Photodetector

Abstract

The light detection device includes: a first photoelectric conversion element disposed on a light incident side of a first substrate and converting incident light into an electric charge; and a second photoelectric conversion element disposed to overlap the first photoelectric conversion element within the first substrate, and including a multiplication region for multiplying carriers generated by light.

Description

Technical Field

[0001] The present disclosure relates to a light detector. Background Art

[0002] Patent Document 1 discloses a solid-state imaging device having a stacked structure including a first photoelectric conversion region that photoelectrically converts received visible light and a second photoelectric conversion region that photoelectrically converts received infrared light. The solid-state imaging device configured in this manner can generate infrared light images with high resolution while maintaining high image quality of visible light images. List of citations Patent Literature

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-208496 Summary of the Invention

[0004] Solid-state imaging devices can be used to measure distance using infrared light. Conventional distance measurement methods include structured light (Structured Light), indirect time-of-flight (i-ToF), and direct time-of-flight (d-ToF). Meanwhile, although the second photoelectric conversion region that photoelectrically converts infrared light is formed using a photodiode and is suitable for short-distance measurement, the second photoelectric conversion region is not suitable for medium- and long-distance measurement. Therefore, there is a need to develop a photodetector that can increase the distance measurement range.

[0005] According to a first embodiment of the present disclosure, a photodetector includes: a first photoelectric conversion element, which is arranged on a light incident side of a first substrate and converts incident light into electric charges; and a second photoelectric conversion element, which is arranged to overlap with the first photoelectric conversion element in the first substrate and includes a multiplication region that multiplies carriers generated by photons.

[0006] The light detector according to the second embodiment of the present disclosure corresponds to the light detector according to the first embodiment, and also includes a light-shielding body arranged along the periphery of the second photoelectric conversion element when viewed from the light incident side, and the light-shielding body passes through at least the first substrate in the thickness direction and blocks the carriers generated from the second photoelectric conversion element.

[0007] According to the third embodiment of the present disclosure, the light detector includes: a first base, which includes a first semiconductor substrate and a first insulating layer stacked on the first semiconductor substrate; a second photoelectric conversion element, which is arranged in the first base and includes a multiplication region for multiplying carriers generated by photons; and a light-shielding body, which is arranged along the periphery of the second photoelectric conversion element when observed from the light incident side, and the light-shielding body passes through at least the first semiconductor substrate in the thickness direction and blocks the carriers generated by the second photoelectric conversion element. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [ Figure 1 ] Figure 1 is a vertical cross-sectional view of a main portion of a photodetector according to a first embodiment of the present disclosure. [ Figure 2 ] Figure 2 yes Figure 1 The main part of the light detector is shown in the plan view (along the Figure 1 (The plane structure diagram is taken along the AA cutting line shown). [ Figure 3 ] Figure 3 yes Figure 1 The main part of the light detector is shown in the plan view (along the Figure 1 (The plane structure diagram is taken along the BB cutting line shown). [ Figure 4 ] Figure 4 yes Figure 1 The main part of the light detector is shown in the plan view (along the Figure 1 (Schematic diagram of the plane structure taken along the CC cutting line shown). [ Figure 5 ] Figure 5 It is magnified Figure 1 An enlarged vertical cross-sectional view of the main part of the photodetector is shown. [ Figure 6 ] Figure 6 yes Figure 1 The circuit diagram of the first photoelectric conversion element of the photodetector and its reading circuit is shown. [ Figure 7 ] Figure 7 yes Figure 1 The circuit diagram of the second photoelectric conversion element of the photodetector and its reading circuit is shown. [ Figure 8 ] Figure 8 This is a method for manufacturing a photodetector according to the first embodiment for explaining each step. Figure 5 Corresponding cross-sectional view of the first process. [ Figure 9 ] Figure 9This is a cross-sectional view of the second step. [ Figure 10 ] Figure 10 This is a cross-sectional view of the third step. [ Figure 11 ] Figure 11 This is a cross-sectional view of the fourth step. [ Figure 12 ] Figure 12 This is a cross-sectional view of the fifth step. [ Figure 13 ] Figure 13 This is a cross-sectional view of the sixth step. [ Figure 14 ] Figure 14 This is a cross-sectional view of the seventh step. [ Figure 15 ] Figure 15 This is a cross-sectional view of the eighth step. [ Figure 16 ] Figure 16 is a photodetector according to the second embodiment of the present disclosure and Figure 5 Corresponding enlarged vertical cross-section structural diagram. [ Figure 17 ] Figure 17 is a photodetector according to a third embodiment of the present disclosure and Figure 5 Corresponding enlarged vertical cross-section structural diagram. [ Figure 18 ] Figure 18 is a photodetector according to a fourth embodiment of the present disclosure and Figure 5 Corresponding enlarged vertical cross-section structural diagram. [ Figure 19 ] Figure 19 is a photodetector according to a fifth embodiment of the present disclosure and Figure 17 Corresponding vertical cross-section structure diagram. [ Figure 20 ] Figure 20 yes Figure 19 The photodetector shown is Figure 3 The corresponding plan structure diagram. [ Figure 21 ] Figure 21 is a photodetector according to a sixth embodiment of the present disclosure and Figure 5 Corresponding enlarged vertical cross-section structural diagram. [ Figure 22 ] Figure 22 It is magnified Figure 21 An enlarged vertical cross-sectional view of the main part of the photodetector is shown. [ Figure 23 ] Figure 23 is a photodetector according to a seventh embodiment of the present disclosure and Figure 22Corresponding enlarged vertical cross-section structural diagram. [ Figure 24 ] Figure 24 is a photodetector according to an eighth embodiment of the present disclosure and Figure 4 The corresponding plan structure diagram. [ Figure 25 ] Figure 25 is a block diagram showing an example of a schematic configuration of a vehicle control system. [ Figure 26 ] Figure 26 It is a diagram for assisting in explaining an example of the installation positions of the vehicle exterior information detection unit and the imaging unit. [ Figure 27 ] Figure 27 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. [ Figure 28 ] Figure 28 is a block diagram illustrating an example of a functional configuration of a camera head and a camera control unit (CCU). DETAILED DESCRIPTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the description will be given in the following order. 1. First Implementation Plan The first embodiment is the first example of applying this technology to a photodetector. This embodiment describes the pixel structure, circuit structure, and photodetector manufacturing method. In particular, this embodiment describes the photoelectric conversion element structure, shield structure, and manufacturing methods thereof. 2. Second Implementation Plan The second embodiment is a second example in which the configuration of the shield is changed in the solid-state imaging device according to the first embodiment. 3. Third Implementation Plan The third embodiment is a third example in which the configuration of the shield is changed in the solid-state imaging device according to the first embodiment. 4. Fourth Implementation Plan The fourth embodiment is a fourth example in which the configuration of the shield is changed in the solid-state imaging device according to the first embodiment. 5. Fifth Implementation Plan The fifth embodiment is a fifth example in which the configuration of the shield is changed in the solid-state imaging device according to the third embodiment. 6. Sixth Implementation Plan The sixth embodiment is a sixth example in which the configuration of the shield is changed in the solid-state imaging device according to the first embodiment. 7. Seventh Implementation Plan The seventh embodiment is a seventh example in which the configuration of the shield is changed in the solid-state imaging device according to the first embodiment. 8. Eighth Implementation Plan The eighth embodiment is an eighth example in which a shield is included in the solid-state imaging device according to the first embodiment. 9. Application Examples of Mobile Objects In this application example, an example in which the present technology is applied to a vehicle control system as an example of a mobile object control system is described. 10. Application Examples of Endoscopic Surgery Systems In this application example, an example in which the present technology is applied to an endoscopic surgery system is described. 11. Other Implementation Options <1. First Implementation Plan>

[0010] Reference Figures 1 to 15 A photodetector 1 according to a first embodiment of the present disclosure is described. Here, in the figures, as appropriate, for convenience, the arrow X direction shown indicates a single planar direction of the photodetector 1 placed on a plane. The arrow Y direction indicates another single planar direction orthogonal to the arrow X direction. Furthermore, the arrow Z direction indicates an upward direction orthogonal to the arrow X and arrow Y directions. That is, the arrow X, arrow Y, and arrow Z directions precisely match the X-axis, Y-axis, and Z-axis directions of the three-dimensional coordinate system, respectively. Furthermore, the direction opposite to the arrow Z direction is the light incident direction L. Note that each of these directions is shown to facilitate understanding of this specification and does not limit the direction of the present technology. [Structure of Photodetector 1] (1) Circuit structure of photodetector 1

[0011] Figure 6 An example of the circuit configuration of the first photoelectric conversion element 3 of the photodetector and the reading circuit 300 thereof according to the first embodiment is shown. Figure 7 An example of a circuit configuration of the second photoelectric conversion element 6 of the photodetector 1 and a reading circuit 600 thereof is shown.

[0012] like Figure 6 and Figure 7 As shown, the photodetector 1 according to the first embodiment has two types including a first photoelectric conversion element 3 and a second photoelectric conversion element 6. Figure 6 As shown, the first photoelectric conversion element 3 is electrically connected to the reading circuit 300. Figure 7 As shown, the second photoelectric conversion element 6 is electrically connected to a reading circuit 600 . Hereinafter, this will be described in detail. (1-1) Circuit Configuration of First Photoelectric Conversion Element 3 and Reading Circuit 300

[0013] like Figure 6 As shown, the first photoelectric conversion element 3 includes a first electrode 31, a photoelectric conversion layer 33, and a second electrode 34. In addition, the first photoelectric conversion element 3 includes a charge accumulation transport layer 32. The first photoelectric conversion element 3 converts incident light into charges.

[0014] Here, the first electrode 31 is provided away from the charge accumulation transport layer 32. The photoelectric conversion layer 33 is stacked on the first electrode 31 and the charge accumulation transport layer 32 and is provided above the first electrode 31 and the charge accumulation transport layer 32. The second electrode 34 is provided on the side of the photoelectric conversion layer 33 opposite to the first electrode 31. The specific materials of the various components of the first photoelectric conversion element 3 and the like will be described in detail later. One or more first photoelectric conversion elements 3 constitute a single pixel 2. In the first embodiment, a total of four first photoelectric conversion elements 3, including two first photoelectric conversion elements 3 adjacent to each other in the arrow X direction and two first photoelectric conversion elements 3 adjacent to each other in the arrow Y direction, constitute a single pixel 2 (refer to Figure 2 ). Note that in the first embodiment, a single pixel 2 may be composed of, for example, two first photoelectric conversion elements 3 , eight first photoelectric conversion elements 3 , or the like.

