barrier metal layer 150. In the imaging device 100, a negative bias voltage can be applied to the transparent electrode 24 via the wiring 142 and the first OPB layer 161.

[0049] 4 , the transparent electrode 24 may have a first region 171 and a second region 172 having a higher impurity concentration than the first region 171. The first OPB layer 161 may be connected to the second region 172 having a higher impurity concentration via a barrier metal layer 150. This makes it possible to further reduce the contact resistance between the transparent electrode 24 and the first OPB layer 161.

[0050] 2 , in the peripheral portion 2, a contact hole H4 having a bottom in the substrate 111 is provided in the cap film 26, the transparent electrode 24, the insulating film 22, and the fixed charge film 20. At the bottom of the contact hole H4, the substrate 111 is covered with a barrier metal layer 150.

[0051] The second OPB layer 162 is embedded in the contact hole H4 from the rear surface 111b side of the substrate 111 via the barrier metal layer 150, and is connected to the substrate 111 covered with the barrier metal layer 150. This allows the substrate 111 to be fixed to an arbitrary potential via the second OPB layer 162. The arbitrary potential may be, for example, a reference potential (for example, ground potential; 0 V).

[0052] <Manufacturing Method> A manufacturing method of the imaging device 100 will be described. The imaging device 100 is manufactured using various types of equipment, such as a film formation apparatus (including, for example, a plasma CVD (Chemical Vapor Deposition) apparatus, a MOCVD (Metal Organic CVD) apparatus, an ALD (Atomic Layer Deposition) apparatus, a PVD (Physical Vapor Deposition) apparatus, and a thermal oxidation apparatus), an exposure apparatus, an etching apparatus, an ion implantation apparatus, and a CMP (Chemical Mechanical Polishing) apparatus. Hereinafter, these apparatuses will be collectively referred to as manufacturing apparatuses. The pixel region 113 of the imaging device 100 can be manufactured by the manufacturing method described below.

[0053] 5 to 15 are cross-sectional views showing a method for manufacturing the pixel region 113 of the image pickup device 100a according to the first embodiment in the order of steps. Note that the manufacturing method described with reference to FIGS. 5 to 15 is not limited to the manufacturing method for the image pickup device 100a according to the first embodiment, but can also be applied as appropriate to the image pickup device 100 according to the second embodiment described below. Here, the description will continue as a method for manufacturing an image pickup device.

[0054] 5 , the manufacturing equipment deposits a fixed charge film 20, an insulating film 22, and a transparent electrode 24 in this order on the back surface 111b of the substrate 111 in which the first trench H1 and the second trench H2 are formed, thereby filling the first trench H1 and the second trench H2. For example, an AlO film is deposited as the fixed charge film 20, a SiO film is deposited as the insulating film 22, and an InO film is deposited as the transparent electrode 24. The methods for depositing the fixed charge film 20, the insulating film 22, and the transparent electrode 24 are not particularly limited, but an ALD method is one example. As a result, an inter-pixel isolation portion 13 and an intra-pixel isolation portion 15 are formed in the substrate 111.

[0055] Next, as shown in FIG. 6 , the manufacturing equipment forms a resist pattern RP1 on the back surface 111b of the substrate 111 on which the transparent electrode 24 has been formed. The resist pattern RP1 has a shape that opens above the area where the through-via TV (see FIG. 2 ) will be formed and covers the other areas. Then, using the resist pattern RP1 as a mask, the manufacturing equipment sequentially dry-etches the transparent electrode 24, the insulating film 22, and the fixed charge film 20 to expose the back surface 111b of the substrate 111. In this dry etching, the back surface 111b of the substrate 111 is over-etched.

[0056] 7, the manufacturing equipment wet-etches the substrate 111 using the resist pattern RP1 as a mask to form a through-via TV that penetrates the substrate 111 in the thickness direction. In the through-via TV forming step, the fourth insulating film 134 functions as an etching stopper.

[0057] Next, as shown in FIG. 8, the manufacturing equipment removes the resist pattern RP1 from the rear surface 111b of the substrate 111.

[0058] 9, the manufacturing equipment deposits an insulating cap film 26 on the rear surface 111b of the substrate 111. As a result, the side walls (side surfaces) of the through-via TV are also covered with the cap film 26.

[0059] 10, the manufacturing equipment forms a resist pattern RP2 on the back surface 111b of the substrate 111 on which the cap film 26 has been formed. The resist pattern RP2 has a shape that opens above the through-via TV and covers the other areas. The upper part of the cap film 26 that covers the sidewall of the through-via TV is also covered with the resist pattern RP2.

[0060] Next, the manufacturing equipment uses the resist pattern RP2 as a mask to sequentially etch the cap film 26, the first insulating film 131, and the fourth insulating film 134. In this etching, the wiring 142 of the wiring layer 140 functions as an etching stopper. As a result, a via V1 communicating with the through via TV is formed. After the via V1 is formed, the manufacturing equipment removes the resist pattern RP2.

[0061] 11, the manufacturing equipment forms a resist pattern RP3 on the rear surface 111b side of the substrate 111. The resist pattern RP3 has a shape that opens above the region where the contact hole H3 (see FIGS. 2 and 4) is to be formed and covers the other regions.

[0062] Next, the manufacturing equipment uses the resist pattern RP3 as a mask to ion-implant boron or hydrogen into the transparent electrode 24 through the cap film 26. This forms a second region 172 in the transparent electrode 24 that has a higher impurity concentration than other regions (i.e., the first region 171). Next, the manufacturing equipment uses the resist pattern RP3 as a mask to etch the cap film 26, forming a contact hole H3 whose bottom surface is the second region 172 of the transparent electrode 24. Thereafter, as shown in FIG. 12 , the manufacturing equipment removes the resist pattern RP3.

[0063] After removing the resist pattern RP3, the manufacturing equipment forms a resist pattern (not shown) on the back surface 111b of the substrate 111, opening above the region that will contact the second OPB layer 162 (see FIG. 2) and covering the other regions. Then, using this resist pattern (not shown) as a mask, the manufacturing equipment sequentially etches the cap film 26, transparent electrode 24, insulating film 22, and fixed charge film 20 to expose the back surface 111b of the substrate 111. In this etching process, the back surface 111b of the substrate 111 may be overetched. As a result, a contact hole H4 with the substrate 111 as its bottom surface is formed, as shown in FIG. After the contact hole H4 is formed, the resist pattern (not shown) is removed.

[0064] 13, the manufacturing equipment sequentially deposits a barrier metal layer 150 and an OPB layer 160 on the rear surface 111b of the substrate 111 to fill the via V1, the through-via TV, and the contact holes H3 and H4. The barrier metal layer 150 is, for example, titanium nitride (TiN) and is deposited by a PVD method such as sputtering or an MOCVD method. The barrier metal layer 150 may also be TiN deposited by combining the PVD method and the MOCVD method.

[0065] The OPB layer 160 is made of, for example, tungsten (W) and is formed by a PVD method such as sputtering or a CVD method. The OPB layer 160 may be W formed by a combination of the PVD method and the CVD method.

[0066] Next, the manufacturing equipment forms a resist pattern (not shown) on the back surface 111b of the substrate 111, covering the regions where the first OPB layer 161 and the second OPB layer 162 (see FIG. 2) will be formed and opening the upper portions of the other regions. Then, using this resist pattern (not shown) as a mask, the manufacturing equipment sequentially dry-etches the OPB layer 160 and the barrier metal layer 150. As a result, as shown in FIG. 14, the first OPB layer 161 and the second OPB layer 162 electrically isolated from the first OPB layer 161 are formed from the OPB layer 160. After the first OPB layer 161 and the second OPB layer 162 are formed, the resist pattern (not shown) is removed.

[0067] Next, the manufacturing equipment applies heat treatment to the entire substrate on which the first OPB layer 161 and the second OPB layer 162 are formed, to reduce the resistance of the transparent electrode 24. This heat treatment is performed using, for example, hydrogen (H ２ ) under a gas atmosphere.

[0068] 15, the manufacturing equipment forms a sidewall layer 30 on the rear surface 111b of the substrate 111. Next, the manufacturing equipment forms an insulating film 32 to cover the sidewall layer 30 and the surfaces of the first OPB layer 161 and the second OPB layer 162. Thereafter, the manufacturing equipment forms a color filter CF (see FIG. 2) and an on-chip lens OCL (see FIG. 2). Through the above steps, the pixel region 113 shown in FIG. 2 is completed.

[0069] Advantages of the First Embodiment As described above, the imaging device 100a according to the first embodiment of the present disclosure includes the substrate 111 having a back surface 111b serving as a light-receiving surface, a plurality of pixels 112 provided on the substrate 111 and performing photoelectric conversion on light incident on the light-receiving surface, a first trench H1 disposed between adjacent pixels 112 among the plurality of pixels 112 and opening at least toward the light-receiving surface, and a transparent electrode 24 made of a light-transmitting transparent oxide semiconductor (e.g., InO) that covers the light-receiving surface and a sidewall of the first trench H1. For example, a negative voltage is applied to the transparent electrode 24.

[0070] With this, not only the sidewalls of the first trench H1 but also the light-receiving surface (field portion) of the pixel 112 are covered with the transparent electrode 24, so it is possible to apply a negative voltage (negative bias) not only to the sidewalls of the first trench H1 but also to the field portion. This makes it possible to accumulate holes near the interface with the substrate 111 over a wider range, including not only the sidewalls but also the field portion. The holes accumulated over this wider range make it possible to block the movement of charges (electrons) from the interface state over a wider range. This makes it possible to further reduce dark current.

[0071] The imaging device 100a further includes a second trench H2 that is disposed between the adjacent first and second photoelectric conversion regions 11A and 11B in each pixel 112 and that opens at least toward the light-receiving surface of the substrate 111. The transparent electrode 24 covers the sidewalls of the second trench H2 in addition to the first trench H1 and the field portion.

[0072] With this, the sidewall of the second trench H2 is also covered with the transparent electrode 24, and it becomes possible to apply a negative voltage (negative bias) to the sidewall of the second trench H2 as well. This makes it possible to accumulate holes in the vicinity of the interface with the substrate 111 over an even wider range, thereby enabling a further reduction in dark current.

[0073] The imaging device 100a further includes an insulating cap film 26 that is provided on the light-receiving surface side of the substrate 111 and covers the transparent electrode 24. With this, in a state where the transparent electrode 24 is covered with the cap film 26, hydrogen (H ２ ) atmosphere, and the transparent electrode 24 can be ２ This can prevent the transparent electrode 24 from being exposed to the atmosphere, thereby suppressing deterioration of the film quality of the transparent electrode 24.

[0074] The transparent electrode 24 is preferably made of a material with a higher refractive index than the cap film 26. For example, the transparent electrode 24 is made of InO and the cap film 26 is made of SiO, and the transparent electrode 24 has a higher refractive index than the cap film 26. This difference in refractive index allows the transparent electrode 24 to function as an anti-reflection film. Since it is possible to prevent the amount of light incident on the pixel 112 through the cap film 26 and the transparent electrode 24 from being reduced due to reflection, it is possible to prevent a reduction in the saturation charge (Qe) of the pixel 121. It is possible to achieve both the effect of reducing dark current and the effect of preventing a reduction in Qe.

[0075] The transparent electrode 24 has a first region 171 and a second region 172 having a higher impurity concentration than the first region 171. As a result, in the transparent electrode 24, the second region 172 has a lower resistance than the first region 171. This achieves local resistance control of the transparent electrode 24. The first OPB layer 161 comes into contact with this low-resistance second region 172, thereby reducing the contact resistance between the transparent electrode 24 and the first OPB layer 161.

[0076] The imaging device 100a further includes a fixed charge film 20 provided between the transparent electrode 24 and the substrate 111. Like the transparent electrode 24, the fixed charge film 20 also covers not only the sidewalls of the first trench H1 and the second trench H2 but also the field portion. The fixed charge film 20 can pin holes, thereby further strengthening the electric field at the PN junction portion (not shown) of the photoelectric conversion region 11. This makes it easier to retain charges generated in the photoelectric conversion region 11, contributing to an increase in Qe.

[0077] Here, we have explained the effects on the imaging device 100a in the first embodiment, but these effects can also be obtained in the imaging devices 100 of the second and subsequent embodiments described below, in the same way as the imaging device 100a in the first embodiment.

[0078] Second Embodiment Fig. 16 is a diagram showing an example cross-sectional configuration of an imaging device 100b according to a second embodiment of the present disclosure. The imaging device 100b is configured to have an inter-pixel isolation portion 13 as shown in Fig. 16. As shown in Fig. 16, in the inter-pixel isolation portion 13, the inside of the first trench H1 is not completely filled with the transparent electrode 24, and a gap AG may be present.

[0079] The transparent electrode 24 transmits light but absorbs a small amount of light. However, as shown in Figure 16, the presence of the gap AG in the inter-pixel separation portion 13 makes it possible to reduce the amount of light absorbed by the transparent electrode 24 in the inter-pixel separation portion 13. This makes it possible to increase the amount of photoelectric conversion in the photoelectric conversion region 11 adjacent to the inter-pixel separation portion 13, thereby improving the saturation charge quantity (Qe).

[0080] As with the inter-pixel isolation portion 13, in the intra-pixel isolation portion 15, the inside of the second trench H2 is not completely filled with the transparent electrode 24, and a gap AG may be present. This makes it possible to increase the amount of photoelectric conversion in the first photoelectric conversion region 11A and the second photoelectric conversion region 11B adjacent to the intra-pixel isolation portion 15, thereby improving Qe. In FIG. 16, replacing reference numeral 13 with reference numeral 15 and reference numeral H1 with reference numeral H2 results in a diagram showing a modified example of the intra-pixel isolation portion 15.

[0081] 17A and 17B are cross-sectional views showing a manufacturing method of an image pickup device 100b having an inter-pixel isolation portion 13 with an air gap AG in the order of steps. In step ST1 of Fig. 17, the manufacturing equipment forms a thin film of a transparent electrode 24A around the first trench H1 by, for example, an ALD method. The transparent electrode 24A is part of the transparent electrode 24 shown in Fig. 16 and is made of, for example, InO.

[0082] Next, the manufacturing equipment forms an insulating cap film 26 to fill the first trench H1. Next, in step ST2 of FIG. 17, the manufacturing equipment applies heat treatment to the entire substrate including the transparent electrode 24A to reduce the resistance of the transparent electrode 24A. This heat treatment is performed using, for example, hydrogen (H ２ ) under a gas atmosphere.

[0083] Next, in step ST3 of Fig. 17, the manufacturing equipment removes the cap film 26. Thereafter, in step ST4 of Fig. 17, the manufacturing equipment deposits a transparent electrode 24B in the field portion of the substrate 111, for example, by PVD, to cover the top of the first trench H1. Here, the transparent electrode 24B is deposited thickly so that an air gap AG remains in the first trench H1. The transparent electrode 24B is another part of the transparent electrode 24 shown in Fig. 16 and is made of, for example, InO. Through the above steps, the inter-pixel isolation portion 13 having the air gap AG is completed.

[0084] In this manufacturing method, the intra-pixel isolation portion 15 is also formed to have a gap AG, in addition to the inter-pixel isolation portion 13. In Figure 17, if the reference numeral 13 is replaced with the reference numeral 15 and the reference numeral H1 is replaced with the reference numeral H2, the manufacturing method of the intra-pixel isolation portion 15 will be shown in the order of steps.

[0085] As described above, according to the second embodiment of the present disclosure, the first trench H1 and the second trench H2 are not completely filled with the transparent electrode 24, and a gap AG exists therein. This reduces light absorption in the first trench H1 and the second trench H2, thereby suppressing a decrease in the saturation charge (Qe) of the pixel 121. This makes it possible to achieve both the effect of reducing dark current and the effect of suppressing a decrease in Qe.

