Light detection device

Abstract

A light detection device comprises a pixel disposed on a substrate, the pixel having a photoelectric conversion layer that generates an electric charge by incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface opposite to the light incident surface of the photoelectric conversion layer, the lower electrode having a protruding electrode extending toward the photoelectric conversion layer in the thickness direction of the photoelectric conversion layer, and the protruding electrode being provided along the inner periphery of the lower electrode in a plan view of the substrate and including a reflective material that reflects incident light.

Description

Photodetector

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

[0002] The photodetector has a photoelectric conversion unit formed of, for example, a PN junction photodiode. The photoelectric conversion unit mainly includes a photoelectric conversion layer that generates charges in response to incident light, and an upper electrode and a lower electrode that sandwich the photoelectric conversion layer. Such a photodetector is disclosed, for example, in Patent Document 1 listed below.

[0003] JP 2018-98438 A

[0004] In recent years, there has been a strong demand for photodetectors to further improve photoelectric conversion efficiency and more reliably suppress color mixing, but in the prior art, the lower electrode of the photoelectric conversion unit has not been thoroughly studied with the aim of further improving the various characteristics of such photodetectors.

[0005] Therefore, in the present disclosure, the above-mentioned lower electrode has been thoroughly studied, and a new and improved photodetector capable of further improving the characteristics of the photodetector is provided.

[0006] According to the present disclosure, there is provided a photodetection device comprising pixels arranged on a substrate, the pixels having a photoelectric conversion layer that generates charges in response to incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, the lower electrode having a protruding electrode extending in the thickness direction of the photoelectric conversion layer to the photoelectric conversion layer, the protruding electrode being provided along the inner periphery of the lower electrode in a planar view of the substrate, and including a reflective material that reflects the incident light.

[0007] Furthermore, according to the present disclosure, there is provided a photodetection device comprising a plurality of pixels arranged in a matrix on a substrate, each pixel having a photoelectric conversion layer that generates electric charges in response to incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, the lower electrode having a protruding electrode extending to the photoelectric conversion layer in the thickness direction of the photoelectric conversion layer, the protruding electrode being provided along the inner periphery of the lower electrode in a planar view of the substrate, at least the side of the protruding electrode facing an adjacent pixel being covered with an insulating layer, and the lower electrode and the protruding electrode being formed from a transparent conductive material.

[0008] 1 is a block diagram illustrating an overall configuration of a photodetection device according to an embodiment of the present disclosure. FIG. 2 is an equivalent circuit diagram of each unit pixel of the photodetection device shown in FIG. 1. FIG. 3 is a cross-sectional view schematically illustrating the configuration of each unit pixel of the photodetection device shown in FIG. 1. FIG. 4 is a cross-sectional view schematically illustrating the configuration of each unit pixel of the photodetection device according to the first embodiment. FIG. 5 is a cross-sectional view and a plan view schematically illustrating the configuration of a lower electrode shown in FIG. 4. FIG. 6 is a cross-sectional view schematically illustrating the configuration of each unit pixel of the photodetection device according to the second embodiment. FIG. 7 is a plan view schematically illustrating the configuration of a lower electrode shown in FIG. 6. FIG. 8 is a cross-sectional view (part 1) for explaining an effect achieved by a pixel according to the second embodiment. FIG. 9 is a cross-sectional view (part 2) for explaining an effect achieved by a pixel according to the second embodiment. FIG. 10 is a cross-sectional view (part 3) for explaining an effect achieved by a pixel according to the second embodiment. FIG. 11 is a plan view (part 4) for explaining an effect achieved by a pixel according to the second embodiment. FIG. 12 is a plan view (part 1) for explaining the configuration of a columnar electrode according to a modification of the second embodiment. FIG. 13 is a plan view (part 2) for explaining the configuration of a columnar electrode according to a modification of the second embodiment. FIG. 14 is a cross-sectional view schematically illustrating the configuration of two adjacent pixels of a photodetection device according to a third embodiment. 16 is a plan view showing the configuration of each unit pixel of the photodetection device shown in FIG. 14. FIG. 17 is a cross-sectional view (part 1) showing the configuration of each unit pixel of the photodetection device according to the fourth embodiment. FIG. 18 is a cross-sectional view (part 2) showing the configuration of two adjacent pixels of the photodetection device according to the fourth embodiment. FIG. 19 is a cross-sectional view (part 2) showing the configuration of two adjacent pixels of the photodetection device according to the fifth embodiment. FIG. 20 is a cross-sectional view (part 2) showing the configuration of two adjacent pixels of the photodetection device according to a modification of the fifth embodiment. FIG. 21 is a cross-sectional view (part 2) showing the configuration of two adjacent pixels of the photodetection device according to the sixth embodiment. FIG. 22 is a cross-sectional view and a plan view showing the configuration of two adjacent pixels of the photodetection device according to a modification of the sixth embodiment. FIG. 23 is a cross-sectional view and a plan view showing the configuration of two adjacent pixels of the photodetection device according to the seventh embodiment. FIG. 24 is a flow diagram showing a method for manufacturing pixels according to the first embodiment. FIG. 25 is a block diagram showing an example of the configuration of an electronic device. FIG. 26 is a schematic view showing an example of the overall configuration of a photodetection system. FIG. 27 is a diagram showing an example of the circuit configuration of the photodetection system shown in FIG. 26. FIG. 28 is a block diagram showing an example of the general configuration of a vehicle control system.The present invention relates to an endoscopic surgery system, and more particularly to an endoscopic surgery apparatus, a surgical instrument, and a CCU, and is an explanatory diagram illustrating an example of the installation positions of a vehicle exterior information detection unit and an imaging unit.

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted. Furthermore, in this specification and the drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding different letters after the same reference numeral. However, when there is no particular need to distinguish between multiple components having substantially the same or similar functional configurations, only the same reference numerals will be used.

[0010] The drawings referred to in the following description are for explaining and facilitating understanding of one embodiment of the present disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from the actual ones. Furthermore, the design of the devices shown in the drawings can be modified as appropriate, taking into consideration the following description and known technologies.

[0011] The description of a specific shape in the following description does not mean only a geometrically defined shape, but more specifically, the description of a shape in the following description also includes shapes that have allowable differences (errors and distortions) in the photodetector, its manufacturing process, and its use and operation, as well as shapes similar to those shapes.

[0012] The description will be given in the following order: 1. Example of schematic configuration of a light detection device 2. Embodiments 2-1. First embodiment 2-2. Second embodiment 2-3. Third embodiment 2-4. Fourth embodiment 2-5. Fifth embodiment 2-6. Sixth embodiment 2-7. Seventh embodiment 3. Flow of manufacturing method 4. Example of application to electronic devices 5. Example of application to a light detection system 6. Example of application to a moving object 7. Example of application to an endoscopic surgery system

[0013] (1. Schematic Configuration Example of Photodetection Device) First, with reference to FIG. 1 , the overall configuration of a photodetection device 1 according to an embodiment of the present disclosure will be described. FIG. 1 is a block diagram illustrating the overall configuration of a photodetection device 1 according to an embodiment of the present disclosure. The illustrated photodetection device 1 can be used as a solid-state imaging device. The photodetection device 1 includes a pixel region (so-called imaging region) 3 in which pixels 2, each including a plurality of photoelectric conversion elements, are regularly arranged two-dimensionally (e.g., arranged in a matrix) on a semiconductor substrate 70 (e.g., a silicon substrate), and a peripheral circuit unit. Each pixel 2 includes, for example, a photodiode serving as a photoelectric conversion element, and a plurality of pixel transistors (so-called MOS (Metal-Oxide-Semiconductor) transistors). The plurality of pixel transistors can be configured with, for example, three transistors: a transfer transistor, a reset transistor, and an amplification transistor. Alternatively, the plurality of pixel transistors can be configured with four transistors by adding a selection transistor. The pixel 2 can also have a shared pixel structure. The pixel sharing structure is composed of, for example, a plurality of photodiodes, a plurality of transfer transistors, one floating diffusion shared by these photodiodes, and a group of pixel transistors shared by these photodiodes.

[0014] As shown in FIG. 1, 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.

[0015] 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 operations of the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. The control circuit 8 then inputs these signals to the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc.

[0016] The vertical drive circuit 4 is configured by, for example, a shift register, selects a pixel drive wiring, supplies a pulse to the selected pixel drive wiring for driving the pixels 2, and drives the pixels 2 row by row. That is, the vertical drive circuit 4 selects and scans each pixel 2 in the pixel region 3 row by row in the vertical direction, and supplies a pixel signal based on a signal charge generated in accordance with the amount of light received in, for example, a photodiode serving as a photoelectric conversion element of each pixel 2 to the column signal processing circuit 5 via the vertical signal line 9.

