Light detection device, electronic equipment, and optical element

Abstract

To provide a light detection device which can be suppressed in deterioration of quality.SOLUTION: A light detection device of an embodiment of the present disclosure, comprises: a plurality of structures each having the size of a wavelength or less of an incident light; a light guiding portion which is provided in such a manner that it fills between the plurality of adjacent structures, and which includes a first medium and a second medium having refraction factors different from the refraction factor of each structure; and a photoelectric conversion portion which photoelectrically converts light entered via the light guiding portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to light detection devices, electronic devices, and optical elements. [Background technology]

[0002] An image sensor including a color separation lens array having a plurality of nanoposts has been proposed (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-69119 Summary of the Invention

[0004] In light detecting devices, there is a demand to suppress deterioration in quality.

[0005] It is desirable to provide a photodetection device capable of suppressing deterioration in quality.

[0006] An optical detection device according to one embodiment of the present disclosure includes a plurality of structures, each having a size equal to or smaller than the wavelength of incident light, a light guiding section having a first medium and a second medium arranged to fill the spaces between adjacent structures and each having a refractive index different from the refractive index of the structures, and a photoelectric conversion section that performs photoelectric conversion on the light incident through the light guiding section. An optical element according to one embodiment of the present disclosure comprises a plurality of structures, each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium arranged to fill the spaces between adjacent structures, each having a refractive index different from the refractive index of the structures. According to an embodiment of the present disclosure, an electronic device includes an optical system and a photodetector that receives light transmitted through the optical system. The photodetector includes a light guide having a plurality of structures each having a size equal to or smaller than the wavelength of the incident light, a first medium and a second medium that are provided to fill spaces between adjacent structures and have refractive indices different from the refractive index of the structures, and a photoelectric conversion unit that performs photoelectric conversion on the light incident through the light guide. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an example of a schematic configuration of an imaging device which is an example of a light detection device according to an embodiment of the present disclosure. [Diagram 2] 1 is a diagram illustrating an example of a pixel unit of an imaging device according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram illustrating an example of a pixel configuration of an imaging device according to an embodiment of the present disclosure. [Figure 4] 1 is a diagram illustrating an example of a cross-sectional configuration of an imaging device according to an embodiment of the present disclosure. [Figure 5A] 2 is a diagram illustrating an example of a planar configuration of a light guiding section of an imaging device according to an embodiment of the present disclosure. FIG. [Figure 5B] 2 is a diagram illustrating an example of a planar configuration of a light guiding section of an imaging device according to an embodiment of the present disclosure. FIG. [Figure 6A] FIG. 1 is a diagram illustrating an example of the configuration of an imaging device according to a comparative example. [Figure 6B] FIG. 1 is a diagram illustrating an example of the configuration of an imaging device according to a comparative example. [Figure 7A] 1 is a diagram illustrating an example of a configuration of an imaging device according to an embodiment of the present disclosure. [Figure 7B] 1 is a diagram illustrating an example of a configuration of an imaging device according to an embodiment of the present disclosure. [Figure 8] FIG. 1 is a diagram illustrating an example of the configuration of an imaging device according to a comparative example. [Figure 9] 1 is a diagram illustrating an example of a configuration of an imaging device according to an embodiment of the present disclosure. [Figure 10] 3A to 3C are diagrams for explaining a configuration example of a light guiding section of an imaging device according to an embodiment of the present disclosure. [Figure 11A] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 11B] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 11C] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 11D] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 11E] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 11F] 1A to 1C are diagrams illustrating an example of a manufacturing method for an imaging device according to an embodiment of the present disclosure. [Figure 12A] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12B] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12C] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12D] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12E] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12F] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12G] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12H] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12I] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 12J] 10A to 10C are diagrams illustrating another example of a method for manufacturing an imaging device according to an embodiment of the present disclosure [Figure 13] 11 is a diagram illustrating a configuration example of a light guiding section of an imaging device according to a first modified example of the present disclosure [Figure 14] 13 is a diagram illustrating a configuration example of a light guiding section of an imaging device according to a second modified example of the present disclosure. FIG. [Figure 15] FIG. 11 is a diagram illustrating an example of the configuration of an imaging device according to a third modified example of the present disclosure. [Figure 16] FIG. 1 is a block diagram illustrating an example of the configuration of an electronic device having an imaging device. [Figure 17] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 18] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. [Figure 19] 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 20] 2 is a block diagram showing an example of a functional configuration of a camera head and a CCU. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. Embodiment 2. Variations 3. Application Examples 4. Application Examples

[0009] <1. Preferred embodiment> Fig. 1 is a block diagram showing an example of a schematic configuration of an imaging device which is an example of a photodetection device according to an embodiment of the present disclosure. Fig. 2 is a diagram showing an example of a pixel unit of an imaging device according to an embodiment. A photodetection device is a device capable of detecting incident light. The imaging device 1 which is a photodetection device can receive light transmitted through an optical system and generate a signal. The imaging device 1 (photodetection device) has a plurality of pixels P having a photoelectric conversion unit, and is configured to perform photoelectric conversion of the incident light to generate a signal.

[0010] The photoelectric conversion unit of each pixel P of the imaging device 1 is, for example, a photodiode, and is configured to be capable of photoelectrically converting light. As shown in Fig. 2, the imaging device 1 has an area (pixel unit 100) in which a plurality of pixels P are two-dimensionally arranged in a matrix as an imaging area. The pixel unit 100 is a pixel array in which a plurality of pixels P are arranged, and can also be called a light receiving area.

[0011] The imaging device 1 captures incident light (image light) from a subject through an optical system (not shown) including an optical lens. The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can perform photoelectric conversion on the received light to generate a pixel signal. The imaging device 1 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging device 1 can be used in electronic devices such as digital still cameras, video cameras, and mobile phones.

[0012] As shown in Fig. 2, the incident direction of light from the subject is the Z-axis direction, the left-right direction on the paper perpendicular to the Z-axis direction is the X-axis direction, and the up-down direction on the paper perpendicular to the Z-axis and X-axis is the Y-axis direction. In the following figures, directions may be indicated based on the direction of the arrow in Fig. 2.

