Light detection device

Abstract

Provided is a light detection device in which a decrease in light absorption in a photoelectric conversion layer can be suppressed.　A light detection device according to the present invention comprises a pixel substrate in which at least a first electrode, a photoelectric conversion layer, and a second electrode are laminated in this order from a light incident side, the pixel substrate having at least one pixel, wherein the first electrode has an opening corresponding to the at least one pixel. According to the light detection device according to the present invention, a decrease in light absorption in the photoelectric conversion layer can be suppressed.

Description

Photodetector

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a light detection device.

[0002] 2. Description of the Related Art Conventionally, a photodetection device having pixels such as an image sensor is known.

[0003] Among conventional photodetectors, there is one in which light is incident on a photoelectric conversion layer via a transparent electrode (see, for example, Patent Document 1).

[0004] International Publication No. 2022 / 234806

[0005] However, conventional photodetectors have room for improvement in terms of suppressing the decrease in light absorption in the photoelectric conversion layer.

[0006] Therefore, a main object of the present technology is to provide a photodetector capable of suppressing a decrease in light absorption in a photoelectric conversion layer.

[0007] The present technology provides a photodetector device including a pixel substrate having at least one pixel, the pixel substrate including at least a first electrode, a photoelectric conversion layer, and a second electrode stacked in this order from a light incident side, the pixel substrate having the at least one pixel, the first electrode having an opening corresponding to the at least one pixel. The pixel substrate may include a carrier transport layer disposed between the first electrode and the photoelectric conversion layer. The carrier transport layer may have another opening corresponding to the opening. The ratio of the area of ​​the opening to the area of ​​the at least one pixel may be 0.20 to 0.95. A light absorption layer may be provided on a surface of the first electrode on the light incident side, in a portion surrounding the opening. When viewed from the light incident side, the first and second electrodes may not overlap. When viewed from the light incident side, the first and second electrodes may have an overlapping portion, and the area of ​​the overlapping portion may be smaller than the area of ​​the opening. The first electrode may have light-blocking properties. The shape of the opening may be n-fold symmetric (n≧2). The shape of the opening may be anisotropic. The opening may correspond to half of the pixel. The at least one pixel may be a plurality of pixels arranged in a two-dimensional array, and the first electrode may have a portion spanning at least two of the plurality of pixels. The spanning portion may span all of the plurality of pixels. The at least two pixels may be adjacent to each other at their edges, and the spanning portion may be located at a position that includes at least a portion of the adjacent edges of the at least two pixels. The at least two pixels may be adjacent to each other at their corners, and the spanning portion may be located at a position that includes the adjacent corners of the at least two pixels. The at least two pixels may be adjacent to each other at their edges and corners, and the first electrode may have the spanning portion located at a position that includes at least a portion of the adjacent edges of the at least two pixels and the spanning portion located at a position that includes the adjacent corners of the at least two pixels. The spanning portion may extend in a direction passing through the centers of the at least two pixels.The pixel device may further include a light-collecting structure disposed on the light incident side of the pixel substrate and corresponding to at least one of the pixels. The pixel device may further include a processing substrate disposed on the opposite side of the pixel substrate from the light incident side, and may have a via penetrating at least the photoelectric conversion layer and electrically connecting the first electrode and the processing substrate. A guard electrode for applying a voltage may be provided surrounding the second electrode.

[0008] 1 is a schematic configuration diagram of a photodetector according to an embodiment of the present technology. FIG. 1 is a partial cross-sectional view of a photodetector according to an embodiment of the present technology. FIG. 2 is a cross-sectional view of a pixel of a photodetector according to Example 1 of an embodiment of the present technology. FIG. 3 is a plan view of a first electrode of a pixel of a photodetector according to Example 1 of an embodiment of the present technology, as viewed from above. FIG. 4 is a cross-sectional view of a pixel of a photodetector according to Comparative Example 1. FIG. 5 is a diagram for explaining a photodetection operation of a photodetector according to Example 1 of an embodiment of the present technology. FIG. 6 is a flowchart for explaining an example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. FIGS. 8A to 8C are cross-sectional views of steps in the example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. FIGS. 9A to 9C are cross-sectional views of steps in the example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. FIGS. 10A to 10C are cross-sectional views of steps in the example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. FIGS. 11A and 11B are cross-sectional views of steps in the example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. FIGS. 12A and 12B are cross-sectional views of steps in the example of a manufacturing method of a photodetector according to Example 1 of an embodiment of the present technology. 13A and 13B are cross-sectional views of steps in an example of a method for manufacturing a photodetector according to Example 1 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Comparative Example 2. A cross-sectional view of a pixel of a photodetector according to Example 2 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 3 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 4 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 5 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 6 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 7 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 8 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 9 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 10 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 11 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 12 of an embodiment of the present technology. A cross-sectional view of a pixel of a photodetector according to Example 13 of an embodiment of the present technology.31A and 31B are plan views of pixel arrays of photodetector devices according to Modifications 3 and 4 of an embodiment of the present technology, respectively, as viewed from above the first electrodes thereof. FIGS. 32A to 32C are plan views of pixel arrays of photodetector devices according to Modifications 5 to 7 of an embodiment of the present technology, respectively, as viewed from above the first electrodes thereof. FIGS. 33A to 33D are plan views of pixel arrays of photodetector devices according to Modifications 8 to 11 of an embodiment of the present technology, respectively, as viewed from above the first electrodes thereof. FIGS. 34A to 34C are plan views of pixel arrays of photodetector devices according to Modifications 12 to 14 of an embodiment of the present technology, respectively, as viewed from above the first electrodes thereof. 35A and 35B are plan views seen from above the first electrodes of pixel arrays of photodetector devices according to Modifications 15 and 16 of an embodiment of the present technology. FIGS. 36A and 36B are plan views seen from above the first electrodes of pixel arrays of photodetector devices according to Modifications 17 and 18 of an embodiment of the present technology. FIGS. 37A and 37B are plan views seen from above the first electrodes of pixel arrays of photodetector devices according to Modifications 19 and 20 ...B are plan views seen from below the first electrodes of pixel arrays of photodetector devices according to Modifications 21 and 22 of an embodiment of the present technology. FIGS. 39A to 39C are plan views seen from below the second electrodes of pixel arrays of photodetector devices according to Modifications 22 to 24 of an embodiment of the present technology. FIGS. 39A to 39C are plan views seen from below the second electrodes of pixel arrays of photodetector devices according to Modifications 25 and 26 of an embodiment of the present technology. FIGS. 41A to 41D are plan views seen from below the second electrodes of pixel arrays of photodetector devices according to Modifications 26 to 29 of an embodiment of the present technology. Fig. 42A is a diagram for explaining an example in which the first electrode and the second electrode do not overlap when viewed from the light incident side. Fig. 42B is a diagram for explaining an example in which the first electrode and the second electrode overlap when viewed from the light incident side. Fig. 43A is a diagram showing a dark current path in the example of Fig. 42A. Fig. 43B is a diagram showing a dark current path in the example of Fig. 42B.44A is a partial cross-sectional view of a pixel array having a plurality of pixels of a photodetector according to Example 3 of an embodiment of the present technology. FIG. 44B is a perspective view of a pixel array having a plurality of pixels of a photodetector according to Example 3 of an embodiment of the present technology. FIG. 45A is a partial cross-sectional view of Modified Example 1 of a pixel of a photodetector according to an embodiment of the present technology. FIG. 45B is a partial cross-sectional view of Modified Example 2 of a pixel of a photodetector according to an embodiment of the present technology. FIG. 46A is a partial cross-sectional view of Modified Example 3 of a pixel of a photodetector according to an embodiment of the present technology. FIG. 46B is a partial cross-sectional view of Modified Example 4 of a pixel of a photodetector according to an embodiment of the present technology. FIG. 48A is a schematic diagram showing an example of the overall configuration of a photodetection system using a photodetector. FIG. 48B is a diagram showing an example of the circuit configuration of the photodetector system of FIG. 48A. A diagram showing an example of use of a photodetector to which the present technology is applied. A functional block diagram of an example of an electronic device including a photodetector to which the present technology is applied. FIG. 48B is a diagram showing an example of a schematic configuration of an endoscopic surgery system. FIG. 2 is a block diagram showing an example of the functional configuration of a camera head and a CCU.

[0009] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below illustrate typical embodiments of the present technology, and the scope of the present technology should not be interpreted as being narrow. Even when it is described in this specification that the photodetector according to the present technology has multiple effects, it is sufficient that the photodetector according to the present technology has at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0010] The description will be made in the following order: 0. Introduction 1. Schematic configuration example of a light detection device according to an embodiment of the present technology 2. Light detection devices according to examples 1 to 14 of an embodiment of the present technology 3. Light detection devices according to modified examples 1 to 29 of an embodiment of the present technology 4. Effects of a light detection device according to an embodiment of the present technology 5. Configuration example of a light detection device mounted on an electronic device 6. Light detection system using a light detection device 7. Other modified examples of the present technology 8. Use example of a light detection device to which the present technology is applied 9. Other use example of a light detection device to which the present technology is applied 10. Application example to a moving body, etc. 11. Application example to an endoscopic surgery system

[0011] <0. Introduction> Conventionally, photodetectors have been known that apply a voltage between a pair of electrodes sandwiching a photoelectric conversion layer and collect signal charges generated by photoelectric conversion. A solid transparent electrode is used as the electrode (upper electrode) of the pair of electrodes that is disposed on the side where light is incident (light incident side). That is, in conventional photodetectors, incident light is incident on the photoelectric conversion layer through the transparent electrode.

[0012] The inventors have conducted the following investigation into conventional photodetectors and have found that there is a strong need to suppress a decrease in light absorption in the photoelectric conversion layer due to light absorption in the transparent electrode.

[0013] A solid transparent electrode, for example, absorbs light in the SWIR (short wavelength infrared) band, but the amount is not very large, at around 1-4%. However, if this light is concentrated or reflected, it is estimated that a maximum loss of 12-14% occurs in the SWIR band.

[0014] That is, in conventional photodetectors, there is a concern that the attenuation of incident light by the solid transparent electrode, which is the electrode on the light incident side, reduces absorption in the photoelectric conversion layer and reduces EQE (external quantum efficiency).

[0015] Therefore, after extensive research, the inventors have succeeded in suppressing the attenuation of incident light reaching the photoelectric conversion layer and suppressing the decrease in light absorption in the photoelectric conversion layer by allowing the incident light to enter the photoelectric conversion layer through an opening provided in the upper electrode, which is a novel finding of the inventors.

[0016] The inventors have developed a photodetector according to the present technology as a photodetector that embodies this new finding. The photodetector according to the present technology has an opening in the upper electrode. This makes it possible to use an electrode other than a transparent electrode (e.g., an electrode with light-blocking properties) as the upper electrode, thereby improving the degree of freedom in selecting the material for the upper electrode. Using an electrode other than a transparent electrode as the upper electrode eliminates the concern of reduced yield due to process instability that occurs when using a transparent electrode.

[0017] To add, for example, in the SWIR band, the frequency of the electromagnetic field of light is low, and the surface charge of the transparent electrode responds to the electric field, resulting in increased absorption and reflection in the transparent electrode, resulting in a decrease in transmittance. For example, in order to avoid a decrease in transmittance compared to ITO (indium tin oxide), which is commonly used as a transparent electrode, it is possible to use a material with a low charge density (IZO, indium zinc oxide, etc.) for the transparent electrode, but in this case, the resistivity of the transparent electrode decreases, resulting in a decrease in voltage at the center of the chip. In other words, when a solid transparent electrode is used, there is a trade-off between improving the transmittance and improving the resistivity of the transparent electrode.