[0017] The column signal processing circuit 5 is arranged, for example, for each column of pixels 2, and performs 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 circuit 5 performs signal processing such as CDS (Correlated Double Sampling) for removing fixed pattern noise specific to the pixels 2, signal amplification, and AD (Analog-Digital) conversion. A horizontal selection switch (not shown) is provided at the output stage of the column signal processing circuit 5 and connected between the output stage and the horizontal signal line 10.

[0018] 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.

[0019] The output circuit 7 processes and outputs signals sequentially supplied from each of the column signal processing circuits 5 through 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 80 exchanges signals with the outside.

[0020] Next, an example of the circuit configuration of the pixel 2 will be described with reference to Fig. 2. Fig. 2 is an equivalent circuit diagram of each unit pixel 2 of the photodetector 1 shown in Fig. 1.

[0021] As shown in FIG. 2, the pixel 2 includes a photoelectric conversion unit (photodiode) and a charge storage unit (floating diffusion) FD that temporarily stores the charge output from the photoelectric conversion unit. １ It has the following features.

[0022] The photoelectric conversion unit is made up of, for example, a PN junction photodiode, and performs photoelectric conversion to generate charges according to the amount of light received. In detail, the photoelectric conversion unit is made up of a stacked structure of a photoelectric conversion layer 13 that generates charges in response to incident light, an upper electrode 12 provided on the light incident surface side of the photoelectric conversion layer 13, and a lower electrode 11 provided on the surface opposite to the light incident surface of the photoelectric conversion layer 13. The lower electrode 11 is connected to the pixel transistor and the charge storage unit FD. １ The upper electrode 12 is connected to the reference potential line V ＯＵ is connected to.

[0023] Furthermore, the pixel 2 has, as pixel transistors, for example, a reset transistor TR1rst, an amplification transistor TR1amp, and a selection transistor TR1sel.

[0024] One of the source / drain regions of the reset transistor TR1rst is connected to the charge storage unit FD １ The other of the source and drain regions of the reset transistor TR1rst is electrically connected to the power supply line V ＤＤ The gate of the amplifier transistor TR1amp is electrically connected to one of the source / drain regions of the reset transistor TR1rst and the charge storage unit FD １ The other of the source / drain regions of the selection transistor TR1sel is connected to the signal line VSL １ is electrically connected to

[0025] The reset transistor TR1rst is connected to the charge storage unit FD １ In detail, when the reset transistor TR1rst is turned on, the potential of the charge storage unit FD １ The potential of the power line V ＤＤ The selection transistor TR1sel controls the output timing of the pixel signal. The amplification transistor TR1amp resets the potential of the charge storage unit FD１ In detail, when the selection transistor TR1sel is turned on, the amplification transistor TR1amp generates a pixel signal according to the level of the charge stored in the charge storage unit FD １ A voltage corresponding to the level of the charge stored in the signal line VSL is output as a pixel signal. １ The signal is output to the column signal processing circuit 5 via the .

[0026] In the embodiment of the present disclosure, the equivalent circuit of the pixel 2 is not limited to the circuit shown in FIG.

[0027] FIG. 3 is a cross-sectional schematic diagram illustrating the configuration of each unit pixel 2 of the photodetector 1 shown in FIG. 1 . As shown in FIG. 3 , the pixel 2 is provided on a semiconductor substrate (more specifically, a silicon semiconductor layer) 70. In FIG. 3 , the light incident surface of the semiconductor substrate 70 is positioned upward. The pixel 2 has a photoelectric conversion unit (photodiode) disposed above the semiconductor substrate 70. The photoelectric conversion unit is a stacked structure including a photoelectric conversion layer 13 that generates charge in response to incident light, an upper electrode 12 disposed on the light incident surface 13A side of the photoelectric conversion layer 13, and a lower electrode 11 disposed on the surface 13B of the photoelectric conversion layer 13 opposite the light incident surface 13A. The lower electrode 11 is connected to the pixel transistor and charge storage unit 51C disposed below the photoelectric conversion layer 13.

[0028] A wiring layer 73 is provided between the photoelectric conversion unit and the semiconductor substrate 70. Vias 61 and 64 and wirings 62 and 63 that connect to the lower electrode 11 are provided in the wiring layer 73. These vias 61 and 64 and wirings 62 and 63 are connected to the pixel transistors and charge accumulation unit 51C provided on the semiconductor substrate 70.

[0029] 3, a charge storage unit 51C and an amplification transistor TR1amp are provided on the semiconductor substrate 70, and the lower electrode 11 is connected to the charge storage unit 51C and the gate unit 52 of the amplification transistor TR1amp. The charge storage unit 51C stores charges generated in the photoelectric conversion layer 13. Furthermore, the semiconductor substrate 70 is provided with a reset transistor TR1rst and a selection transistor TR1sel.

[0030] The charge storage portion 51C is connected to one of the source / drain regions of the reset transistor TR1rst by sharing the same region. The other of the source / drain regions 51B of the reset transistor TR1rst is connected to the power supply line V ＤＤ The other source / drain region 52C of the amplification transistor TR1amp is connected to one of the source / drain regions of the selection transistor TR1sel by sharing the same region. The other source / drain region 51B of the amplification transistor TR1amp is connected to the power supply line V ＤＤ Furthermore, the other of the source and drain regions 53C of the selection transistor TR1sel is connected to a signal line VSL1.

[0031] Furthermore, an element isolation region 71 is formed on the first surface (front surface) 70A side of the semiconductor substrate 70 to isolate the pixel transistors. Also, an oxide film 72 that serves as the gate electrodes of the pixel transistors is formed on the first surface 70A of the semiconductor substrate 70.

[0032] In the pixel 2, a planarization film 82 is formed above the upper electrode 12, and an on-chip lens 90 is provided on the planarization film 82. The planarization film 82 is made of, for example, silicon oxide (SiO ２ ), silicon nitride (Si ３ N ４ ), aluminum oxide (Al ２ O ３ ) etc.

[0033] (2. Embodiments) Each embodiment of the present disclosure described below was created based on a study of the lower electrode 11 of the pixel 2 in order to further improve various characteristics of the photodetector 1. The embodiments of the present disclosure will be described below in order. Note that in each embodiment described below, the photodetector 1 has one pixel 2 arranged on a semiconductor substrate 70, or a plurality of pixels 2 arranged in a matrix on the semiconductor substrate 70.

[0034] (2-1. First Embodiment) First, the first embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a schematic cross-sectional view showing the configuration of each unit pixel 2 of the photodetector 1 according to the first embodiment. Fig. 5 is a schematic cross-sectional view and a plan view showing the configuration of the lower electrode 11 shown in Fig. 4.

[0035] As shown in FIG. 4 , in this embodiment, the pixel 2 includes, as a photoelectric conversion unit, a photoelectric conversion layer 13 that generates charges in response to incident light, an upper electrode 12 provided on a light incident surface 13A of the photoelectric conversion layer 13, and a lower electrode 11 provided on a surface 13B of the photoelectric conversion layer 13 opposite the light incident surface 13A. Furthermore, the lower electrode 11 includes a protruding electrode 111 that extends to the photoelectric conversion layer 13 in the thickness direction of the photoelectric conversion layer 13. As shown in FIG. 5 , the protruding electrode 111 is provided along the inner periphery of the lower electrode 11 in a plan view of the semiconductor substrate 70. Specifically, the protruding electrode 111 has a frame-like shape that surrounds the center of the upper surface of the lower electrode 11. Details of each component of the pixel 2 are described below.

[0036] The lower electrode 11 is provided for each pixel 2. The lower electrode 11 includes a metal material. In this embodiment, the metal material is, for example, 10 －８ Preferably, the material has a resistance value of Ω / cm or less. Furthermore, in this embodiment, since the protruding electrode 111 and the lower electrode 11 are integrated into one body, which facilitates the fabrication of the lower electrode 11 and the protruding electrode 111, the lower electrode 11 is preferably formed from the same material as the protruding electrode 111, i.e., a reflective material. Specifically, in this embodiment, the lower electrode 11 is formed from a reflective material. The reflective material includes at least one metal species selected from the group consisting of copper (Cu), aluminum (Al), and gold (Au). Each side of the lower electrode 11 has a length of, for example, several micrometers (e.g., 1 to 9 micrometers). Furthermore, when the photodetector 1 has a plurality of pixels 2 arranged in a matrix on the semiconductor substrate 70, the distance between the lower electrodes 11 is preferably, for example, about 200 nm to prevent leakage between the pixels 2.

