Light detection device, optical element, and electronic apparatus

Abstract

A light detection device includes a first layer including a plurality of first structures having a first refractive index and a first medium disposed within the first layer and having a second refractive index, where the first refractive index is different from the second refractive index, and a second layer including a plurality of second structures having a second refractive index. The second layer includes a plurality of second structures having a third refractive index and a second medium disposed within the second layer and having a fourth refractive index, wherein the third refractive index is different from the fourth refractive index. The second layer is laminated over the first layer, the plurality of first structures comprise a first material, the plurality of second structures comprise a second material, the first material and the second material are different materials from each other, and at least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Japanese priority patent application JP 2023-143525, filed on September 5, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a light detection device, optical element, and electronic device. Background Technology

[0004] An image sensor has been proposed that includes a first lens layer having a plurality of nanopillars, a second lens layer having a plurality of nanopillars, and an etch-prevention layer disposed between the first lens layer and the second lens layer (Patent Document 1).

[0005] [List of Citations]

[0006] [Patent Literature]

[0007] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2022-074062 Summary of the Invention

[0008] [Technical Issues]

[0009] For devices that detect light, it is desirable to improve the characteristics of incident light.

[0010] The aim is to provide a light detection device that can improve the characteristics of incident light.

[0011] [Solution to the problem]

[0012] The optical detection device according to an embodiment of this disclosure includes a first layer, a second layer stacked on the first layer, and a photoelectric conversion element. The first layer includes a plurality of first structures having a first refractive index and a first medium, the first medium being disposed within the first layer and having a second refractive index different from the first refractive index. The second layer includes a plurality of second structures having a third refractive index and a second medium, the second medium being disposed within the second layer and having a fourth refractive index different from the third refractive index. The light-receiving side of the photoelectric conversion element is adjacent to the first layer. The plurality of first structures include a first material and the plurality of second structures include a second material, wherein the first material and the second material are different materials from each other. At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

[0013] An optical element according to an embodiment of this disclosure includes a first layer and a first medium. The first layer includes a plurality of first structures having a first refractive index, and the first medium is disposed within the first layer and has a second refractive index. The first refractive index is different from the second refractive index. The optical element also includes a second layer and a second medium. The second layer includes a plurality of second structures having a third refractive index, and the second medium is disposed within the second layer and has a fourth refractive index. The third refractive index is different from the fourth refractive index. The second layer is stacked on top of the first layer. The plurality of first structures include a first material, and the plurality of second structures include a second material. The first material and the second material are different materials from each other, and at least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

[0014] An electronic device according to an embodiment of this disclosure includes an optical system and a light detection device for receiving light transmitted through the optical system. The light detection device includes a first layer and a first medium. The first layer includes a plurality of first structures having a first refractive index, and the first medium is disposed within the first layer and has a second refractive index. The first refractive index is different from the second refractive index. The optical system further includes a second layer and a second medium. The second layer includes a plurality of second structures having a third refractive index, and the second medium is disposed within the second layer and has a fourth refractive index. The third refractive index is different from the fourth refractive index. The second layer is stacked on top of the first layer. The optical system also includes a photoelectric conversion element. The light-receiving side of the photoelectric conversion element is adjacent to the first layer, and the plurality of first structures include a first material and the plurality of second structures include a second material. The first material and the second material are different materials from each other, and at least one of the plurality of first structures is in contact with at least one of the plurality of second structures. Attached Figure Description

[0015] Figure 1 This is a block diagram illustrating an example of the schematic configuration of an imaging apparatus as an example of a light detection device according to a first embodiment of the present disclosure.

[0016] Figure 2 This is a diagram showing an example of the pixel portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0017] Figure 3 This is an illustrative diagram illustrating an example of the circuit configuration of the pixels of an imaging apparatus according to a first embodiment of the present disclosure.

[0018] Figure 4 This is a diagram illustrating an example of the planar configuration of an imaging apparatus according to a first embodiment of the present disclosure.

[0019] Figure 5 This is a diagram illustrating an example of the cross-sectional configuration of an imaging apparatus according to a first embodiment of the present disclosure.

[0020] Figure 6A This is a diagram illustrating an example of the planar configuration of the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0021] Figure 6B This is a diagram illustrating an example of the planar configuration of the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0022] Figure 7 This is an explanatory diagram of another configuration example of an imaging apparatus according to the first embodiment of this disclosure.

[0023] Figure 8 This is an explanatory diagram of another configuration example of the light guide portion of the imaging apparatus according to the first embodiment of this disclosure.

[0024] Figure 9A This is an explanatory diagram illustrating an example of a method for manufacturing the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0025] Figure 9B This is an explanatory diagram illustrating an example of a method for manufacturing the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0026] Figure 9C This is an explanatory diagram illustrating an example of a method for manufacturing the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0027] Figure 9D This is an explanatory diagram illustrating an example of a method for manufacturing the light guide portion of an imaging apparatus according to a first embodiment of the present disclosure.

[0028] Figure 10 This is an explanatory diagram illustrating an example of the configuration of an optical element according to the second embodiment of this disclosure.

[0029] Figure 11 This is an explanatory diagram illustrating an example of the configuration of an optical element according to the second embodiment of this disclosure.

[0030] Figure 12 This is a block diagram illustrating an example of the configuration of an electronic device including an imaging apparatus.

[0031] Figure 13 This is a block diagram illustrating an example of the schematic configuration of a vehicle control system.

[0032] Figure 14 This is an example diagram illustrating the installation location of the vehicle exterior information detection unit and the imaging unit.

[0033] Figure 15 This is a view illustrating an example of the schematic configuration of an endoscopic surgical system.

[0034] Figure 16 This is a block diagram illustrating an example of the functional configuration of a camera and a camera control unit (CCU). Detailed Implementation

[0035] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the descriptions are given in the following order.

[0036] 1. First Implementation Plan

[0037] 2. Second Implementation Plan

[0038] 3. Applicable Examples

[0039] 4. Application Examples

[0040] <1. First Implementation Plan>

[0041] Figure 1 This is a block diagram illustrating an example of the schematic configuration of an imaging apparatus as an example of a light detection device according to a first embodiment of the present disclosure. Figure 2 This is a diagram illustrating an example of the pixel section of an imaging apparatus according to a first embodiment. A light detection device is a device configured to detect incident light. The imaging apparatus 1, as a light detection device, includes a plurality of pixels P, each pixel P including a photoelectric conversion unit (photoelectric conversion element), and is configured to perform photoelectric conversion on the incident light to generate a signal.

[0042] Imaging device 1 can receive light passing through an optical system (not shown) including optical lenses and generate signals. Imaging device 1 is constructed using a semiconductor substrate (e.g., a silicon substrate) having, for example, multiple pixels P. The photoelectric conversion unit of each pixel P in imaging device 1 is, for example, a photodiode (PD) and is configured to perform photoelectric conversion on light.

[0043] like Figure 1 and Figure 2 As shown, as an example, the imaging device 1 includes an imaging region (pixel section 100) in which multiple pixels P are arranged in a matrix in a two-dimensional configuration. The pixel section 100 of the imaging device 1 is a pixel array in which multiple pixels P are arranged, and may also be referred to as a light receiving region. The photoelectric conversion section of each pixel P may also be referred to as a photoelectric conversion region.

[0044] Imaging device 1 receives incident light (image light) from a subject being measured via an optical system including optical lenses. Imaging device 1 captures an image of the subject formed by the optical lenses. Imaging device 1 can perform photoelectric conversion on the received light to generate pixel signals. Imaging device 1, as a light detection device, is a device configured to receive incident light and generate signals, and can also be referred to as a light receiving device.

[0045] As an example, imaging device 1 (light detection device) can be configured as an image sensor. Imaging device 1 is, for example, a CMOS (Complementary Metal-Oxide-Semiconductor) image sensor. Imaging device 1 may include a structure (stacked structure) formed by stacking multiple semiconductor layers. Imaging device 1 can be used in various electronic devices, such as digital cameras, camcorders, and mobile phones.

[0046] It should be noted that, such as Figure 2 As shown, the direction of light incident from the subject is defined as the Z-axis; the left-right direction of the plane of the paper orthogonal to the Z-axis is defined as the X-axis; and the up-down direction of the plane of the paper orthogonal to both the Z-axis and X-axis is defined as the Y-axis. In the following figures, in some cases, Figure 2 The direction of the arrow in the image can be used as a reference for indicating direction.

[0047] [Schematic configuration of the imaging device]

[0048] as Figure 1 As shown in the example, the imaging apparatus 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. Furthermore, the imaging apparatus 1 is provided with multiple control lines Lread and multiple signal lines VSL. The control lines Lread are signal lines configured to transmit signals to control pixels P, and are connected to the pixel control unit 111 and the pixel P of the pixel unit 100.

[0049] exist Figure 1 In the example shown, in the pixel unit 100, multiple control lines Lread are provided for each pixel row comprising a plurality of pixels P arranged side-by-side in the horizontal direction (row direction). The control lines Lread are configured to transmit control signals to read signals from the pixels P. The control lines Lread can also be referred to as drive lines (pixel drive lines) that transmit signals to drive the pixels P.

[0050] A signal line VSL is a signal line configured to transmit signals from pixel P and is connected to pixel P and signal processing unit 112 of pixel unit 100. In pixel unit 100, for example, one or more signal lines VSL are provided for each pixel column comprising multiple pixels P arranged side-by-side in the vertical direction (column direction). The signal line VSL is configured to transmit signals output from pixel P. In imaging device 1, multiple signal lines VSL can be provided for one pixel column. Imaging device 1 may include multiple signal lines VSL for each pixel column.

[0051] The pixel control unit 111 is configured to control each pixel P of the pixel unit 100. The pixel control unit 111 is a control circuit and includes multiple circuits, including a buffer, a shift register, an address decoder, etc. The pixel control unit 111 generates signals for controlling the pixels P and outputs these signals to each pixel P of the pixel unit 100 via the 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.

[0052] For example, the pixel control unit 111 generates signals to control pixels P, such as signals controlling the transfer transistor of pixel P, signals controlling the selection transistor, and signals controlling the reset transistor, and supplies these signals to each pixel P via the control line Lread. The pixel control unit 111 can perform control to read out pixel signals from each pixel P. The pixel control unit 111 can also be referred to as a pixel driving unit configured to drive each pixel P. It should be noted that the pixel control unit 110 and the control unit 113 can also be collectively referred to as the pixel control unit.

[0053] The signal processing unit 112 is configured to perform signal processing on the input pixel signal. The signal processing unit 112 is a signal processing circuit and includes, for example, a load circuit, an AD (analog-to-digital) conversion circuit, a level selection switch, etc. As an example, the load circuit includes a current source configured to supply current to the amplifying transistor of pixel P. The load circuit and the amplifying transistor of pixel P together form a source follower circuit.

[0054] The signal processing unit 112 may include an amplifier circuit configured to amplify the signal read from pixel P via signal lines VSL. A load circuit, an amplifier circuit, an AD conversion circuit, etc., are provided for each of the multiple signal lines VSL. The load circuit, amplifier circuit, AD conversion circuit, etc., may be provided for each pixel column of the pixel unit 100.

[0055] 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 on the signals of the pixel P, such as AD conversion and CDS (correlated double sampling). The signals of each pixel P transmitted through each signal line VSL are processed by the signal processing unit 122 and output to the processing unit 114.

[0056] The processing unit 114 is configured to perform signal processing on the input signal. The processing unit 114 is a processing circuit and includes circuitry that performs various types of signal processing on the pixel signal, for example. The processing unit 114 may include a processor and a memory. The processing unit 114 performs signal processing on the pixel signal input from the signal processing unit 112 and outputs the processed pixel signal. The processing unit 114 can perform various types of signal processing, such as noise reduction processing and grayscale correction processing.