[0018] In particular, in a low-mobility photoelectric conversion film, such as a quantum dot (QD) layer, it is desirable to apply an electric field to efficiently collect signal charges generated by photoelectric conversion. Therefore, using a solid electrode is desirable from the viewpoint of applying an electric field. However, the high reflectivity and low transmittance of typical metal materials significantly reduces the amount of light incident on the photoelectric conversion layer. Therefore, in order to ensure the amount of light incident on the photoelectric conversion layer, a transparent electrode, such as ITO, is selected as the solid electrode. However, as mentioned above, the transparent electrode has a high absorption and reflection in the SWIR band, which reduces the absorption rate in the photoelectric conversion layer.

[0019] Furthermore, ITO and other materials commonly used as transparent electrodes are known to have low process stability, and their optical constants and work functions vary due to the effects of thermal processes, etc. Therefore, when a solid transparent electrode is used as the upper electrode, variations in transmittance and electric field between pixels occur, raising concerns about reduced yields.

[0020] Considering the above, although there are some concerns regarding the application of an electric field when a low-mobility photoelectric conversion film (e.g., a QD layer) is used in the photoelectric conversion layer, the photodetector according to the present technology is significant in that it can suppress a decrease in absorption in the photoelectric conversion layer and does not require a transparent electrode.

[0021] 1. Schematic Configuration Example of a Photodetector According to an Embodiment of the Invention Fig. 1 shows a schematic configuration of a photodetector 1 according to an embodiment of the invention. As shown in Fig. 1, the photodetector 1 is configured to have a pixel section 3 in which pixels 2, each including a photoelectric conversion section, are regularly arranged two-dimensionally on a semiconductor substrate 70 (e.g., a silicon substrate), and a peripheral circuit section. The pixel 2 is configured to have, for example, a photodiode included in the photoelectric conversion section, and a plurality of pixel transistors (so-called MOS transistors). The plurality of pixel transistors may be, for example, transfer transistors TR ＴＲＳ (See FIG. 6), reset transistor TR ＲＳＴ (see FIG. 6) and the amplifying transistor TR ＡＭＰ In addition, the selection transistor TR ＳＥＬ It is also possible to add a transistor (see FIG. 6) to configure a unit pixel with four transistors. The equivalent circuit of the unit pixel is the same as a normal one, so a detailed description will be omitted. The pixel 2 can also have a shared pixel structure. This pixel shared structure is configured with multiple photodiodes, multiple transfer transistors, one shared floating diffusion, and one other pixel transistor each.

[0022] The peripheral circuit section includes a vertical drive circuit 4, a column signal processing circuit 5, a horizontal drive circuit 6, an output circuit 7, a control circuit 8, and the like.

[0023] The control circuit 8 receives an input clock and data instructing the operation mode and the like, and outputs data such as internal information of the photodetector 1. That is, the control circuit 8 generates clock signals and control signals that serve as references for the operation of the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc., based on the vertical synchronization signal, horizontal synchronization signal, and master clock. These signals are then input to the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc.

[0024] The vertical drive circuit 4 is configured by, for example, a shift register, selects pixel drive wirings, supplies pulses for driving pixels to the selected pixel drive wirings, and drives the pixels row by row. That is, the vertical drive circuit 4 selects and scans each pixel 2 in the pixel section 3 row by row in the vertical direction, and supplies pixel signals based on signal charges generated in accordance with the amount of light received in, for example, photodiodes serving as photoelectric conversion elements of each pixel 2 to the column signal processing circuit 5 via vertical signal lines 9.

[0025] The column signal processing circuits 5 are arranged, for example, for each column of pixels 2, and perform signal processing such as noise removal for each pixel column on signals output from one row of pixels 2. That is, the column signal processing circuits 5 perform signal processing such as CDS for removing fixed pattern noise specific to the pixels 2, signal amplification, and AD conversion. A horizontal selection switch (not shown) is provided at the output stage of the column signal processing circuit 5 and connected between it and the horizontal signal line 10.

[0026] The horizontal drive circuit 6 is configured, for example, by a shift register, and sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits 5 in turn, causing each of the column signal processing circuits 5 to output a pixel signal to the horizontal signal line 10.

[0027] The output circuit 7 processes and outputs signals sequentially supplied from each of the column signal processing circuits 5 via the horizontal signal line 10. For example, the output circuit 7 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal 21 exchanges signals with the outside.

[0028] Hereinafter, the photodetector 1 according to an embodiment of the present technology will be described in detail with reference to several examples.

[0029] 2. Photodetector according to Examples 1 to 14 of an embodiment of the present technology Photodetector according to Example 1 Overall configuration of photodetector FIG. 2 is a partial cross-sectional view of a photodetector according to Example 1 of an embodiment of the present technology.

[0030] 2, the photodetector according to the first embodiment is a back-illuminated photodetector, and includes at least one (here, a plurality of) photoelectric conversion units (photodetection units). The photoelectric conversion unit is provided for each pixel 2. Here, the photoelectric conversion unit has a photoelectric conversion layer 13 that absorbs light in the SWIR band.

[0031] The photodetector according to Example 1 includes a pixel substrate 100 having at least one pixel 2, the pixel substrate 100 including at least a first electrode 11, a photoelectric conversion layer 13, and a second electrode 12 stacked in this order from the light incident side. In the pixel substrate 100, a photoelectric conversion unit is formed by a stacked structure in which at least the first electrode 11, the photoelectric conversion layer 13, and the second electrode 12 are stacked. The pixel substrate 100, for example, includes a photoelectric conversion unit, a protective layer 82, and an insulating film 110 including an interlayer insulating layer 78 and an interlayer insulating layer 81. A first carrier transport layer (electron transport layer (ETL) or hole transport layer (HTL)) is formed between the first electrode 11 and the photoelectric conversion layer 13, and a second carrier transport layer (electron transport layer or hole transport layer) is formed between the photoelectric conversion layer 13 and the second electrode 12. However, the first and second carrier transport layers are not shown in FIG. 2 . The "carrier transport layer" is a layer for transporting carriers to the electrodes, and is also called a "charge injection blocking layer" because it substantially suppresses charge injection into the photoelectric conversion layer 13. The first electrode 11 is also called an "upper electrode". The second electrode 12 is also called a "lower electrode". The first carrier transport layer is also called an "upper transport layer". The second carrier transport layer is also called a "lower transport layer".

[0032] The photodetector according to the first embodiment further includes a processing substrate 200 disposed on the opposite side of the pixel substrate 100 from the light incident side. The processing substrate 200 includes a semiconductor substrate 70, an interlayer insulating layer 77, and a plurality of transistors. The plurality of transistors constitute a readout circuit. That is, the processing substrate 200 is, for example, a ROIC (Readout Integrated Circuit) substrate.

[0033] The photodetector according to the first embodiment further includes a control unit provided on a semiconductor substrate 70 (e.g., a silicon substrate) and connected to a second electrode 12, and the photoelectric conversion unit is disposed above the semiconductor substrate 70. Here, the light incident side of the semiconductor substrate 70 is referred to as the upper side, and the side opposite to the light incident side of the semiconductor substrate 70 is referred to as the lower side. A wiring layer 62 made up of a plurality of wirings is provided above the semiconductor substrate 70. In addition, the semiconductor substrate 70 includes at least a charge accumulation unit (floating diffusion layer FD, see FIG. 6) and an amplification transistor TR that constitute the control unit. ＡＭＰ The second electrode 12 is provided between the floating diffusion layer FD and the amplification transistor TR ＡＭＰ The charge storage section (floating diffusion layer FD) stores the charges generated in the photoelectric conversion layer 13. The semiconductor substrate 70 further includes a reset transistor TR ＲＳＴ and the selection transistor TR ＳＥＬ The floating diffusion layer FD is provided with a reset transistor TR ＲＳＴ and the amplifier transistor TR ＡＭＰ One of the source / drain regions of the selection transistor TR ＳＥＬ and the select transistor TR ＳＥＬ The other source / drain region is connected to a signal line VSL (see FIG. 6). The charge storage portion (floating diffusion layer FD) is not essential.

[0034] In the photoelectric conversion section, the second electrode 12 is formed on an interlayer insulating layer 81. A protective layer 82 is formed on the entire surface including the first electrode 11, and an on-chip lens is provided on the protective layer 82 as a light-collecting structure 90. The first electrode 11 and the second electrode 12 are made of, for example, at least one type of metal. The interlayer insulating layer 81 and the protective layer 82 are made of a well-known insulating material (for example, SiO ２ The on-chip lens as the light-collecting structure 90 is made of, for example, SiO ２ , and is covered with a protective film 91 (see FIG. 3) made of SiN or the like.

[0035] An element isolation region 71 is formed on the first surface (front surface) 70A of the semiconductor substrate 70, and an oxide film 72 is formed on the first surface 70A of the semiconductor substrate 70. Furthermore, on the first surface side of the semiconductor substrate 70, a reset transistor TR constituting a control unit is formed. ＲＳＴ , amplifying transistor TR ＡＭＰ and the selection transistor TR ＳＥＬ is provided, and further, a floating diffusion layer FD is provided.

[0036] Reset transistor TR ＲＳＴ The reset transistor TR is composed of a gate portion 51, a channel forming region 51A, and source / drain regions 51B and 51C. ＲＳＴ The gate 51 of the reset transistor TR is connected to the reset line RST. ＲＳＴ One of the source / drain regions 51C also serves as a floating diffusion layer FD, and the other source / drain region 51B is connected to a power supply V ＤＤ (See FIG. 6).

[0037] The second electrode 12 is connected to the reset transistor TR via a connection hole 64 provided in the interlayer insulating layer 81, a wiring portion 60 including a pad portion 63 and a contact hole portion 61 formed in the interlayer insulating layer 78, and a wiring layer 62 formed in the interlayer insulating layer 77. ＲＳＴ The first source / drain region 51C (floating diffusion layer FD) is connected to one of the source / drain regions 51C.

[0038] Amplifying transistor TR ＡＭＰ The gate portion 52 is connected to the second electrode 12 via a wiring layer 62 and a wiring portion 60, and is also connected to the reset transistor TR ＲＳＴ The source / drain region 52B is connected to one of the source / drain regions 51C (floating diffusion layer FD) of the reset transistor TR ＲＳＴ The source / drain region 51B is connected to the power supply V ＤＤ (See FIG. 6).

[0039] Selection transistor TR ＳＥＬ The transistor TR is composed of a gate portion 53, a channel forming region 53A, and source / drain regions 53B, 53C. The gate portion 53 is connected to a selection line SEL (see FIG. 6). One of the source / drain regions 53B is connected to the amplifier transistor TR ＡＭＰ The other source / drain region 53C is connected to a signal line VSL (data output line, see FIG. 6).

[0040] A transfer transistor TR made of a vertical transistor ＴＲＳ The gate of the transfer transistor TR is connected to a transfer gate line TG (see FIG. 6). ＴＲＳ is a transistor having one source / drain region corresponding to a reset transistor TR. ＲＳＴ One of the source / drain regions 51C (floating diffusion layer FD) is connected to the second electrode 12 via, for example, an amplifier (signal amplifier) ​​(see FIG. 6).

[0041] A circuit capable of accumulating charge, such as an integrating circuit, may be provided in the preceding stage of the readout circuit (circuit that performs charge-voltage conversion) configured as described above.

[0042] <Configuration of pixel of photodetector> Fig. 3 is a cross-sectional view of a pixel 2-1 of a photodetector according to Example 1 of an embodiment of the present technology. Fig. 4 is a plan view of a pixel 2-1 of a photodetector according to Example 1 of an embodiment of the present technology, viewed from above a first electrode 11.

[0043] 3 illustrates first and second carrier transport layers 14 and 15. The first carrier transport layer 14 is disposed between the first electrode 11 and the photoelectric conversion layer 13. The second carrier transport layer 15 is disposed between the photoelectric conversion layer 13 and the second electrode 12. As an example, the first electrode 11 is grounded (see FIG. 8).