[0015] The first electrode 31 of the first photoelectric conversion element 3 is electrically connected to a reading circuit 300 with the floating diffusion FD interposed therebetween. The reading circuit 300 can read out the charge converted from light by the first photoelectric conversion element 3. The second electrode 34 is electrically connected to a power supply voltage VOU that supplies a fixed voltage. The charge accumulation transport layer 32 is electrically connected to a drive signal circuit (not shown), and a drive signal VOA is supplied to the charge accumulation transport layer 32 from the drive signal circuit.

[0016] The read circuit 300 includes a reset transistor RST, an amplifier transistor AMP, and a select transistor SEL. One of a pair of main electrodes of the reset transistor RST is electrically connected to the floating diffusion FD, and the other main electrode is electrically connected to the power supply voltage VDD. A reset signal is supplied to the gate electrode. One of the pair of main electrodes of the amplifier transistor AMP is electrically connected to the power supply voltage VDD. The other main electrode is electrically connected to one of the pair of main electrodes of the selection transistor SEL. The floating diffusion portion FD is electrically connected to the gate electrode. The other main electrode of the selection transistor SEL is electrically connected to an output signal line (vertical signal line) VSL. A selection signal is supplied to the gate electrode.

[0017] Transistors such as the reset transistor RST include insulated gate field effect transistors (IGFETs). Examples of IGFETs include metal oxide semiconductor field effect transistors (MOSFETs) and metal insulator semiconductor field effect transistors (MISFETs). (1-2) Circuit Configuration of Second Photoelectric Conversion Element 6 and Reading Circuit 600

[0018] like Figure 7 As shown, the second photoelectric conversion element 6 includes a single-photon avalanche diode (hereinafter, simply referred to as a "SPAD (Single Photon Avalanche Diode)"). The SPAD has a multiplication region that doubles carriers generated by photons. In addition, the SPAD includes an anode region and a cathode region.

[0019] The anode region of the SPAD is supplied with an anode voltage VA. The anode voltage VA is a large negative voltage that causes avalanche multiplication, in other words, a voltage equal to or higher than the breakdown voltage. For example, the anode voltage VA is -20V. The second photoelectric conversion element 6 may be configured by using an avalanche photodiode (APD: Avalanche Photo Diode), a silicon photomultiplier (SiPM: Silicon Photomultiplier), or the like operating in a nonlinear region instead of the SPAD.

[0020] The second photoelectric conversion element 6 is electrically connected to the reading circuit 600. That is, the cathode region of the SPAD is connected to the reading circuit 600. For example, 1 V clamped on the reading circuit 600 side is applied to the cathode region of the second photoelectric conversion element 6. Here, the read circuit 600 includes a quenching element 601, an inverter 602, a counter 603, a phase-locked loop (PLL) 604, and an interface circuit 605. Here, the quenching element 601 draws an avalanche current and puts the read circuit 600 into a reset state. Note that the second photoelectric conversion element 6 may be connected to the reading circuit 600 with a protective circuit (not shown) interposed therebetween.

[0021] Furthermore, the interface circuit 605 is electrically connected to, for example, a time measurement circuit (not shown). The optical detector 1 can construct a distance measurement system including a time measurement circuit. (2) Device Structure of Photodetector 1

[0022] Next, the specific device structure of the photodetector 1 will be described. Figure 1 An example of a vertical cross-sectional configuration corresponding to a single pixel 2 of the photodetector 1 is shown. Figure 2 An example of a planar configuration of the first photoelectric conversion element 3 of the photodetector 1 is shown. Figure 3An example of a planar configuration of the second photoelectric conversion element 6 of the photodetector 1 is shown. Figure 4 An example of a planar configuration of the readout circuit 300 of the photodetector 1 is shown.

[0023] like Figure 1 As shown, the photodetector 1 includes a first substrate 10 and a second substrate 20. The first substrate 10 is stacked on the second substrate 20 along the arrow Z direction. In other words, each of the first substrate 10 and the second substrate 20 is sequentially arranged along the light incident direction L. (2-1) Structure of the First Base 10

[0024] The first base 10 includes a first semiconductor substrate 11 and a first insulating layer 12 provided on a surface 11B of the first semiconductor substrate 11 on a side opposite to the arrow Z direction. In the first embodiment, a single-crystal silicon (Si) substrate is used as the first semiconductor substrate 11. More specifically, the single-crystal Si substrate is formed to have an n-type conductivity, which is the first conductivity type, and a p-type well region, which is the second conductivity type, is formed in a predetermined region of the single-crystal Si substrate. Here, the predetermined region is, for example, the region where the second photoelectric conversion element 6 is provided.

[0025] In addition, as the first semiconductor substrate 11, one or more substrates selected from crystalline Si, amorphous Si, microcrystalline Si, crystalline selenium, amorphous selenium, and CuInGaSe (CIGS), CuInSe2 (CIS), CuInS2, CuAlS2, CuAlSe2, CuGaS2, CuGaSe2, AgAlS2, AgAlSe2, AgInS2, and AgInSe2 which are chalcopyrite-based compounds can be used. In addition, as the first semiconductor substrate 11, one or more compound semiconductor substrates selected from GaAs, InP, AlGaAs, InGaP, AlGaInP, InGaAsP, CdSe, CdS, In2Se3, In2S3, Bi2Se3, Bi2S3, ZnSe, ZnS, PbSe and PbS, which are group III-V compound semiconductors, can be used.

[0026] The first insulating layer 12 electrically isolates the first semiconductor substrate 11 from the second base 20. For example, SiO2 may be used for the first insulating layer 12. (2-2) Structure of the Second Base 20

[0027] The second base 20 includes a second semiconductor substrate 21 and a second insulating layer 22 provided on a surface 21B of the second semiconductor substrate 21 opposite to the arrow Z direction. The first base 10 is stacked on the surface 21A of the second semiconductor substrate 21 along the arrow Z direction. In the first embodiment, a single crystal Si substrate is used for the second semiconductor substrate 21, similarly to the first semiconductor substrate 11. In addition, in the first embodiment, transistors Tr such as the reset transistor RTS constituting the read circuit 300 are provided on the second semiconductor substrate 21. In the second insulating layer 22, wiring 221 and the like are provided.

[0028] In addition, as the second semiconductor substrate 21, one or more substrates selected from crystalline Si, amorphous Si, microcrystalline Si, crystalline selenium, amorphous selenium, and CuInGaSe (CIGS), CuInSe2 (CIS), CuInS2, CuAlS2, CuAlSe2, CuGaS2, CuGaSe2, AgAlS2, AgAlSe2, AgInS2, and AgInSe2 which are chalcopyrite-based compounds can be used. In addition, as the second semiconductor substrate 21, one or more compound semiconductor substrates selected from GaAs, InP, AlGaAs, InGaP, AlGaInP, InGaAsP, CdSe, CdS, In2Se3, In2S3, Bi2Se3, Bi2S3, ZnSe, ZnS, PbSe and PbS, which are group III-V compound semiconductors, can be used. Alternatively, as the second semiconductor substrate 21, a substrate formed using one or more materials selected from quantum dots containing the above-mentioned materials, oxide semiconductor materials such as IGZO, transition metal disulfides, silicon carbide, diamond, graphene, carbon nanotubes, and organic semiconductor materials such as condensed polycyclic hydrocarbon compounds or condensed heterocyclic compounds can be used. For example, IGZO is an oxide semiconductor containing In, G, Zn, and O. That is, when the second semiconductor substrate 21 is formed using a material other than microcrystalline Si, the transistor Tr is formed on a substrate formed using these materials as a base.

[0029] Although not shown in detail, the second insulating layer 22 is formed as an interlayer insulating film provided with a wiring layer of the multilayer wiring 221. For example, for the second insulating layer 22, SiO2 can be used. (2-3) Structure of the First Photoelectric Conversion Element 3

[0030] like Figure 1 As shown, the first photoelectric conversion element 3 is provided on the first substrate 10. More specifically, the first photoelectric conversion element 3 is provided on the surface 11A of the first semiconductor substrate 11 along the arrow Z direction, and the insulating layer 13 is interposed between the first photoelectric conversion element and the surface 11A of the first semiconductor substrate. Figure 1 is simplified, but as Figure 6 and Figure 2As shown, the first photoelectric conversion element 3 includes a first electrode 31 , a photoelectric conversion layer 33 , and a second electrode 34 , and further includes a charge accumulation transport layer 32 . (2-3-1) Structure of the First Electrode 31

[0031] like Figure 1 、 Figure 2 and Figure 6 As shown, the first electrode 31 is provided on the side of the photoelectric conversion layer 33 closer to the first substrate 10. The first electrode 31 serves as a reading electrode or a lower electrode and is arranged for each first photoelectric conversion element 3. The first electrode 31 is connected to the reading circuit 300 via each of the wiring 131 and the through wiring 15 described later. For example, conductive and transparent indium zinc oxide (IZO) or indium tin oxide (ITO) is used for the first electrode 31 . For example, the thickness of the first electrode 31 is 10 nm to 100 nm. (2-3-2) Structure of Photoelectric Conversion Layer 33

[0032] The photoelectric conversion layer 33 is provided in the direction of the arrow Z of the first electrode 31. In the first embodiment, an organic material is used for the photoelectric conversion layer 33. As the organic material, any of a p-type organic semiconductor, an n-type organic semiconductor, a stacked structure of a p-type organic semiconductor and an n-type organic semiconductor, and a hybrid (bulk heterostructure) of a p-type organic semiconductor and an n-type organic semiconductor can be used. The stacked structure includes a stacked structure comprising a p-type organic semiconductor, a mixture of a p-type organic semiconductor and an n-type organic semiconductor (bulk heterostructure), and an n-type organic semiconductor. Furthermore, the stacked structure includes a stacked structure comprising a p-type organic semiconductor and a mixture of a p-type organic semiconductor and an n-type organic semiconductor (bulk heterostructure). Furthermore, the stacked structure includes a stacked structure comprising an n-type organic semiconductor and a mixture of a p-type organic semiconductor and an n-type organic semiconductor (bulk heterostructure). Note that the stacking order of the stacked structure can be appropriately changed.

[0033] As p-type organic semiconductors, naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, pentacene derivatives, quinacridone derivatives, thiophene derivatives, thienothiophene derivatives, benzothiophene derivatives, benzothienothiophene derivatives, triallylamine derivatives, carbazole derivatives, perylene derivatives, chrysene derivatives, fluoranthene derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, subtetraazaporphyrin derivatives, metal complexes using heterocyclic compounds as ligands, polythiophene derivatives, polybenzothiadiazole derivatives, polyfluorene derivatives, etc. can be used.