[0086] <Other Connections Between Transparent Electrode and Wiring> In the first embodiment described above, the transparent electrode 24 and the wiring 142 of the wiring layer 140 are connected via the first OPB layer 161 made of, for example, W. However, in the embodiments of the present disclosure, the connection between the transparent electrode 24 and the wiring 142 is not limited to this. The transparent electrode 24 may be extended into the through via TV and the via V1 and connected to the wiring 142 without going through the first OPB layer 161.

[0087] 18 to 23 are cross-sectional views showing a manufacturing method for the pixel region 113 of the imaging device 100 in the order of steps. In FIG. 18 , a resist pattern (not shown) is provided on the back surface 111b of the substrate 111, and a first trench H1, a second trench H2, and a through-via TV are formed in the substrate 111 by etching using this resist pattern. The manufacturing apparatus sequentially deposits a thin fixed charge film 20 and an insulating film 22 by, for example, ALD on the back surface 111b of the substrate 111 on which the first trench H1, the second trench H2, and the through-via TV are formed. As a result, the sidewalls (side surfaces) and bottom surfaces of the first trench H1, the second trench H2, and the through-via TV are covered with the fixed charge film 20 and the insulating film 22.

[0088] 19, the manufacturing equipment forms a resist pattern RP11 on the back surface 111b of the substrate 111 on which the insulating film 22 has been formed. The resist pattern RP11 has a shape that opens above the region where the via V1 will be formed and covers the other regions. Then, the manufacturing equipment uses the resist pattern RP11 as a mask to etch the fourth insulating film 134, thereby forming the via V1 whose bottom surface is the wiring 142. After the via V1 is formed, the manufacturing equipment removes the resist pattern RP11.

[0089] 20 , the manufacturing equipment deposits a transparent electrode 24 on the back surface 111b of the substrate 111 on which the via V1 is formed, filling the first trench H1, the second trench H2, the through via TV, and the via V1. The transparent electrode 24 is connected to the wiring 142 of the wiring layer 140 through the through via TV and the via V1.

[0090] Next, the manufacturing equipment forms an insulating cap film 26A on the transparent electrode 24. The cap film 26A is a part of the insulating cap film 26. In this manufacturing method, a cap film 26B is formed as another part of the cap film 26 in the step of FIG. 22 described later.

[0091] Next, the manufacturing equipment forms a resist pattern (not shown) on the back surface 111b of the substrate 111, opening above a region that will be in contact with the second OPB layer 162 (see FIG. 2) and covering the other regions. Then, using this resist pattern (not shown) as a mask, the manufacturing equipment sequentially etches the cap film 26A, the transparent electrode 24, the insulating film 22, and the fixed charge film 20 to expose the back surface 111b of the substrate 111. In this etching process, the back surface 111b of the substrate 111 may be overetched. As a result, a contact hole H4 is formed, the bottom of which is the substrate 111, as shown in FIG. After the contact hole H4 is formed, the resist pattern (not shown) is removed.

[0092] 22, the manufacturing equipment deposits an insulating cap film 26B as another part of the cap film 26. As a result, the sidewall (side surface) of the contact hole H4 is covered with the cap film 26B, and the entire cap film 26 is made thicker.

[0093] Next, the manufacturing equipment forms a resist pattern (not shown) on the back surface 111b of the substrate 111, opening above a region that will be in contact with the second OPB layer 162 (see FIG. 2) and covering the other regions. Here, the resist pattern also covers the upper portion of the cap film 26B that covers the sidewall of the contact hole H4. Next, the manufacturing equipment uses this resist pattern (not shown) as a mask to etch the portion of the cap film 26B that covers the bottom surface of the contact hole H4, exposing the substrate 111 at the bottom surface of the contact hole H4. During this etching, the substrate 111 functions as an etching stopper. After this etching, the resist pattern (not shown) is removed.

[0094] Next, the manufacturing equipment sequentially deposits a barrier metal layer 150 and an OPB layer 160 (see FIG. 13 ) on the back surface 111b of the substrate 111 to fill the contact hole H4. As described above, the OPB layer 160 is made of, for example, tungsten (W) and is deposited by a PVD method such as sputtering or a CVD method. The barrier metal layer 150 is made of, for example, titanium nitride (TiN) and is deposited by a PVD method such as sputtering or a MOCVD method.

[0095] Next, the manufacturing equipment forms a resist pattern (not shown) on the back surface 111b of the substrate 111, which covers the region where the second OPB layer 162 (see FIG. 23) is to be formed and opens above the other regions. Then, using this resist pattern (not shown) as a mask, the manufacturing equipment sequentially dry-etches the OPB layer 160 and the barrier metal layer 150. As a result, the second OPB layer 162 is formed from the OPB layer 160, as shown in FIG. 23. After the second OPB layer 162 is formed, the resist pattern (not shown) is removed.

[0096] Next, the manufacturing equipment forms a sidewall layer 30 on the rear surface 111b of the substrate 111. Next, the manufacturing equipment forms an insulating film 32 to cover the surfaces of the sidewall layer 30 and the second OPB layer 162. Thereafter, the manufacturing equipment forms a color filter CF (see FIG. 2) and an on-chip lens OCL (see FIG. 2). Through the above steps, the pixel region 113 of the image pickup device 100 is completed.

[0097] As described above, in the imaging device 100, the transparent electrode 24 extends from the pixel section 1 to the peripheral section 2 and is connected to the wiring 142 through the through vias TV and V1 in the peripheral section 2. Even in this configuration, it is possible to accumulate holes near the interface with the substrate 111 over a wider range, including the field section, rather than just on the sidewalls of the first trench H1 and the second trench H2. The holes accumulated over this wider range make it possible to block the movement of charges (electrons) from the interface state over a wider range. This allows for a further reduction in dark current, similar to the first embodiment.

[0098] 16 and 17 may be applied. That is, the first trench H1 and the second trench H2 may not be completely filled with the transparent electrode 24, and a gap AG may be present. This allows the imaging device 100 to reduce light absorption in the first trench H1 and the second trench H2, thereby suppressing a decrease in the saturation charge (Qe) of the pixel 121. This allows for both the effect of reducing dark current and the effect of suppressing a decrease in Qe.

[0099] The manufacturing method described with reference to Figures 18 to 23 is not limited to the manufacturing method of the imaging device 100 according to the first and second embodiments, but can also be appropriately applied to the imaging device 100 according to the third embodiment described below.

[0100] 24 to 30 are diagrams showing an example of a cross-sectional configuration of an inter-pixel isolation unit 13 of an image pickup device 100c according to a third embodiment. In the image pickup device 100c according to the third embodiment shown in Fig. 24 to 30, the same parts as those in the image pickup device 100a according to the first embodiment shown in Fig. 3 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0101] The imaging device 100c according to the third embodiment shown in FIG. 24 has a configuration in which a diffusion prevention film 201 is further provided in the imaging device 100a according to the first embodiment shown in FIG.

[0102] 24, an imaging device 100c is provided with a diffusion prevention film 201 between the insulating film 22 and the transparent electrode 24. The diffusion prevention film 201 is provided to prevent metal impurities from diffusing from the transparent electrode 24 to the photoelectric conversion region 11 during, for example, heat treatment during manufacturing.

[0103] The diffusion barrier film 201 can be a film with high activation energy or a high density film made of SiN, SiCN, TiN, TaN, WN, etc. The diffusion barrier film 201 can also be configured as a film having a refractive index different from that of the silicon substrate (substrate 111).

[0104] By providing the diffusion prevention film 201 between the transparent electrode 24 and the insulating film 22, for example, metal impurities from the transparent electrode 24 made of ITO are prevented from diffusing by the diffusion prevention film 201, thereby preventing the diffusion of metal impurities into the photoelectric conversion region 11.

[0105] 25 is a diagram showing an example of the configuration of an image pickup device 100c according to the embodiment 3-2. The image pickup device 100c shown in FIG. 25 has a diffusion prevention film 201 provided between the fixed charge film 20 and the insulating film 22.

[0106] As shown in Figure 25, by providing a diffusion prevention film 201 between the fixed charge film 20 and the insulating film 22, metal impurities from the transparent electrode 24 are prevented from diffusing by the diffusion prevention film 201, and therefore, the diffusion of metal impurities into the photoelectric conversion region 11 can be suppressed.

[0107] 26 is a diagram showing an example of the configuration of an image pickup device 100c according to the embodiment 3-3. The image pickup device 100c shown in FIG. 26 has a diffusion prevention film 201 provided between the substrate 111 (photoelectric conversion region 11) and the fixed charge film 20.

[0108] As shown in Figure 26, by providing a diffusion prevention film 201 between the photoelectric conversion region 11 and the fixed charge film 20, metal impurities from the transparent electrode 24 are prevented from diffusing by the diffusion prevention film 201, and therefore, the diffusion of metal impurities into the photoelectric conversion region 11 can be suppressed.

[0109] Fig. 27 is a diagram showing a configuration example of an image pickup device 100c according to Embodiment 3-4. The image pickup devices 100c according to Embodiments 3-1 to 3-3 shown in Figs. 24, 25, and 26 have been described with examples in which the diffusion prevention film 201 is provided on the side surface inside the trench and on the light-receiving surface. As shown in Fig. 27, the diffusion prevention film 201 may also be provided on the side surface inside the trench, but not on the light-receiving surface.

[0110] The imaging device 100c in the embodiment 3-4 shown in Figure 27 is an example of a case in which the diffusion prevention film 201 is provided between the photoelectric conversion region 11 and the fixed charge film 20, just like the imaging device 100c in the embodiment 3-3 shown in Figure 26. However, as in the imaging device 100c in the embodiment 3-1 shown in Figure 24, in a configuration in which the diffusion prevention film 201 is provided between the insulating film 22 and the transparent electrode 24, the diffusion prevention film 201 may not be provided on the light-receiving surface side.

[0111] Furthermore, in a configuration in which the diffusion prevention film 201 is provided between the fixed charge film 20 and the insulating film 22, such as the imaging device 100c in the embodiment 3-2 shown in Figure 25, the diffusion prevention film 201 may not be provided on the light-receiving surface side.

[0112] The imaging devices 100c according to the third to fourth embodiments shown in FIGS. 24 to 27 may be configured without the fixed charge film 20. In the imaging devices 100c according to the third to fourth embodiments shown in FIGS.

[0113] Fig. 28 is a diagram showing an example of the configuration of an image pickup device 100c according to embodiment 3-5. The image pickup device 100c shown in Fig. 28 has the same structure as the image pickup device 100a shown in Fig. 3, but differs in that the insulating film 22 is an insulating film 22' in which predetermined ions are doped.

[0114] In Figure 28, the ion doping is indicated by arrows and white circles. The insulating film 22' of the imaging device 100c shown in Figure 28 is a film made of, for example, SiO2, and is doped with carbon, fluorine, boron, or the like. The insulating film 22' has the function of capturing metal impurities from the transparent electrode 24, which is made of, for example, ITO.

[0115] By introducing a gettering material into the insulating film 22 ′, it is possible to prevent metal impurities from the transparent electrode 24 from being captured by the insulating film 22 ′ and diffusing into the photoelectric conversion region 11 .

[0116] Fig. 29 is a diagram showing a configuration example of an imaging device 100c according to embodiment 3-6. The imaging device 100c shown in Fig. 29 has a fixed charge film 20' in which a gettering material is introduced into the fixed charge film 20. The imaging device 100c shown in Fig. 29 has a fixed charge film 20' in which a predetermined ion is doped into the fixed charge film 20 formed of, for example, AlO.

[0117] By introducing a gettering material into the fixed charge film 20 ′, it is possible to prevent metal impurities from the transparent electrode 24 from being captured by the fixed charge film 20 ′ and diffusing into the photoelectric conversion region 11 .

[0118] Fig. 30 is a diagram showing a configuration example of an imaging device 100c according to Embodiment 3-7. In the imaging devices 100c according to Embodiments 3-5 and 3-6 shown in Figs. 28 and 29, examples have been described in which C (carbon) or F (fluorine) is doped into the insulating film 22' or fixed charge film 20' provided on the side surface inside the trench and on the light-receiving surface. As shown in Fig. 30, a configuration is also possible in which doping of a predetermined ion is performed on the film provided on the side surface inside the trench, but not on the film provided on the light-receiving surface.

[0119] The imaging device 100c in the embodiment 3-7 shown in Figure 30 is an example of a case where a gettering material is introduced into the fixed charge film 20', just like the imaging device 100c in the embodiment 3-6 shown in Figure 29. However, as in the imaging device 100c in the embodiment 3-5 shown in Figure 28, in a configuration where a gettering material is introduced into the insulating film 22', the insulating film 22 provided on the light receiving surface can also be configured so that no gettering material is introduced into it.

[0120] The imaging devices 100c according to the third and seventh embodiments shown in FIGS. 28 and 30 may be configured without the fixed charge film 20. In the imaging devices 100c according to the third and seventh embodiments shown in FIGS.

[0121] It is also possible to use a configuration in which any one of the embodiments 3-1 to 3-4 shown in Figures 24 to 27 is combined with any one of the embodiments 3-5 to 3-7 shown in Figures 28 to 30. That is, it is also possible to use a configuration in which the diffusion prevention film 201 and a film containing a gettering material are stacked.

[0122] The imaging device 100c according to the third embodiment can prevent metal impurities contained in the transparent electrode 24 from diffusing into the silicon substrate (photoelectric conversion region 11) due to, for example, a thermal load, thereby suppressing the occurrence of white spots and reducing dark current. By using a material with a higher refractive index than silicon for the diffusion prevention film 201, a structure can be achieved that facilitates total reflection of incident light toward the photoelectric conversion region 11, thereby improving quantum efficiency.

[0123] <Fourth embodiment> Fig. 31 is a diagram showing an example of a cross-sectional configuration of an inter-pixel isolation unit 13 of an image pickup device 100d according to a fourth embodiment. In the image pickup device 100d according to the fourth embodiment shown in Fig. 31, the same parts as those in the image pickup device 100a according to the first embodiment shown in Fig. 3 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0124] The imaging device 100d of the fourth embodiment shown in Figure 31 differs from the imaging device 100a of the first embodiment shown in Figure 3 in that a leak prevention film 221 is provided instead of the fixed charge film 20, but other points are the same.

[0125] When a transparent electrode 24 is provided and a negative bias is applied to the transparent electrode 24, a leakage current may occur, which may combine with holes in the fixed charge film 20, resulting in a decrease in the number of holes. The imaging device 100d according to the fourth embodiment is configured to suppress the occurrence of a leakage current by including a leakage prevention film 221.

[0126] 31 , a transparent electrode 24 is filled in the center of the inter-pixel separation portion 13, and an insulating film 22 is laminated on the transparent electrode 24. A leak prevention film 221 is laminated on the insulating film 22. The leak prevention film 221 is provided between the insulating film 22 and the photoelectric conversion region 11.

[0127] The leak prevention film 221 is a film formed of a material that has high leak resistance and can reduce the EOT (Equivalent Oxide Thickness), and can be made of, for example, a material that forms a gate insulating film used in a high-k metal gate. Specifically, the leak prevention film 221 can be made of materials such as Al2O3, HfO2, ZrO, TaO, TiO2, NbO, and La2O3.

[0128] The leak prevention film 221 can be made of a material used as a capacitor material for a memory or the like, or can have a capacitor structure. For example, a stacked structure of zirconia, alumina, and zirconia (ZAZ) or a stacked structure of hafnium oxide, alumina, and hafnium oxide (HAH) can be used as the leak prevention film 221. A stacked structure of films made of materials such as ZrO, HfO, AlO, and NbO can also be used as the leak prevention film 221. The leak prevention film 221 can also have a structure in which two or more types of metal oxide films are stacked.

[0129] According to the imaging device 100 d of the fourth embodiment, the leakage current generated in the inter-pixel isolation portion 13 can be suppressed.

