Light detection device and electronic equipment

Abstract

A light detection device according to an embodiment of the present disclosure comprises: a semiconductor layer; first photoelectric conversion regions and second photoelectric conversion regions provided adjacent to each other in the semiconductor layer; and light collection elements provided above the semiconductor layer. The semiconductor layer has first protrusion parts provided between the light collection elements and the first photoelectric conversion regions.

Description

Optical Detection Device and Electronic Device

[0001] The present disclosure relates to an optical detection device and an electronic device.

[0002] An image sensor has been proposed that includes a first curved surface provided on a first photoelectric conversion unit and a second curved surface provided on a second photoelectric conversion unit, and a semiconductor substrate having a minimum thickness at the pixel center and a maximum thickness at the boundary between pixel regions (Patent Document 1).

[0003] US Patent Application Publication No. 2022 / 0190006

[0004] In a device for detecting light, it is desirable to be able to efficiently collect incident light.

[0005] It is desired to provide an optical detection device that can efficiently collect light.

[0006] The optical detection device according to an embodiment of the present disclosure includes a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light collection element provided above the semiconductor layer. The semiconductor layer has a first convex portion provided between the light collection element and the first photoelectric conversion region. The optical detection device according to an embodiment of the present disclosure includes a semiconductor layer, a photoelectric conversion region provided in the semiconductor layer, a light collection element provided above the semiconductor layer, a convex portion provided above the photoelectric conversion region in the semiconductor layer and through which the light transmitted through the light collection element is incident, and a first light shielding member provided between the light collection element and the semiconductor layer and shielding a part of the light transmitted through the light collection element. The electronic device according to an embodiment of the present disclosure includes an optical system and an optical detection device that receives the light transmitted through the optical system. The optical detection device has a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light collection element provided above the semiconductor layer. The semiconductor layer has a first convex portion provided between the light collection element and the first photoelectric conversion region.

[0007] Figure 1 is a block diagram showing an example of the schematic configuration of an imaging device, which is an example of a photodetector according to the first embodiment of this disclosure. Figure 2 is a diagram showing an example of the pixel section of an imaging device according to the first embodiment of this disclosure. Figure 3 is a diagram showing an example of the planar configuration of an imaging device according to the first embodiment of this disclosure. Figure 4 is a diagram showing another example of the planar configuration of an imaging device according to the first embodiment of this disclosure. Figure 5 is a diagram showing an example of the circuit configuration of a pixel in an imaging device according to the first embodiment of this disclosure. Figure 6 is a diagram illustrating an example of the cross-sectional configuration of an imaging device according to the first embodiment of this disclosure. Figure 7 is a diagram illustrating an example of the planar configuration of an imaging device according to the first embodiment of this disclosure. Figure 8 is a diagram illustrating an example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 9 is a diagram illustrating an example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 10 is a diagram illustrating another example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 11 is a diagram illustrating another example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 12 is a diagram illustrating another example of the configuration of an imaging device according to the first embodiment of this disclosure. Figure 13 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 14 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 15 is a diagram illustrating an example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 16 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 17 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 18 is a diagram illustrating another example configuration of an imaging device according to Modification 1 of the present disclosure. Figure 19 is a diagram illustrating an example configuration of an imaging device according to Modification 2 of the present disclosure. Figure 20 is a diagram illustrating an example configuration of an imaging device according to Modification 2 of the present disclosure. Figure 21 is a diagram illustrating an example configuration of an imaging device according to Modification 2 of the present disclosure. Figure 22 is a diagram illustrating another example configuration of an imaging device according to Modification 2 of the present disclosure. Figure 23 is a diagram illustrating an example configuration of an imaging device according to Modification 3 of the present disclosure. Figure 24 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure.Figure 25 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. Figure 26 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. Figure 27 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. Figure 28 is a diagram illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. Figure 29 is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. Figure 30 is a diagram illustrating an example configuration of an imaging device according to Modification 5 of the present disclosure. Figure 31 is a block diagram showing an example configuration of an electronic device having an imaging device. Figure 32 is a block diagram showing an example of a schematic configuration of a vehicle control system. Figure 33 is an explanatory diagram showing an example of the installation position of an external information detection unit and an imaging unit. Figure 34 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. Figure 35 is a block diagram showing an example of the functional configuration of a camera head and a CCU.

[0008] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be in the following order: 1. First Embodiment 2. Second Embodiment 3. Application Example 4. Application Example

[0009] <1. First Embodiment> Figure 1 is a block diagram showing an example of the schematic configuration of an imaging device, which is an example of a photodetector according to the first embodiment of the present disclosure. Figure 2 is a diagram showing an example of the pixel section of an imaging device according to the first embodiment. A photodetector is a device capable of detecting incident light. An imaging device 1, which is an example of a photodetector, has a plurality of pixels P including a photoelectric conversion section (i.e., a photoelectric conversion region), and is configured to generate a signal by photoelectric conversion of incident light.