[0034] As n-type organic semiconductors, fullerenes and fullerene derivatives (for example, fullerenes such as C60, C70 or C74 (higher-order fullerenes), endohedral fullerenes, etc.), fullerene derivatives (for example, fullerene fluorides, PCBM fullerene compounds, fullerene polymers, etc.), organic semiconductors having larger (deeper) HOMO and LUMO than p-type organic semiconductors, or transparent inorganic metal oxides can be used. As n-type organic semiconductors, specifically, heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms can be used. Examples of heterocyclic compounds include organic molecules containing pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, isoquinoline 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, porphyrin derivatives, polyphenylene vinylene derivatives, polybenzothiadiazole derivatives, polyfluorene derivatives, or the like in a portion of the molecular framework, organometallic complexes, or subphthalocyanine derivatives.

[0035] As the groups contained in the fullerene derivative, a halogen atom; a straight-chain, branched or cyclic alkyl group or a phenyl group; a group containing a straight-chain or condensed aromatic compound; a group containing a halide; a partially fluoroalkyl group; a perfluoroalkyl group; a silylalkyl group, a silylalkoxy group; an arylsilyl group; an arylsulfanyl group; an alkylsulfanyl group; an arylsulfonyl group; an alkylsulfonyl group; an allylsulfanyl group; an alkylsulfanyl group; an amino group; an alkylamino group; an arylamino group; a hydroxyl group; an alkoxy group; an acylamino group; an acyloxy group; a carbonyl group; a carboxyl group; an amide group; a carbonylalkoxy group, an acyl group; a sulfonyl group; a cyano group; a nitro group; a group containing a chalcogenide; a phosphino group; a phosphoric acid group and derivatives thereof can be used.

[0036] Although the thickness of the photoelectric conversion layer 33 formed using an organic material is not limited, for example, the thickness is 1×10 -8 m or more and 6×10 -7 The thickness of the photoelectric conversion layer 33 is preferably 1×10 -7 m or more and 4.5×10 -7 m or less. Note that most organic semiconductors are classified as p-type or n-type. P-type means holes are easily transported. N-type means electrons are easily transported. Therefore, the description is not limited to inorganic semiconductors containing holes or electrons as thermally excited majority carriers.

[0037] Then, in the first embodiment, the photoelectric conversion layer 33 generates charges by photoelectrically converting each of the light having a green wavelength and the light having a blue wavelength. When photoelectric conversion is performed on light having a green wavelength, examples of organic materials used to form the photoelectric conversion layer 33 include rhodamine-based pigments, merocyanine-based pigments, quinacridone derivatives, and subphthalocyanine-based pigments (subphthalocyanine derivatives). When photoelectric conversion is performed on light having a blue wavelength, as an organic material forming the photoelectric conversion layer 33 , for example, coumarin acid dye, tris-8-hydroxyquinoline aluminum (Alq 3 ), merocyanine pigment, or the like can be used.

[0038] Furthermore, in the first embodiment, by further adding a configuration that generates light of a red wavelength through photoelectric conversion, the photoelectric conversion layer 33 can extract information across the entire visible light range. When photoelectric conversion is performed on light of a red wavelength, for example, a phthalocyanine pigment or a subphthalocyanine pigment (subphthalocyanine derivative) can be used as the organic material forming the photoelectric conversion layer 33.

[0039] In addition, the photoelectric conversion layer 33 may be constructed using an inorganic photoelectric conversion layer. In this case, as the inorganic material for constructing the inorganic photoelectric conversion layer, one or more selected from crystalline Si, amorphous Si, microcrystalline Si, crystalline selenium, amorphous selenium, chalcopyrite-based compounds, and Group III-V compound semiconductors may be used. The chalcopyrite-based compounds include CuInGaSe (CIGS), CuInSe2 (CIS), CuInS2, CuAlS2, CuAlSe2, CuGaS2, CuGaSe2, AgAlS2, AgAlSe2, AgInS2 or AgInSe2. Group III-V compound semiconductors include GaAs, InP, AlGaAs, InGaP, AlGaInP, InGaAsP, etc. Group III-V compound semiconductors include CdSe, CdS, In2Se3, In2S3, Bi2Se3, Bi2S3, ZnSe, ZnS, PbSe, PbS, etc. In addition, quantum dots including these materials can be used for the photoelectric conversion layer 33 .

[0040] Although not shown, the photoelectric conversion layer 33 may have a stacked structure of a lower semiconductor layer and an upper photoelectric conversion layer. By including the lower semiconductor layer in the photoelectric conversion layer 33, the photoelectric conversion layer 33 can prevent recombination during charge accumulation and improve the efficiency of charge transfer to the charge accumulation and transport layer 32. Furthermore, the generation of dark current can be effectively suppressed.

[0041] As the upper photoelectric conversion layer, a material can be appropriately selected from the various materials forming the above-mentioned photoelectric conversion layer 33 . On the other hand, as the lower semiconductor layer, it is preferable to use a material having a large band gap value (for example, a band gap value equal to or greater than 3.0 eV) and higher mobility than the material forming the photoelectric conversion layer 33. Specifically, oxide semiconductor materials such as IGZO, transition metal disulfide, silicon carbide, diamond, graphene, carbon nanotubes, and organic semiconductor materials such as condensed polycyclic hydrocarbon compounds or condensed heterocyclic compounds can be used. Furthermore, when the accumulated charges are electrons, a material having an ionization potential greater than that of the material forming the photoelectric conversion layer 33 can be used as the lower semiconductor layer.

[0042] On the other hand, when the accumulated charges are holes, a material having an electron affinity lower than that of the material forming the photoelectric conversion layer 33 can be used as the lower semiconductor layer. In addition, the material forming the lower semiconductor layer preferably has an impurity concentration of not more than 1×10 18 cm -3 The lower semiconductor layer may have a single-layer structure or a multi-layer structure. In addition, the material forming the lower semiconductor layer may be different for each of the region corresponding to the first electrode 31 and the region corresponding to the floating diffusion FD. (2-3-3) Structure of the Second Electrode 34

[0043] The second electrode 34 is provided on the opposite side of the photoelectric conversion layer 33 from the first electrode 31. The second electrode 34 serves as a common electrode or an upper electrode, and is arranged on the plurality of first photoelectric conversion elements 3 and the plurality of pixels 2. Similar to the first electrode 31, the second electrode 34 is formed using an electrode material having conductivity and transparency. The second electrode 34 is formed using, for example, an electrode material such as ITO or IZO. Furthermore, the second electrode 34 can be formed using one or more electrode materials selected from IGZO, IAZO, ITZO, IGSiO, ZnO, AZO, and GZO. The film thickness of the second electrode 34 is, for example, not less than 10 nm and not more than 100 nm. (2-3-4) Structure of the Charge Accumulation and Transport Layer 32

[0044] The charge accumulation and transport layer 32 is provided between the first electrode 31 and the photoelectric conversion layer 33. More specifically, the photoelectric conversion layer 33 is provided on the first electrode 31 with an insulator (reference numeral omitted) interposed therebetween. Here, the charge accumulation and transport layer 32 is provided on the plurality of pixels 2. Here, an insulator (reference numeral omitted) is used as the gate insulating film. As the insulator, for example, one or more insulating materials selected from SiO 2 , SiON, AlO, and HfO are used.

[0045] The charge accumulation transport layer 32 accumulates charges generated by photoelectric conversion of light by the photoelectric conversion layer 33. The drive signal VOA is supplied to the charge accumulation transport layer 32 via each of the wiring 131 and the through wiring 15.

[0046] The charge accumulation transport layer 32 is formed using an oxide semiconductor that is a transparent semiconductor. More specifically, for example, IGZO is used for the charge accumulation transport layer 32. Furthermore, for the charge accumulation transport layer 32, IAZO containing In, Al, Zn, and O, or ITZO containing In, Sn, Zn, and O can be used. Furthermore, for the charge accumulation transport layer 32, one or more semiconductor materials selected from IGSiO, ZnO, AZO, GZO, ITO, and IZO can be used. The thickness of the charge accumulation transport layer 32 is, for example, not less than 10 nm and not more than 100 nm. (2-4) Structure of the Filter 4

[0047] like Figure 1 and Figure 2 As shown, the optical filter 4 is provided with a protective film (reference numerals omitted) interposed therebetween in the direction of arrow Z of the first photoelectric conversion element 3 . The optical filter 4 is provided for each first photoelectric conversion element 3 .

[0048] The planar shape of a single pixel 2 is a rectangle (hereinafter referred to as “plan view”) when viewed from the direction of incident light L. The planar shape of the first photoelectric conversion element 3 is a rectangle smaller than and similar to the pixel 2 . In a single pixel 2, an optical filter 4 that transmits light of a green wavelength is arranged on two first photoelectric conversion elements 3 arranged along a diagonal line. The optical filter 4 is denoted by reference symbol "G". Furthermore, in a single pixel 2, an optical filter 4 that transmits light of a blue wavelength is arranged on two first photoelectric conversion elements 3 arranged in another diagonal direction. This optical filter 4 is denoted by reference symbol "B".

[0049] The optical filter 4 is formed by, for example, including a pigment for coloring a resin material. More specifically, as the resin, an organic resin material such as a phthalocyanine derivative can be used.

[0050] Furthermore, a spacer 40 is provided between the filters 4. The spacer 40 is formed so as to surround the periphery of the side surface of the filter 4. The spacer 40 can effectively suppress or prevent light from leaking from one of the adjacent filters 4 to the other filter 4. (2-5) Structure of Optical Lens 5

[0051] like Figure 1 As shown, the optical lens 5 is provided on the side of the filter 4 opposite to the first photoelectric conversion element 3. Although not shown, in a plan view, the optical lens 5 is formed into a circular shape for each first photoelectric conversion element 3. In addition, the optical lens 5 is formed into a curved shape that curves toward the light incident direction L when viewed in the direction of arrow Y (hereinafter simply referred to as a "side view"), and collects incident light. That is, the optical lens 5 is a so-called on-chip lens, and is integrally formed over the plurality of first photoelectric conversion elements 3. The optical lens 5 is formed using, for example, a transparent resin material. (2-6) Structure of the Second Photoelectric Conversion Element 6

[0052] like Figure 1 and Figure 3 As shown, in the region of the pixel 2, the second photoelectric conversion element 6 is provided in the first semiconductor substrate 11 of the first base 10, overlapping with the first photoelectric conversion element 3. That is, the first photoelectric conversion element 3 is stacked on the second photoelectric conversion element 6 in the light incident direction L. In other words, the first photoelectric conversion element 3 and the second photoelectric conversion element 6 are each stacked vertically in the arrow Z direction. Then, a partition 7 is provided along and surrounding the side surface of the second photoelectric conversion element 6. The partition 7 is arranged between the pixels 2 in a plan view, and electrically and optically separates the adjacent second photoelectric conversion elements 6.

