Light detection element and light detection device

Abstract

A light detection element according to an embodiment of the present disclosure comprises a photoelectric conversion layer, a first structure that has a higher refractive index than the surroundings and is disposed above a first region in which carriers generated by photoelectric conversion are accumulated on the light-incidence side of the photoelectric conversion layer, and a second structure that has a higher refractive index than the surroundings and is disposed above a second region in which carriers are not accumulated on the light-incidence side of the photoelectric conversion layer.

Description

Photodetector element and photodetector device

[0001] The present disclosure relates to a photodetector element and a photodetector device including the same.

[0002] For example, Patent Document 1 discloses an imaging element in which a photoelectric conversion section is formed by stacking a first electrode, a photoelectric conversion layer, and a second electrode in this order, and further includes a charge storage electrode that is arranged at a distance from the first electrode and opposite the photoelectric conversion layer via an insulating layer.

[0003] Japanese Patent Application Laid-Open No. 2017-157816

[0004] Incidentally, there is a demand for improved sensitivity in photodetection devices that are also used as imaging devices.

[0005] It is desirable to provide a photodetector element and a photodetector device that allows for improved sensitivity.

[0006] An optical detection element according to one embodiment of the present disclosure includes a photoelectric conversion layer, a first structure having a refractive index higher than the surrounding area and arranged above a first region on the light incident side of the photoelectric conversion layer where carriers generated by photoelectric conversion accumulate, and a second structure having a refractive index higher than the surrounding area and arranged above a second region on the light incident side of the photoelectric conversion layer where carriers do not accumulate.

[0007] An optical detection device according to one embodiment of the present disclosure includes a plurality of pixels, each of which is provided with an imaging element having one or more photoelectric conversion units, and the one or more photoelectric conversion units include the optical detection elements according to one embodiment of the present disclosure.

[0008] In a photodetector element and a photodetector device according to an embodiment of the present disclosure, a first structure and a second structure having different refractive indices are disposed on the light incident side of a photoelectric conversion layer. The first structure has a refractive index higher than the surrounding area and is disposed above a first region capable of accumulating carriers generated by photoelectric conversion. The second structure has a refractive index lower than the surrounding area and is disposed above a second region in which carriers generated by photoelectric conversion are not accumulated. This allows incident light to be guided to a desired region of the photoelectric conversion layer.

[0009] FIG. 1 is a cross-sectional view schematically illustrating an example of a configuration of a main part of a photodetector element according to an embodiment of the present disclosure. FIG. 2 is a plan view schematically illustrating an example of a pixel configuration of the photodetector element shown in FIG. 1. FIG. 3 is a cross-sectional view schematically illustrating an example of a detailed configuration of a photodetector element according to an embodiment of the present disclosure. FIG. 4 is an equivalent circuit diagram of the photodetector element shown in FIG. 3. FIG. 4 is a schematic diagram illustrating an arrangement of transistors constituting a lower electrode and a control unit of the photodetector element shown in FIG. 3. FIG. 6 is a cross-sectional view for explaining a method of manufacturing the photodetector element shown in FIG. 3. FIG. 7 is a cross-sectional view illustrating a process subsequent to FIG. 6. FIG. 8 is a cross-sectional view illustrating a process subsequent to FIG. 7. FIG. 9 is a cross-sectional view illustrating a process subsequent to FIG. 8. FIG. 10 is a cross-sectional view illustrating a process subsequent to FIG. 9. FIG. 11 is a cross-sectional view illustrating a process subsequent to FIG. 10. FIG. 12 is a cross-sectional view illustrating a process subsequent to FIG. 11. FIG. 13 is a timing chart illustrating an example of an operation of the photodetector element shown in FIG. 3. FIG. 14A is a cross-sectional view schematically illustrating an example of a configuration of a photodetector element according to Variation 1 of the present disclosure. FIG. 14B is a schematic diagram illustrating a planar configuration of the photodetector element shown in FIG. 14A . FIG. 15A is a schematic cross-sectional view illustrating an example of a configuration of a photodetector element according to Modification 2 of the present disclosure. FIG. 15B is a schematic cross-sectional view illustrating a planar configuration of the photodetector element shown in FIG. 15A . FIG. 16 is a schematic cross-sectional view illustrating an example of a configuration of a photodetector element according to Modification 3 of the present disclosure. FIG. 17 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 4 of the present disclosure. FIG. 18 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 5 of the present disclosure. FIG. 19 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 6 of the present disclosure. FIG. 20 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 7 of the present disclosure. FIG. 21 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 8 of the present disclosure. FIG. 22 is a schematic cross-sectional view illustrating an example of a configuration of a main part of a photodetector element according to Modification 9 of the present disclosure. Fig. 23A is a schematic cross-sectional view showing an example of a configuration of a main part of a photodetector according to Modification 10 of the present disclosure. Fig. 23B is a schematic plan view showing an example of a pixel configuration of the photodetector shown in Fig. 23A. Fig. 24A is a schematic cross-sectional view showing an example of a configuration of a main part of a photodetector according to Modification 11 of the present disclosure. Fig. 24B is a schematic plan view showing an example of a pixel configuration of the photodetector shown in Fig. 24A.FIG. 25 is a cross-sectional schematic diagram showing an example of the configuration of a main part of a photodetector according to Modification 12 of the present disclosure. FIG. 26 is a cross-sectional schematic diagram showing an example of the configuration of a main part of a photodetector according to Modification 13 of the present disclosure. FIG. 27A is a planar schematic diagram showing an example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27B is a planar schematic diagram showing another example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27C is a planar schematic diagram showing another example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27D is a planar schematic diagram showing another example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27E is a planar schematic diagram showing another example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27F is a planar schematic diagram showing another example of the shapes of high-refractive-index members and low-refractive-index members according to Modification 14 of the present disclosure. FIG. 27G is a planar schematic diagram showing another example of the shapes of the high-refractive-index member and the low-refractive-index member according to Modification 14 of the present disclosure. FIG. 28A is a cross-sectional schematic diagram showing an example of the shapes of the high-refractive-index member and the low-refractive-index member according to Modification 15 of the present disclosure. FIG. 28B is a cross-sectional schematic diagram showing another example of the shapes of the high-refractive-index member and the low-refractive-index member according to Modification 15 of the present disclosure. FIG. 28C is a cross-sectional schematic diagram showing another example of the shapes of the high-refractive-index member and the low-refractive-index member according to Modification 15 of the present disclosure. FIG. 28D is a cross-sectional schematic diagram showing another example of the shapes of the high-refractive-index member and the low-refractive-index member according to Modification 15 of the present disclosure. FIG. 29 is a block diagram showing the overall configuration of a photodetector including the photodetector element shown in FIG. 3 etc. FIG. 30 is a block diagram showing an example of the configuration of an electronic device using the photodetector shown in FIG. 29 . FIG. 31A is a schematic diagram showing an example of the overall configuration of a photodetection system using the photodetector shown in FIG. 29 . FIG. 31B is a diagram showing an example of the circuit configuration of the photodetection system shown in FIG. 31A . FIG. 32 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. Fig. 33 is a block diagram showing an example of the functional configuration of a camera head and a CCU. Fig. 34 is a block diagram showing an example of a schematic configuration of a vehicle control system. Fig. 35 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following description is one specific example of the present disclosure, and the present disclosure is not limited to the following aspects. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of each component shown in each drawing. The order of description is as follows: 1. Embodiment (Example of a photodetector element in which structures with different refractive indices are arranged on the light incident side of a photoelectric conversion layer) 2. Modifications 2-1. Modification 1 (Another example of the configuration of a photodetector element) 2-2. Modification 2 (Another example of the configuration of a photodetector element) 2-3. Modification 3 (Another example of the configuration of a photodetector element) 2-4. Modification 4 (Another example of the configuration of a photodetector element) 2-5. Modification 5 (Another example of the configuration of a photodetector element) 2-6. Modification 6 (Another example of the configuration of a photodetector element) 2-7. Modification 7 (Another example of the configuration of a photodetector element) 2-8. Modification 8 (Another example of the configuration of a photodetector element) 2-9. 2. Modification 9 (another example of the configuration of the photodetector element) 2-10. Modification 10 (another example of the configuration of the photodetector element) 2-11. Modification 11 (another example of the configuration of the photodetector element) 2-12. Modification 12 (another example of the configuration of the photodetector element) 2-13. Modification 13 (another example of the configuration of the photodetector element) 2-14. Modification 14 (another example of the shapes of the high refractive index member and the low refractive index member) 2-15. Modification 15 (another example of the shapes of the high refractive index member and the low refractive index member) 3. Application examples 4. Application examples

[0011] 1. Embodiment FIG. 1 is a schematic diagram illustrating an example of a cross-sectional configuration of a main portion of a photodetector element (photodetector element 1) according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example of a pixel configuration of a photodetector device 100 including the photodetector element 1 illustrated in FIG. 1, where FIG. 1 illustrates a cross section corresponding to line II-I in FIG. 2. FIG. 3 is a schematic diagram illustrating an example of a detailed cross-sectional configuration of the photodetector element 1 corresponding to line II-II in FIG. 2. The photodetector element 1 constitutes one pixel (unit pixel P) repeatedly arranged in an array in a pixel section 100A of a photodetector device (e.g., photodetector device 100, see FIG. 29 ) such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and video cameras. In the pixel section 100A, as illustrated in FIG. 2, a pixel unit 1a, which is composed of four unit pixels P arranged in, for example, two rows and two columns, serves as a repeating unit and is repeatedly arranged in an array consisting of row and column directions.

[0012] The photodetector element 1 of this embodiment includes a photoelectric conversion unit 10 having a photoelectric conversion layer 14. In this embodiment, on the light incident side S1 of the photoelectric conversion unit 10, a high refractive index member 53 having a refractive index higher than the surrounding area is arranged above an effective area X1 where carriers generated by photoelectric conversion can be accumulated, and a low refractive index member 54 having a refractive index lower than the surrounding area is arranged above an ineffective area X2 where carriers are not accumulated.

[0013] Here, the photoelectric conversion layer 14 corresponds to a specific example of a "photoelectric conversion layer" according to one embodiment of the present disclosure. The effective region X1 corresponds to a specific example of a "first region" according to one embodiment of the present disclosure, and the ineffective region X2 corresponds to a specific example of a "second region" according to one embodiment of the present disclosure. The high refractive index member 53 corresponds to a specific example of a "first structure" according to one embodiment of the present disclosure, and the low refractive index member 54 corresponds to a specific example of a "second structure" according to one embodiment of the present disclosure.

[0014] [Configuration of Photodetector] The photodetector 1 is a so-called vertical spectroscopic photodetector in which, for example, one photoelectric conversion unit 10 and two photoelectric conversion regions 32B, 32R are stacked vertically. The photoelectric conversion unit 10 is provided on the back surface (first surface 30A) of the semiconductor substrate 30. The photoelectric conversion regions 32B, 32R are embedded in the semiconductor substrate 30 and stacked in the thickness direction of the semiconductor substrate 30.

[0015] The photoelectric conversion unit 10 and the photoelectric conversion regions 32B and 32R selectively detect light in different wavelength ranges and perform photoelectric conversion. For example, the photoelectric conversion unit 10 acquires a green (G) color signal. The photoelectric conversion regions 32B and 32R acquire blue (B) and red (R) color signals, respectively, due to differences in absorption coefficients. This allows the photodetector 1 to acquire multiple types of color signals in one pixel without using color filters.

[0016] In this embodiment, a case where electrons, among pairs of electrons and holes (excitons) generated by photoelectric conversion, are read out as signal charges (when an n-type semiconductor region is used as the photoelectric conversion layer) will be described. In addition, in the figures, a "+ (plus)" attached to "p" and "n" indicates that the p-type or n-type impurity concentration is high.

[0017] The semiconductor substrate 30 is, for example, an n-type silicon (Si) substrate and has a p-well 31 in a predetermined region. The surface (second surface 30B) of the semiconductor substrate 30 is provided with, for example, floating diffusions FD1 (region 36B within the semiconductor substrate 30), FD2 (region 37C within the semiconductor substrate 30), and FD3 (region 38C within the semiconductor substrate 30), transfer transistors Tr2 and Tr3, an amplifier transistor (modulation element) AMP, a reset transistor RST, and a select transistor SEL. The second surface 30B of the semiconductor substrate 30 is further provided with a multilayer wiring layer 40 via a gate insulating layer 33. The multilayer wiring layer 40 has, for example, a configuration in which wiring layers 41, 42, and 43 are stacked within an insulating layer 44. A vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, an input / output terminal 116, etc., which will be described later, are provided around the periphery of the semiconductor substrate 30, i.e., around the pixel section 100A.