[0013] 1, the imaging device 1 includes, for example, a pixel driving unit 111, a signal processing unit 112, a control unit 113, and a processing unit 114 in a peripheral region of a pixel unit 100 (pixel array). The imaging device 1 also includes a plurality of control lines L1 and a plurality of signal lines L2.

[0014] The imaging device 1 is provided with a control line L1, which is a signal line capable of transmitting a signal for controlling the pixel P. In the pixel section 100, for example, a plurality of control lines L1 are wired for each pixel row composed of a plurality of pixels P arranged in the horizontal direction (row direction). The control line L1 is configured to transmit a control signal for reading out a signal from the pixel P. The control line L1 can also be said to be a pixel drive line that transmits a signal for driving the pixel P.

[0015] The imaging device 1 is also provided with a signal line L2 capable of transmitting a signal from the pixel P. In the pixel section 100, for example, the signal line L2 is wired for each pixel column made up of a plurality of pixels P aligned in the vertical direction (column direction). The signal line L2 is a vertical signal line and is configured to transmit a signal output from the pixel P.

[0016] The pixel driving unit 111 is composed of a shift register, an address decoder, etc. The pixel driving unit 111 is configured to be able to drive each pixel P of the pixel unit 100. The pixel driving unit 111 generates a signal for controlling the pixel P, and outputs the signal to each pixel P of the pixel unit 100 via a control line L1.

[0017] The pixel driving unit 111 generates, for example, a signal for controlling a transfer transistor of the pixel P, a signal for controlling a reset transistor, etc., and supplies these to each pixel P via a control line L1, as described below. The pixel driving unit 111 can control the reading of pixel signals from each pixel P. The pixel driving unit 111 can also be said to be a pixel control unit configured to be able to control each pixel P.

[0018] The signal processing unit 112 is configured to be able to execute signal processing of the input pixel signals. The signal processing unit 112 has, for example, a load circuit unit, an AD (Analog Digital) conversion unit, a horizontal selection switch, and the like. A signal output from each pixel P selected and scanned by the pixel driving unit 111 is input to the signal processing unit 112 via a signal line L2. The signal processing unit 112 can perform signal processing such as AD conversion of the pixel P signal and CDS (Correlated Double Sampling). The signal of each pixel P transmitted through each signal line L2 is subjected to signal processing by the signal processing unit 112 and output to the processing unit 114.

[0019] The processing unit 114 is configured to be able to execute signal processing on the input signal. The processing unit 114 is configured, for example, by a circuit that performs various types of signal processing on pixel signals. The processing unit 114 may include a processor and a memory. The processing unit 114 performs signal processing on pixel signals input from the signal processing unit 112, and outputs the processed pixel signals. The processing unit 114 can perform various types of signal processing, for example, noise reduction processing, tone correction processing, etc.

[0020] The control unit 113 is configured to be able to control each unit of the imaging device 1. The control unit 113 receives an externally provided clock, data instructing an operation mode, and the like, and can also output data such as internal information of the imaging device 1. The control unit 113 has a timing generator configured to be able to generate various timing signals. The control unit 113 controls the driving of peripheral circuits such as the pixel driving unit 111 and the signal processing unit 112 based on various timing signals (pulse signals, clock signals, and the like) generated by the timing generator. Note that the control unit 113 and the processing unit 114 may be configured integrally.

[0021] The pixel driving unit 111, the signal processing unit 112, the control unit 113, the processing unit 114, etc. may be provided on one semiconductor substrate, or may be provided separately on multiple semiconductor substrates. The imaging device 1 may have a structure (a stacked structure) formed by stacking multiple substrates.

[0022] [Pixel configuration] 3 is a diagram showing an example of the configuration of a pixel of an imaging device according to an embodiment. The pixel P has a photoelectric conversion unit 12, a transfer transistor 13, an FD (floating diffusion) 14, and a readout circuit 18. The readout circuit 18 is configured to be able to output a signal based on charges obtained by photoelectric conversion. The readout circuit 18 has, as an example, an amplification transistor 15, a selection transistor 16, and a reset transistor 17. Note that the readout circuit 18 may include the FD 14.

[0023] The transfer transistor 13, the amplification transistor 15, the selection transistor 16, and the reset transistor 17 are each a MOS transistor (MOSFET) having a gate, a source, and a drain terminal. In the example shown in Fig. 3, the transfer transistor 13, the amplification transistor 15, the selection transistor 16, and the reset transistor 17 are each composed of an NMOS transistor. The transistor of the pixel P may be composed of a PMOS transistor.

[0024] The photoelectric conversion unit 12 is configured to be capable of generating electric charges by photoelectric conversion. The photoelectric conversion unit 12 is, for example, a photodiode (PD) embedded in a semiconductor substrate, and converts incident light into electric charges. The photoelectric conversion unit 12 performs photoelectric conversion to generate electric charges according to the amount of received light.

[0025] The transfer transistor 13 is configured to be able to transfer charges photoelectrically converted by the photoelectric conversion unit 12 to the FD 14. As shown in Fig. 3, the transfer transistor 13 is controlled by a signal TRG to electrically connect or disconnect the photoelectric conversion unit 12 and the FD 14. The transfer transistor 13 can transfer charges photoelectrically converted and accumulated in the photoelectric conversion unit 12 to the FD 14.

[0026] The FD 14 is an accumulation unit and is configured to be able to accumulate the transferred electric charge. The FD 14 can accumulate the electric charge photoelectrically converted by the photoelectric conversion unit 12. The FD 14 can also be said to be a retention unit capable of retaining the transferred electric charge. The FD 14 accumulates the transferred electric charge and converts it into a voltage according to the capacitance of the FD 14.

[0027] The amplifying transistor 15 is configured to generate and output a signal based on the charge accumulated in the FD 14. As shown in Fig. 3, the gate of the amplifying transistor 15 is electrically connected to the FD 14, and a voltage converted by the FD 14 is input to the gate. The drain of the amplifying transistor 15 is connected to a power supply line to which a power supply voltage VDD is supplied, and the source of the amplifying transistor 15 is connected to a signal line L2 via a selection transistor 16. The amplifying transistor 15 can generate a signal based on the charge accumulated in the FD 14, i.e., a signal based on the voltage of the FD 14, and output the signal to the signal line L2.