[0053] In the first embodiment, the second photoelectric conversion element 6 is a SPAD and includes an anode region 62 and a cathode region 63 .

[0054] The anode region 62 is provided in the well region 61 formed on the first semiconductor substrate 11 in the peripheral region on the side of the surface 11B of the first semiconductor substrate 11, and is provided along the partition 7. The well region 61 is provided as a p-type, and the anode region 62 is formed using a p-type semiconductor region having a higher impurity concentration than the well region 61. Although detailed explanation is omitted, the anode voltage VA is supplied to the anode region 62 via wiring. The cathode region 63 is provided on one side of the surface 11B of the first semiconductor substrate 11 in the middle region of the well region 61. The cathode region 63 is formed using an n-type semiconductor region and is supplied with a cathode voltage.

[0055] like Figure 1As shown, in the second photoelectric conversion element 6, a multiplication region 6A is formed at the junction between the anode region 62 and the cathode region 63. In the multiplication region 6A, carriers (here, electrons) Lc generated by input photons Lp can be multiplied.

[0056] Furthermore, a drift region 64 is provided in the middle region of the well region 61, facing the surface 11A side of the first semiconductor substrate 11. The drift region 64 is formed using an n-type semiconductor region, and relaxes the drift field. (2-7) Structure of the partition 7

[0057] The partition 7 includes a groove 71 and a buried body 72. Note that in the well region 61, a pinning region 65 is provided along the partition 7. The pinning region 65 is formed using a p-type semiconductor region having a higher impurity concentration than the well region 61. In a plan view, the groove 71 is provided along and surrounds the side surface of the second photoelectric conversion element 6. In a side view, the groove 71 is formed to extend from the surface 11A toward the surface 11B of the first semiconductor substrate 11 in its thickness direction.

[0058] The embedded body 72 is embedded in the groove 71. The embedded body 72 is formed using an insulating material that electrically isolates at least adjacent second photoelectric conversion elements 6. In the first embodiment, SiO2 is used as the embedded body 72.

[0059] In addition, the buried body 72 may be formed using one or more insulating materials selected from tetraethoxysilane (TEOS), SiN, and SiON. Furthermore, as the embedded body 72 , one or more materials selected from hafnium oxide (HfO), aluminum oxide (AlO), zirconium oxide (ZrO), tantalum oxide (TaO), and titanium oxide (TiO) can be used. In addition, as an insulating material other than the above-mentioned materials, the buried body 72 may include one or more materials selected from the group consisting of lanthanum oxide (LaO), praseodymium oxide (PrO), cerium oxide (CeO), neodymium oxide (NdO), promethium oxide (PmO), samarium oxide (SmO), europium oxide (EuO), gadolinium oxide (GaO), terbium oxide (TbO), dysprosium oxide (DyO), holmium oxide (HoO), thulium oxide (TmO), ytterbium oxide (YbO), lutetium oxide (LuO), yttrium oxide (YO), aluminum nitride (AlN), hafnium oxynitride (HfON), and aluminum oxynitride (AlON). (2-8) Structure of Wiring 131 and Filter 132

[0060] On the surface 11A of the first semiconductor substrate 11 of the first base 10, the first photoelectric conversion element 3 is provided via the insulating layer 13. In the insulating layer 13, a multilayer wiring 131 is provided on one side of the first photoelectric conversion element 3, and a filter 132 is provided on the second photoelectric conversion element 6 side.

[0061] The insulating layer 13 is formed using, for example, an insulating material similar to that of the first insulating layer 12 . One end of the wiring 131 is electrically connected to the first photoelectric conversion element 3. Furthermore, the other end of the wiring 131 is electrically connected to a through wiring 15 described later. For the wiring 131, the above-described transparent electrode material is used.

[0062] Here, a single filter 132 is provided for four first photoelectric conversion elements 3 of a single pixel 2. The planar shape of the filter 132 is formed in a rectangular shape (not shown). The optical filter 132 transmits infrared light and is denoted by reference symbol "IR". The optical filter 132 is formed using a material similar to that of the optical filter 4 . (2-9) Structure of Through Wiring 15

[0063] like Figure 1 and Figure 3 As shown, a plurality of through-wirings 15 arranged at regular intervals are provided along the periphery of the second photoelectric conversion element 6. One end of the through-wiring 15 is electrically connected to the first photoelectric conversion element 3 via a wiring 131. The other end of the through-wiring 15 passes through at least the first semiconductor substrate 11 of the first base 10 in the thickness direction and is electrically connected to the reading circuit 300. More specifically, the through-wiring 15 extends to pass through the buried body 72 of the partition 7.

[0064] Here, as Figure 3 As shown, through wirings 15 provided on the left and right sides of the pixel 2 in plan view and denoted by reference symbol "FD" serve as floating diffusions FD. The through wirings 15 other than the above are used as signal lines for supplying drive signals VOA and the like.

[0065] A conductive Si material or a metal material is used for the through wiring 15. As the Si material, for example, a Si material doped with impurities to achieve conductivity, such as phosphorus-doped amorphous silicon (PDAS), can be used. As the metal material, for example, one or more metal materials selected from the group consisting of Al, tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta) can be used.

[0066] Note that the through wiring 15 may be connected to the reading circuit 600 , and in the present technology, one or both of the “reading circuit 300 ” and the “reading circuit 600 ” may be collectively referred to simply as a “circuit”. (2-10) Structure of light-shielding body 8

[0067] Figure 5 Shown as Figure 1 An example of an enlarged vertical cross-sectional structure of the light shielding body 8 of the main portion of the photodetector 1 is shown. like Figure 1 、 Figure 3 and Figure 5 As shown, the photodetector 1 includes a light-shielding body 8. The light-shielding body 8 is provided along the periphery of the second photoelectric conversion element 6 so as to surround the side surfaces of the second photoelectric conversion element 6 in plan view and side view.

[0068] More specifically, the light-shielding body 8 is provided between the second photoelectric conversion element 6 and the through-wiring 15 and is formed along the sidewall of the groove 71 of the partition 7. The light-shielding body 8 is formed so as to extend through at least the first semiconductor substrate 11 of the first base 10 in the thickness direction. In other words, the light-shielding body 8 is formed using the groove 71 of the partition 7 .

[0069] In the first embodiment, the light-blocking body 8 passes through the first semiconductor substrate 11 of the first base 10 in the thickness direction, further passes through the first insulating layer 12 of the first base 10 in the thickness direction, and extends into the second semiconductor substrate 21 of the second base 20. The position of one end of the light-blocking body 8 in the direction of arrow Z coincides with the surface 11A of the first semiconductor substrate 11. The element separator 210 that electrically isolates the transistors Tr is provided in the second semiconductor substrate 21. The position of the other end of the light-blocking body 8, on the side opposite to the direction of arrow Z, coincides with the bottom surface of the element separator 210 on the side of the direction of arrow Z.

[0070] The light shield 8 blocks the carriers Lc generated from the second photoelectric conversion element 6 and effectively suppresses or prevents the carriers Lc from leaking to the adjacent second photoelectric conversion element 6. In addition, since the light shield 8 also extends to one side of the second substrate 20, the leakage of the carriers Lc to the transistor Tr is effectively suppressed or prevented.

[0071] The light-shielding body 8 includes a metal material having a better reflective property or light-shielding property than the carriers Lc. As such a metal material, for example, one or more metal materials selected from Al, W, Ti, Co, Hf, Ag, and Ta can be used. (2-11) Configuration of the Read Circuit 300

[0072] For ease of explanation, Figure 1 and Figure 4As shown, on the second semiconductor substrate 21 of the second base 20, a transistor Tr constituting the reading circuit 300 is provided. As described above, in the first embodiment, four first photoelectric conversion elements 3 are arranged for a single pixel 2. Therefore, as shown in FIG. Figure 4 As shown, on the second semiconductor substrate 21 , four pairs of a reset transistor RST, an amplifier transistor AMP, and a selection transistor SEL are provided corresponding to the individual first photoelectric conversion elements 3 .

[0073] Note that Figure 5 As shown, the element separation portion 210 provided between the transistors Tr includes a groove 211 formed from the surface 21B toward the surface 21A of the second semiconductor substrate 21 and an insulator 212 buried in the groove 211 and having an insulating property. [Method of Manufacturing Photodetector 1]

[0074] Next, refer to Figures 8 to 15 A method for manufacturing the above-mentioned photodetector 1 will be described. Figures 8 to 15 An example of a cross section for explaining a series of processes of the method for manufacturing the photodetector 1 according to the first embodiment is shown.

[0075] First, if Figure 8 As shown, the second substrate 20 is stacked on the first substrate 10, and the second photoelectric conversion element 6 of the first substrate 10 and the wiring 221 of the second substrate 10 are electrically connected to each other. Figures 8 to 15 , only the main parts are shown, but in the first base 10, the second photoelectric conversion element 6 is formed on the first semiconductor substrate 11, and the first insulating layer 12 is formed. In addition, in the second base 20, the transistor Tr is formed on the second semiconductor substrate 21, and the second insulating layer 22 is formed.

[0076] The second base 20 is bonded to a supporting substrate (not shown), and as Figure 9 As shown, the first semiconductor substrate 11 of the first base 10 is thinned. For example, a chemical mechanical polishing (CMP) method is used for this thinning.

[0077] like Figure 10 As shown, a groove 71 of the partition 7 is formed in the first substrate 10 and the second substrate 20 around the pixel 2 formation region. The groove 71 extends from the surface 11A of the first semiconductor substrate 11 of the first substrate 10 through the first semiconductor substrate 10 and the first insulating layer 12 in the thickness direction and is formed to reach the interior of the second semiconductor substrate 21 of the second substrate 20. Here, the groove 71 is formed to reach the bottom surface of the element separation section 210 of the second substrate 20. To form the groove 71, an anisotropic etching method such as a reactive ion etching (RIE) method is used. In other words, the element separation portion 210 functions as an etching stopper when forming the groove 71 .

[0078] like Figure 11 As shown, a first buried body 72 is formed along the inner wall and bottom surface of the groove 71. As described above, the buried body 72 is formed using, for example, SiO2. The buried body 72 is formed, for example, by an atomic layer deposition (ALD) method.