[0018] Between the rear surface (first surface 30A) of the semiconductor substrate 30 and the photoelectric conversion unit 10, for example, a layer that holds a fixed charge (fixed charge layer 21), a dielectric layer 22 having insulating properties, and an interlayer insulating layer 23 are stacked in this order from the first surface 30A side of the semiconductor substrate 30. Between the first surface 30A and the second surface 30B of the semiconductor substrate 30, a through electrode 34 is provided.

[0019] An optical member such as an on-chip lens 52 is disposed above the photoelectric conversion unit 10 with a protective layer 51 in between. Within the protective layer 51, for example, a high refractive index member 53 and a low refractive index member 54, and wiring 16 that electrically connects the upper electrode 15 and the peripheral circuit unit around the pixel unit 100A are provided.

[0020] In the drawings, the first surface 30A side of the semiconductor substrate 30 is represented as a light incident side S1, and the second surface 30B side is represented as a wiring layer side S2.

[0021] In the photodetector element 1, light incident on the photoelectric conversion unit 10 from the light incident side S1 is absorbed by the photoelectric conversion layer 14. The excitons thus generated move to the interface between the electron donors and electron acceptors that make up the photoelectric conversion layer 14, where they undergo exciton dissociation, i.e., dissociation into electrons and holes. The carriers (electrons and holes) generated here are transported to different electrodes by diffusion due to differences in carrier concentration and an internal electric field due to the difference in work function between the anode (e.g., upper electrode 15) and the cathode (e.g., lower electrode 11), and are detected as photocurrent. The transport direction of the electrons and holes can also be controlled by applying a potential between the lower electrode 11 and the upper electrode 15.

[0022] The structure and materials of each part will be described in detail below.

[0023] The photoelectric conversion unit 10 is an organic photoelectric conversion element that absorbs, for example, green light corresponding to part or all of a selective wavelength range (e.g., 450 nm or more and 650 nm or less) and generates excitons. The photoelectric conversion unit 10 includes a lower electrode 11, an insulating layer 12, an oxide semiconductor layer 13, a photoelectric conversion layer 14, and an upper electrode 15 stacked in this order from the semiconductor substrate 30 side. The photoelectric conversion layer 14 is composed of, for example, a p-type semiconductor and an n-type semiconductor, and has a bulk heterojunction structure within the layer. The bulk heterojunction structure is a p / n junction surface formed by mixing a p-type semiconductor and an n-type semiconductor.

[0024] The lower electrode 11 has, for example, a charge readout electrode 11A and a charge storage electrode 11B arranged in parallel on the interlayer insulating layer 23 .

[0025] The charge readout electrode 11A is for transferring signal charges (e.g., electrons) among carriers generated in the photoelectric conversion layer 14 to the floating diffusion FD1. As shown in FIG. 2 , for example, one charge readout electrode 11A is provided for each pixel unit 1a, which is made up of four unit pixels P arranged in two rows and two columns. The charge readout electrode 11A is connected to the floating diffusion FD1 via, for example, an upper second contact 27A, a pad portion 26A, an upper first contact 25, a pad portion 24, a through electrode 34, a connection portion 41A, and a lower second contact 46.

[0026] The charge storage electrode 11B stores signal charges (e.g., electrons) among the carriers generated in the photoelectric conversion layer 14, and is provided for each unit pixel P. The charge storage electrode 11B is provided for each unit pixel P in an area directly facing the light-receiving surfaces of the photoelectric conversion regions 32B, 32R formed in the semiconductor substrate 30 and covering these light-receiving surfaces. The charge storage electrode 11B is preferably larger than the charge readout electrode 11A, allowing a larger number of carriers to be stored. As shown in FIG. 5 , the voltage application unit 17 is connected to the charge storage electrode 11B via wiring such as an upper third contact 27B and a pad portion 26B.

[0027] The lower electrode 11 further includes a shield electrode 11C. The shield electrode 11C is intended to prevent capacitive coupling between adjacent pixel units 1a. The shield electrode 11C is provided, for example, between adjacent pixel units 1a, and a fixed potential is applied to the shield electrode 11C. The shield electrode 11C further extends between adjacent pixels in the row direction (Y-axis direction) and column direction (X-axis direction) of four unit pixels P arranged in two rows and two columns that make up the pixel unit 1a, as shown in FIG. 2 .

[0028] The lower electrode 11 is made of, for example, a conductive film having optical transparency. The lower electrode 11 preferably has a work function of, for example, 4.0 eV or more and 5.5 eV or less. The constituent material of such a lower electrode 11 is, for example, InP doped with tin (Sn) as a dopant. ２ O ３Indium tin oxide (ITO) is an example of the material. The ITO film may have high or low crystallinity (close to amorphous). In addition to the above, the material for the lower electrode 11 may also be tin oxide (SnO ２ )-based materials, for example, ATO with antimony (Sb) added as a dopant, and FTO with fluorine (F) added as a dopant can be used. Zinc oxide (ZnO) or a zinc oxide-based material with a dopant added can also be used. ZnO-based materials, for example, include aluminum zinc oxide (AZO) with aluminum (Al) added as a dopant, gallium zinc oxide (GZO) with gallium (Ga) added, boron zinc oxide with boron (B) added, and indium zinc oxide (IZO) with indium (In) added. Furthermore, zinc oxide with indium and gallium added as dopants (IGZO, In-GaZnO ４ The lower electrode 11 may be made of CuI, InSbO ４ , ZnMgO, CuInO ２ , MgIN ２ O ４ , CdO, ZnSnO ３ or TiO ２ Alternatively, spinel oxides or YbFe ２ O ４ Oxides having such a structure may also be used.

[0029] When the lower electrode 11 does not need to be optically transparent (for example, when light is incident from the upper electrode 15 side and the photoelectric conversion regions 32R and 32B are not provided below the charge storage electrode 11B), a single metal or alloy having a small work function (for example, φ=3.5 eV to 4.5 eV) can be used. Specific examples include alkali metals (e.g., lithium (Li), sodium (Na), and potassium (K)) and their fluorides or oxides, and alkaline earth metals (e.g., magnesium (Mg) and calcium (Ca)) and their fluorides or oxides. Other examples include rare earth metals such as aluminum (Al), Al—Si—Cu alloys, zinc (Zn), tin (Sn), thallium (Tl), Na—K alloys, Al—Li alloys, Mg—Ag alloys, In, and ytterbium (Yb), or alloys thereof.

[0030] Examples of materials that can be used to form the lower electrode 11 include metals such as platinum (Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum (Al), silver (Ag), tantalum (Ta), tungsten (W), copper (Cu), titanium (Ti), indium (In), tin (Sn), iron (Fe), cobalt (Co), and molybdenum (Mo), alloys containing these metal elements, conductive particles made of these metals, conductive particles of alloys containing these metals, polysilicon containing impurities, carbon-based materials, oxide semiconductors, carbon nanotubes, and graphene. Other examples of materials that can be used to form the lower electrode 11 include organic materials (conductive polymers) such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT / PSS). Alternatively, the above materials can be mixed with a binder (polymer) to form a paste or ink, which can then be cured and used as an electrode.

[0031] The lower electrode 11 can be formed as a single layer or a laminated film made of the above materials. The film thickness of the lower electrode 11 in the lamination direction (hereinafter simply referred to as thickness) is, for example, 20 nm to 200 nm, and preferably 30 nm to 150 nm.

[0032] The insulating layer 12 serves to electrically separate the charge storage electrode 11B from the oxide semiconductor layer 13. The insulating layer 12 is provided, for example, on the interlayer insulating layer 23 so as to cover the lower electrode 11. An opening 12H is provided in the insulating layer 12 above the charge readout electrode 11A of the lower electrode 11, and the charge readout electrode 11A and the oxide semiconductor layer 13 are electrically connected via this opening 12H. The insulating layer 12 is made of, for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ The insulating layer 12 is made of a single layer film made of one of silicon oxynitride (SiON) and silicon oxynitride (SiON), or a laminated film made of two or more of these materials. The thickness of the insulating layer 12 is, for example, 20 nm to 500 nm.

[0033] The oxide semiconductor layer 13 corresponds to a specific example of an "oxide semiconductor layer" according to an embodiment of the present disclosure. The oxide semiconductor layer 13 is intended to accumulate carriers generated in the photoelectric conversion layer 14. Note that the carriers generated in the photoelectric conversion layer 14 may also be accumulated in the photoelectric conversion layer 14 together with the oxide semiconductor layer 13. The oxide semiconductor layer 13 may be formed using, for example, an oxide semiconductor containing at least one element selected from indium (In), gallium (Ga), zinc (Zn), aluminum (Al), and tin (Sn). In this embodiment, electrons among the carriers generated in the photoelectric conversion layer 14 are used as signal charges. For this reason, the oxide semiconductor layer 13 may be formed using an n-type oxide semiconductor material. Specifically, the oxide semiconductor layer 13 may be formed using IGZO (In-Ga-Zn-O-based oxide semiconductor), gallium oxide (Ga ２ O ３ ), ZTO (Zn—Sn—O-based oxide semiconductor), IZO (In—Zn—O-based oxide semiconductor), ITO, indium gallium aluminum oxide (InGaAlO), and indium gallium silicon oxide (InGaSiO). The thickness of the oxide semiconductor layer 13 is, for example, 10 nm to 300 nm.

[0034] The photoelectric conversion layer 14 converts light energy into electrical energy. The photoelectric conversion layer 14 is composed of, for example, two or more organic materials (p-type semiconductor materials or n-type semiconductor materials) that function as p-type or n-type semiconductors, respectively. The photoelectric conversion layer 14 has a junction surface (p / n junction surface) between a p-type semiconductor material and an n-type semiconductor material within the layer. The p-type semiconductor functions relatively as an electron donor, and the n-type semiconductor functions relatively as an electron acceptor. The photoelectric conversion layer 14 provides a site where excitons generated upon light absorption separate into electrons and holes. Specifically, the excitons separate into electrons and holes at the interface (p / n junction surface) between the electron donor and electron acceptor.

[0035] In addition to the p-type and n-type semiconductor materials, the photoelectric conversion layer 14 may also contain an organic material, a so-called dye material, that photoelectrically converts light in a predetermined wavelength range while transmitting light in other wavelength ranges. When the photoelectric conversion layer 14 is formed using three types of organic materials, i.e., a p-type semiconductor material, an n-type semiconductor material, and a dye material, the p-type and n-type semiconductor materials are preferably materials that are optically transparent in the visible range (e.g., 450 nm to 800 nm). The thickness of the photoelectric conversion layer 14 is, for example, 50 nm to 500 nm.

[0036] Examples of organic materials constituting the photoelectric conversion layer 14 include quinacridone derivatives, naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, and fluoranthene derivatives. The photoelectric conversion layer 14 is formed by combining two or more of the above organic materials. The above organic materials function as p-type or n-type semiconductors depending on the combination.

[0037] There are no particular limitations on the organic material that constitutes the photoelectric conversion layer 14. Examples of organic materials that can be used to constitute the photoelectric conversion layer 14 include polymers of phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, and derivatives thereof. Examples of organic materials constituting the photoelectric conversion layer 14 include metal complex dyes, cyanine dyes, merocyanine dyes, phenylxanthene dyes, triphenylmethane dyes, rhodacyanine dyes, xanthene dyes, macrocyclic azaannulene dyes, azulene dyes, naphthoquinone dyes, anthraquinone dyes, condensed polycyclic aromatic compounds such as pyrene, chain compounds in which aromatic rings or heterocyclic compounds are condensed, quinolines having a squarylium group and a croconite methine group as a bonding chain, benzothiazoles, benzoxazoles, and other nitrogen-containing heterocycles, or cyanine-like dyes bonded by a squarylium group and a croconite methine group. Metal complex dyes include dithiol metal complex dyes, metal phthalocyanine dyes, metal porphyrin dyes, and ruthenium complex dyes. Among these, ruthenium complex dyes are particularly preferred, but are not limited to these. However, the photoelectric conversion layer 14 may be made of quantum dots or the like in addition to the organic material.