[0028] The selection transistor 16 is configured to be capable of controlling the output of a pixel signal. The selection transistor 16 is configured to be controlled by a signal SEL and to be capable of outputting a signal from the amplification transistor 15 to a signal line L2. The selection transistor 16 can control the output timing of the pixel signal. The selection transistor 16 may be provided between a power supply line to which a power supply voltage VDD is applied and the amplification transistor 15. Furthermore, the selection transistor 16 may be omitted as necessary.

[0029] 3, the reset transistor 17 is electrically connected to a power line to which a power supply voltage VDD is applied, and configured to reset the charge of the pixel P. The reset transistor 17 is controlled by a signal RST, and can reset the charge accumulated in the FD 14 and reset the voltage of the FD 14. The reset transistor 17 can discharge the charge accumulated in the photoelectric conversion unit 12 via the transfer transistor 13.

[0030] The pixel driving unit 111 (see FIG. 1) supplies control signals to the gates of the transfer transistor 13, selection transistor 16, reset transistor 17, etc. of each pixel P via the above-mentioned control line L1 to turn the transistors on (conducting state) or off (non-conducting state). The multiple control lines L1 of the imaging device 1 include a line for transmitting a signal TRG that controls the transfer transistor 13, a line for transmitting a signal SEL that controls the selection transistor 16, a line for transmitting a signal RST that controls the reset transistor 17, etc.

[0031] The transfer transistor 13, selection transistor 16, reset transistor 17, etc. are on / off controlled by a pixel driving unit 111. The pixel driving unit 111 controls the readout circuit 18 of each pixel P to output a pixel signal from each pixel P to a signal line L2. The pixel driving unit 111 can control the reading out of the pixel signal of each pixel P to the signal line L2. The pixel driving unit 111 and the control unit 113 can be collectively referred to as a pixel control unit.

[0032] Fig. 4 is a diagram showing an example of a cross-sectional configuration of an imaging device according to an embodiment. Fig. 5A and Fig. 5B are diagrams showing an example of a planar configuration of a light guide section of an imaging device according to an embodiment. As shown in Fig. 4, the imaging device 1 has a configuration in which, for example, a light guide section 30, an insulating layer 20, a light receiving section 10, and a multilayer wiring layer 90 are stacked in the Z-axis direction.

[0033] The light receiving unit 10 has a semiconductor substrate 11 having a first surface 11S1 and a second surface 11S2 facing each other. The semiconductor substrate 11 is made of, for example, a silicon substrate. An insulating layer 20, a light guiding unit 30, etc. are provided on the first surface 11S1 side of the semiconductor substrate 11. A multilayer wiring layer 90 is provided on the second surface 11S2 side of the semiconductor substrate 11. The light guiding unit 30 is provided on the side where light from the optical system is incident, and the multilayer wiring layer 90 is provided on the side opposite to the side where the light is incident. The imaging device 1 is a so-called back-illuminated imaging device.

[0034] In the light receiving section 10, a plurality of photoelectric conversion sections 12 are provided along a first surface 11S1 and a second surface 11S2 of the semiconductor substrate 11. For example, the plurality of photoelectric conversion sections 12 are embedded in the semiconductor substrate 11. In addition, a separation section 50 is provided in the semiconductor substrate 11.

[0035] The separation unit 50 is provided between adjacent photoelectric conversion units 12 to separate the photoelectric conversion units 12. The separation unit 50 is provided on the semiconductor substrate 11 so as to surround the photoelectric conversion units 12. The separation unit 50 has a trench (groove portion) provided at the boundary between adjacent pixels P (or photoelectric conversion units 12).

[0036] As an example, an insulating film, for example, a silicon oxide film, is provided in the trench of the isolation portion 50. Note that polysilicon, a metal material, or the like may be embedded in the trench of the isolation portion 50. Also, a gap (cavity) may be provided in the trench of the isolation portion 50. By providing the isolation portion 50, leakage of light to the surrounding pixels P is suppressed.

[0037] The multi-layer wiring layer 90 has a configuration in which, for example, a plurality of wirings are stacked with interlayer insulating layers (interlayer insulating films) between them. The wiring layers of the multi-layer wiring layer 90 are formed using, for example, aluminum (Al), copper (Cu), or the like. The wiring layers may be formed using polysilicon (Poly-Si). The interlayer insulating layers are formed, for example, using silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), or the like.

[0038] For example, the above-mentioned readout circuit 18 is provided on the semiconductor substrate 11 and the multilayer wiring layer 90. Note that the above-mentioned pixel driving unit 111, signal processing unit 112, control unit 113, processing unit 114, etc. may be formed on a substrate separate from the semiconductor substrate 11, or on the semiconductor substrate 11 and the multilayer wiring layer 90.

[0039] The insulating layer 20 is provided between a layer in which the light-guiding section 30 is provided and the light-receiving section 10. The insulating layer 20 has an insulating film 21 and an insulating film 22. The insulating film 21 is provided on the first surface 11S1 of the semiconductor substrate 11. The insulating film 22 is provided by being stacked on the insulating film 21 and is located on the insulating film 21.

[0040] The insulating layer 20 is formed using, for example, an oxide film, a nitride film, an oxynitride film, or the like. The insulating film 21 and the insulating film 22 of the insulating layer 20 may be made of silicon oxide (SiO), TEOS, silicon nitride (SiN), silicon oxynitride (SiON), or the like, or may be made of other insulating materials. The insulating layer 20 can also be called a planarizing layer (planarizing film). In the example shown in FIG. 4, a light shielding portion 55 is provided in the insulating film 22 of the insulating layer 20.

[0041] The light shielding portion 55 (light shielding film) is made of a material that blocks light, and is provided at the boundary between adjacent pixels P. The light shielding portion 55 is formed, for example, on the insulating film 21, and is located above the separation portion 50 in the example shown in FIG. 4. The light shielding portion 55 is made of, for example, a metal material that blocks light (aluminum (Al), tungsten (W), copper (Cu), etc.). The light shielding portion 55 is provided around the photoelectric conversion portion 12, and prevents light from leaking to surrounding pixels. The light shielding portion 55 may be made of a material that absorbs light.

