Photodetection apparatus, optical element, and electronic device

Abstract

A photodetection apparatus according to one embodiment of the present disclosure comprises: a first structure that has a spherical or ellipsoidal shape; a first light guide member that includes a filler member provided around the first structure and having a refractive index different from the refractive index of the first structure; and a first photoelectric conversion element that performs photoelectric conversion of light entering through the first light guide member.

Description

Photodetector, optical element, and electronic device

[0001] The present disclosure relates to a light detection device, an optical element, and an electronic device.

[0002] A meta-optical element has been proposed that includes a plurality of nanostructures having a cylindrical shape and a surrounding substance having a refractive index different from that of the nanostructures (Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-140152

[0004] In a light detecting device, it is desirable to improve the characteristics for obliquely incident light.

[0005] It is desirable to provide a photodetector that can improve the characteristics for obliquely incident light.

[0006] A photodetector according to an embodiment of the present disclosure includes a first structure having a spherical or ellipsoidal shape, a first light guide member including a filler member disposed around the first structure and having a refractive index different from that of the first structure, and a first photoelectric conversion element configured to photoelectrically convert light incident through the first light guide member. An optical element according to an embodiment of the present disclosure includes a plurality of first structures having a spherical or ellipsoidal shape, and a filler member disposed between adjacent first structures and having a refractive index different from that of the first structures. An electronic device according to an embodiment of the present disclosure includes an optical system and a photodetector configured to receive light transmitted through the optical system. The photodetector includes a first structure having a spherical or ellipsoidal shape, a first light guide member including a filler member disposed around the first structure and having a refractive index different from that of the first structure, and a first photoelectric conversion element configured to photoelectrically convert light incident through the first light guide member.

[0007] FIG. 1 is a block diagram showing an example of a schematic configuration of an imaging device which is an example of a photodetector according to a first embodiment of the present disclosure. FIG. 2 is a diagram showing an example of a pixel unit of the imaging device according to the first embodiment of the present disclosure. FIG. 3 is a diagram for explaining an example of a circuit configuration of a pixel of the imaging device according to the first embodiment of the present disclosure. FIG. 4 is a diagram showing an example of a planar configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 5 is a diagram showing an example of a planar configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 6 is a diagram showing an example of a cross-sectional configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 7 is a diagram showing another example of a cross-sectional configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 8 is a diagram showing another example of a cross-sectional configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 9A is a diagram showing an example of a cross-sectional configuration of the imaging device according to the first embodiment of the present disclosure at different image height positions. FIG. 9B is a diagram showing an example of a cross-sectional configuration of the imaging device according to the first embodiment of the present disclosure at different image height positions. FIG. 10A is a diagram for explaining an example of a configuration of the imaging device according to the first embodiment of the present disclosure. FIG. 10B is a diagram for describing an example configuration of an imaging device according to the first embodiment of the present disclosure. FIG. 10C is a diagram for describing an example configuration of an imaging device according to the first embodiment of the present disclosure. FIG. 11A is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11B is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11C is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11D is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11E is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11F is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11G is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11H is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure.FIG. 11I is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 11J is a diagram for describing an example of a method for manufacturing a light guiding section of an imaging device according to the first embodiment of the present disclosure. FIG. 12A is a diagram for describing an example of a configuration of an imaging device according to Modification 1 of the present disclosure. FIG. 12B is a diagram for describing an example of a configuration of an imaging device according to Modification 1 of the present disclosure. FIG. 13A is a diagram for describing another example of a configuration of an imaging device according to Modification 1 of the present disclosure. FIG. 13B is a diagram for describing another example of a configuration of an imaging device according to Modification 1 of the present disclosure. FIG. 14 is a diagram for describing an example of a configuration of an imaging device according to Modification 2 of the present disclosure. FIG. 15A is a diagram for describing an example of a configuration of an imaging device according to Modification 3 of the present disclosure. FIG. 15B is a diagram for describing an example of a configuration of an imaging device according to Modification 3 of the present disclosure. FIG. 16A is a diagram for describing an example of a configuration of an imaging device according to Modification 4 of the present disclosure. FIG. 16B is a diagram for describing an example of a configuration of an imaging device according to Modification 4 of the present disclosure. FIG. 17A is a diagram illustrating another example configuration of an imaging device according to Modification 4 of the present disclosure. FIG. 17B is a diagram illustrating another example configuration of an imaging device according to Modification 4 of the present disclosure. FIG. 18A is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. FIG. 18B is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. FIG. 18C is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. FIG. 18D is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. FIG. 19 is a diagram illustrating an example planar configuration of an imaging device according to a second embodiment of the present disclosure. FIG. 20 is a diagram illustrating an example cross-sectional configuration of an imaging device according to the second embodiment of the present disclosure. FIG. 21 is a diagram illustrating an example configuration of an imaging device according to the second embodiment of the present disclosure. FIG. 22 is a diagram illustrating an example configuration of an imaging device according to Modification 7 of the present disclosure. FIG. 23 is a diagram illustrating an example configuration of an imaging device according to Modification 8 of the present disclosure. FIG. 24A is a diagram illustrating an example configuration of an imaging device according to Modification 9 of the present disclosure. Fig. 24B is a diagram for explaining a configuration example of an imaging device according to Modification 9 of the present disclosure. Fig. 25A is a diagram for explaining a configuration example of an imaging device according to Modification 10 of the present disclosure.FIG. 25B is a diagram for explaining a configuration example of an imaging device according to Modification 10 of the present disclosure. FIG. 26A is a diagram for explaining another configuration example of an imaging device according to Modification 10 of the present disclosure. FIG. 26B is a diagram for explaining another configuration example of an imaging device according to Modification 10 of the present disclosure. FIG. 27 is a diagram for explaining a configuration example of an imaging device according to Modification 11 of the present disclosure. FIG. 28 is a diagram for explaining a configuration example of an imaging device according to Modification 12 of the present disclosure. FIG. 29 is a diagram for explaining a configuration example of an optical element according to a third embodiment of the present disclosure. FIG. 30 is a diagram for explaining a configuration example of an optical element according to the third embodiment of the present disclosure. FIG. 31 is a block diagram showing an example of the configuration of an electronic device having an imaging device. FIG. 32 is a block diagram showing an example of a schematic configuration of a vehicle control system. FIG. 33 is an explanatory diagram showing an example of installation positions of an outside vehicle information detection unit and an imaging unit. FIG. 34 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. FIG. 35 is a block diagram showing an example of the functional configuration of a camera head and a CCU.

[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. First embodiment 2. Second embodiment 3. Third embodiment 4. Application example 5. Application example

[0009] 1. First 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 a first embodiment of the present disclosure. Fig. 2 is a diagram showing an example of a pixel unit of the imaging device according to the first embodiment. The photodetection device is a device capable of detecting incident light. The imaging device 1 which is a photodetection device has a plurality of pixels P each having a photoelectric conversion unit (photoelectric conversion element), and is configured to photoelectrically convert incident light to generate a signal.

[0010] The imaging device 1 can generate a signal by receiving light that has passed through an optical system (not shown) including an optical lens. The imaging device 1 is configured, for example, using a semiconductor substrate (e.g., a silicon substrate) on which a plurality of pixels P are provided. The photoelectric conversion unit of each pixel P of the imaging device 1 is, for example, a photodiode (PD) that is configured to be able to photoelectrically convert light.

[0011] 1 and 2, the imaging device 1 has, as an imaging area, a region (pixel section 100) in which a plurality of pixels P are arranged two-dimensionally in a matrix. The pixel section 100 of the imaging device 1 is a pixel array in which a plurality of pixels P are arranged, and can also be referred to as a light receiving region. The photoelectric conversion section of each pixel P can also be referred to as a photoelectric conversion region.

[0012] The imaging device 1 captures incident light (image light) from a subject to be measured via an optical system including an optical lens. The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can generate pixel signals by photoelectrically converting the received light (e.g., visible light, infrared light, etc.). The imaging device 1, which is a photodetector, is a device that can receive incident light and generate a signal, and can also be called a light-receiving device.

[0013] The imaging device 1 (photodetector) may be configured as an image sensor, for example. The imaging device 1 may be, for example, a complementary metal oxide semiconductor (CMOS) image sensor. The imaging device 1 may have a structure (a stacked structure) formed by stacking multiple semiconductor layers. The imaging device 1 may be used in various electronic devices, such as digital still cameras, video cameras, and mobile phones.

[0014] 2, the incident direction of light from the subject is defined as the Z-axis direction, the left-right direction on the paper surface perpendicular to the Z-axis direction is defined as the X-axis direction, and the up-down direction on the paper surface perpendicular to the Z-axis and X-axis directions is defined as the Y-axis direction. In the following figures, directions may be indicated based on the direction of the arrow in FIG. 2.

[0015] 1 , the imaging device 1 includes a pixel unit 100, a pixel control unit 111, a signal processing unit 112, a control unit 113, and a processing unit 114. The imaging device 1 is also provided with, for example, a plurality of control lines Lread and a plurality of signal lines VSL. The control lines Lread are signal lines capable of transmitting signals for controlling the pixels P, and are connected to the pixel control unit 111 and the pixels P of the pixel unit 100.

[0016] 1 , in the pixel unit 100, a plurality of control lines Lread are wired for each pixel row made up of a plurality of pixels P arranged in the horizontal direction (row direction). The control lines Lread are configured to transmit control signals for reading out signals from the pixels P. The control lines Lread can also be considered drive lines (pixel drive lines) that transmit signals for driving the pixels P.

[0017] The signal line VSL is a signal line capable of transmitting a signal from the pixel P, and is connected to the pixel P of the pixel unit 100 and the signal processing unit 112. In the pixel unit 100, for example, one or more signal lines VSL are wired for each pixel column formed by a plurality of pixels P aligned in the vertical direction (column direction).

[0018] The signal line VSL is configured to be able to transmit signals output from the pixels P. In the imaging device 1, multiple signal lines VSL may be provided for one pixel column. The imaging device 1 can have multiple signal lines VSL for each pixel column.