[0038] The upper electrode 15 is made of, for example, a light-transmitting conductive film, similar to the lower electrode 11. The upper electrode 15 is made of, for example, InP doped with Sn. ２ O ３ The crystallinity of the ITO film may be high or low (close to amorphous). In addition to the above, the upper electrode 15 may also be made of SnO ２Examples of the ZnO-based material include ATO with Sb added as a dopant and FTO with fluorine added as a dopant. ZnO or a zinc oxide-based material with a dopant added may also be used. Examples of the ZnO-based material include AZO with Al added as a dopant, GZO with Ga added, boron zinc oxide with B added, and IZO with In added. IGZO (In-GaZnO4) may also be used with indium and gallium added as dopants. The constituent materials of the lower electrode 11 include CuI, InSbO ４ , ZnMgO, CuInO ２ , MgIN ２ O ４ , CdO, ZnSnO ３ or TiO ２ Alternatively, spinel oxides or YbFe ２ O ４ Oxides having such a structure may also be used.

[0039] Furthermore, if optical transparency is not required for the upper electrode 15, a single metal or alloy having a large work function (for example, φ=4.5 eV to 5.5 eV) can be used. Specific examples include Au, Ag, Cr, Ni, Pd, Pt, Fe, iridium (Ir), germanium (Ge), osmium (Os), rhenium (Re), tellurium (Te), and alloys thereof.

[0040] Furthermore, examples of materials that can be used to form the upper electrode 15 include metals such as Pt, Au, Pd, Cr, Ni, Al, Ag, Ta, W, Cu, Ti, In, Sn, Fe, Co, and Mo, alloys containing these metal elements, conductive particles made of these metals, conductive particles of alloys containing these metals, polysilicon containing impurities, carbon-based materials, oxide semiconductors, carbon nanotubes, and graphene. Other examples of materials that can be used to form the upper electrode 15 include organic materials (conductive polymers) such as PEDOT / PSS. Furthermore, the above materials can be mixed with a binder (polymer) to form a paste or ink, which can then be cured and used as an electrode.

[0041] The upper electrode 15 can be formed as a single layer or a laminated film made of the above materials. The thickness of the upper electrode 15 is, for example, 20 nm to 200 nm, preferably 30 nm to 150 nm.

[0042] The photoelectric conversion unit 10 may have other layers between the lower electrode 11 and the photoelectric conversion layer 14 and between the photoelectric conversion layer 14 and the upper electrode 15. For example, a hole blocking layer may be provided between the lower electrode 11 and the photoelectric conversion layer 14. The hole blocking layer prevents holes from moving from the lower electrode 11 to the photoelectric conversion layer 14 and efficiently transports electrons, among carriers generated in the photoelectric conversion layer 14, to the lower electrode 11. An electron blocking layer or a work function adjustment layer may be provided between the photoelectric conversion layer 14 and the upper electrode 15. The electron blocking layer prevents electrons from moving from the upper electrode 15 to the photoelectric conversion layer 14 and efficiently transports holes, among carriers generated in the photoelectric conversion layer 14, to the upper electrode 15. The work function adjustment layer has an electron affinity or work function greater than the work function of the upper electrode 15 and improves the electrical connection between the photoelectric conversion layer 14 and the upper electrode 15.

[0043] 1 and 3 show an example in which the insulating layer 12, the oxide semiconductor layer 13, the photoelectric conversion layer 14, and the upper electrode 15 are formed separately for each photodetector element 1, but the oxide semiconductor layer 13, the photoelectric conversion layer 14, and the upper electrode 15 may be formed separately for each unit pixel P, for example.

[0044] The fixed charge layer 21 serves to reduce the interface state with the semiconductor substrate 30 and to suppress the generation of dark current from the interface with the semiconductor substrate 30. The fixed charge layer 21 may be a film having positive fixed charges or a film having negative fixed charges. The fixed charge layer 21 is preferably formed using a semiconductor material or a conductive material having a wider band gap than the semiconductor substrate 30. This makes it possible to suppress the generation of dark current at the interface with the semiconductor substrate 30. The fixed charge layer 21 may be formed using, for example, hafnium oxide (HfO ｘ ), aluminum oxide (AlO ｘ ), zirconium oxide (ZrO ｘ ), tantalum oxide (TaO ｘ ), titanium oxide (TiO ｘ ), lanthanum oxide (LaO ｘ ), praseodymium oxide (PrO ｘ ), cerium oxide (CeO ｘ ), neodymium oxide (NdO ｘ ), promethium oxide (PmO ｘ ), samarium oxide (SmO ｘ ), europium oxide (EuO ｘ ), gadolinium oxide (GdO ｘ ), terbium oxide (TbO ｘ ), dysprosium oxide (DyO ｘ ), holmium oxide (HoO ｘ ), thulium oxide (TmO ｘ ), ytterbium oxide (YbO ｘ ), lutetium oxide (LuO ｘ ), yttrium oxide (YO ｘ ), hafnium nitride (HfN ｘ ), aluminum nitride (AlN ｘ ), hafnium oxynitride (HfO ｘ N ｙ ) and aluminum oxynitride (AlO ｘ N ｙ ) etc.

[0045] The dielectric layer 22 is intended to prevent light reflection caused by the difference in refractive index between the semiconductor substrate 30 and the interlayer insulating layer 23. The dielectric layer 22 is preferably formed using a material having a refractive index between the refractive index of the semiconductor substrate 30 and the refractive index of the interlayer insulating layer 23. Examples of materials that can be used to form the dielectric layer 22 include silicon oxide, TEOS, silicon nitride, and silicon oxynitride (SiON).

[0046] The interlayer insulating layer 23 is configured, for example, as a single layer film made of one of silicon oxide, silicon nitride, silicon oxynitride, etc., or as a laminated film made of two or more of these. The interlayer insulating layer 23 is provided with pad portions 24, 26A, 26B, an upper first contact 25, an upper second contact 27A, an upper third contact 27B, etc.

[0047] The photoelectric conversion regions 32B and 32R are configured by, for example, PIN (Positive Intrinsic Negative) type photodiodes, and each has a pn junction in a predetermined region of the semiconductor substrate 30. The photoelectric conversion regions 32B and 32R are capable of splitting light in the vertical direction by utilizing the fact that the wavelength of light absorbed varies depending on the depth of incidence of the light in the silicon substrate.

[0048] The photoelectric conversion region 32B selectively detects, for example, blue light and accumulates signal charges corresponding to blue, and is located at a depth that allows efficient photoelectric conversion of blue light. The photoelectric conversion region 32R selectively detects, for example, red light and accumulates signal charges corresponding to red, and is located at a depth that allows efficient photoelectric conversion of red light. Note that blue (B) corresponds to, for example, a wavelength range of 400 nm or more and less than 495 nm, and red (R) corresponds to, for example, a wavelength range of 620 nm or more and less than 750 nm. Each of the photoelectric conversion regions 32B and 32R may be capable of detecting light in some or all of the wavelength ranges.

[0049] 3, the photoelectric conversion regions 32B and 32R each have, for example, a p+ region that serves as a hole accumulation layer and an n region that serves as an electron accumulation layer (having a p-n-p stacked structure). The n region of the photoelectric conversion region 32B is connected to the vertical transistor Tr2. The p+ region of the photoelectric conversion region 32B bends along the vertical transistor Tr2 and is connected to the p+ region of the photoelectric conversion region 32R.

[0050] The gate insulating layer 33 is configured, for example, as a single layer film made of one of silicon oxide, silicon nitride, silicon oxynitride, etc., or as a laminated film made of two or more of these materials.

[0051] The through electrode 34 is provided between the first surface 30A and the second surface 30B of the semiconductor substrate 30, and functions as a connector between the photoelectric conversion unit 10 and the gate Gamp of the amplifier transistor AMP and the floating diffusion FD1, and also serves as a transmission path for carriers generated in the photoelectric conversion unit 10. A reset gate Grst of the reset transistor RST is disposed adjacent to the floating diffusion FD1 (one of the source / drain regions 36B of the reset transistor RST). This makes it possible for the reset transistor RST to reset carriers accumulated in the floating diffusion FD1.

[0052] The upper end of the through electrode 34 is connected to the charge readout electrode 11A via, for example, a pad portion 24, an upper first contact 25, a pad portion 26A, and an upper second contact 27A provided in the interlayer insulating layer 23. The lower end of the through electrode 34 is connected to a connection portion 41A in the wiring layer 41, and the connection portion 41A and the gate Gamp of the amplifier transistor AMP are connected via a lower first contact 45. The connection portion 41A and the floating diffusion FD1 (region 36B) are connected via, for example, a lower second contact 46.

[0053] The pad portions 24, 26A, 26B, the upper first contact 25, the upper second contact 27A, the upper third contact 27B, the lower first contact 45, the lower second contact 46, and the wiring 16 can be formed using, for example, a silicon material doped with impurities such as PDAS (Phosphorus Doped Amorphous Silicon), or a metal material such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), and tantalum (Ta).

[0054] The protective layer 51 protects the upper surface of the upper electrode 15 and also flattens the surface on the light incident side S1 of the photoelectric conversion body 10. The protective layer 51 is made of a light-transmitting material, such as silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon oxynitride (SiON) and aluminum oxide (AlO ｘ The protective layer 51 has a thickness of, for example, 100 nm to 30,000 nm.

[0055] As described above, the high refractive index member 53 and the low refractive index member 54 are provided within the protective layer 51 .

[0056] As described above, the lower electrode 11 includes a charge storage electrode 11B for storing signal charges (e.g., electrons) among the carriers generated in the photoelectric conversion layer 14, and a charge readout electrode 11A for transferring the signal charges (e.g., electrons) stored above the charge storage electrode 11B to the floating diffusion FD1. In the photodetector element 1, carriers generated in the photoelectric conversion layer 14 above the charge readout electrode 11A cannot be stored, which is one of the causes of reduced sensitivity. In this embodiment, the region above the charge readout electrode 11A that cannot store carriers generated by photoelectric conversion is referred to as an ineffective region X2, and the region of the pixel unit 100A that can store carriers generated by photoelectric conversion, including the region above the charge storage electrode 11B but excluding the free region X2, is referred to as an effective region X1.

[0057] The high-refractive-index member 53 guides light incident on the on-chip lens 52 to the effective region X1 of the photoelectric conversion layer 14. As shown in Fig. 2, for example, the high-refractive-index member 53 has substantially the same shape as the charge storage electrode 11B and is disposed above the charge storage electrode 11B. The high-refractive-index member 53 is made of a material having a higher refractive index than the protective layer 51 provided around it.

[0058] The low-refractive-index member 54 guides light incident on the on-chip lens 52 to the effective region X1, avoiding the ineffective region X2 of the photoelectric conversion layer 14. The low-refractive-index member 54 is disposed above the charge readout electrode 11A. The low-refractive-index member 54 is made of a material having a lower refractive index than the protective layer 51 provided around it.

[0059] The high refractive index member 53 and the low refractive index member 54 may be made of, for example, titanium oxide (TiO ｘ ), niobium oxide, tantalum oxide (TaO ｘ ), aluminum oxide (AlO ｘ ), hafnium oxide (HfO ｘ ), silicon nitride (SiN ｘ ), silicon oxide (SiO ｘ ), silicon oxynitride (SiON), silicon carbide (SiC), silicon oxide carbide (SiOC), silicon nitride carbide (SiNC), and zirconium oxide (ZrO ｘ The high refractive index member 53 and the low refractive index member 54 are selected from the above materials in consideration of the difference in refractive index from the protective layer 51. The low refractive index member 54 may have a hollow structure, for example.

[0060] The on-chip lens 52 is made of a light-transmitting material, such as silicon oxide, silicon nitride, silicon oxynitride, etc. An anti-reflection film may be provided on the surface of the on-chip lens 52.

[0061] Fig. 4 is an equivalent circuit diagram of the photodetector element 1 shown in Fig. 3. Fig. 5 is a schematic diagram showing the arrangement of the lower electrode 11 and transistors constituting the control section of the photodetector element 1 shown in Fig. 3.

[0062] The reset transistor RST (reset transistor TR1rst) resets carriers transferred from the photoelectric conversion unit 10 to the floating diffusion FD1, and is configured, for example, by a MOS transistor. Specifically, the reset transistor TR1rst is configured by a reset gate Grst, a channel formation region 36A, and source / drain regions 36B and 36C. The reset gate Grst is connected to a reset line RST1, and one source / drain region 36B of the reset transistor TR1rst also serves as the floating diffusion FD1. The other source / drain region 36C constituting the reset transistor TR1rst is connected to a power supply line VDD.