[0010] The imaging device 1, as an example, receives light transmitted through an optical system (not shown) including an optical lens and generates a signal. The imaging device 1 is constructed using, for example, a semiconductor substrate (such as a Si (silicon) substrate or an SOI (silicon on insulator) substrate) on which each pixel P is provided with a photoelectric conversion unit. The imaging device 1 may have a structure (layered structure) composed of multiple semiconductor layers stacked on top of each other.

[0011] The photoelectric conversion unit of a pixel P is, for example, a photodiode (PD) and is configured to convert light into photoelectric energy. The photoelectric conversion unit of each pixel P can also be called a photoelectric conversion element or a photoelectric conversion region. The imaging device 1 has a region (pixel section 100) where a plurality of pixels P are provided, as shown in the example in Figure 1 or Figure 2. The pixel section 100 can also be called a pixel array in which a plurality of pixels P are arranged. The imaging device 1 has, for example, a pixel section 100 in which a plurality of pixels P are arranged in a matrix in two dimensions as an imaging area.

[0012] The imaging device 1 captures incident light (image light) from the subject to be measured through an optical system including an optical lens. The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can generate pixel signals by photoelectric conversion of the received light (e.g., visible light, infrared light, etc.). The imaging device 1, being a light detection device, is a device capable of receiving light and generating signals, and can also be called a light receiving device.

[0013] The imaging device 1 (light detection device) can be configured as an image sensor, for example. The imaging device 1 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging device 1 can be used in various electronic devices such as digital still cameras, video cameras, and mobile phones.

[0014] As shown in Figure 2, the direction of incidence of light from the subject being measured is defined as the Z-axis direction, the left-right direction perpendicular to the Z-axis direction is defined as the X-axis direction, and the up-down direction perpendicular to both the Z-axis and X-axis directions is defined as the Y-axis direction. In subsequent figures, directions may also be indicated based on the direction of the arrows in Figure 2.

[0015] [Outline Configuration of the Imaging Device] The imaging device 1, as an example, includes a pixel section 100, a pixel control unit 111, a signal processing unit 112, a control unit 113, and a processing unit 114, as shown in Figure 1. The imaging device 1 is also provided with, for example, a plurality of control lines Lread and a plurality of signal lines VSL. The number and arrangement of pixels P provided in the pixel section 100 (i.e., pixel array) can be changed as appropriate.

[0016] The control line Lread is a signal line capable of transmitting signals to control pixels P, and is connected to the pixel control unit 111 and the pixels P of the pixel unit 100. In the example shown in Figure 1, multiple control lines Lread are wired to each pixel row of the pixel unit 100, which is composed of multiple pixels P arranged in the row direction (for example, in the X-axis direction). The control line Lread is configured to transmit control signals for reading signals from the pixels P.

[0017] The multiple control lines Lread for each pixel row of the imaging device 1 include, for example, wiring that transmits signals to control the transfer transistor, wiring that transmits signals to control the selection transistor, wiring that transmits signals to control the reset transistor, etc. The control lines Lread can also be called drive lines (or pixel drive lines) that transmit signals to drive the pixels P.

[0018] The signal line VSL is a signal line capable of transmitting signals from pixels P, and is connected to the pixels P of the pixel unit 100 and the signal processing unit 112. In the pixel unit 100, one or more signal lines VSL are wired for each pixel row, which is composed of multiple pixels P arranged in the column direction (for example, in the Y-axis direction). The signal line VSL is electrically connected to the pixels P and is configured to transmit signals output from the pixels P.

[0019] In the imaging device 1, multiple signal lines VSL may be provided for a single pixel row. For example, the imaging device 1 may have multiple signal lines VSL for each pixel row containing multiple pixels P. The number and arrangement of control lines Lread and signal lines VSL in the imaging device 1 are not limited to the illustrated example and can be changed as appropriate.

[0020] 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 is composed of multiple circuits, such as a buffer, a shift register, and an address decoder. The pixel control unit 111 generates a signal for controlling the pixels P and outputs it 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.

[0021] The pixel control unit 111 generates signals for controlling the pixels P, such as signals to control the transfer transistor of the pixel P, signals to control the selection transistor, and signals to control 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 described as a pixel drive unit (pixel drive circuit) configured to drive each pixel P.

[0022] 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 Digital) conversion circuit, a horizontal selection switch, etc. The load circuit is composed of, for example, a current source capable of supplying current to the amplification transistor of the pixel P. As an example, the load circuit together with the amplification transistor of the pixel P constitutes a source follower circuit.

[0023] Furthermore, the signal processing unit 112 may have an amplification circuit configured to amplify the pixel signal read from the pixel P via the signal line VSL. The load circuit, amplification circuit, and AD conversion circuit, etc., are provided, for example, for each of the multiple signal lines VSL. In the imaging device 1, the load circuit, amplification circuit, and AD conversion circuit, etc., may be provided for each pixel row of the pixel section 100.