[0019] The pixel control unit 111 is configured to be able to control each pixel P of the pixel unit 100. The pixel control unit 111 is a control circuit and is configured by a plurality of circuits including, for example, a buffer, a shift register, an address decoder, etc. The pixel control unit 111 generates a signal for controlling the pixel P and outputs it to each pixel P of the pixel unit 100 via a control line Lread. The pixel control unit 111 is controlled by the control unit 113 and controls the pixels P of the pixel unit 100.

[0020] The pixel control unit 111 generates signals for controlling the pixels P, such as signals for controlling the transfer transistors, selection transistors, and reset transistors of the pixels P, and supplies these signals to each pixel P via a control line Lread. The pixel control unit 111 can control the reading of pixel signals from each pixel P. The pixel control unit 111 can also be referred to as a pixel driving unit configured to be able to drive each pixel P. The pixel control unit 111 and the control unit 113 can also be referred to collectively as a pixel control unit.

[0021] The signal processing unit 112 is configured to be able to perform signal processing of input pixel signals. The signal processing unit 112 is a signal processing circuit and includes, for example, a load circuit, an AD (Analog-Digital) conversion circuit, a horizontal selection switch, etc. The load circuit is, for example, configured by a current source capable of supplying current to the amplification transistor of the pixel P. The load circuit, together with the amplification transistor of the pixel P, forms, for example, a source follower circuit.

[0022] The signal processing unit 112 may have an amplifier circuit configured to amplify signals read out from the pixels P via the signal lines VSL. A load circuit, an amplifier circuit, an AD conversion circuit, etc. are provided for each of the multiple signal lines VSL, for example. A load circuit, an amplifier circuit, an AD conversion circuit, etc. may be provided for each pixel column of the pixel unit 100.

[0023] The signals output from each pixel P selected and scanned by the pixel control unit 111 are input to the signal processing unit 112 via signal lines VSL. The signal processing unit 112 can perform signal processing such as AD conversion of the signals from the pixel P and CDS (Correlated Double Sampling). The signals from each pixel P transmitted through each of the signal lines VSL are subjected to signal processing by the signal processing unit 112 and output to the processing unit 114.

[0024] The processing unit 114 is configured to be able to perform signal processing on the input signal. The processing unit 114 is a processing circuit, and 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, gradation correction processing, etc.

[0025] 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, etc., and can also output data such as internal information of the imaging device 1. The control unit 113 is a control circuit, and has, for example, a timing generator configured to be able to generate various timing signals.

[0026] The control unit 113 controls the driving of the pixel control unit 111, the signal processing unit 112, etc. based on various timing signals (pulse signals, clock signals, etc.) generated by the timing generator. The pixel control unit 111, the signal processing unit 112, the control unit 113, the processing unit 114, etc. may be provided on a single semiconductor substrate, or may be provided separately on multiple semiconductor substrates. The imaging device 1 may have a stacked structure formed by stacking multiple substrates. Some or all of the signal processing unit 112, the control unit 113, and the processing unit 114 may be configured integrally.

[0027] 3 is a diagram illustrating an example of the circuit configuration of a pixel of the imaging device according to the first embodiment. The pixel P includes a photoelectric conversion unit 12 (photoelectric conversion element) and a readout circuit 20. The photoelectric conversion unit 12 is configured to receive light and generate a signal. The readout circuit 20 is configured to be able to output a signal based on charges photoelectrically converted. The readout circuit 20 can read out a pixel signal based on the charges photoelectrically converted by the photoelectric conversion unit 12.

[0028] The photoelectric conversion unit 12 is a light receiving unit (light receiving element) configured to be able to generate electric charges by photoelectric conversion. In the example shown in Fig. 3, the photoelectric conversion unit 12 is a photodiode (PD) that converts incident light into electric charges. The photoelectric conversion unit 12 can perform photoelectric conversion to generate electric charges according to the amount of received light.

[0029] The read circuit 20 includes, for example, a transistor TRG, a floating diffusion FD, a transistor AMP, a transistor SEL, and a transistor RST. The transistors TRG, AMP, SEL, and RST are MOS transistors (MOSFETs) each having a gate, a source, and a drain terminal.

[0030] 3, the transistor TRG, the transistor AMP, the transistor SEL, and the transistor RST are each configured as an NMOS transistor. Note that the transistor of the pixel P may also be configured as a PMOS transistor.

[0031] The transistor TRG is a transfer transistor and is configured to be able to transfer charges photoelectrically converted in the photoelectric conversion unit 12 to the floating diffusion FD. The transistor TRG is controlled by a signal STRG to electrically connect or disconnect the photoelectric conversion unit 12 and the floating diffusion FD. The transistor TRG can transfer charges photoelectrically converted and accumulated in the photoelectric conversion unit 12 to the floating diffusion FD.

[0032] The floating diffusion FD is an accumulation unit configured to be able to accumulate transferred charges. The floating diffusion FD can accumulate charges photoelectrically converted by the photoelectric conversion unit 12. The floating diffusion FD can also be considered a holding unit capable of holding the transferred charges. The floating diffusion FD accumulates the transferred charges and converts them into a voltage according to the capacitance of the floating diffusion FD.

[0033] The transistor AMP is configured to generate and output a signal based on the charge accumulated in the floating diffusion FD. The transistor AMP is an amplifying transistor and can generate and output a signal based on the charge converted by the photoelectric conversion unit 12.

[0034] The gate of the transistor AMP is electrically connected to the floating diffusion FD, and the voltage converted by the floating diffusion FD is input to the gate of the transistor AMP. In the example shown in Figure 3, the drain of the transistor AMP is connected to a power supply line through which a power supply voltage VDD is supplied.

[0035] The source of the transistor AMP is connected to a signal line VSL via a transistor SEL. The transistor AMP is configured to generate a signal based on the charge accumulated in the floating diffusion FD, i.e., a signal based on the voltage of the floating diffusion FD, and output the signal to the signal line VSL.

[0036] The transistor SEL is configured to be able to control the output of a pixel signal. The transistor SEL is electrically connected in series to the transistor AMP, for example, as in the example shown in Figure 3. The transistor SEL is controlled by a signal SSEL and is configured to be able to output a signal from the transistor AMP to a signal line VSL. The transistor SEL is a selection transistor and can control the output timing of the pixel signal.

[0037] The transistor SEL is configured to be able to output a signal based on the charge converted by the photoelectric conversion unit 12. The transistor SEL can output a pixel signal of the pixel P to a signal line VSL. The transistor SEL may be provided between the power supply line to which the power supply voltage VDD is applied and the transistor AMP. The transistor SEL may also be omitted as necessary.

[0038] The transistor RST is configured to be able to reset the voltage of the floating diffusion FD. In the example shown in Fig. 3, the transistor RST is electrically connected to a power supply line to which a power supply voltage VDD is applied, and is configured to reset the charge of the pixel P. The transistor RST is a reset transistor.

[0039] The transistor RST is controlled by a signal SRST to reset the charge accumulated in the floating diffusion FD and reset the voltage of the floating diffusion FD. In the example shown in Figure 3, the transistor RST electrically connects the power supply line and the floating diffusion FD and can discharge the charge accumulated in the floating diffusion FD. The transistor RST can also discharge the charge accumulated in the photoelectric conversion unit 12 via the transistor TRG.

[0040] The pixel control unit 111 (see Figure 1) of the imaging device 1 supplies control signals to the gates of the transistors TRG, SEL, RST, etc. of each pixel P via the control line Lread described above, turning the transistors on (conducting state) or off (non-conducting state).

[0041] The multiple control lines Lread for each pixel row of the imaging device 1 include, for example, a wiring for transmitting a signal STRG that controls the transistor TRG, a wiring for transmitting a signal SSEL that controls the transistor SEL, and a wiring for transmitting a signal SRST that controls the transistor RST.

[0042] The readout circuit 20 may be configured to change the conversion efficiency (gain) when converting electric charge into voltage. For example, the readout circuit 20 may have a switching transistor used to set the conversion efficiency. As an example, the switching transistor is provided between the floating diffusion FD and the transistor RST.

[0043] In the readout circuit 20, when the switching transistor is turned on, the capacitance added to the floating diffusion FD of the pixel P increases, and the conversion efficiency is switched. The switching transistor can change the capacitance connected to the gate of the transistor AMP to change the conversion efficiency.

[0044] The transistors TRG, SEL, RST, and switching transistors are controlled to be turned on and off by a pixel control unit 111. The pixel control unit 111 controls the readout circuit 20 of each pixel P to output a pixel signal from each pixel P to a signal line VSL. The pixel control unit 111 can control the reading out of the pixel signal of each pixel P to the signal line VSL.

[0045] [Configuration of Image Capturing Device] Fig. 4 is a diagram showing an example of the planar configuration of the image capturing device according to the first embodiment. Fig. 4 shows an example of the arrangement of pixels P of the pixel unit 100 in the image capturing device 1. The pixel P of the image capturing device 1 has a filter 25 and a light guiding unit 50 (light guiding member) configured using a structure 41.

[0046] The filter 25 is configured to selectively transmit light in a specific wavelength range from the incident light. The filter 25 is an RGB color filter, a filter that transmits infrared light, etc. The filter 25 is provided above the photoelectric conversion unit 12, for example, for each pixel P or for each set of multiple pixels P.

[0047] The plurality of pixels P provided in the pixel section 100 of the imaging device 1 includes, for example, a pixel Pr (R pixel) provided with a filter 25 that transmits red (R) light, a pixel Pg (G pixel) provided with a filter 25 that transmits green (G) light, and a pixel Pb (B pixel) provided with a filter 25 that transmits blue (B) light. In the pixel section 100, the plurality of pixels Pr, the plurality of pixels Pg, and the plurality of pixels Pb are repeatedly arranged.

[0048] The pixels Pr, Pg, and Pb are arranged, for example, according to a Bayer array. The pixels Pr, Pg, and Pb can generate pixel signals of R, G, and B components, respectively. The imaging device 1 can obtain RGB pixel signals. Note that the arrangement of the pixels P is not limited to the example described above and can be set arbitrarily.