[0063] The amplifier transistor AMP (amplifier transistor TR1amp) is a modulation element that modulates the amount of charge generated in the photoelectric conversion unit 10 into a voltage, and is configured, for example, by a MOS transistor. Specifically, the amplifier transistor AMP is configured with a gate Gamp, a channel formation region 35A, and source / drain regions 35B and 35C. The gate Gamp is connected to the charge readout electrode 11A and one source / drain region 36B (floating diffusion FD1) of the reset transistor TR1rst via a lower first contact 45, a connection portion 41A, a lower second contact 46, a through-electrode 34, etc. Furthermore, one source / drain region 35B shares an area with the other source / drain region 36C that constitutes the reset transistor TR1rst and is connected to the power supply line VDD.

[0064] The select transistor SEL (select transistor TR1sel) is composed of a gate Gsel, a channel formation region 34A, and source / drain regions 34B and 34C. The gate Gsel is connected to a select line SEL1. One source / drain region 34B shares an area with the other source / drain region 35C that constitutes the amplifier transistor AMP, and the other source / drain region 34C is connected to a signal line (data output line) VSL1.

[0065] The transfer transistor TR2 (transfer transistor TR2trs) transfers signal charges corresponding to blue generated and accumulated in the photoelectric conversion region 32B to the floating diffusion FD2. Because the photoelectric conversion region 32B is formed deep below the second surface 30B of the semiconductor substrate 30, the transfer transistor TR2trs in the photoelectric conversion region 32B is preferably configured as a vertical transistor. The transfer transistor TR2trs is connected to a transfer gate line TG2. A floating diffusion FD2 is provided in the region 37C near the gate Gtrs2 of the transfer transistor TR2trs. Carriers accumulated in the photoelectric conversion region 32B are read out to the floating diffusion FD2 via a transfer channel formed along the gate Gtrs2.

[0066] The transfer transistor TR3 (transfer transistor TR3trs) transfers the signal charges corresponding to red that are generated and accumulated in the photoelectric conversion region 32R to the floating diffusion FD3, and is configured, for example, by a MOS transistor. The transfer transistor TR3trs is connected to a transfer gate line TG3. A floating diffusion FD3 is provided in the region 38C near the gate Gtrs3 of the transfer transistor TR3trs. Carriers accumulated in the photoelectric conversion region 32R are read out to the floating diffusion FD3 via a transfer channel formed along the gate Gtrs3.

[0067] Further provided on the second surface 30B side of the semiconductor substrate 30 are a reset transistor TR2rst, an amplifier transistor TR2amp, and a selection transistor TR2sel that constitute a control section of the photoelectric conversion region 32B. Further provided are a reset transistor TR3rst, an amplifier transistor TR3amp, and a selection transistor TR3sel that constitute a control section of the photoelectric conversion region 32R.

[0068] The reset transistor TR2rst is composed of a gate, a channel forming region, and source / drain regions. The gate of the reset transistor TR2rst is connected to a reset line RST2, and one of the source / drain regions of the reset transistor TR2rst is connected to a power supply line VDD. The other source / drain region of the reset transistor TR2rst also serves as a floating diffusion FD2.

[0069] The amplifier transistor TR2amp is composed of a gate, a channel forming region, and source / drain regions. The gate is connected to the other source / drain region (floating diffusion FD2) of the reset transistor TR2rst. One of the source / drain regions constituting the amplifier transistor TR2amp shares the same region with one of the source / drain regions constituting the reset transistor TR2rst and is connected to the power supply line VDD.

[0070] The selection transistor TR2sel is composed of a gate, a channel formation region, and source / drain regions. The gate is connected to a selection line SEL2. One of the source / drain regions constituting the selection transistor TR2sel is shared with the other source / drain region constituting the amplifier transistor TR2amp. The other source / drain region constituting the selection transistor TR2sel is connected to a signal line (data output line) VSL2.

[0071] The reset transistor TR3rst is composed of a gate, a channel forming region, and source / drain regions. The gate of the reset transistor TR3rst is connected to a reset line RST3, and one of the source / drain regions constituting the reset transistor TR3rst is connected to a power supply line VDD. The other source / drain region constituting the reset transistor TR3rst also serves as a floating diffusion FD3.

[0072] The amplifier transistor TR3amp is composed of a gate, a channel forming region, and source / drain regions. The gate is connected to the other source / drain region (floating diffusion FD3) constituting the reset transistor TR3rst. One of the source / drain regions constituting the amplifier transistor TR3amp shares the same region with one of the source / drain regions constituting the reset transistor TR3rst and is connected to the power supply line VDD.

[0073] The selection transistor TR3sel is composed of a gate, a channel formation region, and source / drain regions. The gate is connected to a selection line SEL3. One of the source / drain regions constituting the selection transistor TR3sel shares the same region with the other of the source / drain regions constituting the amplifier transistor TR3amp. The other of the source / drain regions constituting the selection transistor TR3sel is connected to a signal line (data output line) VSL3.

[0074] The reset lines RST1, RST2, and RST3, the selection lines SEL1, SEL2, and SEL3, and the transfer gate lines TG2 and TG3 are connected to vertical drive circuits that constitute the drive circuit, and the signal lines (data output lines) VSL1, VSL2, and VSL3 are connected to a column signal processing circuit 112 that constitutes the drive circuit.

[0075] [Method for Manufacturing Photodetector] The photodetector 1 of this embodiment can be manufactured, for example, as follows.

[0076] 6 to 12 show the process sequence of the manufacturing method of the photodetector element 1. First, as shown in Fig. 6, for example, a p-well 31 is formed in a semiconductor substrate 30, and for example, n-type photoelectric conversion regions 32B and 32R are formed in this p-well 31. A p+ region is formed near the first surface 30A of the semiconductor substrate 30.

[0077] 6, n+ regions that will become floating diffusions FD1 to FD3 are formed on the second surface 30B of the semiconductor substrate 30, followed by the formation of a gate insulating layer 33 and a gate wiring layer 47 including the gates of the transfer transistor Tr2, the transfer transistor Tr3, the select transistor SEL, the amplifier transistor AMP, and the reset transistor RST. This results in the formation of the transfer transistor Tr2, the transfer transistor Tr3, the select transistor SEL, the amplifier transistor AMP, and the reset transistor RST. Furthermore, a multilayer wiring layer 40 is formed on the second surface 30B of the semiconductor substrate 30, which includes wiring layers 41 to 43, each including a lower first contact 45, a lower second contact 46, and a connection portion 41A, and an insulating layer 44.

[0078] The base of the semiconductor substrate 30 is, for example, an SOI (Silicon on Insulator) substrate in which the semiconductor substrate 30, a buried oxide film (not shown), and a support substrate (not shown) are stacked. Although not shown in FIG. 6, the buried oxide film and the support substrate are bonded to the first surface 30A of the semiconductor substrate 30. After the ion implantation, an annealing process is performed.

[0079] Next, a support substrate (not shown) or another semiconductor substrate is bonded to the multilayer wiring layer 40 provided on the second surface 30B side of the semiconductor substrate 30, and the semiconductor substrate 30 is then turned upside down. Subsequently, the semiconductor substrate 30 is separated from the buried oxide film of the SOI substrate and the support substrate, exposing the first surface 30A of the semiconductor substrate 30. The above steps can be performed using techniques used in ordinary CMOS processes, such as ion implantation and CVD (Chemical Vapor Deposition).

[0080] 7, the semiconductor substrate 30 is processed from the first surface 30A side by, for example, dry etching to form, for example, an annular opening 34H. As shown in FIG. 7, the depth of the opening 34H penetrates from the first surface 30A to the second surface 30B of the semiconductor substrate 30 and reaches, for example, the connection portion 41A.

[0081] Next, for example, a negative fixed charge layer 21 and a dielectric layer 22 are formed in this order on the first surface 30A of the semiconductor substrate 30 and the side surface of the opening 34H. The fixed charge layer 21 is formed of, for example, HfO ｘ The dielectric layer 22 can be formed by depositing a SiO film using, for example, a plasma CVD method. ｘ Next, a pad portion 24 is formed at a predetermined position on the dielectric layer 22. The pad portion 24 is made of a barrier metal, for example, a laminated film of titanium and titanium nitride (Ti / TiN film), and a W film. Thereafter, an interlayer insulating layer 23 is formed on the dielectric layer 22 and the pad portion 24, and the surface of the interlayer insulating layer 23 is planarized using a chemical mechanical polishing (CMP) method.

[0082] 8, an opening 23H is formed on the pad portion 24, and then a conductive material such as Al is filled into this opening 23H to form the upper first contact 25. Next, as shown in Fig. 8, pad portions 26A and 26B are formed in the same manner as the pad portion 24, and then the interlayer insulating layer 23 and the upper second contact 27A and upper third contact 27B are formed in this order.

[0083] 9, a conductive film 11X is formed on the interlayer insulating layer 23 by, for example, sputtering, and then patterned by photolithography. Specifically, a photoresist PR is formed at a predetermined position on the conductive film 11X, and then the conductive film 11X is processed by dry etching or wet etching. The photoresist PR is then removed, thereby forming the charge readout electrode 11A and the charge storage electrode 11B, as shown in FIG.

[0084] Next, as shown in FIG. 11 , the insulating layer 12, the oxide semiconductor layer 13, the photoelectric conversion layer 14, and the upper electrode 15 are formed in this order. The insulating layer 12 is formed by depositing a silicon oxide film using, for example, the ALD method, and then planarizing the surface of the insulating layer 12 using the CMP method. Thereafter, an opening 12H is formed on the charge readout electrode 11A using, for example, wet etching. The oxide semiconductor layer 13 can be formed using, for example, the sputtering method. The photoelectric conversion layer 14 is formed using, for example, the vacuum deposition method. The upper electrode 15 is formed, like the lower electrode 11, using, for example, the sputtering method.

[0085] 12, a high-refractive-index member 53 is formed above the charge storage electrode 11B, and a low-refractive-index member 54 is formed above the charge readout electrode 11A. The high-refractive-index member 53 can be formed by depositing a high-refractive-index film using a sputtering method and then patterning it using a photolithography technique. Similarly, the low-refractive-index member 54 can be formed by depositing a low-refractive-index film using a sputtering method and then patterning it using a photolithography technique. Finally, a protective layer 51 is formed to cover the upper electrode 15, the high-refractive-index member 53, and the low-refractive-index member 54, and then an on-chip lens 52 is disposed on the protective layer 51. This completes the photodetector element 1 shown in FIG. 3.

[0086] Conductive films such as the photoelectric conversion layer 14, the lower electrode 11, and the upper electrode 15 can be formed using a dry film formation method or a wet film formation method. Examples of dry film formation methods include vacuum deposition using resistance heating or high-frequency heating, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, RF-DC coupled bias sputtering, ECR sputtering, facing target sputtering, and high-frequency sputtering), ion plating, laser ablation, molecular beam epitaxy, and laser transfer. Other examples of dry film formation methods include chemical vapor deposition methods such as plasma CVD, thermal CVD, MOCVD, and photo-CVD. Examples of wet film formation methods include spin coating, inkjet printing, spray coating, stamping, microcontact printing, flexographic printing, offset printing, gravure printing, and dipping.

[0087] For patterning, in addition to photolithography, chemical etching such as shadow mask and laser transfer, physical etching using ultraviolet light or laser, etc. can be used. As for planarization techniques, in addition to CMP, laser planarization, reflow, etc. can be used.

[0088] [Signal Acquisition Operation of Photodetection Element] In the photodetection element 1, when light is incident on the photoelectric conversion unit 10 via the on-chip lens 52, the light passes through the photoelectric conversion unit 10 and the photoelectric conversion regions 32B and 32R in that order, and is photoelectrically converted into green, blue, and red light during the passage. The signal acquisition operation for each color will be described below.

[0089] (Acquisition of Green Signal by Photoelectric Conversion Unit 10) Of the light incident on the photodetector element 1, green light (G) is first selectively detected (absorbed) by the photoelectric conversion unit 10 and photoelectrically converted.

[0090] The photoelectric conversion unit 10 is connected to the gate Gamp of the amplifier transistor AMP and the floating diffusion FD1 via the through electrode 34. Therefore, electrons of the excitons generated in the photoelectric conversion unit 10 are extracted from the lower electrode 11 side, transferred to the second surface 30B side of the semiconductor substrate 30 via the through electrode 34, and accumulated in the floating diffusion FD1. At the same time, the amount of charge generated in the photoelectric conversion unit 10 is modulated into a voltage by the amplifier transistor AMP.