[0037] In this embodiment, the protruding electrode 111 includes a reflective material on at least its surface that reflects incident light. In detail, as shown in FIG. 4, in this embodiment, the protruding electrode 111 is formed of a reflective material. As described above, the reflective material includes at least one metal species selected from the group consisting of copper, aluminum, and gold. Furthermore, the reflective material is, for example, 10% or less in order to reduce the resistance of the lower electrode 11. －８ It is preferable that the material has a resistance value of Ω / cm or less. The protruding electrode 111 has a height of, for example, several hundred nanometers. Furthermore, as shown in FIG. 5 , the protruding electrode 111 preferably has a width d1 of, for example, several tens of nanometers in order to have high reflectivity for light of a predetermined wavelength. Specifically, when the protruding electrode 111 is made of copper, the width d1 of the protruding electrode 111 is preferably 50 nm or more in order to have high reflectivity for light of a wavelength of about 450 nm.

[0038] In this embodiment, a protruding electrode 111 made of a reflective material is provided along the inner periphery of the lower electrode 11. The protruding electrode 111 reflects light incident at an oblique angle to the upper surface of the lower electrode 11 (arrow L0 in FIG. 4 ) to the photoelectric conversion layer 13 on the lower electrode 11, thereby suppressing leakage of light to the outside of the pixel 2 and enabling efficient collection of light on the photoelectric conversion layer 13. Therefore, according to this embodiment, the photoelectric conversion efficiency of the photodetector 1 can be improved.

[0039] In this embodiment, as shown in Fig. 4, the outermost surfaces of the protruding electrodes 111 and the lower electrode 11 are preferably covered with a charge transport layer 14. The charge transport layer 14 is intended to promote the supply of charges generated in the photoelectric conversion layer 13 to the lower electrode 11, and is made of, for example, titanium oxide (TiO ２), zinc oxide (ZnO), an organic material, or the like. In this embodiment, the outermost surfaces of the protruding electrodes 111 and the lower electrode 11 are covered with the charge transport layer 14, thereby facilitating the supply of charges generated in the photoelectric conversion layer 13 to the lower electrode 11. Furthermore, in this embodiment, the provision of the protruding electrodes 111 increases the contact area between the photoelectric conversion layer 13 and the charge transport layer 14, thereby improving the adhesion between the photoelectric conversion layer 13 and the charge transport layer 14.

[0040] In this embodiment, the photoelectric conversion layer 13 may be provided for each pixel 2, or may be provided as a single layer across multiple pixels 2. The photoelectric conversion layer 13 can be formed from an organic material (organic photoelectric conversion film) or an inorganic material (inorganic photoelectric conversion film). For example, when the photoelectric conversion layer 13 is formed from an organic material, any one of the following four modes can be selected: (a) a P-type organic semiconductor material; (b) an N-type organic semiconductor material; (c) a stacked structure of at least two of a P-type organic semiconductor material layer, an N-type organic semiconductor material layer, and a mixed layer of a P-type organic semiconductor material and an N-type organic semiconductor material (bulk heterostructure); or (d) a mixed layer of a P-type organic semiconductor material and an N-type organic semiconductor material. The photoelectric conversion layer 13 using an organic material also includes a laminated structure such as an electron blocking film / buffer film in contact with the upper electrode 12 and the lower electrode 11, the photoelectric conversion layer 13, a hole blocking film, a hole blocking film / buffer film, and a work function adjustment film.

[0041] In particular, examples of P-type organic semiconductor materials include naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, pentacene derivatives, quinacridone derivatives, coumarin derivatives, pyrromethene derivatives, pyran derivatives, phenoxazone derivatives, thiophene derivatives, thienothiophene derivatives, benzothiophene derivatives, benzothienobenzothiophene (BTBT) derivatives, dinaphthothienothiophene (DNTT) derivatives, dianthracenothienothiophene (DATT) derivatives, benzobisbenzothiophene (BBBT) derivatives, naphthalenebisbenzothiophene (NBBT), thienobisbenzothiophene (TBBT) derivatives, and dibenzothienobisbenzothiophene. Examples of the heterocyclic compound include dithiophene (DBTBT) derivatives, dithienobenzodithiophene (DTBDT) derivatives, dibenzothienodithiophene (DBTDT) derivatives, benzodithiophene (BDT) derivatives, naphthodithiophene (NDT) derivatives, anthracenodithiophene (ADT) derivatives, tetracenodithiophene (TDT) derivatives, pentacenodithiophene (PDT) derivatives, triallylamine derivatives, carbazole derivatives, picene derivatives, chrysene derivatives, fluoranthene derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, subporphyrazine derivatives, metal complexes having a heterocyclic compound as a ligand, polythiophene derivatives, polybenzothiadiazole derivatives, and polyfluorene derivatives.

[0042] Examples of N-type organic semiconductor materials include fullerenes and fullerene derivatives (for example, fullerenes (higher fullerenes) such as C60, C70, and C74, endohedral fullerenes, etc.) or fullerene derivatives (for example, fullerene fluorides, PCBM (Phenyl-C61-Butyric Acid Methyl Ester) fullerene compounds, fullerene polymers, etc.), organic semiconductors with deeper HOMOs (Highest Occupied Molecular Orbitals) and LUMOs (Lowest Unoccupied Molecular Orbitals) than P-type organic semiconductors, and inorganic metal oxides that can transmit light. More specifically, examples of N-type organic semiconductor materials include organic molecules, organometallic complexes, and subphthalocyanine derivatives having, as part of their molecular skeletons, heterocyclic compounds containing nitrogen atoms, oxygen atoms, or sulfur atoms, such as pyridine derivatives, pyrromethene derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, isoquinoline derivatives, coumarin derivatives, pyran derivatives, phenoxazone derivatives, perylene derivatives, acridine derivatives, phenazine derivatives, phenanthroline derivatives, tetrazole derivatives, pyrazole derivatives, imidazole derivatives, thiazole derivatives, oxazole derivatives, imidazole derivatives, benzimidazole derivatives, benzotriazole derivatives, benzoxazole derivatives, carbazole derivatives, benzofuran derivatives, dibenzofuran derivatives, subporphyrazine derivatives, polyphenylenevinylene derivatives, polybenzothiadiazole derivatives, and polyfluorene derivatives.Further, examples of groups contained in the fullerene derivative include branched or cyclic alkyl or phenyl groups; groups having a linear or condensed aromatic compound; groups having a halide; partial fluoroalkyl groups; perfluoroalkyl groups; silyl alkyl groups; silyl alkoxy groups; aryl silyl groups; aryl sulfanyl groups; alkyl sulfanyl groups; aryl sulfonyl groups; alkyl sulfide groups; alkyl sulfide groups; amino groups; alkyl amino groups; aryl amino groups; hydroxy groups; alkoxy groups; acyl amino groups; acyloxy groups; carbonyl groups; carboxy groups; carboxamido groups; carboalkoxy groups; acyl groups; sulfonyl groups; cyano groups; nitro groups; groups having a chalcogenide; phosphine groups; phosphonic groups; and derivatives thereof. Further, in the above description, organic semiconductor materials are classified into P-type and N-type, but here, P-type means that they easily transport holes, and N-type means that they easily transport electrons. That is, organic semiconductor materials are not limited to the interpretation that they have holes or electrons as thermally excited majority carriers, as in inorganic semiconductor materials.

[0043] Furthermore, the photoelectric conversion layer 13 may be formed from a polymer of phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, diacetylene, or the like, or a derivative thereof.

[0044] When the photoelectric conversion layer 13 is made of an inorganic material, examples of the inorganic semiconductor material include crystalline silicon, amorphous silicon, microcrystalline silicon, crystalline selenium, amorphous selenium, and chalcopalite compounds such as CIGS (CuInGaSe) and CIS (CuInSe). ２ ), CuInS ２ , CuAlS ２ , CuAlSe ２ , CuGaS ２ , CuGaSe ２ , AgAlS ２ , AgAlSe ２ , AgInS ２ , AgInSe ２, or III-V group compounds such as GaAs, InP, AlGaAs, InGaP, AlGaInP, and InGaAsP, as well as CdSe, CdS, and In ２ Se ３ , In ２ S ３ , Bi ２ Se3, Bi ２ S ３ , ZnSe, ZnS, PbSe, PbS, etc. In addition, in this embodiment, quantum dots made of these materials can also be used as the photoelectric conversion layer 13.