[0042] The imaging device 1 may have a fixed charge film between the photoelectric conversion section 12 and the insulating layer 20. The fixed charge film is, for example, composed of an oxide film (such as a metal oxide film). The fixed charge film may be formed on the photoelectric conversion section 12 and between the photoelectric conversion section 12 and the separation section 50. The fixed charge film is, for example, a film having a negative fixed charge, and suppresses the generation of dark current at the interface of the semiconductor substrate 11.

[0043] 4, the imaging device 1 has an antireflection film 26 and a protective film 60. The antireflection film 26 is made of an insulating material such as silicon nitride (SiN) or silicon oxide (SiO). In the example shown in FIG. 4, the antireflection film 26 is provided on the insulating film 22 and reduces (suppresses) reflection. Note that the light guide section 30 or the insulating layer 20 may be configured to include the antireflection film 26.

[0044] 4, the protective film 60 is provided on the light guiding sections 30. The protective film 60 is a passivation film (protective layer) and is formed so as to entirely cover the multiple light guiding sections 30. The protective film 60 is made of, for example, an inorganic material. For example, the protective film 60 is made of a silicon oxide film, a silicon nitride film, or the like.

[0045] The light guiding unit 30 has structures 31 and is configured to guide incident light to the light receiving unit 10. Light from a subject to be measured is incident on the light guiding unit 30. The structures 31 are minute (micro) structures having a size equal to or smaller than a predetermined wavelength of the incident light. The structures 31 have a size equal to or smaller than the wavelength of visible light, for example. The structures 31 may have a size equal to or smaller than the wavelength of infrared light.

[0046] The light guiding section 30 has a plurality of media (a first member 41 and a second member 42 in FIG. 4) provided around the structures 31. The first member 41 and the second member 42 are provided so as to fill the spaces between adjacent structures 31. The first member 41 and the second member 42 are embedded between the plurality of structures 31. The first member 41 and the second member 42 are filling members, and are filled between the plurality of structures 31. The first member 41 and the second member 42 can also be referred to as a first filling member and a second filling member, respectively.

[0047] 4, the light guide unit 30 has an anti-reflection film 35. The anti-reflection film 35 is made of an insulating material such as silicon nitride (SiN) or silicon oxide (SiO). The anti-reflection film 35 is provided on the structure 31 to reduce (suppress) reflection.

[0048] The first member 41 and the second member 42 are made of different materials. In the present embodiment, the first member 41 is made of an inorganic material and is provided in contact with the structure 31. The second member 42 is made of an organic material and is provided on the first member 41. The first member 41 is formed so as to cover the structure 31 and the anti-reflection film 35, and the second member 42 is formed so as to cover the first member 41. The second member 42 is stacked on the first member 41 and in contact with the first member 41.

[0049] The light guide unit 30 is an optical element (optical member) that guides (propagates) light. The light guide unit 30 (light guide member) uses a plurality of structures 31, which are microstructures, to propagate light to the photoelectric conversion unit 12. The light guide unit 30 is provided for each pixel P or for each plurality of pixels P.

[0050] The structures 31 are, for example, pillar-shaped structures as shown in Fig. 4. As shown typically in Fig. 4, the multiple structures 31 are arranged side by side in the left-right direction (X-axis direction) of the page, sandwiching at least one of the first member 41 and the second member 42. In each pixel P of the imaging device 1, the multiple structures 31 can be arranged at intervals equal to or less than a predetermined wavelength of incident light, for example, equal to or less than the wavelength of visible light (or infrared light).

[0051] The structure 31 has a refractive index different from the refractive index of the surrounding medium. The structure 31 has a refractive index different from the refractive index of the first member 41 and the second member 42 which are media around the structure 31. The structure 31 has a refractive index higher than the refractive index of the surrounding medium, for example.

[0052] The structure 31 has, for example, a refractive index higher than the refractive index of the first member 41. The structure 31 also has a refractive index higher than the refractive index of the second member 42. The structure 31 can be made of a material having a refractive index higher than the refractive index of the first member 41 and the refractive index of the second member 42.

[0053] The first member 41 has a refractive index higher than that of the second member 42. The difference between the refractive index of the structure 31 and the refractive index of the first member 41 is, for example, 0.3 or more. The difference between the refractive index of the structure 31 and the refractive index of the second member 42 is also, for example, 0.3 or more.

[0054] As an example, the structure 31 is configured using titanium oxide. The structure 31 may be configured using a simple substance, an oxide, a nitride, an oxynitride, or a composite of titanium, hafnium, zirconium, tantalum, aluminum, niobium, indium, or the like. The structure 31 may also be formed using silicon oxide, silicon nitride, silicon nitride oxide, silicon carbide, silicon oxide carbide, or other silicon compounds.

[0055] The structure 31 may be made of amorphous silicon (a-Si), polysilicon, germanium (Ge), or the like. The structure 31 may also be made of an organic material such as siloxane. For example, the structure 31 may be made of a siloxane-based resin, a styrene-based resin, an acrylic-based resin, or the like. The structure 31 may be made of a material in which any of these resins contains fluorine. The structure 31 may be formed using a material in which any of these resins is filled with beads (filler) having a higher refractive index than the resin.

[0056] The material of the structure 31 can be selected depending on, for example, the refractive index difference with the surrounding medium, the wavelength range of the incident light to be measured, etc. For example, in the case of the imaging device 1 that guides infrared light, the structure 31 may be made of amorphous silicon (a-Si), polysilicon, germanium (Ge), etc.

[0057] As described above, the first member 41 is made of an inorganic material. The first member 41 is formed of an inorganic material such as an oxide, a nitride, or an oxynitride. The first member 41 is made of, for example, silicon oxide, silicon nitride, silicon nitride oxide, silicon carbide, or silicon oxide carbide. The first member 41 may be made of a metal compound such as titanium or hafnium depending on the refractive index difference with the structure 31, the wavelength range of the incident light to be measured, and the like.