[0091] In addition, a reset gate Grst of the reset transistor RST is disposed next to the floating diffusion FD1, so that the charge accumulated in the floating diffusion FD1 is reset by the reset transistor RST.

[0092] Since the photoelectric conversion unit 10 is connected not only to the amplifier transistor AMP but also to the floating diffusion FD1 via the through electrode 34, the charge accumulated in the floating diffusion FD1 can be easily reset by the reset transistor RST.

[0093] On the other hand, if the through electrode 34 and the floating diffusion FD1 are not connected, it becomes difficult to reset the charge accumulated in the floating diffusion FD1, and a large voltage must be applied to extract the charge to the upper electrode 15. This may damage the photoelectric conversion layer 14. Furthermore, a structure that allows resetting in a short time increases dark noise, which is a trade-off, making this structure difficult to implement.

[0094] 13 shows an example of operation of the photodetector element 1. (A) shows the potential at the charge storage electrode 11B, (B) shows the potential at the floating diffusion FD1 (charge readout electrode 11A), and (C) shows the potential at the gate (Gsel) of the reset transistor TR1rst. In the photodetector element 1, voltages are applied to the charge readout electrode 11A and the charge storage electrode 11B individually.

[0095] In the photodetector element 1, during the accumulation period, a potential V1 is applied from the drive circuit to the charge readout electrode 11A, and a potential V2 is applied to the charge storage electrode 11B. Here, the potentials V1 and V2 are set to V2 > V1. As a result, the charge (signal charge; electrons) generated by photoelectric conversion are attracted to the charge storage electrode 11B and stored in the region of the oxide semiconductor layer 13 facing the charge storage electrode 11B (accumulation period). Incidentally, the potential of the region of the oxide semiconductor layer 13 facing the charge storage electrode 11B becomes more negative as the photoelectric conversion time passes. Note that holes are sent from the upper electrode 15 to the drive circuit.

[0096] In the photodetector element 1, a reset operation is performed in the latter half of the accumulation period. Specifically, at timing t1, the scanning unit changes the voltage of the reset signal RST from low to high. As a result, in the unit pixel P, the reset transistor TR1rst is turned on, and as a result, the voltage of the floating diffusion FD1 is set to the power supply voltage and the voltage of the floating diffusion FD1 is reset (reset period).

[0097] After the reset operation is completed, the charge is read out. Specifically, at timing t2, the drive circuit applies a potential V3 to the charge readout electrode 11A and a potential V4 to the charge storage electrode 11B. Here, the potentials V3 and V4 are set to V3 > V4. As a result, the charge stored in the region corresponding to the charge storage electrode 11B is read out from the charge readout electrode 11A to the floating diffusion FD1. That is, the charge stored in the oxide semiconductor layer 13 is read out to the control unit (transfer period).

[0098] After the readout operation is completed, the drive circuit again applies a potential V1 to the charge readout electrode 11A and a potential V2 to the charge storage electrode 11B, causing the charges generated by photoelectric conversion to be attracted to the charge storage electrode 11B and stored in the region of the photoelectric conversion layer 14 facing the charge storage electrode 11B (storage period).

[0099] (Acquisition of Blue and Red Signals by Photoelectric Conversion Regions 32B and 32R) Next, of the light transmitted through the photoelectric conversion unit 10, blue light (B) is absorbed and photoelectrically converted in the photoelectric conversion region 32B, and red light (R) is absorbed and photoelectrically converted in the photoelectric conversion region 32R. In the photoelectric conversion region 32B, electrons corresponding to the incident blue light (B) are accumulated in the n-region of the photoelectric conversion region 32B, and the accumulated electrons are transferred to the floating diffusion FD2 by the transfer transistor Tr2. Similarly, in the photoelectric conversion region 32R, electrons corresponding to the incident red light (R) are accumulated in the n-region of the photoelectric conversion region 32R, and the accumulated electrons are transferred to the floating diffusion FD3 by the transfer transistor Tr3.

[0100] [Functions and Effects] In the photodetector element 1 of this embodiment, a high-refractive-index member 53 having a higher refractive index than the surrounding area is disposed above the effective area X1 on the light incident side S1 of the photoelectric conversion unit 10, and a low-refractive-index member 54 having a lower refractive index than the surrounding area is disposed above the ineffective area X2. This allows light incident on the on-chip lens 52 to be efficiently guided to the effective area X1. This is described below.

[0101] Improved image quality is desired in CMOS image sensors and the like used in electronic devices such as digital still cameras and video cameras. Accordingly, an imaging element has been disclosed in which, as described above, a photoelectric conversion unit formed by laminating a first electrode, a photoelectric conversion layer, and a second electrode in this order further includes a charge storage electrode disposed spaced apart from the first electrode and facing the photoelectric conversion layer with an insulating layer interposed therebetween, thereby suppressing the occurrence of phenomena such as increased kTC noise, worsened random noise, and a deterioration in image quality.

[0102] In an image sensor having a charge storage electrode disposed on the first electrode side at a distance from the first electrode as described above, the region of the photoelectric conversion layer above the first electrode used for reading out charges no longer functions as the sensitivity of the image sensor, and light absorption in this region results in loss, causing a decrease in sensitivity.

[0103] In contrast to this, in the present embodiment, as described above, on the light incident side S1 of the photoelectric conversion unit 10, the high-refractive-index member 53 is arranged above the effective region X1, and the low-refractive-index member 54 is arranged above the ineffective region X2. Light is guided toward the side with a higher refractive index. Therefore, light incident on the on-chip lens 52 is efficiently guided to the effective region X1, avoiding the ineffective region X2.

[0104] As described above, in the photodetector element 1 of this embodiment, the optical loss in the ineffective area X2 is reduced, and therefore the sensitivity can be improved.

[0105] Next, modified examples 1 to 15 of the present disclosure will be described. Note that components corresponding to those in the photodetector element 1 of the above embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0106] 2. Modifications (2-1. Modification 1) FIG. 14A is a schematic diagram illustrating a cross-sectional configuration of a photodetector element 2 according to Modification 1 of the present disclosure. FIG. 14B is a schematic diagram illustrating an example of the planar configuration of the photodetector element 2 illustrated in FIG. 14A, and FIG. 14A illustrates a cross section corresponding to line III-III illustrated in FIG. 14B. The photodetector element 2 is, for example, a stacked photodetector element in which a photoelectric conversion region 32 and a photoelectric conversion unit 10 are stacked. In a pixel unit 100A of a photodetector device (e.g., photodetector device 100) including this photodetector element 2, pixel units 1a each consisting of four pixels arranged in two rows and two columns are repeated in an array formed in the row and column directions, as illustrated in FIG. 14B.

[0107] In the photodetector element 2 of this modification, a color filter 55 that selectively transmits red light (R), green light (G), and blue light (B) is provided for each unit pixel P above the photoelectric conversion section 10 (on the light incident side S1). Specifically, in a pixel unit 1a consisting of four pixels arranged in two rows and two columns, two color filters (green filters 55G) that selectively transmit green light (G) are arranged diagonally, and one color filter (red filter 55R and blue filter 55B) that selectively transmit red light (R) and blue light (B) is arranged on each diagonal that is perpendicular to the pixel unit 1a. In the unit pixels (Pr, Pg, Pb) provided with the color filters 55R, 55G, and 55B, the photoelectric conversion section 10 detects light of the corresponding color, for example. That is, in the pixel section 100A, pixels (Pr, Pg, Pb) that detect red light (R), green light (G), and blue light (B) are arranged in a Bayer pattern.

[0108] The photoelectric conversion unit 10 absorbs light corresponding to some or all of the wavelengths in the visible light region of, for example, 400 nm or more and less than 750 nm to generate excitons (electron-hole pairs), and includes a lower electrode 11, an insulating layer 12, an oxide semiconductor layer 13, a photoelectric conversion layer 14, and an upper electrode 15 stacked in this order. As in the above embodiment, the lower electrode 11 has, for example, a charge readout electrode 11A and a charge storage electrode 11B that are independent of each other, and the charge readout electrode 11A is shared by, for example, four pixels. Note that the oxide semiconductor layer 13 may be omitted.

[0109] The photoelectric conversion region 32 detects, for example, an infrared light region of 750 nm or more and 1300 nm or less.

[0110] On the light incident side S1 of the photoelectric conversion unit 10, similarly to the above embodiment, a high refractive index member 53 is disposed above the charge storage electrode 11B, and a low refractive index member 54 is disposed above the charge readout electrode 11A.

[0111] In the photodetector element 2, light in the visible light region (red light (R), green light (G), and blue light (B)) that passes through the color filters 55 is absorbed by the photoelectric conversion units 10 of the unit pixels (Pr, Pg, Pb) in which the color filters 55R, 55G, and 55B are provided, respectively, while other light, for example, light in the infrared light region (e.g., 750 nm or more and 1000 nm or less) (infrared light (IR)), passes through the photoelectric conversion units 10. The infrared light (IR) that passes through the photoelectric conversion units 10 is detected in the photoelectric conversion regions 32 of the unit pixels Pr, Pg, and Pb, and signal charges corresponding to the infrared light (IR) are generated. In other words, a photodetector device 100 including the photodetector element 2 is capable of simultaneously generating both visible light images and infrared light images.

[0112] Furthermore, the photodetector device 100 including the photodetector element 2 can acquire a visible light image and an infrared light image at the same position in the XZ in-plane direction, thereby realizing high integration in the XZ in-plane direction.

[0113] (2-2. Modification 2) FIG. 15A is a schematic diagram illustrating a cross-sectional configuration of a photodetector element 3 according to Modification 2 of the present disclosure. FIG. 15B is a schematic diagram illustrating an example of the planar configuration of the photodetector element 3 illustrated in FIG. 15A, and FIG. 15A illustrates a cross section corresponding to the line IV-IV illustrated in FIG. 15B. In Modification 1 described above, the color filter 55 is provided above the photoelectric conversion unit 10 (on the light incident side S1). However, the color filter 55 may be provided, for example, between the photoelectric conversion region 32 and the photoelectric conversion unit 10, as illustrated in FIG. 15A. Except for this point, the photodetector element 3 has substantially the same configuration as the photodetector element 2 according to Modification 1 described above.

[0114] In the photodetector element 3, for example, the color filter 55 has a configuration in which a color filter (red filter 55R) that selectively transmits at least red light (R) and a color filter (blue filter 55B) that selectively transmits at least blue light (B) are arranged diagonally to each other within the pixel unit 1a. The photoelectric conversion layer 14 of the photoelectric conversion unit 10 is configured to selectively absorb light having a wavelength corresponding to green light (G), for example. The photoelectric conversion region 32R selectively absorbs light having a wavelength corresponding to red light (R), and the photoelectric conversion region 32B selectively absorbs light having a wavelength corresponding to blue light (B). This makes it possible to obtain signals corresponding to red light (R), green light (G), or blue light (B) in the photoelectric conversion regions 32 (photoelectric conversion regions 32R and 32B) arranged below the photoelectric conversion unit 10 and the color filters 55R and 55B, respectively. In the photodetector element 3 of this modified example, the area of ​​the photoelectric conversion portion for each of RGB can be enlarged compared to a photodetector element having a general Bayer array, and therefore the S / N ratio can be improved.

[0115] 16 is a schematic diagram illustrating a cross-sectional configuration of a photodetector element 4 according to a third modification of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 4 is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 4 of this modification has two photoelectric conversion units 10, 60 and one photoelectric conversion region 32 stacked in the vertical direction.

[0116] The photoelectric conversion units 10 and 60 and the photoelectric conversion region 32 selectively detect light in different wavelength ranges and perform photoelectric conversion. For example, the photoelectric conversion unit 10 acquires a green (G) color signal. For example, the photoelectric conversion unit 60 acquires a blue (B) color signal. For example, the photoelectric conversion region 32 acquires a red (R) color signal. This allows the photodetector element 4 to acquire multiple types of color signals in one pixel without using a color filter.

[0117] The photoelectric conversion unit 60 has the same configuration as the photoelectric conversion unit 10. Specifically, like the photoelectric conversion unit 10, the photoelectric conversion unit 60 has a lower electrode 61, a photoelectric conversion layer 64, and an upper electrode 65 stacked in this order. The lower electrode 61 is made up of a plurality of electrodes (e.g., a charge readout electrode 61A and a charge storage electrode 61B), and an insulating layer 62 and an oxide semiconductor layer 63 are stacked in this order between the lower electrode 61 and the photoelectric conversion layer 64. Of the lower electrode 61, the charge readout electrode 61A is electrically connected to the oxide semiconductor layer 63 through an opening 62H provided in the insulating layer 62. Note that the oxide semiconductor layer 63 may be omitted.