[0044] The photoelectric conversion layer 13 is made of, for example, a colloidal quantum dot (QD) semiconductor that absorbs light in the SWIR band (e.g., 1000-2500 nm). Examples of colloidal quantum dot semiconductors include PbS, PbSe, PbTe, InP, InAs, InSb, CdS, CdSe, and CdTe.

[0045] For example, an organic photoelectric conversion layer can be used as the photoelectric conversion layer 13. The organic photoelectric conversion layer can be configured to be composed of a material having a bulk heterostructure containing a hole transport material and an electron transport material, i.e., a bulk hetero layer containing a hole transport material and an electron transport material. The organic photoelectric conversion layer preferably further contains an organic semiconductor material with a large absorption coefficient.

[0046] Examples of conductive materials constituting the anode electrode (positive electrode) serving as the first electrode 11 from which holes are extracted include conductive materials having a high work function (for example, φ=4.5 eV to 5.5 eV), and specific examples include gold (Au), silver (Ag), chromium (Cr), nickel (Ni), palladium (Pd), platinum (Pt), iron (Fe), iridium (Ir), germanium (Ge), osmium (Os), rhenium (Re), and tellurium (Te).

[0047] The cathode electrode (negative electrode) serving as the second electrode 12 from which electrons are extracted can be made of a conductive material having a low work function (for example, φ=3.5 eV to 4.5 eV). Specific examples of such a conductive material include alkali metals (for example, Li, Na, K, etc.) and their fluorides or oxides, alkaline earth metals (for example, Mg, Ca, etc.) and their fluorides or oxides, aluminum (Al), zinc (Zn), tin (Sn), thallium (Tl), sodium-potassium alloys, aluminum-lithium alloys, magnesium-silver alloys, indium, rare earth metals such as ytterbium, and alloys thereof.

[0048] Examples of materials constituting the first electrode 11 and / or the second electrode 12 include metals such as platinum (Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum (Al), silver (Ag), tantalum (Ta), tungsten (W), copper (Cu), titanium (Ti), indium (In), tin (Sn), iron (Fe), cobalt (Co), and molybdenum (Mo), as well as alloys containing these metal elements, conductive particles made of these metals, conductive particles of alloys containing these metals, polysilicon containing impurities, carbon-based materials, oxide semiconductors, carbon nanotubes, and graphene. Furthermore, examples of materials constituting the first electrode 11 and / or the second electrode 12 include organic materials (conductive polymers) such as poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid [PEDOT / PSS]. Alternatively, these conductive materials may be mixed with a binder (polymer) to form a paste or ink, which may then be hardened and used as an electrode. The electrode may also have a structure in which two or more layers made of different materials are laminated.

[0049] A transparent conductive material can also be used as the material for forming the first electrode 11 and / or the second electrode 12. Examples of the transparent conductive material include conductive metal oxides, specifically indium oxide, indium tin oxide (ITO), Sn-doped In ２ O ３ , including crystalline ITO and amorphous ITO), indium-zinc oxide (IZO, Indium Zinc Oxide) in which indium is added as a dopant to zinc oxide, indium-gallium oxide (IGO) in which indium is added as a dopant to gallium oxide, and indium-gallium-zinc oxide (IGZO, In-GaZnO) in which indium and gallium are added as dopants to zinc oxide. ４ ), IFO (F-doped In ２ O ３ ), tin oxide (SnO ２ ), ATO (Sb-doped SnO ２ ), FTO (F-doped SnO２ ), zinc oxide (including ZnO doped with other elements), aluminum-zinc oxide (AZO) in which aluminum is added as a dopant to zinc oxide, gallium-zinc oxide (GZO) in which gallium is added as a dopant to zinc oxide, boron-zinc oxide (BZO) in which boron is added as a dopant to zinc oxide, titanium oxide (TiO ２ ), niobium-titanium oxide (TNO) in which niobium is added as a dopant to titanium oxide, antimony oxide, spinel-type oxide, YbFe ２ O ４ Examples of the transparent electrode include oxides having a structure. Further examples include transparent electrodes having a base layer made of gallium oxide, titanium oxide, niobium oxide, nickel oxide, etc. The thickness of the transparent electrode is 2×10 －８ m to 2×10 －７ m, preferably 3 × 10 －８ m to 1×10 －７ m can be mentioned.

[0050] The first carrier transport layer 14 is made of, for example, an organic material and functions specifically as a charge transport layer (charge injection blocking layer), more specifically as a hole transport layer (hole injection blocking layer). Examples of the material constituting the first carrier transport layer 14 include hole-accepting organic materials, such as fullerenes such as C60 and C70, carbon nanotubes, and derivatives thereof, oxadiazole derivatives such as 1,3-bis(4-tert-butylphenyl-1,3,4-oxadiazolyl)phenylene (OXD-7), anthraquinodimethane derivatives, diphenylquinone derivatives, bathocuproine, bathophenanthroline, and derivatives thereof, triazole derivatives, tris(8-hydroxyquinolinato)aluminum complexes, bis(4-methyl-8-quinolinato)aluminum complexes, distyrylarylene derivatives, and silole compounds. The first carrier transport layer 14 may be made of an inorganic semiconductor material such as NiO, MoOx, or n-Si.

[0051] The second carrier transport layer 15 is made of, for example, an organic material, and specifically functions as a charge transport layer (charge injection blocking layer), more specifically as an electron transport layer (electron injection blocking layer). The second carrier transport layer 15 is made of, for example, a material having a naphthalene diimide (NDI) structure (or a naphthalene-1,4,5,8-tetracarboxylic diimide structure), specifically, naphthalene-1,4,5,8-tetracarboxylic diimide. The LUMO value of the material constituting the second carrier transport layer 15 is deeper than -3.9 eV, and the HOMO value is deeper than -6.2 eV. Specifically, the LUMO value of the material constituting the second carrier transport layer 15 (naphthalene-1,4,5,8-tetracarboxylic diimide) is -4.8 eV, and the HOMO value is -7.9 eV. The second carrier transport layer 15 may be made of, for example, TiO ２ Inorganic semiconductor materials such as ZnO and p-Si can also be used.

[0052] The first electrode 11 has an opening 11a corresponding to at least one pixel 2-1. Here, the shape of the opening 11a (more specifically, the shape in a plan view) is rectangular (oblong) (see FIG. 4). That is, here, the shape of the opening 11a is two-fold symmetric and anisotropic. As an example, the first electrode 11 has a circular shape in a plan view, and more specifically, for example, a rectangular frame shape in a plan view.

[0053] The first carrier transport layer 14 has another opening 14a corresponding to the opening 11a. That is, the another opening 14a overlaps the opening 11a entirely or partially when viewed from the light incident side. Here, the another opening 14a has the same shape and size as the opening 11a, but may have a different shape and / or size. Here, the inner circumferential edge of the first carrier transport layer 14 coincides with the inner circumferential edge of the first electrode 11, but may be misaligned. A portion (lower portion) of the protective layer 82 extends into the opening 11a and the another opening 14a. For example, the first carrier transport layer 14 has a circular shape in a planar view, and more specifically, a rectangular frame shape in a planar view. By forming the another opening 14a in the first carrier transport layer 14, absorption of incident light in the first carrier transport layer 14 can be suppressed.

[0054] The second carrier transport layer 15 covers the second electrode 12 arranged on the insulating layer 110 from above and from the sides.

[0055] The ratio of the area of ​​the opening 11a to the area of ​​the pixel 2-1 (hereinafter also referred to as the "opening area ratio") is preferably 0.18 or more and 0.95 or less, more preferably 0.20 or more and 0.95 or less, more preferably 0.25 or more and 0.95 or less, more preferably 0.30 or more and 0.95 or less, more preferably 0.35 or more and 0.95 or less, and more preferably 0.40 or more and 0.95 or less.

[0056] When viewed from the light incident side (upper side), the first and second electrodes 11 and 12 have an overlapping portion, and the area of ​​the overlapping portion is preferably smaller than the area of ​​the opening 11a.

[0057] The first electrode 11 has a light-shielding property, for example, and is made of at least one of the above-mentioned metals.

[0058] 5 is a cross-sectional view of pixel 2C1 of the photodetector according to Comparative Example 1. As shown in Fig. 5, pixel 2C1 has the same configuration as pixel 2-1 of the photodetector according to Example 1, except that openings are not provided in first electrode 11C and first carrier transport layer 14C. In pixel 2C1, components corresponding to those of pixel 2-1 are assigned reference numerals obtained by adding a C to the reference numerals of the components of pixel 2-1.

[0059] It has been found that the light absorption rate in the photoelectric conversion layer 13 of pixel 2-1 of the photodetector device according to Example 1 is improved by up to 50% or more, with the light absorption rate in the photoelectric conversion layer 13C of pixel 2C1 of the photodetector device according to Comparative Example 1 being taken as the reference (1.0).

[0060] By setting the aperture area ratio to be between 0.20 and 0.95, pixel 2-1 of the photodetector according to Example 1 can have a higher light absorption rate in the photoelectric conversion layer than pixel 2C1 of the photodetector according to Comparative Example 1. In more detail, when the aperture area ratio is between 0.20 and 0.41, the light absorption rate in photoelectric conversion layer 13 of pixel 2-1 increases monotonically with an increase in the aperture area ratio, and when the aperture area ratio is between 0.41 and 0.95, the light absorption rate levels off near a maximum value (for example, a value of 1.5 or more).

[0061] <<Operation of the Photodetector>> The operation of the photodetector according to the first embodiment will now be described with reference to FIG. 6 . As shown in FIG. 6 , a voltage is applied between the first electrode 11 and the second electrode 12. Light from an object (incident light) is focused by an on-chip lens serving as a light-focusing structure 90 toward the opening in the first electrode, passes through the opening, and is incident on the photoelectric conversion layer 13. At this time, the photoelectric conversion layer 13 performs photoelectric conversion. Carriers (signal charges, e.g., electrons) generated in the photoelectric conversion layer 13 are driven by an electric field to reach the second electrode 12. The carriers that have reached the second electrode 12 are sent to the processing substrate 200 via the wiring unit 60. The processing substrate 200 performs analog signal processing (readout operation) on the carriers.

[0062] <<Method of Manufacturing Photodetector>> A method of manufacturing the semiconductor device according to the first embodiment will be described below with reference to the flowchart of Fig. 7. Here, the method of manufacturing the pixel substrate 100 of the semiconductor device according to the first embodiment will be mainly described.

[0063] In the first step S1, the wiring portion 60 is formed. Specifically, first, a base layer including an insulating layer 110 is prepared (see FIG. 8A). Note that, for simplicity, only the insulating layer 110 of the base layer is illustrated, and the insulating layer 110 is treated as a single layer. The insulating layer 110 can be formed, for example, by plasma-enhanced chemical vapor deposition (PE-CVD) or atomic layer deposition (ALD). Next, a hole H2 (through hole) is formed in the insulating layer 110 by, for example, photolithography and etching (see FIG. 8B). Finally, the wiring portion 60 is formed in the hole H2 by, for example, lift-off (see FIG. 8C). Note that, for simplicity, the wiring portion 60 is treated as a single wire. The wiring portion 60 can be formed using either a dry method or a wet method. Examples of dry methods include physical vapor deposition (PVD) and chemical vapor deposition (CVD). Examples of film formation methods using the principles of PVD include vacuum deposition using resistance heating or high-frequency heating, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, RF-DC coupled bias sputtering, ECR sputtering, facing target sputtering, and high-frequency sputtering), ion plating, laser ablation, molecular beam epitaxy, and laser transfer. Examples of CVD methods include plasma CVD, thermal CVD, metal organic (MO) CVD, and photo-CVD. Examples of wet methods include spin coating, spray coating, stamping, microcontact printing, screen printing, inkjet printing, offset printing, gravure printing, flexographic printing, and dipping. Alternatively, the surface of the second electrode 12 may be treated with oxygen plasma, argon plasma, nitrogen plasma, ozone, or the like.Examples of the patterning method include chemical etching such as shadow masking, laser transfer, and photolithography, and physical etching using ultraviolet light or a laser, etc. Techniques that can be used to planarize the first electrode and the second electrode include laser planarization, reflow, and CMP (Chemical Mechanical Polishing).