[0057] The control unit 113 is configured to control the various components of the imaging device 1. The control unit 113 can receive data such as clock signals and instruction operation modes supplied from an external source, and output data such as internal information about the imaging device 1. The control unit 113 is a control circuit and includes, for example, a timing generator configured to generate various timing signals. The control unit 113 controls the driving of the pixel control unit 111, signal processing unit 112, etc., based on the various timing signals (pulse signals, clock signals, etc.) generated by the timing generator.

[0058] The pixel unit 100, pixel control unit 111, signal processing unit 112, etc., can be disposed in a single substrate. Furthermore, the pixel control unit 111, signal processing unit 112, control unit 113, processing unit 114, etc., can be disposed in a single semiconductor substrate, or they can be disposed separately in multiple semiconductor substrates. The imaging device 1 can have a stacked structure formed by stacking multiple substrates. Some or all of the signal processing unit 112, control unit 113, and processing unit 114 can be integrally formed.

[0059] [Pixel Composition]

[0060] Figure 3 This is an explanatory diagram illustrating an example of the circuit configuration of a pixel in an imaging apparatus according to a first embodiment. 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 output a signal based on the charge generated by the photoelectric conversion. The readout circuit 20 can read out the pixel signal based on the charge generated by the photoelectric conversion performed by the photoelectric conversion unit 12.

[0061] The photoelectric conversion unit 12 is a light receiver (light receiving element) and is configured to generate charge through photoelectric conversion. Figure 3 In the example shown, the photoelectric conversion unit 12 is a photodiode (PD), which converts incident light into electrical charge. The photoelectric conversion unit 12 can perform photoelectric conversion to generate a charge corresponding to the amount of light received.

[0062] As an example, the readout circuit 20 includes a transistor TRG, a floating diffuser FD, a transistor AMP, a transistor SEL, and a transistor RST. Each of the transistors TRG, AMP, SEL, and RST is a MOS transistor (MOSFET) with gate, source, and drain terminals.

[0063] exist Figure 3In the example shown, each of transistors TRG, AMP, SEL, and RST includes an NMOS transistor. It should be noted that the transistor for pixel P may include a PMOS transistor.

[0064] The transistor TRG is a transfer transistor and is configured to transfer the charge generated by photoelectric conversion through the photoelectric conversion unit 12 to the floating diffusion unit FD. The transistor TRG is controlled by the signal STRG to electrically connect or disconnect the photoelectric conversion unit 12 and the floating diffusion unit FD from each other. The transistor TRG can transfer the charge generated and accumulated by photoelectric conversion through the photoelectric conversion unit 12 to the floating diffusion unit FD.

[0065] The floating diffuser FD is an accumulation section and is configured to accumulate the transferred charge. The floating diffuser FD can accumulate the charge generated by the photoelectric conversion of the photoelectric conversion section 12. The floating diffuser FD can also be called a holding section, and it is configured to hold the transferred charge. The floating diffuser FD accumulates the transferred charge and converts the transferred charge into a voltage corresponding to the capacitance of the floating diffuser FD.

[0066] The transistor AMP is configured to generate and output signals based on the charge accumulated in the floating diffuser FD. The transistor AMP is an amplifying transistor and can generate and output signals based on the charge generated by the conversion of the photoelectric conversion unit 12.

[0067] The gate of transistor AMP is electrically connected to the floating diffuser FD, and the voltage generated by the conversion through the floating diffuser FD is input to the gate of transistor AMP. Figure 3 In the example shown, the drain of the transistor AMP is connected to the power supply line to obtain the power supply voltage VDD.

[0068] The source of transistor AMP is connected to signal line VSL via transistor SEL. Transistor AMP is configured to generate a signal based on the charge accumulated in the floating diffuser FD, that is, a signal based on the voltage of the floating diffuser FD, and output the generated signal to signal line VSL.

[0069] The transistor SEL is configured to control the output of pixel signals. For example, as... Figure 3 As shown in the example, transistor SEL is electrically connected in series with transistor AMP. Transistor SEL is controlled by signal SSEL and is configured to output a signal from transistor AMP to signal line VSL. Transistor SEL is a selection transistor and controls the output timing of the pixel signal.

[0070] The transistor SEL is configured to output a signal based on the charge generated by the conversion through the photoelectric conversion unit 12. The transistor SEL can output the pixel signal of pixel P to the signal line VSL. It should be noted that the transistor SEL can be electrically connected in series between the power supply line to which the power supply voltage VDD will be supplied and the transistor AMP. Furthermore, the transistor SEL can be omitted if necessary.

[0071] The transistor RST is configured to reset the voltage of the floating diffuser FD. Figure 3 In the example shown, transistor RST is electrically connected to the power line that will supply the power supply voltage VDD, and is configured to reset the charge of pixel P. Transistor RST is a reset transistor.

[0072] The transistor RST can be controlled by the signal SRST to reset the charge accumulated in the floating diffuser FD and reset the voltage of the floating diffuser FD. Figure 3 In the example shown, transistor RST can electrically connect the power line and the floating diffuser FD to each other and discharge the charge accumulated in the floating diffuser FD. It should be noted that transistor RST can also discharge the charge accumulated in the photoelectric conversion section 12 via transistor TRG.

[0073] Pixel control unit 111 of imaging device 1 (see reference) Figure 1 Control signals are supplied to the gates of transistors TRG, SEL, RST, etc. of each pixel P via the control line Lread to make the transistors enter the ON state (conduction state) or OFF state (non-conduction state).

[0074] As an example, the multiple control lines Lread for each pixel row of the imaging device 1 include wiring for transmitting signals STRG to control transistor TRG, wiring for transmitting signals SSEL to control transistor SEL, and wiring for transmitting signals SRST to control transistor RST, etc.

[0075] It should be noted that the readout circuit 20 can be configured to change the conversion efficiency (gain) when converting charge into voltage. For example, the readout circuit 20 may include a switching transistor for setting the conversion efficiency. As an example, the switching transistor is electrically connected between the floating diffuser FD and the transistor RST.

[0076] In the readout circuit 20, the capacitance added to the floating diffuser FD of pixel P is increased by turning on the switching transistor, thereby switching the conversion efficiency. The switching transistor can switch the capacitance connected to the gate of transistor AMP to change the conversion efficiency.

[0077] Transistors TRG, SEL, RST, and switching transistors are controlled to be turned on or off by the pixel control unit 111. The pixel control unit 111 controls the readout circuit 20 of each pixel P, thereby causing each pixel P to output a pixel signal to the signal line VSL. The pixel control unit 111 can perform control to read the pixel signal of each pixel P to the signal line VSL.

[0078] [Composition of the Imaging Device]

[0079] Figure 4 This is a diagram illustrating an example of the planar configuration of an imaging device according to a first embodiment. Figure 4 An example configuration of pixel P in the pixel unit 100 of the imaging device 1 is shown. Pixel P of the imaging device 1 includes a light guide 60 (light guide member) and a filter 25. The light guide 60 is constructed using, for example, a first structure 51 and a second structure 52 as nanostructures (it should be noted that...). Figure 4 Only the first structure 51 of the first structure 51 and the second structure 52 are shown.

[0080] The light guide section 60 (light guide member) includes a first structure 51 and a second structure 52, and is configured to guide incident light to the photoelectric conversion section 12. The light guide section 60 is a light guide element (light guide member) utilizing metamaterial (metasurface) technology. In the imaging device 1, for example, as in... Figure 4 As shown in the example, a light guide 60 is provided for each pixel P or multiple pixels P.

[0081] The filter 25 is configured to selectively transmit light in a specific wavelength range of the incident light. The filter 25 is an RGB color filter, an infrared light filter, etc. The filter 25 is disposed above the photoelectric conversion unit 12 for each pixel P or a plurality of pixels P (i.e., each predetermined number of pixels P).

[0082] The pixel unit 100 of the imaging device 1 includes a plurality of pixels P, which include a pixel Pr (R pixel) having a filter 25 that transmits red (R) light, a pixel Pg (G pixel) having a filter 25 that transmits green (G) light, and a pixel Pb (B pixel) having a filter 25 that transmits blue (B) light. In the pixel unit 100, the plurality of pixels Pr, the plurality of pixels Pg, and the plurality of pixels Pb are repeatedly arranged.

[0083] Pixels Pr, Pg, and Pb are configured, for example, according to a Bayer arrangement. In pixel section 100, a 2 × 2 pixel arrangement is repeated, comprising one pixel Pr, two pixels Pg, and one pixel Pb. Pixel section 100 includes, for example, pixel rows alternating between pixels Pg and Pr, and pixel rows alternating between pixels Pb and Pg.

[0084] Pixels Pr, Pg, and Pb in pixel unit 100 can generate pixel signals with R, G, and B components, respectively. Imaging device 1 is able to acquire RGB pixel signals. It should be noted that the configuration of pixel P is not limited to the above example, and the configuration can be set arbitrarily.

[0085] For example, pixels Pr can be configured in units of 2 × 2 pixels, pixels Pg can be configured in units of 2 × 2 pixels, and pixels Pb can be configured in units of 2 × 2 pixels. In the pixel unit 100, as an example, four adjacent pixels Pr, four adjacent pixels Pg, and four adjacent pixels Pb can be repeatedly configured. It can be said that the two rows and two columns of pixels Pr, the two rows and two columns of pixels Pg, and the two rows and two columns of pixels Pb are periodically configured.

[0086] The color filter 25 set for pixel P of pixel unit 100 is not limited to a primary color system (RGB) color filter, but can also be a complementary color system color filter such as Cy (cyan), Mg (magenta), or Ye (yellow). A filter corresponding to W (white) can be set, that is, a filter that transmits light in all wavelength regions of the incident light. Filter 25 can be a filter that transmits infrared light.

[0087] It should be noted that in the imaging device 1, the filter 25 may be omitted as needed. For example, depending on the characteristics of the light guide 60, the filter 25 may not be provided for some or all of the pixels P of the imaging device 1. Furthermore, for example, the filter 25 may not be provided for pixels that receive white (W) light to perform photoelectric conversion.

[0088] Figure 5 This is a diagram illustrating an example of the cross-sectional configuration of an imaging device according to a first embodiment. (See diagram for example.) Figure 5 As shown, the imaging device 1 includes, for example, an optical layer 80, an insulating layer 90, a filter 25, a semiconductor layer 10, and a multilayer wiring layer 95. The imaging device 1 has a configuration in which the optical layer 80, insulating layer 90, filter 25, semiconductor layer 10, and multilayer wiring layer 95 are stacked in the Z-axis direction. The optical layer 80, insulating layer 90, the layer with the filter 25, semiconductor layer 10, and multilayer wiring layer 95 are disposed from the side where light is incident.

[0089] The optical layer 80 includes a multi-layer (multi-level) structure and is configured to guide incident light to the photoelectric conversion unit 12. The optical layer 80 includes multiple structures arranged to be stacked on top of each other. Figure 5 The optical layer 80 includes, for example, a first layer 71 (first layer) having the first structure 51 and a second layer 72 (second layer) having the second structure 52. The optical layer 80, including the first layer 71 and the second layer 72, is configured to be stacked on the insulating layer 90.

[0090] Optical layer 80 is an optical element (optical component) utilizing metamaterial (metasurface) technology. Optical layer 80 may also be referred to as a metasurface layer (or metamaterial layer). Both the first structure 51 and the second structure 52 have, for example, a columnar shape. The first structure 51 and the second structure 52 may also be referred to as a first metasurface element and a second metasurface element, respectively.