[0118] A through electrode 66 is connected to the charge readout electrode 61A, which penetrates the interlayer insulating layer 67 and the photoelectric conversion unit 10 and is electrically connected to the charge readout electrode 11A of the photoelectric conversion unit 10. Furthermore, the charge readout electrode 61A is electrically connected to a floating diffusion FD provided in the semiconductor substrate 30 via the through electrodes 34 and 66, and can temporarily store charges generated in the photoelectric conversion layer 64. Furthermore, the charge readout electrode 61A is electrically connected to an amplifier transistor AMP and the like provided in the semiconductor substrate 30 via the through electrodes 34 and 66.

[0119] In the photodetector element 4, a high-refractive-index member 53 and a low-refractive-index member 54 are respectively arranged above the photoelectric conversion unit 60, which is arranged closer to the light incident side S1 of the photoelectric conversion units 10 and 60. In the photodetector element 4, the charge readout electrode 11A and the charge storage electrode 11B of the photoelectric conversion unit 10 and the charge readout electrode 61A and the charge storage electrode 61B of the photoelectric conversion unit 60 are respectively provided at approximately the same positions in a plan view. Therefore, by arranging the high-refractive-index member 53 above the charge storage electrode 61B of the photoelectric conversion unit 60 and the low-refractive-index member 54 above the charge readout electrode 61A, incident light is guided to the effective region X1 of each of the photoelectric conversion units 10 and 60.

[0120] (2-4. Modification 4) Fig. 17 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector element (photodetector element 5A) according to Modification 4 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5A is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5A constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0121] In the above embodiment, an example was shown in which the high-refractive-index member 53 and the low-refractive-index member 54 are provided on the upper electrode 15 of the photoelectric conversion unit 10, but this is not limited thereto. In the photodetector element 5A of this modification, similar to the first modification, color filters 55R, 55G, and 55B are arranged in a Bayer pattern between the protective layer 51 and the on-chip lens 52 for each unit pixel P. The high-refractive-index member 53 and the low-refractive-index member 54 are positioned in the thickness direction (Z-axis direction) within the protective layer 51 depending on the wavelength of light transmitted through the color filters 55R, 55G, and 55B and the position of the unit pixel P in the pixel unit 100A. Furthermore, in the above embodiment, an example was shown in which the high-refractive-index member 53 and the low-refractive-index member 54 have the same thickness, but this is not limited thereto. The high-refractive-index member 53 and the low-refractive-index member 54 may have different thicknesses and sizes depending on the wavelength of light transmitted through the color filters 55R, 55G, and 55B and the position of the unit pixel P in the pixel unit 100A. Except for this point, the photodetector element 5A has substantially the same configuration as the photodetector element 1 of the above embodiment.

[0122] Even with this configuration, the photodetector element 5A of this modification can achieve the same effects as those of the above embodiment.

[0123] (2-5. Modification 5) FIG. 18 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a light-detecting element (light-detecting element 5A) according to Modification 5 of the present disclosure.

[0124] The photodetector element 5A may perform pupil correction by shifting the on-chip lens 52, the high refractive index member 53, the low refractive index member 54, and the color filters 55R, 55G, and 55B in the incident direction of the light L according to the position (image height position) in the pixel unit 100A. This makes it possible to suppress light loss and color mixing in pixels that are far from the optical center of the pixel unit 100A, in addition to the effects of the above-described embodiment.

[0125] (2-6. Modification 6) Fig. 19 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5B) according to Modification 6 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5B is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5B constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0126] In the above embodiment, an example has been shown in which the high-refractive-index members 53 and the low-refractive-index members 54 are provided in the protective layer 51, but the present invention is not limited to this. In the photodetector element 5B of this modification, similar to the above-described modification 4, color filters 55R, 55G, and 55B are arranged in a Bayer pattern between the protective layer 51 and the on-chip lens 52 for each unit pixel P. The high-refractive-index members 53 and the low-refractive-index members 54 are arranged in the color filters 55R, 55G, and 55B, respectively. Except for this point, the photodetector element 5B has substantially the same configuration as the photodetector element 1 of the above-described embodiment and modification 4.

[0127] Even with this configuration, the photodetector element 5B of this modified example can achieve the same effects as those of the above embodiment.

[0128] (2-7. Modification 7) Fig. 20 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5C) according to Modification 7 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5C is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5C constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0129] In the above embodiment, an example has been shown in which the high-refractive-index members 53 and the low-refractive-index members 54 are provided in the protective layer 51, but the present invention is not limited to this. In the photodetector element 5C of this modification, similar to the above-described modification 4, color filters 55R, 55G, and 55B are arranged in a Bayer pattern between the protective layer 51 and the on-chip lens 52 for each unit pixel P. The high-refractive-index members 53 and the low-refractive-index members 54 are arranged on these color filters 55R, 55G, and 55B, respectively. Except for this point, the photodetector element 5C has substantially the same configuration as the photodetector element 1 of the above-described embodiment and modification 4.

[0130] Even with this configuration, the photodetector element 5C of this modified example can achieve the same effects as those of the above embodiment.

[0131] (2-8. Modification 8) Fig. 21 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5D) according to Modification 8 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5D is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5D constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0132] In the above embodiment, an example was shown in which the high refractive index members 53 and the low refractive index members 54 were provided in the protective layer 51, but the present invention is not limited to this. In the photodetector element 5D of this modification, the high refractive index members 53 and the low refractive index members 54 are embedded in the upper electrode 15 of the photoelectric conversion unit 10. Except for this point, the photodetector element 5D has substantially the same configuration as the photodetector element 1 of the above embodiment and modification 4.

[0133] Similarly to the fourth modification, the photodetector element 5D of this modification further includes color filters 55R, 55G, and 55B arranged in a Bayer pattern between the protective layer 51 and the on-chip lens 52 for each unit pixel P. The thicknesses of the high-refractive-index members 53 and the low-refractive-index members 54 are not limited, and as shown in the fourth to seventh modifications, their formation positions are not particularly limited. That is, assuming that the height of the high-refractive-index members 53 is h1, the height of the low-refractive-index members 54 is h2, the thickness of the upper electrode 15 is h3, the thickness of the protective layer 51 is h4, and the thickness of the color filter 55 is h5, the heights of the high-refractive-index members 53 and the low-refractive-index members 54 and the thicknesses of the upper electrode 15, the protective layer 51, and the color filter 55 only need to satisfy the relationship of the following mathematical formula (4). For example, a portion of the high-refractive-index member 53 embedded in the upper electrode 15 (e.g., the high-refractive-index member 53 arranged in the blue pixel Pb) may protrude into the color filter 55B, as shown in FIG. 21 . (Equation 4) h1, h2≦h3+h4+h5 (4)

[0134] Even with this configuration, the photodetector element 5D of this modification can achieve the same effects as those of the above embodiment.

[0135] (2-9. Modification 9) Fig. 22 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5E) according to Modification 9 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5E is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5E constitutes one pixel (unit pixel P) that is repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0136] In the above embodiment, an example has been shown in which one high-refractive-index member 53 is provided for each unit pixel P, but the present invention is not limited to this. In the photodetector element 5E of this modification, similar to the above modification 4, color filters 55R, 55G, and 55B are arranged in a Bayer pattern between the protective layer 51 and the on-chip lens 52 for each unit pixel P, and the high-refractive-index member 53 is arranged on one or both of the lower and upper surfaces of the color filters 55R, 55G, and 55B. Except for this point, the photodetector element 5E has substantially the same configuration as the photodetector element 1 of the above embodiment and modification 4.

[0137] In this way, a plurality of high-refractive-index members 53 may be provided in the Y-axis direction of each unit pixel P. Although not shown, a plurality of low-refractive-index members 54 may also be provided in the Y-axis direction of each unit pixel P. Even with such a configuration, the photodetector element 5E of this modified example can achieve the same effects as those of the above embodiment.

[0138] (2-10. Modification 10) FIG. 23A is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5F) according to Modification 10 of the present disclosure. FIG. 23B is a schematic diagram illustrating an example of a pixel configuration of a photodetector device 100 having the photodetector element 1 illustrated in FIG. 23A. Like the photodetector element 1 of the above embodiment, the photodetector element 5F is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5F constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device illustrated in FIG. 29, for example.

[0139] In the above embodiment, an example was shown in which the high-refractive-index member 53 was provided above the charge storage electrode 11B and the low-refractive-index member 54 was provided above the charge readout electrode 11A, spaced apart from each other, but this is not limited to this. In the photodetection element 5F of this modified example, a low-refractive-index member 54 having the same shape as the charge readout electrode 11A is disposed above the charge readout electrode 11A, and high-refractive-index members 53 are provided around it, continuing to multiple unit pixels P. In this modified example, the high-refractive-index member 53 and the low-refractive-index member 54 are in contact with each other. Except for this point, the photodetection element 5F has substantially the same configuration as the photodetection element 1 of the above embodiment.

[0140] Even with this configuration, the photodetector element 5F of this modification can achieve the same effects as those of the above embodiment.

[0141] (2-11. Modification 11) FIG. 24A is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector element (photodetector element 5G) according to Modification 11 of the present disclosure. FIG. 24B is a schematic diagram illustrating an example of a pixel configuration of a photodetector device 100 having the photodetector element 1 illustrated in FIG. 24A, and FIG. 24A illustrates a cross section corresponding to line V-V illustrated in FIG. 24B. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5G is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5G constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device illustrated in FIG. 29, for example.

[0142] In the above embodiment, an example was shown in which one high-refractive-index member 53 was provided above the charge storage electrode 11B and one low-refractive-index member 54 was provided above the charge readout electrode 11A, but this is not limited to this. In the photodetector element 5G of this modified example, four low-refractive-index members 54 are arranged spaced apart from each other for each pixel unit 1a, one for each unit pixel P, above the charge readout electrode 11A shared by the four unit pixels P. Furthermore, in the photodetector element 5G of this modified example, multiple (four in this example) high-refractive-index members 53 are arranged spaced apart from each other above the charge storage electrode 11B, respectively, for each of the four unit pixels P that make up the pixel unit 1a. Except for this point, the photodetector element 5G has substantially the same configuration as the photodetector element 1 of the above embodiment.

[0143] In this way, when the width of the high refractive index member 53 is W1, the width of the low refractive index member 54 is W2, and the width of one side of the pixel is W3, the widths of the high refractive index member 53, the low refractive index member 54, and the pixel may satisfy the relationship of the following mathematical formula (1): W1, W2≦2W3 (1) (Mathematical Formula 1)

[0144] Furthermore, when the width of the effective region X1 is W4 and the width of the ineffective region X2 is W5, the widths of the high refractive index member 53, the low refractive index member 54, the effective region X1, and the ineffective region X2 need only satisfy the relationships of the following formulas (2) and (3): (Formula 2) W1, W2≦W4 (2) (Formula 3) W1, W2≦W5 (3)

[0145] Furthermore, when the distance between the high refractive index members 53 and the low refractive index members 54 arranged in a straight line is P1, the pixel pitch is P2, the pitch of the effective area X1 is P3, and the pitch of the ineffective area X2 is P4, the distance between the high refractive index members 53 and the low refractive index members 54, the pitch of the pixels, the effective area X1, and the pitch of the ineffective area X2 may satisfy the relationships of the following formulas (5) to (7). (Formula 5) P1≦P2 (5) (Formula 6) P1≦P3 (6) (Formula 7) P1≦P4 (7)

[0146] The four high-refractive-index members 53 arranged above the charge storage electrode 11B include high-refractive-index members 53A and 54B having mutually different refractive indices. When the refractive index of the protective layer 51 is n1, the refractive index of the high-refractive-index member 53A is n2, the refractive index of the high-refractive-index member 53B is n3, and the refractive index of the low-refractive-index member 54 is n4, the refractive indices satisfy the relationship n3>n2>n1>n4, for example.

[0147] Even with this configuration, the photodetector element 5G of this modification can achieve the same effects as those of the above embodiment.