[0024] 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 the signal line VSL. The signal processing unit 112 can perform signal processing such as AD conversion and CDS (Correlated Double Sampling) of the pixel P signals. The signals from each pixel P transmitted via each signal line VSL are processed by the signal processing unit 112 and output to the processing unit 114.

[0025] The processing unit 114 is configured to acquire signals from each pixel P and perform signal processing. The processing unit 114 is a processing circuit and consists of, for example, circuits that perform various signal processing on the input pixel signals. The processing unit 114 is configured to include, as an example, an arithmetic circuit, a memory circuit, and the like.

[0026] The processing unit 114 can perform signal processing on the pixel signals input from the signal processing unit 112 and output the processed pixel signals. The processing unit 114 can perform various signal processing such as noise reduction, interpolation, and gradation correction. The processing unit 114 may include a processor and memory.

[0027] The control unit 113 is configured to control each part of the imaging device 1. The control unit 113 receives data such as a clock and operating mode commands from an external source, and can output data such as internal information of the imaging device 1. The control unit 113 is a control circuit and, for example, has a timing generator configured to generate various timing signals.

[0028] The control unit 113 controls the operation of the pixel control unit 111 and the signal processing unit 112, etc., based on various timing signals (pulse signals, clock signals, etc.) generated by the timing generator. The control unit 113 may include circuits such as a PLL (Phase Locked Loop) and a DAC (Digital to Analog Converter). The control unit 113 and the processing unit 114 may be configured as an integrated unit.

[0029] The pixel unit 100, pixel control unit 111, signal processing unit 112, control unit 113, processing unit 114, etc., described above may be provided on a single substrate or on multiple substrates. The imaging device 1 may have a laminated structure formed by stacking multiple substrates.

[0030] The pixel control unit 111, signal processing unit 112, control unit 113, processing unit 114, etc. of the imaging device 1 may be provided, for example, as peripheral circuits in the peripheral area of ​​the pixel unit 100. Note that some or all of the signal processing unit 112, control unit 113, and processing unit 114 may be configured as a single unit.

[0031] Figure 3 is a diagram showing an example of the planar configuration of an imaging device according to the first embodiment. Figure 3 shows an example of the arrangement of pixels P in the pixel section 100 of the imaging device 1. The pixel section 100 of the imaging device 1 is provided with a plurality of pixels P arranged, for example, in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction). Each pixel P has a plurality of photoelectric conversion units 12 (in the example shown in Figure 3, photoelectric conversion units 12a and 12b), a light-collecting element 30, and a filter 40.

[0032] In each pixel P of the imaging device 1, for example, multiple photoelectric conversion units 12 are arranged adjacent to each other. In the example shown in Figure 3, the photoelectric conversion unit 12b is provided next to the photoelectric conversion unit 12a. It can also be said that there are pixels having a photoelectric conversion unit 12a and pixels having a photoelectric conversion unit 12b. Note that a pixel P may be configured to include three or more photoelectric conversion units 12, for example, four photoelectric conversion units 12.

[0033] In the imaging device 1, for example, a light-gathering element 30 and a filter 40 are provided on the side into which light from an optical system such as an imaging lens enters. The light-gathering element 30 is provided, for example, above the photoelectric conversion unit 12a and the photoelectric conversion unit 12b for each pixel P or for each of a group of pixels P. The light-gathering element 30 is configured as an optical element (optical member) that guides light, and can also be called a light guide element (light guide member).

[0034] The light-gathering element 30 (light-gathering member) is composed of, for example, a lens 31. The lens 31 (lens portion) is a lens that focuses light and is an optical component also called an on-chip lens. The lens 31 is composed of, for example, silicon oxide, silicon nitride, or silicon oxynitride. The lens 31 may also be formed using other light-transmitting materials.

[0035] Light from the subject to be measured enters the light-gathering element 30 (i.e., the lens 31) for example, through the optical system. The light-gathering element 30 guides the incident light toward the photoelectric conversion unit 12 of the pixel P. The photoelectric conversion units 12a and 12b convert the light incident through the light-gathering element 30 into photoelectric energy. The photoelectric conversion units 12a and 12b can absorb the incident light and generate an electric charge.

[0036] The filter 40 is configured, for example, to selectively transmit light in a specific wavelength band from the incident light. The filter 40 is provided above the photoelectric conversion unit 12a and the photoelectric conversion unit 12b for each pixel P or for each set of pixels P. The photoelectric conversion units 12a and 12b convert the light incident via the light-collecting element 30 and the filter 40 into photoelectric energy. The filter 40 is, for example, an RGB color filter.

[0037] The pixel section 100 of the imaging device 1 includes, for example, a pixel Pr (R pixel) that receives and converts light in the red (R) wavelength range into photoelectric light, a pixel Pg (G pixel) that receives and converts light in the green (G) wavelength range into photoelectric light, and a pixel Pb (B pixel) that receives and converts light in the blue (B) wavelength range into photoelectric light. For example, pixel Pr has a filter 40 that transmits red (R) light, pixel Pg has a filter 40 that transmits green (G) light, and pixel Pb has a filter 40 that transmits blue (B) light.