[0064] In the next step S2, the second electrode 12 is formed (see FIG. 9A ). Specifically, the second electrode 12 is formed on the insulating film 110 by, for example, lift-off. The method for forming the second electrode 12 can be the same as the method for forming the wiring portion 60 described above.

[0065] In the next step S3, the second carrier transport layer 15 is formed on the second electrode 12 and the insulating layer 110 (see FIG. 9B). The second carrier transport layer 15 can be formed by a dry film formation method or a wet film formation method. Examples of dry film formation methods include vacuum deposition using resistance heating, high-frequency heating, or electron beam heating, flash deposition, plasma deposition, EB deposition, various sputtering methods (two-pole sputtering, DC sputtering, DC magnetron sputtering, high-frequency sputtering, magnetron sputtering, RF-DC combined bias sputtering, ECR sputtering, facing target sputtering, high-frequency sputtering, and ion beam sputtering), DC (direct current) deposition, RF deposition, multi-cathode deposition, activation reaction deposition, field deposition, various ion plating methods such as high-frequency ion plating and reactive ion plating, laser ablation, molecular beam epitaxy, laser transfer deposition, and molecular beam epitaxy (MBE). Examples of CVD methods include plasma CVD, thermal CVD, MOCVD, and photo-CVD. On the other hand, specific examples of coating methods include spin coating, dipping, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, stamping, spraying, and various coating methods such as air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calendar coater. In addition, in the coating method, examples of solvents include nonpolar or low-polarity organic solvents such as toluene, chloroform, hexane, and ethanol, but are not limited to these. Examples of patterning methods include chemical etching such as shadow masking, laser transfer, and photolithography, and physical etching using ultraviolet rays or lasers. Laser planarization, reflow, and the like can be used as a planarization technique for various organic layers.Alternatively, when integrating image pickup elements as image pickup elements constituting a solid-state image pickup device, a method of forming a pattern based on a PLD method (pulsed laser deposition method) can also be employed.

[0066] In the next step S4, the photoelectric conversion layer 13 is formed on the second carrier transport layer 15 (see FIG. 9C). The photoelectric conversion layer 13 can be formed using the method for forming the second carrier transport layer 15 described above.

[0067] In the next step S5, a film of a first carrier transport layer material 14m, which is a material for the first carrier transport layer 14, is formed on the photoelectric conversion layer 13 (see FIG. 10A ). The film formation method for the second carrier transport layer 15 described above can be used as a film formation method for the first carrier transport layer material 14m.

[0068] In the next step S6, a film of a first electrode material 11m, which is the material of the first electrode 11, is formed (see FIG. 10B ). Specifically, the first electrode material 11m is formed on the first carrier transport layer material 14m. The method for forming the first electrode material 11m may be the same as the method for forming the wiring portion 60 described above.

[0069] In the next step S7, an insulating film IF is formed as a hard mask material (see FIG. 10C). Specifically, the insulating film IF (for example, SiO ２ The insulating film IF can be formed by the method for forming the insulating layer 110 described above.

[0070] In the next step S8, a resist pattern RP is formed as an etching mask (see FIG. 11A ). Specifically, a resist for forming a hard mask is applied onto the insulating film IF, and the resist pattern RP is formed by photolithography to cover regions of the insulating film IF corresponding to regions where the first electrode 11 and the first carrier transport layer 14 are to be formed.

[0071] In the next step S9, a hard mask HM is formed (see FIG. 11B). Specifically, the insulating film IF is etched using the resist pattern RP as a mask, thereby forming the hard mask HM.

[0072] In the next step S10, the first electrode 11 is formed (see FIG. 12A). Specifically, the first electrode material 11m and the first carrier transport layer material 14m (see FIG. 11B) are etched using the hard mask HM as a mask, thereby forming the first electrode 11 and the first carrier transport layer 14.

[0073] In the next step S11, the protective layer 82 is formed (see FIG. 12B). Specifically, the protective layer 82 is formed on the entire surface. The protective layer 82 can be formed using the same method as that for forming the insulating layer 110 described above.

[0074] In the next step S12, an on-chip lens is formed as the light-collecting structure 90. Specifically, for example, the on-chip lens is formed as the light-collecting structure 90 on the protective layer 82 by etch-back (see FIG. 13A). Thereafter, a protective film 91 is formed on the on-chip lens as the light-collecting structure 90 (see FIG. 13B). The protective film 91 can be formed using the same method as that for forming the insulating layer 110 described above.

[0075] 14 is a cross-sectional view of pixel 2C2 of the photodetector according to Comparative Example 2. As shown in Fig. 14, pixel 2C2 has the same configuration as pixel 2-1 of the photodetector according to Example 1, except that no openings are provided in first electrode 11C and first carrier transport layer 14C, and second electrode 12C is small. In pixel 2C2, components corresponding to those of pixel 2-1 are assigned reference numerals obtained by adding a C to the reference numerals of the corresponding components of pixel 2-1.

[0076] [Photodetector according to Example 2] Fig. 15 is a cross-sectional view of pixel 2-2 of a photodetector according to Example 2 of an embodiment of the present technology. As shown in Fig. 15, pixel 2-2 of the photodetector according to Example 2 has a configuration similar to pixel 2-1 of the photodetector according to Example 1, except that the first and second electrodes 11, 12 do not overlap when viewed from the light incident side (top side). In pixel 2-2, the area of ​​the second electrode 12 is smaller than both the area of ​​the opening 11a of the first electrode 11 and the area (opening area) of another opening 14a of the first carrier transport layer 14. Here, the second electrode 12 is disposed at the center of pixel 2-2, but may be disposed at a position shifted from the center.

[0077] 16 is a cross-sectional view of a pixel 2-3 of a photodetector according to Example 3 of an embodiment of the present technology. The pixel 2-3 of the photodetector according to Example 3 has a configuration similar to that of the pixel 2-2 of the photodetector according to Example 2, except that a guard electrode 16 (also referred to as a "guard ring") for applying voltage is provided to surround the second electrode 12, as shown in FIG. 16. In the pixel 2-3, the action of the guard electrode 16 can prevent signal charges (e.g., electrons) photoelectrically converted in the photoelectric conversion layer 13 from leaking out of the pixel 2-3, and thus the signal charges can be reliably sent to the second electrode 12.

[0078] 17 is a cross-sectional view of a pixel 2-4 of a photodetector according to Example 4 of an embodiment of the present technology. As shown in FIG. 17 , the pixel 2-4 of the photodetector according to Example 4 has a configuration similar to that of the pixel 2-3 of the photodetector according to Example 3, except that an insulating member 17 is provided between the second electrode 12 and the guard electrode 16. Here, the insulating member 17 is circumferential in plan view (e.g., frame-shaped in plan view). In the pixel 2-4, the action of the guard electrode 16 and the insulating member 17 can prevent signal charges (e.g., electrons) photoelectrically converted in the photoelectric conversion layer 13 from leaking out of the pixel 2-3, thereby ensuring that the signal charges are sent to the second electrode 12.

[0079] It has been found that under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -0.5 V), the SNR (Signal-to-Noise Ratio) is higher for the photodetector according to Example 2 compared to the photodetector according to Comparative Example 2, and is even higher for the photodetector according to Example 3 and Example 4. Even under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -1 V), the SNR is higher for the photodetector according to Example 2, and is even higher for the photodetector according to Example 3 and Example 4, although the increase in SNR is smaller than when the driving voltage is -0.5 V compared to the photodetector according to Comparative Example 2.

[0080] This is supported by the fact that, under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -0.5 V), the noise components of the photodetector according to Examples 2 to 4 are smaller than those of the photodetector according to Comparative Example 2, and are even smaller in the photodetector according to Examples 3 and 4; and that, under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -0.5 V), the signal components of the photodetector according to Examples 2 to 4 are larger than those of the photodetector according to Comparative Example 2.

[0081] In the photodetector of Example 2, under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -1 V), the noise component is almost the same as in the photodetector of Comparative Example 2, but the signal component is larger, resulting in a somewhat larger SNR.

[0082] In the photodetector of Example 3, under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -1 V), the noise component is smaller and the signal component is larger than in the photodetector of Comparative Example 2, resulting in a significantly larger SNR.

[0083] In the photodetector of Example 4, under the condition that the driving voltage applied between the first and second electrodes 11, 12 is constant (for example, -1 V), the noise component is smaller and the signal component is larger than in the photodetector of Comparative Example 2, resulting in a significantly larger SNR.

[0084] The above phenomenon has been verified by a simulation in which, for example, monochromatic light of 1450 nm is incident on each of the pixels 2-2 to 2-4, and the photocurrent / dark current (signal component / noise component) between the first and second electrodes 11 and 12 is calculated from the measurement results of an ammeter connected between the first and second electrodes 11 and 12.

[0085] 18 is a cross-sectional view of a pixel 2-5 of a photodetector according to Example 5 of an embodiment of the present technology. As shown in FIG. 18, the pixel 2-5 of the photodetector according to Example 5 has the same configuration as the pixel 2-1 of the photodetector according to Example 1, except that the pixel 2-5 does not have a separate opening 14a in the first carrier transport layer 14.

[0086] Photodetector According to Example 6 FIG. 19 is a cross-sectional view of pixel 2-6 of a photodetector according to Example 6 of an embodiment of the present technology. As shown in FIG. 19 , pixel 2-6 of the photodetector according to Example 6 has a similar configuration to pixel 2-1 of the photodetector according to Example 1, except that a light-absorbing layer 18 is provided on the light-incident side (upper side) of the first electrode 11 in the periphery of the opening 11a. The light-absorbing layer 18 is made of a material with high light absorption, such as W, metal oxide, or some organic materials. As an example, the light-absorbing layer 18 has a circular shape in a planar view, and more specifically, a rectangular frame shape in a planar view. Here, the inner circumferential edge of the light-absorbing layer 18 coincides with the inner circumferential edge of the first electrode 11, but they may be misaligned. In pixel 2-6, the light-absorbing layer 18 is provided on the first electrode 11, thereby suppressing reflection of incident light at the first electrode 11 and thereby suppressing the generation of stray light.

[0087] [Photodetector According to Example 7] FIG. 20 is a cross-sectional view of pixel 2-7 of a photodetector according to Example 7 of an embodiment of the present technology. As shown in FIG. 20 , pixel 2-7 of the photodetector according to Example 7 has a configuration similar to pixel 2-5 of the photodetector according to Example 5, except that a light-absorbing layer 18 is provided on the light-incident side (upper side) of the first electrode 11 in the area surrounding the opening 11a. The light-absorbing layer 18 is made of a material with high light absorption, such as W, metal oxide, or some organic materials. As an example, the light-absorbing layer 18 has a circular shape in a planar view, and more specifically, a rectangular frame shape in a planar view. Here, the inner circumferential edge of the light-absorbing layer 18 coincides with the inner circumferential edge of the first electrode 11, but they may be misaligned. In pixel 2-7, the light-absorbing layer 18 is provided on the first electrode 11, thereby suppressing reflection of incident light at the first electrode 11 and thereby suppressing the generation of stray light.

[0088] 21 is a cross-sectional view of a pixel 2-8 of a photodetector according to Example 8 of an embodiment of the present technology. As shown in FIG. 21 , the pixel 2-8 of the photodetector according to Example 8 has a similar configuration to the pixel 2-1 of the photodetector according to Example 1, except that the light-collecting structure 90 includes an optical element 92 (e.g., an optical filter, a polarizer, etc.) in addition to an on-chip lens.