[0091] The first layer 71 includes a plurality of first structures 51 and a medium (first member 61) disposed around the first structures 51. Furthermore, the second layer 72 includes a plurality of second structures 52 and a medium (second member 62) disposed around the second structures 52. The second layer 72 is configured to be stacked on top of the first layer 71. Each of the first structures 51 and the second structures 52 is, for example, a pillar (columnar member) and may be referred to as a nanopillar.

[0092] The first structure 51 and the first component 61 comprise materials with different refractive indices. Furthermore, the second structure 52 and the second component 62 comprise materials with different refractive indices. (As in...) Figure 5 As shown in the example, for each pixel P or multiple pixels P, the optical layer 80 may include a light guide 60 having a first structure 51, a first component 61, a second structure 52, and a second component 62.

[0093] like Figure 5 As shown, the semiconductor layer 10 has surfaces 11S1 and 11S2 that are opposite to each other. Surface 11S2 is the surface opposite to surface 11S1. Surface 11S1 of the semiconductor layer 10 is a light-receiving surface (light-incident surface). Surface 11S2 of the semiconductor layer 10 is a device forming surface on which elements such as transistors are formed. Surface 11S2 of the semiconductor layer 10 is provided with a gate electrode, a gate insulating film (e.g., a gate oxide film), etc.

[0094] Semiconductor layer 10 includes a semiconductor substrate, such as a silicon (Si) substrate. Semiconductor layer 10 can be a silicon insulator (SOI) substrate, a silicon germanium (SiGe) substrate, a silicon carbide (SiC) substrate, etc. Semiconductor layer 10 can contain a III-V compound semiconductor material, or it can be formed using any other semiconductor material.

[0095] exist Figure 5 In the example shown, the filter 25, insulating layer 90, etc., are disposed on the surface 11S1 side of the semiconductor layer 10. The optical layer 80, filter 25, etc., are stacked on the semiconductor layer 10 in a thickness direction orthogonal to the surface 11S1 of the semiconductor layer 10. The multilayer wiring layer 95 is disposed on the surface 11S2 side of the semiconductor layer 10. The optical layer 80 is disposed on the side where light from the optical system is incident, and the multilayer wiring layer 95 is disposed on the side opposite to the side where light is incident. The imaging device 1 is a so-called back-illuminated imaging device.

[0096] In the semiconductor layer 10, a plurality of photoelectric conversion units 12 (e.g., photoelectric conversion elements) are disposed along surfaces 11S1 and 11S2 of the semiconductor layer 10. For example, the plurality of photoelectric conversion units 12 are formed to be embedded in the semiconductor layer 10. The photoelectric conversion units 12 are disposed between surfaces 11S1 and 11S2 of the semiconductor layer 10. The photoelectric conversion units 12 perform photoelectric conversion on light incident through the optical layer 80, the insulating layer 90, and the filter 25. The photoelectric conversion units 12 may also be referred to as a photoelectric conversion layer.

[0097] A multilayer wiring layer 95 is configured to be stacked on the semiconductor layer 10. The multilayer wiring layer 95 includes, for example, a conductive film and an insulating film, and includes multiple wirings, vias (VIAs), etc. The multilayer wiring layer 95 has a configuration in which multiple wirings are separated by insulating film layers serving as interlayer insulating films (e.g., interlayer insulating layers). The multilayer wiring layer 95 includes, for example, two or more wiring layers or three or more wiring layers.

[0098] The wiring of the multilayer wiring layer 95 is formed using metallic materials such as aluminum (Al), copper (Cu), or tungsten (W). It should be noted that the wiring of the multilayer wiring layer 95 can be constructed using polysilicon (Poly-Si) or any other conductive material. The interlayer insulating film is formed using materials such as silicon oxide (e.g., SiO), silicon nitride (e.g., SiN), and silicon oxynitride (e.g., SiON).

[0099] Semiconductor layer 10 and multilayer wiring layer 95, for example, are provided with the above-mentioned readout circuit 20 for each pixel P or multiple pixels P (see reference). Figure 3 Furthermore, the aforementioned pixel control unit 111, signal processing unit 112, control unit 113, processing unit 114, etc. (see reference) Figure 1 It can be formed in a substrate different from the semiconductor layer 10, or it can be formed in the semiconductor layer 10 and the multilayer wiring layer 95.

[0100] An insulating layer 90 is disposed between the optical layer 80, where the light guide portion 60 is located, and the semiconductor layer 10. Figure 5 In the example shown, the insulating layer 90 is formed stacked on the layer where the filter 25 is disposed. As an example, the insulating layer 90 is constructed using an insulating film such as an oxide film, a nitride film, or an oxynitride film. The insulating layer 90 is formed using an insulating material such as silicon oxide (e.g., SiO), silicon nitride (e.g., SiN), or silicon oxynitride (e.g., SiON).

[0101] The insulating layer 90 may comprise a material with a low refractive index, such as silicon oxide, or may comprise any other material that transmits light in the region of the wavelength to be measured. The insulating layer 90 may also be referred to as a light-transmitting transparent layer or a spacer layer. It should be noted that the optical layer 80 may comprise the insulating layer 90.

[0102] like Figure 5 As shown, the imaging device 1 includes a separation section 30. The separation section 30 is disposed between a plurality of photoelectric conversion sections 12 that are adjacent to each other, so as to separate the photoelectric conversion sections 12 from each other. At least a portion of the separation section 30 is disposed at the boundary between adjacent pixels P (or photoelectric conversion sections 12). The separation section 30 is constructed using, for example, a trench.

[0103] The separation portion 30 is configured to surround the photoelectric conversion portion 12 of each pixel P in the semiconductor layer 10. The separation portion 30 may be configured to penetrate the semiconductor layer 10. In other words, the separation portion 30 may be formed to reach the surface 11S2 of the semiconductor layer 10. The separation portion 30 may also be referred to as a pixel separation portion or pixel separation wall.

[0104] An insulating film, such as a silicon oxide (e.g., SiO) film, a silicon nitride (e.g., SiN) film, or an aluminum oxide (e.g., AlO) film, is disposed within the trench of the separation section 30. The trench of the separation section 30 may be filled with polycrystalline silicon, a metallic material, or any other insulating material. The separation section 30 may be constructed using a semiconductor region (p-type semiconductor region or n-type semiconductor region) formed by ion implantation.

[0105] The separation portion 30 can be formed using any other insulating material with a low refractive index. For example, an air gap (cavity) can be provided within the groove of the separation portion 30. In the imaging apparatus 1, the separation portion 30 suppresses charge leakage generated by photoelectric conversion of the photoelectric conversion unit 12 of pixel P to surrounding pixels P (or photoelectric conversion unit 12). Furthermore, unwanted light leakage to surrounding pixels P can be suppressed, thereby suppressing, for example, color mixing.

[0106] The imaging device 1 may include at least one of a fixed charge film or an anti-reflective film on the surface 11S1 side of the semiconductor layer 10. As an example, both the fixed charge film and the anti-reflective film contain a metal compound (e.g., a metal oxide or a metal nitride) and may also be referred to as a metal compound layer.

[0107] For example, a fixed-charge film and an anti-reflective film are disposed between the semiconductor layer 10 and the filter 25. The fixed-charge film is a film with a fixed charge and can be formed using a material with a high dielectric constant. As an example, the fixed-charge film contains metal oxides such as hafnium oxide (HfO) or aluminum oxide (AlO). The fixed-charge film can also be, for example, a film with a negative fixed charge.

[0108] In the imaging apparatus 1, a fixed-charge film is provided to suppress the generation of dark current at the interface of the semiconductor layer 10. It should be noted that the fixed-charge film can be constructed using any other metal oxide film, or it can be constructed using a metal nitride film or a metal oxynitride film. As the fixed-charge film, a film with a positive fixed charge can be provided.

[0109] As an example, the antireflective film comprises a metal oxide such as hafnium oxide (HfO) or tantalum oxide (Ta). The antireflective film is disposed on the surface 11S1 of the semiconductor layer 10 and reduces (suppresses) reflection. For example, the antireflective film is configured to be stacked on a fixed charge film. It should be noted that the antireflective film can be constructed using insulating materials such as silicon nitride (e.g., SiN), silicon oxide (e.g., SiO), or aluminum oxide (e.g., AlO), or any other material.

[0110] As in Figure 5 As shown in the example, the optical layer 80 of the imaging device 1 is disposed above the photoelectric conversion unit 12. The optical layer 80 includes a first layer 71 having a first structure 51 and a second layer 72 having a second structure 52. The second layer 72 is stacked on the first layer 71. The light guide portion 60 of the optical layer 80 includes the first structure 51 in the first stage and the second structure 52 in the second stage.

[0111] Light from the subject under test enters the light guide section 60. For example, light passing through an optical system such as an imaging lens enters the first structure 51 and the second structure 52 of the light guide section 60. Each of the first structure 51 and the second structure 52 is a structure with a size smaller than or equal to a predetermined wavelength of the incident light.

[0112] The optical layer 80 (or light guide 60) includes a first structure 51 and a second structure 52 as nanostructures, and is configured to guide light from the optical layer 80 to the optical layer 60. Figure 5 The light incident from above is guided to the photoelectric conversion unit 12. Each of the first structure 51 and the second structure 52 has a size smaller than or equal to the wavelength region of the light to be measured, for example, smaller than or equal to the wavelength region of visible light. It should be noted that each of the first structure 51 and the second structure 52 may have a size smaller than or equal to the wavelength region of infrared light.

[0113] Each of the first structure 51 and the second structure 52 is, for example, a columnar (pillar-shaped) structure. As an example, each of the first structure 51 and the second structure 52 has a cylindrical shape. Multiple first structures 51 are arranged side by side in the X-axis direction (or Y-axis direction), with a portion of the first member 61 between them.

[0114] Furthermore, multiple second structures 52 are arranged side-by-side in the X-axis direction (or Y-axis direction), with a portion of the second member 62 interposed therebetween. It should be noted that the shape of each of the first structure 51 and the second structure 52 is adaptable and can be circular or rectangular in plan view. The shape of each of the first structure 51 and the second structure 52 can be elliptical, polygonal, cross-shaped, or any other shape.

[0115] The first member 61 is configured to fill the area around the first structure 51. For example, the first member 61 is formed to fill the area between a plurality of adjacent first structures 51 in the first layer 71. The second member 62 is configured to fill the area around the second structure 52. For example, the second member 62 is formed to fill the area between a plurality of adjacent second structures in the second layer 72.

[0116] A first structure 51 is disposed within a first member 61, and can be said to be configured to replace a portion of the first member 61. Furthermore, a second structure 52 is disposed within a second member 62, and can be said to be configured to replace a portion of the second member 62. It should be noted that the first member 61 and the second member 62 may also be referred to as a dielectric layer or a protective layer (e.g., a protective member).

[0117] The light guide 60 uses a first structure 51 and a second structure 52, which are nanostructures, to propagate light to the photoelectric conversion unit 12. Each of the first structure 51 and the second structure 52 may also be referred to as a metaatom, nanoatom, nanopillar, metasurface structure, microstructure, etc. The light guide 60 is an optical element (e.g., an optical component) that guides (propagates) light.

[0118] The light guide portion 60 is configured, for example, to induce a phase delay in the incident light and to act as a light guiding element. In the optical layer 80, a plurality of first structures 51 and a plurality of second structures 52 are configured to provide a desired phase distribution to the incident light. For example, the size, number, and spacing of the first structures 51 and the second structures 52 are determined to focus light of the wavelength band to be detected onto the photoelectric conversion portion 12.