[0049] For example, the pixels Pr, Pg, and Pb may each be arranged in units of 2 x 2 pixels. As an example, four adjacent pixels Pr, four adjacent pixels Pg, and four adjacent pixels Pb may be arranged repeatedly in the pixel unit 100. It can also be said that the pixels Pr, Pg, and Pb are each periodically arranged in 2 rows x 2 columns.

[0050] The filter 25 provided in the pixel P of the pixel unit 100 is not limited to a primary color (RGB) color filter, but may be a complementary color filter such as Cy (cyan), Mg (magenta), or Ye (yellow). A filter corresponding to W (white), i.e., a filter that transmits light of the entire wavelength range of incident light, may also be provided. The filter 25 may also be a filter that transmits infrared light.

[0051] It should be noted that the filter 25 may be omitted as needed in the imaging device 1. For example, a pixel that receives white (W) light and performs photoelectric conversion may not need to have the filter 25. Also, for example, depending on the characteristics of the light guide section 50, some or all of the pixels P of the imaging device 1 may not need to have the filter 25.

[0052] The light guide unit 50 has a structure 41 that is a nanostructure, and is configured to guide incident light toward the photoelectric conversion unit 12. The light guide unit 50 is a light guide element (light guide member) that uses metamaterial (metasurface) technology. The structure 41 of the light guide unit 50 has, for example, a spherical shape. The structure 41 may also have an elliptical shape. The structure 41 may have, for example, a circular or elliptical planar shape.

[0053] 4, the light guide unit 50 (light guide member) has a plurality of structures 41 and a filling member 45 provided around the structures 41 (see also FIG. 6 described later). The structures 41 and the filling member 45 are made of materials having different refractive indices. In the imaging device 1, as in the example shown in FIG. 4, the light guide unit 50 can be provided for each pixel P or for each set of pixels P.

[0054] The propagation direction of light through the structures 41 of the light-guiding unit 50 can be adjusted by the material (refractive index), size, arrangement interval (pitch), etc. of the structures 41. For example, the material, size, arrangement number, etc. of the structures 41 are determined so that light in a wavelength band to be detected is focused onto the photoelectric conversion unit 12.

[0055] The plurality of structures 41 of the light-guiding unit 50 are arranged two-dimensionally in the X-axis direction and the Y-axis direction intersecting the X-axis direction, for example, as in the example shown in Fig. 4 or 5. The plurality of structures 41 may be arranged in a square array as in the example shown in Fig. 4, or may be arranged in a hexagonal close-packed array as in the example shown in Fig. 5. For example, the arrangement positions, arrangement intervals, etc. of the structures 41 can be adjusted to obtain desired optical characteristics.

[0056] Fig. 6 is a diagram showing an example of a cross-sectional configuration of the imaging device according to the first embodiment. As shown in Fig. 6, the imaging device 1 includes, for example, a light guide 50, an insulating layer 70, a filter 25, a semiconductor layer 10, and a multilayer wiring layer 90. The imaging device 1 has a configuration in which the light guide 50, the insulating layer 70, the filter 25, the semiconductor layer 10, and the multilayer wiring layer 90 are stacked in the Z-axis direction. Note that the hollow arrows in Fig. 6 schematically show incident light on the light guide 50 including the structure 41.

[0057] From the light incident side, there are provided a layer where the light guide section 50 is provided (optical layer 60 in FIG. 6 ), an insulating layer 70, a layer where the filter 25 is provided, a semiconductor layer 10, and a multilayer wiring layer 90. In the example shown in FIG. 6 , the optical layer 60 including the plurality of structures 41 is provided by being stacked on the insulating layer 70.

[0058] As shown in FIG. 6 , the semiconductor layer 10 has opposing surfaces 11S1 and 11S2. The surface 11S2 is the surface opposite to the surface 11S1. The surface 11S1 of the semiconductor layer 10 is a light-receiving surface (light incident surface). The surface 11S2 of the semiconductor layer 10 is an element formation surface on which elements such as transistors are formed. A gate electrode, a gate insulating film (e.g., a gate oxide film), etc. are provided on the surface 11S2 of the semiconductor layer 10.

[0059] The semiconductor layer 10 is composed of a semiconductor substrate, for example, a Si (silicon) substrate. The semiconductor layer 10 may be an SOI (silicon on insulator) substrate, a SiGe (silicon germanium) substrate, a SiC (silicon carbide) substrate, or the like. The semiconductor layer 10 may be composed of a III-V group compound semiconductor material, or may be formed using other semiconductor materials.

[0060] 6 , a filter 25, a light guiding unit 50, etc. are provided on the surface 11S1 side of the semiconductor layer 10. The light guiding unit 50, the filter 25, etc. are stacked on the semiconductor layer 10 in a thickness direction perpendicular to the surface 11S1 of the semiconductor layer 10. The photoelectric conversion unit 12 photoelectrically converts light incident via the light guiding unit 50, the insulating layer 70, and the filter 25.

[0061] A multilayer wiring layer 90 is provided on the surface 11S2 side of the semiconductor layer 10. An optical layer 60 including a light guide 50 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 backside illuminated imaging device.

[0062] In the semiconductor layer 10, a plurality of photoelectric conversion units 12 (photoelectric conversion elements) are provided along a surface 11S1 and a surface 11S2 of the semiconductor layer 10. For example, the plurality of photoelectric conversion units 12 are embedded in the semiconductor layer 10. The photoelectric conversion units 12 can also be referred to as a photoelectric conversion layer. The photoelectric conversion units 12 are provided between the surface 11S1 and the surface 11S2 of the semiconductor layer 10.

[0063] The multilayer wiring layer 90 is provided by being stacked on the semiconductor layer 10. The multilayer wiring layer 90 includes, for example, a conductor film and an insulating film, and has a plurality of wirings and vias (VIAs). The multilayer wiring layer 90 has a configuration in which a plurality of wirings are stacked via an insulating film serving as an interlayer insulating film (interlayer insulating layer). The multilayer wiring layer 90 includes, for example, two or more layers of wirings, or three or more layers of wirings.

[0064] The wiring of the multilayer wiring layer 90 is formed using a metal material such as aluminum (Al), tungsten (W), or copper (Cu). The wiring of the multilayer wiring layer 90 may be formed using polysilicon (Poly-Si) or other conductive materials. The interlayer insulating film is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), or the like.

[0065] The semiconductor layer 10 and the multilayer wiring layer 90 are provided with the above-described readout circuit 20 (see FIG. 3 ), for example, for each pixel P or for each set of pixels P. The pixel control unit 111, the signal processing unit 112, the control unit 113, the processing unit 114, etc. (see FIG. 1 ) may be provided on a substrate separate from the semiconductor layer 10, or on the semiconductor layer 10 and the multilayer wiring layer 90.

[0066] The insulating layer 70 is provided between the optical layer 60 in which the light guide section 50 is provided and the semiconductor layer 10. In the example shown in Fig. 6, the insulating layer 70 is provided by being stacked on the layer in which the filter 25 is provided. The insulating layer 70 is formed using an insulating film such as an oxide film, a nitride film, or an oxynitride film, for example.

[0067] The insulating layer 70 is formed using an insulating material such as silicon oxide (SiO), silicon nitride (SiN), or aluminum oxide (AlO). The insulating layer 70 may be made of a material with a low refractive index such as silicon oxide, or may be made of another material that transmits light in the wavelength range to be measured. The insulating layer 70 can also be called a planarizing layer (planarizing film).

[0068] 6, the imaging device 1 is also provided with a separation section 80. The separation section 80 is provided between adjacent photoelectric conversion sections 12 to separate the photoelectric conversion sections 12. At least a portion of the separation section 80 is provided at the boundary between adjacent pixels P (or photoelectric conversion sections 12). The separation section 80 is formed using, for example, a trench (groove section).

[0069] The separation portion 80 can be formed in the semiconductor layer 10 so as to surround the photoelectric conversion portion 12 of each pixel P. The separation portion 80 is provided so as to penetrate the semiconductor layer 10, for example, as in the example shown in Fig. 6. The separation portion 80 can also be called a pixel separation portion or a pixel separation wall.

[0070] An insulating film, such as a silicon oxide film, a silicon nitride film, or an aluminum oxide film, is provided inside the trench of the isolation portion 80. Polysilicon, a metal material, another insulating material, or the like may be buried in the trench of the isolation portion 80. The isolation portion 80 may be configured of a semiconductor region (a p-type semiconductor region or an n-type semiconductor region) formed by ion implantation.

[0071] The separation portion 80 may be formed using another insulating material having a low refractive index. A gap (cavity) may be provided within the trench of the separation portion 80. In the imaging device 1, the separation portion 80 is provided to prevent the charge photoelectrically converted in the photoelectric conversion portion 12 of the pixel P from leaking to the surrounding pixels P (or the photoelectric conversion portion 12). Furthermore, the separation portion 80 can prevent unnecessary light from leaking to the surrounding pixels P, thereby preventing color mixing, for example.

[0072] The imaging device 1 may have at least one of a fixed charge film and an anti-reflection film. The fixed charge film and the anti-reflection film are provided, for example, on the surface 11S1 side of the semiconductor layer 10. For example, the fixed charge film and the anti-reflection film are made of a metal compound (metal oxide, metal nitride, etc.), and can also be called a metal compound layer.

[0073] The fixed charge film and the anti-reflection film are provided, for example, between the semiconductor layer 10 and the filter 25. The fixed charge film is a film having a fixed charge and can be formed using a high dielectric material. For example, the fixed charge film is made of a metal oxide such as hafnium oxide or aluminum oxide.

[0074] The fixed charge film is, for example, a film having a negative fixed charge. By providing the fixed charge film, the generation of dark current at the interface of the semiconductor layer 10 is suppressed. The fixed charge film may be formed of another metal oxide film, or may be formed using a metal nitride film or a metal oxynitride film. A film having a positive fixed charge may be provided as the fixed charge film.