[0089] 22 is a cross-sectional view of a pixel 2-9 of a photodetector according to Example 9 of an embodiment of the present technology. As shown in FIG. 22 , the pixel 2-9 of the photodetector according to Example 9 has the same configuration as the pixel 2-1 of the photodetector according to Example 1, except that the light-collecting structure 90 includes a Fresnel lens instead of an on-chip lens.

[0090] 23 is a cross-sectional view of a pixel 2-10 of a photodetector according to Example 10 of an embodiment of the present technology. As shown in FIG. 23 , the pixel 2-10 of the photodetector according to Example 10 has a similar configuration to the pixel 2-1 of the photodetector according to Example 1, except that the light-collecting structure 90 includes a diffractive lens instead of an on-chip lens.

[0091] 24 is a cross-sectional view of a pixel 2-11 of a photodetector according to Example 11 of an embodiment of the present technology. As shown in FIG. 24 , the pixel 2-11 of the photodetector according to Example 11 has a similar configuration to the pixel 2-1 of the photodetector according to Example 1, except that the light-collecting structure 90 includes a metalens instead of an on-chip lens.

[0092] 25 is a cross-sectional view of a pixel 2-12 of a photodetector according to a twelfth example of an embodiment of the present technology. As shown in FIG. 25, the pixel 2-12 of the photodetector according to the twelfth example has a similar configuration to the pixel 2-3 of the photodetector according to the third example, except that the pixel 2-12 has at least one (e.g., a plurality of) vias 60A, 60B that electrically connect the guard electrode 16 and the processing substrate 200. The configuration of the pixel 2-12 is effective when the guard electrode 16 is independent for each pixel.

[0093] 26 is a cross-sectional view of a pixel 2-13 of a photodetector according to Example 13 of an embodiment of the present technology. As shown in FIG. 26 , the pixel 2-13 of the photodetector according to Example 13 has a similar configuration to the pixel 2-3 of the photodetector according to Example 3, except that a via 60A electrically connecting the guard electrode 16 and the treatment substrate 200 and a via 60C penetrating the first carrier transport layer 14, the photoelectric conversion layer 13, the second carrier transport layer 15, and the insulating layer 110 and electrically connecting the first electrode 11 and the treatment substrate 200 are provided. The configuration of the pixel 2-13 is effective when both the first electrode 11 and the guard electrode 16 are independent for each pixel.

[0094] 27 is a cross-sectional view of pixel 2-14 of a photodetector according to Example 14 of an embodiment of the present technology. As shown in FIG. 27 , pixel 2-14 of the photodetector according to Example 14 has a similar configuration to pixel 2-3 of the photodetector according to Example 3, except that a via 60C is provided that penetrates the first carrier transport layer 14, the photoelectric conversion layer 13, the second carrier transport layer 15, and the insulating layer 110 and electrically connects the first electrode 11 to the processing substrate 200. The configuration of pixel 2-14 is effective when the first electrode 11 is independent for each pixel.

[0095] 3. Photodetector Devices According to Modifications 1 to 29 of an Embodiment of the Present Technology Hereinafter, several modifications of an embodiment of the present technology will be described with reference to the drawings.

[0096] [Photodetector According to Modification 1] FIG. 28 is a partial cross-sectional view of a photodetector 1001 according to Modification 1 of an embodiment of the present technology. FIG. 29 is a plan view of the first electrode 11 of the pixel array of the photodetector 1001 according to Modification 1 of an embodiment of the present technology, as viewed from above. As shown in FIGS. 28 and 29 , the photodetector 1001 according to Modification 1 has a pixel array chip on which a plurality of pixels 2-3 of the photodetector according to Example 3 are arranged in an array (one-dimensional array or two-dimensional array). In the photodetector according to Modification 1, the first electrode 11 and the guard electrode 16 are shared between the pixels 2-3, and the first electrode 11 and the guard electrode 16 extend from the pixel array region (the region where the plurality of pixels 2-3 are arranged in an array) to the chip edge (the periphery of the pixel array region), and each extending portion can be used as a terminal for applying a voltage. In this case, the above-described via is not required. Note that one of the first electrode 11 and the guard electrode 16 may be shared between the pixels 2-3. In this case, the other of the first electrode 11 and the guard electrode 16 may be electrically connected to the processing substrate 200 through a via.

[0097] Here, we have described a pixel array chip in which multiple pixels 2-3 are arranged in an array, but it is also possible to configure a pixel array chip in which multiple pixels of photodetection devices according to other embodiments are arranged in an array in a similar manner.

[0098] [Photodetector according to Modification 2] Fig. 30 is a plan view seen from above the first electrode 11 of a pixel array of a photodetector 1002 according to Modification 2 of an embodiment of the present technology. As shown in Fig. 30 , the photodetector 1002 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1002, the first electrode 11 has an opening 11a corresponding to each pixel 2. Here, the shape of each opening 11a in the first electrode 11 has n-fold symmetry (n is an integer greater than or equal to 2), and more specifically, is a square. The example of Fig. 30 shows that an on-chip lens serving as a light-collecting structure 90 is provided for each pixel.

[0099] 31A is a plan view of a pixel array of a photodetector 1003 according to a third modification of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 31A , the photodetector 1003 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1003, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 has n-fold symmetry (n is an integer of 2 or more), and more specifically, is a circle or an ellipse.

[0100] 31B is a plan view of a pixel array of a photodetector 1004 according to a fourth modification of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 31B , the photodetector 1004 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1004, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 has n-fold symmetry (n is an integer of 2 or more), and more specifically, is a polygon (e.g., a regular octagon).

[0101] [Photodetector According to Modification 5] FIG. 32A is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector 1005 according to Modification 5 of an embodiment of the present technology. As shown in FIG. 32A , the photodetector 1005 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1005, the first electrode 11 has one opening 11a corresponding to a plurality of pixels 2 (e.g., all pixels 2). In the photodetector 1005, the first electrode 11 has electrode portions 11p arranged at each corner of each pixel 2. The electrode portions 11p other than the electrode portions 11p arranged at the corners of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2 or four adjacent pixels 2). In other words, the electrode portion 11p is shared between at least two pixels 2 whose corners are adjacent to each other. The electrode portion 11p spanning the at least two pixels 2 is located at a position including the adjacent corners of the at least two pixels 2.

[0102] [Photodetector According to Modification 6] FIG. 32B is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector 1006 according to Modification 6 of an embodiment of the present technology. As shown in FIG. 32B , the photodetector 1006 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1006, the first electrode 11 has an opening 11a corresponding to each pixel 2. In the photodetector 1006, the first electrode 11 has an elongated electrode portion 11p extending along each edge of each pixel 2. The electrode portions 11p other than the electrode portion 11p arranged on the outer periphery of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2). In other words, the electrode portion 11p is shared between at least two pixels 2 whose edges are adjacent to each other. The electrode portion 11p spanning the at least two pixels 2 is located at a position including the adjacent edges of the at least two pixels 2.

[0103] [Photodetector Device According to Modification 7] Fig. 32C is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector device 1007 according to Modification 7 of an embodiment of the present technology. As shown in Fig. 32C, the photodetector device 1007 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector device 1007, the first electrode 11 has an opening 11a corresponding to each pixel 2. In the photodetector device 1007, the first electrode 11 has an elongated electrode portion 11p extending along each edge of each pixel 2. Some of the electrode portions 11p span at least two pixels 2 (e.g., two adjacent pixels 2 or four adjacent pixels 2). In other words, the electrode portion 11p is shared between at least two pixels 2 whose edges and corners are adjacent to each other. The electrode portion 11p spanning the at least two pixels 2 is located at a position including the adjacent edges and adjacent corners of each of the at least two pixels 2.

[0104] 33A is a plan view of a pixel array of a photodetector 1008 according to Modification 8 of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 33A , the photodetector 1008 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1008, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 is n-fold symmetric (n is an integer greater than or equal to 2), and more specifically, is an asterisk shape.

[0105] 33B is a plan view of a pixel array of a photodetector 1009 according to a 9th modification of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 33B , the photodetector 1009 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1009, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 is n-fold symmetric (n is an integer greater than or equal to 2), and more specifically, is H-shaped.

[0106] 33C is a plan view of a pixel array of a photodetector 1010 according to a tenth modification of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 33C , the photodetector 1010 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1010, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 has n-fold symmetry (n is an integer greater than or equal to 2), and more specifically, is concave.

[0107] 33D is a plan view of a pixel array of a photodetector 1011 according to Modification 11 of an embodiment of the present technology, viewed from above a first electrode 11. As shown in FIG. 33D , the photodetector 1011 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1011, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, the shape of each opening 11 a in the first electrode 11 is n-fold symmetric (n is an integer greater than or equal to 2), and more specifically, is a four-lobe shape.

[0108] [Photodetector According to Modification 12] Fig. 34A is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector 1012 according to Modification 12 of an embodiment of the present technology. As shown in Fig. 34A , the photodetector 1012 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1012, the first electrode 11 has openings 11a corresponding to a plurality of pixels 2 (e.g., all of the pixels 2). In the photodetector 1012, the first electrode 11 has elongated electrode portions 11p extending in a direction intersecting (specifically, perpendicular to) each edge of each pixel 2 and passing through the center of the pixel 2. The electrode portions 11p other than the electrode portions 11p arranged on the periphery of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2). In other words, the electrode portions 11p are shared between at least two pixels 2 whose edges are adjacent to each other. The electrode portion 11p spanning the at least two pixels 2 is located at a position including a part of the edges of the at least two pixels 2 adjacent to each other.

[0109] [Photodetector Device According to Modification 13] Fig. 34B is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector device 1013 according to Modification 13 of an embodiment of the present technology. As shown in Fig. 34B , the photodetector device 1013 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector device 1013, the first electrode 11 has openings 11a corresponding to a plurality of pixels 2 (e.g., all of the pixels 2). In the photodetector device 1013, the first electrode 11 has elongated first electrode portions 11p1 extending in a direction intersecting (more specifically, perpendicular to) each edge of each pixel 2 and passing through the center of the pixel 2, and second electrode portions 11p2 arranged at positions including each corner of each pixel 2. The first electrode portions 11p1 other than the first electrode portions 11p1 arranged on the periphery of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2). That is, the first electrode portion 11p1 is shared between at least two pixels 2 whose edges are adjacent to each other. The first electrode portion 11p1 spanning the at least two pixels 2 is located at a position that includes a portion of each of the adjacent edges of the at least two pixels 2. The second electrode portion 11p2 other than the second electrode portion 11p2 arranged at the corner of the pixel array spans at least two pixels 2 (for example, two adjacent pixels 2 or four adjacent pixels 2). That is, the second electrode portion 11p2 is shared between at least two pixels 2 whose corners are adjacent to each other. The second electrode portion 11p2 spanning the at least two pixels 2 is located at a position that includes each of the adjacent corners of the at least two pixels 2.

[0110] [Photodetector Device According to Modification 14] Fig. 34C is a plan view seen from above on a first electrode 11 of a pixel array of a photodetector device 1014 according to Modification 14 of an embodiment of the present technology. As shown in Fig. 34C, the photodetector device 1014 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector device 1014, the first electrode 11 has openings 11a corresponding to a plurality of pixels 2 (e.g., all of the pixels 2). In the photodetector device 1014, the first electrode 11 has electrode portions 11p at positions including each corner of each pixel 2, the electrode portions 11p including a first portion extending in a direction intersecting an edge of the pixel 2 and passing through the center of the pixel 2, and a second portion extending in a direction intersecting (e.g., perpendicular to) the first portion. The electrode portions 11p other than the electrode portions 11p arranged at the corners of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2 or four adjacent pixels 2). That is, the electrode portion 11p is shared between at least two pixels 2 whose corners are adjacent to each other. The electrode portion 11p spanning the at least two pixels 2 is located at a position including the mutually adjacent corners of the at least two pixels 2.