[0119] Figure 6A and Figure 6B This is a diagram showing an example of the planar configuration of the light guide portion of the imaging device according to the first embodiment. Figure 6A An example of the configuration of the second layer 72 is shown. Figure 6B The following is a structural example of the first layer 71. As an example, as in... Figure 6A and Figure 6B As shown in the example, multiple first structures 51 and multiple second structures 52 are arranged in two dimensions in the X-axis and Y-axis directions in the plan view.

[0120] The width of the first structure 51 in the X-axis direction (or Y-axis direction) and the width of the second structure 52 in the X-axis direction (or Y-axis direction) can both be less than or equal to the wavelength region of visible light. As an example, Figure 6A The width (diameter) W2 of the second structure 52 shown can be 80 nm to 800 nm. Furthermore, as an example, Figure 6B The width W1 of the first structure 51 shown can be 80 nm to 800 nm.

[0121] In the first layer 71 of the imaging device 1, a plurality of first structures 51 are arranged at intervals less than or equal to a predetermined wavelength of incident light. Furthermore, in the second layer 72, a plurality of second structures 52 may be arranged at intervals less than or equal to a predetermined wavelength of incident light. As an example, the plurality of first structures 51 (or the plurality of second structures 52) are arranged at intervals in the X-axis and Y-axis directions at wavelengths less than or equal to those of infrared light.

[0122] In imaging device 1, as in Figure 5 As shown in the example, the second structure 52 is configured to contact the first structure 51. For example, some of the multiple second structures 52 in the second layer 72 are configured to contact the first structure 51. Figure 5 In the example shown, some second structures 52 are disposed on and in contact with the first structure 51.

[0123] It should be noted that, as used herein, the phrase "contact" includes both direct contact and contact through a natural oxide film. The phrase "second structure 52 in contact with first structure 51" includes both the case where a natural oxide film is present between them and the case where second structure 52 is in contact with first structure 51 through a thin natural oxide film. "Contact" indicates that no etch stop film is provided between the structures.

[0124] The first structure 51 and the second structure 52 are configured to be in contact with each other. Figure 5 In the example shown, the upper ends (tops) of some of the first structures 51 are in contact with the lower ends (bottoms) of the second structures 52. The imaging device 1 has a stacked structure of the first structures 51 and the second structures 52. The light guide portion 60 may have a structure in which the second structures 52 are directly stacked on top of the first structures 51.

[0125] Furthermore, in the imaging device 1, the first component 61 and the second component 62 are arranged to be in contact with each other. For example, as in... Figure 5 As shown in the example, the second member 62 is configured to contact the first member 61. The second member 62 is directly stacked on the first member 61 and is configured to contact the first member 61.

[0126] The refractive index of the first structure 51 is different from that of the adjacent medium. Figure 5 In the example shown, the refractive index of the first structure 51 is different from the refractive index of the first member 61. The refractive index of the first structure 51 is different from the refractive index of the medium surrounding the first structure 51 (i.e., the first member 61). It should be noted that the first member 61 can also be referred to as a first material layer with a refractive index different from that of the first structure 51.

[0127] The refractive index of the second structure 52 differs from that of the adjacent medium. Figure 5 In the example shown, the refractive index of the second structure 52 is different from the refractive index of the second member 62. The refractive index of the second structure 52 is different from the refractive index of the medium surrounding the second structure 52 (i.e., the second member 62). The second member 62 can also be referred to as a second material layer with a refractive index different from that of the second structure 52.

[0128] The refractive index of the first structure 51 is, for example, higher than that of the first member 61. The first structure 51 may contain a material with a refractive index higher than that of the first member 61. Furthermore, the refractive index of the second structure 52 is, for example, higher than that of the second member 62. The second structure 52 may contain a material with a refractive index higher than that of the second member 62.

[0129] The first structure 51 and the second structure 52 are constructed using different materials. The second structure 52, for example, is formed on the first structure 51 and has a refractive index different from that of the first structure 51. For example, the refractive index of the second structure 52 is lower than that of the first structure 51. The second structure 52 may contain a material with a refractive index lower than that of the first structure 51.

[0130] It should be noted that the refractive index of the second structure 52 may be higher than that of the first structure 51. The second structure 52 may contain a material with a refractive index higher than that of the first structure 51. The first structure 51 and the second structure 52 may be constructed using, for example, inorganic materials.

[0131] As an example, the first structure 51 is constructed using titanium oxide (TiO). Furthermore, as an example, the second structure 52 is constructed using silicon nitride (SiN). The first structure 51 and the second structure 52 can be formed using silicon, polycrystalline silicon (Poly-Si), amorphous silicon (a-Si), germanium (Ge), etc.

[0132] The first structure 51 and the second structure 52 may contain elements, oxides, nitrides, or oxynitrides of titanium (Ti), hafnium (Hf), zirconium (Zr), aluminum (Al), tantalum (Ta), indium (In), niobium (Nb), etc., or their complexes. The first structure 51 and the second structure 52 may contain any other metal compound (e.g., metal oxide or metal nitride).

[0133] Furthermore, the first structure 51 and the second structure 52 can be constructed using GaP, GaN, GaAs, SiC, etc. The first structure 51 and the second structure 52 can be formed using silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, or any other silicon compound. The first structure 51 and the second structure 52 can be constructed using materials that are different from each other.

[0134] The first component 61 and the second component 62 are constructed using the same material. As an example, the first component 61 and the second component 62 are constructed using inorganic materials such as oxides, nitrides, or oxynitrides. The first component 61 and the second component 62 can be formed using, for example, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbide, or any other silicon compound. The first component 61 and the second component 62 can be constructed using TEOS.

[0135] The first component 61 and the second component 62 can be made of the same organic material. The first component 61 and the second component 62 can be made of siloxane-based resins, styrene-based resins, acrylic resins, etc. The first component 61 and the second component 62 can contain a fluorine-containing material in any of these resins. The first component 61 and the second component 62 can be formed using a material filled with beads (fillers) of a refractive index higher than (or lower than) the refractive index of the resin in any of these resins.

[0136] The materials of the first structure 51, the second structure 52, the first component 61, and the second component 62 can be selected based on the refractive index difference with the surrounding medium, the wavelength region of the incident light to be measured, etc. It should be noted that the first structure 51, the second structure 52, the first component 61, and the second component 62 can be partially constructed using air. For example, the first structure 51 can contain air (e.g., an air gap).

[0137] The light guide portion 60 of the optical layer 80 causes a phase delay of the incident light due to the refractive index difference between the first structure 51 and the second structure 52 and the surrounding medium, thereby allowing control of the wavefront. The light guide portion 60 provides phase delay to the incident light through, for example, the second structure 52 and the second member 62, as well as the first structure 51 and the first member 61, which allows adjustment of the direction of light propagation.

[0138] The materials (optical constants of each material) of the first structure 51, the second structure 52, the first member 61, and the second member 62, the dimensions (e.g., width (diameter) and height) of the first structure 51 and the second structure 52, the spacing (e.g., configuration interval), etc., are determined to allow light from the incident light from the object being measured, including any wavelength region, to propagate in the desired direction. For example, the materials (refractive index), dimensions, and spacing of the first structure 51 and the second structure 52, the materials (refractive index) of the first member 61 and the second member 62, etc., can be set.

[0139] As an example, in imaging apparatus 1, the material, size, number of arrangements, etc. of the first structure 51 and the second structure 52 of each pixel P are determined to allow light of a specific wavelength band to be detected to propagate to the photoelectric conversion section 12 of the desired pixel P. For example, the first structure 51 and the second structure 52 of the light guide sections 60 of pixels Pr, Pg, and Pb can be formed to have different dimensions (e.g., width and height), different arrangement positions, etc.

[0140] The optical layer 80 (or light guide 60) can be configured as a beam splitter (beam splitting element) to disperse incident light. The optical layer 80 (or light guide 60) can also be referred to as a beam splitter (e.g., a color beam splitter). The optical layer 80 can also be referred to as a beam splitter layer or a wavelength separation layer. The optical layer 80 (or light guide 60) can also be referred to as an optical element configured to redirect light.

[0141] As in Figure 5 As shown in the example, the light guide portion 60 of the imaging device 1 may include an antireflective film 45 and a blocking film 46. The antireflective film 45 (e.g., a reflection suppression film) is disposed on the light incident side of the second structure 52 and is located on the second structure 52. For example, as Figure 5 As shown, the antireflective film 45 is configured to cover a plurality of second structures 52 and reduce (e.g., suppress) reflection.

[0142] The antireflective film 45 is constructed using silicon compounds such as silicon nitride (e.g., SiN) or silicon oxide (e.g., SiO). It should be noted that the antireflective film 45 can be constructed using metal compounds or any other material. The antireflective film 45 can be constructed by stacking multiple films.

[0143] For example, a stop film 46 is disposed between the first structure 51 and the insulating layer 90. When manufacturing the imaging device 1, the stop film 46 serves as an etching stop film (e.g., a stop layer). The provision of the stop film 46 improves the process controllability of the first structure 51. The stop film 46 may also be referred to as an etching prevention film (e.g., an etching suppression film).

[0144] The barrier film 46 comprises, for example, a single-layer film containing one of silicon nitride (SiN), silicon oxynitride (SiON), hafnium oxide (HfO), aluminum oxide (AlO), etc., or a multilayer film containing two or more of them. The barrier film 46 can be formed using any other material. It should be noted that the insulating layer 90 may include the barrier film 46.

[0145] As described above, light from the subject under test enters each pixel P of the imaging device 1 via the optical layer 80. Each pixel P can receive light incident via the second structure 52 and the first structure 51 of the light guide 60 and generate a pixel signal. The imaging device 1 can use the pixel signals obtained by photoelectric conversion in each pixel P to generate image data representing an image of the subject.

[0146] Furthermore, for example, the imaging device 1 can use the pixel signals of each pixel to generate image data related to the distance to the object (e.g., distance image data). In this embodiment, the light guide portion 60, including the first structure 51 and the second structure 52, allows light to be appropriately guided to the photoelectric conversion portion 12. This can improve the sensitivity to incident light.

[0147] In the imaging device 1, as described above, the first structure 51 is positioned in contact with the second structure 52. This allows for the suppression of unwanted reflected light and improves quantum efficiency (QE). Compared to the case where an etch stop film is provided between the first structure 51 and the second structure 52, the number of interfaces can be reduced and an increase in reflectivity can be prevented.

[0148] In the imaging device 1, the second structure 52 is positioned in contact with the first structure 51, which suppresses the generation of unwanted reflected light and prevents a decrease in light utilization efficiency. This improves sensitivity to incident light. Furthermore, it suppresses the occurrence of light spots and prevents a degradation in image quality.

[0149] Furthermore, in this embodiment, the first structure 51 and the second structure 52 are constructed using different materials. The light guide section 60 includes the first structure 51 and the second structure 52, which contain different materials, allowing for fine adjustment of the phase retardation of light in each wavelength region. Light in any wavelength region can be appropriately guided to the photoelectric conversion section 12. A light detection device with excellent optical characteristics can be realized.

[0150] The first structure 51 has, for example, a refractive index n1, and the second structure 52 has, for example, a refractive index n2. The first structure 51 and the second structure 52 can be configured to satisfy n1 > n2. A gradual change in refractive index from the air (e.g., an air layer) above the imaging device 1 to the first structure 51 can be achieved. This makes it possible to reduce light loss.

[0151] It should be noted that the first structure 51, the second structure 52, and the antireflective film 45 can be configured to satisfy n1 > n2 > n3, where n3 represents the refractive index of the antireflective film 45. This allows for adjustment of the reflectivity on the light guide portion 60 and improves light utilization efficiency.