[0075] The anti-reflection film is made of, for example, a metal oxide such as hafnium oxide or tantalum oxide. The anti-reflection film is provided, for example, so as to be stacked with the fixed charge film. The anti-reflection film is provided, for example, on the surface 11S1 side of the semiconductor layer 10, and reduces (suppresses) reflection.

[0076] The anti-reflection film may be made of an insulating material such as silicon nitride (SiN), silicon oxide (SiO), aluminum oxide (AlO), or other materials. The insulating layer 70 may be made of at least one of a fixed charge film and an anti-reflection film.

[0077] The light guiding unit 50 is provided above the photoelectric conversion unit 12, for example, as in the example shown in Fig. 6. Light from a subject to be measured is incident on the light guiding unit 50 of each pixel P of the imaging device 1. For example, light that has passed through an optical system such as an imaging lens is incident on the multiple structures 41 of the light guiding unit 50. The structures 41 are structures whose size is equal to or smaller than a predetermined wavelength of the incident light.

[0078] The light guide unit 50 has a plurality of nanostructures 41, and is configured to guide light from the measurement target to the photoelectric conversion unit 12. The structures 41 have, for example, a size equal to or smaller than the wavelength range of the light to be measured. The structures 41 may have a size equal to or smaller than the wavelength range of visible light, or may have a size equal to or smaller than the wavelength range of infrared light.

[0079] 6, the structures 41 of the light-guiding unit 50 have a spherical shape and are arranged side by side in the left-right direction (X-axis direction) on the page, with a part of the filling member 45 sandwiched between them. Note that the shape of the structures 41 may be an ellipsoidal shape.

[0080] A plurality of structures 41 having a spherical or ellipsoidal shape are provided in the optical layer 60. Each structure 41 may have, for example, a circular or ellipsoidal side shape. Note that the shape of the structures 41 may be approximately spherical or approximately ellipsoidal as long as it can achieve predetermined performance.

[0081] The light-guiding unit 50 has a filling member 45 provided around the structures 41. The filling member 45 is provided in the optical layer 60 so as to fill the areas around the structures 41. For example, the filling member 45 is formed on the insulating layer 70 so as to fill the spaces between adjacent structures 41.

[0082] 6 , the filling member 45 may be formed so as to cover the structures 41. For example, the filling member 45 is a protective member (protective layer) and is formed so as to entirely cover the plurality of structures 41. It can be said that the structures 41 are provided within the filling member 45 and are arranged by replacing part of the filling member 45.

[0083] The light guide unit 50 uses the structure 41, which is a nanostructure, to propagate light toward the photoelectric conversion unit 12. The structure 41 is also called a meta-atom, a nano-atom, a metasurface structure, a microstructure, etc. The light guide unit 50 is an optical element (optical member) that guides (propagates) light. The light guide unit 50 can be said to be a light guide element configured to be able to guide light. The light guide unit 50 is provided, for example, for each pixel P or for each plurality of pixels P (i.e., for each predetermined number of pixels P).

[0084] As an example, the light-guiding unit 50 is configured as a spectroscopic element (spectroscopic unit) that disperses light. The light-guiding unit 50 is configured, for example, to impart a phase delay to incident light and guide the light. In the optical layer 60, a plurality of structures 41 are arranged so as to impart a desired phase profile to the incident light. As an example, the plurality of structures 41 are arranged side by side in the X-axis direction and the Y-axis direction in a planar view, as in the example shown in FIG. 4 (or FIG. 5 ).

[0085] In each pixel P of the imaging device 1, a plurality of structures 41 may be arranged at intervals equal to or less than a predetermined wavelength of incident light. As an example, the plurality of structures 41 are provided in the X-axis direction and the Y-axis direction at intervals equal to or less than the wavelength range of visible light. Note that the plurality of structures 41 may also be arranged at intervals equal to or less than the wavelength range of infrared light.

[0086] The structures 41 of the light-guiding unit 50 have a refractive index different from that of the adjacent medium. In the example shown in Fig. 6, the structures 41 have a refractive index different from that of the filling member 45. The structures 41 have a refractive index different from that of the medium layer formed around the structures 41, i.e., the filling member 45. The filling member 45 can also be said to be a material layer having a refractive index different from that of the structures 41.

[0087] The structure 41 of the light-guiding unit 50 has, for example, a refractive index higher than that of the filling member 45. The structure 41 can be made of a material having a refractive index higher than that of the filling member 45. The structure 41 is made of, for example, titanium oxide (TiO). Note that the structure 41 may also be made of silicon, polysilicon (Poly-Si), amorphous silicon (a-Si), germanium (Ge), or the like.

[0088] The structure 41 may be made of a simple substance, oxide, nitride, oxynitride, or composite of titanium (Ti), hafnium (Hf), zirconium (Zr), aluminum (Al), tantalum (Ta), indium (In), niobium (Nb), etc. The structure 41 may also be made of other metal compounds (metal oxides, metal nitrides, etc.).

[0089] The structure 41 of the light-guiding unit 50 may have a refractive index lower than that of the filling member 45. The structure 41 may be made of a material having a refractive index lower than that of the filling member 45. The structure 41 may be made of, for example, magnesium fluoride (MgF).

[0090] The structure 41 may be formed using silicon oxide, silicon nitride, silicon nitride oxide, silicon carbide, silicon oxide carbide, or other silicon compounds. The structure 41 may also be configured using an organic material. The structure 41 may also be configured using a siloxane-based resin, a styrene-based resin, an acrylic-based resin, or the like. The structure 41 may also be formed using beads (filler).

[0091] The filling member 45 is made of, for example, an inorganic material such as an oxide, a nitride, or an oxynitride. The filling member 45 may also be made of, for example, silicon oxide, silicon nitride, silicon oxynitride, or silicon carbide. The filling member 45 and a part or all of the insulating layer 70 may be integrally formed. The filling member 45 may also be made of an organic material.

[0092] The filling member 45 may be made of a siloxane-based resin, a styrene-based resin, an acrylic-based resin, or the like. The filling member 45 may be made of a material in which any of these resins contains fluorine. The filling member 45 may be made of a material in which any of these resins is filled with beads having a refractive index higher (or lower) than that of the resin.

[0093] The materials of the structure 41 and the filling member 45 can be selected depending on the refractive index difference with the surrounding medium, the wavelength range of incident light to be measured, etc. The structure 41 and the filling member 45 may be made of an inorganic material or an organic material. Furthermore, the structure 41 or the filling member 45 may be made of a void (cavity). For example, the filling member 45 may be made to contain air (voids).

[0094] The light-guiding unit 50 can control the wavefront of the light by, for example, causing a phase delay in the incident light due to a difference in refractive index between the structure 41 and the surrounding medium. The light-guiding unit 50 can adjust the propagation direction of the light by, for example, imparting a phase delay to the incident light using the structure 41 and the filling member 45 around the structure 41.

[0095] In the imaging device 1, for example, the average refractive index in the light-guiding section 50 changes depending on the area (or volume) occupied by the structures 41 per unit area (or unit volume). Therefore, for example, the average refractive index can be changed by adjusting the diameter of the spherical structures 41, and the amount of phase delay in the light-guiding section 50 can be adjusted.

[0096] In each pixel P of the imaging device 1, for example, the effective refractive index of the light guide section 50 by the structures 41 and the filling member 45 is adjusted according to the filling rate (occupancy rate) of the spherical or ellipsoidal structures 41, and the amount of phase delay of light in each wavelength range can be set. By adjusting the size of each structure 41, the amount of phase delay can be controlled, and a desired phase distribution can be realized.

[0097] The materials of the structures 41 and the filling member 45 (optical constants of each material), the size of the structures 41 (width (diameter), height, etc.), the pitch (arrangement interval), etc. are determined so that light of a desired wavelength range among the incident light from the measurement target travels in a desired direction. For example, the material (refractive index), dimensions, pitch, and material (refractive index) of the structures 41 and the filling member 45 can be set.

[0098] The light guide unit 50 is configured as, for example, a spectroscopic unit (spectroscopic element) capable of separating incident light. The light guide unit 50 can also be referred to as a splitter (color splitter). The light guide unit 50 (or the optical layer 60) can also be referred to as a color splitter layer, a wavelength separation layer, or a metasurface layer. The light guide unit 50 can also be referred to as an optical element configured to redirect light.

[0099] The light-guiding unit 50 can adjust the propagation direction of light by, for example, imparting different amounts of phase delay depending on the wavelength of the light, and can separate the incident light into light of each wavelength range. The propagation direction of light of each wavelength by the light-guiding unit 50 can be adjusted by the material, width, height, arrangement position, etc. of the structure 41.

[0100] As an example, in the imaging device 1, the material, size, arrangement position, and the like of the structures 41 are determined so that light in a specific wavelength band to be detected branches off and travels to the photoelectric conversion unit 12 of the desired pixel P. The light guide unit 50 includes a plurality of structures 41 and can be configured to split incident light.

[0101] The structures 41 of the light guide unit 50 may be provided so as to contact the insulating layer 70, for example, as in the example shown in Fig. 7 . The multiple structures 41 may be located at different distances (intervals) from the semiconductor layer 10 (or the insulating layer 70). For example, in order to obtain desired optical characteristics (e.g., spectral characteristics), multiple structures 41 may be provided at different height positions from the semiconductor layer 10 (or the insulating layer 70), as in the example shown in Fig. 8 . The light guide unit 50 may be provided for multiple adjacent pixels P.

[0102] 9A and 9B are diagrams showing examples of cross-sectional configurations at different image heights of the imaging device according to the first embodiment. Fig. 9B shows an example of the cross-sectional configuration in a region where the distance from the center of the pixel unit 100, i.e., the image height, is higher than in Fig. 9A . In the examples shown in Fig. 9A and 9B , a light guide unit 50 is provided for a plurality of adjacent pixels P.