[0130] 32 is a diagram showing an example of a cross-sectional configuration of an inter-pixel isolation unit 13 of an image pickup device 100e according to embodiment 5-1. In the image pickup device 100e according to embodiment 5-1 shown in Fig. 32, the same components as those in the image pickup device 100b according to the second embodiment shown in Fig. 16 are designated by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0131] The imaging device 100e according to the fifth embodiment shown in Fig. 32 differs from the imaging device 100b according to the second embodiment shown in Fig. 16 in that an ion-implanted film is provided, but the other aspects are basically the same. In the following explanation, an example will be given in which there is an air gap AG and the fixed charge film 20 is a thin film, as in the imaging device 100b shown in Fig. 16. The explanation will also be given using simplified diagrams.

[0132] 16 has an air gap AG in the inter-pixel isolation portion 13, and the transparent electrode 24 formed on the side wall of the inter-pixel isolation portion 13 is provided in a thin film state. The transparent electrode 24 being formed as a thin film may result in a high resistance value. If the transparent electrode 24 is formed using an oxide semiconductor material, hydrogen may easily pass through it, making it impossible to maintain the hydrogen concentration inside the inter-pixel isolation portion 13 (trench), which may result in the generation of dark current.

[0133] The basic configuration of the imaging device 100e shown in Figure 32 is similar to that of the imaging device 100b shown in Figure 16, but the imaging device 100e shown in Figure 32 differs in that it is provided with a transparent electrode 241 that is formed in an oxygen-deficient state by ion implantation into the transparent electrode 24.

[0134] In FIG. 32 , to indicate that the transparent electrode 241 is an ion-implanted transparent electrode, ions are represented by black circles and arrows indicate that the ions are being implanted. When the transparent electrode 241 is formed using an oxide semiconductor material such as InO, IGZO, ITO, IZO, ZnO, SnO, or CdO, the oxygen in the oxide is repelled by the implanted ions, creating an oxygen deficiency. This changes the film quality of the transparent electrode 241, making it less permeable to hydrogen. By providing such a hydrogen-impermeable transparent electrode 24, the hydrogen concentration inside the trench of the pixel isolation portion 13 can be maintained.

[0135] The manufacturing method of the imaging device 100e (the portion of the inter-pixel separator 13) having the transparent electrode 241 shown in FIG. 32 will be described with reference to FIG.

[0136] In step S41, a trench is formed in the silicon substrate 111. In step S42, a fixed charge film 20 is formed on the sidewalls and bottom surface of the trench formed in the silicon substrate 111, and on the surface that will be the light-receiving surface side of the silicon substrate 111. In step S43, an insulating film 22 is formed on the fixed charge film 20.

[0137] In step S44, the transparent electrode 24 is formed on the insulating film 22. The transparent electrode 24 formed in step S44 is formed using an oxide semiconductor material such as InO, IGZO, ITO, IZO, ZnO, SnO, or CdO, as in the imaging device 100a ( FIG. 3 ) described as the first embodiment.

[0138] In step S45, ions are implanted into the transparent electrode 24. Plasma doping or tilt implantation can be used for the ion implantation. Gases used during the ion implantation include, for example, BF3, B2H6, PH3, AsH3, Ar, and Ne. By implanting ions into the transparent electrode 24, the film quality of the transparent electrode 24 is changed, and a transparent electrode 241 is formed.

[0139] By these steps, the inter-pixel isolation portion 13 of the imaging device 100e shown in FIG. 32 can be formed.

[0140] Fig. 34 is a diagram showing the configuration of an imaging device 100e according to the fifth embodiment. The imaging device 100e shown in Fig. 34 includes an insulating film 243 in which ions are implanted into the insulating film 22, resulting in an oxygen deficiency. The transparent electrode 24 is formed using an oxide semiconductor material, for example, as in the imaging device 100a (Fig. 3) described as the first embodiment, and is a film that has not been implanted with ions.

[0141] In this way, it is also possible to have a configuration including an ion-implanted insulating film 243. The imaging device 100e shown in Fig. 34 can be manufactured by forming the insulating film 22 and then implanting ions into the formed insulating film 22 in step S43 of Fig. 33.

[0142] Fig. 35 is a diagram showing the configuration of an imaging device 100e according to embodiment 5-3. The imaging device 100e shown in Fig. 35 includes a transparent electrode 241 and an insulating film 243 that are oxygen-deficient as a result of ion implantation into the transparent electrode 24 and the insulating film 22.

[0143] In this way, it is also possible to have a configuration including a transparent electrode 241 and an insulating film 243 that have been subjected to ion implantation. The imaging device 100e shown in Fig. 34 can be manufactured by forming the insulating film 22 in step S43 of Fig. 33, and then implanting ions into the formed insulating film 22, and by forming the transparent electrode 24 in step S44, and then implanting ions into the formed transparent electrode 24 (step S45).

[0144] Fig. 36 is a diagram showing the configuration of an image pickup device 100e according to embodiment 5-4. The image pickup device 100e shown in Fig. 36 has a configuration in which the insulating film 22 is removed from the configuration of the image pickup device 100e according to embodiment 5-1 shown in Fig. 32. In the image pickup device 100e shown in Fig. 36, an ion-implanted transparent electrode 241 and a fixed charge film 20 are formed in the inter-pixel isolation portion 13.

[0145] In this way, it is also possible to have a configuration including the ion-implanted transparent electrode 241, but not including the insulating film 22. The imaging device 100e shown in Fig. 35 can be manufactured by omitting the step of forming the insulating film 22 in step S43 of Fig. 33.

[0146] Fig. 37 is a diagram showing the configuration of an image pickup device 100e according to the embodiment 5-5. The image pickup device 100e shown in Fig. 37 has a configuration in which an anti-reflection film 251 is formed on the transparent electrode 241 of the image pickup device 100e according to the embodiment 5-1 shown in Fig. 32.

[0147] The imaging device 100e shown in A of Fig. 37 has a configuration in which an anti-reflection film 251 is laminated on a transparent electrode 241 formed on the light-receiving surface side (the upper surface of the silicon substrate 111 in the figure). The imaging device 100e shown in A of Fig. 37 has a configuration in which the trench of the inter-pixel separation portion 13 is not blocked by the anti-reflection film 251.

[0148] The imaging device 100e shown in B of Fig. 37 has a configuration in which an anti-reflection film 251 is laminated on a transparent electrode 241 formed on the light-receiving surface side and on an area that becomes the void AG. The imaging device 100e shown in B of Fig. 37 has a configuration in which the trench of the inter-pixel separation portion 13 is blocked with the anti-reflection film 251, and a configuration in which the void AG is provided.

[0149] The anti-reflection film 251 can be formed using, for example, TaO.

[0150] In this way, the imaging device 100e provided with the antireflection film 251 can be manufactured by forming the antireflection film 251 in a step subsequent to step S45 in FIG.

[0151] Fig. 38 is a diagram showing the configuration of an image pickup device 100e according to the embodiment 5-6. The image pickup device 100e shown in Fig. 38A has an anti-reflection film 251 formed on the transparent electrode 24 of the image pickup device 100e according to the embodiment 5-2 shown in Fig. 34, and the anti-reflection film 251 is configured not to block the trench of the inter-pixel isolation portion 13.

[0152] The imaging device 100e shown in B of Figure 38 has an anti-reflection film 251 formed on the transparent electrode 24 of the imaging device 100e in embodiment 5-2 shown in Figure 34, and the anti-reflection film 251 is configured to block the trench of the inter-pixel separation portion 13, and an air gap AG is provided.

[0153] Fig. 39 is a diagram showing the configuration of an image pickup device 100e according to embodiment 5-7. The image pickup device 100e shown in Fig. 39A has an anti-reflection film 251 formed on the transparent electrode 241 of the image pickup device 100e according to embodiment 5-3 shown in Fig. 35, and the anti-reflection film 251 is configured not to block the trench of the inter-pixel isolation portion 13.

[0154] The imaging device 100e shown in B of Figure 39 has an anti-reflection film 251 formed on the transparent electrode 241 of the imaging device 100e in embodiment 5-3 shown in Figure 35, and the anti-reflection film 251 is configured to block the trench of the inter-pixel separation portion 13, and an air gap AG is provided.

[0155] Fig. 40 is a diagram showing the configuration of an image pickup device 100e according to embodiment 5-8. The image pickup device 100e shown in Fig. 40A has an anti-reflection film 251 formed on the transparent electrode 241 of the image pickup device 100e according to embodiment 5-4 shown in Fig. 36, and the anti-reflection film 251 is configured not to block the trench of the inter-pixel isolation portion 13.

[0156] The imaging device 100e shown in B of Figure 40 has an anti-reflection film 251 formed on the transparent electrode 241 of the imaging device 100e in embodiment 5-4 shown in Figure 36, and the anti-reflection film 251 is configured to block the trench of the inter-pixel separation portion 13, and a gap AG is provided.

[0157] According to the imaging device 100e of the fifth embodiment, the resistance of the transparent electrodes 24 and 241 can be reduced, and the interface can be terminated, thereby improving the interface state.

[0158] 41 is a diagram showing an example of a cross-sectional configuration of an inter-pixel isolation unit 13 of an image pickup device 100f according to a sixth embodiment. In the image pickup device 100f according to the sixth embodiment shown in Fig. 41, the same components as those in the image pickup device 100b according to the second embodiment shown in Fig. 16 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0159] The imaging device 100f according to the sixth embodiment shown in Fig. 41 differs from the imaging device 100b according to the second embodiment shown in Fig. 16 in that a film for replenishing hydrogen is provided, but the other points are the same. In the following explanation, a case where the fixed charge film 20 is a thin film, as in the imaging device 100b shown in Fig. 16, will be taken as an example. Also, the explanation will be given using simplified diagrams.

[0160] The interface state tends to be poor on the sidewalls inside the trench of the inter-pixel isolation portion 13. By forming, for example, a SiO film as the insulating film 22 on the sidewalls inside the trench, the sidewalls are terminated to some extent by the supply of hydrogen, and the dark current is reduced, but by forming the transparent electrode 24, it becomes difficult for the supply of hydrogen from the fixed charge film 20 and insulating film 22 between the transparent electrode 24 and the photoelectric conversion region 11 to reach the sidewalls, which may increase the dark current.

[0161] The basic configuration of the imaging device 100f shown in Fig. 41 is similar to that of the imaging device 100b shown in Fig. 16, but the imaging device 100f shown in Fig. 41 is similar to the imaging device 100b shown in Fig. 16 except that a hydrogen supply film 301 is provided between the transparent electrode 24 and the insulating film 22. Note that the trench may be filled with a material such as SiO or may have no void AG.

[0162] 41 , the supply of hydrogen from the hydrogen supply film 301 to the fixed charge film 20 and the insulating film 22 is indicated by an arrow and an H. The hydrogen supply film 301 is provided between the insulating film 22 and the transparent electrode 24 formed on the side surface of the trench in the inter-pixel isolation portion 13. If the transparent electrode 24 and the insulating film 22 are also provided on the bottom surface of the trench, the hydrogen supply film 301 can also be provided between the transparent electrode 24 and the insulating film 22 on the bottom surface of the trench.

[0163] The hydrogen supply film 301 may be configured not to be provided on the light-receiving surface side (upper surface in the figure) of the photoelectric conversion region 11. The hydrogen supply film 301 may be, for example, a film containing a metal such as TiN (titanium nitride). If the hydrogen supply film 301 is a film containing a metal, it may reduce the amount of light incident on the photoelectric conversion region 11, and therefore the hydrogen supply film 301 is not provided on the light-receiving surface side. If a transparent material is used as the hydrogen supply film 301, the hydrogen supply film 301 may also be provided on the light-receiving surface side.

[0164] By providing the hydrogen supply film 301 on the transparent electrode 24 on the side surface inside the trench, it is possible to reduce dark current and color mixing between pixels, thereby improving pixel characteristics.

[0165] The manufacture of the imaging device 100f (part of the inter-pixel separation portion 13) having the transparent electrode 241 shown in Fig. 41 will be described with reference to Fig. 42. In step S61, a trench is formed in the silicon substrate 111.

[0166] In step S62, a fixed charge film 20 is formed on the sidewalls and bottom surface of the trench formed in the silicon substrate 111 and on the surface of the silicon substrate 111 that will become the light-receiving surface, and an insulating film 22 is formed on the formed fixed charge film 20. The fixed charge film 20 and the insulating film 22 can be formed by ALD film formation at 400° C. or less. In addition, to prevent the formed film from peeling off, an annealing treatment may be added after the film formation.

[0167] In step S63, the hydrogen supply film 301 is formed on the insulating film 22. The hydrogen supply film 301 can be formed, for example, by applying the MoCVD method using TiN as a material and an organometallic compound as a source gas. The organometallic compound is a compound formed by bonding a metal with a hydrocarbon group.

[0168] In step S63, film formation and treatment are alternately performed. For example, the hydrogen supply film 301 is formed by alternately performing the film formation of a TDMAT organic substance and the H2 / N2 plasma treatment a predetermined number of times.

[0169] In step S64, the transparent electrode 24 is formed. After that, the trench is filled with SiO, or a predetermined film is formed on the trench to form the gap AG.

[0170] By these steps, the inter-pixel isolation portion 13 of the imaging device 100f shown in FIG. 41 can be formed.

[0171] According to the sixth embodiment, dark current is reduced, color mixing between pixels is reduced, and pixel characteristics can be improved.

[0172] 43 is a diagram showing an example of a cross-sectional configuration of an inter-pixel isolation unit 13 of an image pickup device 100g according to an embodiment 7-1. In the image pickup device 100g according to the embodiment 7-1 shown in Fig. 43, the same components as those in the image pickup device 100a according to the first embodiment shown in Fig. 3 are designated by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0173] The imaging device 100g according to the seventh embodiment shown in Figure 43 differs from the imaging device 100a according to the first embodiment shown in Figure 3 in that a film for sealing in hydrogen is provided, but the other points are the same. In the following explanation, a case in which the fixed charge film 20 is filled in the trench, as in the imaging device 100a shown in Figure 3, will be described as an example. Also, the explanation will be given using simplified diagrams.

[0174] If the transparent electrode 24 is formed using an oxide semiconductor material, hydrogen will permeate the transparent electrode 24 and flow into the cap film 26, making it impossible to maintain the hydrogen concentration inside the inter-pixel separation portion 13 (trench), which may result in the generation of dark current.

[0175] The basic configuration of the image pickup device 100g shown in Fig. 43 is the same as that of the image pickup device 100a shown in Fig. 3, but the image pickup device 100g shown in Fig. 41 is different in that a hydrogen sealing film 321 is provided on the transparent electrode 24 provided on the light receiving surface side, and the other points are the same. Note that the 7-1 embodiment can be applied to the image pickup device 100b in the second embodiment shown in Fig. 16, and a gap AG can be formed in the inter-pixel separation portion 13.

[0176] 43 has a configuration in which a hydrogen sealing film 321 is laminated on a transparent electrode 24 formed on the entire light-receiving surface. Therefore, the hydrogen sealing film 321 is also formed on the entire light-receiving surface. The hydrogen sealing film 321 is a film that serves to seal hydrogen on the trench side so that hydrogen does not permeate from the transparent electrode 24 and through the transparent electrode 24 to the cap film 26 side.

[0177] The hydrogen sealing film 321 can be a film made of a material with high hydrogen sealing performance, such as Al2O3. The hydrogen sealing film 321 can also be a film made of a material with high amorphous properties, such as IZO or IGZO. Because the hydrogen sealing film 321 is provided on the light-receiving surface side, a transparent oxide semiconductor material is used.

[0178] For example, Al2O3 can be used as the fixed charge film 20, and Al2O3 can also be used as the hydrogen sealing film 321. The fixed charge film 20 and the hydrogen sealing film 321 may be made of the same material or different materials.

[0179] The hydrogen sealing film 321 can be configured to be provided on the light-receiving surface side in the same region as the transparent electrode 24, or can be configured to be provided in a region that covers at least the inter-pixel separation portion 13 in a planar view.

[0180] Fig. 44 is a diagram showing the configuration of an image pickup device 100g according to the embodiment 7-2. The image pickup device 100g shown in Fig. 44 differs from the image pickup device 100g according to the embodiment 7-1 shown in Fig. 43 in that an anti-reflection film 323 made of, for example, Ta2O5 is provided between the transparent electrode 24 provided on the light receiving surface side and the silicon substrate 111. The other points are the same.