[0038] In the pixel section 100, multiple pixels Pr, multiple pixels Pg, and multiple pixels Pb are arranged in a repeating pattern. For example, pixels Pr, pixels Pg, and pixels Pb are arranged according to a Bayer array. Pixels Pr, pixels Pg, and pixels Pb generate pixel signals for the R component, G component, and B component, respectively. The imaging device 1 can obtain RGB pixel signals. Note that the arrangement of pixels P is not limited to the example described above and can be set arbitrarily.

[0039] Figure 4 shows another example of the planar configuration of the imaging device according to the first embodiment. The R pixels, G pixels, and B pixels may each be arranged in 2x2 pixel units. As shown in the example in Figure 4, in the pixel section 100, four adjacent pixels Pr, four adjacent pixels Pg, and four adjacent pixels Pb are repeatedly arranged. It can also be said that the pixels Pr, Pg, and Pb are each arranged periodically in a 2x2 grid.

[0040] Note that the filter 40 provided for the pixel P of the pixel unit 100 is not limited to a color filter of the primary color system (RGB), and may be, for example, a color filter of a complementary color system such as Cy (cyan), Mg (magenta), Ye (yellow), etc. A filter corresponding to W (white), that is, a filter that transmits light in the entire wavelength range of incident light, may be arranged. The filter 40 may be a filter that transmits infrared light.

[0041] Note that in the imaging device 1, the filter 40 may be omitted as necessary. For example, depending on the characteristics of the condensing element 30, the filter 40 may not be provided for some or all of the pixels P of the imaging device 1. Also, for example, in the pixel P that receives white (W) light and performs photoelectric conversion, the filter 40 may not be provided.

[0042] In the imaging device 1, as described above, for example, one condensing element 30 (that is, the lens 31) is provided for two photoelectric conversion units 12 (the photoelectric conversion unit 12a and the photoelectric conversion unit 12b). In the imaging device 1, the photoelectric conversion unit 12a and the photoelectric conversion unit 12b receive light that has passed through different regions of the optical system such as an imaging lens, and pupil division is performed.

[0043] By using the signal based on the charge photoelectrically converted by the photoelectric conversion unit 12a and the signal based on the charge photoelectrically converted by the photoelectric conversion unit 12b, phase difference data (phase difference information) can be obtained. For example, the processing unit 114 of the imaging device 1 is configured to acquire phase difference data based on the pixel signal output from the phase difference pixel. By using the phase difference data, phase difference AF (Auto Focus) can be performed.

[0044] The pixel P (pixel Pr, pixel Pg, or pixel Pb, etc.) of the imaging device 1 is a pixel that can be used for phase difference detection, and can be said to be a phase difference pixel (or a phase difference detection pixel). Pixels P configured as phase difference pixels may be repeatedly provided over the entire imaging surface, that is, the entire pixel unit 100. The pixels P configured as phase difference pixels may be discretely arranged in the pixel unit 100.

[0045] In addition, the imaging device 1 can perform signal processing on the pixel signals of each pixel P to generate image data. For example, the processing unit 114 is configured to be able to generate image data indicating a subject image based on the pixel signals output from each pixel P. The processing unit 114 may generate image data using pixel signals based on the charges obtained by adding the charges photoelectrically converted by the photoelectric conversion unit 12a and the photoelectric conversion unit 12b.

[0046] [Pixel Configuration] FIG. 5 is a diagram showing an example of the circuit configuration of a pixel of the imaging device according to the first embodiment. The pixel P includes a plurality of photoelectric conversion units 12 (in FIG. 5, photoelectric conversion unit 12a and photoelectric conversion unit 12b), a plurality of transistors TR (in FIG. 5, transistor TR1 and transistor TR2), a floating diffusion FD, and a readout circuit 20.

[0047] The photoelectric conversion unit 12 is configured to receive light and generate a signal. The photoelectric conversion unit 12 (that is, the photoelectric conversion region) is configured to be able to generate charges by photoelectric conversion. In the example shown in FIG. 5, the photoelectric conversion unit 12a and the photoelectric conversion unit 12b are each a photodiode (PD).

[0048] The photoelectric conversion unit 12a and the photoelectric conversion unit 12b each convert the incident light into charges. Each of the photoelectric conversion unit 12a and the photoelectric conversion unit 12b can perform photoelectric conversion to generate charges corresponding to the amount of received light. Note that the photoelectric conversion units 12a and 12b are photoelectric conversion elements and can also be said to be light receiving elements.

[0049] The transistor TR (in FIG. 5, transistor TR1 and transistor TR2) is configured to be able to transfer the charges photoelectrically converted by the photoelectric conversion unit 12 to the floating diffusion FD. The transistor TR electrically connects or disconnects the photoelectric conversion unit 12 and the floating diffusion FD. The transistor TR is a transfer transistor.