[0079] like Figure 12 As shown, light shielding member 8 is formed at least along the inner wall of groove 71, with embedded member 72 interposed therebetween. For example, Al, which has high light reflectivity, is used for light shielding member 8. Light shielding member 8 is formed, for example, by ALD or chemical vapor deposition (CVD).

[0080] like Figure 13 As shown, a second embedded body 72 is formed along the inner wall and bottom surface of the groove 71 with the light shielding body 8 interposed therebetween. The embedded body 72 is formed using the same insulating material as the first embedded body 72. Alternatively, the embedded body 72 may be formed using a different insulating material from the first embedded body 72.

[0081] like Figure 14 As shown, a groove 73 is formed in the middle portion of the groove 71 in the groove width direction, passing through each of the element separation unit 210 and the second semiconductor substrate 21 in the thickness direction and reaching the wiring 221. For example, the groove 73 is formed by an anisotropic etching method. Then, an insulating film (reference numeral omitted) is formed to perform insulation and separation from the light shielding body 8.

[0082] like Figure 15 As shown, a through wiring 15 is formed, which is buried in the groove 73 and reaches the wiring 221 of the second substrate 20 from the surface 11A of the first semiconductor substrate 11 of the first base 10. For example, the through wiring 15 is formed using Al. The through wiring 15 is formed by the ALD method or the CVD method. Note that unnecessary through wiring 15 formed on the surface 11A of the first semiconductor substrate 11 is removed by an etch-back method or the like.

[0083] Then, on the surface 11A of the first semiconductor substrate 11 of the first base 10, the filter 132, the wiring 131, the first photoelectric conversion element 3, the filter 4 and the optical lens 5 are formed in order. When this process is completed, the above-mentioned Figures 1 to 5 The light detector 1 is shown. [Function and Effect]

[0084] As mentioned above, Figure 1 As shown, the photodetector 1 according to the first embodiment includes a first photoelectric conversion element 3 and a second photoelectric conversion element 6 . The first photoelectric conversion element 3 is provided on the light incident side of the first substrate 10 and converts incident light into electric charges. The second photoelectric conversion element 6 is provided overlapping with the first photoelectric conversion element 3 in the first substrate 10 and includes a multiplication region 6A that multiplies carriers generated by light. In other words, the first photoelectric conversion element 3 is stacked on the second photoelectric conversion element 6 in the light incident direction L. In this structured photodetector 1, the first photoelectric conversion element 3 photoelectrically converts visible light, and the second photoelectric conversion element 6 photoelectrically converts infrared light. This allows the acquisition of both visible light information and distance measurement information. Consequently, the photodetector 1 can achieve a wide and improved distance measurement range. Furthermore, the photodetector 1 can improve the signal-to-noise ratio (S / N ratio) when acquiring distance measurement information, further expanding the dynamic range.

[0085] In addition, if Figure 1 、 Figure 3 and Figure 5 As shown, the photodetector 1 includes a light-shielding body 8. The light-shielding body 8 is provided along the periphery of the second photoelectric conversion element 6 in a plan view and passes through at least the first semiconductor substrate 11 in the thickness direction. Furthermore, the light-shielding body 8 is provided between the second photoelectric conversion element 6 and the through-wiring 15. The light-shielding body 8 blocks carriers Lc generated from the second photoelectric conversion element 6. According to the photodetector 1 configured in this manner, the carriers Lc generated from the second photoelectric conversion element 6 can be blocked by the light shielding body 8. Therefore, leakage of the carriers Lc to the adjacent pixels 2 can be effectively suppressed or prevented.

[0086] Furthermore, in the photodetector 1, as Figure 1 and Figure 5 As shown, the light shielding body 8 extends into the second semiconductor substrate 21 of the second base 20 . Therefore, the light shielding body 8 can effectively suppress or prevent the carriers Lc generated in the second photoelectric conversion element 6 from leaking toward the second semiconductor substrate 21. That is, malfunctions of the reading circuit 300 and the like caused by the leakage of the carriers Lc can be effectively suppressed or prevented.

[0087] Furthermore, in the method for manufacturing the photodetector 1, as Figure 11 and Figure 12 As shown, the light shielding body 8 is formed using the groove 71 of the partition 7. Therefore, in the photodetector 1, the light shielding body 8 can be easily constructed.

[0088] In addition, if Figure 1 、 Figure 3 and Figure 5 As shown, the photodetector 1 includes a first substrate 10 , a second photoelectric conversion element 6 , and a light shielding body 8 . The first base 10 includes a first semiconductor substrate 11 and a first insulating layer 12 stacked on the first semiconductor substrate 11. The second photoelectric conversion element 6 is provided in the first base 10 and includes a multiplication region 6A that multiplies carriers Lc generated by light. The light-blocking body 8 is provided along the periphery of the second photoelectric conversion element 6 in a plan view, passes through at least the first semiconductor substrate 11 in the thickness direction, and blocks carriers generated by the second photoelectric conversion element 6. According to the photodetector 1 configured in this manner, the carriers Lc generated from the second photoelectric conversion element 6 can be blocked by the light shielding body 8. Therefore, the leakage of the carriers Lc to the adjacent pixels 2 can be effectively suppressed or prevented. <2. Second Implementation Plan>

[0089] Reference Figure 16 A photodetector 1 according to a second embodiment of the present disclosure will be described. Note that, in the second and subsequent embodiments, components that are the same as or substantially the same as those of the photodetector 1 according to the first embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted. [Structure of Photodetector 1]

[0090] Figure 16 An example of an enlarged vertical cross-sectional configuration of a light-shielding body 8 as a main portion of the photodetector 1 according to the second embodiment is shown. like Figure 16 As shown, in the photodetector 1 according to the second embodiment, the light-shielding body 8 passes through the second semiconductor substrate 21 of the second base 20 in the thickness direction and extends to the wiring 221 of the second insulating layer 22. In other words, the light-shielding body 8 completely passes through the second semiconductor substrate 21 in the thickness direction.

[0091] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the first embodiment. [Function and Effect]

[0092] The photodetector 1 according to the second embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to the first embodiment.

[0093] Furthermore, in the photodetector 1, as Figure 16 As shown, the light-shielding body 8 completely passes through the second semiconductor substrate 21 along the thickness direction. Therefore, the light shielding body 8 can more effectively suppress or prevent the carriers Lc generated from the second photoelectric conversion element 6 from leaking to the second semiconductor substrate 21 , and can more effectively suppress or prevent malfunctions of the reading circuit 300 and the like caused by the leakage of the carriers Lc. <3. Third Implementation Plan>

[0094] Reference Figure 17 A photodetector 1 according to a third embodiment of the present disclosure will be described. [Structure of Photodetector 1]

[0095] Figure 17 An example of an enlarged vertical cross-sectional configuration of a light-shielding body 8 as a main portion of the photodetector 1 according to the third embodiment is shown. like Figure 17 As shown, in the photodetector 1 according to the third embodiment, the light shielding body 8 completely penetrates the second semiconductor substrate 21 of the second base 20 in the thickness direction. The light shielding body 8 extends to a predetermined position of the second insulating layer 22, not limited to the wiring 221.

[0096] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the second embodiment. [Function and Effect]

[0097] The photodetector 1 according to the third embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to the second embodiment. <4. Fourth Implementation Plan>

[0098] Reference Figure 18 A photodetector 1 according to a fourth embodiment of the present disclosure is described. [Structure of Photodetector 1]

[0099] Figure 18 An example of an enlarged vertical cross-sectional configuration of a light-shielding body 8 as a main portion of the photodetector 1 according to the fourth embodiment is shown. like Figure 18 As shown, in the photodetector 1 according to the fourth embodiment, the light-shielding body 8 extends into the first insulating layer 12 of the first substrate 10. In other words, the light-shielding body 8 does not reach the second substrate 20.

[0100] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the second embodiment. [Function and Effect]

[0101] The photodetector 1 according to the fourth embodiment can obtain operations and effects similar to those obtained by the photodetector 1 according to the first embodiment.

[0102] Furthermore, in the photodetector 1, as Figure 18 As shown, the light-shielding body 8 extends only into the first insulating layer 12 of the first substrate 10 and does not reach the second substrate 20 . Therefore, the layout of the light-shielding body 8 does not affect the second substrate 20. That is, the element layout of the reading circuit 300 of the second substrate 20 is freely performed with respect to the layout of the light-shielding body 8. <5. Fifth Implementation Plan>

[0103] Reference Figure 19 and Figure 20 A photodetector 1 according to a fifth embodiment of the present disclosure will be described. [Structure of Photodetector 1] Figure 19 An example of an enlarged vertical cross-sectional configuration of a light-shielding body 8 as a main portion of the photodetector 1 according to the fifth embodiment is shown. Figure 20 An example of a planar configuration of the light-shielding body 8 is shown.

[0104] like Figure 19 and Figure 20 As shown, in the photodetector 1 according to the fifth embodiment, in a plan view, a plurality of through wirings 15 are arranged along the periphery of the second photoelectric conversion element 6. When viewed from the second photoelectric conversion element 6, one through wiring 15 and another through wiring 15 adjacent to each other in the arrangement direction are arranged so that their respective portions overlap each other. In other words, the plurality of through-wirings 15 are arranged without gaps therebetween when viewed from the middle of the pixel 2. That is, the through-wirings 15 constitute the light-shielding body 8 described in the photodetector 1 according to the first to fourth embodiments.

[0105] In the fifth embodiment, similarly to the light-shielding body 8 of the photodetector 1 according to the third embodiment, the light-shielding body 8 extends into the second insulating layer 22 of the second substrate 20 (refer to Figure 17 ). Note that, similar to the light-shielding body 8 of the photodetector 1 according to the first embodiment, the light-shielding body 8 may extend into the second semiconductor substrate 21 (see Figure 5 ). In addition, similar to the light-shielding body 8 of the photodetector 1 according to the second embodiment, the light-shielding body 8 may extend into the first insulating layer 12 of the first substrate 10 (refer to Figure 18 ).

[0106] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the first to fourth embodiments. [Function and Effect]

[0107] The photodetector 1 according to the fifth embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to any one of the first to fourth embodiments.