[0181] Fig. 45 is a diagram showing the configuration of an image pickup device 100g according to the embodiment 7-3. The image pickup device 100g shown in Fig. 45 differs from the image pickup device 100a according to the first embodiment shown in Fig. 3 in that the transparent electrode 24 provided on the light receiving surface side is formed of a transparent electrode 325 made of an amorphous material, but other points are basically the same.

[0182] In the imaging device 100g shown in Figure 45, the transparent electrode 24 disposed vertically within the trench is formed using an oxide semiconductor material such as InO, IGZO, ITO, IZO, ZnO, SnO, or CdO. In contrast to the vertically disposed transparent electrode 24, the transparent electrode 325 disposed horizontally on the light detection surface is formed using an amorphous transparent electrode material such as IZO or IGZO. Because the amorphous transparent electrode 325 plays a role corresponding to the hydrogen sealing film 321 of the imaging device 100g in the seventh embodiment, for example, the hydrogen sealing film 321 may not be provided.

[0183] Fig. 46 is a diagram showing the configuration of an image pickup device 100g according to the embodiment 7-4. The image pickup device 100g shown in Fig. 46 differs from the image pickup device 100g according to the embodiment 7-3 shown in Fig. 45 in that an anti-reflection film 323 is provided between the light receiving surface side and the silicon substrate 111, but other points are the same.

[0184] According to the seventh embodiment, a layer with high hydrogen sealing properties is provided to prevent hydrogen desorption from inside the trench in which the transparent electrode 24 is provided, so that the amount of hydrogen inside the trench can be maintained and dark current can be reduced.

[0185] 47 is a diagram showing an example of a cross-sectional configuration of the inter-pixel isolation unit 13 of an image pickup device 100h according to embodiment 8-1. In the image pickup device 100h according to embodiment 8-1 shown in Fig. 47, the same components as those in the image pickup device 100a according to the first embodiment shown in Fig. 3 are designated by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0186] The imaging device 100h according to the embodiment 8-1 shown in Fig. 47 differs from the imaging device 100a according to the first embodiment shown in Fig. 3 in that it is provided with a high-quality oxide film formed at a high temperature, but is otherwise similar. In the following explanation, a case in which the fixed charge film 20 is filled in the trench, as in the imaging device 100a shown in Fig. 3, will be described as an example. Also, the explanation will be given using simplified diagrams.

[0187] If the transparent electrode 24 is provided and a bias is applied, the voltage resistance of the fixed charge film 20 and the insulating film 22 may become insufficient, which may cause leakage current or fluctuation in characteristics.

[0188] The basic configuration of the image pickup device 100h shown in Fig. 47 is similar to that of the image pickup device 100a shown in Fig. 3, but the image pickup device 100h shown in Fig. 47 is similar to the image pickup device 100a shown in Fig. 3 except that a high-temperature formed oxide film 341 is provided on the side surface of the trench in the inter-pixel isolation portion 13. Note that the 8-1 embodiment can be applied to the image pickup device 100b in the second embodiment shown in Fig. 16, and the air gap AH can be formed in the inter-pixel isolation portion 13.

[0189] 47 shows an image pickup device 100h having a configuration in which a high-temperature formed oxide film 341 is provided on the sidewall of the trench of the inter-pixel isolation portion 13, between the silicon substrate 111 and the fixed charge film 20. The high-temperature formed oxide film 341 is an oxide film formed at a high temperature, for example, 1000°C or higher, during formation, and has few impurities, high density, and good film quality. By providing such a film on the sidewall, a configuration can be achieved in which both interface characteristics and insulating properties (leak resistance) can be achieved.

[0190] The high-temperature formed oxide film 341 is a film formed at a high temperature using, for example, SiO. When the imaging device 100h is manufactured through the manufacturing process described below, a SiO film 343 is laminated on the fixed charge film 20 at the bottom of the trench in the inter-pixel isolation portion 13.

[0191] In the manufacturing process described below, when the high-temperature formed oxide film 341 is formed using a method that is dependent on the plane orientation, the high-temperature formed oxide film 341 has a cross-sectional configuration as shown in Fig. 48. The high-temperature formed oxide film 341 is provided so as to surround the photoelectric conversion region 11. Its thickness is not constant, and the width of the high-temperature formed oxide film 341 located on the sides (side portions) of the photoelectric conversion region 11 is formed to be wider than the width of the high-temperature formed oxide film 341 located on the corners (corner portions) of the photoelectric conversion region 11. In other words, the high-temperature formed oxide film 341 at the corners is formed to be thinner than the high-temperature formed oxide film 341 at the sides.

[0192] The manufacture of the imaging device 100g (the portion of the inter-pixel isolation portion 13) having the high-temperature formed oxide film 341 shown in FIG. 48 will be described with reference to FIG.

[0193] In step S81, trenches are formed in the silicon substrate 111. When the finally manufactured imaging device 100g is viewed, these trenches are formed so as to penetrate the silicon substrate 111. A SiN film 345 is formed on the silicon substrate 111 between the trenches.

[0194] In step S82, a high-temperature formed oxide film 341 is formed on the sidewalls and bottom surface of the trench formed in the silicon substrate 111. When the high-temperature formed oxide film 341 is formed by, for example, an ISSG (in-situ steam generation) method or a plasma oxidation method, the thickness of the high-temperature formed oxide film 341 is constant because it is not dependent on the plane orientation. When the high-temperature formed oxide film 341 is formed by, for example, a dry oxidation method, the thickness of the high-temperature formed oxide film 341 is not constant because it is dependent on the plane orientation, and is formed in a shape that is thinner at the corners, as shown in FIG.

[0195] The high-temperature-formed oxide film 341 is formed at a temperature of 1000° C. or higher in step S82. As described above, the high-temperature-formed oxide film 341 has few impurities and is a high-density film of good quality. By providing such high-temperature-formed oxide film 341 on the sidewalls of the trench, it is possible to improve the interface characteristics and the insulating properties (leak resistance).

[0196] In step S83, a dummy film 347 is formed in the trench in which the high-temperature formed oxide film 341 has been formed. The dummy film 347 is formed using a material that has a selectivity to both Si (silicon) and SiO (silicon oxide) that constitute the silicon substrate 111.

[0197] In step S84, etching back is performed to remove a part of the dummy film 347. By etching back the dummy film 347, a part of the high-temperature formed oxide film 341 is exposed.

[0198] In step S85 (FIG. 50), an SiO film 343 is formed on the etched-back dummy film 347 and the SiN film 345. In step S86, the silicon substrate 111 is turned upside down.

[0199] In step S87, the silicon substrate 111 on the upper side in the drawing is polished and thinned by, for example, CMP. In step S88, the dummy film 347 is etched and removed. By removing the dummy film 347, the high-temperature formed oxide film 341 formed on the sidewall of the trench is exposed.

[0200] In step S89 ( FIG. 51 ), the fixed charge film 20 is formed. In step S90, the insulating film 22 is formed on the formed fixed charge film 20. In step S91, the transparent electrode 241 is formed on the formed insulating film 22. The transparent electrode 24 is formed inside the trench and on the light-receiving surface side. The film formation processes in steps S89 and S90 are performed at a temperature of, for example, 400° C. or less.

[0201] In step S92, the cap film 26 is formed on the formed transparent electrode 241.

[0202] By these steps, the inter-pixel separator 13 of the imaging device 100h shown in FIG. 48 can be formed.

[0203] Fig. 52 is a diagram showing the configuration of an imaging device 100h according to the embodiment 8-2. The imaging device 100h shown in Fig. 52 has a configuration in which the fixed charge film 20 is omitted from the configuration of the imaging device 100h according to the embodiment 8-1 shown in Fig. 47. The imaging device 100h may also be configured without the fixed charge film 20.

[0204] By providing the high-temperature formed oxide film 341 on the sidewalls inside the trench, it is possible to improve the interface quality and the leakage resistance, and it is possible to deal with pinning without providing the fixed charge film 20. By adopting a configuration in which the fixed charge film 20 is not provided, it is expected that the reflectance inside the trench will be improved and color mixing will be reduced.

[0205] Fig. 53 is a diagram showing the configuration of an image pickup device 100h according to the embodiment 8-3. The image pickup device 100h shown in Fig. 53 has a configuration in which a high K film 349 is further formed on the image pickup device 100h according to the embodiment 8-1 shown in Fig. 47.

[0206] The high K film 349 is provided between the insulating film 22 and the transparent electrode 24. By providing the high K film 349, the amount of holes that flow out when a bias voltage is applied to the transparent electrode 24 can be boosted, and the generation of dark current can be further suppressed.

[0207] Fig. 54 is a diagram showing the configuration of an image pickup device 100h according to the embodiment 8-4. The image pickup device 100h shown in Fig. 54 has a configuration in which a diffusion prevention film 351 is further formed on the image pickup device 100h according to the embodiment 8-1 shown in Fig. 47.

[0208] The diffusion prevention film 351 is provided between the insulating film 22 and the transparent electrode 24. The provision of the diffusion prevention film 351 makes it possible to prevent the metal contained in the transparent electrode 24 from diffusing toward the silicon substrate 111, thereby suppressing dark current resulting from metal impurities.

[0209] Fig. 55 is a diagram showing the configuration of an imaging device 100h according to the embodiment 8-5. The imaging device 100h shown in Fig. 55 has a configuration in which the transparent electrode 24 of the imaging device 100h according to the embodiment 8-1 shown in Fig. 47 is made thinner.

[0210] The transparent electrode 24 of the image pickup device 100h shown in Fig. 55 is thinned, and the trench is filled with the same material as the cap film 26, for example, SiO. Thinning the transparent electrode 24 may result in insufficient reflectance on the light receiving surface, resulting in a decrease in quantum efficiency (Qe). To compensate for such a decrease in quantum efficiency, the image pickup device 100h shown in Fig. 55 is provided with an anti-reflection film 353.

[0211] The anti-reflection film 353 is provided between the fixed charge film 20, which is also provided on the light-receiving surface side, and the insulating film 22. The anti-reflection film 353 can be formed using, for example, TaO as its material.

[0212] According to the eighth embodiment, it is possible to improve the interface characteristics and the leakage resistance.

[0213] 56 is a diagram showing an example of a cross-sectional configuration of the inter-pixel isolation unit 13 of an image pickup device 100i according to an embodiment 9-1. In the image pickup device 100i according to the ninth embodiment, the same components as those in the image pickup device 100a according to the first embodiment shown in FIG. 3 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0214] The imaging device 100i according to the 9-1 embodiment shown in Figure 56 differs from the imaging device 100a according to the first embodiment shown in Figure 3 in that a metal film 401 is provided in the transparent electrode 24 filling the inter-pixel isolation portion 13, but is otherwise similar. In the following explanation, a case in which the fixed charge film 20 fills the trench, as in the imaging device 100a shown in Figure 3, will be described as an example. The explanation will also be given using simplified diagrams.

[0215] If the transparent electrode 24 is filled in the trench of the inter-pixel separation portion 13, there is a possibility that light will leak into adjacent pixels, causing color mixing. In addition, since a voltage is continuously applied to the transparent electrode 24, power consumption tends to increase.

[0216] The basic configuration of the imaging device 100i shown in Fig. 56 is similar to that of the imaging device 100a shown in Fig. 3, but the imaging device 100i shown in Fig. 56 is similar to the imaging device 100a shown in Fig. 3 except that a metal film 401 is provided in the trench of the inter-pixel isolation portion 13. Note that the ninth embodiment can be applied to the imaging device 100b of the second embodiment shown in Fig. 16, and a configuration can be adopted in which a metal film 401 is provided in the gap AG.

[0217] By embedding the metal film 401 in the transparent electrode 24, a structure can be created in which a voltage is applied to the metal film 401 and the transparent electrode 24, thereby reducing the resistance value and power consumption.

[0218] The metal used for the metal film 401 may be W, Al, Cu, AlCu, or an alloy containing Ag, Al, Cu, or the like. The metal film 401 shown in FIG. 56 has a structure with an air gap AG therein. The metal film 401 may have a structure with an air gap AG or may not have an air gap AG. By providing the metal film 401 in the inter-pixel separation portion 13, it is possible to prevent light from leaking into adjacent pixels and reduce color mixing.

[0219] 56 is provided with a light-shielding film 402 for preventing color mixing on the light-receiving surface side of the inter-pixel isolation portion 13. Color filters (not shown) are formed on both sides of the light-shielding film 402. The light-shielding film 402 can be made of the same metal as the metal film 401.

[0220] Fig. 57 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-2. The image pickup device 100i shown in Fig. 57 has a configuration in which a refractive layer 411 with a high refractive index is provided on the light-shielding film 402 of the image pickup device 100i according to the embodiment 9-1 shown in Fig. 56, and the light-shielding film 402 and the refractive layer 411 form a light-shielding wall. The refractive layer 411 is made of a material with a refractive index of, for example, about n to 1.2.

[0221] Fig. 58 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-3. The image pickup device 100i shown in Fig. 58 has a configuration in which an air layer 413 is provided on the light-shielding film 402 of the image pickup device 100i according to the embodiment 9-1 shown in Fig. 56, and the light-shielding film 402 and the air layer 413 form a light-shielding wall.

[0222] Fig. 59 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-4. The image pickup device 100i shown in Fig. 59 has a configuration in which a high-refractive-index material layer 415 is provided on the transparent electrode 24 provided on the entire light receiving surface of the image pickup device 100i according to the embodiment 9-1 shown in Fig. 56. The high-refractive-index material layer 415 is made of a material having a refractive index equal to that of the transparent electrode 24, or of about 2 to 2.2, for example.

[0223] Fig. 60 is a diagram showing the configuration of an imaging device 100i according to the embodiment 9-5. The imaging device 100i shown in Fig. 60 has a configuration similar to that of the imaging device 100i according to the embodiment 9-1 shown in Fig. 56, but differs in that a liner film 417 is provided at a position where the metal film 401 and the transparent electrode 24 contact each other. The liner film 417 is provided between the upper edge of the metal film 401 and the transparent electrode 24 laminated on that upper edge.

[0224] Providing the liner film 417 can improve the adhesion between the transparent electrode 24 and the metal film 401. When the transparent electrode 24 is an n-type oxide semiconductor, an ohmic contact can be achieved by using a metal having a work function smaller than that of the transparent electrode 241 as the liner film 417.

[0225] Fig. 61 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-6. In the image pickup device 100i shown in Fig. 61, the light-shielding film 402 of the image pickup device 100i according to the embodiment 9-1 shown in Fig. 56 is connected to the metal film 401 and is provided as a single metal layer in the vertical direction.

[0226] Fig. 62 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-7. In the image pickup device 100i shown in Fig. 62, the light-shielding film 402 of the image pickup device 100i according to the embodiment 9-2 shown in Fig. 57 is connected to a metal film 401 and provided as a single metal layer in the vertical direction, and a refractive layer 411 is provided on the light-shielding film 102 of the metal layer.

[0227] Fig. 63 is a diagram showing the configuration of an image pickup device 100i according to the embodiment 9-8. In the image pickup device 100i shown in Fig. 63, the refractive layer 411 of the image pickup device 100i according to the embodiment 9-2 shown in Fig. 57 penetrates the cap film 26 and the transparent electrode 24, is provided up to the metal film 401, and is connected to the metal film 401.

[0228] Fig. 64 is a diagram showing the configuration of an imaging device 100i in embodiment 9-9. The imaging device 100i shown in Fig. 64 has a configuration implemented by combining embodiment 9-4 shown in Fig. 59 and embodiment 9-6 shown in Fig. 61. The imaging device 100i shown in Fig. 64 has a configuration in which a light-shielding film 402 and a metal film 401 are connected, and a high-flexibility material layer 415 is laminated on a transparent electrode 24.