[0045] Furthermore, in order to detect blue light and green light, the photoelectric conversion layer 13 can preferably use, for example, metal complex dyes, rhodamine dyes, quinacridone dyes, cyanine dyes, melacyanine dyes, phenylxanthene dyes, triphenylmethane dyes, rhodacyanine dyes, xanthene dyes, macrocyclic azaannulene dyes, azulene dyes, naphthoquinone, anthraquinone dyes, condensed polycyclic aromatic compounds such as anthracene and pyrene, and chain compounds in which aromatic rings or heterocyclic compounds are condensed, or two nitrogen-containing heterocycles such as quinoline, benzothiazole and benzoxazole having a squarylium group and a croconite methine group as a bonding chain, or cyanine-like dyes bonded by a squarylium group and a croconite methine group. Of the metal complex dyes, dithiol metal complex dyes, metal phthalocyanine dyes, metal porphyrin dyes, and ruthenium complex dyes are preferred, with ruthenium complex dyes being particularly preferred, but the invention is not limited to these.

[0046] Furthermore, in this embodiment, as described above, quantum dots can also be used as the photoelectric conversion layer 13. Quantum dots are semiconductor microparticles with a diameter (particle size) of several nanometers to approximately 10 nanometers. Specifically, quantum dots are composed of a core and a shell layer covering the surface of the core. For example, the core and shell layer can be formed from, for example, PbO, PbS, PbSe, PbTe, GaAs, InAs, InP, AlGaAs, InGaP, AlGaInP, CdS, CdSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, HgTe, or the like.

[0047] In this embodiment, the upper electrode 12 may be provided for each pixel 2, or may be provided as a single layer across a plurality of pixels 2. The upper electrode 12 may be formed of a transparent conductive film that can transmit light, such as a tin-indium oxide (including ITO, crystalline ITO, and amorphous ITO) film. However, in this embodiment, the upper electrode 12 is not limited to the ITO described above, and may be made of other materials. For example, the transparent conductive film is preferably made of a material with a band gap of 2.5 eV or more, preferably 3.1 eV or more. For example, the transparent conductive film may be made of a tin oxide-based material, such as tin oxide or antimony-tin oxide (SnO ２ Sb is added as a dopant to the fluorine-tin oxide (e.g., ATO), ２ Examples of zinc oxide-based materials include aluminum-zinc oxide (ZnO with Al added as a dopant, for example, AZO), gallium-zinc oxide (ZnO with Ga added as a dopant, for example, GZO), indium-zinc oxide (ZnO with In added as a dopant, for example, IZO), indium-gallium-zinc oxide (ZnO with In and Ga added as dopants, for example, IGZO), and indium-tin-zinc oxide (ZnO with In and Sn added as dopants, for example, ITZO). Other examples include indium-gallium oxide (Ga ２ O ３ Adding In as a dopant, for example, IGO or CuInO ２, MgIn ２ O ４ , CuI, InSbO ４ , ZnMgO, CdO, ZnSnO ３ , graphene, etc.

[0048] In this embodiment, for example, an on-chip lens 90 is further provided above the upper electrode 12 for each pixel 2. The on-chip lens 90 may be provided for each pixel 2. The on-chip lens 90 may be made of, for example, Si ３ N ４ Alternatively, it can be formed from a resin material such as a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, or a siloxane resin.

[0049] As described above, in this embodiment, the protruding electrode 111 made of a reflective material is provided along the inner periphery of the lower electrode 11. The protruding electrode 111 reflects light incident at an oblique angle to the upper surface of the lower electrode 11 to the photoelectric conversion layer 13 on the lower electrode 11, thereby suppressing leakage of light to the outside of the pixel 2 and enabling efficient collection of light to the photoelectric conversion layer 13. Therefore, according to this embodiment, the photoelectric conversion efficiency of the photodetector 1 can be improved. In other words, according to this embodiment, the characteristics of the photodetector 1 can be further improved.

[0050] The configuration of this embodiment is not limited to the configuration examples shown in FIGS.

[0051] (2-2. Second Embodiment) Next, a second embodiment will be described with reference to Fig. 6 to Fig. 11. Fig. 6 is a cross-sectional view showing the configuration of each unit pixel 2 of a photodetector 1 according to the second embodiment, and Fig. 7 is a plan view showing the configuration of the lower electrode 11 shown in Fig. 6. Furthermore, Figs. 8 to 11 are cross-sectional views showing the effects of the pixel 2 according to this embodiment.

[0052] As shown in FIG. 6 , in this embodiment, the pixel 2 has a configuration similar to that of the pixel 2 according to the first embodiment. However, unlike the first embodiment, in this embodiment, the lower electrode 11 further includes a plurality of columnar electrodes 112 extending to the photoelectric conversion layer 13 in the thickness direction of the photoelectric conversion layer 13. As shown in FIG. 7 , the plurality of columnar electrodes 112 have a rectangular shape (an example of a case where the columnar electrodes 112 have a polygonal cross section) in a plan view of the semiconductor substrate 70, and are provided in a central region of the lower electrode 11. Furthermore, if the photoelectric conversion layer 13 contains quantum dots, the distance d2 between adjacent columnar electrodes 112 is preferably equal to or greater than the particle diameter of the quantum dots, and more specifically, is, for example, equal to or greater than 10 nm.

[0053] In this embodiment, the columnar electrode 112 is formed from a reflective material that reflects incident light. As described above, the reflective material contains at least one metal species selected from the group consisting of copper, aluminum, and gold. Furthermore, since the columnar electrode 112 is integrated with the protruding electrode 111 and the lower electrode 11, it is easy to manufacture the lower electrode 11, the protruding electrode 111, and the columnar electrode 112. Therefore, it is preferable that the columnar electrode 112 is formed from the same material as the lower electrode 11 and the protruding electrode 111. Furthermore, the reflective material that forms the columnar electrode 112 is preferably, for example, 10 －８ It is preferable that the material has a resistance value of Ω / cm or less.

[0054] 6, the outermost surfaces of the protruding electrodes 111, the lower electrodes 11, and the columnar electrodes 112 are preferably covered with the charge transport layer 14. In this embodiment, covering the outermost surfaces of the protruding electrodes 111, the lower electrodes 11, and the columnar electrodes 112 with the charge transport layer 14 promotes the supply of charges generated in the photoelectric conversion layer 13 to the lower electrodes 11. Furthermore, in this embodiment, providing the columnar electrodes 112 increases the contact area between the photoelectric conversion layer 13 and the charge transport layer 14, thereby improving the adhesion between the photoelectric conversion layer 13 and the charge transport layer 14.

[0055] In this embodiment, the lower electrode 11 extends in the thickness direction of the photoelectric conversion layer 13 and has a plurality of columnar electrodes 112 made of a reflective material. For example, as shown in FIG. 8 , in this embodiment, the columnar electrodes 112 can reflect light L1 incident at an oblique angle to the upper surface of the lower electrode 11 to the photoelectric conversion layer 13 on the lower electrode 11. Therefore, according to this embodiment, it is possible to suppress leakage of light to the outside of the pixel 2 and efficiently collect light in the photoelectric conversion layer 13. As a result, according to this embodiment, it is possible to improve the photoelectric conversion efficiency of the photodetector 1.

[0056] Furthermore, according to this embodiment, by providing a plurality of columnar electrodes 112 made of a reflective material, light L2 incident at an oblique angle to the upper surface of the lower electrode 11 is repeatedly reflected by the columnar electrodes 112, and the light travels between the columnar electrodes 112, as shown in Fig. 9. Therefore, in this embodiment, the optical path length in the photoelectric conversion layer 13 is lengthened, and the photoelectric conversion efficiency is further improved.

[0057] Furthermore, in this embodiment, the plurality of columnar electrodes 112 provided in the lower electrode 11 extend into the photoelectric conversion layer 13. Therefore, according to this embodiment, as shown in Fig. 10, the charge C1 generated inside the photoelectric conversion layer 13 can be efficiently guided to the lower electrode 11 by the columnar electrodes 112, thereby reducing the charge C1 that cannot reach the lower electrode 11 and is deactivated. As a result, according to this embodiment, the photoelectric conversion efficiency of the photodetector 1 can be improved.