[0108] Furthermore, in the photodetector 1, as Figure 19 and Figure 20 As shown, in a plan view, a plurality of through wirings 15 are arranged along the periphery of the second photoelectric conversion element 6 and form a light-shielding body 8 that blocks carriers generated by the second photoelectric conversion element 6. Therefore, since the through wirings 15 can be used as the light-shielding body 8, the light-shielding body 8 can be easily constructed. <6. Sixth Implementation Plan>

[0109] Reference Figure 21 and Figure 22 A photodetector 1 according to a sixth embodiment of the present disclosure is described. [Structure of Photodetector 1]

[0110] Figure 21 An example of an enlarged vertical cross-sectional configuration of a light-shielding body 8 as a main portion of the photodetector 1 according to the sixth embodiment is shown. Figure 22 An example of a planar configuration of the light-shielding body 8 is shown.

[0111] like Figure 21 and Figure 22 As shown, in the photodetector 1 according to the sixth embodiment, a portion of the embedded body 72 of the partition 7 between the through wiring 15 and the light shielding body 8 is formed as a first insulator 721. The first insulator 721 has a higher dielectric strength than the first insulating layer 12. Under such conditions, the first insulator 712 is appropriately selected from the materials described as the embedded body 72 of the photodetector 1 according to the first embodiment.

[0112] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the first to fourth embodiments. [Function and Effect]

[0113] The photodetector 1 according to the sixth embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to any one of the first to fourth embodiments.

[0114] Furthermore, in the photodetector 1, the first insulator 721 is provided between the through wiring 15 and the light-blocking body 8. Therefore, the dielectric strength between the through wiring 15 and the light-blocking body 8 can be improved. <7. Seventh Implementation Plan>

[0115] Reference Figure 23 A photodetector 1 according to a seventh embodiment of the present disclosure is described. [Structure of Photodetector 1]

[0116] Figure 23 An example of a planar configuration of the light-shielding body 8 as a main portion of the photodetector 1 according to the sixth embodiment is shown.

[0117] like Figure 23 As shown, in the photodetector 1 according to the seventh embodiment, a portion of the embedded body 72 of the partition 7 between the through wiring 15 and the light shielding body 8 is formed as a second insulator 722. The second insulator 722 has a lower dielectric constant than the first insulating layer 12. Under such conditions, the second insulator 722 is appropriately selected from the materials described as the embedded body 72 of the photodetector 1 according to the first embodiment.

[0118] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the first to fourth embodiments. [Function and Effect]

[0119] The photodetector 1 according to the seventh embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to any one of the first to fourth embodiments.

[0120] Furthermore, in the photodetector 1, a second insulator 722 having a low dielectric constant is provided between the through-wiring 15 and the light shielding body 8. Therefore, the parasitic capacitance applied to the through-wiring 15 can be reduced. In particular, since the through-wiring 15 functions as the floating diffusion FD, the photoelectric conversion efficiency can be improved (see FIG. Figure 6 ). <8. Eighth Implementation Plan>

[0121] Reference Figure 24 A photodetector 1 according to an eighth embodiment of the present disclosure is described. [Structure of Photodetector 1]

[0122] Figure 24 An example of a planar configuration of the photodetector 1 according to the eighth embodiment is shown.

[0123] In the photodetector 1 according to the eighth embodiment, as Figure 24 As shown, a cathode electrode 225 (see FIG. 2 ) electrically connected to the cathode region 63 of the SPAD serving as the second photoelectric conversion element 6 is drawn around the reading circuit 300. Figure 1 Here, a shield 226 surrounding the cathode electrode 225 is provided between the readout circuit 300 and the cathode electrode 225 . The shield 226 has an electrode structure similar to that of the cathode electrode 225 .

[0124] In the eighth embodiment, a plurality of shields 226 are arranged in the direction of arrow X. A fixed potential is supplied to the shields 226. For example, the fixed potential is 0V or higher and 3V or lower. Note that a plurality of shielding bodies 226 may be integrally formed.

[0125] Components other than those described above are the same or substantially the same as those of the photodetector 1 according to the first to seventh embodiments. [Function and Effect]

[0126] The photodetector 1 according to the eighth embodiment can obtain similar actions and effects to those obtained by the photodetector 1 according to any one of the first to seventh embodiments.

[0127] Furthermore, in the photodetector 1, as Figure 24 As shown, a shield 226 is provided that surrounds the cathode electrode 225 of the second photoelectric conversion element 6 and is applied with a fixed potential. Therefore, the influence of the cathode voltage applied to the cathode electrode on the surrounding environment can be effectively suppressed or prevented. <9. Application Examples of Mobile Objects>

[0128] The technology disclosed herein (the present technology) is applicable to a variety of products. For example, the technology disclosed herein can be implemented as a device mounted on any mobile device, such as an automobile, electric vehicle, hybrid vehicle, motorcycle, bicycle, personal mobility device, airplane, drone, ship, or robot.

[0129] Figure 25 is a block diagram showing a schematic configuration example of a vehicle control system as an example of a mobile body control system to which the technology according to the embodiment of the present disclosure can be applied.

[0130] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Figure 25 In the illustrated example, vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an exterior information detection unit 12030, an interior information detection unit 12040, and an integrated control unit 12050. Furthermore, the functional components of integrated control unit 12050 include a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053.

[0131] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various types of programs. For example, the drive system control unit 12010 functions as a control device for the following devices: a drive force generating device such as an internal combustion engine or a drive motor for generating vehicle drive force; a drive force transmission mechanism for transmitting drive force to wheels; a steering mechanism for adjusting the vehicle's steering angle; a braking device for generating vehicle braking force; and the like.

[0132] The body system control unit 12020 controls the operation of various devices installed on 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, power windows, and various lights such as the headlights, backup lights, brake lights, turn signals, and fog lights. In this case, the body system control unit 12020 can receive radio waves or signals from various switches transmitted from a mobile device that replaces a key. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door locks, power windows, lights, and other functions.

[0133] The vehicle exterior information detection unit 12030 detects information about the exterior of the vehicle, including the vehicle control system 12000. For example, the vehicle exterior information detection unit 12030 is connected to the imaging unit 12031. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture images of the exterior of the vehicle and receives the captured images. Based on the received images, the vehicle exterior information detection unit 12030 can detect objects such as people, vehicles, obstacles, signs, and characters on the road surface, or can detect the distance to such objects.

[0134] 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 can be visible light or invisible light such as infrared light.

[0135] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver status detection unit 12041 that detects the driver's condition. For example, the driver status detection unit 12041 includes a camera that captures the driver's image. Based on the detection information input from the driver status detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or determine whether the driver is dozing off.

[0136] Microcomputer 12051 can calculate control target values ​​for the driving force generation device, steering mechanism, or braking device based on information about the vehicle's exterior or interior obtained by vehicle exterior information detection unit 12030 or vehicle interior information detection unit 12040, and output control commands to drive system control unit 12010. For example, microcomputer 12051 can perform coordinated control to implement advanced driver assistance system (ADAS) functions, including collision avoidance or impact mitigation, vehicle-to-vehicle distance-based following driving, speed maintenance driving, vehicle collision warning, and vehicle lane departure warning.

[0137] In addition, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information outside or inside the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 is able to perform collaborative control aimed at achieving automatic driving, etc., wherein the automatic driving enables the vehicle to drive autonomously without relying on the driver's operation.

[0138] In addition, based on the information outside the vehicle obtained by the vehicle exterior information detection unit 12030, the microcomputer 12051 can output a control command to the body system control unit 12020. For example, the microcomputer 12051 can perform cooperative control aimed at preventing glare by controlling the headlights to switch from high beam to low beam, for example, based on the position of a preceding vehicle or an oncoming vehicle detected by the vehicle exterior information detection unit 12030.

[0139] The sound / image output unit 12052 sends an output signal of at least one of sound and image to an output device capable of visually or auditorily notifying the vehicle's passengers or the outside of the vehicle of information. Figure 25 In the example of FIG, as the output device, an audio speaker 12061, a display portion 12062, and an instrument panel 12063 are shown. For example, the display portion 12062 may include at least one of an in-vehicle display and a head-up display.

[0140] Figure 26 12031 is a diagram showing an example of the installation position of the camera unit 12031.

[0141] exist Figure 26 , the camera unit 12031 includes camera units 12101 , 12102 , 12103 , 12104 and 12105 .

[0142] Camera units 12101, 12102, 12103, 12104, and 12105 are located, for example, on the front nose, rearview mirror, rear bumper, and rear door of vehicle 12100, as well as on the upper portion of the windshield inside the vehicle. Camera unit 12101 located on the front nose and camera unit 12105 located on the upper portion of the windshield inside the vehicle primarily capture images in front of vehicle 12100. Camera units 12102 and 12103 located on the rearview mirror primarily capture images on both sides of vehicle 12100. Camera unit 12104 located on the rear bumper or rear door primarily captures images from behind vehicle 12100. Camera unit 12105 located on the upper portion of the windshield inside the vehicle primarily detects vehicles ahead, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

[0143] By the way, Figure 26Examples of the imaging ranges of imaging units 12101 through 12104 are shown. Imaging range 12111 represents the imaging range of imaging unit 12101, located on the front nose. Imaging ranges 12112 and 12113 represent the imaging ranges of imaging units 12102 and 12103, respectively, located on the rearview mirrors. Imaging range 12114 represents the imaging range of imaging unit 12104, located on the rear bumper or rear door. For example, by superimposing the image data captured by imaging units 12101 through 12104, a bird's-eye view image of vehicle 12100, viewed from above, can be obtained.

[0144] At least one of the imaging units 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0145] For example, based on the distance information obtained from imaging units 12101 to 12104, microcomputer 12051 can determine the distance to each three-dimensional object within imaging ranges 12111 to 12114 and the temporal change in that distance (relative speed with respect to vehicle 12100). It can then identify the closest three-dimensional object as the preceding vehicle. Specifically, this closest three-dimensional object is located on the travel path of vehicle 12100 and is traveling in the same direction as vehicle 12100 at a predetermined speed (e.g., equal to or greater than 0 km / h). Furthermore, microcomputer 12051 can pre-set the distance to be maintained between the vehicle and the preceding vehicle and execute automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), and other related control mechanisms. Consequently, it is possible to implement cooperative control, such as automated driving, designed to enable the vehicle to travel autonomously without relying on driver input.

[0146] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can classify 3D object data of 3D objects into 3D object data of two-wheeled vehicles, standard vehicles, large vehicles, pedestrians, utility poles, and other 3D objects, extract the classified 3D object data, and use the extracted 3D object data to automatically avoid obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as those that the driver of the vehicle 12100 can visually identify and those that are difficult for the driver of the vehicle 12100 to visually identify. The microcomputer 12051 then determines a collision risk indicating the risk of collision with each obstacle. If the collision risk is equal to or greater than a set value, indicating a collision possibility, the microcomputer 12051 outputs a warning to the driver via the audio speaker 12061 or the display unit 12062, and executes forced deceleration or evasive steering via the drive system control unit 12010. Thus, the microcomputer 12051 can assist in driving to avoid collisions.