[0111] 35A is a plan view seen from above the first electrode 11 of a pixel array of a photodetector 1015 according to a modification 15 of an embodiment of the present technology. As shown in FIG. 35A , the photodetector 1015 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, in a matrix). In the photodetector 1015, the first electrode 11 has openings 11 a corresponding to each pixel 2. Here, for example, on-chip lenses as the light-collecting structure 90 correspond to 2 × 2 (=4) pixels 2.

[0112] 35B is a plan view of a pixel array of a photodetector 1016 according to a modification 16 of an embodiment of the present technology, as viewed from above the first electrode 11. As shown in FIG. 35B , the photodetector 1016 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, in a matrix). In the photodetector 1016, the first electrode 11 has an opening 11a corresponding to each pixel 2. Here, for example, some on-chip lenses 90A correspond to one pixel 2, and other on-chip lenses 90B correspond to 2×1 (=two) pixels 2.

[0113] 36A is a plan view seen from above the first electrode 11 of a pixel array of a photodetector 1017 according to a modification 17 of an embodiment of the present technology. As shown in FIG. 36A , the photodetector 1017 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1017, the first electrode 11 has first openings 11a1 corresponding to some of the pixels 2 and second openings 11a2 corresponding to half pixels of the other pixels 2. This makes it possible to detect an image plane phase difference.

[0114] [Photodetector according to Modification 18] Fig. 36B is a plan view seen from above the first electrode 11 of a pixel array of a photodetector 1018 according to Modification 18 of an embodiment of the present technology. As shown in Fig. 36B , the photodetector 1018 has a pixel array in which a plurality of pixels 2 having an anisotropic shape (e.g., rectangular) are arranged in a two-dimensional array (e.g., matrix). In the photodetector 1018, the first electrode 11 has openings 11a corresponding to each pixel 2. The openings 11a have an anisotropic shape (e.g., ellipse, rectangle, etc.) according to the shape of the pixel 2. Here, for example, on-chip lenses serving as the light-collecting structure 90 correspond to two adjacent pixels 2.

[0115] [Photodetector According to Modification 19] Fig. 37A is a plan view of a pixel array of a photodetector 1019 according to Modification 19 of an embodiment of the present technology, viewed from above a first electrode 11. As shown in Fig. 37A , the photodetector 1019 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1019, the first electrode 11 has openings 11a corresponding to a plurality of pixels 2 (e.g., four adjacent pixels 2). Here, the shape of each opening 11a is n-fold symmetric (n is an integer greater than or equal to 2), specifically, a tetralobe shape. Here, for example, on-chip lenses serving as light-collecting structures 90 correspond to four adjacent pixels 2 that share the openings 11a.

[0116] [Photodetector According to Modification 20] Fig. 37B is a plan view of a pixel array of a photodetector 1020 according to Modification 20 of an embodiment of the present technology, viewed from above a first electrode 11. As shown in Fig. 37B , the photodetector 1020 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1020, the first electrode 11 has openings 11a corresponding to each pixel 2. Here, the shape of each opening 11a is n-fold symmetric (n is an integer greater than or equal to 2), and more specifically, is H-shaped. Here, for example, an on-chip lens serving as a light-collecting structure 90 corresponds to each pixel 2.

[0117] [Photodetector according to Modification 21] Fig. 38 is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1021 according to Modification 21 of an embodiment of the present technology. As shown in Fig. 38 , the photodetector 1021 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, in a matrix). In the photodetector 1021, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel 2 has n-fold symmetry (n is an integer of 2 or more), and more specifically, is circular or elliptical.

[0118] [Photodetector according to Modification 22] Fig. 39A is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1022 according to Modification 22 of an embodiment of the present technology. As shown in Fig. 39A , the photodetector 1022 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1022, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel is n-fold symmetric (n is an integer of 2 or more), and more specifically, is circular or elliptical. The guard electrode 16 has a convoluted (e.g., frame-shaped) electrode portion 16p surrounding each second electrode 12.

[0119] [Photodetector according to Modification 23] Fig. 39B is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1023 according to Modification 23 of an embodiment of the present technology. As shown in Fig. 39B , the photodetector 1023 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1023, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel 2 is n-fold symmetric (n is an integer greater than or equal to 2), specifically, circular or elliptical, and the guard electrode 16 has electrode portions 16p arranged at each corner of the pixel 2 so as to surround the corresponding second electrode 12. The electrode portions 16p other than the electrode portions 16p arranged at the corners of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2 or four adjacent pixels 2). In other words, the electrode portions 16p are shared between at least two pixels 2 whose corners are adjacent to each other. The electrode portion 16p spanning the at least two pixels 2 is located at a position including the mutually adjacent corners of each of the at least two pixels 2.

[0120] [Photodetector According to Modification 24] Fig. 39C is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1024 according to Modification 24 of an embodiment of the present technology. As shown in Fig. 39C , the photodetector 1024 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1024, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel 2 is n-fold symmetric (n is an integer greater than or equal to 2), specifically, circular or elliptical. The guard electrode 16 has elongated electrode portions 16p arranged along each edge of the pixel 2 so as to surround the corresponding second electrode 12. The electrode portions 16p other than the electrode portions 16p arranged on the outer periphery of the pixel array span at least two pixels 2 (e.g., two adjacent pixels 2). In other words, the electrode portions 16p are shared between at least two pixels 2 whose edges are adjacent to each other. The electrode portion 16p spanning the at least two pixels 2 is located at a position including the edges of the at least two pixels 2 adjacent to each other.

[0121] 40 is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1025 according to Modification 25 of an embodiment of the present technology. As shown in FIG. 40 , the photodetector 1025 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (e.g., a matrix). In the photodetector 1025, a second electrode 12 and an insulating member 17 are provided for each pixel 2. The shape of the second electrode 12 of each pixel is n-fold symmetric (n is an integer of 2 or more), specifically, circular or elliptical. The shape of the insulating member 17 is, for example, circular or elliptical and concentric with the second electrode 12 surrounding the corresponding second electrode 12. The guard electrode 16 has a circumferential (e.g., frame-shaped) electrode portion 16p surrounding each insulating member 17.

[0122] 41A is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1026 according to Modification 26 of an embodiment of the present technology. As shown in FIG. 41A , the photodetector 1026 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1026, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel has n-fold symmetry (n is an integer greater than or equal to 2), and more specifically, is a four-lobe shape.

[0123] 41B is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1027 according to Modification 27 of an embodiment of the present technology. As shown in FIG. 41B , the photodetector 1027 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1027, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel has n-fold symmetry (n is an integer of 2 or more), and more specifically, is an asterisk shape.

[0124] 41C is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1028 according to Modification 28 of an embodiment of the present technology. As shown in FIG. 41C , the photodetector 1028 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, a matrix). In the photodetector 1028, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel has n-fold symmetry (n is an integer greater than or equal to 2), and more specifically, is X-shaped.

[0125] 41D is a plan view seen from below the second electrode 12 of a pixel array of a photodetector 1029 according to Modification 29 of an embodiment of the present technology. As shown in FIG. 41D , the photodetector 1029 has a pixel array in which a plurality of pixels 2 are arranged in a two-dimensional array (for example, in a matrix). In the photodetector 1029, a second electrode 12 is provided for each pixel 2. The shape of the second electrode 12 of each pixel has n-fold symmetry (n is an integer greater than or equal to 2), and more specifically, is H-shaped.

[0126] Fig. 42A is a diagram for explaining an example in which the first electrode 11 and the second electrode 12 do not overlap when viewed from the light incident side. Fig. 42B is a diagram for explaining an example in which the first electrode 11 and the second electrode 12 overlap when viewed from the light incident side. Fig. 43A is a diagram showing dark current paths in the example of Fig. 42A. Fig. 43B is a diagram showing dark current paths in the example of Fig. 42B.

[0127] In the example of Fig. 42A , the dark current path (the black portion in Fig. 43A ) is narrowed as shown in Fig. 43A , and it can be seen that the dark current suppression effect is high. On the other hand, in the example of Fig. 42B , the dark current path (the black portion in Fig. 43B ) is widened as can be seen from Fig. 43B . In this case, in order to enhance the dark current suppression effect, it is preferable that the area of ​​the opening 11 a of the first electrode 11 (the area of ​​the light black portion in Fig. 42B ) is larger than the area of ​​the overlapping portion between the first electrode 11 and the second electrode 12 (the area of ​​the dark black portion in Fig. 42B ).

[0128] 44A is a partial cross-sectional view of a pixel array including pixel 2-3 of a photodetector according to Example 3 of an embodiment of the present technology. FIG. 44B is a perspective view of a pixel array including pixel 2-3 of a photodetector according to Example 3 of an embodiment of the present technology. Note that a pixel array may also be configured in which any of the pixels of the photodetector according to Examples 1, 2, and 4 to 14 or any of the pixels of the photodetector according to Modifications 1 to 29 are two-dimensionally arranged. In either case, the first electrode 11 may be provided independently (separately) for each pixel 2, or may be provided in common (integrally) between at least two pixels 2.

[0129] As shown in Figure 45A, the first electrode 11 and the first carrier transport layer 14 may be provided in a semi-embedded state in the photoelectric conversion layer 13, as in pixel 2-M1 of variant example 1 of the photodetector device according to one embodiment of the present technology.

[0130] As shown in pixel 2-M2 of modified example 2 of the photodetector according to an embodiment of the present technology shown in Figure 45B, the first electrode 11 and the first carrier transport layer 14 may be provided in a semi-embedded state in the photoelectric conversion layer 13, and a light absorption layer 18 may be provided on the first electrode 11.

[0131] As in a pixel 2-M3 of a third modification of a photodetector according to an embodiment of the present technology shown in FIG. 46A, the first electrode 11 may be provided in a semi-buried state in the first carrier transport layer 14.

[0132] As shown in FIG. 46B , as in pixel 2-M4 of modified example 4 of the photodetector according to an embodiment of the present technology, the first electrode 11 may be provided in a semi-embedded state in the first carrier transport layer 14, and a light absorption layer 18 may be provided on the first electrode 11.

[0133] 4. Effects of the Photodetection Device According to an Embodiment of the Present Technology The effects of the photodetection device according to an embodiment and modification of the present technology will be described below.

[0134] A photodetector according to one embodiment (each example and each variant example) of the present technology comprises a pixel substrate 100 having at least one pixel 2, in which at least a first electrode 11, a photoelectric conversion layer 13, and a second electrode 12 are stacked in this order from the light incident side, and the pixel substrate 100 has at least one pixel 2, and the first electrode 11 has an opening 11a corresponding to the at least one pixel 2.

[0135] According to the photodetector of one embodiment, incident light can be incident on the photoelectric conversion layer 13 through the opening 11a of the first electrode 11. Therefore, compared to a case where a solid transparent electrode is provided as the first electrode, it is possible to suppress attenuation of incident light before it reaches the photoelectric conversion layer 13, and as a result, it is possible to suppress a decrease in light absorption in the photoelectric conversion layer 13. This can improve the EQE.

[0136] In the photodetector according to one embodiment, a transparent electrode is not essential, so there is no concern about a decrease in yield due to instability in the transparent electrode formation process.

[0137] The photodetector device according to one embodiment can reduce the dark current without reducing the photocurrent, thereby improving the EQE while increasing the SNR.

[0138] The photodetector according to an embodiment provides greater freedom in selecting the material for the first electrode 11. For example, the material for the first electrode 11 can be a metal or a conductive oxide (not limited to a transparent electrode).

[0139] The photodetector according to one embodiment can improve the degree of freedom in the shape and arrangement of the opening of the first electrode 11, and thus can improve the degree of freedom in design for improving characteristics. The shape of the opening of the first electrode 11 may be a circle, an ellipse, a polygon, an X-shape, an H-shape, a four-lobe shape, a star shape, a concave shape, or a shape obtained by rotating any of these shapes.