[0058] Furthermore, in this embodiment, by forming the columnar electrode 112 from the same material as the lower electrode 11, the columnar electrode 112 has a higher carrier mobility than the charge transport layer 14, and can therefore efficiently guide charges to the lower electrode 11. Therefore, according to this embodiment, the photoelectric conversion efficiency of the photodetector 1 can be improved.

[0059] 11 shows a cross section of adjacently arranged pixels 2 according to the second embodiment. In this embodiment, too, a protruding electrode 111 made of a reflective material is provided along the inner periphery of the lower electrode 11. The protruding electrode 111B reflects light L4 incident from the adjacent pixel 2A toward the pixel 2A, preventing the light L4 from entering the pixel 2B. Therefore, according to this embodiment, the leakage light L4 incident from the adjacent pixel 2A does not generate charge in the pixel 2B, thereby suppressing the generation of erroneous charge in the pixel 2B, which can result in, for example, color mixing.

[0060] That is, according to this embodiment, the characteristics of the photodetector 1 can be further improved.

[0061] The configuration of this embodiment is not limited to the configuration examples shown in FIGS.

[0062] 12 and 13 are plan views illustrating the configuration of a columnar electrode 112 according to a modification of the second embodiment. As shown in FIGS. 12 and 13, the plurality of columnar electrodes 112 may have, for example, a substantially circular shape ( FIG. 12 ) or a substantially polygonal shape ( FIG. 13 ) in a plan view of the semiconductor substrate 70. In this modification, changing the cross-sectional shape of the columnar electrodes 112 in this manner may provide efficient reflection and facilitate the manufacture of the photodetector 1. In addition, in this modification, the cross-sectional shape of the columnar electrodes 112 may be changed depending on the position of the pixel 2 within the pixel region 3, i.e., depending on the angle and direction of incidence of light with respect to the pixel 2. Furthermore, in this modification, the plurality of columnar electrodes 112 are not limited to being regularly arranged on the lower electrode 11, but may be randomly arranged.

[0063] (2-3. Third Embodiment) Next, a third embodiment will be described with reference to Fig. 14 and Fig. 15. Fig. 14 is a cross-sectional schematic diagram showing the configuration of two adjacent pixels 2 of a photodetector 1 according to the third embodiment, and Fig. 15 is a plan view showing the configuration of the lower electrode 11 shown in Fig. 14.

[0064] In this embodiment, the pixel 2 has the same configuration as the pixel 2 according to the second embodiment. However, unlike the second embodiment, in this embodiment, the protruding electrode 111 is covered with an insulating layer 15 as shown in Figures 14 and 15 . Note that in this embodiment, it is sufficient that at least the protruding electrode 111 on the side of the adjacent pixel 2 is covered with the insulating layer 15. The insulating layer 15 can be formed from, for example, silicon oxide, silicon nitride, aluminum oxide, or the like.

[0065] As described above, in this embodiment, the side of the protruding electrode 111 facing the adjacent pixel 2 is covered with the insulating layer 15. By doing so, for example, even if leakage light L6 from the adjacent pixel 2A is absorbed in the region of the photoelectric conversion layer 13 adjacent to pixel 2B and generates an electric charge, the presence of the insulating layer 15B prevents the electric charge from being extracted by the protruding electrode 111B. As a result, according to this embodiment, the electric charge generated by leakage light L6 incident from the adjacent pixel 2A side is not extracted by the protruding electrode 111B of pixel 2B, thereby preventing color mixing, or the pixel 2B from mistakenly capturing light that should be captured by the adjacent pixel 2A. In other words, according to this embodiment, the characteristics of the photodetector 1 can be further improved.

[0066] The configuration of this embodiment is not limited to the configuration examples shown in FIGS.

[0067] (2-4. Fourth Embodiment) Next, a fourth embodiment will be described with reference to Fig. 16 and Fig. 17. Fig. 16 is a cross-sectional schematic diagram showing the configuration of each unit pixel 2 of a photodetector 1 according to the fourth embodiment. Fig. 17 is a plan view showing the configuration of each unit pixel 2 of the photodetector 1 shown in Fig. 16.

[0068] In this embodiment, the pixel 2 has the same configuration as the pixel 2 according to the second embodiment. However, unlike the second embodiment, in this embodiment, an upper reflective layer 16 and a lower reflective layer 17 are provided, as shown in FIGS. 16 and 17 .

[0069] 16 and 17 , in this embodiment, the photoelectric conversion layer 13 extends across a plurality of pixels 2, and an upper reflective layer 16 is provided on the light incident surface 13A side of the photoelectric conversion layer 13 located between adjacent pixels 2. The upper reflective layer 16 preferably overlaps at least a portion of the upper surface of the protruding electrode 111 in a plan view of the semiconductor substrate 70. Furthermore, in this embodiment, as shown in FIG. 16 , a lower reflective layer 17 is provided on a surface 13B opposite to the light incident surface 13A of the photoelectric conversion layer 13 located between adjacent pixels 2.

[0070] In this embodiment, the upper reflective layer 16 and the lower reflective layer 17 are formed from a reflective material, and may be, for example, a multilayer film of aluminum oxide and silicon oxide, or may be formed from a low refractive index resin.

[0071] 16 , in this embodiment, the lower electrode 11 is made of a reflective material, and therefore light L73 that directly reaches the lower electrode 11 is reflected by the lower electrode 11. However, in this embodiment, the light reflected by the lower electrode 11 is reflected by the upper reflective layer 16, and is therefore confined within the photoelectric conversion layer 13, preventing it from leaking upward from the pixel 2. Therefore, according to this embodiment, light is confined within the photoelectric conversion layer 13, and therefore the photoelectric conversion efficiency of the photodetector 1 can be improved.

[0072] Furthermore, in this embodiment, even if light reflected by the upper reflective layer 16 travels to the photoelectric conversion layer 13 between adjacent pixels 2 (shown as arrow L82 in FIG. 16 ), it is reflected by the lower reflective layer 17, and the light can be confined within the photoelectric conversion layer 13. Therefore, according to this embodiment, light is confined within the photoelectric conversion layer 13, and therefore the photoelectric conversion efficiency of the photodetector 1 can be improved. That is, according to this embodiment, the characteristics of the photodetector 1 can be further improved.

[0073] The configuration of this embodiment is not limited to the configuration examples shown in FIGS. 16 and 17, but it is sufficient that at least the upper reflective layer 16 is provided.

[0074] (2-5. Fifth Embodiment) Next, a fifth embodiment will be described with reference to Fig. 18 and Fig. 19. Fig. 18 is a cross-sectional view showing the configuration of two adjacent pixels 2 of a photodetector 1 according to the fourth embodiment, and Fig. 19 is a cross-sectional view showing the configuration of two adjacent pixels 2 of a photodetector 1 according to the fifth embodiment.

[0075] As shown in Fig. 18 , in the fourth embodiment described above, light L81 incident on pixel 2A is reflected by the protruding electrode 111A, reaches the upper reflective layer 16, and is reflected by the upper reflective layer 16. Furthermore, light L81 reflected by the upper reflective layer 16 may reach the protruding electrode 111B of the adjacent pixel 2B, be reflected, and leak out above the pixel 2B. Alternatively, in the example shown in Fig. 18 , light L81 may reach the protruding electrode 111B of the adjacent pixel 2B and generate charges in the photoelectric conversion layer 13 of the pixel 2B due to the reflected light. In such a case, in the fourth embodiment, there is a possibility that light that should be captured by the adjacent pixel 2A may be mistakenly captured by the pixel 2B, such as color mixing.

[0076] Therefore, in the fifth embodiment, as shown in Fig. 19, the protruding electrodes 111 are extended so as to contact the upper reflective layer 16. In this embodiment, the extending protruding electrodes 111 can block light leakage to adjacent pixels 2. Therefore, this embodiment can avoid color mixing, for example, where light that should be captured by adjacent pixel 2A is mistakenly captured by pixel 2B. In other words, this embodiment can further improve the characteristics of the photodetector 1.

[0077] The configuration of this embodiment is not limited to the example configuration shown in Fig. 19. For example, in the example of Fig. 19, the columnar electrode 112 also extends so as to contact the upper electrode 12. However, this embodiment is not limited to this configuration, and the columnar electrode 112 does not have to contact the upper electrode 12.

[0078] 20 is a cross-sectional view showing a configuration of two adjacent pixels 2 of a photodetector 1 according to a modification of the fifth embodiment. As shown in FIG. 20, this modification does not include the upper reflective layer 16 and the lower reflective layer 17 of the fifth embodiment.