[0152] Figure 7 This is an explanatory diagram of another configuration example of the imaging device 1 according to the first embodiment. Furthermore, Figure 8 This is an explanatory diagram of another configuration example of the light guide portion 60 of the imaging device 1. The optical layer 80, light guide portion 60, etc. of the imaging device 1 may have Figure 7 and Figure 8 The configuration is shown. The first structure 51 and the second structure 52 can have different shapes from each other.

[0153] As in Figure 7 or Figure 8 As shown in the example, the first structure 51 can be configured such that the width (length) of the first structure 51 on the side of the second structure 52 is greater than the width of the first structure 51 on the side opposite to the second structure 52. The first structure 51 can be formed such that the width of the upper end (e.g., top) of the first structure 51 is greater than (e.g., thicker) the width of the lower end (bottom) of the first structure 51.

[0154] For example, the width of the first structure 51 in the X-axis direction (or Y-axis direction) increases as the distance to the second structure 52 decreases. In other words, the width (e.g., thickness) of the first structure 51 in the X-axis direction (or Y-axis direction) decreases as the distance to the barrier film 46 (or insulating layer 90) decreases.

[0155] The width (e.g., length) of the first structure 51 in the X-axis direction (or Y-axis direction) can monotonically increase within a predetermined range (e.g., a range) according to the distance from the barrier membrane 46. Figure 7 In the example shown, the width of the first structure 51 gradually increases (e.g., thickens) from bottom to top. It can be said that the first structure 51 has a portion whose width gradually increases (e.g., thickens) as the distance to the second structure 52 decreases.

[0156] As in Figure 7 or Figure 8 As shown in the example, the second structure 52 can be configured such that the width (e.g., length) of the second structure 52 on the side of the first structure 51 is greater than the width of the second structure 52 on the opposite side of the first structure 51. The second structure 52 can be formed such that the width of the lower end (e.g., bottom) of the second structure 52 is greater than (e.g., thicker) the width of the upper end (e.g., top) of the second structure 52.

[0157] For example, the width of the second structure 52 in the X-axis direction (or Y-axis direction) gradually increases as the distance to the first structure 51 decreases. In other words, the width (e.g., thickness) of the second structure 52 in the X-axis direction (or Y-axis direction) decreases as the distance to the antireflective film 45 decreases.

[0158] The width (e.g., length) of the second structure 52 in the X-axis direction (or Y-axis direction) can monotonically increase within a predetermined range (e.g., a range) according to the distance from the antireflective film 45. Figure 7 In the example shown, the width of the second structure 52 gradually increases (e.g., thickens) from top to bottom. It can be said that the second structure 52 has a portion whose width gradually increases (e.g., thickens) as the distance to the first structure 51 decreases.

[0159] The first structure 51 and the second structure 52 may have different shapes from each other. As mentioned above, the first structure 51 and the second structure 52 have, for example, different conical shapes. As an example, the first structure 51 has an inverted conical shape. Furthermore, the second structure 52 has a regular conical shape.

[0160] As in Figure 7 or Figure 8 As shown in the example, the first structure 51 may have a recess 55. The first structure 51 may have a recess 55 (e.g., a groove) disposed on the side of the second structure 52. For example, the first structure 51 with the recess 55 can be formed using photolithography and etching. The recess 55 may also be referred to as a depression (e.g., a groove).

[0161] like Figure 7 or Figure 8 As schematically shown, a recess 55 may be provided on the top of the first structure 51. The recess 55 may be formed as a relatively shallow portion and may also be referred to as a depression. The depth (e.g., height) of the recess 55 may be less than or equal to a few nm. As an example, Figure 8 The depth d1 of the recess 55 shown can be about 5 nm.

[0162] The second structure 52 can be configured to contact the recess 55 of the first structure 51. Figure 7 and Figure 8 In the example shown, a portion of the second structure 52 is disposed within the recess 55 of the first structure 51. For example, a portion of the second structure 52 is configured to be embedded in the recess 55.

[0163] The thickness (e.g., height) of the first structure 51 in the Z-axis direction can be less than or equal to several hundred nm, or less than or equal to tens of nm. The thickness (e.g., length) d11 in the Z-axis direction can be 10 nm to 2000 nm. Furthermore, as an example, the thickness d12 of the second structure 52 in the Z-axis direction can be 10 nm to 2000 nm. The film thickness d13 of the antireflective film 45 can, for example, be in the range of 10 nm to 3000 nm. Furthermore, the film thickness d14 of the blocking film 46 can, for example, be 1 nm to 1000 nm.

[0164] In the imaging device 1, the light guide portion 60 includes a first structure 51 and a second structure 52 with different shapes, which improves the controllability of light. Furthermore, it increases design flexibility. As described above, providing the first structure 51 and the second structure 52 with different conical shapes reduces reflections on the light guide portion 60.

[0165] In the optical layer 80 of the imaging device 1, a first structure 51 and a second structure 52 with different conical shapes are stacked on top of each other. This improves the adhesion between the first layer 71 and the second layer 72. Furthermore, by placing a portion of the second structure 52 within a recess 55 of the first structure 51, the adhesion between the second structure 52 and the first structure 51 is further improved. This enhances the reliability of the imaging device 1.

[0166] Furthermore, in the imaging apparatus 1 according to this embodiment, the second structure 52 in the second stage can have a seamless configuration, which allows for the suppression of light scattering in the light guide 60. This reduces light loss and suppresses the decrease in light detection accuracy.

[0167] Figures 9A-9D These are all explanatory diagrams illustrating an example of a method for manufacturing the light guide portion of the imaging device according to the first embodiment. Firstly, as... Figure 9A As shown, a material film 102 (e.g., a silicon nitride (SiN) film) is formed on the first structure 51 and the first member 61 as the material of the second structure 52. Thereafter, as... Figure 9B As shown, a resist film 105 is formed on the material film 102 by photolithography and etching.

[0168] Next, dry etching is performed on the resist film 105 and the material film 102. For example... Figure 9C As shown, this removes excess portions of the material film 102, thereby forming the second structure 52. Subsequently, as... Figure 9D As shown, a second component 62 is formed on the first layer 71, and chemical mechanical polishing (CMP) is performed to form the second layer 72.

[0169] Subsequently, an anti-reflective film 45 is formed on the second structure 52 and the second component 62. The manufacturing method described above allows for the manufacture of... Figure 7 The light guide portion 60 is shown in the figure. It should be noted that the above manufacturing method is merely exemplary, and other manufacturing methods may be used.

[0170] [Functions and Effects]

[0171] The photodetector according to this embodiment includes a first layer (first layer 71), a second layer (second layer 72) stacked on the first layer, and a photoelectric conversion element (photoelectric conversion section 12). The first layer includes a plurality of first structures (e.g., first structures 51) arranged side-by-side in a first direction (e.g., the X-axis direction) and a first medium (first member 61) disposed around the first structures and having a refractive index different from that of the first structures. The second layer includes a plurality of second structures (second structures 52) arranged side-by-side in the first direction and a second medium (second member 62) disposed around the second structures and having a refractive index different from that of the second structures. The photoelectric conversion element performs photoelectric conversion on light incident via the second layer and the first layer. The first and second structures contain materials different from each other. The first structure is in contact with the second structure.

[0172] In the light detection apparatus (imaging apparatus 1) according to this embodiment, a first layer 71 including a first structure 51 and a second layer 72 including a second structure 52 are provided. The first structure 51 is in contact with the second structure 52. This allows the generation of unwanted reflected light to be suppressed. A light detection apparatus that allows for improved characteristics for incident light can be realized.

[0173] <2. Second Implementation Plan>

[0174] Next, a description of a second embodiment of this disclosure will be given. The technology according to this disclosure is applicable to various electronic devices, optical devices, etc. The light guide portion 60 (or optical layer 80) constructed using the above-described nanostructure is suitable for various optical elements (e.g., optical components). In the following, components similar to those in the above-described embodiments are indicated by the same reference numerals, and their descriptions are appropriately omitted.

[0175] Figure 10 and Figure 11 These are all explanatory diagrams illustrating an example of the configuration of an optical element according to the second embodiment of this disclosure. The optical element 200 includes a substrate 120 and an optical layer 80. The optical layer 80 has a first layer 71 including a plurality of first structures 51 and a second layer 72 including a plurality of second structures 52. The optical element 200 is an optical element (optical component) constructed using the first structures 51 and the second structures 52 as nanostructures, and can be configured as a superlens (metamaterial lens).

[0176] Substrate 120 is a light-transmitting substrate (transparent substrate) and includes, for example, a glass substrate. As an example, substrate 120 (e.g., a base material) may contain a material with a refractive index lower than that of the first structure 51 (or the second structure 52). Substrate 120 may contain, for example, quartz glass, borosilicate glass, or may contain a resin substrate. Substrate 120 (e.g., a base material) may contain any other material that transmits the light to be measured.

[0177] like Figure 10 As shown, the substrate 120 has surfaces 12S1 and 12S2 that are opposite to each other. Surface 12S2 is the surface opposite to surface 12S1. An optical layer 80 is disposed on the light incident side of the substrate 120. Figure 10 or Figure 11 In the example shown, an optical layer 80 including a plurality of first structures 51 and a plurality of second structures 52 is formed on the surface 12S1 of the substrate 120.

[0178] The optical layer 80, including the first structure 51 and the second structure 52, can be disposed on opposite sides of the light incident side of the substrate 120 (i.e., on the light emitting side). The optical layer 80 can be stacked on the substrate 120 on either the light incident side or the light emitting side, separated by an insulating layer. It should be noted that the shape of the substrate 120 is not particularly limited and can be circular, rectangular, or any other shape.

[0179] As in Figure 11 As shown in the example, the first structure 51 and the second structure 52 can each have a conical shape. Furthermore, the first structure can have a recess 55. A portion of the second structure 52 can be configured to contact the recess 55 of the first structure 51. It should be noted that the shape, number, etc., of the first structure 51 and the second structure 52 are not limited to the example shown and can be appropriately varied.

[0180] Optical element 200 can be configured as, for example, a lens, such as a lens that converges or disperses light. Optical element 200 can be configured as a beam splitter that disperses incident light, a filter that transmits light in a specific wavelength region, a deflector that changes the direction of light propagation, etc. Optical element 200 can be configured as part of the optical system of various devices, for example.

[0181] [Functions and Effects]

[0182] The optical element according to this embodiment includes a first layer (e.g., first layer 71) and a second layer (e.g., second layer 72) stacked on the first layer. The first layer includes a plurality of first structures (e.g., first structure 51) arranged side-by-side in a first direction (e.g., the X-axis direction) and a first medium (first member 61) disposed around the first structures and having a refractive index different from that of the first structures. The second layer includes a plurality of second structures (e.g., second structure 52) arranged side-by-side in the first direction and a second medium (e.g., second member 62) disposed around the second structures and having a refractive index different from that of the second structures. The first and second structures contain different materials from each other. The first structure is in contact with the second structure.

[0183] In the optical element (e.g., optical element 200) according to this embodiment, a first layer 71 including a first structure 51 and a second layer 72 including a second structure 52 are provided. The first structure 51 is in contact with the second structure 52. This allows for improved characteristics of the incident light. An optical element with excellent optical properties can be realized.

[0184] <3. Applicable Examples>

[0185] For example, the imaging device 1 described above can be applied to any type of electronic device with imaging capabilities, including camera systems such as digital cameras or camcorders, and mobile phones with imaging capabilities. Figure 12 A schematic configuration of the electronic device 1000 is shown.

[0186] 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, and they are connected to each other via a bus 1008.

[0187] Lens group 1001 captures incident light (image light) from the subject and forms an image on the imaging surface of imaging device 1. Imaging device 1 converts the amount of incident light that has formed an image on the imaging surface by lens group 1001 into an electrical signal in pixels and supplies it as a pixel signal to DSP circuit 1002.