[0148] (2-12. Modification 12) Fig. 25 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5H) according to Modification 12 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5H is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5H constitutes one pixel (unit pixel P) repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0149] The photodetector 5H of this modification has antireflection films 56A, 56B, and 56C provided on either or both of the upper and lower surfaces of the high-refractive-index member 53 and the low-refractive-index member 54. Except for this point, the photodetector 5H has substantially the same configuration as the photodetector 1 of the above-described embodiment and modification 4.

[0150] Antireflection films 56A and 56B provided on the upper and lower surfaces of high-refractive-index member 53 each have a refractive index between that of protective layer 51 and that of high-refractive-index member 53. Antireflection film 56C provided on the upper surface of low-refractive-index member 54 has a refractive index between that of protective layer 51 and that of low-refractive-index member 54.

[0151] In this manner, in the light-detecting element 5H of this modified example, anti-reflection films 56A, 56B, 56C are provided on either or both of the upper and lower surfaces of the high-refractive-index member 53 and the low-refractive-index member 54. This makes it possible to reduce the surface reflection of each of the high-refractive-index member 53 and the low-refractive-index member 54 compared to the above embodiment, thereby further improving sensitivity.

[0152] (2-13. Modification 13) Fig. 26 is a schematic diagram illustrating an example of a cross-sectional configuration of a main part of a photodetector (photodetector element 5I) according to Modification 13 of the present disclosure. Similar to the photodetector element 1 of the above embodiment, the photodetector element 5I is a photodetector element such as a CMOS image sensor used in electronic devices such as digital still cameras and video cameras. The photodetector element 5I constitutes one pixel (unit pixel P) that is repeatedly arranged in an array in the pixel section 100A of the photodetector device shown in Fig. 29, for example.

[0153] In the photodetector 5I of this modification, a high-refractive-index member 57 having a refractive index higher than that of the protective layer 51 is provided within the protective layer 51 across a plurality of unit pixels P, and the high-refractive-index member 57 contains the high-refractive-index member 53 and the low-refractive-index member 54. Except for this point, the photodetector 5I has substantially the same configuration as the photodetector 1 of the above-described embodiment and modification 4.

[0154] The high refractive index member 57 has a refractive index higher than that of the protective layer 51 and higher than that of the high refractive index member 53 contained therein.

[0155] Even with this configuration, the photodetector element 5I of this modification can achieve the same effects as those of the above embodiment.

[0156] (2-14. Modification 14) Figures 27A to 27G schematically show examples of the planar shapes of the high-refractive-index members 53 and the low-refractive-index members 54. The planar shapes of the high-refractive-index members 53 and the low-refractive-index members 54 may be rectangular as shown in Figure 27A or triangular as shown in Figure 27B. The planar shapes of the high-refractive-index members 53 and the low-refractive-index members 54 may be circular as shown in Figure 27C or elliptical as shown in Figure 27D. The planar shapes of the high-refractive-index members 53 and the low-refractive-index members 54 may be rectangular and circular frames as shown in Figures 27E and 28F, or may be cross-shaped as shown in Figure 27G.

[0157] (2-15. Modification 15) Figures 28A to 28D are schematic diagrams showing examples of the cross-sectional shapes of the high-refractive-index members 53 and the low-refractive-index members 54. The cross-sectional shapes of the high-refractive-index members 53 and the low-refractive-index members 54 are not limited to columnar shapes, including cylindrical and polygonal columnar shapes, as shown in the above-described embodiments, and may be conical or polygonal pyramidal as shown in Figure 28A, or may be substantially hemispherical as shown in Figure 28B. The cross-sectional shapes of the high-refractive-index members 53 and the low-refractive-index members 54 may have a rounded columnar top surface as shown in Figure 28C, or may be trapezoidal as shown in Figure 28D.

[0158] 3. Application Examples Application Example 1 FIG. 29 shows an example of the overall configuration of a photodetector (photodetector 100) including the photodetector element (for example, the photodetector element 1) shown in FIG. 3 and the like.

[0159] The photodetector 100 is, for example, a CMOS image sensor that captures incident light (image light) from a subject via an optical lens system (not shown), converts the amount of incident light imaged on an imaging surface into an electrical signal for each pixel, and outputs the signal as a pixel signal. The photodetector 100 has a pixel section 100A as an imaging area on a semiconductor substrate 30, and also has, in a peripheral region of the pixel section 100A, for example, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and input / output terminals 116.

[0160] The pixel section 100A has, for example, a plurality of unit pixels P arranged two-dimensionally in a matrix. For example, pixel drive lines Lread (specifically, row selection lines and reset control lines) are wired to each unit pixel P for each pixel row, and vertical signal lines Lsig are wired to each pixel column. The pixel drive lines Lread transmit drive signals for reading signals from the pixels. One end of each pixel drive line Lread is connected to an output terminal of the vertical drive circuit 111 corresponding to each row.

[0161] The vertical drive circuit 111 is a pixel drive unit that includes a shift register, an address decoder, etc., and drives each unit pixel P of the pixel unit 100A, for example, row by row. Signals output from each unit pixel P of a pixel row selected and scanned by the vertical drive circuit 111 are supplied to a column signal processing circuit 112 through each vertical signal line Lsig. The column signal processing circuit 112 is configured with an amplifier, a horizontal selection switch, etc., provided for each vertical signal line Lsig.

[0162] The horizontal drive circuit 113 is configured with a shift register, an address decoder, etc., and scans and sequentially drives each horizontal selection switch of the column signal processing circuit 112. By selective scanning by this horizontal drive circuit 113, signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to horizontal signal lines 121 and transmitted to the outside of the semiconductor substrate 30 through the horizontal signal lines 121.

[0163] The output circuit 114 processes and outputs signals sequentially supplied from each of the column signal processing circuits 112 via the horizontal signal line 121. The output circuit 114 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, and the like, for example.

[0164] The circuit portion consisting of the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, and the output circuit 114 may be formed directly on the semiconductor substrate 30, or may be disposed on an external control IC. Furthermore, these circuit portions may be formed on another substrate connected by a cable or the like.

[0165] The control circuit 115 receives a clock and data instructing an operation mode from outside the semiconductor substrate 30, and outputs data such as internal information of the photodetector 100. The control circuit 115 further has a timing generator that generates various timing signals, and controls the driving of peripheral circuits such as the vertical drive circuit 111, the column signal processing circuit 112, and the horizontal drive circuit 113 based on the various timing signals generated by the timing generator.

[0166] The input / output terminal 116 is used to exchange signals with the outside.

[0167] (Application Example 2) Furthermore, the photodetector 100 as described above can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, or other devices with imaging functions.

[0168] FIG. 30 is a block diagram showing an example of the configuration of electronic device 1000. As shown in FIG.

[0169] As shown in Figure 30, electronic device 1000 includes an optical system 1001, a photodetector 100, and a DSP (Digital Signal Processor) 1002, and is configured by connecting DSP 1002, memory 1003, display device 1004, recording device 1005, operation system 1006, and power supply system 1007 via a bus 1008, and is capable of capturing still images and moving images.

[0170] The optical system 1001 is configured to have one or more lenses, and receives incident light (image light) from an object and forms an image on the imaging surface of the photodetector 100 .

[0171] The above-described photodetector 100 is applied as the photodetector 100. The photodetector 100 converts the amount of incident light imaged on an imaging surface by an optical system 1001 into an electrical signal on a pixel-by-pixel basis and supplies the signal to a DSP 1002 as a pixel signal.

[0172] The DSP 1002 performs various signal processing on the signal from the photodetector 100 to acquire an image, and temporarily stores the image data in a memory 1003. The image data stored in the memory 1003 is recorded in a recording device 1005 or supplied to a display device 1004 to display the image. An operation system 1006 accepts various operations by a user and supplies operation signals to each block of the electronic device 1000, and a power supply system 1007 supplies power necessary to drive each block of the electronic device 1000.

[0173] Application Example 3 Fig. 31A schematically illustrates an example of the overall configuration of a light detection system 2000 including the light detection device 100. Fig. 31B illustrates an example of the circuit configuration of the light detection system 2000. The light detection system 2000 includes a light emitting device 2001 serving as a light source unit that emits infrared light L2, and a light detection device 2002 serving as a light receiving unit having a light detection element. The light detection device 100 described above can be used as the light detection device 2002. The light detection system 2000 may further include a system control unit 2003, a light source driving unit 2004, a sensor control unit 2005, a light source side optical system 2006, and a camera side optical system 2007.

[0174] The photodetector 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by the object (measurement target) 2100 ( FIG. 31A ). Light L2 is light emitted by the light-emitting device 2001 and then reflected by the object 2100. Light L1 is, for example, visible light, and light L2 is, for example, infrared light. Light L1 can be detected by a photoelectric conversion unit in the photodetector 2002, and light L2 can be detected by a photoelectric conversion region in the photodetector 2002. Image information of the object 2100 can be obtained from light L1, and distance information between the object 2100 and the photodetector system 2000 can be obtained from light L2. The photodetector system 2000 can be installed in, for example, an electronic device such as a smartphone or a mobile object such as a car. The light-emitting device 2001 can be configured, for example, by a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can be, for example, an iTOF method, but is not limited to this. In the iTOF method, the photoelectric conversion unit can measure the distance to the subject 2100, for example, by using the time-of-flight (TOF) of light. The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can also be, for example, a structured light method or a stereo vision method. For example, in the structured light method, a predetermined pattern of light is projected onto the subject 2100, and the distance between the photodetector system 2000 and the subject 2100 can be measured by analyzing the distortion of the pattern. In addition, in the stereo vision method, for example, two or more cameras are used to acquire two or more images of the subject 2100 viewed from two or more different viewpoints, thereby measuring the distance between the photodetector system 2000 and the subject. The light emitting device 2001 and the light detecting device 2002 can be controlled synchronously by a system control unit 2003 .

[0175] 4. Application Example Application Example to Endoscopic Surgery System The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0176] FIG. 32 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0177] 32 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0178] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0179] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0180] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0181] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0182] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0183] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing the surgical site, etc.

[0184] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0185] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0186] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0187] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0188] The light source device 11203 may also be configured to supply light in a predetermined wavelength range compatible with special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light compatible with such special light observation.

[0189] FIG. 33 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0190] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0191] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0192] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0193] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately after the objective lens.

[0194] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0195] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0196] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0197] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0198] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0199] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0200] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0201] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0202] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0203] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 based on the image signal subjected to image processing by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0204] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0205] In the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0206] The above describes an example of an endoscopic surgery system to which the technology disclosed herein can be applied. The technology disclosed herein can be applied to the imaging unit 11402 among the components described above. Applying the technology disclosed herein to the imaging unit 11402 improves detection accuracy.

[0207] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0208] (Application Example to Mobile Object) The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile object, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0209] FIG. 34 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0210] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 34, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0211] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0212] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0213] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0214] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0215] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0216] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0217] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0218] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0219] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to vehicle occupants or the outside of the vehicle. In the example of Fig. 34, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0220] FIG. 35 is a diagram showing an example of the installation position of the imaging unit 12031.

[0221] In FIG. 35, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0222] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0223] 35 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0224] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0225] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0226] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0227] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0228] The foregoing has described an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the image capture unit 12031 of the above-described configuration. Specifically, the photodetector element (e.g., photodetector element 1) according to the above-described embodiment and its modified examples 1 to 15 can be applied to the image capture unit 12031. By applying the technology according to the present disclosure to the image capture unit 12031, it is possible to obtain a high-resolution captured image with little noise, thereby enabling high-precision control using the captured image in the mobile object control system.

[0229] Although the present technology has been described above by way of the embodiments, Modifications 1 to 15, and application examples, the present disclosure is not limited to the above-described embodiments, etc., and various modifications are possible. For example, while the above-described embodiments, etc., show examples in which electrons are read out from the lower electrode 11 as signal charges, the present disclosure is not limited to this, and holes may be read out from the lower electrode 11 as signal charges.

[0230] Furthermore, in the above embodiment, the photodetector element 1 is configured by stacking the photoelectric conversion unit 10 using an organic material that detects green light (G) and the photoelectric conversion region 32B and the photoelectric conversion region 32R that detect blue light (B) and red light (R), respectively, but the present disclosure is not limited to this structure. That is, the photoelectric conversion unit using an organic material may be configured to detect red light (R) or blue light (B), or the photoelectric conversion region made of an inorganic material may be configured to detect green light (G).