[0079] In this modification as well, the protruding electrodes 111 can block light leakage to adjacent pixels 2. Therefore, this modification can avoid color mixing, for example, where light that should be captured by adjacent pixel 2A is mistakenly captured by pixel 2B.

[0080] In this modified example, the columnar electrode 112 is not limited to being extended so as to be in contact with the upper electrode 12 , and for example, the columnar electrode 112 does not have to be in contact with the upper electrode 12 .

[0081] (2-6. Sixth Embodiment) Next, a sixth embodiment will be described with reference to Fig. 21. Fig. 21 is a cross-sectional view showing the configuration of two adjacent pixels 2 of a photodetector 1 according to the sixth embodiment.

[0082] If an oxide film is used for the charge transport layer 14, the lower electrode 11, the protruding electrode 111, and the columnar electrode 112, which are in contact with the charge transport layer 14, may be oxidized, resulting in increased resistance. Therefore, the lower electrode 11, the protruding electrode 111, and the columnar electrode 112 may be formed from a material with high oxidation resistance, such as ITO or IZO. However, these materials are transparent conductive materials and therefore cannot reflect light. Therefore, in such a case, light incident on the pixel 2 is not confined within the pixel 2 but escapes below the lower electrode 11, thereby reducing the photoelectric conversion efficiency of the photodetector 1.

[0083] Therefore, in this embodiment, as shown in Fig. 21 , a reflective layer 19 is provided to cover the lower electrode 11 and the protruding electrode 111 made of a transparent conductive material. According to this embodiment, similar to the embodiments described so far, light is reflected by the reflective layer 19 (arrow L9 in Fig. 21 ), thereby suppressing leakage of light to the outside of the pixel 2 and enabling efficient collection of light on the photoelectric conversion layer 13. As a result, according to this embodiment, the photoelectric conversion efficiency of the photodetector 1 can be improved.

[0084] 21 , in this embodiment, a reflective layer 19 is provided so as to cover the outermost surfaces of the lower electrode 11 and the protruding electrode 111. In this embodiment, it is sufficient that at least the region of the upper surface (outermost surface) of the lower electrode 11 that is close to the protruding electrode 111 is covered with the reflective layer (second reflective layer) 19. In this embodiment, the reflective layer 19 does not need to be provided on the columnar electrode 112 that mainly contributes to extracting the charges generated in the photoelectric conversion layer 13.

[0085] In this embodiment, the reflective layer 19 may be, for example, a multilayer film of aluminum oxide and silicon oxide, or may be formed from a low refractive index resin. Alternatively, in this embodiment, the reflective layer 19 is formed from a reflective material that reflects incident light. As described above, the reflective material includes, for example, at least one metal species selected from the group consisting of copper, aluminum, and gold. Furthermore, the reflective material forming the reflective layer 19 is preferably, for example, 10% or more, in order to reduce the resistance of the lower electrode 11. －８ It is preferable that the material has a resistance value of Ω / cm or less.

[0086] As described above, in this embodiment, the reflective layer 19 is provided so as to cover the outermost surfaces of the lower electrode 11 and the protruding electrode 111, thereby reflecting incident light to the photoelectric conversion layer 13 on the lower electrode 11 (arrow L9 in FIG. 21 ). Therefore, this embodiment can suppress light leakage to the outside of the pixel 2 and efficiently focus light on the photoelectric conversion layer 13. As a result, this embodiment can improve the photoelectric conversion efficiency of the photodetector 1. Furthermore, this embodiment causes light to travel through the photoelectric conversion layer 13 while being repeatedly reflected by the reflective layer 19 covering the lower electrode 11 and the protruding electrode 111. Therefore, in this embodiment, the optical path length within the photoelectric conversion layer 13 is lengthened, further improving the photoelectric conversion efficiency. That is, this embodiment can further improve the characteristics of the photodetector 1.

[0087] The configuration of this embodiment is not limited to the example configuration shown in Fig. 21. In the example shown in Fig. 21, the reflective layer 19 is provided so as to cover only the outermost surfaces of the lower electrode 11 and the protruding electrode 111, but this is not limiting. In this embodiment, for example, only the outermost surface of the protruding electrode 111 may be covered with the reflective layer 19.

[0088] 22 is a schematic cross-sectional view and a plan view showing the configuration of two pixels 2 according to a modification of the sixth embodiment. As shown in Fig. 22, in this modification, only the outermost surface of the protruding electrode 111 is covered with the reflective layer 19. In this modification, it is sufficient that at least the outermost surface of the protruding electrode 111 on the central side of the lower electrode 11 is covered with the reflective layer (first reflective layer) 19.

[0089] In this manner, in this modification, by providing the reflective layer 19 so as to cover the outermost surface of the protruding electrode 111, incident light can be reflected to the photoelectric conversion layer 13 on the lower electrode 11 (arrow L9 in FIG. 22 ). Therefore, according to this embodiment, it is possible to suppress leakage of light to the outside of the pixel 2 and to efficiently collect light on the photoelectric conversion layer 13. As a result, according to this embodiment, it is possible to improve the photoelectric conversion efficiency of the photodetector 1.

[0090] 22, in this embodiment, by covering the protruding electrodes 111A, 111B between adjacent pixels 2A, 2B with the reflective layer 19, the opposing length of the electrodes between the adjacent pixels 2A, 2B increases, which increases the likelihood of leakage between the adjacent pixels 2A, 2B. In such a case, the distance between the adjacent pixels 2A, 2B may be increased, the reflective layer 19 may not be provided on the outermost surface of the protruding electrode 111 on the side of the adjacent pixel 2, or an insulating layer (not shown) may be provided between the protruding electrodes 111A, 111B between the adjacent pixels 2A, 2B.

[0091] (2-7. Seventh Embodiment) Next, a seventh embodiment will be described with reference to Fig. 23. Fig. 23 is a schematic cross-sectional view and a plan view illustrating the configuration of two adjacent pixels 2 of a photodetector 1 according to the seventh embodiment.

[0092] In the sixth embodiment described above, as explained earlier, the lower electrode 11, the protruding electrode 111, and the columnar electrode 112 are formed of a transparent conductive material, but in this embodiment, the lower electrode 11, the protruding electrode 111, and the columnar electrode 112 are also formed of a transparent conductive material.

[0093] In this embodiment, as shown in the center of Figure 23, the protruding electrodes 111A and 111B between adjacent pixels 2A and 2B increase the opposing length of the electrodes between the adjacent pixels 2A and 2B, increasing the likelihood of leakage between the adjacent pixels 2A and 2B. Furthermore, in this embodiment, for example, leakage light from the adjacent pixel 2A may be absorbed in a region of the photoelectric conversion layer 13 adjacent to the pixel 2B, generating charges, which may then be extracted by the protruding electrode 111B of the pixel 2B. In such a case, in this embodiment, there is a possibility that light that should be captured by the adjacent pixel 2A may be mistakenly captured by the pixel 2B, resulting in color mixing.

[0094] 23, an insulating layer 20 is provided to cover the outermost surface of the protruding electrode 111, as in the third embodiment described above. In this embodiment, it is sufficient that at least the protruding electrode 111 on the side facing the adjacent pixel 2 is covered with the insulating layer 20. The insulating layer 20 can be made of, for example, silicon oxide, silicon nitride, aluminum oxide, or the like.

[0095] As described above, in this embodiment, the protruding electrode 111 is covered with the insulating layer 20. According to this embodiment, by providing such an insulating layer 20, it is possible to suppress leakage between adjacent pixels 2A and 2B even if the opposing length of the electrodes between adjacent pixels 2A and 2B is increased. In addition, according to this embodiment, the distance between the pixels 2A and 2B can be shortened. Furthermore, in this embodiment, even if, for example, leakage light from the adjacent pixel 2A is absorbed in a region of the photoelectric conversion layer 13 adjacent to pixel 2B and generates charge, the presence of the insulating layer 20B prevents the charge from being extracted by the protruding electrode 111B. As a result, according to this embodiment, it is possible to suppress color mixing, which occurs when pixel 2B mistakenly captures light that should be captured by the adjacent pixel 2A. In other words, according to this embodiment, the characteristics of the photodetector 1 can be further improved.

[0096] The configuration of this embodiment is not limited to the configuration example shown in Fig. 23. For example, this embodiment may be combined with the fourth, fifth, or sixth embodiment described above.

[0097] As described above, according to the embodiments and modifications of the present disclosure, the characteristics of the photodetector 1 can be further improved.

[0098] (3. Flow of Manufacturing Method) Next, with reference to FIG. 24, an example of a method for manufacturing the pixel 2 according to the first embodiment will be described.