[0229] Fig. 65 is a diagram showing the configuration of an image pickup device 100i according to the 9-10th embodiment. The image pickup device 100i shown in Fig. 65 includes a light-shielding film 402 similar to the image pickup device 100i according to the 9-1st embodiment shown in Fig. 57, but differs in that the light-shielding film 402 penetrates the cap film 26 and is formed to a position that reaches into the transparent electrode 24.

[0230] 65 is configured such that a light-shielding film 402 and a metal film 401 are connected via a transparent electrode 24. A liner film 417 is formed between the light-shielding film 402 and the transparent electrode 24 and between the metal film 401 and the transparent electrode 24, respectively, to improve adhesion with the transparent electrode 24.

[0231] Fig. 66 is a diagram showing the configuration of an imaging device 100i according to embodiments 9-11. The imaging device 100i shown in Fig. 66 has the same structure as the imaging device 100i according to embodiments 9-10 shown in Fig. 65, but differs in that the light-shielding film 402 is formed up to a position where it contacts the upper surface of the transparent electrode 24. The light-shielding film 402 of the imaging device 100i shown in Fig. 66 penetrates the cap film 26, is formed up to the upper surface of the transparent electrode 24, and is connected to a metal film via the transparent electrode 24.

[0232] In the imaging device 100i shown in Figure 66, a liner film 417 is formed between the light-shielding film 402 and the transparent electrode 24, and between the metal film 401 and the transparent electrode 24, thereby improving adhesion to the transparent electrode 24.

[0233] The imaging device 100i including the metal film 401 can be manufactured by applying the manufacturing method of the imaging device 100a according to the first embodiment described with reference to Figures 5 to 15 and adding a step of forming the metal film 401. For example, after the transparent electrode 24 is formed, when the through via TV is formed in the step described with reference to Figures 6 and 7, a trench for providing the metal film 401 is formed in the transparent electrode 24 formed in the trench of the inter-pixel separation portion 13.

[0234] After the trenches are formed, the resist pattern RP1 is removed as described with reference to Fig. 8. By removing the resist pattern RP1, the transparent electrode 24 is exposed, and a trench is opened in the transparent electrode 24 that fills the inter-pixel isolation portion 13. By filling the trenches with a material that will become the metal film 401, the metal film 401 can be formed in the trenches.

[0235] According to the ninth embodiment, a bias voltage can be applied by combining the metal film 401 and the transparent electrode 24, which can reduce white spot dark current and power consumption. Also, color mixing can be reduced.

[0236] 67 is a diagram showing an example of a cross-sectional configuration of the inter-pixel isolation unit 13 of an image pickup device 100j according to an embodiment 10-1. In the image pickup device 100j according to the tenth embodiment, the same components as those in the image pickup device 100b according to the second embodiment shown in FIG. 16 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0237] The imaging device 100i according to the embodiment 10-1 shown in Fig. 67 differs from the imaging device 100b according to the second embodiment shown in Fig. 16 in that a conductive material film 501 is provided in the inter-pixel isolation portion 13, but is otherwise basically the same. In the following explanation, a case in which the transparent electrode 24 is thinned as in the imaging device 100b shown in Fig. 16 will be used as an example. The explanation will also be given using simplified diagrams.

[0238] The inter-pixel isolation 13 of the image pickup device 100j according to the embodiment 10-1 shown in Fig. 67 has a configuration in which a fixed charge film 20, an insulating film 22, and a transparent electrode 24 are laminated on the side surface of a trench in this order from the photoelectric conversion region 11 side. The inter-pixel isolation 13 of the image pickup device 100j according to the embodiment 10-1 has a configuration in which a conductive material film 501 is filled in the region that is the void AG in the image pickup device 100b shown in Fig. 16.

[0239] The imaging device 100j shown in FIG. 67 has a conductive material film 501 in which a conductive material is filled in the trench of the inter-pixel isolation portion 13 up to the light-receiving surface side.

[0240] When the transparent electrode 24 is made thinner, the cross-sectional area of ​​the transparent electrode 24 decreases, the resistance value of the transparent electrode 24 increases, and the voltage drop increases. By providing the conductive material film 501, the cross-sectional area through which current flows becomes the combined cross-sectional area of ​​the transparent electrode 24 and the conductive material film 501, thereby reducing the resistance value and making it possible to reduce the voltage drop. By providing the conductive material film 501, the amount of voltage drop in the vertical direction and in the planar direction (horizontal direction) of the trench of the inter-pixel separation portion 13 can be reduced, thereby improving the dark current characteristics.

[0241] Fig. 68 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-2. The image pickup device 100j shown in Fig. 68 is similar to the image pickup device 100j according to the embodiment 10-1 shown in Fig. 67 except that a conductive material film 501 is provided in a part of the trench.

[0242] 68A shows an image pickup device 100j according to the embodiment 10-2, in which a conductive material film 501 is provided with a predetermined thickness on the upper part (light receiving surface side) of the trench. In the region inside the trench where the conductive material film 501 is not provided, a gap AG is formed.

[0243] 68B, an imaging device 100j according to the embodiment 10-2 has a conductive material film 501 provided with a predetermined thickness in the lower part of the trench (the side opposite to the light receiving surface side). In the region inside the trench where the conductive material film 501 is not provided, an air gap AG is formed.

[0244] In the image pickup device 100j according to the embodiment 10-2 shown in Fig. 68C, a conductive material film 501 is provided with a predetermined thickness in the central region of the trench. In the region inside the trench where the conductive material film 501 is not provided, an air gap AG is formed, and in the example shown in Fig. 68C, an air gap AG is provided above and below the conductive material film 501.

[0245] 68D, an imaging device 100j according to the embodiment 10-2 has conductive material films 501 of a predetermined thickness provided on the upper and lower parts of a trench (on the light-receiving surface side and on the side opposite the light-receiving surface side). The region inside the trench between the conductive material film 501-1 provided on the upper part and the conductive material film 501-2 provided on the lower part is an air gap AG.

[0246] As shown in FIG. 68, by providing the gap AG, it is possible to reduce the absorption and reflection of light from inside the pixel, compared to the imaging device 100j according to the embodiment 10-1 shown in FIG.

[0247] Fig. 69 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-3. The image pickup device 100j shown in Fig. 69 is similar to the image pickup device 100j according to the embodiment 10-1 shown in Fig. 67 except that a conductive material film 501 is provided in a part of the trench.

[0248] In the imaging device 100j according to the embodiment 10-3 shown in A of Fig. 69, a triangular conductive material film 501 is provided on the sidewall of a trench so that its base is located at the bottom of the trench. A triangular conductive material film 501-1 is provided on one sidewall inside the trench, and a triangular conductive material film 501-2 is provided on the other sidewall, with the region where the conductive material film 501-1 and the conductive material film 501-2 are not provided being a gap AG. The gap AG is formed in a trapezoidal shape in cross section.

[0249] An imaging device 100j according to the embodiment 10-3 shown in Fig. 69B includes a conductive material film 501 formed in a shape whose cross-sectional area increases from top to bottom (the same triangular shape as shown in Fig. 69A), with the bottom being closed (quadrilateral). A gap AG is formed in the region inside the trench where the conductive material film 501 is not provided.

[0250] By providing a conductive material film 501 as shown in A and B of Figure 69, it is possible to continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0251] The imaging device 100j according to the embodiment 10-3 shown in Fig. 69C is similar to the imaging device 100j according to the embodiment 10-3 shown in Fig. 69A in that it includes the triangular conductive material film 501, but differs in that its orientation is upside down. The imaging device 100j according to the embodiment 10-3 shown in Fig. 69C has a triangular conductive material film 501 provided on the side wall of the trench with its base positioned at the top of the trench. The region between the triangular conductive material film 501-1 provided on one side wall inside the trench and the triangular conductive material film 501-2 provided on the other side wall is defined as an air gap AG. The air gap AG is trapezoidal in cross section.

[0252] The imaging device 100j according to the embodiment 10-3 shown in Fig. 69D is similar to the conductive material film 501 shown in Fig. 69B in that it includes a conductive material film 501 having the same shape as the conductive material film 501 shown in Fig. 69B, but differs in that its orientation is upside down. The imaging device 100j according to the embodiment 10-3 shown in Fig. 69D includes a conductive material film 501 formed in a shape whose cross-sectional area increases from bottom to top (the same triangular shape as the shape shown in Fig. 69C), and whose upper part is closed (rectangular). A gap AG is formed in the region inside the trench where the conductive material film 501 is not provided.

[0253] By providing a conductive material film 501 as shown in C and D of Figure 69, it is possible to partially and continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0254] Fig. 70 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-4. The image pickup device 100j shown in Fig. 70 is similar to the image pickup device 100j according to the embodiment 10-1 shown in Fig. 67 except that a conductive material film 501 is provided in a part of the trench.

[0255] The imaging device 100j according to the embodiment 10-4 shown in A of Fig. 70 includes a conductive material film 501 formed in a shape whose cross-sectional area decreases from top to bottom (the same triangular shape as the shape shown in C of Fig. 69) and whose lower portion is closed (rectangular). Triangular conductive material films 501-1 and 501-2 are provided in the upper portion of the trench, and a rectangular conductive material film 501-3 is provided in the lower portion of the trench. A gap AG is formed in the region inside the trench where the conductive material film 501 is not provided.

[0256] The imaging device 100j according to the embodiment 10-4 shown in FIG. 70B includes a conductive material film 501 whose upper and lower portions are closed, and whose upper portion has a shape whose cross-sectional area decreases from top to bottom (the same triangular shape as shown in FIG. 70A). The imaging device 100j shown in FIG. 70B has large triangular conductive material films 501-1 and 501-2 formed on the upper portion of the imaging device 100j shown in FIG. 70A. As a result of being formed larger, the conductive material films 501-1 and 501-2 on the upper side of the trench are partially overlapped. A rectangular conductive material film 501-3 is provided at the bottom of the trench. A void AG is formed in the area inside the trench where the conductive material film 501 is not provided, and the void AG is formed in a triangular shape.

[0257] The imaging device 100j according to the embodiment 10-4 shown in Fig. 70C includes a conductive material film 501 formed in a shape whose cross-sectional area decreases from top to bottom (the same triangular shape as shown in Fig. 70A) and which is closed near the center of the trench (rectangular shape). The imaging device 100j shown in Fig. 70C has the same shape as the conductive material film 501 of the imaging device 100j shown in Fig. 70A, but the upper triangular conductive material films 501-1 and 501-2 are small, and the lower rectangular conductive material film 501-3 is formed near the center of the trench. A gap AG is formed in the area inside the trench where the conductive material film 501 is not provided. The gap AG above the rectangular conductive material film 501-3 is triangular, and the gap AG below the conductive material film 501-3 is rectangular.

[0258] An imaging device 100j according to the embodiment 10-4 shown in Fig. 70D includes a conductive material film 501 formed in a shape (rectangular shape) that is closed near the center of the trench, with the top of the trench closed and the cross-sectional area decreasing from the top toward the center (the same triangular shape as shown in Fig. 70A). The imaging device 100j shown in Fig. 70D has the same shape as the conductive material film 501 of the imaging device 100j shown in Fig. 70B, but the upper conductive material films 501-1 and 501-2 are small and have shapes that partially overlap each other, and the lower rectangular conductive material film 501-3 is formed near the center of the trench. In the region inside the trench where the conductive material film 501 is not provided, a void AG is formed, and the void AG above the rectangular conductive material film 501-3 is formed in a triangular shape, while the void AG below the conductive material film 501-3 is formed in a rectangular shape.

[0259] By providing a conductive material film 501 as shown in Figure 70, it is possible to partially and continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0260] Fig. 71 is a diagram showing the configuration of an imaging device 100j according to the embodiment 10-3. In the imaging device 100j shown in Fig. 71, a conductive material film 501 is provided in a portion of the trench, and a SiO film 511 is provided in another portion. The SiO film 511 is a film containing SiO as a material. Note that although the explanation will be continued using SiO as an example, a film using another material may also be used.

[0261] 71A shows an image pickup device 100j according to the embodiment 10-3, in which a conductive material film 501 is provided with a predetermined thickness on the upper part (light receiving surface side) of the trench, and a SiO film 511 is provided in the region inside the trench where the conductive material film 501 is not provided.

[0262] 71B, an image pickup device 100j according to the embodiment 10-3 has a conductive material film 501 with a predetermined thickness provided in the lower part of the trench (the side opposite to the light receiving surface side). A SiO film 511 is provided in the region inside the trench where the conductive material film 501 is not provided.

[0263] 71C shows an image pickup device 100j according to the embodiment 10-3, in which a conductive material film 501 is provided with a predetermined thickness near the center of the trench. In the region inside the trench where the conductive material film 501 is not provided, a SiO film 511 is provided. In the example shown in FIG. 71C, the SiO film 511 is provided above and below the conductive material film 501.

[0264] 71D, an imaging device 100j according to the embodiment 10-3 has conductive material films 501-1 and 501-2 provided at predetermined thicknesses on the upper and lower parts of a trench (the light-receiving surface side and the side opposite the light-receiving surface side), respectively. A SiO film 511 is provided in the region inside the trench between the conductive material film 501-1 provided at the upper part and the conductive material film 501-2 provided at the lower part.

[0265] As shown in FIG. 71, by providing the SiO film 511, it is possible to reduce the absorption and reflection of light from inside the pixel, compared to the imaging device 100j according to the embodiment 10-1 shown in FIG.

[0266] 72 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-4. In the image pickup device 100j shown in Fig. 72, a conductive material film 501 is provided in a part of the trench, a SiO2 film 511 is provided in another part, and an air gap AG is provided in still another part.

[0267] 72A shows an image pickup device 100j according to the embodiment 10-4, in which a conductive material film 501 is provided with a predetermined thickness near the center of the trench. An SiO film 511 is provided above the conductive material film 501 inside the trench, and an air gap AG is provided below it.

[0268] 72B shows an image pickup device 100j according to the embodiment 10-4, in which a conductive material film 501 is provided with a predetermined thickness near the center of the trench. An air gap AG is provided above the conductive material film 501 inside the trench, and a SiO film 511 is provided below it.

[0269] By providing the conductive material film 501 as shown in A and B of Figure 72, it is possible to continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0270] An imaging device 100j according to the embodiment 10-4 shown in C of Fig. 72 includes a conductive material film 501 having the same shape as the conductive material film 501 according to the embodiment 10-3 shown in C of Fig. 70. A triangular void AG is provided above the conductive material film 501-3 inside the trench, and a rectangular SiO film 511 is provided below it.

[0271] An imaging device 100j according to the embodiment 10-4 shown in D of Fig. 72 includes a conductive material film 501 having the same shape as the conductive material film 501 according to the embodiment 10-3 shown in D of Fig. 70. A triangular gap AG is provided above the conductive material film 501-3 inside the trench, and a rectangular SiO film 511 is provided below it.

[0272] By providing a conductive material film 501 as shown in C and D of Figure 72, it is possible to partially and continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0273] Fig. 73 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-5. In the image pickup device 100j shown in Fig. 75, a conductive material film 501 is provided in a part of the trench, and a SiO2 film 511 and / or an air gap AG is provided in another part.

[0274] The conductive material film 501 shown in FIG. 73 has the same shape as the conductive material film 501 in FIG. 69B, but differs in that it is formed smaller in size.

[0275] The imaging device 100j according to the embodiment 10-5 shown in A of Fig. 73 includes a conductive material film 501 formed in a shape whose cross-sectional area increases from the top toward the center (the same triangular shape as shown in A of Fig. 69) and which is closed (rectangular) near the center. In the region inside the trench where the conductive material film 501 is not provided, a substantially triangular void AG is provided above the conductive material film 501, and a rectangular SiO film 511 is provided below.

[0276] The imaging device 100j according to the embodiment 10-5 shown in Fig. 73B includes a conductive material film 501 that is the same as the conductive material film 501 of the imaging device 100j shown in Fig. 73A. In the region inside the trench where the conductive material film 501 is not provided, a substantially triangular void AG is provided in the upper part of the conductive material film 501, and a rectangular void AG is provided in the lower part.