[0050] In the example shown in Figure 5, transistors TR1 and TR2 are controlled by different signals. Transistor TR1 is controlled by signal STR1 and electrically connects or disconnects the photoelectric conversion unit 12a and the floating diffusion FD. Transistor TR1 can transfer the charge that has been photoelectrically converted and stored in the photoelectric conversion unit 12a to the floating diffusion FD.

[0051] Transistor TR2 is controlled by signal STR2 to electrically connect or disconnect the photoelectric conversion unit 12b and the floating diffusion FD. Transistor TR2 can transfer the charge stored by photoelectric conversion in the photoelectric conversion unit 12b to the floating diffusion FD.

[0052] The floating diffusion FD is a storage unit and is configured to store the transferred charge. The floating diffusion FD can store the charge photoelectrically converted by the photoelectric conversion unit 12. The floating diffusion FD stores the transferred charge and converts it into a voltage corresponding to the capacitance of the floating diffusion FD. The floating diffusion FD can also be described as a storage unit capable of holding charge.

[0053] The readout circuit 20 is configured to output a signal based on the photoelectrically converted charge, for example. The readout circuit 20 is configured to output a pixel signal based on the charge generated by the photoelectric conversion unit 12a and a pixel signal based on the charge generated by the photoelectric conversion unit 12b. Furthermore, the readout circuit 20 is configured to output a pixel signal corresponding to the charge obtained by adding the charge photoelectrically converted by the photoelectric conversion unit 12a and the charge photoelectrically converted by the photoelectric conversion unit 12b.

[0054] The readout circuit 20, as an example, includes a transistor AMP, a transistor SEL, and a transistor RST, as shown in Figure 5. The readout circuit 20 can read out pixel signals based on the charge photoelectrically converted in the photoelectric conversion unit 12 (photoelectric conversion region). The readout circuit 20 may also include a floating diffusion FD.

[0055] The transistor AMP is configured to generate and output a signal based on the charge stored in the floating diffusion FD. The transistor AMP is an amplifying transistor. The transistor AMP can generate and output a signal based on the charge converted by the photoelectric conversion unit 12.

[0056] The gate of the transistor AMP is electrically connected to the floating diffusion diode (FD), and the voltage converted by the floating diffusion diode is input to it. The drain of the transistor AMP is connected to a power line that supplies, for example, the power supply voltage (power supply voltage VDD in the example shown in Figure 5).

[0057] The source of the transistor AMP is connected to the signal line VSL, for example, via the transistor SEL. The transistor AMP is configured to generate a signal based on the charge stored in the floating diffusion FD, i.e., a signal based on the voltage of the floating diffusion FD, and output it to the signal line VSL.

[0058] The transistor SEL is configured to control the output of the pixel signal. The transistor SEL is electrically connected in series with the transistor AMP, for example, as shown in Figure 5. The transistor SEL is controlled by the signal SSEL and is configured to output the signal from the transistor AMP to the signal line VSL. The transistor SEL is a selection transistor. The transistor SEL can control the timing of the pixel signal output.

[0059] The transistor SEL is configured to output a signal based on the charge converted by the photoelectric conversion unit 12. The transistor SEL can output the pixel signal of pixel P to the signal line VSL. The transistor SEL may also be electrically connected in series between the power line to which the power supply voltage (power supply voltage VDD in Figure 5) is supplied and the transistor AMP. Furthermore, the transistor SEL may be omitted if necessary.

[0060] The transistor RST is configured to reset the voltage of the floating diffusion FD. In the example shown in Figure 5, the transistor RST is electrically connected to a power line to which the power supply voltage VDD is supplied and is configured to perform a reset of the charge of pixel P. The transistor RST is a reset transistor.

[0061] The transistor RST is controlled by the signal SRST and can reset the charge accumulated in the floating diffusion FD and reset the voltage of the floating diffusion FD. Transistor RST electrically connects, for example, the power line to the floating diffusion FD and discharges the charge accumulated in the floating diffusion FD. Transistor RST can also reset the charge accumulated in the photoelectric conversion unit 12 via transistor TR.

[0062] The readout circuit 20 may be configured to allow changing the conversion gain (i.e., conversion efficiency) when converting charge to voltage. The readout circuit 20 may have, for example, a transistor (switching transistor) used to set the conversion gain. The switching transistor is electrically connected, for example, between the floating diffusion FD and the transistor RST.

[0063] In the readout circuit 20, when the switching transistor is turned ON, the capacitance added to the floating diffusion FD of the pixel P increases, and the conversion gain (conversion efficiency) when converting charge to voltage is switched. The switching transistor can change the conversion gain by switching the capacitance connected to the gate of transistor AMP. The switching transistor may be electrically connected in series with transistor RST or electrically connected in parallel with transistor RST.

[0064] The aforementioned transistors TR (transfer transistor), AMP (amplifier transistor), SEL (selection transistor), RST (reset transistor), and switching transistor are, for example, MOS transistors (MOSFETs) having gate, source, and drain terminals.