[0099] First, as shown in the top left corner of Fig. 24, the lower electrode 11 is formed on the wiring layer 73 by sputtering or the like. Next, as shown in the second from the top left corner of Fig. 24, a metal film (e.g., Cu, Al, etc.) that will become the protruding electrode 111 is formed. Then, as shown in the third from the top left corner of Fig. 24, a photoresist 200 having a pattern of the protruding electrode 111 is formed on the metal film that will become the protruding electrode 111.

[0100] 24, the metal film that will become the protruding electrodes 111 is dry-etched or the like according to the pattern of the photoresist 200 to form the protruding electrodes 111. Then, as shown in the fourth diagram from the left in the top row of Fig. 24, the charge transport layer 14 is formed by using an ALD (Atomic Layer Deposition) method or the like so as to cover the lower electrode 11 and the protruding electrodes 111.

[0101] Next, as shown in the lower left corner of Fig. 24 , the photoelectric conversion layer 13 is formed on the charge transport layer 14 by coating. Furthermore, as shown in the second from the left end of the lower row of Fig. 24 , the upper electrode 12 is formed on the photoelectric conversion layer 13. Then, as shown in the third from the left end of the lower row of Fig. 24 , a planarization film 82 is formed on the upper electrode 12 by coating. Furthermore, as shown in the lower right corner of Fig. 24 , an on-chip lens 90 is formed on the planarization film 82.

[0102] It should be noted that the method for manufacturing the pixel 2 according to this embodiment is not limited to the example shown in FIG.

[0103] Furthermore, in this embodiment, it is possible to manufacture the semiconductor device by using the method, apparatus, and conditions that are used in the manufacture of a general semiconductor device, i.e., in this embodiment, it is possible to use the existing semiconductor device manufacturing process.

[0104] Examples of the above-mentioned method include a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, and an ALD method. Examples of the PVD method include a vacuum deposition method, an electron beam (EB) deposition method, various sputtering methods (magnetron sputtering method, RF (radio frequency)-DC (direct current) combined bias sputtering method, ECR (electron cyclotron resonance) sputtering method, facing target sputtering method, and high frequency sputtering method), an ion plating method, a laser ablation method, a molecular beam epitaxy method (MBE (molecular beam epitaxy) method), and a laser transfer method. Examples of CVD methods include plasma CVD, thermal CVD, metal organic (MO) CVD, and photo-CVD. Other methods include electroplating, electroless plating, 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. Examples of patterning methods include chemical etching such as shadow masking, laser transfer, and photolithography, and physical etching using ultraviolet light or lasers. Additionally, examples of planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0105] (4. Application Examples to Electronic Devices) The photodetector 1 as described above can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, or other devices with imaging functions.

[0106] 25 is a block diagram showing an example of the configuration of an electronic device 1000. The electronic device 1000 includes an optical system 1001, a photodetector 1002, and a DSP (Digital Signal Processor) 1003, and is configured by connecting the DSP 1003, a display device 1004, an operation system 1005, a memory 1007, a recording device 1008, and a power supply system 1009 via a bus 1006, and is capable of capturing still images and moving images.

[0107] The optical system 1001 is configured to have one or more lenses, and guides image light (incident light) from an object to the photodetector 1002 , forming an image on the light receiving surface (sensor portion) of the photodetector 1002 .

[0108] The photodetector 1002 may be the photodetector 1 described above. Electrons are accumulated in the photodetector 1002 for a certain period of time in accordance with an image formed on the light-receiving surface via the optical system 1001. A signal corresponding to the electrons accumulated in the photodetector 1002 is then supplied to the DSP 1003.

[0109] The DSP 1003 performs various signal processing on the signal from the photodetector 1002 to acquire an image, and temporarily stores the image data in the memory 1007. The image data stored in the memory 1007 is recorded in the recording device 1008 or supplied to the display device 1004 to display the image. In addition, the operation system 1005 accepts various operations by the user and supplies operation signals to each block of the electronic device 1000, and the power supply system 1009 supplies the power necessary to drive each block of the electronic device 1000.

[0110] (5. Application Example to Light Detection System) FIG. 26 is a schematic diagram showing an example of the overall configuration of a light detection system 2000. FIG. 27 is a diagram showing an example of the circuit configuration of the light detection system 2000 shown in FIG. 26. As shown in FIG. 27, the light detection system 2000 includes a light emitting device 2001 as a light source unit that emits infrared light, and a light detecting device 2002 as a light receiving unit having a photoelectric conversion element. The light detecting device 1 described above can be used as the light detecting device 2002. The light detecting 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.

[0111] As shown in FIG. 26 , the photodetector 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by a subject (object to be measured) 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 region 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 photodetector system 2000 can be obtained from light L2. The photodetector system 2000 can be mounted, for example, on 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, by a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting the light L2 emitted from the light emitting device 2001 by the photodetector 2002 can be, for example, an iTOF system, but is not limited to this. In the iTOF system, the photoelectric conversion unit detects, for example, the time of flight of light (T ＯThe distance to the subject 2100 can be measured by time-of-flight (F). The light detection device 2002 can detect the light L2 emitted from the light emitting device 2001 using, for example, a structured light method or a stereo vision method. For example, with the structured light method, a predetermined pattern of light is projected onto the subject 2100, and the distance between the light detection system 2000 and the subject 2100 can be measured by analyzing the distortion of the pattern. Furthermore, with 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. The light emitting device 2001 and the light detection device 2002 can be synchronously controlled by a system control unit 2003.

[0112] (6. Application Examples to Mobile Bodies) 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.

[0113] FIG. 28 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 according to the present disclosure can be applied.

[0114] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 28, 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0121] 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.

[0122] 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.

[0123] 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 the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 36, 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.

[0124] FIG. 29 is a diagram showing an example of the installation position of the imaging unit 12031.

[0125] In FIG. 29, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0126] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0127] 29 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.

[0128] 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.

[0129] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation.

[0130] 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.

[0131] 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.

[0132] An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 of the above-described configuration. Specifically, the light detection device 1 of FIG. 1 can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to obtain a captured image that is easier to see, thereby reducing driver fatigue.

[0133] (7. Application Example to Endoscopic Surgery System) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0134] FIG. 30 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.

[0135] 30 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.

[0136] 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.

[0137] 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.

[0138] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0139] 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.

[0140] 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.

[0141] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies irradiation light to the endoscope 11100 when photographing the surgical area, etc.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissue (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0147] FIG. 31 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0148] 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.

[0149] 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.

[0150] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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 .

[0157] 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.

[0158] 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.

[0159] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] The foregoing has described 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 imaging unit 11402 of the camera head 11102 in the configuration described above. Specifically, the light detection device 1 according to the present disclosure can be applied to the imaging unit 11402. By applying the technology according to the present disclosure to the imaging unit 11402, a clearer image of the surgical site can be obtained, allowing the surgeon to reliably confirm the surgical site.