[0277] The imaging device 100j according to the embodiment 10-5 shown in Fig. 73C includes a conductive material film 501 that is the same as the conductive material film 501 of the imaging device 100j shown in Fig. 73A. In the region inside the trench where the conductive material film 501 is not provided, a triangular void AG is provided above the conductive material film 501, and a rectangular SiO film 511 is provided below it.

[0278] The imaging device 100j according to the embodiment 10-5 shown in Fig. 73D includes a conductive material film 501 that is the same as the conductive material film 501 of the imaging device 100j shown in Fig. 73A. In the region inside the trench where the conductive material film 501 is not provided, a triangular SiO film 511 is provided above the conductive material film 501, and a rectangular void AG is provided below it.

[0279] By providing the conductive material film 501 as shown in Figure 73, it is possible to partially and continuously reduce the absorption and reflection of light from inside the pixel compared to the imaging device 100j in the embodiment 10-1 shown in Figure 67.

[0280] Fig. 74 is a diagram showing the configuration of an image pickup device 100j according to the embodiment 10-6. In the image pickup device 100j shown in Fig. 76, a conductive material film 501 is provided in a part of the trench, and a SiO2 film 511 and / or an air gap AG is provided in another part.

[0281] 74A, an imaging device 100j according to the 10-6th embodiment has rectangular conductive material films 501-1 and 501-2 provided on the side walls of a trench. The region inside the trench where the conductive material film 501 is not provided is a rectangular region in the center of the trench, and an air gap AG is provided in this region.

[0282] 74B, an imaging device 100j according to the embodiment 10-6 has rectangular conductive material films 501-1 and 501-2 provided on the side walls of a trench. The region inside the trench where the conductive material film 501 is not provided is a rectangular region in the center of the trench, and this region is provided with a SiO film 511 filled with SiO.

[0283] 74C, an imaging device 100j according to the 10-6th embodiment has rectangular SiO films 511-1 and 511-2 provided on the side walls of the trench. The region inside the trench where the SiO film 511 is not provided is a rectangular region in the center of the trench, and a conductive material film 501 is provided in this region.

[0284] By providing the conductive material film 501 as shown in FIG. 74, it is possible to reduce the absorption of light from inside the pixel compared to the imaging device 100j according to the embodiment 10-1 shown in FIG.

[0285] The manufacture of the imaging device 100j (the portion of the inter-pixel separation portion 13) having the conductive material film 501 shown in FIG. 68C will be described with reference to FIGS.

[0286] In step S101, a trench is formed in a silicon substrate 111, and a fixed charge film 20, an insulating film 22, and a transparent electrode 24 are formed on the sidewalls and bottom surface of the trench and on the surface of the silicon substrate 111 that will become the light-receiving surface.

[0287] In step S102, a conductive material that will become the conductive material film 501 is filled into the trench of the inter-pixel separation portion 13, and a film of the conductive material film 501 (which will be partially removed in a later step) is formed on the transparent electrode 24 formed on the light-receiving surface side.

[0288] In step S103, a mask 531 is formed on the conductive material film 501 formed on the light-receiving surface side. In step S104, the mask 531 is processed by lithography into a mask 531 having an opening corresponding to the region of the inter-pixel isolation portion 13.

[0289] In step S105, etching is performed to form trenches in the regions opened in the mask 531. The etching is stopped midway, so that the processing is completed in a state where rectangular conductive material film 501 remains at the bottom of the trenches.

[0290] In step S106 ( FIG. 76 ), mask 531 is removed. In step S107, SiO to become SiO film 511 is filled in the trench of inter-pixel isolation portion 13 and on conductive material film 501 formed in the lower part, and SiO film 511 is also formed on conductive material film 501 remaining on the light-receiving surface side.

[0291] In step S108, the SiO film 511 and the conductive material film 501 formed on the light-receiving surface side are removed by, for example, CMP. When this step is completed, the imaging device 100j shown in FIG. 71B is manufactured.

[0292] In step S109, the SiO film 511 is removed from inside the trench of the inter-pixel isolation portion 13. When step S109 is performed, an image pickup device j shown in C of Fig. 68 is manufactured.

[0293] Although the explanation is omitted, imaging devices j other than the imaging device j exemplified here can also be manufactured by inserting necessary steps into the above-described steps as appropriate.

[0294] According to the tenth embodiment, the cross-sectional area of ​​the current path can be increased, and the amount of voltage drop can be reduced in both the vertical and horizontal directions of the trench in the pixel separation portion 13, thereby improving characteristics in the dark. By forming the conductive material film 501 using a conductive material that has lower electrical resistance than the transparent electrode 24, a configuration can be achieved that further suppresses voltage drop, making it possible to save power.

[0295] 11th Embodiment Fig. 77 is a diagram showing an example of the planar configuration of an image pickup device 100k according to an 11-1 embodiment, and Fig. 78 is a diagram showing an example of the cross-sectional configuration. In the image pickup device 100j according to the 11th embodiment, the same parts as those of the image pickup devices 100a and 100b according to the first or second embodiment shown in Fig. 3 or 16 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0296] The imaging device 100k according to the embodiment 11-1 shown in Fig. 77 differs from the imaging devices 100a and 100b according to the first or second embodiment shown in Fig. 3 or 16 in that the configuration of the inter-pixel separator 13 differs between the corner portions (hereinafter referred to as corner portions) and the side portions (hereinafter referred to as side portions) of the pixels 112, but is otherwise similar. In the following explanation, an example will be given in which the transparent electrode 24 is thinned, as in the imaging device 100b shown in Fig. 16. The explanation will also be given using simplified diagrams.

[0297] Fig. 77 is a diagram showing an example of the planar configuration of a pixel region 113 of an imaging device 100k according to the 11-1 embodiment. In the pixel region 113, pixels 112 (photoelectric conversion regions 11) are arranged in a two-dimensional array. Each photoelectric conversion region 11 is surrounded by an inter-pixel isolation portion 13. When the photoelectric conversion region 11 is formed in a rectangular shape in a plan view, the inter-pixel isolation portions 13 located at the corners of the photoelectric conversion region 11 have different configurations from the inter-pixel isolation portions 13 located at the sides of the photoelectric conversion region 11, as shown in Fig. 78.

[0298] 78A is a cross-sectional view of the inter-pixel isolation section 13 taken along line AA in FIG. 77, and FIG. 78B is a cross-sectional view of the inter-pixel isolation section 13 taken along line BB in FIG.

[0299] The inter-pixel isolation portion 13 along line A-A shown in A of Fig. 78 has the same basic configuration as the inter-pixel isolation portion 13 of the imaging device 100b according to the second embodiment shown in Fig. 16, and has a configuration in which a fixed charge film 20, an insulating film 22, and a transparent electrode 24 are laminated in this order from the photoelectric conversion region 11 side. In the inter-pixel isolation portion 13 shown in A of Fig. 78, SiO is filled in the trench, and an SiO film 611 is formed.

[0300] The inter-pixel isolation portion 13 along line B-B shown in B of Figure 78 has a configuration similar to the inter-pixel isolation portion 13 arranged on the side of the photoelectric conversion region 11 shown in A of Figure 78 in that it has a configuration in which a fixed charge film 20, an insulating film 22, and a transparent electrode 24 are laminated in this order from the photoelectric conversion region 11 side on the side surface of the trench. In the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11, a conductive material film 601 is further formed in the trench. In the imaging device 100k shown in B of Figure 78, a conductive material film 601 is provided in which a conductive material is filled in the trench of the inter-pixel isolation portion 13 up to the light-receiving surface side.

[0301] When the transparent electrode 24 is made thinner, the cross-sectional area of ​​the transparent electrode 24 decreases, the resistance value of the transparent electrode 24 increases, and the voltage drop increases. By providing the conductive material film 601 in the inter-pixel isolation portion 13 located at the corner of the photoelectric conversion region 11, the cross-sectional area through which current flows becomes the combined cross-sectional area of ​​the transparent electrode 24 and the conductive material film 601, thereby reducing the resistance value and voltage drop. By providing the conductive material film 601 in part of the inter-pixel isolation portion 13, the amount of voltage drop in the vertical direction and in the planar direction (horizontal direction) of the trench of the inter-pixel isolation portion 13 can be reduced, and dark current characteristics can be improved.

[0302] By configuring the photoelectric conversion region 11 so that the conductive material film 601 is disposed at the corners thereof but not at the sides thereof, it is possible to minimize the absorption of light within the pixel and prevent a decrease in Qe (conversion efficiency).

[0303] Figure 79 is a diagram showing the configuration of an image pickup device 100k according to the embodiment 11-2. In the image pickup device 100k shown in Figure 79, a conductive material film 601 is provided in a portion of the trench of the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11, and a SiO film 611 is provided in the other portion. The SiO film 611 is a film containing SiO as a material. Note that although the explanation will be continued using SiO as an example, a film using another material may also be used.

[0304] 79A shows an image pickup device 100k according to the embodiment 10-3, in which a conductive material film 601 is provided with a predetermined thickness on the upper part (light receiving surface side) of the trench, and a SiO film 611 is provided in the region inside the trench where the conductive material film 601 is not provided.

[0305] 79B shows an image pickup device 100k according to the embodiment 10-3, in which a conductive material film 601 is provided with a predetermined thickness in the lower part of the trench (the opposite side to the light receiving surface). A SiO film 611 is provided in the region inside the trench where the conductive material film 601 is not provided.

[0306] An imaging device 100k according to the embodiment 10-3 shown in Fig. 79C has a conductive material film 601 with a predetermined thickness near the center of the trench. An SiO film 611 is provided in the region inside the trench where the conductive material film 601 is not provided. In the example shown in Fig. 79C, the SiO film 611 is provided above and below the conductive material film 601.

[0307] 79D, an imaging device 100k according to the embodiment 10-3 has conductive material films 601-1 and 601-2 provided with a predetermined thickness in the upper and lower parts of a trench (the light-receiving surface side and the side opposite the light-receiving surface side), respectively. A SiO film 611 is provided in the region inside the trench between the conductive material film 601-1 provided in the upper part and the conductive material film 601-2 provided in the lower part.

[0308] As shown in FIG. 79, by providing the SiO film 611, it is possible to reduce the absorption of light from inside the pixel, compared to the imaging device 100k according to the embodiment 11-1 shown in FIG.

[0309] Fig. 80 is a diagram showing an example of the planar configuration of the pixel region 113 of the image pickup device 100k according to the embodiment 11-3. The example of the planar configuration of the image pickup device 100k according to the embodiment 11-3 shown in Fig. 80 is basically the same as the example of the planar configuration of the image pickup device 100k according to the embodiment 11-1 shown in Fig. 77, except that the inter-pixel separators 13 arranged on the sides of the photoelectric conversion region 11 have gaps AG.

[0310] 81A is a cross-sectional view of the inter-pixel isolation section 13 taken along line AA in FIG. 80, and FIG. 81B is a cross-sectional view of the inter-pixel isolation section 13 taken along line BB in FIG.

[0311] The inter-pixel separation portion 13 along line A-A shown in A of Figure 81 is similar to the inter-pixel separation portion 13 of the image pickup device 100k shown in Figure 78 in that it has a configuration in which the fixed charge film 20, the insulating film 22, and the transparent electrode 24 are laminated in this order from the photoelectric conversion region 11 side, but differs in that a gap AG is provided in the trench. In other words, the inter-pixel separation portion 13 along line A-A shown in A of Figure 81 has a configuration similar to the inter-pixel separation portion 13 provided in the image pickup device 100b according to the second embodiment shown in Figure 16.

[0312] The inter-pixel separator 13 along the line B--B shown in B of FIG. 81 has the same configuration as the inter-pixel separator 13 shown in B of FIG.

[0313] In this way, the inter-pixel separation portions 13 arranged on the sides of the photoelectric conversion region 11 are configured to have a gap AG, and the inter-pixel separation portions 13 arranged on the corners are configured to have a conductive material film 601, and it is also possible to configure the inter-pixel separation portions 13 surrounding the photoelectric conversion region 11 to have regions with different configurations.

[0314] Fig. 82 is a diagram showing the configuration of an image pickup device 100k according to the embodiment 11-4. The image pickup device 100k shown in Fig. 82 is similar to the image pickup device 100j according to the embodiment 11-2 shown in Fig. 79 in that a conductive material film 501 is provided in a part of the trench of the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11, and a gap AG is provided in the other part.

[0315] 82A shows an image pickup device 100k according to the embodiment 11-4, in which a conductive material film 601 is provided with a predetermined thickness on the upper part (light receiving surface side) of the trench, and an air gap AG is formed in the region inside the trench where the conductive material film 601 is not provided.

[0316] 82B, an imaging device 100k according to the embodiment 11-4 has a conductive material film 601 with a predetermined thickness provided in the lower part of the trench (the opposite side of the light receiving surface). A gap AG is formed in the region inside the trench where the conductive material film 601 is not provided.

[0317] An imaging device 100k according to the 11-4th embodiment shown in Fig. 82C has a conductive material film 601 with a predetermined thickness provided near the center of the trench. A gap AG is formed in the region inside the trench where the conductive material film 601 is not provided, and in the example shown in Fig. 82C, gaps AG are provided above and below the conductive material film 601.

[0318] 82D, an imaging device 100k according to the 11-4th embodiment has conductive material films 601-1 and 601-2 provided at predetermined thicknesses on the upper and lower parts of a trench (the light-receiving surface side and the side opposite the light-receiving surface side), respectively. The region inside the trench between the conductive material film 601-1 provided at the upper part and the conductive material film 601-2 provided at the lower part is an air gap AG.

[0319] As shown in Figure 82, by providing a gap AG, more light from inside the pixel can be reflected toward the photoelectric conversion region 11 than in the imaging device 100k of the embodiment 11-2 shown in Figure 79.

[0320] 83 is a diagram showing the configuration of an image pickup device 100k according to the embodiment 11-5. In the image pickup device 100k shown in Fig. 83, a film of a conductive material is provided in a trench of an inter-pixel isolation portion 13 arranged at a corner of a photoelectric conversion region 11.

[0321] The inter-pixel isolation portion 13 shown in Figure 83 shows the configuration of the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11, but the inter-pixel isolation portion 13 at the side of the photoelectric conversion region 11 can also be configured in combination with the inter-pixel isolation portion 13 provided with the SiO film 611 shown in A of Figure 78, or in combination with the inter-pixel isolation portion 13 provided with the gap AG shown in A of Figure 81.

[0322] The imaging device 100k according to the 11-5th embodiment shown in A of Fig. 83 has a conductive material film 621 made of a transparent material provided inside the trench. Examples of transparent materials that can be used for the conductive material film 621 include oxide semiconductor materials such as InO, IGZO, ITO, IZO, ZnO, SnO, and CdO. The transparent electrode 24 is also made of a transparent and conductive material, and therefore the transparent electrode 24 and the conductive material film 621 can be made of the same material.

[0323] 83B shows an image pickup device 100k according to the embodiment 11-5, which has a conductive material film 623 formed of an opaque material having high reflectivity inside the trench. Examples of highly reflective materials that can be used for the conductive material film 623 include metals such as Ag and Al, and alloys containing these metals.

[0324] As shown in FIG. 83, by providing a transparent or opaque conductive film, it is possible to reflect a large amount of light from inside the pixel toward the photoelectric conversion region 11 side.

[0325] Fig. 84 is a diagram showing an example of the planar configuration of the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11. Fig. 84 shows an example of the shape of the conductive material film 601. The conductive material film 601 shown in Fig. 84A is formed in a circular shape. The conductive material film 601 shown in Fig. 84B is formed in a quadrilateral (approximately square) shape.

[0326] The conductive material film 601 shown in Fig. 84C is formed in an octagonal shape. The conductive material film 601 shown in Fig. 84D is formed in an octagonal shape with straight or curved sides, and the curved sides are formed in a shape that follows the photoelectric conversion region 11. The conductive material film 601 shown in Fig. 84D is formed in an elliptical shape.