[0065] In the example shown in Figure 5, transistors TR, AMP, SEL, and RST are each composed of NMOS transistors. Note that the transistor for pixel P may be composed of a PMOS transistor.

[0066] The pixel control unit 111 (see Figure 1) of the imaging device 1 supplies control signals to the gates of transistors TR (transistors TR1, TR2), transistor SEL, transistor RST, switching transistors, etc. of each pixel P via the control line Lread described above, and sets the transistors to an ON state (conducting state) or an OFF state (non-conducting state).

[0067] The multiple control lines Lread for each pixel row of the imaging device 1 include, as an example, wiring that transmits signals STR (signals STR1, STR2) that control transistor TR, wiring that transmits signals SSEL that control transistor SEL, wiring that transmits signals SRST that control transistor RST, wiring that transmits signals that control switching transistors, and so on.

[0068] Transistors TR, SEL, RST, and switching transistors are controlled on and off by the pixel control unit 111. The pixel control unit 111 controls the readout circuit 20 for each pixel P, causing each pixel P to output a pixel signal to the signal line VSL. The pixel control unit 111 can control the reading of the pixel signal from each pixel P to the signal line VSL.

[0069] The imaging device 1 may have a configuration in which multiple pixels P share one readout circuit 20. In the imaging device 1, the readout circuit 20 can be provided for multiple pixels P. For example, in the imaging device 1, a readout circuit 20 is provided for each of the multiple pixels P, and the multiple pixels P share one readout circuit 20. As an example, a 2x2 pixel array, composed of four adjacent pixels P, may share one readout circuit 20.

[0070] [Configuration of the Imaging Device] Figure 6 is a diagram illustrating an example of the cross-sectional configuration of the imaging device according to the first embodiment. Figure 7 is a diagram illustrating an example of the planar configuration of the imaging device according to the first embodiment. Figure 6 shows, for example, an example of the cross-sectional configuration of the imaging device in the direction of line A-A' shown in Figure 7.

[0071] The imaging device 1, as shown in the example in Figure 6, includes a light-gathering element 30, a filter 40, an insulating layer 50, a semiconductor layer 10, and a wiring layer 90. The imaging device 1 has a configuration in which the light-gathering element 30, filter 40, insulating layer 50, semiconductor layer 10, and wiring layer 90 are stacked in the Z-axis direction. The light-gathering element 30, filter 40, insulating layer 50, semiconductor layer 10, and wiring layer 90 are provided from the side where light is incident.

[0072] The semiconductor layer 10 is composed of a semiconductor substrate (e.g., a Si substrate, an SOI substrate, etc.). The semiconductor layer 10 may be a SiGe (silicon germanium) substrate, a SiC (silicon carbide) substrate, etc., or may be formed using other semiconductor materials. The semiconductor layer 10 may be composed of a compound semiconductor material of the III-V group, etc.

[0073] As shown in Figure 6, the semiconductor layer 10 has opposing surfaces 11S1 and 11S2. Surface 11S2 is the surface opposite to surface 11S1. For example, surface 11S1 of the semiconductor layer 10 is the light-receiving surface (i.e., the light incident surface). Surface 11S2 of the semiconductor layer 10 is the element-forming surface on which elements such as transistors and capacitive elements are formed. Surface 11S2 of the semiconductor layer 10 may be provided with a gate electrode, a gate insulating film (e.g., a gate oxide film), etc.

[0074] An insulating film 25 and an insulating layer 50 are provided on the surface 11S1 side of the semiconductor layer 10. The light-gathering element 30 (i.e., lens 31), filter 40, and insulating layer 50 are stacked on the semiconductor layer 10 in the thickness direction (i.e., the Z-axis direction) perpendicular to the surface 11S1 of the semiconductor layer 10. The filter 40 is provided, for example, between the light-gathering element 30 and the insulating layer 50.

[0075] A wiring layer 90 is provided on the surface 11S2 side of the semiconductor layer 10. In the example shown in Figure 6, the light-gathering element 30 and filter 40 are provided on the side into which light from the optical system is incident, and the wiring layer 90 is provided on the side opposite to the side into which light is incident. The imaging device 1 is configured as a so-called back-illuminated imaging device.

[0076] In the semiconductor layer 10, a plurality of photoelectric conversion units 12 (photoelectric conversion regions) are provided along the surfaces 11S1 and 11S2 of the semiconductor layer 10. For example, a plurality of photoelectric conversion units 12a and a plurality of photoelectric conversion units 12b are embedded in the semiconductor layer 10. The photoelectric conversion units 12a and 12b are provided between the surfaces 11S1 and 11S2 of the semiconductor layer 10.

[0077] The photoelectric conversion units 12a and 12b are arranged in the semiconductor layer 10 so as to be aligned in the X-axis direction (or Y-axis direction). The photoelectric conversion units 12a and 12b convert the light incident via the light-collecting element 30, filter 40, and insulating layer 50 into photoelectric energy. The photoelectric conversion units 12a and 12b are photoelectric conversion regions, and can also be called photoelectric conversion layers.