[0058] As described above, the second member 42 is made of an organic material. The second member 42 is made of an organic substance such as siloxane. The second member 42 may be made of a siloxane-based resin, a styrene-based resin, an acrylic-based resin, or the like. The second member 42 may be made of a material in which any of these resins contains fluorine. The second member 42 may be formed of a material in which any of these resins is filled with beads having a higher refractive index than that of the resin.

[0059] The light guiding unit 30 can affect the wavefront by causing a phase delay in the incident light due to the difference between the refractive index of the structure 31 and the refractive index of the surrounding medium. The light guiding unit 30 can impart a phase delay to the incident light by, for example, the structure 31, the first member 41, and the second member 42, and adjust the propagation direction of the light.

[0060] The size, shape, refractive index, pitch (arrangement interval), and the like of each structure 31 are determined so that light of an arbitrary wavelength range included in the incident light travels in a desired direction. In the example shown in Fig. 4, the size, shape, refractive index, and pitch of each of the multiple structures 31, the refractive index of the first member 41, and the refractive index of the second member 42, and the like, can be adjusted. As an example, the multiple structures 31 can be arranged for each pixel P or for each plurality of pixels P, as in the example shown in Fig. 5A or 5B.

[0061] The light guide unit 30 is an optical element that utilizes metamaterial (metasurface) technology, and can also be said to be a light guide element capable of guiding light. The direction of light propagation by the light guide unit 30 can be adjusted by the materials (optical constants) of the structures 31, the first member 41, the second member 42, etc., the shape, height, pitch (arrangement interval) of the structures 31, etc.

[0062] Light from a subject is incident on the photoelectric conversion unit 12 of each pixel P via the light guiding unit 30. The photoelectric conversion unit 12 receives the light incident via the light guiding unit 30, performs photoelectric conversion, and can generate charges according to the amount of received light. In this way, the imaging device 1 can generate, for example, a visible image, an infrared image, etc., using a pixel signal obtained by photoelectric conversion by the photoelectric conversion unit 12. In the imaging device 1, the light guiding unit 30 can appropriately guide light to the photoelectric conversion unit 12, making it possible to suppress a decrease in sensitivity to incident light.

[0063] In this manner, in the present embodiment, the first member 41 and the second member 42 are provided so as to fill the spaces between adjacent structures 31. This makes it possible to suppress collapse of structures 31 and deterioration of the characteristics of light guiding section 30. Below, imaging device 1 according to the present embodiment will be further described in comparison with a comparative example.

[0064] The first comparative example is a case where the structures 31 of the imaging device 1 only have a filler made of an organic material. In the first comparative example, as shown in Figs. 6A and 6B, an organic filler is filled between adjacent structures 31. In this case, as shown in Fig. 6A, it is considered that water is likely to accumulate between the columnar structures 31 due to moisture absorption. In addition, as shown in Fig. 6B, the columnar structures 31 may tilt due to thermal expansion of the organic material.

[0065] In this embodiment, as described above, the first member 41 made of an inorganic material is provided in contact with the structures 31, and the second member 42 made of an organic material is provided around the first member 41. By embedding the first member 41, which is a film made of an inorganic material, between adjacent structures 31, it is possible to prevent water from entering and accumulating between the structures 31, as shown typically in Fig. 7A. Furthermore, by providing the first member 41 in contact with the structures 31, it is possible to increase the strength of the structures 31, as shown typically in Fig. 7B, and it becomes possible to prevent the structures 31 from collapsing due to thermal expansion.

[0066] The second comparative example is a case where the structure 31 of the imaging device 1 has only a filler member made of an inorganic material. In the case of the second comparative example, as shown in FIG. 8, when the imaging device 1 is transferred as a semiconductor chip using a collet 200, a large pressure is generated by the hard inorganic filler, and there is a risk that the imaging device 1 may be scratched or cracked.

[0067] 9, in the present embodiment, a first member 41 made of an inorganic material and a second member 42 made of an organic material are provided around the structure 31 in the pixel section 100 and in a region outside the pixel section 100. When the imaging device 1 is transferred as a semiconductor chip using the collet 200, the second member 42 made of an organic material serves as a buffer layer, making it possible to prevent the imaging device 1 from being scratched or cracked.

[0068] Fig. 10 is a diagram for explaining a configuration example of a light guiding section of an imaging device according to an embodiment. Fig. 10 shows a configuration example of light guiding section 30 in the case of guiding light with a wavelength of 940 nm. Structure 31 is made of amorphous silicon (a-Si). Structure 31 has a thickness (height) h1 of 720 nm to 880 nm. Antireflection film 35 is made of a SiN film. Antireflection film 35 has a thickness (film thickness) h2 of 90 nm to 110 nm.

[0069] The first member 41 is made of a SiO film. The thickness h3 of the portion of the first member 41 on the antireflection film 35 is 135 nm to 165 nm. The second member 42 is made of a fluorine-containing siloxane resin. The thickness h4 of the portion of the second member 42 on the first member 41 is 80 nm to 100 nm. The protective film 60 is made of a SiO film. The thickness h5 of the protective film 60 is 145 nm to 180 nm.

[0070] In this manner, in the present embodiment, the first member 41 made of an inorganic material and the second member 42 made of an organic material are combined and arranged around the light-guiding section 30, thereby making it possible to reduce reflection in the structure 31. In the case of the example shown in Fig. 10, for example, the reflectance for incident light with a wavelength of 940 nm is about 16%.

[0071] 11A to 11F are diagrams showing an example of a manufacturing method of an imaging device according to an embodiment. First, as shown in Fig. 11A, an anti-reflection film 26 and the like are formed on a semiconductor substrate 11 on which elements such as a photoelectric conversion section 12 are formed, and then an a-Si film 71 (amorphous silicon film) is formed on the anti-reflection film 26. Then, as shown in Fig. 11B, a SiN film is formed as an anti-reflection film 35 on the a-Si film 71.

[0072] 11C, after forming a SiO film as the first member 41, a resist film 81 is formed by lithography and etching. Then, as shown in FIG. 11D, the first member 41, the anti-reflection film 35, and the a-Si film 71 are dry-etched or wet-etched. As a result, an excess portion of the a-Si film 71 is removed, and the structure 31 is formed.