[0165] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0166] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure can conceive of various modified or altered examples within the scope of the technical idea described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0167] Note that the following configurations also fall within the technical scope of the present disclosure. (1) A photodetector comprising pixels arranged on a substrate, the pixels including: a photoelectric conversion layer that generates charges in response to incident light; an upper electrode provided on the light incident surface side of the photoelectric conversion layer; and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, the lower electrode including a protruding electrode extending to the photoelectric conversion layer in a thickness direction of the photoelectric conversion layer, the protruding electrode being provided along the inner periphery of the lower electrode in a plan view of the substrate, and including a reflective material that reflects the incident light. (2) The photodetector according to (1), wherein the protruding electrode has a frame-like shape that surrounds a central portion of an upper surface of the lower electrode. (3) The photodetector according to (1) or (2), wherein the protruding electrode is formed from the reflective material. (4) The photodetector according to (3), wherein the lower electrode is formed from the reflective material. (5) The photodetector according to (1) or (2), wherein at least a central portion of the protruding electrode facing the lower electrode is covered with a first reflective layer made of the reflective material. (6) The photodetector according to (5), wherein at least a portion of the lower electrode is covered with a second reflective layer made of the reflective material. (7) The photodetector according to (5) or (6), wherein the lower electrode and the protruding electrode are formed of a transparent conductive material. (8) The photodetector according to any one of (1) to (4), wherein the lower electrode has a plurality of columnar electrodes extending to the photoelectric conversion layer in a thickness direction of the photoelectric conversion layer, and the plurality of columnar electrodes are provided in a central region of the lower electrode in a planar view of the substrate. (9) The photodetector according to (8), wherein the plurality of columnar electrodes have a substantially circular or substantially polygonal shape in a planar view of the substrate. (10) The photodetector according to (8) or (9), wherein the columnar electrodes are formed of the reflective material. －８The photodetector according to any one of (1) to (10) above, wherein the reflective material is a material having a resistance value of Ω / cm or less. (12) The photodetector according to any one of (1) to (10) above, wherein the reflective material is a metal material containing at least one metal species selected from the group consisting of copper, aluminum, and gold, an oxide film material containing aluminum or silicon, or a low refractive index resin. (13) The photodetector according to any one of (8) to (10) above, wherein the outermost surfaces of the protruding electrode, the lower electrode, and the columnar electrode are covered with a charge transport layer. (14) The photodetector according to any one of (1) to (13) above, comprising a plurality of the pixels arranged in a matrix on the substrate. (15) The photodetector according to (14) above, wherein at least the side of the protruding electrode facing an adjacent pixel is covered with an insulating layer. (16) A photodetector comprising a plurality of pixels arranged in a matrix on a substrate, wherein the pixels have: a photoelectric conversion layer that generates charges in response to incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, wherein the lower electrode has a protruding electrode extending to the photoelectric conversion layer in a thickness direction of the photoelectric conversion layer, the protruding electrode being provided along an inner periphery of the lower electrode in a plan view of the substrate, at least the side of the protruding electrode facing an adjacent pixel being covered with an insulating layer, and the lower electrode and the protruding electrode being formed of a transparent conductive material. (17) The photodetector according to any one of (14) to (16) above, wherein the photoelectric conversion layer extends across the plurality of pixels, and an upper reflective layer is provided on the light incident surface side of the photoelectric conversion layer located between the adjacent pixels. (18) The photodetector according to (17) above, wherein the upper reflective layer overlaps at least a part of an upper surface of the protruding electrode when the substrate is viewed in a plan view. (19) The photodetector according to (17) or (18) above, wherein a lower reflective layer is provided on a surface of the photoelectric conversion layer located between adjacent pixels on the opposite side to the light incident surface. (20) The photodetector according to any one of (17) to (19) above, wherein the protruding electrode extends so as to be in contact with the upper reflective layer.(21) The photodetector according to (19) or (20) above, wherein the upper reflective layer and the lower reflective layer are made of an oxide film material containing aluminum or silicon, or a low refractive index resin. (22) The photodetector according to any one of (14) to (21) above, wherein the lower electrode is provided for each of the pixels. (23) The photodetector according to any one of (14) to (22) above, further comprising a plurality of on-chip lenses provided above the upper electrode for each of the pixels. (24) The photodetector according to any one of (1) to (16) above, wherein the photoelectric conversion layer includes quantum dots, an organic material, or an inorganic material. (25) An electronic device equipped with a photodetector, wherein the photodetector includes pixels arranged on a substrate, each pixel having a photoelectric conversion layer that generates electric charges in response to incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, wherein the lower electrode has a protruding electrode that extends to the photoelectric conversion layer in the thickness direction of the photoelectric conversion layer, and the protruding electrode is provided along the inner periphery of the lower electrode in a planar view of the substrate, and includes a reflective material that reflects the incident light. (26) An electronic device equipped with a photodetector, wherein the photodetector comprises a plurality of pixels arranged in a matrix on a substrate, each of the pixels having: a photoelectric conversion layer that generates electric charges in response to incident light; an upper electrode provided on the light incident surface side of the photoelectric conversion layer; and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, wherein the lower electrode has a protruding electrode that extends to the photoelectric conversion layer in a thickness direction of the photoelectric conversion layer, and the protruding electrode is provided along an inner periphery of the lower electrode in a planar view of the substrate, and at least the side of the protruding electrode facing an adjacent pixel is covered with an insulating layer, and the lower electrode and the protruding electrode are formed of a transparent conductive material.

[0168] REFERENCE SIGNS LIST 1 Photodetector device 2, 2A, 2B Pixel 3 Pixel region 4 Vertical drive circuit 5 Column signal processing circuit 6 Horizontal drive circuit 7 Output circuit 8 Control circuit 9 Vertical signal line 10 Horizontal signal line 11, 11A, 11B Lower electrode 12 Upper electrode 13 Photoelectric conversion layer 13A Light incident surface 13B Surface 14 Charge transport layer 15, 15A, 15B, 20, 20A, 20B Insulating layer 16 Upper reflective layer 17 Lower reflective layer 19 Reflective layer 51B, 52C, 53C Source / drain region 51C Charge storage section 52 Gate section 61, 64 Via 62, 63 Wiring 70 Semiconductor substrate 70A First surface 71 Element isolation region 72 Oxide film 73 Wiring layer 80 Input / output terminal 82 Planarization film 90, 90A, 90B On-chip lens 111, 111A, 111B Projecting electrode 112, 112A, 112B Columnar electrode 200 Photoresist

Claims

1. A photodetector comprising pixels arranged on a substrate, each pixel having a photoelectric conversion layer that generates electric charges in response to incident light, an upper electrode provided on the light incident surface side of the photoelectric conversion layer, and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, wherein the lower electrode has a protruding electrode that extends to the photoelectric conversion layer in a thickness direction of the photoelectric conversion layer, the protruding electrode being provided along an inner periphery of the lower electrode in a plan view of the substrate, and including a reflective material that reflects the incident light.

2. The photodetector according to claim 1, wherein the protruding electrode has a frame shape surrounding the center of the upper surface of the lower electrode.

3. The photodetector according to claim 1, wherein the protruding electrodes are formed from the reflective material.

4. The photodetector device according to claim 3, wherein the lower electrode is formed from the reflective material.

5. The photodetector according to claim 1, wherein at least the central portion of the protruding electrode facing the lower electrode is covered with a first reflective layer made of the reflective material.

6. The photodetector according to claim 5, wherein at least a portion of the lower electrode is covered with a second reflective layer made of the reflective material.

7. The photodetector according to claim 5, wherein the lower electrode and the protruding electrode are formed from a transparent conductive material.

8. The photodetector device according to claim 1, wherein the lower electrode has a plurality of columnar electrodes extending to the photoelectric conversion layer in the thickness direction of the photoelectric conversion layer, and the plurality of columnar electrodes are provided in a central region of the lower electrode when viewed in a plane of the substrate.

9. The photodetector according to claim 8, wherein the columnar electrodes are formed from the reflective material.

10. The photodetector according to claim 1, wherein the reflective material is a metal material containing at least one metal species selected from the group consisting of copper, aluminum, and gold, an oxide film material containing aluminum or silicon, or a low refractive index resin.

11. The photodetector according to claim 8, wherein the outermost surfaces of the protruding electrode, the lower electrode and the columnar electrode are covered with a charge transport layer.

12. The photodetector device according to claim 1, comprising a plurality of the pixels arranged in a matrix on the substrate.

13. The photodetector according to claim 12, wherein at least the protruding electrode on the side facing an adjacent pixel is covered with an insulating layer.

14. A photodetector comprising a plurality of pixels arranged in a matrix on a substrate, each pixel having: a photoelectric conversion layer that generates electric charges in response to incident light; an upper electrode provided on the light incident surface side of the photoelectric conversion layer; and a lower electrode provided on the surface of the photoelectric conversion layer opposite the light incident surface, wherein the lower electrode has a protruding electrode extending to the photoelectric conversion layer in the thickness direction of the photoelectric conversion layer, the protruding electrode being provided along the inner periphery of the lower electrode in a plan view of the substrate, at least the side of the protruding electrode facing an adjacent pixel being covered with an insulating layer, and the lower electrode and the protruding electrode being formed from a transparent conductive material.

15. The photodetector according to claim 12, wherein the photoelectric conversion layer extends across the plurality of pixels, and an upper reflective layer is provided on the light incident surface side of the photoelectric conversion layer located between adjacent pixels.

16. The photodetector according to claim 15, wherein a lower reflective layer is provided on the surface of the photoelectric conversion layer located between adjacent pixels, opposite to the light incident surface.

17. The photodetector according to claim 15, wherein the protruding electrode extends so as to contact the upper reflective layer.

18. The photodetector device according to claim 12, wherein the lower electrode is provided for each pixel.

19. The photodetector according to claim 12, further comprising a plurality of on-chip lenses provided above the upper electrode for each of the pixels.

20. The photodetector device according to claim 1, wherein the photoelectric conversion layer includes quantum dots, an organic material, or an inorganic material.

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