[0078] The wiring layer 90 is provided laminated on the semiconductor layer 10. The wiring layer 90 includes, for example, a conductive film and an insulating film, and has a plurality of wirings and vias. The wiring layer 90 has a configuration in which a plurality of wirings are laminated with an insulating film acting as an interlayer insulating film (interlayer insulating layer). The wiring layer 90 is configured as, for example, a multilayer wiring layer and includes two or more layers, or three or more layers of wiring.

[0079] The wiring in the wiring layer 90 is formed using a metallic material such as aluminum (Al), copper (Cu), or tungsten (W). The wiring in the wiring layer 90 may also be made of polysilicon (Poly-Si) or other conductive materials. The interlayer insulating film is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), or silicon oxynitride (SiON). The interlayer insulating film may also be made of other insulating materials.

[0080] For example, the above-described readout circuit 20 (see Figure 5) is provided in the semiconductor layer 10 and the wiring layer 90 for each pixel P or for each of a plurality of pixels P (i.e., for each predetermined number of pixels P). In addition, the above-described pixel control unit 111, signal processing unit 112, control unit 113, processing unit 114 (see Figure 1), etc., may be provided in the semiconductor layer 10 and the wiring layer 90, or on a substrate separate from the semiconductor layer 10.

[0081] The insulating layer 50 is provided between the semiconductor layer 10 and the layer on which the filter 40 is provided. The insulating layer 50 is provided so as to be laminated on the semiconductor layer 10 and is located on the surface 11S1 of the semiconductor layer 10. The insulating layer 50 is, for example, a resin layer and is formed using a resin material. The insulating layer 50 may also be composed of an insulating film such as an oxide film, a nitride film, or an oxynitride film.

[0082] The insulating layer 50 may be made of an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide, or it may be made of other materials. The insulating layer 50 may be made of a low refractive index material such as silicon oxide. The insulating layer 50 may be made of a transparent material that transmits light in the wavelength range to be measured. The insulating layer 50 can also be called a planarization layer.

[0083] As shown in Figure 6, the imaging device 1 has a pixel isolation region 61 and an isolation region 62. The pixel isolation region 61 is an isolation region (isolation part) provided around a pixel P. The pixel isolation region 61 is provided in the semiconductor layer 10 between a plurality of adjacent pixels P and separates the pixels P. The pixel isolation region 61 is constructed, for example, using a trench (groove).

[0084] At least a portion of the pixel isolation region 61 is formed at the boundary between adjacent pixels P (or photoelectric conversion units 12). The pixel isolation region 61 may be arranged in a grid pattern so as to surround the photoelectric conversion units 12a and 12b in a plan view (i.e., when viewed in the XY plane). The pixel isolation region 61 is formed, for example, so as to penetrate the semiconductor layer 10.

[0085] An insulating film, such as a silicon oxide film, silicon nitride film, or aluminum oxide film, is provided in the trench of the pixel isolation region 61. Polysilicon, a metallic material, or other insulating material may be embedded in the trench of the pixel isolation region 61. It can also be said that the pixel P has a structure partitioned by the pixel isolation region 61. The pixel isolation region 61 can also be called a pixel isolation section or a pixel isolation wall.

[0086] The pixel isolation region 61 may be composed of a semiconductor region (p-type or n-type semiconductor region) formed by ion implantation. The pixel isolation region 61 may also be formed using other insulating materials having a low refractive index. A void (cavity) may be provided within the pixel isolation region 61.

[0087] The separation region 62 is provided between a plurality of adjacent photoelectric conversion units 12, as shown in the example in Figure 6. At least a portion of the separation region 62 is provided, for example, at the boundary between a plurality of adjacent photoelectric conversion units 12. The separation region 62 is formed, for example, between photoelectric conversion unit 12a and photoelectric conversion unit 12b, separating the photoelectric conversion unit 12a and photoelectric conversion unit 12b.

[0088] The isolation region 62 is constructed, for example, using a trench. As an example, the isolation region 62 extends from the surface 11S1 side of the semiconductor layer 10 to the space between surfaces 11S1 and 11S2 of the semiconductor layer 10. The isolation region 62 may also be provided so as to penetrate the semiconductor layer 10.

[0089] An insulating film (insulator), such as an oxide film (e.g., silicon oxide film) or a nitride film (e.g., silicon nitride film), may be provided in the trench of the isolation region 62. Polysilicon, metallic materials, other insulating materials, etc., may be embedded in the isolation region 62. The isolation region 62 may also be composed of semiconductor regions formed by ion implantation. The isolation region 62 may have voids (cavities).

[0090] Furthermore, the imaging device 1 is provided with a light-shielding member 71 and an insulating film 25. The light-shielding member 71 is a light-shielding portion (light-shielding film) composed of a light-blocking material, and is provided on the surface 11S1 side of the semiconductor layer 10. In the example shown in Figure 6, the light-shielding member 71 is provided on the insulating layer 50. As an example, the light-shielding member 71 is made of a light-blocking metal material. The light-shielding member 71 may also be made of a light-absorbing material.