[0073] Next, as shown in Fig. 11E, a SiO film is formed by ALD (Atomic Layer Deposition) to form a first member 41. Then, as shown in Fig. 11F, a resin material is applied to form a second member 42. Then, a protective film 60 is formed on the second member 42. By the manufacturing method described above, the imaging device 1 shown in Fig. 4 etc. can be manufactured.

[0074] 12A to 12J are diagrams showing another example of a method for manufacturing an imaging device according to an embodiment. Fig. 12A to 12J show a manufacturing process of light guiding section 30. First, as shown in Fig. 12A, a transparent inorganic filler member 72 is formed on antireflection film 26 as a material for first member 41.

[0075] 12B, a resist film 82 is formed by lithography and etching. Then, as shown in FIG 12C, the inorganic filling member 72 is selectively removed by etching to form the first member 41.

[0076] Next, as shown in Fig. 12D, a pillar material is deposited, and then CMP or etching is performed as shown in Fig. 12E to form a structure 31. Also, as shown in Fig. 12F, an anti-reflection film 35 is deposited. Then, as shown in Fig. 12G, a resist film 83 is formed on the anti-reflection film 35 by lithography and etching.

[0077] Next, as shown in Fig. 12H, the anti-reflection film 35 is selectively removed by etching. Furthermore, as shown in Fig. 12I, a first member 41 is formed. Then, as shown in Fig. 12J, a second member 42 is formed. The imaging device 1 shown in Fig. 4 etc. can be manufactured by the manufacturing method as described above. Note that the manufacturing method described above is merely one example, and other manufacturing methods may be adopted.

[0078] [Actions and Effects] The light detection device of this embodiment includes a light guiding section (light guiding section 30) having a plurality of structures (structures 31), each having a size equal to or smaller than the wavelength of incident light, a first medium (first member 41) and a second medium (second member 42) arranged to fill the spaces between adjacent structures and each having a refractive index different from the refractive index of the structures, and a photoelectric conversion section (photoelectric conversion section 12) that photoelectrically converts light incident through the light guiding section.

[0079] In the light detection device (imaging device 1) according to this embodiment, the first member 41 and the second member 42 are provided so as to fill the spaces between adjacent structures. This makes it possible to suppress the collapse of the structures 31 and the deterioration of the characteristics of the light guiding section 30. It is possible to realize a light detection device capable of suppressing deterioration in quality.

[0080] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0081] <2. Modifications> (2-1. Variation 1) Fig. 13 is a diagram showing a configuration example of a light guiding section of an imaging device according to Modification 1 of the present disclosure. The light guiding section 30 may be configured using a plurality of first members 41 and a plurality of second members 42. For example, as in the example shown in Fig. 13, the light guiding section 30 may have a first member 41a and a first member 41b. The first member 41a and the first member 41b are each configured using an inorganic material, for example. The first member 41a and the first member 41b may be configured using different inorganic materials.

[0082] 13, the first member 41a is provided in contact with the structure 31. The first member 41b is provided on the first member 41a and is formed so as to cover the first member 41a. The second member 42 is stacked on the first member 41b and in contact with the first member 41b. In the case of this modification, the same effects as those of the above-mentioned embodiment can be obtained.

[0083] (2-2. Variation 2) Fig. 14 is a diagram showing a configuration example of a light guiding section of an imaging device according to Modification 2. As in the example shown in Fig. 14, the light guiding section 30 may have a second member 42a and a second member 42b. For example, the second member 42a and the second member 42b are each made of an organic material. The second member 42a and the second member 42b may be made of different organic materials.

[0084] 14, the second member 42a is provided in contact with the first member 41. The second member 42b is provided on the second member 42a and is formed so as to cover the second member 42a. In the case of this modified example, the same effects as those of the above-mentioned embodiment can be obtained.

[0085] (2-3. Variation 3) Fig. 15 is a diagram showing a configuration example of an imaging device according to Modification 3. As shown typically in Fig. 15, the photoelectric conversion unit 12 of the imaging device 1 may have an uneven shape, for example a quadrangular pyramid shape, on the first surface 11S1 side of the semiconductor substrate 11. That is, the imaging device 1 has a photoelectric conversion unit 12 with an inverted quadrangular pyramid groove structure on the light receiving surface side, and has a moth-eye structure.

[0086] The imaging device 1 according to this modification has a structure in which fine projections and recesses are formed in the region above the photoelectric conversion unit 12 of each pixel P. The photoelectric conversion unit 12 includes a plurality of recesses and projections, and can be said to have an uneven structure. In this case, light can be efficiently guided to the photoelectric conversion unit 12, and the sensitivity to incident light can be improved.

[0087] (2-4. Variation 4) In the above-described embodiment and modified example, a configuration example of the light guiding section 30 having the structures 31 has been described. The shape of the structures 31 of the light guiding section 30 is not limited to the above-described example. The shape of the structures 31 can be appropriately changed, and may be, for example, a quadrangle in a plan view. Furthermore, the shape of the structures 31 may be a polygon, an ellipse, a cross, or another shape.

[0088] (2-5. Variation 5) The imaging device 1 may have a lens unit and a color filter. The lens unit is provided, for example, on the light guide unit 30, and guides light incident from above to the light guide unit 30. The color filter is configured to selectively transmit light of a specific wavelength range among the incident light. The color filter is provided, for example, between the light guide unit 30 and the photoelectric conversion unit 12. The color filter is, for example, a primary color (RGB) color filter. Also, complementary color filters such as Cy (cyan), Mg (magenta), and Ye (yellow) may be arranged.

[0089] (2-6. Variation 6) The light guiding unit 30, which is an optical element, may be configured as a spectroscopic unit (spectroscopic element) capable of dispersing light, depending on the design of the structure 31. In this case, the light guiding unit 30 may also be called a splitter (color splitter). For example, the light guiding unit 30 may be configured as a lens unit that collects light. The light guiding unit 30 may also be configured as a filter unit that selectively transmits light of a specific wavelength range from among the incident light. The light detection device and optical element (light guiding unit 30) according to the present disclosure can be applied to various devices.