[0103] For example, light from an optical lens is incident almost perpendicularly on the central portion of the pixel unit 100 of the imaging device 1. Light is incident obliquely on the peripheral portion located outside the central portion, i.e., on the region farther from the center of the pixel unit 100, as shown in the example schematically indicated by the hollow arrows in Fig. 9B . Therefore, in the imaging device 1, the position of the light guide unit 50 (or the structure 41) in each pixel P can be configured to differ depending on the distance from the center of the pixel unit 100, i.e., the image height.

[0104] 9B , the light guide unit 50 having the structure 41 is disposed, for example, shifted toward the center of the pixel unit 100 with respect to the filter 25 and the photoelectric conversion unit 12. In the example shown in FIG. 9B , the light guide unit 50 is also shifted rightward with respect to the filter 25 and the photoelectric conversion unit 12 of the pixel P.

[0105] In the pixel unit 100 of the imaging device 1, the position of the light guide unit 50 including the structures 41 is adjusted according to the image height, thereby enabling appropriate pupil correction. This makes it possible to suppress a decrease in the amount of light incident on the photoelectric conversion unit 12 of each pixel P, and to suppress a decrease in sensitivity to incident light.

[0106] The light guiding unit 50 imparts different phase delays to light in multiple wavelength ranges, for example, light in the first to third wavelength ranges, respectively, which enables the imaging device 1 to separate the light incident on the light guiding unit 50 into light in the first wavelength range, light in the second wavelength range, and light in the third wavelength range.

[0107] For example, the imaging device 1 may be configured to separate light in a first wavelength range, light in a second wavelength range, and light in a third wavelength range from light incident on the light guiding unit 50. As an example, the imaging device 1 may adjust the traveling direction of each of the first to third wavelength light, i.e., blue light, green light, and red light.

[0108] The light guide unit 50 of the pixel Pb is configured to be able to propagate, of the incident light, blue (B) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pb, and red (R) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pr. The light guide unit 50 of the pixel Pb splits the incident light and guides light in the red wavelength range of the incident light toward the pixel Pr.

[0109] Furthermore, the light guide unit 50 of the pixel Pb is configured to propagate green (G) light, of the incident light, to the filter 25 and the photoelectric conversion unit 12 of the pixel Pg. The light guide unit 50 of the pixel Pb splits the incident light and guides light in the green wavelength range, of the incident light, toward the pixel Pg.

[0110] The light guide unit 50 of the pixel Pr is configured to be able to propagate, of the incident light, red (R) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pr, and blue (B) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pb. The light guide unit 50 of the pixel Pr splits the incident light and guides light in the blue wavelength range of the incident light toward the pixel Pb.

[0111] Furthermore, the light guide unit 50 of the pixel Pr is configured to propagate green (G) light, of the incident light, to the filter 25 and the photoelectric conversion unit 12 of the pixel Pg. The light guide unit 50 of the pixel Pr splits the incident light and guides light in the green wavelength range, of the incident light, toward the pixel Pg.

[0112] The light guide unit 50 of the pixel Pg is configured to be able to propagate, of the incident light, green (G) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pg, and blue (B) light to the filter 25 and photoelectric conversion unit 12 of the pixel Pb. The light guide unit 50 of the pixel Pg splits the incident light and guides light in the blue wavelength range of the incident light toward the pixel Pb.

[0113] Furthermore, the light guide unit 50 of the pixel Pg is configured to propagate red (R) light, of the incident light, to the filter 25 and the photoelectric conversion unit 12 of the pixel Pr. The light guide unit 50 of the pixel Pg splits the incident light and guides light in the red wavelength range, of the incident light, toward the pixel Pr.

[0114] 10A, the pixels surrounding pixel Pb guide blue wavelength light from the incident light toward pixel Pb. The blue light incident on pixel Pb and the blue light incident on each of the surrounding pixels can be concentrated on filter 25 and photoelectric conversion unit 12 of pixel Pb. The photoelectric conversion unit 12 of pixel Pb can efficiently receive light in the blue wavelength range, perform photoelectric conversion, and generate electric charges according to the amount of received light.

[0115] As shown schematically by the arrows in Figure 10B, the pixels surrounding pixel Pg guide green wavelength light of the incident light toward pixel Pg. The green light incident on pixel Pg and the green light incident on each of the surrounding pixels can be concentrated on filter 25 and photoelectric conversion unit 12 of pixel Pg. The photoelectric conversion unit 12 of pixel Pg can efficiently receive light in the green wavelength range and perform photoelectric conversion, thereby generating electric charges according to the amount of received light.

[0116] 10C , the pixels surrounding pixel Pr guide red wavelength light from the incident light toward pixel Pr. The red light incident on pixel Pr and the red light incident on each of the pixels surrounding pixel Pr can be focused onto pixel Pr's filter 25 and photoelectric conversion unit 12. The photoelectric conversion unit 12 of pixel Pr can efficiently receive light in the red wavelength range, perform photoelectric conversion, and generate electric charges according to the amount of received light.

[0117] In this way, in the imaging device 1, light to be detected can be effectively taken into the pixel P from pixels surrounding the pixel P, thereby improving quantum efficiency (QE). Note that the structures 41 of the light guide units 50 of the above-described pixels Pb, Pg, and Pr can be formed so as to differ in size (e.g., width, height), arrangement position, etc.

[0118] As described above, light from a subject, which is an object to be measured, is incident on each pixel P of the imaging device 1 via the light guiding unit 50. Each pixel P can receive the light incident via the structure 41 of the light guiding unit 50 and generate a pixel signal. The imaging device 1 can generate image data representing an image of the subject using, for example, the pixel signal obtained by photoelectric conversion in each pixel P.

[0119] Furthermore, for example, the imaging device 1 can generate image data (distance image data) relating to the distance to an object using the pixel signal of each pixel. In the imaging device 1, the light guiding unit 50 having the structure 41 can appropriately guide light in any wavelength range to the photoelectric conversion unit 12. This makes it possible to improve sensitivity to incident light.

[0120] As described above, the imaging device 1 is provided with spherical or ellipsoidal structures 41. Therefore, even when light is incident obliquely on the light-guiding unit 50, the incident light can be appropriately guided to the photoelectric conversion unit 12. By configuring the light-guiding unit 50 with spherical or ellipsoidal structures 41, it is possible to reduce the difference between the optical path length in the structures 41 for perpendicularly incident light and the optical path length in the structures 41 for obliquely incident light. This makes it possible to prevent the desired phase delay amount from being unavailable in the case of obliquely incident light.

[0121] In the imaging device 1, by providing the spherical or ellipsoidal structures 41, it is possible to reduce the difference between the amount of phase delay in the case of perpendicular incident light and the amount of phase delay in the case of oblique incident light. This makes it possible to reduce the difficulty of designing a color splitter, for example. Compared to when light is split using columnar (pillar-shaped) structures, it is possible to improve the characteristics for oblique incident light.

[0122] In this embodiment, it is possible to separate light incident at an angle to the structure 41 of the light-guiding section 50 and appropriately focus the light toward the photoelectric conversion section 12. It is possible to prevent the deterioration of spectral characteristics in the case of obliquely incident light. It is possible to prevent the occurrence of unnecessary reflected light or refracted light and to prevent a decrease in light utilization efficiency.

[0123] 11A to 11J are diagrams illustrating an example of a method for manufacturing the light guide portion of the imaging device according to the first embodiment. First, as shown in Fig. 11A, a filler member 45 is formed on the insulating layer 70, and a resist film 85a is formed on the filler member 45. Then, as shown in Fig. 11B, the resist film 85a is processed by lithography and etching.

[0124] 11C, the filler member 45 is wet-etched. Then, as shown in Fig. 11D, the resist film 85a is peeled off (removed). Furthermore, as shown in Fig. 11E, a material film 86 (for example, a titanium oxide film, an a-Si film, or the like) is formed as the material of the structure 41.

[0125] Next, as shown in Fig. 11F, a resist film 85b is formed on the material film 86. Then, as shown in Fig. 11G, the resist film 85b is processed by lithography and etching. Furthermore, as shown in Fig. 11H, the resist film 85b is subjected to a heat treatment so that the shape of the resist film 85b becomes hemispherical.

[0126] 11I, the resist film 85b and the material film 86 are anisotropically etched (for example, reactive ion etching (RIE)). As a result, excess portions of the material film 86 are removed, and spherical structures 41 are formed.

[0127] Then, as shown in Fig. 11J, filling member 45 is formed on structure 41. By the manufacturing method described above, light guiding section 50 shown in Fig. 6, Fig. 7, etc. can be manufactured. Note that the manufacturing method described above is merely one example, and other manufacturing methods may also be adopted.

[0128] [Actions and Effects] The light detection device according to this embodiment includes a first structure (structure 41) having a spherical or ellipsoidal shape, a first light-guiding member (light-guiding section 50) including a filler member (filler member 45) provided around the first structure and having a refractive index different from that of the first structure, and a first photoelectric conversion element (photoelectric conversion section 12) that photoelectrically converts light incident through the first light-guiding member.

[0129] The photodetector according to this embodiment is provided with a light guide unit 50 including structures 41 having a spherical or ellipsoidal shape. This allows the photodetector (imaging device 1) to appropriately guide obliquely incident light. This makes it possible to realize a photodetector capable of improving characteristics for obliquely incident light.

[0130] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0131] (1-1. Modification 1) In the above-described embodiment, configuration examples of the imaging device have been described, but the configuration of the imaging device is not limited to the above-described example. FIGS. 12A and 12B are diagrams for explaining a configuration example of an imaging device according to Modification 1 of the present disclosure. The imaging device 1 may have a plurality of structures 41 (structures 41a and 41b in FIGS. 12A and 12B) arranged so as to be stacked on top of each other.

[0132] The light-guiding unit 50 may have structures 41 and 41b each having a spherical or ellipsoidal shape. The structures 41b are provided so as to be stacked on the structures 41a. The filling member 45 is provided between adjacent structures 41a and between adjacent structures 41b. Furthermore, a portion of the filling member 45 is provided between the structures 41a and 41b.