[0327] The conductive material film 601 shown in F of Fig. 84 is formed in a diamond shape. The conductive material film 601 shown in G of Fig. 84 is formed in an octagon with sides of different lengths. The conductive material film 601 shown in H of Fig. 84 is formed in an octagon with straight or curved sides, and the straight parts are shaped so that the corners contact the photoelectric conversion region 11.

[0328] Fig. 85 is a diagram showing another example of the planar configuration of the inter-pixel isolation portion 13 arranged at the corner of the photoelectric conversion region 11. Fig. 85 shows an example of the shape of a conductive material film 601'. The conductive material film 601' shown in Fig. 85A has the same shape as that shown in Fig. 84A, but differs in that it is formed hollow. The conductive material film 601' shown in Fig. 85B has the same shape as that shown in Fig. 84B, but differs in that it is formed hollow.

[0329] The conductive material film 601' shown in C of Fig. 85 has the same shape as that shown in C of Fig. 84, but differs in that it is formed hollow. The conductive material film 601' shown in D of Fig. 85 has the same shape as that shown in D of Fig. 84, but differs in that it is formed hollow. The conductive material film 601' shown in D of Fig. 85 has the same shape as that shown in D of Fig. 84, but differs in that it is formed hollow.

[0330] The conductive material film 601' shown in F of Fig. 85 has the same shape as that shown in F of Fig. 84, but differs in that it is formed hollow. The conductive material film 601' shown in G of Fig. 85 has the same shape as that shown in G of Fig. 84, but differs in that it is formed hollow. The conductive material film 601' shown in H of Fig. 85 has the same shape as that shown in H of Fig. 84, but differs in that it is formed hollow.

[0331] The manufacture of inter-pixel isolation portions 13 having conductive material films 601 at the corners of the photoelectric conversion region 11 shown in Figures 77 and 78 will be described with reference to Figures 86 and 87. Figures 86 and 87 show inter-pixel isolation portions 13 at the sides of the photoelectric conversion region 11 and inter-pixel isolation portions 13 at the corners.

[0332] In step S131, trenches are formed in the silicon substrate 111 at both the sides and corners of the photoelectric conversion region 11, and a fixed charge film 20, an insulating film 22, and a transparent electrode 24 are formed on the side walls and bottom surface of the formed trenches, and on the surface of the silicon substrate 111 that will become the light-receiving surface.

[0333] In step S132, SiO to become the SiO film 611 is filled into the trenches of the inter-pixel separation portions 13 at both the sides and corners of the photoelectric conversion region 11, and a film of the SiO film 611 (part of which is removed in a later step) is formed on the transparent electrode 24 formed on the light-receiving surface side.

[0334] In step S133, a mask 631 is formed on the SiO film 611 formed on the light-receiving surface side at both the side and corner portions of the photoelectric conversion region 11.

[0335] In step S134, the mask 631 is processed by lithography at both the sides and corners of the photoelectric conversion region 11. In step S134, the mask 631 is processed so that only the regions of the inter-pixel isolation portions 13 located at the corners of the photoelectric conversion region 11 are opened.

[0336] In step S135 ( FIG. 87 ), etching is performed on both the side and corner portions of the photoelectric conversion region 11, thereby forming trenches in the regions opened in the mask 631. In this case, trenches are formed in the inter-pixel isolation portions 13 located at the corner portions of the photoelectric conversion region 11, but trenches are not formed in the inter-pixel isolation portions 13 located at the side portions of the photoelectric conversion region 11.

[0337] In step S136, the mask 631 is removed from both the sides and corners of the photoelectric conversion region 11.

[0338] In step S137, a conductive material film 601 is formed on the SiO film 611 remaining on the light-receiving surface side, at both the sides and corners of the photoelectric conversion region 11. In step S137, the trenches of the inter-pixel isolation portions 13 located at the corners of the photoelectric conversion region 11 are filled with a conductive material that will become the conductive material film 601.

[0339] In step S138, the conductive material film 601 formed on the light-receiving surface side of both the side and corner portions of the photoelectric conversion region 11 is removed by, for example, CMP.

[0340] In step S139, the SiO film 611 formed on the light-receiving surface side is removed from both the side and corner portions of the photoelectric conversion region 11. As shown in step S139, the inter-pixel isolation portions 13 formed on the side portions of the photoelectric conversion region 11 are configured to include the SiO film 611, and the inter-pixel isolation portions 13 formed on the corner portions of the photoelectric conversion region 11 are configured to include the conductive material film 601.

[0341] Through these steps, it is possible to manufacture the inter-pixel isolation portions 13 having the conductive material film 601 at the corners of the photoelectric conversion region 11 shown in Figures 77 and 78. Although not described further, imaging devices k other than the imaging device k exemplified here can also be manufactured by applying the above-described steps and inserting necessary steps as appropriate. It is also possible to implement a combination of the eleventh embodiment and the tenth embodiment. It is also possible to apply the tenth embodiment to the inter-pixel isolation portions 13 located at the sides of the photoelectric conversion region 11, and the eleventh embodiment to the inter-pixel isolation portions 13 located at the corners of the photoelectric conversion region 11.

[0342] According to the eleventh embodiment, the cross-sectional area of ​​the current path can be increased, and the amount of voltage drop can be reduced in both the vertical and horizontal directions of the trench in the pixel separation portion 13, thereby improving the dark characteristics. By forming the conductive material film 601 using a conductive material that has lower electrical resistance than the transparent electrode 24, a configuration can be achieved that further suppresses voltage drop, making it possible to save power.

[0343] <Twelfth embodiment> In the imaging device 100m in the twelfth embodiment described below, the same parts as those in the imaging devices 100a and 100b in the first or second embodiment shown in Figure 3 or Figure 16 are given the same reference numerals, and their descriptions will be omitted as appropriate.

[0344] Figure 88 is an enlarged view of a sidewall portion of the inter-pixel isolation portion 13 of the image pickup device 100 according to the first to eleventh embodiments. The inter-pixel isolation portion 13 of the image pickup device 100 shown in Figure 88 is configured such that a fixed charge film 20 is laminated on the photoelectric conversion region 11, an insulating film 22 is laminated on the fixed charge film 20, and a transparent electrode 24 is laminated on the insulating film 22. In the image pickup device 100 having such a configuration, a negative bias is constantly applied to the transparent electrode 24 to induce holes on the sidewall of the inter-pixel isolation portion 13 in order to reduce dark current.

[0345] The imaging device 100m in the twelfth embodiment is not configured to constantly apply a negative bias, but is configured, for example, to apply a voltage during manufacturing so that holes can be induced on the side walls of the inter-pixel isolation portion 13. The configuration of the inter-pixel isolation portion 13 in the twelfth embodiment and a method of applying a negative bias to the inter-pixel isolation portion 13 will be described with reference to Fig. 89 .

[0346] The inter-pixel isolation portion 13 of the image pickup device 100m according to the twelfth embodiment has a configuration in which a ferroelectric film 701 is laminated on the photoelectric conversion region 11, and a transparent electrode 24 is laminated on the ferroelectric film 701. As shown in the left diagram of Fig. 89 , at time T1, a voltage is applied between the photoelectric conversion region 11 (silicon substrate 111) and the transparent electrode 24. Time T1 is, for example, the timing at which the image pickup device 100m is manufactured.

[0347] The ferroelectric film 701 is a layer containing a ferroelectric material, and becomes polarized when a voltage is applied. At time T1, a voltage is applied to the ferroelectric film 701, so that the photoelectric conversion region 11 side becomes negative and the transparent electrode 24 side becomes positive, as shown in Fig. 89. By polarizing the photoelectric conversion region 11 side to negative, holes are induced on the ferroelectric film 701 side of the photoelectric conversion region 11.

[0348] By applying a voltage to the ferroelectric film 701 once and aligning the direction of the spontaneous polarization, holes can be induced on the sidewall of the photoelectric conversion region 11 after that (time T2) without applying a bias, and the state in which holes are induced can be maintained. This eliminates the need to constantly apply a bias, and reduces power consumption.

[0349] Fig. 90 is a diagram showing an example of a cross-sectional configuration of an imaging device 100m according to embodiment 12-1 and an example of an enlarged cross-sectional configuration of a portion of the inter-pixel isolation section 13. The inter-pixel isolation section 13 shown in Fig. 90 is configured in the same way as the configuration of the inter-pixel isolation section 13 shown in Fig. 89, in which a ferroelectric film 701 is stacked on the photoelectric conversion region 11 and a transparent electrode 24 is stacked on the ferroelectric film 701.

[0350] The inter-pixel isolation portion 13 of the imaging device 100m in the embodiment 12-1 shown in Figure 90 is configured such that a ferroelectric film 701 is formed in the region where the fixed charge film 20 and the insulating film 22 of the inter-pixel isolation portion 13 of the imaging device 100a in the first embodiment shown in Figure 3 were formed, for example.

[0351] Here, the explanation will be given by taking the inter-pixel isolation portion 13 as an example with reference to an enlarged view of the inter-pixel isolation portion 13, but the ferroelectric film 701 is also provided on the light-receiving surface side. In the example shown in Fig. 90, the ferroelectric film 701 is also formed between the transparent electrode 24 provided on the light-receiving surface side and the photoelectric conversion region 11. Similarly, in the following explanation, the ferroelectric film 701 and layers (films) stacked on the ferroelectric film 701 are also provided on the light-receiving surface side.

[0352] As explained with reference to Fig. 89 , a voltage is applied to the ferroelectric film 701 during manufacturing, for example, to align the direction of spontaneous polarization. Therefore, although the imaging device 100m shown in Fig. 90 includes a transparent electrode 24, there is no need to apply a voltage to the transparent electrode 24. The imaging device 100m according to the twelfth embodiment may be configured without the transparent electrode 24 after a voltage has been applied to the ferroelectric film 701.

[0353] For example, during manufacturing, after applying a voltage to the ferroelectric film 701, the transparent electrode 24 can be removed, and a material other than the transparent electrode 24, such as a metal, can be filled into the inter-pixel separation portion 13, resulting in a configuration in which a metal film is provided, or a configuration in which SiO or the like is filled and a SiO film is provided.

[0354] In the case of a configuration in which the transparent electrode 24 is laminated even after the ferroelectric film 701 is polarized, as in the imaging device 100m shown in Figure 90, a mechanism may be provided in which a voltage is applied to the transparent electrode 24 when the imaging device 100m is turned on or every time a predetermined time has elapsed, thereby resetting the polarization of the ferroelectric film 701.

[0355] It is also possible to configure the transparent electrode 24 so that a voltage is constantly applied to the transparent electrode 24. In this case, the voltage value may be small, and power consumption can be reduced.

[0356] The ferroelectric film 701 may be made of HfZrO4, HfSiO4, HfAlO, BaTiO3, PbZrO3, PbTiO3, ZnO, or the like.

[0357] In the embodiments described above and below, an example is given in which the trench of the inter-pixel isolation portion 13 is provided so as to penetrate the silicon substrate 111, but the present technology can also be applied to cases in which the trench is provided so as not to penetrate the silicon substrate 111.

[0358] Fig. 91 is a diagram showing an example of a cross-sectional configuration of an image pickup device 100m according to the embodiment 12-2 and an example of a cross-sectional configuration enlarging a portion of the inter-pixel isolation portion 13. The image pickup device 100m according to the embodiment 12-2 shown in Fig. 91 differs from the image pickup device 100m according to the embodiment 12-1 shown in Fig. 90 in that a seed layer 711 is formed between the photoelectric conversion region 11 and the ferroelectric film 701, but is otherwise similar.

[0359] The seed layer 711 can be made of TiO, WO, MoO, etc. By providing the seed layer 711, the amount of polarization can be improved and the negative bias strength can be increased.

[0360] Fig. 92 is a diagram showing an example of a cross-sectional configuration of an image pickup device 100m according to the embodiment 12-3 and an example of a cross-sectional configuration enlarging a portion of the inter-pixel isolation portion 13. The image pickup device 100m according to the embodiment 12-3 shown in Fig. 92 differs from the image pickup device 100m according to the embodiment 12-1 shown in Fig. 90 in that a pressure layer 721 is formed between the ferroelectric film 701 and the transparent electrode 24, but is otherwise similar.

[0361] NbO, WO, TaO, etc. can be used as the material of the pressure layer 721. By providing the pressure layer 721, pressure can be applied to the ferroelectric film 701, the amount of polarization can be improved, and the negative bias strength can be increased.

[0362] 93 is a diagram showing an example of a cross-sectional configuration of an image pickup device 100m according to embodiment 12-4 and an example of a cross-sectional configuration enlarging a portion of the inter-pixel isolation portion 13. The image pickup device 100m according to embodiment 12-4 shown in FIG. 93 has a configuration in which a fixed charge film 20 is laminated on a photoelectric conversion region 11, an insulating film 22 is laminated on the fixed charge film 20, a ferroelectric film 701 is laminated on the insulating film 22, and a transparent electrode 24 is laminated on the ferroelectric film 701.

[0363] The imaging device 100m of the embodiment 12-4 shown in Figure 93 is configured by adding a ferroelectric film 701 to the inter-pixel separation portion 13 of the imaging device 100a of the first embodiment shown in Figure 3, and the ferroelectric film 701 is configured to be provided between the insulating film 22 and the transparent electrode 24.

[0364] The imaging device 100m according to the 12-4th embodiment can achieve a reduction in dark current by combining with the pinning layer, and can further reduce the generation of dark current.

[0365] 94 is a diagram showing a cross-sectional configuration example of an image pickup device 100m according to the embodiment 12-5 and an enlarged cross-sectional configuration example of a portion of the inter-pixel isolation portion 13. The image pickup device 100m according to the embodiment 12-5 shown in FIG. 94 has a configuration in which a fixed charge film 20 is laminated on the photoelectric conversion region 11, a ferroelectric film 701 is laminated on the fixed charge film 20, and a transparent electrode 24 is laminated on the ferroelectric film 701.

[0366] The imaging device 100m according to the embodiment 12-5 shown in FIG. 94 has a configuration in which the insulating film 22 is removed from the configuration of the inter-pixel isolation portion 13 of the imaging device 100m according to the embodiment 12-4 shown in FIG. 93.

[0367] The imaging device 100m according to the 12-5th embodiment can achieve a reduction in dark current by combining with the pinning layer, and can further reduce the generation of dark current.

[0368] Fig. 95 is a diagram showing an example of a cross-sectional configuration of an image pickup device 100m according to the embodiment 12-6 and an example of a cross-sectional configuration enlarging a portion of the inter-pixel separation unit 13. In the image pickup device 100m according to the embodiment 12-6 shown in Fig. 95, the configuration of the inter-pixel separation unit 13 is similar to the configuration of the inter-pixel separation unit 13 of the image pickup device 100m according to the embodiment 12-1 in Fig. 90, but differs in that the transparent electrode 24 provided on the light receiving surface side is not provided.

[0369] 95 shows an imaging device 100m according to the embodiment 12-6, which is configured such that the transparent electrode 24 is not provided on the light-receiving surface side. Instead of the transparent electrode 24, an oxide film 741 containing a material such as TaO, TiO, or HfO is formed on the light-receiving surface side. Note that it is also possible to form a configuration in which only the cap film 26 is formed without the oxide film 741 being formed.

[0370] On the light-receiving surface side, a ferroelectric film 701 is formed on the photoelectric conversion region 11, an oxide film 741 is formed on the ferroelectric film 701, and a cap film 26 is formed on the oxide film 741. Since the transparent electrode 24 is not disposed on the light-receiving surface side, for example, during manufacturing, no voltage is applied to the ferroelectric film 701 provided on the light-receiving surface side.

[0371] In such a case, the ferroelectric film 701 provided on the light-receiving surface side may not have the same direction of spontaneous polarization, but the ferroelectric film 701 on the trench side surface has the same direction of spontaneous polarization, so that holes are induced inside the trench and the generation of dark current is suppressed.