[0090] <3. Application Examples> The imaging device 1 and the like can be applied to any type of electronic device equipped with an imaging function, for example, a camera system such as a digital still camera or a video camera, a mobile phone equipped with an imaging function, etc. Fig. 16 shows a schematic configuration of an electronic device 1000.

[0091] The electronic device 1000 includes, for example, a lens group 1001, an imaging device 1, a DSP (Digital Signal Processor) circuit 1002, a frame memory 1003, a display unit 1004, a recording unit 1005, an operation unit 1006, and a power supply unit 1007, which are interconnected via a bus line 1008.

[0092] The lens group 1001 captures incident light (image light) from a subject and forms an image on the imaging surface of the imaging device 1. The imaging device 1 converts the amount of incident light formed on the imaging surface by the lens group 1001 into an electrical signal on a pixel-by-pixel basis and supplies the signal to the DSP circuit 1002 as a pixel signal.

[0093] The DSP circuit 1002 is a signal processing circuit that processes a signal supplied from the imaging device 1. The DSP circuit 1002 outputs image data obtained by processing the signal from the imaging device 1. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 on a frame-by-frame basis.

[0094] The display unit 1004 is, for example, a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and records image data of moving images or still images captured by the imaging device 1 in a recording medium such as a semiconductor memory or a hard disk.

[0095] The operation unit 1006 outputs operation signals for various functions of the electronic device 1000 in accordance with operations by a user. The power supply unit 1007 appropriately supplies various types of power to the DSP circuit 1002, the frame memory 1003, the display unit 1004, the recording unit 1005, and the operation unit 1006 as operating power sources to these power sources.

[0096] <4. Application Examples> (Example of application to moving objects) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.

[0097] FIG. 17 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0098] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 17, 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, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

[0099] 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.

[0100] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0101] 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 an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0102] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according 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.

[0103] 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.

[0104] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0105] 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 the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0106] 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-vehicle 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-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0107] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 17, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0108] FIG. 18 is a diagram showing an example of the installation position of the imaging unit 12031.

[0109] In FIG. 18, a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as an imaging unit 12031.

[0110] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The images of the front acquired by the imaging units 12101 and 12105 are mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0111] 18 shows an example of the imaging ranges of the imaging units 12101 to 12104. An 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 an imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0112] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0113] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0114] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects, such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, based on the 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. Then, the microcomputer 12051 determines a collision risk indicating the degree of danger of collision with each obstacle, and when the collision risk is equal to or exceeds a set value and there is a possibility of collision, 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.

[0115] At least one of the imaging 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 or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0116] An example of a mobile object control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the imaging unit 12031 among the configurations described above. Specifically, for example, the imaging device 1 or the like can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, a high-definition captured image can be obtained, and high-precision control using the captured image can be performed in the mobile object control system.

[0117] (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.

[0118] FIG. 19 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.

[0119] 19 shows a state in which an operator (doctor) 11131 is 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.

[0120] 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 illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0121] 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 observation target in 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.

[0122] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on 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 an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0123] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0124] 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.

[0125] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0126] 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 irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0127] 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 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0128] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0129] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0130] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0131] FIG. 20 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0132] 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 by a transmission cable 11400 so as to be able to communicate with each other.

[0133] 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 configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0134] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be one (so-called single-plate type) or multiple (so-called multi-plate type). When the imaging unit 11402 is composed of a multi-plate 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 the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (Dimensional) display. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is composed of a multi-plate type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0135] 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 behind the objective lens.

[0136] 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 appropriately adjusted.

[0137] The communication unit 11404 is configured by a communication device for transmitting and receiving various 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.

[0138] 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 capturing the image, and / or information specifying the magnification and focus of the captured image.

[0139] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an 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.

[0140] 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.

[0141] The communication unit 11411 is configured with 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.

[0142] 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.

[0143] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0144] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and 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.

[0145] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed 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 techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0146] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0147] Here, 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.

[0148] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. Of the configurations described above, the technology according to the present disclosure can be suitably applied to, for example, the imaging unit 11402 provided in the camera head 11102 of the endoscope 11100. By applying the technology according to the present disclosure to the imaging unit 11402, the sensitivity of the imaging unit 11402 can be increased, and a high-definition endoscope 11100 can be provided.

[0149] Although the present disclosure has been described above by way of the embodiment, modifications, application examples, and application examples, the present technology is not limited to the above-described embodiment, etc., and various modifications are possible. For example, although the above-described modifications have been described as modifications of the above-described embodiment, the configurations of the modifications can be appropriately combined.

[0150] In the above-mentioned embodiment, an imaging device is described as an example, but the light detection device of the present disclosure may be, for example, a device that receives incident light and converts the light into an electric charge. The output signal may be a signal of image information or a signal of distance measurement information. The light detection device (imaging device) may be applied to an image sensor, a distance measurement sensor, etc.

[0151] The light detection device according to the present disclosure may also be applied as a distance measurement sensor capable of measuring distances using a time-of-flight (TOF) method. The light detection device (imaging device) may also be applied as a sensor capable of detecting an event, for example, an event-driven sensor (also called an event vision sensor (EVS), an event driven sensor (EDS), a dynamic vision sensor (DVS), or the like).

[0152] The photodetector according to an embodiment of the present disclosure includes a plurality of structures each having a size equal to or smaller than the wavelength of incident light, a light guide having a first medium and a second medium each having a refractive index different from that of the structures and disposed so as to fill the spaces between adjacent structures, and a photoelectric conversion unit that photoelectrically converts the light incident through the light guide. This makes it possible to suppress the collapse of the structures and the deterioration of the characteristics of the light guide. It is possible to realize a photodetector that can suppress deterioration in quality.

[0153] The optical element according to an embodiment of the present disclosure includes a plurality of structures each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium each having a refractive index different from the refractive index of the structures and provided to fill the spaces between the adjacent structures. This makes it possible to suppress the collapse of the structures and the deterioration of the characteristics of the optical element. It is possible to realize an optical element capable of suppressing deterioration in quality.