[0133] The structures 41a and 41b may be arranged along the optical axis L1, for example, as shown in Fig. 12A or 12B. In a region where light from the measurement object is incident perpendicularly, the structures 41a and 41b are arranged along the optical axis L1 of an optical system such as an imaging lens, for example, as shown in the example of Fig. 12A. In a region where light from the measurement object is incident obliquely, the structures 41a and 41b may be arranged side by side along the optical axis L1 of the optical system, for example, as shown in the example of Fig. 12B.

[0134] The structures 41a and 41b may be formed to have different sizes, shapes, etc. The structures 41a and 41b may be made of the same material or different materials, and the structures 41a and 41b may have different refractive indices.

[0135] The structures 41b have, for example, a refractive index different from that of the structures 41a. The structures 41b may have a refractive index higher than that of the structures 41a. The structures 41b may be made of a material having a refractive index higher than that of the structures 41a and the refractive index of the filling member 45.

[0136] The structures 41b may have a refractive index lower than that of the structures 41a. The structures 41b may be made of, for example, a material having a refractive index lower than that of the structures 41a and that of the filling member 45. Note that the light-guiding unit 50 may be configured to include three or more types of structures 41 having different refractive indices.

[0137] 13A and 13B are diagrams for explaining another example configuration of the imaging device according to Modification 1. The structures 41a and 41b may have different sizes, as in the example shown in FIG. 13A or 13B. In the example shown in FIG. 13A and 13B, the size of the structures 41a is larger than the size of the structures 41b. Note that the light-guiding section 50 may be configured to include three or more types of structures 41 having different sizes.

[0138] (1-2. Modification 2) Fig. 14 is a diagram for explaining an example configuration of an imaging device according to Modification 2. A structure 41 has a first portion 42a and a second portion 42b. As in the example shown in Fig. 14, the second portion 42b of the structure 41 can be provided so as to cover the periphery of the first portion 42a. It can also be said that the first portion 42a is provided within the second portion 42b and is disposed by replacing part of the second portion 42b.

[0139] The first portion 42 a of the structure 41 has a refractive index different from that of the second portion 42 b. For example, the first portion 42 a may be made of a material having a refractive index lower than that of the second portion 42 b. Furthermore, for example, the first portion 42 a may have a refractive index higher than that of the second portion 42 b and the refractive index of the filling member 45.

[0140] The first portion 42a, the second portion 42b, and the filling member 45 may be configured to include different materials. For example, the first portion 42a has a refractive index n1, the second portion 42b has a refractive index n2, and the filling member 45 has a refractive index n0. As one example, the first portion 42a, the second portion 42b, and the filling member 45 may be arranged so that n1 < n2 < n0. As another example, the first portion 42a, the second portion 42b, and the filling member 45 may be arranged so that n1 < n0 < n2.

[0141] (1-3. Modification 3) FIGS. 15A and 15B are diagrams for explaining a configuration example of an imaging device according to Modification 3. The structure 41 has a first portion 42a and a second portion 42b. The first portion 42a and the second portion 42b each have a spherical or ellipsoidal shape. The first portion 42a and the second portion 42b are provided so as to be in contact with each other, as in the example shown in FIG. 15A or 15B. The first portion 42a and the second portion 42b may be provided so as to be aligned with the optical axis L1 of the optical lens.

[0142] For example, at least a portion of the first portion 42a of the structure 41 may be provided within the second portion 42b. The second portion 42b may be formed to include at least a portion of the first portion 42a. It can also be said that a portion of the first portion 42a is disposed in place of the second portion 42b. Furthermore, for example, at least a portion of the second portion 42b may be provided within the first portion 42a. The first portion 42a may be formed to include at least a portion of the second portion 42b.

[0143] (1-4. Modification 4) FIGS. 16A and 16B are diagrams for explaining a configuration example of an imaging device according to Modification 4. The light guiding section 50 of the imaging device 1 may have an anti-reflection film 61. The anti-reflection film 61 (anti-reflection film) may be formed in the light guiding section 50 so as to cover at least a portion of the structure 41. The anti-reflection film 61 is provided, for example, on the side of the structure 41 where light is incident, and is located on the structure 41. At least a portion of the anti-reflection film 61 is provided on the optical axis L1.

[0144] 16A and 16B , the anti-reflection film 61 may be formed on the optical axis L1. The anti-reflection film 61 may be made of a metal compound, a silicon compound, or other material. The anti-reflection film 61 may be made of a laminate of multiple films. The anti-reflection film 61 may be provided so as to entirely cover one or multiple structures 41.

[0145] For example, the structure 41 has a refractive index n2, the anti-reflection film 61 has a refractive index n1, and the filling member 45 has a refractive index n0. As one example, the structure 41, the anti-reflection film 61, and the filling member 45 may be provided so as to satisfy n0 > n1 > n2. As another example, the structure 41, the anti-reflection film 61, and the filling member 45 may be provided so as to satisfy n2 > n1 > n0.

[0146] In the imaging device 1 according to this modification, the provision of the anti-reflection film 61 can reduce reflection in the light-guiding unit 50. This can prevent unnecessary reflected light from occurring in each pixel P of the imaging device 1, and can prevent a decrease in light utilization efficiency.

[0147] 17A and 17B are diagrams illustrating another example configuration of an imaging device according to Modification 4. The light guiding unit 50 of the imaging device 1 may have an antireflection film 61a and an antireflection film 61b as the antireflection film 61 (reflection suppression film) as shown in FIG. 17A or 17B . For example, the antireflection film 61a is provided on the side of the structure 41 where light is incident. Furthermore, the antireflection film 61b is provided on the side of the structure 41 opposite to the side where light is incident.

[0148] The anti-reflection films 61a and 61b may be made of the same material or different materials. The anti-reflection films 61a and 61b may have different refractive indices. The light-guiding unit 50 may be configured to include only one of the anti-reflection films 61a and 61b.

[0149] (1-5. Modification 5) FIGS. 18A to 18D are diagrams for explaining a configuration example of an imaging device according to Modification 5. The structure 41 may have an ellipsoidal shape, as in the example shown in FIGS. 18A to 18D. The structure 41 may be provided so that the major axis (major diameter) of the elliptical structure 41 is aligned with the optical axis L1. For example, the structure 41 may be provided so that the minor axis (minor diameter) of the structure 41 intersects (for example, is perpendicular to) the optical axis L1.

[0150] The structures 41 of the light guiding section 50 may be provided such that the minor axis (minor diameter) of the elliptical structures 41 is aligned with the optical axis L1. For example, the structures 41 may be provided such that the major axis (major diameter) of the structures 41 intersects (e.g., is perpendicular to) the optical axis L1. Note that in the imaging device 1, a plurality of elliptical structures 41 may be provided so as to be stacked on top of each other.

[0151] (1-6. Modification 6) Light guiding unit 50, which is an optical element, may be configured as a lens that condenses light, depending on the design of structure 41. Light guiding unit 50 may also be configured as an optical element that controls the polarization state of light. In these cases, light guiding unit 50 is called a metalens (metamaterial lens), a polarizing metalens, or the like.

[0152] The light guiding unit 50 may be configured as a filter that selectively transmits light in a specific wavelength range from among incident light. The light guiding unit 50 may be configured as an optical element (called a deflector) that changes the traveling direction of light in a specific wavelength range. The optical element (light guiding unit 50) and photodetector according to the present disclosure can be applied to various devices.

[0153] 2. Second Embodiment Next, a second embodiment of the present disclosure will be described. In the following, components similar to those in the above-described embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0154] Fig. 19 is a diagram showing an example of a planar configuration of an imaging device according to a second embodiment of the present disclosure. Fig. 20 is a diagram showing an example of a cross-sectional configuration of the imaging device according to the second embodiment. In the imaging device 1 according to this embodiment, the density of the structures 41 in the light guiding unit 50 of each pixel P can be configured to be different. For example, the imaging device 1 is configured so that the density of the spherical or ellipsoidal structures 41 is different for each pixel P of each color.

[0155] The light guide units 50 of the pixels Pr, Pg, and Pb of the imaging device 1 may be formed so that the densities of the structures 41 are different from one another. For example, in order to obtain desired optical characteristics, the area (or volume) occupied by the structures 41 in the light guide unit 50 (or optical layer 60) of each pixel P is adjusted. As shown in FIG. 19 , the densities of the structures 41 in the pixels Pr, Pg, and Pb are different from one another.

[0156] 19 , the imaging device 1 is configured such that the number of structures 41 in the light guide section 50 of pixel Pr, the number of structures 41 in the light guide section 50 of pixel Pg, and the number of structures 41 in the light guide section 50 of pixel Pb are different from each other. Note that the structures 41 in the pixels P of each color may all have the same size.

[0157] 19 and 20 , for example, the density (or number) of structures 41 in the light guide section 50 of pixel Pr is greater than the density (or number) of structures 41 in the light guide section 50 of pixel Pb. Furthermore, the density of structures 41 in the light guide section 50 of pixel Pr is less than the density of structures 41 in the light guide section 50 of pixel Pg. Note that the number, arrangement, etc. of structures 41 in each pixel P (or light guide section 50) can be set appropriately according to desired optical characteristics (e.g., spectral characteristics).

[0158] In the imaging device 1 according to the present embodiment, the amount of phase delay in the light guiding unit 50 is adjusted according to the density of the spherical or ellipsoidal structures 41, thereby enabling phase control of light. For example, the amount of phase delay can be controlled according to the density difference of the structures 41, thereby enabling appropriate phase design (phase control) of the light guiding unit 50 as a color splitter. This makes it possible to suppress degradation of spectral characteristics in the case of obliquely incident light.

[0159] Fig. 21 is a diagram illustrating an example of the configuration of an imaging device according to the second embodiment. Fig. 21 shows an example of a cross-sectional configuration in a region where the distance from the center of the pixel unit 100, i.e., the image height, is higher than in the case of Fig. 20. In the imaging device 1 of this embodiment, too, the position of the light guiding unit 50 (or the structure 41) in each pixel P is adjusted according to the image height, allowing pupil correction to be performed appropriately. This makes it possible to suppress unevenness (shading) in an image generated using pixel signals from each pixel P.