[0372] 96 is a diagram showing a cross-sectional configuration example of an image pickup device 100m according to the embodiment 12-7 and an enlarged cross-sectional configuration example of a portion of the inter-pixel isolation portion 13. The image pickup device 100m according to the embodiment 12-7 shown in FIG. 96 has a configuration in which a fixed charge film 20 is laminated on a photoelectric conversion region 11, an insulating film 22 is laminated on the fixed charge film 20, a transparent electrode 24-2 is laminated on the insulating film 22, a ferroelectric film 701 is laminated on the transparent electrode 24-2, and the transparent electrode 24-2 is laminated on the ferroelectric film 701.

[0373] The imaging device 100m of the embodiment 12-7 shown in Figure 96 is configured by adding a ferroelectric film 701 near the center of the transparent electrode 24 filling the inter-pixel separation portion 13 of the imaging device 100a of the first embodiment shown in Figure 3.

[0374] 97 is an enlarged view of the inter-pixel separator 13 and the light-receiving surface side configuration of the image pickup device 100m according to the embodiment 12-7. The transparent electrode 24-1 is formed on the light-receiving surface side and is provided continuously on the light-receiving surface side (in the horizontal direction). Another transparent electrode 24-1 is provided near the center of the inter-pixel separator 13, and the transparent electrode 24-1 provided in the vertical direction is connected to the transparent electrode 24-1 provided in the horizontal direction.

[0375] The transparent electrode 24-1 is connected to a supply source 721-1 that applies a predetermined voltage, for example, in the peripheral portion 2 (FIG. 2). Therefore, the transparent electrode 24-1 disposed on one side of the ferroelectric film 701 is configured to receive a voltage supplied from the supply source 721-1.

[0376] The transparent electrode 24-2 is formed on the light-receiving surface side, and the transparent electrode 24-2 formed on the light-receiving surface side is formed continuously with the transparent electrode 24-2 formed on one side surface of the inter-pixel separation section 13. The transparent electrode 24-2 formed on one side surface of the inter-pixel separation section 13 is also formed continuously with the transparent electrode 24-2 formed on the other side surface, via the transparent electrode 24-2 formed on the bottom surface.

[0377] Such a continuously formed structure of the transparent electrode 24-2 continues, for example, to the peripheral portion 2 (FIG. 2), and is connected to a wiring (terminal) that is connected to a supply source 721-2 that applies a predetermined voltage and is provided in the peripheral portion 2. Therefore, a voltage supplied from the supply source 721-2 is applied to the transparent electrode 24-2 disposed on the other side of the ferroelectric film 701.

[0378] A voltage from a supply source 721-1 is applied to one side of the ferroelectric film 701, and a voltage from a supply source 721-2 is applied to the other side of the ferroelectric film 701. A differential voltage between the voltage supplied by the supply source 721-1 and the voltage supplied by the supply source 721-2 is applied to the ferroelectric film 701. Since a predetermined voltage is applied to the ferroelectric film 701, spontaneous polarization can be generated in the ferroelectric film 701 and the direction of the spontaneous polarization can be aligned, as in the above-described embodiment.

[0379] The supply source 721-1 and the supply source 721-2 are supply sources that supply different voltages, and either one may be a supply source that supplies the ground potential.

[0380] The imaging device 100m according to the 12-7th embodiment can reduce the voltage required to maintain a negative bias.

[0381] According to the twelfth embodiment, by providing the ferroelectric film 701, holes can be induced in the photoelectric conversion region 11, thereby reducing dark current. Once a voltage is applied to the ferroelectric film 701 at least once to align the polarization direction, there is no need to apply a voltage thereafter. This eliminates the need to continuously apply a negative bias, and reduces the power consumption required for applying a negative bias.

[0382] The first to twelfth embodiments can also be implemented in combination of two or more.

[0383] <Application Example to Endoscopic Surgery System> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0384] FIG. 98 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0385] Figure 98 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0386] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0387] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. 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 by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0388] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0389] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various types of image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0390] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0391] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing the surgical site, etc.

[0392] The input device 11204 is an input interface for the endoscopic surgery system 11000. A 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 to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0393] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0394] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0395] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0396] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissue (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0397] Figure 99 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in Figure 98.

[0398] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0399] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0400] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0401] Furthermore, 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.

[0402] The driving 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. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0403] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0404] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0405] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0406] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0407] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0408] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0409] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0410] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0411] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 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 technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0412] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0413] In the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0414] <Application to a Mobile Body> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0415] FIG. 100 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology of the present disclosure can be applied.

[0416] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 100, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0417] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0418] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0419] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0420] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0421] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. 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 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0422] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0423] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0424] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0425] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to vehicle occupants or the outside of the vehicle. In the example of Fig. 100, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0426] FIG. 101 is a diagram showing an example of the installation position of the imaging unit 12031.

[0427] In FIG. 101, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0428] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0429] 101 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0430] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0431] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation.

[0432] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0433] At least one of the image capturing 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 a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0434] <Other Embodiments> As described above, the present disclosure has been described with reference to the embodiments and modifications. However, the descriptions and drawings that form part of this disclosure should not be understood as limiting the present disclosure. Various alternative embodiments, examples, and application techniques will become apparent to those skilled in the art from this disclosure. It goes without saying that the present technology includes various embodiments not described herein. Various omissions, substitutions, and / or modifications of components may be made without departing from the spirit of the above-described embodiments and modifications. Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0435] The present disclosure may also be configured as follows: (1) A photodetector comprising: a semiconductor layer having a light-receiving surface; pixels provided in the semiconductor layer and having photoelectric conversion regions that photoelectrically convert light incident on the light-receiving surface; a first trench disposed between one of the pixels and another of the pixels, the first trench being open at least toward the light-receiving surface; and a transparent electrode made of a transparent oxide semiconductor that transmits the light and covering the light-receiving surface and a sidewall of the first trench. (2) The photodetector according to (1), in which a negative voltage is applied to the transparent electrode. (3) The photodetector according to (1) or (2), in which the transparent oxide semiconductor includes one or more of InO, IGZO, ITO, IZO, ZnO, SnO, and CdO. (4) The photodetector according to any of (1) to (3), in which the first trench is not completely filled with the transparent electrode and a void is present. (5) The photodetector according to any one of (1) to (4), further comprising a second trench disposed between adjacent first and second photoelectric conversion regions in the pixel and opening at least on the light-receiving surface side of the semiconductor layer, wherein the transparent electrode covers a sidewall of the second trench. (6) The photodetector according to (5), wherein the second trench is not completely filled with the transparent electrode, leaving a gap therein. (7) The photodetector according to any one of (1) to (6), further comprising a cap film provided on the light-receiving surface side of the semiconductor layer and covering the transparent electrode. (8) The photodetector according to (7), wherein the cap film is made of one or more films of SiO, SiN, Al2O3, IZO, and IGZO. (9) The photodetector according to any one of (1) to (8), wherein the transparent electrode has a first region and a second region having a higher impurity concentration than the first region. (10) The photodetector according to (9), further comprising a conductor in contact with the second region. (11) The photodetector according to (10), wherein the conductor is an optical black section disposed outside a pixel section in which the plurality of pixels are disposed.(12) The photodetector according to any one of (1) to (11), further comprising a fixed charge film provided between the transparent electrode and the semiconductor layer. (13) The photodetector according to any one of (1) to (12), further comprising a diffusion prevention film between the transparent electrode and the photoelectric conversion region, the diffusion prevention film preventing diffusion of metal impurities from the transparent electrode to the photoelectric conversion region. (14) The photodetector according to (13), wherein the diffusion prevention film is composed of a film containing one or more of SiN, SiCN, TiN, TaN, and WN. (15) The photodetector according to (13), wherein the diffusion prevention film is composed of a film doped with one of carbon, fluorine, and boron. (16) The photodetector according to any one of (1) to (15), further comprising a leakage prevention film between the transparent electrode and the photoelectric conversion region, the leakage prevention film preventing leakage current from occurring between the transparent electrode and the photoelectric conversion region. (17) The photodetector according to (16), wherein the leak prevention film is composed of a film containing any one of Al2O3, HfO2, ZrO, TaO, TiO2, NbO, and La2O3. (18) The photodetector according to (16) or (17), wherein the leak prevention film is a film in which two or more types of films are stacked. (19) The photodetector according to any one of (1) to (18), wherein the transparent electrode or the film stacked on the transparent electrode is a film in an oxygen-deficient state. (20) The photodetector according to (19), wherein the film stacked on the transparent electrode is an insulating film and is provided between the transparent electrode and the photoelectric conversion region. (21) The photodetector according to any one of (1) to (20), wherein a hydrogen supply film that supplies hydrogen is stacked on the transparent electrode covering the sidewall of the first trench. (22) The photodetector according to (21), wherein the hydrogen supply film is a film containing TiN. (23) The photodetector according to any one of (1) to (22), wherein a hydrogen sealing film for sealing in hydrogen is laminated on the transparent electrode provided on the light-receiving surface side. (24) The photodetector according to (23), wherein the hydrogen sealing film is a film containing Al2O3.(25) The photodetector according to any one of (1) to (24), wherein the transparent electrode provided on the light-receiving surface side is formed of a material with high amorphous properties. (26) The photodetector according to any one of (1) to (25), wherein a metal film is laminated on the transparent electrode in the first trench. (27) The photodetector according to (26), wherein a liner film is formed between the metal film and the transparent electrode. (28) The photodetector according to (26) or (27), further comprising a light-shielding film on a cap film laminated on the transparent electrode on the light-receiving surface side, wherein the light-shielding film and the metal film are connected. (29) The photodetector according to any one of (1) to (28), wherein a conductive material film made of a conductive material is provided in the first trench. (30) The photodetector according to (29), wherein at least one of a SiO film containing SiO and a void is further provided in the first trench. (31) The photodetector according to (28) or (29), wherein the conductive material film is provided at a corner of the photoelectric conversion region. (32) A photodetector comprising: a semiconductor layer having a light-receiving surface; pixels provided in the semiconductor layer and having photoelectric conversion regions that photoelectrically convert light incident on the light-receiving surface; a first trench disposed between one of the pixels and the other of the pixels, the first trench opening at least toward the light-receiving surface; and a ferroelectric film made of a transparent oxide semiconductor that transmits light, the ferroelectric film including a ferroelectric covering the light-receiving surface and a sidewall of the trench. (33) The photodetector according to (32), wherein the ferroelectric film has a uniform polarization direction. (34) The photodetector according to (32) or (33), wherein the ferroelectric film contains any one of HfZrO4, HfSiO4, HfAlO, BaTiO3, PbZrO3, PbTiO3, and ZnO. (35) The photodetector according to any one of (32) to (34), wherein a transparent electrode is stacked on the ferroelectric film. (36) The photodetector according to any one of (32) to (35), further comprising a layer containing any one of TiO, WO, and MoO between the photoelectric conversion region and the ferroelectric film.(37) The photodetector according to any one of (32) to (36), further comprising a layer containing any one of NbO, WO, and TaO between the transparent electrode and the ferroelectric film. (38) The photodetector according to any one of (32) to (37), further comprising a fixed charge film between the photoelectric conversion region and the ferroelectric film. (39) The photodetector according to (38), further comprising an insulating film between the photoelectric conversion region and the fixed charge film. (40) The photodetector according to (32), in which a first transparent electrode is stacked on one side of the ferroelectric film and a second transparent electrode is stacked on the other side. (41) The photodetector according to (40), in which the first transparent electrode and the second transparent electrode are respectively connected to supply sources that supply different voltages.

[0436] 1 Pixel portion, 2 Peripheral portion, 11 Photoelectric conversion region, 13 Inter-pixel isolation portion, 15 Intra-pixel isolation portion, 20 Fixed charge film, 22 Insulating film, 24 Transparent electrode, 26 Cap film, 30 Sidewall layer, 32 Insulating film, 51 Film formation, 100 Imaging device, 102 Light-shielding film, 111 Substrate, 111a Front surface, 111b Back surface, 112 Pixel, 113 Pixel region, 114 Vertical drive circuit, 115 Column signal processing circuit, 116 Horizontal drive circuit, 117 Output circuit, 118 Control circuit, 119 Vertical signal line, 120 Horizontal signal line, 121 Pixel, 130 Interlayer insulating film, 131 First insulating film, 132 Second insulating film, 133 Third insulating film 134 fourth insulating film, 140 wiring layer, 141 wiring, 142 wiring, 150 barrier metal layer, 160 OPB layer, 161 first OPB layer, 162 second OPB layer, 171 first region, 172 second region, 201 diffusion prevention film, 221 leakage prevention film, 241 transparent electrode, 243 insulating film, 251 anti-reflection film, 301 hydrogen supply film, 321 hydrogen sealing film, 323 anti-reflection film, 325 transparent electrode, 341 high-temperature formed oxide film, 343 SiO film, 345 SiN film, 349 high K film, 351 diffusion prevention film, 353 anti-reflection film, 401 metal film, 402 light-shielding film, 411 refractive layer 413 Air layer, 415 High flexibility material layer, 417 Liner film, 501 Conductive material film, 511 SiO film, 601 Conductive material film, 611 SiO film, 621 Conductive material film, 623 Conductive material film, 701 Ferroelectric film, 711 Seed layer, 721 Pressure layer, 721 Supply source, 741 Oxide film

Claims

1. A photodetector comprising: a semiconductor layer having a light-receiving surface; pixels provided in the semiconductor layer and having photoelectric conversion regions that photoelectrically convert light incident on the light-receiving surface; a first trench disposed between two adjacent pixels among the plurality of pixels and opening at least toward the light-receiving surface; and a transparent electrode made of a transparent oxide semiconductor that transmits the light, covering the light-receiving surface and a sidewall of the first trench.

2. The photodetector according to claim 1, wherein a negative voltage is applied to the transparent electrode.

3. The photodetector according to claim 1, wherein the transparent oxide semiconductor includes one or more of InO, IGZO, ITO, IZO, ZnO, SnO, and CdO.

4. The photodetector according to claim 1, wherein the first trench is not completely filled with the transparent electrode, and a void exists therein.

5. The photodetector according to claim 1, further comprising a second trench disposed within the pixel between adjacent first and second photoelectric conversion regions and opening at least toward the light-receiving surface of the semiconductor layer, and wherein the transparent electrode covers the sidewall of the second trench.

6. The photodetector according to claim 5, wherein the second trench is not completely filled with the transparent electrode, and a void exists therein.

7. The photodetector according to claim 1, further comprising a cap film provided on the light-receiving surface side of the semiconductor layer and covering the transparent electrode.

8. The photodetector according to claim 7, wherein the cap film is made of one or more of SiO, SiN, Al2O3, IZO, and IGZO.

9. The photodetector according to claim 1, wherein the transparent electrode has a first region and a second region having a higher impurity concentration than the first region.

10. The photodetector device of claim 9, further comprising a conductor in contact with said second region.

11. The photodetector according to claim 10, wherein the conductor is an optical black section arranged outside a pixel section in which the plurality of pixels are arranged.

12. The photodetector according to claim 1, further comprising a diffusion prevention film between said transparent electrode and said photoelectric conversion region, for preventing diffusion of metal impurities from said transparent electrode to said photoelectric conversion region.

13. The photodetector according to claim 1, further comprising a leakage prevention film between the transparent electrode and the photoelectric conversion region to prevent leakage current from occurring between the transparent electrode and the photoelectric conversion region.

14. The photodetector according to claim 1, wherein the transparent electrode or the film laminated on the transparent electrode is an oxygen-deficient film.

15. The photodetector according to claim 1, wherein a hydrogen supply film for supplying hydrogen is laminated on the transparent electrode covering the sidewall of the first trench.

16. The photodetector according to claim 1, wherein a hydrogen sealing film for sealing in hydrogen is laminated on the transparent electrode provided on the light-receiving surface side.

17. The photodetector according to claim 1, wherein a high-temperature oxide film formed at a high temperature is laminated on the transparent electrode covering the sidewall of the first trench.

18. The photodetector according to claim 1, wherein a metal film is laminated on the transparent electrode in the first trench.

19. The photodetector device according to claim 1, further comprising a conductive material film formed of a conductive material within the first trench.

20. The photodetector according to claim 19, wherein the conductive material film is provided at a corner of the photoelectric conversion region.

Images