[0154] In addition, the effects described in this specification are merely examples and are not limited to the description, and other effects may be obtained. In addition, the present disclosure may have the following configurations. (1) a light guide section including a plurality of structures each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium each having a refractive index different from the refractive index of the structures and provided so as to fill spaces between adjacent ones of the plurality of structures; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; A light detection device comprising: (2) the first medium is provided in contact with the structure and is made of an inorganic material; The second medium is provided so as to cover the first medium and is made of an organic material. The light detection device according to (1) above. (3) the first medium is provided so as to cover the plurality of structures; The second medium is provided so as to cover the first medium. The optical detection device according to (1) or (2). (4) The refractive index of the structure is higher than the refractive index of the first medium. The optical detection device according to any one of (1) to (3). (5) The difference between the refractive index of the structure and the refractive index of the first medium is 0.3 or more. The photodetector according to any one of (1) to (4). (6) The refractive index of the first medium is higher than the refractive index of the second medium. The optical detection device according to any one of (1) to (5). (7) The light guide section has a plurality of the structures having different sizes, shapes, or arrangement pitches. The photodetector according to any one of (1) to (6). (8) The light guide portion includes a plurality of the structures each having a columnar shape. The optical detection device according to any one of (1) to (7). (9) The structure has a size equal to or smaller than the wavelength of visible light or equal to or smaller than the wavelength of infrared light. The photodetector according to any one of (1) to (8). (10) A plurality of structures each having a size equal to or smaller than the wavelength of the incident light; a first medium and a second medium, each of which has a refractive index different from that of the structures, being provided so as to fill the spaces between the adjacent structures; An optical element comprising: (11) the first medium is provided in contact with the structure and is made of an inorganic material; The second medium is provided so as to cover the first medium and is made of an organic material. The optical element according to (10) above. (12) the first medium is provided so as to cover the plurality of structures; The second medium is provided so as to cover the first medium. The optical element according to (10) or (11) above. (13) The refractive index of the structure is higher than the refractive index of the first medium. The optical element according to any one of (10) to (12) above. (14) The difference between the refractive index of the structure and the refractive index of the first medium is 0.3 or more. The optical element according to any one of (10) to (13) above. (15) The refractive index of the first medium is higher than the refractive index of the second medium. The optical element according to any one of (10) to (14). (16) The plurality of structures includes a plurality of structures having different sizes, shapes, or arrangement pitches. The optical element according to any one of (10) to (15) above. (17) The plurality of structures includes structures having a columnar shape. The optical element according to any one of (10) to (16) above. (18) The structure has a size equal to or smaller than the wavelength of visible light or equal to or smaller than the wavelength of infrared light. The optical element according to any one of (10) to (17) above. (19) An optical system; a light detection device that receives light transmitted through the optical system; Equipped with The light detection device includes: a light guide section including a plurality of structures each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium each having a refractive index different from the refractive index of the structures and provided so as to fill spaces between adjacent ones of the plurality of structures; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; have electronic equipment. [Explanation of symbols]

[0155] 1...imaging device, 10...light receiving section, 12...photoelectric conversion section, 20...insulating layer, 21, 22...insulating films, 26, 35...anti-reflection films, 30...light guiding section, 31...structure, 41...first member, 42...second member.

Claims

1. a light guide section including a plurality of structures each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium each having a refractive index different from the refractive index of the structures and provided so as to fill spaces between adjacent ones of the plurality of structures; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; A light detection device comprising:

2. the first medium is provided in contact with the structure and is made of an inorganic material; The second medium is provided so as to cover the first medium and is made of an organic material.

2. The optical detection device according to claim 1.

3. the first medium is provided so as to cover the plurality of structures; The second medium is provided so as to cover the first medium.

3. The optical detection device according to claim 2.

4. The refractive index of the structure is higher than the refractive index of the first medium.

3. The optical detection device according to claim 2.

5. The difference between the refractive index of the structure and the refractive index of the first medium is 0.3 or more.

5. The optical detection device according to claim 4.

6. The refractive index of the first medium is higher than the refractive index of the second medium.

3. The optical detection device according to claim 2.

7. The light guide section has a plurality of the structures having different sizes, shapes, or arrangement pitches.

2. The optical detection device according to claim 1.

8. The light guide portion includes a plurality of the structures each having a columnar shape.

2. The optical detection device according to claim 1.

9. The structure has a size equal to or smaller than the wavelength of visible light or equal to or smaller than the wavelength of infrared light.

2. The optical detection device according to claim 1.

10. A plurality of structures each having a size equal to or smaller than the wavelength of the incident light; a first medium and a second medium, each of which has a refractive index different from that of the structures, and which are provided so as to fill the spaces between the adjacent structures; An optical element comprising:

11. the first medium is provided in contact with the structure and is made of an inorganic material; The second medium is provided so as to cover the first medium and is made of an organic material. The optical element according to claim 10.

12. the first medium is provided so as to cover the plurality of structures; The second medium is provided so as to cover the first medium. The optical element according to claim 11.

13. The refractive index of the structure is higher than the refractive index of the first medium. The optical element according to claim 11.

14. The difference between the refractive index of the structure and the refractive index of the first medium is 0.3 or more. The optical element according to claim 13.

15. The refractive index of the first medium is higher than the refractive index of the second medium. The optical element according to claim 11.

16. The plurality of structures includes a plurality of structures having different sizes, shapes, or arrangement pitches. The optical element according to claim 10.

17. The plurality of structures includes structures having a columnar shape. The optical element according to claim 10.

18. The structure has a size equal to or smaller than the wavelength of visible light or equal to or smaller than the wavelength of infrared light. The optical element according to claim 10.

19. An optical system; a light detection device that receives light transmitted through the optical system; Equipped with The light detection device includes: a light guide section including a plurality of structures each having a size equal to or smaller than the wavelength of incident light, and a first medium and a second medium each having a refractive index different from the refractive index of the structures and provided so as to fill spaces between adjacent ones of the plurality of structures; a photoelectric conversion unit that photoelectrically converts light incident via the light guiding unit; have electronic equipment.

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