[0160] [Operations and Effects] The photodetector according to this embodiment includes a first structure (structure 41) having a spherical or ellipsoidal shape, a first light guide member (e.g., light guide section 50 of pixel Pg) including a filler member (filler member 45) provided around the first structure and having a refractive index different from that of the first structure, and a first photoelectric conversion element (photoelectric conversion section 12) that photoelectrically converts light incident through the first light guide member. The photodetector further includes a second light guide member (e.g., light guide section 50 of pixel Pb (or pixel Pr)) that includes the first structure and the filler member, and a second photoelectric conversion element that photoelectrically converts light incident through the second light guide member. The density of the first structures in the first light guide member is different from the density of the first structures in the second light guide member.

[0161] In the photodetector according to the present embodiment, for example, the density of the structures 41 in the light guide unit 50 of pixel Pg is different from the density of the structures 41 in the light guide unit 50 of pixel Pb. Phase control can be performed by the density difference between the structures 41 having a spherical or ellipsoidal shape. It is possible to realize a photodetector capable of improving characteristics for obliquely incident light.

[0162] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0163] (2-1. Modification 7) Fig. 22 is a diagram illustrating an example configuration of an imaging device according to Modification 7. The structure 41 has a first portion 42a and a second portion 42b. The first portion 42a and the second portion 42b each have a hemispherical shape, for example. Note that the first portion 42a and the second portion 42b may each have a semi-ellipsoidal shape.

[0164] The imaging device 1 may have an intermediate layer 65, as in the example shown in FIG. 22 . The intermediate layer 65 is an etching stopper layer (stopper film) and is provided between the first portion 42 a and the second portion 42 b. The intermediate layer 65 can also be considered a spacer layer. In the imaging device 1, the provision of the intermediate layer 65 (stopper layer) makes it possible to improve the processing controllability of the first portion 42 a and the second portion 42 b of the structure 41.

[0165] The structures 41a and 41b may be made of the same material or different materials. The structures 41a and 41b may have different refractive indices. By selecting the materials for the structures 41a and 41b, the refractive index pattern can be increased, making phase control easier. The material for the intermediate layer 65 can be selected depending on, for example, the material for the first portion 42a, the material for the second portion 42b, the material for the filler member 45, etc.

[0166] (2-2. Modification 8) Fig. 23 is a diagram for explaining an example configuration of an imaging device according to Modification 8. A structure 41 has a first portion 42a and a second portion 42b. The second portion 42b of the structure 41 can be provided so as to cover the periphery of the first portion 42a, as in the example shown in Fig. 23. The first portion 42a of the structure 41 has a refractive index different from that of the second portion 42b.

[0167] As an example, the first portion 42 a, the second portion 42 b, and the filling member 45 may be made of different materials. For example, the first portion 42 a has a refractive index n1, the second portion 42 b has a refractive index n2, and the filling member 45 has a refractive index n0. The first portion 42 a, the second portion 42 b, and the filling member 45 may be formed so as to satisfy n1<n2<n0, or so as to satisfy n1<n0<n2.

[0168] In the imaging device 1 according to this modification, the amount of phase delay of light can be finely adjusted by combining a plurality of materials to form the structure 41. This makes it possible to improve the optical characteristics of the light-guiding unit 50, and to achieve, for example, high light-collection performance.

[0169] 24A and 24B are diagrams illustrating an example configuration of an imaging device according to Modification 9. The imaging device 1 may have a plurality of structures 41 (structures 41a and 41b in FIGS. 24A and 24B ) stacked on top of each other. An intermediate layer 65 may be provided between the layer (level 101) on which the structures 41a are provided and the layer (level 102) on which the structures 41b are provided.

[0170] The imaging device 1 may be configured so that the number and arrangement of the structures 41a on the story 101 differs from the number and arrangement of the structures 41b on the story 102. For example, as shown in the example of Fig. 24B, the number of the structures 41a arranged on the story 101 may differ from the number of the structures 41b arranged on the story 102. In the imaging device 1 according to this modification, it is possible to perform different phase difference control for each story.

[0171] 25A and 25B are diagrams for explaining a configuration example of an imaging device according to Modification 10. Each light guiding section 50 of the imaging device 1 may have a plurality of types of structures 41 (structures 41a, 41b, and 41c in FIGS. 25A and 25B). The structures 41a to 41c are made of different materials.

[0172] 25A or 25B , the structures 41b are disposed around the structures 41a and have a refractive index different from that of the structures 41a. Furthermore, the structures 41c are disposed around the structures 41a and have a refractive index different from that of the structures 41a and 41b. The imaging device 1 may be configured such that the number and arrangement of the structures 41a to 41c differ for each pixel P of each color, for example.

[0173] 26A and 26B are diagrams illustrating another example configuration of an imaging device according to Modification 10. In imaging device 1, different structures 41 may be arranged on each level. For example, as shown in FIG. 26A , structures 41a may be arranged on level 101, and structures 41b may be arranged on level 102. Furthermore, for example, in imaging device 1, the number of structures 41a to 41c arranged may differ depending on the level and pixel position, as in the example shown in FIG. 26B .

[0174] (2-5. Modification 11) FIG. 27 is a diagram illustrating an example configuration of an imaging device according to Modification 11. The structures 41 may have an ellipsoidal shape. In the example shown in FIG. 27, ellipsoidal structures 41b are provided in the optical layer 60. The structures 41b may be arranged such that the minor axis (minor diameter) of the structures 41b is aligned with the optical axis L1, for example. The light guiding section 50 may have spherical structures 41a and ellipsoidal structures 41b. It is possible to control the phase difference by the density and width of the structures 41a and 41b.

[0175] (2-6. Modification 12) FIG. 28 is a diagram illustrating an example of the configuration of an imaging device according to Modification 12. As in the example shown in FIG. 28, the light guide section 50 may have structures 42 having a columnar (pillar) shape. For example, a cylindrical structure 42 may be disposed in one type of pixel (for example, pixel Pr) among pixels Pr, Pg, and Pb. In the imaging device 1 according to this modification, the spherical or ellipsoidal structures 41 and the columnar structures 42 can finely adjust the phase difference of light in each wavelength range. This makes it possible to improve the accuracy of phase difference control.

[0176] 3. Third Embodiment Next, a third embodiment of the present disclosure will be described. The technology according to the present disclosure is applicable to various electronic devices, optical devices, etc. The light guide unit (light guide unit 50) configured using the nanostructure described above is applicable to various optical elements (optical members). In the following, components similar to those in the above-described embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0177] 29 is a diagram illustrating a configuration example of an optical element according to a third embodiment of the present disclosure. The optical element 200 includes a substrate 120 and a plurality of structures 41. The optical element 200 is an optical element (optical member) configured using the structures 41, which are nanostructures, and can be configured as a metalens (metamaterial lens).

[0178] The substrate 120 is a substrate (transparent substrate) that transmits light, and is made of, for example, a glass substrate. As an example, the substrate 120 (base material) can be made of a material having a refractive index lower than that of the structure 41. The substrate 120 may be made of quartz glass, borosilicate glass, or the like, or may be made of a resin substrate. The substrate 120 (base material) may also be made of another material that transmits the light to be measured.

[0179] As shown in Fig. 29 , the substrate 120 has opposing surfaces 12S1 and 12S2. Surface 12S2 is the surface opposite to surface 12S1. The plurality of structures 41 are provided, for example, on the light-incident side of the substrate 120. In the example shown in Fig. 29 , an optical layer 60 including the plurality of structures 41 and a filler member 45 is formed on surface 12S1 of the substrate 120. Note that the structures 41 may be provided so as to be in contact with the substrate 120, as in the example shown in Fig. 30 .

[0180] The structures 41 of the optical element 200 have a spherical or ellipsoidal shape. The optical layer 60 including the structures 41 may be provided on the side of the substrate 120 opposite to the side where light is incident (i.e., the side where light is emitted). The optical layer 60 may be stacked on the substrate 120 via an insulating layer on the light incident side or light exit side of the substrate 120. The shape of the substrate 120 is not particularly limited, and may be circular, rectangular, or another shape.

[0181] The optical element 200 may be configured as a lens such as a lens that condenses light or a lens that diffuses light. The optical element 200 may also be configured as a splitter that disperses incident light, a filter that transmits light in a specific wavelength range, a deflector that changes the traveling direction of light, or the like. The optical element 200 may be configured as, for example, a part of the optical system of various devices. The optical element 200 is also called a metasurface optical element.

[0182] [Actions and Effects] The optical element (optical element 200) according to this embodiment comprises a plurality of first structures (structures 41) each having a spherical or ellipsoidal shape, and a filling member (filling member 45) provided between adjacent first structures and having a refractive index different from that of the first structures.

[0183] The optical element 200 according to this embodiment is provided with a plurality of structures 41 each having a spherical or ellipsoidal shape and a filling member 45 having a refractive index different from that of the structures 41. This makes it possible to improve the characteristics with respect to obliquely incident light. It is possible to appropriately guide the incident light, and to realize an optical element with good optical characteristics.

[0184] 4. 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 video camera, a mobile phone with an imaging function, etc. Fig. 31 shows a schematic configuration of an electronic device 1000.

[0185] 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.

[0186] 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 as a pixel signal to the DSP circuit 1002.

[0187] The DSP circuit 1002 is a signal processing circuit that processes signals supplied from the imaging device 1. The DSP circuit 1002 outputs image data obtained by processing the signals from the imaging device 1. The frame memory 1003 temporarily stores the image data processed by the DSP circuit 1002 on a frame-by-frame basis.

[0188] The display unit 1004 is composed of 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 on a recording medium such as a semiconductor memory or a hard disk.

[0189] The operation unit 1006, in response to a user's operation, outputs operation signals for various functions of the electronic device 1000. The power supply unit 1007 supplies various types of power to the DSP circuit 1002, frame memory 1003, display unit 1004, recording unit 1005, and operation unit 1006 as needed.

[0190] 5. Application Examples (Application Examples to Mobile Bodies) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0191] FIG. 32 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.