[0147] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. The microcomputer 12051 can identify pedestrians, for example, by determining whether a pedestrian exists in the images captured by the imaging units 12101 to 12104. For example, this pedestrian identification is performed by extracting feature points from the images captured by the imaging units 12101 to 12104, which are infrared cameras, and performing pattern matching on a series of feature points representing the outline of an object to determine whether the object is a pedestrian. If the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and identifies the pedestrian, the audio / video output unit 12052 controls the display unit 12062 to display a square outline superimposed on the identified pedestrian for emphasis. The audio / video output unit 12052 can also control the display unit 12062 to display an icon representing the pedestrian at a desired location.

[0148] 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 camera unit 12031 in the above-described configuration. Applying the technology according to the present disclosure to the camera unit 12031 makes it possible to realize the camera unit 12031 capable of improving the ranging range. <7. Application Examples of Endoscopic Surgery Systems>

[0149] The technology according to the present disclosure (the present technology) is applicable to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0150] Figure 27: is a diagram showing a schematic configuration example of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (the present technology) can be applied.

[0151] exist Figure 27 , a surgeon (doctor) 11131 is shown performing surgery on a patient 11132 on a bed 11133 using an endoscopic surgery system 11000. As shown, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 for carrying various devices used for endoscopic surgery.

[0152] Endoscope 11100 includes a lens barrel 11101 and a camera 11102 connected to the proximal end of lens barrel 11101. Lens barrel 11101 is inserted into a body cavity of a patient 11132 at a predetermined length from its distal end. In the illustrated example, endoscope 11100 is shown as a rigid endoscope having a rigid lens barrel 11101. However, endoscope 11100 may also include a flexible endoscope having a flexible lens barrel 11101.

[0153] The lens barrel 11101 has an opening at its distal end for mounting an objective lens. A light source device 11203 is connected to the endoscope 11100 so that light generated by the light source device 11203 is guided to the distal end of the lens barrel 11101 via a light guide extending within the lens barrel 11101 and illuminates an observation target in the body cavity of the patient 11132 through the objective lens. It should be noted that the endoscope 11100 can be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0154] The camera head 11102 is equipped with an optical system and an imaging element. The optical system focuses reflected light (observation light) from the observation target onto the imaging element. The imaging element photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. This image signal is transmitted as RAW data to the camera control unit (CCU) 11201.

[0155] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), and the like, and integrally controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera 11102 and performs various image processing, such as development processing (demosaicing processing), on the image signal for displaying an image based on the image signal.

[0156] The display device 11202 displays an image based on an image signal that has been image-processed by the CCU 11201 under the control of the CCU 11201 .

[0157] The light source device 11203 includes a light source such as a light emitting diode (LED), for example, and supplies irradiation light to the endoscope 11100 when imaging a surgical site or the like.

[0158] The input device 11204 is an input interface for the endoscopic surgery system 11000. The user can input various types of information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user may input instructions to change the imaging conditions of the endoscope 11100 (such as the type of irradiation light, magnification, or focal length).

[0159] The treatment tool control device 11205 controls the driving of the energy device 11112 for cauterizing or incising tissue, sealing blood vessels, and the like. The pneumoperitoneum device 11206 delivers gas into the body cavity of the patient 11132 via the pneumoperitoneum tube 11111 to insulate the cavity, thereby ensuring the field of view of the endoscope 11100 and the surgeon's working space. 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 graphics.

[0160] It should be noted that the light source device 11203 that supplies illumination light to the endoscope 11100 for imaging the surgical site can include, for example, a white light source comprising an LED, a laser light source, or a combination thereof. If the white light source comprises a combination of red, green, and blue (RGB) laser light sources, the light source device 11203 can perform white balance adjustment for the captured image because the output intensity and output timing of each color (wavelength) can be controlled with high precision. Furthermore, in this case, if the laser beams from each of the RGB laser light sources are irradiated onto the observation target in a time-division manner and the drive of the imaging element of the camera 11102 is controlled in synchronization with the illumination timing, images corresponding to each of the R, G, and B colors can also be captured in a time-division manner. This method enables color images to be obtained even without providing a color filter for the imaging element.

[0161] Furthermore, the light source device 11203 can be controlled so that the intensity of the light output changes at predetermined intervals. By controlling the driving of the imaging element of the camera 11102 in synchronization with the timing of the light intensity change to acquire images in a time-division manner and synthesizing the images, a high dynamic range image can be produced that is free of underexposed shadows and overexposed highlights.

[0162] Furthermore, the light source device 11203 can be configured to supply light of a predetermined wavelength band that can be used for special light observation. In special light observation, for example, narrowband light observation (narrowband imaging) is performed by exploiting the wavelength dependence of light absorption in body tissue to illuminate a narrower band of light than that used for standard observation (i.e., white light). This allows for high-contrast imaging of predetermined tissue, such as blood vessels in the mucosal surface layer. Alternatively, special light observation can be performed by fluorescence observation, which obtains images based on fluorescence generated by irradiating excitation light. Fluorescence observation can be performed by irradiating body tissue with excitation light to observe fluorescence from the tissue (autofluorescence observation), or by locally injecting an agent, such as indocyanine green (ICG), into the tissue and irradiating the tissue with excitation light corresponding to the fluorescence wavelength of the agent to obtain a fluorescence image. The light source device 11203 can be configured to supply narrowband light and / or excitation light suitable for such special light observation.

[0163] Figure 28 It shows Figure 27 A block diagram of an example of the functional configuration of the camera 11102 and CCU 11201 is shown.

[0164] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 for communication.

[0165] The lens unit 11401 is an optical system provided at a connection position with the lens barrel 11101. Observation light taken from the distal end of the lens barrel 11101 is guided to the camera 11102 and introduced into the lens unit 11401. The lens unit 11401 includes a combination of multiple lenses including a zoom lens and a focus lens.

[0166] The number of imaging elements included in the imaging unit 11402 can be one (single-board type) or multiple (multi-board type). For example, when the imaging unit 11402 is configured as a multi-board type imaging unit, image signals corresponding to each of R, G, and B are generated by the imaging elements, and the image signals can be synthesized to obtain a color image. The imaging unit 11402 can also be configured to have a pair of imaging elements for respectively acquiring image signals for the right eye and the left eye for three-dimensional (3D) display. If 3D display is performed, the surgeon 11131 can more accurately understand the depth of living tissue in the surgical site. It should be noted that when the imaging unit 11402 is configured as a stereoscopic type imaging unit, multiple systems of lens units 11401 are provided corresponding to the respective imaging elements.

[0167] In addition, the imaging unit 11402 does not have to be provided on the camera head 11102. For example, the imaging unit 11402 can be provided inside the lens barrel 11101 just behind the objective lens.

[0168] The driving unit 11403 includes an actuator and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera control unit 11405. Therefore, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0169] The communication unit 11404 includes a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits an image signal acquired from the imaging unit 11402 to the CCU 11201 through the transmission cable 11400 as RAW data.

[0170] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and supplies the control signal to the camera control unit 11405. The control signal includes, for example, information related to imaging conditions, such as information specifying a frame rate for capturing an image, information specifying an exposure value when capturing an image, and / or information specifying a magnification and focus of a captured image.

[0171] It should be noted that imaging conditions such as the frame rate, exposure value, magnification, or focus may be specified by the user or may be automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, an automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are incorporated into the endoscope 11100.

[0172] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal received from the CCU 11201 through the communication unit 11404 .

[0173] The communication unit 11411 includes a communication device for transmitting and receiving various types of information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 through the transmission cable 11400.

[0174] In addition, the communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted through electrical communication, optical communication, or the like.

[0175] The image processing unit 11412 performs various image processing on the image signal in the form of RAW data transmitted from the camera 11102 .

[0176] The control unit 11413 performs various types of control related to imaging of the surgical site, etc. by the endoscope 11100 and display of captured images 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 .

[0177] Furthermore, control unit 11413 controls display device 11202 to display a captured image of the surgical site, etc., based on the image signal processed by image processing unit 11412. Therefore, control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, control unit 11413 can detect the shape and color of the edges of objects included in the captured image to identify surgical tools such as forceps, specific living body parts, bleeding, mist generated by the use of energy device 11112, and the like. When control unit 11413 controls display device 11202 to display the captured image, control unit 11413 can use the recognition results to display various types of surgical support information superimposed on the image of the surgical site. Displaying this superimposed surgical support information and presenting it to surgeon 11131 can reduce the burden on surgeon 11131, allowing surgeon 11131 to confidently perform surgery.

[0178] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 to each other is an electric signal cable capable of being used for electric signal communication, an optical fiber capable of being used for optical communication, or a composite cable capable of being used for electric and optical communication.

[0179] Here, although communication is performed by wired communication using the transmission cable 11400 in the illustrated example, communication between the camera 11102 and the CCU 11201 may be performed by wireless communication.

[0180] An example of an endoscopic surgical system to which the technology of the present disclosure can be applied has been described above. For example, the technology of the present disclosure can be applied to the imaging unit 11402 in the above-described configuration. Applying the technology of the present disclosure to the imaging unit 11402 enables the implementation of an imaging unit 11402 capable of improving the ranging range.

[0181] Note that, although an endoscopic surgical system has been described here as an example, the technology according to the present disclosure can be applied to, for example, a microscope surgical system or the like. <11. Other Implementation Options>

[0182] The present technology is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present technology. For example, the photodetectors according to two or more embodiments among the photodetectors according to the first to eighth embodiments may be combined.

[0183] A photodetector according to a first mode of the present disclosure includes a first photoelectric conversion element and a second photoelectric conversion element. The first photoelectric conversion element is provided on the light incident side of the first substrate and converts incident light into electric charge. The second photoelectric conversion element is provided in the first substrate to overlap with the first photoelectric conversion element and includes a multiplication region that multiplies carriers generated by light. In this photodetector, visible light is photoelectrically converted by the first photoelectric conversion element, and infrared light is photoelectrically converted by the second photoelectric conversion element. This allows both visible light information and distance measurement information to be acquired. Consequently, the photodetector can achieve a wide and improved distance measurement range.