[0188] 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 supplied from the imaging device 1. The frame memory 1003 temporarily stores the image data processed by the DSP circuit 1002 in units of frames.

[0189] For example, the display unit 1004 includes a panel-type display device such as a liquid crystal panel or an organic electroluminescent (EL) panel, and records image data of moving or still images captured by the imaging device 1 on a recording medium such as a semiconductor memory or a hard disk.

[0190] The operation unit 1006 outputs operation signals for various functions of the electronic device 1000 according to the operation performed by the user. The power supply unit 1007 appropriately supplies various types of power to the DSP circuit 1002, frame memory 1003, display unit 1004, recording unit 1005 and operation unit 1006.

[0191] <4. Application Examples>

[0192] <Examples of applications of moving objects>

[0193] The technology according to the present disclosure (the technology) can be applied to a variety of products. For example, the technology according to the present disclosure is implemented as a device to be installed on any type of mobile body such as a car, electric car, hybrid electric car, motorcycle, bicycle, personal mobility device, airplane, drone, ship or robot.

[0194] Figure 13 This is a block diagram illustrating a schematic configuration example of a vehicle control system, which is an example of a mobile body control system to which the technology is applicable according to the embodiments of this disclosure.

[0195] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 13 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a main system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and a comprehensive control unit 12050. Furthermore, as functional components of the comprehensive control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0196] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 is used as a control device such as a drive force generating device for generating drive force for a vehicle such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting drive force to the wheels, a steering mechanism for adjusting the vehicle's steering angle, and a braking device for generating braking force for the vehicle.

[0197] The main system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the main system control unit 12020 is used as a control device for keyless entry systems, smart key systems, power windows, or various lights such as headlights, taillights, brake lights, turn signals, and fog lights. In this case, radio waves transmitted from a portable device or signals from various switches, used instead of buttons, can be input to the main system control unit 12020. The main system control unit 12020 receives the input radio waves or signals and controls the vehicle's door locking devices, power windows, lights, etc.

[0198] The exterior information detection unit 12030 detects information related to the exterior of the vehicle, including information from the vehicle control system 12000. For example, the exterior information detection unit 12030 is connected to the imaging unit 12031. The exterior information detection unit 12030 causes the imaging unit 12031 to capture images of the exterior of the vehicle and receives the captured images. Based on the received images, the exterior information detection unit 12030 can perform processing such as detecting objects like people, cars, obstacles, signs, and text on the road, or detecting their distance.

[0199] 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 an electrical signal as an image, or it can output an electrical signal as information related to the measured distance. In addition, the light received by the imaging unit 12031 can be visible light, or it can be invisible light such as infrared light.

[0200] The in-vehicle information detection unit 12040 detects information related to the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 that detects the driver's state. For example, the driver state detection unit 12041 includes a camera that captures images of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or determine whether the driver is asleep in a seated position.

[0201] The microcomputer 12051 can calculate control target values ​​for the drive force generating device, steering mechanism, or braking device based on information about the vehicle's interior and exterior obtained by the external information detection unit 12030 or the internal information detection unit 12040, and can output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform coordinated control to implement functions of advanced driver assistance systems (ADAS), including collision avoidance or collision mitigation, following distance-based driving, vehicle speed maintenance, vehicle collision warning, and vehicle lane departure warning.

[0202] In addition, the microcomputer 12051 can coordinate and control the drive force generating device, steering mechanism, braking device, etc., based on information about the exterior or interior of the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, so as to realize autonomous driving, where the vehicle drives itself without relying on the operation of the driver.

[0203] In addition, the microcomputer 12051 can output control commands to the main system control unit 12020 based on information about the vehicle's external environment obtained by the external information detection unit 12030. For example, the microcomputer 12051 controls the headlights according to the position of the vehicle in front or oncoming vehicles detected by the external information detection unit 12030 to perform coordinated control, thereby achieving glare prevention such as switching the high beams to low beams.

[0204] The sound / image output unit 12052 transmits at least one of sound and image output signals to an output device capable of visually or audibly informing vehicle occupants or the outside of the vehicle. Figure 13 In the example, an audio speaker 12061, a display unit 12062, and a dashboard 12063 are shown as output devices. For example, the display unit 12062 may include at least one of an in-vehicle display and a head-up display.

[0205] Figure 14 This is a diagram showing an example of the mounting location of the imaging unit 12031.

[0206] exist Figure 14 In the imaging unit 12031, there are imaging units 12101, 12102, 12103, 12104 and 12105.

[0207] Imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, at the front of vehicle 12100, in the side mirrors, rear bumper, and rear door, as well as on the upper side of the windshield inside the vehicle. Imaging unit 12101 in the front of the vehicle and imaging unit 12105 on the upper side of the windshield inside the vehicle primarily acquire images of the front of vehicle 12100. Imaging units 12102 and 12103 in the side mirrors primarily acquire images of the sides of vehicle 12100. Imaging unit 12104 in the rear bumper or rear door primarily acquires images of the rear of vehicle 12100. Imaging unit 12105 on the upper side of the windshield inside the vehicle is mainly used to detect vehicles, pedestrians, obstacles, traffic signals, traffic signs, lanes, etc., ahead.

[0208] Incidentally, Figure 14 Examples of the imaging ranges of imaging units 12101 to 12104 are shown. Imaging range 12111 represents the imaging range of imaging unit 12101 located at the front of the vehicle. Imaging ranges 12112 and 12113 represent the imaging ranges of imaging units 12102 and 12103 located in the side mirrors, respectively. Imaging range 12114 represents the imaging range of imaging unit 12104 located in the rear bumper or rear door. For example, by superimposing the image data captured by imaging units 12101 to 12104 onto each other, a bird's-eye view of the vehicle 12100 as seen from above is obtained.

[0209] At least one of the imaging units 12101 to 12104 may have the function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of multiple imaging devices, or may be an imaging device having pixels for phase difference detection.

[0210] For example, based on distance information obtained from imaging units 12101-12104, microcomputer 12051 can determine the distance to each three-dimensional object within the imaging range 12111-12114 and the time change of that distance (relative speed relative to vehicle 12100), thereby extracting the three-dimensional object located on the driving path of vehicle 12100, particularly the closest three-dimensional object, that is traveling in approximately the same direction as vehicle 12100 at a predetermined speed (e.g., 0 km / h or more), as the vehicle ahead. Furthermore, microcomputer 12051 can set a pre-determined distance between vehicles in front of the vehicle ahead and can perform automatic braking control (including tracking stop control), automatic acceleration control (including tracking start control), etc. Therefore, coordinated control for autonomous driving, etc., aimed at autonomous vehicle operation without relying on driver operation, is possible.

[0211] For example, based on distance information obtained from imaging units 12101-12104, microcomputer 12051 can classify three-dimensional object data into three-dimensional object data for two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, extract the classified three-dimensional object data, and use the extracted three-dimensional object data to automatically avoid obstacles. For example, microcomputer 12051 identifies obstacles around vehicle 12100 as obstacles that the driver of vehicle 12100 can visually recognize and obstacles that the driver of vehicle 12100 cannot visually recognize. Then, microcomputer 12051 determines the collision risk, indicating the degree of danger of colliding with each obstacle. When the collision risk is equal to or higher than a set value and there is a possibility of collision, microcomputer 12051 outputs a warning to the driver via audio speaker 12061 and display unit 12062, or performs forced deceleration or evasive steering via drive system control unit 12010. Microcomputer 12051 can assist driving to avoid collisions.

[0212] At least one of the imaging units 12101-12104 can be an infrared camera that detects infrared light. For example, the microcomputer 12051 can identify a pedestrian by determining whether a pedestrian exists in the images captured by the imaging units 12101-12104. For example, pedestrian identification is performed by extracting feature points from the images captured by the imaging units 12101-12104, which are infrared cameras, and by performing pattern matching processing on a series of feature points indicating the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101-12104 and thereby identifies the pedestrian, the sound / image output unit 12052 controls the display unit 12062 to display a quadrilateral outline for emphasis, superimposed on the identified pedestrian. The sound / image output unit 12052 can also control the display unit 12062 to display an icon or similar indicating the pedestrian at a desired location.

[0213] Examples of vehicle control systems to which the technology according to embodiments of the present disclosure is applicable have been described above. The technology according to embodiments of the present disclosure can be applied to, for example, the imaging unit 12031 in the above-described configuration. Specifically, for example, imaging device 1, etc., can be applied to the imaging unit 12031. By applying the technology according to embodiments of the present disclosure to the imaging unit 12031, images with high resolution can be obtained. In a mobile body control system, high-precision control can be performed using the images.

[0214] <Examples of the Application of Endoscopic Surgical Systems>

[0215] The technology according to the embodiments of this disclosure can be applied to various products. For example, the technology according to the embodiments of this disclosure can be applied to endoscopic surgical systems.

[0216] Figure 15 This is a diagram illustrating an example of a schematic configuration of an endoscopic surgical system to which the technology (the technology) according to embodiments of the present disclosure can be applied.

[0217] exist Figure 15 The image shows a surgeon (physician) 11131 performing surgery on a patient 11132 on a bed 11133 using an endoscopic surgery system 11000. As shown, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical instruments 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm assembly 11120 supporting the endoscope 11100 thereon, and a trolley 11200 on which various devices for endoscopic surgery are mounted.

[0218] Endoscope 11100 includes a lens tube 11101 having a region at a predetermined distance distal to its end that is inserted into a body cavity of patient 11132, and a camera 11102 connected to the proximal end of the lens tube 11101. In the example shown in the figures, an endoscope 11100 comprising a rigid endoscope with a rigid lens tube 11101 is illustrated. However, endoscope 11100 may also include a flexible endoscope with a flexible lens tube 11101.

[0219] The lens tube 11101 has an opening at its distal end into which an objective lens is fitted. A light source device 11203 is connected to the endoscope 11100, such that light generated by the light source device 11203 is guided through a light guide extending inside the lens tube 11101 to the distal end of the lens tube, and then directed via the objective lens towards the object being observed within the body cavity of the patient 11132. Note that the endoscope 11100 can be a direct-viewing endoscope, or it can be an oblique-viewing endoscope or a side-viewing endoscope.

[0220] An optical system and an imaging device are housed inside the camera 11102, which focuses reflected light (observation light) from the object being observed onto the imaging device via the optical system. The observation light is photoelectrically converted by the imaging device to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is transmitted as RAW data to the camera control unit (CCU) 11201.

[0221] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), etc., and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Furthermore, for example, the CCU 11201 receives image signals from the camera 11102 and performs various types of image processing, such as image processing (de-mosaic processing), to display an image based on the image signal.

[0222] The display device 11202 displays an image based on an image signal that has been image-processed by the CCU 11201 under the control of the CCU 11201.

[0223] For example, the light source device 11203 includes a light source such as a light-emitting diode (LED) and supplies illumination light to the endoscope 11100 when photographing the surgical area.

[0224] Input device 11204 is an input interface for endoscopic surgical system 11000. Users can input various types of information or commands into endoscopic surgical system 11000 via input device 11204. For example, users can input commands to change the imaging conditions of endoscope 11100 (type of illumination light, magnification, focal length, etc.).

[0225] The instrument control device 11205 controls the drive of the energy device 11112 for purposes such as tissue cauterization or incision, and sealing of blood vessels. The pneumoperitoneum device 11206 injects gas into the patient's body cavity 11132 via the pneumoperitoneum tube 11111 to inflate the cavity, ensuring the field of vision of the endoscope 11100 and ensuring the surgeon's working space. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, and graphics.