[0231] Furthermore, the number and ratio of the photoelectric conversion units using these organic materials and the photoelectric conversion regions made of inorganic materials are not limited. Furthermore, the photoelectric conversion units using organic materials and the photoelectric conversion regions made of inorganic materials are not limited to a structure in which they are stacked vertically, and they may be arranged in parallel along the substrate surface.

[0232] Furthermore, in the above-described embodiments, the configuration of a back-illuminated photodetector element has been exemplified, but the present disclosure can also be applied to a front-illuminated photodetector element.

[0233] Furthermore, the photodetector element 1 and the photodetector device 100 disclosed herein do not necessarily have to include all of the components described in the above embodiments, and may instead include other components. For example, the photodetector device 100 may be provided with a shutter for controlling the incidence of light on the photodetector element 1, or may be provided with an optical cut filter depending on the purpose of the photodetector device 100. Furthermore, the arrangement of the pixels (Pr, Pg, Pb) that detect red light (R), green light (G), and blue light (B) may be an interline arrangement, a G-stripe RB checkerboard arrangement, a G-stripe RB complete checkerboard arrangement, a checkerboard complementary color arrangement, a stripe arrangement, a diagonal stripe arrangement, a primary color color difference arrangement, a field color difference sequential arrangement, a frame color difference sequential arrangement, a MOS type arrangement, an improved MOS type arrangement, a frame interleaved arrangement, or a field interleaved arrangement, in addition to the Bayer arrangement.

[0234] Although the above-described embodiments and the like have shown examples in which the photodetector 1 is used as an image sensor, the photodetector 1 of the present disclosure may also be applied to a solar cell. When applied to a solar cell, the photoelectric conversion layer is preferably designed to broadly absorb wavelengths of, for example, 400 nm to 800 nm.

[0235] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0236] The present technology can also be configured as follows. According to the present technology configured as follows, incident light is guided to a desired region of a photoelectric conversion layer, thereby improving sensitivity. [1] A photodetector comprising: a photoelectric conversion layer; a first structure having a refractive index higher than its surroundings and arranged on the light incident side of the photoelectric conversion layer above a first region where carriers generated by photoelectric conversion accumulate; and a second structure having a refractive index higher than its surroundings and arranged on the light incident side of the photoelectric conversion layer above a second region where the carriers do not accumulate. [2] The photodetector according to [1], wherein the first structure and the second structure are provided at different positions in the thickness direction of the photoelectric conversion layer. [3] The photodetector according to [1] or [2], further comprising: a first electrode disposed on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode disposed opposite the first electrode with the photoelectric conversion layer therebetween; and a protective layer stacked on the light incident side of the second electrode, wherein the first structure and the second structure are provided within the protective layer. [4] The photodetector according to any one of [1] to [3], further comprising: a first electrode disposed on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode disposed opposite the first electrode with the photoelectric conversion layer therebetween; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided within the color filter. [5] A photodetector element according to any one of [1] to [3], further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided on the color filter.[6] The photodetector according to any one of [1] to [3], further comprising: a first electrode disposed on the side opposite to the light incident side of the photoelectric conversion layer; and a second electrode disposed opposite the first electrode with the photoelectric conversion layer interposed therebetween, wherein at least a portion of the first structure and the second structure are embedded in the second electrode. [7] The photodetector according to any one of [1] to [3], further comprising: a first electrode disposed on the side opposite to the light incident side of the photoelectric conversion layer; a second electrode disposed opposite the first electrode with the photoelectric conversion layer interposed therebetween; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided at least either within the protective layer or on the color filter. [8] The photodetector according to any one of [1] to [7], wherein the first structure and the second structure are in contact with each other in an in-plane direction. [9] The photodetector according to any one of [1] to [8], further comprising: a first electrode disposed on the side opposite to the light incident side of the photoelectric conversion layer; and a second electrode disposed opposite the first electrode with the photoelectric conversion layer interposed therebetween, wherein the first electrode includes a charge storage electrode above which the carriers can be stored and a charge readout electrode above which the carriers can be read out, wherein one or more of the first structures are disposed above the charge storage electrode, and wherein one or more of the second structures are disposed above the charge readout electrode.

[10] The photodetector according to [9], wherein the plurality of first structures have refractive indices different from one another.

[11] The photodetector according to [9] or

[10] , wherein the first structure has substantially the same planar shape as the charge readout electrode in a plan view.

[12] The photodetector element according to any one of [9] to

[11] , wherein a plurality of pixels are arranged in a two-dimensional array, and the charge storage electrode, the charge readout electrode, the first structure, and the second structure are provided for each pixel, respectively.

[13] The photodetector according to any one of [9] to

[11] , wherein a plurality of pixels are arranged in a two-dimensional array, the charge storage electrode and the first structure are provided for each pixel, and the charge readout electrode and the second structure are each provided for every four of the pixels arranged in 2 rows and 2 columns.

[14] The photodetector according to any one of [1] to

[13] , further comprising a third structure having a refractive index lower than that of the first structure and higher than that of the second structure, the third structure containing the first structure and the second structure.

[15] The photodetector according to any one of [1] to

[14] , wherein at least one of the first structure and the second structure has an antireflection film on at least one of the light incident side and the side opposite to the light incident side.

[16] The photodetector element according to any one of [1] to

[15] , wherein the first structure and the second structure each have a cylindrical shape, a polygonal pillar shape, a cone shape, a polygonal pyramid shape, or a substantially hemispherical shape.

[17] The photodetector element according to any one of [1] to

[16] , wherein a plurality of pixels including a first pixel and a second pixel that perform photoelectric conversion on light of different wavelength bands are arranged in a two-dimensional array, and the first structure has a different size or shape for the first pixel and the second pixel.

[18] The photodetector element according to any one of [1] to

[17] , wherein a plurality of pixels are arranged in a two-dimensional array, and the first structure and the second structure are respectively provided for each of the plurality of pixels and are arranged shifted in the light incident direction depending on the position of the pixel.

[19] The photodetector element according to any one of [9] to

[18] , wherein the first region and the second region are included within the plane of the photoelectric conversion layer.

[20] The photodetector according to any one of [9] to

[18] , further comprising an oxide semiconductor layer provided between the first electrode and the photoelectric conversion layer, wherein the first region and the second region are included within a plane of the oxide semiconductor layer.

[21] The photodetector element according to any one of [1] to

[20] , wherein a plurality of pixels are arranged in a two-dimensional array, and when a width of the first structure is W1, a width of the second structure is W2, and a width of one side of the pixel is W3, the respective widths of the first structure, the second structure, and the pixel have a relationship represented by the following mathematical formula (1): (Mathematical Formula 1) W1, W2≦2W3 (1)

[22] Furthermore, when a width of the first region is W4 and a width of the second region is W5, the respective widths of the first structure, the second structure, the first region, and the second region have a relationship represented by the following mathematical formula (2) and mathematical formula (3). (Equation 2) W1, W2≦W4 (2) (Equation 3) W1, W2≦W5 (3)

[23] The light-detecting element according to any one of items [1] to

[22] , further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the height of the first structure and the second structure and the thickness of the second electrode, the protective layer, and the color filter have a relationship represented by the following equation (4), where h1 is the height of the second structure, h2 is the thickness of the second electrode, h3 is the thickness of the protective layer, and h5 is the thickness of the color filter. (Equation 4) h1, h2≦h3+h4+h5 (4)

[24] The photodetector element according to any one of [1] to

[23] , wherein a plurality of pixels are arranged in a two-dimensional array, and when a distance between the first structure and the second structure arranged in a straight line is P1, a pitch of the pixels is P2, a pitch of the first regions is P3, and a pitch of the second regions is P4, the distance between the first structure and the second structure, and the respective pitches of the pixels, the first regions, and the second regions have the relationships of the following equations (5) to (7).(Equation 5) P1≦P2 (5) (Equation 6) P1≦P3 (6) (Equation 7) P1≦P4 (7)

[25] A photodetector comprising a plurality of pixels, each having one or a plurality of photodetection elements, wherein the photodetection elements include: a photoelectric conversion layer; a first structure having a refractive index higher than its surroundings and arranged above a first region, on the light incident side of the photoelectric conversion layer, where carriers generated by photoelectric conversion are accumulated; and a second structure having a refractive index higher than its surroundings and arranged above a second region, on the light incident side of the photoelectric conversion layer, where the carriers are not accumulated.

[0237] This application claims priority based on Japanese Patent Application No. 2024-090314, filed on June 3, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0238] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A photodetector comprising: a photoelectric conversion layer; a first structure having a refractive index higher than its surroundings and arranged above a first region on the light incident side of the photoelectric conversion layer where carriers generated by photoelectric conversion accumulate; and a second structure having a refractive index higher than its surroundings and arranged above a second region on the light incident side of the photoelectric conversion layer where the carriers do not accumulate.

2. The photodetector element according to claim 1, wherein the first structure and the second structure are provided at different positions in the thickness direction of the photoelectric conversion layer.

3. The photodetector element described in claim 1, further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer stacked on the light incident side of the second electrode, wherein the first structure and the second structure are provided within the protective layer.

4. The photodetector element of claim 1, further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided within the color filter.

5. The photodetector element of claim 1, further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided on the color filter.

6. The photodetector element according to claim 1, further comprising: a first electrode disposed on the opposite side of the photoelectric conversion layer from the light incident side; and a second electrode disposed opposite the first electrode with the photoelectric conversion layer interposed therebetween, wherein at least a portion of the first structure and the second structure are embedded in the second electrode.

7. A photodetector element as described in claim 1, further comprising: a first electrode arranged on the opposite side of the photoelectric conversion layer from the light incident side; a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between; and a protective layer and a color filter stacked in this order on the light incident side of the second electrode, wherein the first structure and the second structure are provided at least either within the protective layer or on the color filter, respectively.

8. The photodetector element according to claim 1, wherein the first structure and the second structure are in contact with each other in an in-plane direction.

9. The photodetector element according to claim 1, further comprising: a first electrode arranged on the side of the photoelectric conversion layer opposite the light incident side; and a second electrode arranged opposite the first electrode with the photoelectric conversion layer in between, wherein the first electrode includes a charge storage electrode above which the carriers can be stored and a charge readout electrode above which the carriers are read out, wherein one or more of the first structures are arranged above the charge storage electrode, and one or more of the second structures are arranged above the charge readout electrode.

10. The photodetector element according to claim 9, wherein the plurality of first structures have refractive indices different from each other.

11. The light-detecting element according to claim 9, wherein the first structure has substantially the same planar shape as the charge readout electrode in a plan view.

12. The photodetector element according to claim 9, wherein a plurality of pixels are arranged in a two-dimensional array, and the charge storage electrode, the charge readout electrode, the first structure, and the second structure are provided for each pixel, respectively.

13. A photodetector element according to claim 9, wherein a plurality of pixels are arranged in a two-dimensional array, the charge storage electrode and the first structure are each provided for each pixel, and the charge readout electrode and the second structure are each provided one for every four of the pixels arranged in two rows and two columns.

14. The light-detecting element according to claim 1, wherein at least one of the first structure and the second structure has an anti-reflection film on at least one of the light incident side and the side opposite to the light incident side.

15. The light detection element according to claim 1, wherein the first structure and the second structure each have a cylindrical shape, a polygonal prism shape, a cone shape, a polygonal pyramid shape, or a substantially hemispherical shape.

16. The photodetector element according to claim 1, wherein a plurality of pixels including a first pixel and a second pixel that perform photoelectric conversion on light of different wavelength bands are arranged in a two-dimensional array, and the first structure has a different size or shape for the first pixel and the second pixel.

17. A photodetector element as described in claim 1, wherein a plurality of pixels are arranged in a two-dimensional array, and the first structure and the second structure are provided for each of the plurality of pixels, and are arranged shifted in the light incident direction according to the position of the pixel.

18. The photodetector element according to claim 9, wherein the first region and the second region are included within the plane of the photoelectric conversion layer.

19. The photodetector element according to claim 9, further comprising an oxide semiconductor layer provided between the first electrode and the photoelectric conversion layer, wherein the first region and the second region are included within the plane of the oxide semiconductor layer.

20. A photodetection device comprising a plurality of pixels each provided with one or a plurality of photodetection elements, wherein the photodetection elements comprise: a photoelectric conversion layer; a first structure having a refractive index higher than the surrounding area and arranged above a first region on the light incident side of the photoelectric conversion layer where carriers generated by photoelectric conversion accumulate; and a second structure having a refractive index higher than the surrounding area and arranged above a second region on the light incident side of the photoelectric conversion layer where the carriers do not accumulate.

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