[0184] The photodetector according to the second embodiment of the present disclosure further includes a light-shielding member in the photodetector according to the first embodiment. The light-shielding member is provided along the periphery of the second photoelectric conversion element when viewed from the light incident side, penetrates at least the first substrate in the thickness direction, and blocks carriers generated by the second photoelectric conversion element. According to the photodetector structured in this manner, carriers generated from the second photoelectric conversion element can be shielded by the light-shielding body, thereby effectively suppressing or preventing the leakage of carriers to the adjacent second photoelectric conversion element.

[0185] According to the third mode of the present disclosure, the photodetector includes: a first substrate, which includes a first semiconductor substrate and a first insulating layer stacked on the first semiconductor substrate; a second photoelectric conversion element, which is arranged in the first substrate and includes a multiplication region for multiplying carriers generated by light; and a light-shielding body, which is arranged along the periphery of the second photoelectric conversion element when observed from the light incident side, passes through at least the first semiconductor substrate in the thickness direction, and blocks the carriers generated by the second photoelectric conversion element. According to the photodetector structured in this manner, carriers generated from the second photoelectric conversion element can be shielded by the light-shielding body, thereby effectively suppressing or preventing the leakage of carriers to the adjacent second photoelectric conversion element. <Structure of this technology>

[0186] The present technology has the following configuration: According to the present technology having the following configuration, the photodetector can improve the distance measurement range. (1) A light detector comprising: a first photoelectric conversion element that is provided on the light incident side of the first substrate and converts incident light into electric charges; and A second photoelectric conversion element is provided in the first substrate so as to overlap with the first photoelectric conversion element and includes a multiplication region that multiplies carriers generated by photons. (2) The photodetector according to (1), wherein the first photoelectric conversion element is stacked on the second photoelectric conversion element in a light incident direction. (3) The photodetector according to (1) or (2) further includes a second substrate on a side of the first substrate opposite to the first photoelectric conversion element, wherein the second substrate is provided with one or more circuits, the one or more circuits being selected from a drive circuit for driving the first photoelectric conversion element and a read circuit for reading the charge converted by the first photoelectric conversion element. (4) The photodetector according to (3), further including a through-wiring that electrically connects the first photoelectric conversion element and the circuit to each other and passes through the first substrate in a thickness direction. (5) The photodetector according to (4), wherein The first base includes: a first semiconductor substrate on which the second photoelectric conversion element is provided; and a first insulating layer provided on a side of the first semiconductor substrate closer to the second base, and The photodetector further includes a light-blocking body provided along the periphery of the second photoelectric conversion element when viewed from the light incident side, the light-blocking body passing through at least the first semiconductor substrate in a thickness direction and blocking carriers generated by the second photoelectric conversion element. (6) The photodetector according to (5), wherein The through wiring is provided around the second photoelectric conversion element when viewed from the light incident side, and The light-blocking body is provided between the second photoelectric conversion element and the through-wiring. (7) The photodetector according to (5) or (6), wherein the light-shielding body extends into the first insulating layer. (8) The photodetector according to (5) or (6), wherein The second base includes: a second semiconductor substrate in which the circuit is provided; and a second insulating layer provided on a side of the second semiconductor substrate opposite to the first base, and The light shielding body extends into the second semiconductor substrate. (9) The photodetector according to (5) or (6), wherein The second base includes: a second semiconductor substrate in which the circuit is provided; and a second insulating layer provided on a side of the second semiconductor substrate opposite to the first base, and The light-shielding body extends to pass through the second semiconductor substrate in a thickness direction. (10) The photodetector according to (4), wherein the plurality of through wirings are arranged along the periphery of the second photoelectric conversion element when viewed from the light incident side, and are formed as a light shielding body that blocks carriers generated from the second photoelectric conversion element. (11) The photodetector according to (10), wherein one of the through wirings and the other of the through wirings adjacent to each other in an arrangement direction are arranged so that their respective portions overlap each other when viewed from the second photoelectric conversion element. (12) The photodetector according to (5) further includes a first insulator between the through wiring and the light shielding body, wherein the first insulator has a higher dielectric strength voltage than the first insulating layer. (13) The photodetector according to (5) further includes a second insulator between the through wiring and the light-shielding body, the second insulator having a lower dielectric constant than the first insulating layer. (14) The photodetector according to any one of (1) to (13), wherein The first photoelectric conversion element includes an organic photoelectric conversion layer, and The second photoelectric conversion element includes an avalanche diode. (15) The photodetector according to (4), wherein The second photoelectric conversion element includes an avalanche diode including an anode electrode and a cathode electrode, and The photodetector further includes a shield to which a fixed potential is supplied, the shield surrounding the cathode electrode. (16) The photodetector according to any one of (1) to (15), wherein The first photoelectric conversion element converts visible light into electric charges, and The second photoelectric conversion element generates carriers based on infrared light. (17) A light detector comprising: A first substrate comprising a first semiconductor substrate and a first insulating layer stacked on the first semiconductor substrate; a second photoelectric conversion element provided in the first substrate and including a multiplication region that multiplies carriers generated by photons; and A light-blocking body is provided along the periphery of the second photoelectric conversion element when viewed from the light incident side, the light-blocking body passes through at least the first semiconductor substrate in a thickness direction and blocks carriers generated by the second photoelectric conversion element. (18) The photodetector according to (17), wherein the light-shielding body extends into the first insulating layer. (19) The light detector according to (17), further comprising: The second substrate is arranged on a side of the first substrate closer to the first insulating layer and includes a second semiconductor substrate and a second insulating layer, wherein the second insulating layer is arranged on a side of the second semiconductor substrate opposite to the first substrate, The light-shielding body extends into the second semiconductor substrate. (20) The light detector according to (17), further comprising: The second substrate is arranged on a side of the first substrate closer to the first insulating layer and includes a second semiconductor substrate and a second insulating layer, wherein the second insulating layer is arranged on a side of the second semiconductor substrate opposite to the first substrate, The light-shielding body extends to pass through the second semiconductor substrate in a thickness direction.

[0187] This application claims priority from Japanese Patent Application No. JP2023-059227 filed with the Japan Patent Office on March 31, 2023, the entire contents of which are incorporated herein by reference.

[0188] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made according to design requirements and other factors as long as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. A light detector comprising: a first photoelectric conversion element that is provided on the light incident side of the first substrate and converts incident light into electric charges; as well as A second photoelectric conversion element is provided in the first substrate so as to overlap with the first photoelectric conversion element and includes a multiplication region that multiplies carriers generated by photons.

2. The light detector according to claim 1, wherein The first photoelectric conversion element is stacked on the second photoelectric conversion element in a light incident direction.

3. The photodetector according to claim 1 further includes a second substrate on a side of the first substrate opposite to the first photoelectric conversion element, and the second substrate is provided with one or more circuits, and the one or more circuits are selected from a driving circuit for driving the first photoelectric conversion element and a reading circuit for reading the charge converted by the first photoelectric conversion element. 4 . The photodetector according to claim 3 , comprising a through-wiring that electrically connects the first photoelectric conversion element and the circuit to each other and passes through the first substrate in a thickness direction.

5. The light detector according to claim 4, wherein The first base includes: a first semiconductor substrate on which the second photoelectric conversion element is provided; and a first insulating layer provided on a side of the first semiconductor substrate closer to the second base, and The photodetector further includes a light-blocking body provided along the periphery of the second photoelectric conversion element when viewed from the light incident side, the light-blocking body passing through at least the first semiconductor substrate in a thickness direction and blocking carriers generated by the second photoelectric conversion element. The light detector according to claim 5 , wherein The through wiring is provided around the second photoelectric conversion element when viewed from the light incident side, and The light-blocking body is provided between the second photoelectric conversion element and the through-wiring.

7. The light detector according to claim 5, wherein The light-shielding body extends into the first insulating layer.

8. The light detector according to claim 5, wherein The second base includes: a second semiconductor substrate in which the circuit is provided; and a second insulating layer provided on a side of the second semiconductor substrate opposite to the first base, and The light shielding body extends into the second semiconductor substrate.

9. The light detector according to claim 5, wherein The second base includes: a second semiconductor substrate in which the circuit is provided; and a second insulating layer provided on a side of the second semiconductor substrate opposite to the first base, and The light-shielding body is extended to pass through the second semiconductor substrate along a thickness direction.

10. The light detector according to claim 4, wherein The plurality of through wirings are arranged along the periphery of the second photoelectric conversion element when viewed from the light incident side, and are formed as a light-shielding body that blocks carriers generated from the second photoelectric conversion element.

11. The light detector according to claim 10, wherein When viewed from the second photoelectric conversion element, one of the through wirings and the other of the through wirings adjacent to each other in the arrangement direction are arranged so that their respective portions overlap with each other. 12 . The photodetector according to claim 5 , further comprising a first insulator between the through wiring and the light-shielding body, wherein the first insulator has a higher dielectric strength voltage than the first insulating layer. 13 . The photodetector according to claim 5 , further comprising a second insulator between the through wiring and the light-shielding body, the second insulator having a lower dielectric constant than the first insulating layer.

14. The light detector according to claim 1, wherein The first photoelectric conversion element includes an organic photoelectric conversion layer, and The second photoelectric conversion element includes an avalanche diode.

15. The light detector according to claim 4, wherein The second photoelectric conversion element includes an avalanche diode including an anode electrode and a cathode electrode, and The photodetector further includes a shield to which a fixed potential is supplied, the shield surrounding the cathode electrode.

16. The light detector according to claim 1, wherein The first photoelectric conversion element converts visible light into electric charges, and The second photoelectric conversion element generates carriers based on infrared light.

17. A light detector comprising: A first substrate comprising a first semiconductor substrate and a first insulating layer stacked on the first semiconductor substrate; a second photoelectric conversion element provided in the first substrate and including a multiplication region for multiplying carriers generated by photons; as well as A light-blocking body is provided along the periphery of the second photoelectric conversion element when viewed from the light incident side, passes through at least the first semiconductor substrate in the thickness direction, and blocks carriers generated by the second photoelectric conversion element.

18. The light detector according to claim 17, wherein The light-shielding body extends into the first insulating layer.

19. The light detector of claim 17, further comprising: The second substrate is arranged on a side of the first substrate closer to the first insulating layer and includes a second semiconductor substrate and a second insulating layer, wherein the second insulating layer is arranged on a side of the second semiconductor substrate opposite to the first substrate, The light shielding body extends into the second semiconductor substrate.

20. The light detector of claim 17, further comprising: The second substrate is arranged on a side of the first substrate closer to the first insulating layer and includes a second semiconductor substrate and a second insulating layer, wherein the second insulating layer is arranged on a side of the second semiconductor substrate opposite to the first substrate, The light-shielding body is extended to pass through the second semiconductor substrate along a thickness direction.

Images