[0226] Note that, for example, the light source device 11203 supplied to the endoscope 11100 when photographing the surgical area may include an LED, a laser light source, or a combination thereof as a white light source. In the case where the white light source includes a combination of red, green, and blue (RGB) laser light sources, the white balance adjustment of the captured image can be performed by the light source device 11203 because the output intensity and timing of each color (wavelength) can be controlled with high precision. Furthermore, in this case, if lasers from each RGB laser source are emitted onto the object of observation in a time-division manner and the driving of the imaging device of the camera 11102 is controlled in sync with the emission timing, images corresponding to RGB colors can be captured in a time-division manner. According to this method, color images can be obtained even if a color filter is not provided for the imaging device.

[0227] Furthermore, the light source device 11203 can be controlled to change the intensity of the light to be output at various preset intervals. By controlling the driving of the imaging device of the camera 11102 in sync with the timing of the change in light intensity to acquire and synthesize images in time segments, high dynamic range images without underexposed shadows and overexposed highlights can be generated.

[0228] Furthermore, the light source device 11203 can supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in body tissues to emit light with a narrow band compared to the illumination light used in ordinary observation (i.e., white light), narrow band imaging (narrow band imaging) is performed to capture images of predetermined tissues such as blood vessels on the mucosal surface with high contrast. Additionally, in special light observation, fluorescence observation is performed to obtain images from fluorescence generated by emitting excitation light. In fluorescence observation, for example, excitation light can be irradiated onto body tissue to observe fluorescence from the body tissue (autofluorescence observation), or a reagent such as indocyanine green (ICG) can be locally injected into the body tissue and excitation light corresponding to the fluorescence wavelength of the reagent can be emitted to obtain a fluorescence image. The light source device 11203 can supply narrow band light and / or excitation light suitable for the aforementioned special light observation.

[0229] Figure 16It is shown Figure 15 The block diagram shown illustrates an example of the functional configuration of the camera 11102 and CCU 11201.

[0230] Camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. Camera 11102 and CCU 11201 are connected via a transmission cable 11400 for communication with each other.

[0231] Lens unit 11401 is an optical system disposed at the connection point with lens barrel 11101. Observation light received from the distal end of lens barrel 11101 is guided to camera 11102 and incident on lens unit 11401. Lens unit 11401 includes a combination of multiple lenses, including zoom lenses and focal lenses.

[0232] The imaging unit 11402 can include one (single-plate type) or multiple (multi-plate type). When the imaging unit 11402 is configured as a multi-plate type, for example, image signals corresponding to each RGB are generated by the imaging devices, and a color image can be obtained by synthesizing the image signals. Alternatively, the imaging unit 11402 can also be configured to have a pair of imaging devices for acquiring image signals for the right and left eyes for three-dimensional (3D) display. If 3D display is performed, the surgeon 11131 can more accurately grasp the depth of body tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multi-plate type, multiple lens units 11401 are provided corresponding to each imaging device.

[0233] Furthermore, the imaging unit 11402 does not necessarily have to be mounted on the camera 11102. For example, the imaging unit 11402 can be mounted directly behind the objective lens inside the lens barrel 11101.

[0234] The drive unit 11403 includes an actuator, and under the control of the camera control unit 11405, moves the zoom lens and focus lens of the lens unit 11401 a predetermined distance along the optical axis. Therefore, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0235] The communication unit 11404 includes a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits image signals acquired from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0236] Additionally, the communication unit 11404 receives control signals from the CCU 11201 for controlling the camera 11102 and supplies these control signals to the camera control unit 11405. The control signals include information related to imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value during imaging, and / or information specifying the magnification and focus of the captured image.

[0237] Note that imaging conditions such as frame rate, exposure value, magnification, and focus can be appropriately specified by the user, or can be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the automatic exposure (AE) function, automatic focus (AF) function, and automatic white balance (AWB) function are integrated into the endoscope 11100.

[0238] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0239] The communication unit 11411 includes a communication device for transmitting and receiving various types of information to and from the camera 11102. The communication unit 11411 receives image signals transmitted from the camera 11102 via a transmission cable 11400.

[0240] In addition, the communication unit 11411 transmits control signals for controlling the camera 11102 to the camera 11102. Image signals and control signals can be transmitted via electrical communication, optical communication, etc.

[0241] The image processing unit 11412 performs various types of image processing on the image signal in RAW data form transmitted from the camera 11102.

[0242] The control unit 11413 performs various types of control related to imaging the surgical area, etc., via the endoscope 11100 and displaying the images captured by imaging the surgical area, etc. For example, the control unit 11413 generates control signals for controlling the drive of the camera 11102.

[0243] Furthermore, the control unit 11413 controls the display device 11202 to display captured images of the surgical area, etc., based on image signals that have already been processed by the image processing unit 11412. In this case, the control unit 11413 can identify various objects within the captured images using various image recognition techniques. For example, the control unit 11413 can detect the edge shape and / or color of objects contained in the captured images to identify surgical instruments such as forceps, specific living body parts, bleeding, fog when the energy device 11112 is used, etc. When controlling the display device 11202 to display the captured images, the control unit 11413 can use the recognition results to make the display device 11202 display various types of surgical support information with images of the surgical area in an overlay manner. When surgical support information is displayed in an overlay and presented to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can perform the surgery reliably.

[0244] The transmission cable 11400 that connects the camera 11102 and the CCU 11201 to each other is an electrical signal cable for communication of electrical signals, an optical fiber for communication of optical signals, or a composite cable for both electrical signals and optical communication.

[0245] Here, in the example shown in the attached figure, communication is performed via wired communication using transmission cable 11400, but communication between camera 11102 and CCU 11201 can be performed wirelessly.

[0246] Examples of endoscopic surgical systems to which the technology according to embodiments of the present disclosure is applicable have been described above. The technology according to embodiments of the present disclosure can be applied to, for example, the imaging unit 11402 disposed in the camera 11102 of the endoscope 11100 as described above. By applying the technology according to embodiments of the present disclosure to the imaging unit 11402, an endoscope 11100 with high definition can be provided.

[0247] Although this disclosure has been described above with reference to the implementation scheme, applicable examples and application examples, the technology is not limited to the implementation scheme, etc., and can be modified in many ways.

[0248] In the above embodiments, imaging devices have been exemplified and described; however, for example, it is sufficient for the light detection device of this disclosure to receive incident light and convert the light into electrical charge. The output signal may be a signal of image information or a signal of ranging information. The light detection device (imaging device) is suitable for image sensors, ranging sensors, etc. It should be noted that this disclosure is not limited to back-illuminated image sensors, but is also applicable to front-illuminated image sensors.

[0249] The optical detection device according to this disclosure can also be used as a ranging sensor capable of performing time-of-flight (TOF) distance measurement. The light-receiving element (photoelectric conversion unit) of each pixel can be an avalanche photodiode (APD). The light-receiving element can include, for example, a single-photon avalanche diode (SPAD). The optical detection device (imaging device) can also be used as a sensor capable of detecting events, such as an event-driven sensor (referred to as an event vision sensor (EVS), event-driven sensor (EDS), dynamic vision sensor (DVS), etc.).

[0250] The optical detection device according to an embodiment of this disclosure includes a first layer, a second layer stacked on the first layer, and a photoelectric conversion element. The first layer includes a plurality of first structures having a first refractive index and a first medium, the first medium being disposed within the first layer and having a second refractive index different from the first refractive index. The second layer includes a plurality of second structures having a third refractive index and a second medium, the second medium being disposed within the second layer and having a fourth refractive index different from the third refractive index. The light-receiving side of the photoelectric conversion element is adjacent to the first layer. The plurality of first structures comprise a first material and the plurality of second structures comprise a second material, wherein the first material and the second material are different materials from each other. At least one of the plurality of first structures is in contact with at least one of the plurality of second structures. This enables the realization of an optical detection device that allows for improved characteristics for incident light.

[0251] An optical element according to an embodiment of this disclosure includes a first layer and a first medium. The first layer includes a plurality of first structures having a first refractive index, and the first medium is disposed within the first layer and has a second refractive index. The first refractive index is different from the second refractive index. The optical element also includes a second layer and a second medium. The second layer includes a plurality of second structures having a third refractive index, and the second medium is disposed within the second layer and has a fourth refractive index. The third refractive index is different from the fourth refractive index. The second layer is stacked on top of the first layer. The plurality of first structures comprise a first material, and the plurality of second structures comprise a second material. The first material and the second material are different materials from each other, and at least one of the plurality of first structures is in contact with at least one of the plurality of second structures. This allows for the realization of an optical element with excellent optical properties.

[0252] It should be noted that the effects described herein are merely exemplary and are not limited to the specification, and may include other effects. Furthermore, this disclosure may also have the following configurations.

[0253] (1) A light detection device, comprising:

[0254] The first layer includes a plurality of first structures arranged side by side in a first direction and a first medium disposed around the first structures and having a refractive index different from that of the first structures.

[0255] The second layer comprises a plurality of second structures arranged side-by-side in a first direction and a second medium disposed around the second structures and having a refractive index different from that of the second structures; the second layer is stacked on the first layer.

[0256] A photoelectric conversion element that performs photoelectric conversion on light incident through the second layer and the first layer, wherein

[0257] The first and second structures contain different materials from each other, and

[0258] The first structure is in contact with the second structure.

[0259] (2) The optical detection device according to (1), wherein

[0260] The second structure is configured to be stacked on top of the first structure, and

[0261] The second medium is configured to be stacked on top of the first medium.

[0262] (3) The optical detection device according to (1) or (2), wherein the second medium is made of the same material as the first medium.

[0263] (4) The light detection device according to any one of (1) to (3), wherein the first structure and the second structure have different shapes from each other.

[0264] (5) The light detection device according to any one of (1) to (4), wherein the width of the first structure on the side of the second structure is greater than the width of the first structure on the side opposite to the side of the second structure.

[0265] (6) The light detection device according to any one of (1) to (5), wherein the width of the first structure increases as the distance to the second structure decreases.

[0266] (7) The light detection device according to any one of (1) to (6), wherein the width of the second structure on the side of the first structure is greater than the width of the second structure on the side opposite to the first structure.

[0267] (8) The light detection device according to any one of (1) to (7), wherein the width of the second structure increases as the distance to the first structure decreases.

[0268] (9) The light detection apparatus according to any one of (1) to (8), wherein

[0269] The width of the first structure on the side opposite to the second structure is greater than the width of the first structure on the side opposite to the second structure.

[0270] The width of the second structure on the side of the first structure is greater than the width of the second structure on the side opposite to the first structure.

[0271] (10) The light detection device according to any one of (1) to (9), wherein the first structure has a recess disposed on the side of the second structure.

[0272] (11) The light detection device according to (10), wherein the second structure has a portion disposed in the recess of the first structure.

[0273] (12) The optical detection device according to any one of (1) to (11), wherein the refractive index of the first structure is higher than the refractive index of the second structure.

[0274] (13) The light detection device according to any one of (1) to (12) further includes a blocking film disposed below the first structure between the first structure and the photoelectric conversion element.

[0275] (14) The light detection device according to any one of (1) to (13) further includes an anti-reflective film disposed above the second structure.

[0276] (15) The light detection device according to any one of (1) to (14), wherein the dimensions of the first structure and the second structure are both less than or equal to the wavelength region of visible light.

[0277] (16) An optical element, comprising:

[0278] The first layer includes a plurality of first structures arranged side-by-side in a first direction and a first medium disposed around the first structures and having a refractive index different from that of the first structures; and

[0279] The second layer comprises a plurality of second structures arranged side-by-side in the first direction and a second medium disposed around the second structures and having a refractive index different from that of the second structures. The second layer is stacked on the first layer.

[0280] The first and second structures contain different materials from each other, and

[0281] The first structure is in contact with the second structure.