[0140] In the photodetector device according to the embodiment, the second electrode 12 is preferably disposed at the center of the pixel. The shape of the second electrode 12 may be a circle, an ellipse, a polygon, an X-shape, an H-shape, a four-lobe shape, a star shape, a concave shape, or a shape obtained by rotating any of these shapes.

[0141] In one embodiment of the photodetector, by using colloidal quantum dots (PbS, PbSe, PbTe, InP, InAs, InSb, CdS, CdSe, CdTe, etc.) that absorb light with wavelengths in the SWIR band (e.g., 1000-2500 nm) in the photoelectric conversion layer 13, it is possible to realize a photodetector that is sensitive to the SWIR band.

[0142] In the photodetector according to the embodiment, at least one pixel 2 may have an anisotropic shape such as a rectangle or an ellipse. This allows the pixel 2 to perform image plane phase difference detection.

[0143] The pixel substrate 100 preferably has a first carrier transport layer 14 disposed between the first electrode 11 and the photoelectric conversion layer 13. The first carrier transport layer 14 may or may not have another opening 14a corresponding to the opening 11a of the first electrode 11.

[0144] In the pixel substrate 100 , a second carrier transport layer 15 is preferably disposed between the second electrode 12 and the photoelectric conversion layer 13 .

[0145] The ratio of the area of ​​the opening 11a of the first electrode 11 to the area of ​​at least one pixel 2 is preferably 0.18 to 0.95. The opening width (diameter) of the opening 11a is preferably at least half the wavelength of the incident light to be detected.

[0146] A light absorbing layer 18 may be provided on the light incident side surface of the first electrode 11 in the periphery of the opening 11a, thereby making it possible to suppress the occurrence of stray light (flare light and ghost light).

[0147] When viewed from the light incident side, the first and second electrodes 11 and 12 do not need to overlap.

[0148] When viewed from the light incident side, the first and second electrodes 11 and 12 may have an overlapping portion. In this case, the area of ​​the overlapping portion is preferably smaller than the area of ​​the opening 11a.

[0149] The first electrode 11 may have a light-blocking property (light-absorbing property, light-reflecting property, etc.).

[0150] The shape of the opening 11a may be n-fold symmetric (n≧2).

[0151] The shape of the opening 11a may be anisotropic.

[0152] The opening 11a may correspond to half of one pixel 2. That is, half of the pixel 2 may be shielded from light. This makes it possible to detect an image plane phase difference.

[0153] When at least one pixel 2 is a plurality of pixels arranged in a two-dimensional array, the first electrode 11 may have a portion that spans at least two of the plurality of pixels 2. The spanning portion may span all of the plurality of pixels 2.

[0154] At least two pixels 2 may have adjacent edges, and the straddling portion may be located at a position that includes at least a part of each of the adjacent edges of the at least two pixels 2 .

[0155] At least two pixels 2 may have corners adjacent to each other, and the straddling portion may be located at a position including the corners of the at least two pixels 2 adjacent to each other.

[0156] At least two pixels 2 may have adjacent edges and corners, and the first electrode 11 may have the spanning portion located at a position that includes at least a portion of the adjacent edges of each of the at least two pixels 2, and the spanning portion located at a position that includes the adjacent corners of each of the at least two pixels 2.

[0157] The spanning portion may extend in a direction passing through the centers of at least two pixels.

[0158] It is preferable to further include a light-collecting structure 90 that is arranged on the light incident side of the pixel substrate 100 and corresponds to at least two of the plurality of pixels 2. The light-collecting structure 90 may include, for example, an on-chip lens, a metalens, a diffractive lens, or the like, or may include a polarizer, a wavelength filter, or the like. The light-collecting structure 90 may be provided across the plurality of pixels 2. This makes it possible to detect an image plane phase difference.

[0159] The photodetection device of one embodiment further includes a processing substrate 200 on the opposite side of the light incident side of the pixel substrate 100, and may be provided with a via 60C (through via) that penetrates at least the photoelectric conversion layer 13 and electrically connects the first electrode 11 and the processing substrate 200.

[0160] The first electrode 11 may be electrically connected to a power source at the chip end of the pixel chip or pixel array chip.

[0161] The second electrode 12 may be electrically connected to a power source at the chip end of the pixel chip or pixel array chip.

[0162] The second electrode 12 may be electrically connected to the processing substrate 200 via a wiring portion 60 (for example, a through via).

[0163] A circuit that performs charge-voltage conversion, such as an SF circuit (source follower circuit), may be connected to the second electrode 12. A circuit that can accumulate charge, such as an integrating circuit, may be provided in a stage preceding the circuit that performs charge-voltage conversion.

[0164] A guard electrode 16 for applying a voltage may be provided to surround the second electrode 12. The guard electrode 16 may be provided so as to surround the periphery of the second electrode 12 for charge recovery. The voltage applied to the guard electrode 16 may be at the same potential as the second electrode 12 for charge recovery, and it is preferable that the guard electrode 16 is not connected to a circuit for charge recovery but is connected for voltage application.

[0165] In the pixel array, guard electrodes 16 may be disposed between adjacent pixels 2 .

[0166] An insulating member 17 may be provided between the second electrode 12 and the guard electrode 16. This makes it possible to further electrically separate the second electrode 12 and the guard electrode 16.

[0167] The above-described photodetector device can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, and other devices with imaging functions.

[0168] 5. Configuration Example of Photodetector Mounted on Electronic Device FIG. 47 is a block diagram showing a configuration example of a photodetector mounted on electronic device.

[0169] As shown in FIG. 47, the photodetector 101 includes an optical system 102, a photodetector element 103, and a DSP (Digital Signal Processor) 104. The DSP 104, a display device 105, an operation system 106, a memory 108, a recording device 109, and a power supply system 111 are connected via a bus 107, and the photodetector 101 is capable of capturing still and moving images.

[0170] The optical system 102 is configured to have one or more lenses, and guides image light (incident light) from a subject to the photodetector element 103 , forming an image on the light receiving surface (sensor portion) of the photodetector element 103 .

[0171] The photodetector element 103 may be any of the photodetector elements according to the above-described embodiments or modifications. Electrons are accumulated in the photodetector element 103 for a certain period of time in accordance with an image formed on the light-receiving surface via the optical system 102. A signal corresponding to the electrons accumulated in the photodetector element 103 is then supplied to the DSP 104.

[0172] The DSP 104 performs various signal processing on the signal from the photodetector element 103 to acquire an image, and temporarily stores the image data in the memory 108. The image data stored in the memory 108 is recorded in the recording device 109 or supplied to the display device 105 to display the image. In addition, the operation system 106 accepts various operations by the user and supplies operation signals to each block of the photodetector device 101, and the power supply system 111 supplies the power necessary to drive each block of the photodetector device 101.

[0173] 6. Light Detection System Using a Light Detection Device FIG. 48A is a schematic diagram illustrating an example of the overall configuration of a light detection system 2000 including a light detection device. FIG. 48B is a diagram illustrating an example of the circuit configuration of the light detection system 2000. The light detection system 2000 includes a light-emitting device 2001 serving as a light source unit that emits infrared light L2 and a light detection device 2002 serving as a light-receiving unit having a photoelectric conversion element. The light detection device 1 described above can be used as the light detection device 2002. The light detection system 2000 may further include a system control unit 2003, a light source driving unit 2004, a sensor control unit 2005, a light source-side optical system 2006, and a camera-side optical system 2007. The light detection device 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by a subject (measurement target) 2100. Light L2 is light emitted by the light-emitting device 2001 and then reflected by the subject 2100. Light L1 is, for example, visible light, and light L2 is, for example, infrared light. Light L1 can be detected by a photoelectric conversion unit in the photodetector 2002, and light L2 can be detected by a photoelectric conversion unit in the photodetector 2002. Image information of the subject 2100 can be obtained from light L1, and distance information between the subject 2100 and the photodetection system 2000 can be obtained from light L2. The photodetection system 2000 can be mounted on, for example, an electronic device such as a smartphone or a mobile object such as a car. The light-emitting device 2001 can be configured, for example, with a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can be, for example, an iTOF method, but is not limited thereto. In the iTOF method, the photoelectric conversion unit can measure the distance to the subject 2100 by, for example, time-of-flight (TOF). As a method for detecting the light L2 emitted from the light emitting device 2001 by the photodetector 2002, for example, a structured light method or a stereo vision method can also be adopted.For example, in the structured light method, a predetermined pattern of light is projected onto the subject 2100, and the distortion of the pattern is analyzed to measure the distance between the light detection system 2000 and the subject 2100. In addition, in the stereo vision method, for example, two or more cameras are used to acquire two or more images of the subject 2100 viewed from two or more different viewpoints, thereby measuring the distance between the light detection system 2000 and the subject. Note that the light emitting device 2001 and the light detection device 2002 can be synchronously controlled by a system control unit 2003.

[0174] 7. Other Modifications of the Present Technology The configuration of the photodetector and the like described above can be modified as appropriate. For example, the pixel 2 may have an intra-pixel light-shielding film. This makes it possible to detect an image plane phase difference. For example, when the pixel substrate 100 has a plurality of pixels 2, the pixel substrate 100 may have an inter-pixel light-shielding film and / or an intra-pixel light-shielding film.

[0175] For example, when the photodetector 1 is used for imaging, the photoelectric conversion layer 13 may absorb light in the visible light band (RGB). In this case, the photodetector 1 may have an on-chip color filter and / or an on-chip lens.

[0176] The shape of the on-chip lens may be other than a hemisphere, and may be, for example, a shape in which the four corners are filled in when viewed from above from the light incident side.

[0177] For example, the photodetector 1 may have a memory chip, a logic chip, an analog chip, an interface chip, an AI chip, etc. integrated with the pixel substrate 100 and the processing substrate 200 .

[0178] For example, the configurations of the photodetector devices of the above-described embodiments and modifications may be combined with each other within a range that does not cause technical contradictions.

[0179] The numerical values, materials, shapes, dimensions, etc. used in the description of the above embodiments and modifications are merely examples and are not intended to limit the scope of the invention.

[0180] 8. Usage Example of Photodetection Device to which the Present Technology is Applied> FIG. 49 is a diagram showing a usage example in which the photodetection device according to the present technology (for example, the photodetection devices according to the embodiments and modifications) constitutes a solid-state imaging device (image sensor).

[0181] The above-described embodiments can be used in various cases where light such as visible light, infrared light, ultraviolet light, and X-rays is sensed, for example, as shown in Fig. 49. That is, as shown in Fig. 49, the embodiments can be used in devices used in the fields of appreciation for capturing images for viewing, transportation, home appliances, medicine and healthcare, security, beauty, sports, agriculture, etc.

[0182] Specifically, in the field of appreciation, the light detection device according to the present technology can be used in devices for capturing images for appreciation, such as digital cameras, smartphones, and mobile phones with camera functions.

[0183] In the field of transportation, for example, the optical detection device according to the present technology can be used in devices used for transportation, such as in-vehicle sensors that capture images of the front, rear, surroundings, interior, etc. of a vehicle for safe driving such as automatic stopping, or for recognizing the driver's condition, surveillance cameras that monitor moving vehicles and roads, and distance measurement sensors that measure distances between vehicles, etc.

[0184] In the field of home appliances, for example, the photodetector according to the present technology can be used in devices provided in home appliances such as television sets, refrigerators, and air conditioners to capture user gestures and operate the appliances in accordance with the gestures.

[0185] In the medical and healthcare fields, the light detection device according to the present technology can be used in devices used for medical and healthcare purposes, such as endoscopes and devices that perform angiography by receiving infrared light.

[0186] In the field of security, for example, the photodetector according to the present technology can be used in devices used for security purposes, such as surveillance cameras for crime prevention and cameras for person authentication.

[0187] In the field of beauty, for example, the light detection device according to the present technology can be used in devices used for beauty, such as a skin measuring device that takes pictures of the skin and a microscope that takes pictures of the scalp.