[0192] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 32, 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0199] 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.

[0200] 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.

[0201] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 32, 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.

[0202] FIG. 33 is a diagram showing an example of the installation position of the imaging unit 12031.

[0203] In FIG. 33 , a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as the imaging unit 12031.

[0204] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The forward images acquired by the imaging units 12101 and 12105 are mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0205] 33 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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 image capturing unit 12031 of the above-described configuration. Specifically, for example, the image capturing device 1 or the like can be applied to the image capturing unit 12031. By applying the technology according to the present disclosure to the image capturing unit 12031, it becomes possible to obtain high-resolution captured images. It becomes possible to perform high-precision control using captured images in the mobile object control system.

[0211] (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.

[0212] FIG. 34 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.

[0213] 34 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.

[0214] 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.

[0215] 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.

[0216] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected by the optical system onto the image sensor. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0217] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various types of image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0218] 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.

[0219] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing the surgical site, etc.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light in a narrower band than the light irradiated during normal observation (i.e., white light) to capture high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, in what is known as narrow band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or may involve locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissues with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0225] FIG. 35 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0226] 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.

[0227] 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.

[0228] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be a single (so-called single-chip type) or multiple (so-called multi-chip type). When the imaging unit 11402 is composed of a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is composed of a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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 .

[0235] 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.

[0236] 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.

[0237] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0238] 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.

[0239] 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.

[0240] 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.

[0241] 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.

[0242] The above describes an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied. Of the above-described configurations, 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, it is possible to provide a high-definition endoscope 11100.

[0243] Although the present disclosure has been described above by way of embodiments, modifications, application examples, and applied examples, the present technology is not limited to the above-described embodiments, etc., and various modifications are possible. For example, although the modifications described above have been described as modifications of the above-described embodiments, the configurations of the modifications can be combined as appropriate.

[0244] In the above embodiments, an imaging device has been described as an example. However, the photodetector 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 ranging information. The photodetector (imaging device) may be applied to an image sensor, a ranging sensor, etc. Note that the present disclosure is not limited to a back-illuminated image sensor, but may also be applied to a front-illuminated image sensor.

[0245] The photodetector according to the present disclosure may also be applied as a distance measuring sensor capable of measuring distances using a time-of-flight (TOF) method. The light receiving element (photoelectric conversion unit) of each pixel may be an avalanche photodiode (APD). The light receiving element may be configured, for example, by a single-photon avalanche diode (SPAD). The photodetector (image capture device) may also be applied as a sensor capable of detecting events, for example, an event-driven sensor (also known as an event vision sensor (EVS), event-driven sensor (EDS), dynamic vision sensor (DVS), etc.).

[0246] According to an embodiment of the present disclosure, a photodetector includes a first structure having a spherical or ellipsoidal shape, a first light guide member including a filler member disposed around the first structure and having a refractive index different from that of the first structure, and a first photoelectric conversion element that photoelectrically converts light incident through the first light guide member. This allows the photodetector (image capture device) to appropriately guide obliquely incident light. This makes it possible to realize a photodetector that can improve its characteristics for obliquely incident light.

[0247] An optical element according to an embodiment of the present disclosure includes a plurality of first structures each having a spherical or ellipsoidal shape, and a filler member disposed between adjacent first structures and having a refractive index different from that of the first structures. This allows the optical element to appropriately guide incident light, thereby realizing an optical element with excellent optical properties.

[0248] Note that the effects described in this specification are merely examples and are not limited to those described, and other effects may be present. The present disclosure may also have the following configurations. (1) A photodetector including: a first structure having a spherical or ellipsoidal shape; a first light guide member including a filler member provided around the first structure and having a refractive index different from that of the first structure; and a first photoelectric conversion element that performs photoelectric conversion on light incident through the first light guide member. (2) The photodetector described in (1), in which the first light guide member includes a second structure provided around the first structure and having a spherical or ellipsoidal shape. (3) The photodetector described in (2), in which the second structure has a refractive index different from that of the first structure. (4) The photodetector described in (2) or (3), in which the first structure and the second structure have different sizes. (5) The photodetector described in any one of (2) to (4), in which the second structure is provided so as to be stacked on the first structure. (6) The photodetector according to any one of (1) to (5), wherein the first structure includes a first portion and a second portion that is provided to cover the periphery of the first portion and has a refractive index different from that of the first portion. (7) The photodetector according to any one of (1) to (6), wherein the first structure has a first portion and a second portion that are spherical or elliptical in shape, and at least a part of the first portion is provided within the second portion. (8) The photodetector according to any one of (1) to (7), further comprising: a second light guide member that includes the first structure and the filling member; and a second photoelectric conversion element that photoelectrically converts light that is incident through the second light guide member, wherein a density of the first structures in the first light guide member is different from a density of the first structures in the second light guide member. (9) The photodetector according to (8), wherein the first structure includes a first portion having a hemispherical or semi-elliptical shape, and a second portion having a hemispherical or semi-elliptical shape and provided so as to be stacked on the first portion. (10) The photodetector according to (9), further including an intermediate layer provided between the first portion and the second portion.(11) The photodetector according to (9) or (10), wherein the first portion and the second portion contain different materials. (12) The photodetector according to any one of (1) to (11), further comprising: a second light guide member including second structures having a spherical or ellipsoid shape and the filling member provided around the second structures; and a second photoelectric conversion element that performs photoelectric conversion on light incident through the second light guide member, wherein the number of the first structures in the first light guide member is different from the number of the second structures in the second light guide member. (13) The photodetector according to (12), wherein the first structures and the second structures contain different materials. (14) The photodetector according to any one of (1) to (13), wherein the refractive index of the first structures is higher than the refractive index of the filling member. (15) The photodetector according to any one of (1) to (14), wherein the first structures have a size equal to or smaller than the wavelength range of visible light or equal to or smaller than the wavelength range of infrared light. (16) An optical element comprising: a plurality of first structures having a spherical or ellipsoidal shape; and a filler member provided between adjacent first structures and having a refractive index different from that of the first structures. (17) The optical element according to (16), further comprising a plurality of second structures having a spherical or ellipsoidal shape, wherein the filler member is provided between adjacent first structures and between adjacent second structures. (18) The optical element according to (17), wherein the second structures have a refractive index different from that of the first structures. (19) The optical element according to (17) or (18), wherein the second structures are provided so as to be stacked on the first structures. (20) An electronic device comprising: an optical system; and a photodetector that receives light transmitted through the optical system, wherein the photodetector has: a first structure having a spherical or ellipsoidal shape; a first light-guiding member that includes a filler member that is provided around the first structure and has a refractive index different from that of the first structure; and a first photoelectric conversion element that photoelectrically converts light incident through the first light-guiding member.

[0249] This application claims priority based on Japanese Patent Application No. 2023-118666, filed on July 20, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0250] 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 light detection device comprising: a first structure having a spherical or ellipsoidal shape; a first light guiding member including a filler member provided around the first structure and having a refractive index different from that of the first structure; and a first photoelectric conversion element that photoelectrically converts light incident through the first light guiding member.

2. The optical detection device according to claim 1, wherein the first light guide member has a second structure arranged around the first structure and having a spherical or ellipsoidal shape.

3. The optical detection device according to claim 2, wherein the second structure has a refractive index different from that of the first structure.

4. The light detection device according to claim 2, wherein the first structure and the second structure have sizes different from each other.

5. The photodetector according to claim 2, wherein the second structure is provided so as to be stacked on the first structure.

6. The optical detection device according to claim 1, wherein the first structure includes a first portion and a second portion that is provided to surround the first portion and has a refractive index different from that of the first portion.

7. The optical detection device according to claim 1, wherein the first structure has a first portion and a second portion having a spherical or elliptical shape, and at least a portion of the first portion is provided within the second portion.

8. The light detection device of claim 1, further comprising: a second light-guiding member including the first structures and the filling member; and a second photoelectric conversion element that performs photoelectric conversion on light incident through the second light-guiding member, wherein the density of the first structures in the first light-guiding member is different from the density of the first structures in the second light-guiding member.

9. The optical detection device according to claim 8, wherein the first structure includes a first portion having a hemispherical or semi-elliptical shape, and a second portion arranged to be stacked on the first portion and having a hemispherical or semi-elliptical shape.

10. The optical detection device according to claim 9, further comprising an intermediate layer provided between said first portion and said second portion.

11. The optical detection device of claim 9, wherein the first portion and the second portion comprise different materials.

12. The light detection device of claim 1, further comprising: a second light-guiding member including a second structure having a spherical or ellipsoidal shape and the filling member provided around the second structure; and a second photoelectric conversion element that performs photoelectric conversion on light incident through the second light-guiding member, wherein the number of the first structures in the first light-guiding member is different from the number of the second structures in the second light-guiding member.

13. The optical detection device according to claim 12, wherein the first structure and the second structure include different materials.

14. The light detection device according to claim 1, wherein the refractive index of the first structure is higher than the refractive index of the filling member.

15. The optical detection device according to claim 1, wherein the first structure has a size equal to or smaller than the wavelength range of visible light or equal to or smaller than the wavelength range of infrared light.

16. An optical element comprising: a plurality of first structures having a spherical or ellipsoidal shape; and a filler member provided between adjacent first structures and having a refractive index different from that of the first structures.

17. The optical element according to claim 16, further comprising a plurality of second structures having a spherical or ellipsoidal shape, the filling member being provided between adjacent pairs of the first structures and between adjacent pairs of the second structures.

18. The optical element according to claim 17, wherein the second structure has a refractive index different from the refractive index of the first structure.

19. The optical element according to claim 17, wherein the second structure is provided so as to be stacked on the first structure.

20. An electronic device comprising: an optical system; and a photodetector that receives light that has passed through the optical system, wherein the photodetector has: a first structure having a spherical or ellipsoidal shape; a first light-guiding member that is provided around the first structure and includes a filling member having a refractive index different from that of the first structure; and a first photoelectric conversion element that photoelectrically converts light incident through the first light-guiding member.

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