[0282] (17) The optical element according to (16), wherein

[0283] The second structure is configured to be stacked on top of the first structure, and

[0284] The second medium is configured to be stacked on top of the first medium.

[0285] (18) The optical element according to (16) or (17), wherein the second medium is made of the same material as the first medium.

[0286] (19) An optical element according to any one of (16) to (18), wherein the first structure and the second structure have different shapes from each other.

[0287] (20) An electronic device comprising:

[0288] Optical systems; and

[0289] A light detection device that receives light transmitted through the optical system.

[0290] The optical detection device includes

[0291] The first layer includes a plurality of first structures arranged side by side in a first direction and a first medium disposed around the first structures and having a refractive index different from that of the first structures.

[0292] The second layer comprises a plurality of second structures arranged side-by-side in the first direction and a second medium disposed around the second structures and having a refractive index different from that of the second structures. The second layer is stacked on the first layer.

[0293] A photoelectric conversion element that performs photoelectric conversion on light incident through the second layer and the first layer, wherein

[0294] The first and second structures contain different materials from each other, and

[0295] The first structure is in contact with the second structure.

[0296] Note that this technology can also be configured as follows.

[0297] (1) A light detection device, comprising:

[0298] The first layer includes:

[0299] Multiple first structures with a first refractive index; and

[0300] A first medium, disposed within a first layer and having a second refractive index.

[0301] The first refractive index is different from the second refractive index;

[0302] The second layer includes:

[0303] Multiple second structures with a third refractive index; and

[0304] The second medium, disposed within the second layer, has a fourth refractive index.

[0305] The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and

[0306] Photoelectric conversion element

[0307] The light-receiving side of the photoelectric conversion element is adjacent to the first layer.

[0308] The plurality of first structures comprise a first material and the plurality of second structures comprise a second material.

[0309] The first material and the second material are different materials from each other.

[0310] At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

[0311] (2) The optical detection device according to (1), wherein at least some of the plurality of second structures are configured to be at least partially stacked on the plurality of first structures, at least some of the plurality of second structures are at least partially stacked on the first medium, and at least some portions of the second medium are configured to be at least partially stacked on some portions of the first medium.

[0312] (3) The optical detection device according to (1) or (2), wherein the second medium comprises a fourth material and the first medium comprises a third material, and wherein the third material and the fourth material are the same material.

[0313] (4) The light detection device according to any one of (1) to (3), wherein at least some of the plurality of first structures and at least some of the plurality of second structures have shapes different from each other.

[0314] (5) The light detection device according to any one of (1) to (4), wherein the width of the plurality of first structures up to the top of the second structure is greater than the width of the plurality of first structures on the side opposite to the top of the plurality of second structures.

[0315] (6) The light detection device according to any one of (1) to (5), wherein the plurality of first structures have a tapered structure and the width of the plurality of first structures increases in the direction from the first surface of the first layer to the second surface of the first layer.

[0316] (7) The light detection device according to any one of (1) to (6), wherein the width of the plurality of second structures up to the top of the plurality of first structures is greater than the width of the plurality of second structures on the side opposite to the top of the plurality of first structures.

[0317] (8) The light detection device according to any one of (1) to (7), wherein the plurality of second structures have a tapered structure and the width of the plurality of second structures increases in the direction from the second surface of the second layer to the first surface of the second layer.

[0318] (9) The light detection apparatus according to any one of (1) to (8), wherein

[0319] The width of the plurality of first structures up to the top of the plurality of second structures is greater than the width of the plurality of first structures on the side opposite to the top of the plurality of second structures, and

[0320] The width of the plurality of second structures up to the top of the plurality of first structures is greater than the width of the plurality of second structures on the side opposite to the top of the plurality of first structures.

[0321] (10) The light detection device according to any one of (1) to (9), wherein the plurality of first structures have a recess provided on the end of the surface of the plurality of first structures closest to the second layer.

[0322] (11) The light detection device according to (10), wherein the plurality of second structures have portions disposed in the recesses of the plurality of first structures.

[0323] (12) The optical detection device according to any one of (1) to (11), wherein the first refractive index is higher than the third refractive index.

[0324] (13) The optical detection device according to any one of (1) to (12), wherein the second refractive index is higher than the fourth refractive index.

[0325] (14) The light detection device according to any one of (1) to (13) further includes an anti-reflective film above the second layer.

[0326] (15) The optical detection device according to any one of (1) to (14), wherein the diameter of the plurality of first structures and the plurality of second structures is 80 nm to 800 nm.

[0327] (16) The light detection device according to (1) to (15), wherein at least some of the plurality of first structures and at least some of the plurality of second structures have the same shape.

[0328] (17) An optical element, comprising:

[0329] The first layer includes:

[0330] Multiple first structures with a first refractive index; and

[0331] A first medium, disposed within a first layer and having a second refractive index.

[0332] The first refractive index is different from the second refractive index;

[0333] The second layer includes:

[0334] Multiple second structures with a third refractive index; and

[0335] The second medium, disposed within the second layer, has a fourth refractive index.

[0336] The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and

[0337] The plurality of first structures comprise a first material and the plurality of second structures comprise a second material.

[0338] The first material and the second material are different materials from each other.

[0339] At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

[0340] (18) The optical element according to (16), wherein at least some of the plurality of second structures are configured to be at least partially stacked on at least some of the plurality of first structures, at least some of the plurality of second structures are at least partially stacked on a first medium, and at least some portions of the second medium are configured to be at least partially stacked on at least some portions of the first medium.

[0341] (19) The optical element according to (17) or (18), wherein the second medium comprises a fourth material and the first medium comprises a third material, and wherein the third material and the fourth material are the same material.

[0342] (20) An optical element according to any one of (17) to (19), wherein at least some of the plurality of first structures and at least some of the plurality of second structures have different shapes from each other, and at least some of the plurality of first structures and at least some of the plurality of second structures have the same shape.

[0343] (21) An electronic device, comprising:

[0344] Optical systems; and

[0345] A light detection device that receives light transmitted through the optical system.

[0346] The optical detection device includes:

[0347] The first layer includes:

[0348] Multiple first structures with a first refractive index; and

[0349] A first medium, disposed within a first layer and having a second refractive index.

[0350] The first refractive index is different from the second refractive index;

[0351] The second layer includes:

[0352] Multiple second structures with a third refractive index; and

[0353] The second medium, disposed within the second layer, has a fourth refractive index.

[0354] The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and

[0355] Photoelectric conversion element

[0356] The light-receiving side of the photoelectric conversion element is adjacent to the first layer.

[0357] The plurality of first structures comprise a first material and the plurality of second structures comprise a second material.

[0358] The first material and the second material are different materials from each other.

[0359] At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

[0360] Those skilled in the art will understand that various modifications, combinations, sub-combinations and alterations can be made depending on design requirements and other factors, as long as they are within the scope of the appended claims or their equivalents.

[0361] [List of reference numerals]

[0362] 1 Imaging device

[0363] 10 Semiconductor Layer

[0364] 12 Photoelectric Conversion Unit

[0365] 51 First Structure

[0366] 52 Second Structure

[0367] 60 Light guide section

[0368] 61 First Component

[0369] 62 Second component

[0370] 71 First Floor

[0371] 72 Second Floor

[0372] 80 optical layers

Claims

1. A light detection device, comprising: The first layer includes: Multiple first structures with a first refractive index; and A first medium, disposed within a first layer and having a second refractive index. The first refractive index is different from the second refractive index; The second layer includes: Multiple second structures with a third refractive index; and The second medium, disposed within the second layer, has a fourth refractive index. The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and Photoelectric conversion element The light-receiving side of the photoelectric conversion element is adjacent to the first layer. The plurality of first structures comprise a first material and the plurality of second structures comprise a second material. The first material and the second material are different materials from each other. At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

2. The optical detection device according to claim 1, wherein at least some of the plurality of second structures are configured to be at least partially stacked on the plurality of first structures, at least some of the plurality of second structures are at least partially stacked on the first medium, and at least some portions of the second medium are configured to be at least partially stacked on some portions of the first medium.

3. The optical detection device according to claim 1, wherein the second medium comprises a fourth material and the first medium comprises a third material, and wherein the third material and the fourth material are the same material.

4. The optical detection device according to claim 1, wherein at least some of the plurality of first structures and at least some of the plurality of second structures have shapes different from each other.

5. The optical detection device according to claim 1, wherein the width of the plurality of first structures up to the top of the second structure is greater than the width of the plurality of first structures on the side opposite to the top of the plurality of second structures.

6. The optical detection device according to claim 5, wherein the plurality of first structures have a tapered structure, and the width of the plurality of first structures increases in the direction from the first surface of the first layer to the second surface of the first layer.

7. The optical detection device according to claim 1, wherein the width of the plurality of second structures up to the top of the plurality of first structures is greater than the width of the plurality of second structures on the side opposite to the top of the plurality of first structures.

8. The optical detection device according to claim 7, wherein the plurality of second structures have a tapered structure, and the width of the plurality of second structures increases in the direction from the second surface of the second layer to the first surface of the second layer.

9. The optical detection device according to claim 1, wherein... The width of the plurality of first structures up to the top of the plurality of second structures is greater than the width of the plurality of first structures on the side opposite to the top of the plurality of second structures, and The width of the plurality of second structures up to the top of the plurality of first structures is greater than the width of the plurality of second structures on the side opposite to the top of the plurality of first structures.

10. The light detection device according to claim 1, wherein the plurality of first structures have a recess disposed at the end of the surface of the plurality of first structures closest to the second layer.

11. The light detection device according to claim 10, wherein the plurality of second structures have portions disposed in the recesses of the plurality of first structures.

12. The optical detection device according to claim 1, wherein the first refractive index is higher than the third refractive index.

13. The optical detection device according to claim 1, wherein the second refractive index is higher than the fourth refractive index.

14. The light detection device according to claim 1 further includes an anti-reflective film above the second layer.

15. The photodetector according to claim 1, wherein the diameters of the plurality of first structures and the plurality of second structures are all 80 nm to 800 nm.

16. The optical detection device according to claim 1, wherein at least some of the plurality of first structures and at least some of the plurality of second structures have the same shape.

17. An optical element, comprising: The first layer includes: Multiple first structures with a first refractive index; and A first medium, disposed within a first layer and having a second refractive index. The first refractive index is different from the second refractive index; The second layer includes: Multiple second structures with a third refractive index; and The second medium, disposed within the second layer, has a fourth refractive index. The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and The plurality of first structures comprise a first material and the plurality of second structures comprise a second material. The first material and the second material are different materials from each other. At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

18. The optical element of claim 17, wherein the second medium comprises a fourth material and the first medium comprises a third material, and wherein the third material and the fourth material are the same material.

19. The optical element of claim 17, wherein at least some of the plurality of first structures and at least some of the plurality of second structures have different shapes from each other, and at least some of the plurality of first structures and at least some of the plurality of second structures have the same shape.

20. An electronic device, comprising: Optical system; and A light detection device that receives light transmitted through the optical system. The optical detection device includes: The first layer includes: Multiple first structures with a first refractive index; and A first medium, disposed within a first layer and having a second refractive index. The first refractive index is different from the second refractive index; The second layer includes: Multiple second structures with a third refractive index; and The second medium, disposed within the second layer, has a fourth refractive index. The third refractive index differs from the fourth refractive index, and the second layer is stacked on top of the first layer; and Photoelectric conversion element The light-receiving side of the photoelectric conversion element is adjacent to the first layer. The plurality of first structures comprise a first material and the plurality of second structures comprise a second material. The first material and the second material are different materials from each other. At least one of the plurality of first structures is in contact with at least one of the plurality of second structures.

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