[0188] In the field of sports, for example, the light detection device according to the present technology can be used in devices used for sports, such as action cameras and wearable cameras for sports applications.

[0189] In the field of agriculture, for example, the photodetector according to the present technology can be used in devices used in agriculture, such as cameras for monitoring the conditions of fields and crops.

[0190] Next, specific examples of use of the photodetector according to the present technology (e.g., the photodetector according to each embodiment and each modified example) will be described. For example, the photodetector according to each embodiment and each modified example described above can be applied as a solid-state imaging device 501 to any type of electronic device equipped with an imaging function, such as a camera system such as a digital still camera or a video camera, or a mobile phone with an imaging function. FIG. 50 shows a schematic configuration of an electronic device 510 (camera) as an example. This electronic device 510 is, for example, a video camera capable of capturing still images or videos, and includes a solid-state imaging device 501, an optical system (optical lens) 502, a shutter device 503, a driver 504 that drives the solid-state imaging device 501 and the shutter device 503, and a signal processor 505.

[0191] The optical system 502 guides image light (incident light) from the subject to the pixel region of the solid-state imaging device 501. This optical system 502 may be composed of a plurality of optical lenses. The shutter device 503 controls the light irradiation period and light blocking period of the solid-state imaging device 501. The drive unit 504 controls the transfer operation of the solid-state imaging device 501 and the shutter operation of the shutter device 503. The signal processing unit 505 performs various signal processing on the signal output from the solid-state imaging device 501. The video signal Dout after signal processing is stored in a storage medium such as a memory, or is output to a monitor, etc.

[0192] 9. Other Use Examples of Photodetection Devices to which the Present Technology is Applied The photodetection device according to the present technology (e.g., the photodetection devices according to the embodiments and modifications) can also be applied to other electronic devices that detect light, such as a TOF (Time of Flight) sensor. When applied to a TOF sensor, the present technology can be applied to, for example, a range image sensor using a direct TOF measurement method or a range image sensor using an indirect TOF measurement method. In a range image sensor using the direct TOF measurement method, the arrival timing of photons is directly determined in the time domain at each pixel, so a light pulse with a short pulse width is transmitted and an electrical pulse is generated by a receiver with high response speed. The present disclosure can be applied to the receiver in such a case. Furthermore, in the indirect TOF method, the time of flight of light is measured using a semiconductor element structure in which the detection and accumulation amount of carriers generated by light changes depending on the arrival timing of light. The present disclosure can also be applied to such a semiconductor structure. When applied to a TOF sensor, providing an on-chip color filter or an on-chip lens is optional and is not necessary.

[0193] 10. Application Examples to Mobile Bodies, etc. 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, or on a low-power device, such as a smartphone, a smartwatch, a tablet, or a mouse.

[0194] FIG. 51 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.

[0195] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 51, 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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 inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0202] 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.

[0203] 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.

[0204] 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. 51, 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.

[0205] FIG. 52 is a diagram showing an example of the installation position of the imaging unit 12031.

[0206] In FIG. 52 , a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as an imaging unit 12031.

[0207] 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 forward images acquired by the imaging units 12101 and 12105 are mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0208] 52 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.

[0209] 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.

[0210] 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 closest three-dimensional object on the path of the vehicle 12100 that is traveling or stopped at a predetermined speed (e.g., 0 km / h or higher) in approximately the same direction as the vehicle 12100. 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 runs autonomously without relying on driver operation.

[0211] 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.

[0212] 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.

[0213] An example of a vehicle control system to which the technology according to the present disclosure (the present technology) can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the image capturing unit 12031 among the above-described configurations. Specifically, the light detection device 1 according to the present disclosure can be applied to the image capturing unit 12031. Applying the technology according to the present disclosure to the image capturing unit 12031 can improve yield and reduce manufacturing costs.

[0214] 11. Application Example to Endoscopic Surgery System The present technology can be applied to various products. For example, the technology according to the present disclosure (the present technology) may be applied to an endoscopic surgery system.

[0215] FIG. 53 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.

[0216] Figure 53 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.

[0217] 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.

[0218] 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.

[0219] 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 by the optical system onto the image sensor. 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.

[0220] 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.

[0221] 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.

[0222] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing the surgical site, etc.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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 in a narrower band than the light irradiated during normal observation (i.e., white light) to capture high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, in what is 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 tissues (autofluorescence observation), or may involve locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissues 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.

[0228] FIG. 54 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0229] 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.

[0230] 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.

[0231] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be a single (so-called single-chip type) or multiple (so-called multi-chip type). When the imaging unit 11402 is composed of 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 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 composed of a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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 .

[0238] 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.

[0239] 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.

[0240] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] The above describes an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the endoscope 11100, the camera head 11102 (the imaging unit 11402), and the like, among the above-described configurations. Specifically, the light detection device 1 according to the present disclosure can be applied to the imaging unit 10402. By applying the technology according to the present disclosure to the endoscope 11100, the camera head 11102 (the imaging unit 11402), and the like, it is possible to improve yield and reduce manufacturing costs.

[0246] Here, an endoscopic surgery system has been described as an example, but the technology according to the present disclosure may also be applied to other systems, such as a microsurgery system.

[0247] The present technology may also be configured as follows. (1) A photodetector including a pixel substrate having at least one pixel, the pixel substrate including at least a first electrode, a photoelectric conversion layer, and a second electrode stacked in this order from a light incident side, the pixel substrate including the at least one pixel, the first electrode having an opening corresponding to the at least one pixel. (2) The photodetector according to (1), wherein the pixel substrate includes a carrier transport layer disposed between the first electrode and the photoelectric conversion layer. (3) The photodetector according to (2), wherein the carrier transport layer has another opening corresponding to the opening. (4) The photodetector according to any one of (1) to (3), wherein a ratio of an area of ​​the opening to an area of ​​the at least one pixel is 0.20 to 0.95. (5) The photodetector according to any one of (1) to (4), wherein a light absorption layer is provided on a surface of the first electrode on the light incident side in a portion surrounding the opening. (6) The photodetector according to any one of (1) to (5), wherein the first and second electrodes do not overlap when viewed from the light incident side. (7) The photodetector according to any one of (1) to (6), wherein the first and second electrodes have an overlapping portion when viewed from the light incident side, and the area of ​​the overlapping portion is smaller than the area of ​​the opening. (8) The photodetector according to any one of (1) to (7), wherein the first electrode has light-blocking properties. (9) The photodetector according to any one of (1) to (8), wherein the shape of the opening has n-fold symmetry (n≧2). (10) The photodetector according to any one of (1) to (9), wherein the shape of the opening is anisotropic. (11) The photodetector according to any one of (1) to (10), wherein the opening corresponds to half of the pixel. (12) The photodetector according to any one of (1) to (11), wherein the at least one pixel is a plurality of pixels arranged in a two-dimensional array, and the first electrode has a portion spanning at least two of the plurality of pixels. (13) The photodetector according to (12), wherein the spanning portion spans all of the plurality of pixels. (14) The photodetector according to (12) or (13), wherein the at least two pixels have adjacent edges, and the spanning portion is located at a position including the adjacent edges of the at least two pixels.(15) The photodetector according to any one of (12) to (14), wherein corners of the at least two pixels are adjacent to each other, and the spanning portion is located at a position including the adjacent corners of the at least two pixels. (16) The photodetector according to any one of (12) to (15), wherein edges and corners of the at least two pixels are adjacent to each other, and the first electrode has: the spanning portion located at a position including the adjacent edges of the at least two pixels; and the spanning portion located at a position including the adjacent corners of the at least two pixels. (17) The photodetector according to any one of (12) to (16), wherein the spanning portion extends in a direction passing through centers of the at least two pixels. (18) The photodetector according to any one of (1) to (17), further comprising a light-collecting structure disposed on the light incident side of the pixel substrate and corresponding to at least one of the pixels. (19) The photodetector according to any one of (1) to (18), further comprising a processing substrate arranged on the opposite side of the pixel substrate from the light incident side, wherein a via is provided that penetrates at least the photoelectric conversion layer and electrically connects the first electrode and the processing substrate. (20) The photodetector according to any one of (1) to (19), wherein a guard electrode for applying a voltage is provided and surrounds the second electrode. (21) The photodetector according to any one of (1) to (20), wherein an insulating member is provided between the second electrode and the guard electrode. (22) The photodetector according to any one of (1) to (21), wherein the pixel substrate has another carrier transport layer arranged between the second electrode and the photoelectric conversion layer.

[0248] 1: Photodetector 2, 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, 2-9, 2-10, 2-11, 2-12, 2-13, 2-14, 2-M1, 2-M2, 2-M3, 2-M4: Pixel 11: First electrode 11a: Opening 12: Second electrode 13: Photoelectric conversion layer 14: First carrier transport layer 14a: Another opening 15: Second carrier transport layer 16: Guard electrode 17: Insulating member 18: Light absorption layer 60C: Via 90: Light collection structure 100: Pixel substrate 200: Processing substrate

Claims

1. A photodetector comprising a pixel substrate having at least one pixel, in which at least a first electrode, a photoelectric conversion layer, and a second electrode are stacked in this order from the light incident side, and the first electrode has an opening corresponding to the at least one pixel.

2. The photodetector according to claim 1, wherein the pixel substrate has a carrier transport layer disposed between the first electrode and the photoelectric conversion layer.

3. The photodetector device according to claim 2, wherein the carrier transport layer has another opening corresponding to the opening.

4. The photodetector device according to claim 1, wherein the ratio of the area of said opening to the area of said at least one pixel is between 0.20 and 0.

95.

5. The photodetector according to claim 1, wherein a light absorbing layer is provided on the light incident side surface of the first electrode in the peripheral portion of the opening.

6. The photodetector device according to claim 1, wherein the first and second electrodes do not overlap when viewed from the light incident side.

7. The photodetector according to claim 1, wherein when viewed from the light incident side, the first and second electrodes have an overlapping portion, and the area of the overlapping portion is smaller than the area of the opening.

8. The photodetector according to claim 1, wherein the first electrode has a light-shielding property.

9. The photodetector device according to claim 1, wherein the shape of the opening has n-fold symmetry (n≧2).

10. The optical detection device according to claim 1, wherein the shape of the opening is anisotropic.

11. The photodetector device according to claim 1, wherein the opening corresponds to half of the pixel.

12. The photodetector device according to claim 1, wherein the at least one pixel is a plurality of pixels arranged in a two-dimensional array, and the first electrode has a portion that spans at least two of the plurality of pixels.

13. The photodetector device according to claim 12, wherein the spanning portion spans all of the plurality of pixels.

14. The photodetection device according to claim 12, wherein the at least two pixels have adjacent edges, and the spanning portion is located at a position that includes at least a part of the adjacent edges of each of the at least two pixels.

15. The photodetection device according to claim 12, wherein the at least two pixels have corners adjacent to each other, and the spanning portion is located at a position including the adjacent corners of each of the at least two pixels.

16. The photodetector device of claim 12, wherein the at least two pixels have adjacent edges and corners, and the first electrode has: the spanning portion located at a position that includes at least a part of the adjacent edges of each of the at least two pixels; and the spanning portion located at a position that includes the adjacent corners of each of the at least two pixels.

17. The photodetector device according to claim 12, wherein the spanning portion extends in a direction passing through the centers of the at least two pixels.

18. The photodetector device according to claim 1, further comprising a light-collecting structure disposed on the light-incident side of the pixel substrate and corresponding to at least one of the pixels.

19. The photodetector according to claim 1, further comprising a processing substrate disposed on the opposite side of the pixel substrate from the light incident side, and having a via that penetrates at least the photoelectric conversion layer and electrically connects the first electrode and the processing substrate.

20. The photodetector according to claim 1, further comprising a guard electrode for applying a voltage that surrounds the second electrode.

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