[0091] The light-shielding member 71 is provided, for example, around the pixel P in the insulating layer 50. At least a portion of the light-shielding member 71 may be located at the boundary between a plurality of adjacent pixels P. It can also be said that the light-shielding member 71 is positioned by replacing a portion of the insulating layer 50. The insulating layer 50 is formed to cover the light-shielding member 71.

[0092] The light-shielding member 71 is made of a light-shielding material, such as tungsten, aluminum, copper, titanium, or titanium nitride. The light-shielding member 71 may also be formed from other materials. The light-shielding member 71 may also be made of a laminated film formed by stacking multiple films. In the imaging device 1, the provision of the light-shielding member 71 helps to suppress the leakage of unwanted light to surrounding pixels P.

[0093] The insulating film 25 is made of an insulating material and is provided on the surface 11S1 side of the semiconductor layer 10. The insulating film 25 is provided, for example, between the semiconductor layer 10 and the insulating layer 50. The insulating film 25 is an insulating film (insulator) such as an oxide film, a nitride film, or an oxynitride film. A part of the insulating film 25 may be provided in the isolation region 62. For example, the insulating film 25 can be integrally formed with the insulating film in the trench of the isolation region 62.

[0094] The insulating film 25 is, for example, made of silicon oxide (SiO). The insulating film 25 may also be made of insulating materials such as silicon nitride (SiN) or aluminum oxide (AlO), or other materials. A portion of the insulating film 25 may be provided within the trench of the pixel separation region 61.

[0095] The imaging device 1 has a convex structural portion provided on the semiconductor layer 10 and is configured to guide incident light toward the photoelectric conversion unit 12. The semiconductor layer 10 has one or more convex portions 15 (convex structures). The convex portions 15 are provided, for example, on the surface 11S1 side of the semiconductor layer 10. The convex portions 15 are formed on the semiconductor layer 10 and may be located between the light-gathering element 30 and the photoelectric conversion unit 12.

[0096] Light from the subject to be measured enters the protrusions 15 of the semiconductor layer 10 via the light-collecting element 30 and the filter 40, etc. The imaging device 1 may be configured to guide the incident light using the protrusions 15. The semiconductor layer 10 is configured to have a plurality of protrusions 15 (protrusions 15a and 15b in the example shown in Figures 6 and 7), for example, corresponding to the number of photoelectric conversion units 12.

[0097] In the imaging device 1, as an example, one protrusion 15 is provided for one photoelectric conversion unit 12. The protrusion 15 is part of the semiconductor layer 10 and can be provided integrally with the semiconductor layer 10. The protrusion 15 is, for example, an n-type semiconductor region or a p-type semiconductor region. The protrusion 15 of the semiconductor layer 10 can be formed, for example, using lithography and etching.

[0098] In the imaging device 1, for example, a protrusion 15a and a protrusion 15b are provided on the surface 11S1 side of the semiconductor layer 10 for each pixel P. In the example shown in Figures 6 and 7, the protrusion 15a of the semiconductor layer 10 is provided between the light-gathering element 30 and the photoelectric conversion unit 12a. The protrusion 15a is provided relative to the photoelectric conversion unit 12a and is located above the photoelectric conversion unit 12a.

[0099] Furthermore, the protrusion 15b of the semiconductor layer 10 is provided between the light-gathering element 30 and the photoelectric conversion unit 12b. The protrusion 15b is provided relative to the photoelectric conversion unit 12b and is located above the photoelectric conversion unit 12b. The protrusions 15a and 15b each have a spherical shape, for example, as shown in the examples in Figures 6 and 7. Each of the protrusions 15a and 15b may be provided to have a convex lens shape.

[0100] In the example shown in Figure 6, a portion of the separation region 62 is provided between the protrusions 15a and 15b. The protrusions 15a and 15b are arranged, for example, adjacent to each other with a portion of the separation region 62 in between. An insulating film 25 is provided around the protrusions 15a and 15b. The insulating film 25 is formed, for example, to cover the protrusions 15a and 15b.

[0101] The protrusions 15 (protrusions 15a, protrusions 15b) of the semiconductor layer 10 have a convex shape toward, for example, the light-gathering element 30 (i.e., the lens 31). The protrusions 15 are structural parts (convex structural parts) that protrude from the semiconductor layer 10 toward the light-gathering element 30 (lens 31), and can also be called protruding parts.

[0102] The protrusion 15a of the semiconductor layer 10 is, for example, a protrusion extending from the photoelectric conversion section 12a toward the insulating layer 50, and is formed to protrude from the photoelectric conversion section 12a toward the light-gathering element 30. The protrusion 15b of the semiconductor layer 10 is a protrusion extending from the photoelectric conversion section 12b toward the insulating layer 50, and is formed to protrude from the photoelectric conversion section 12b toward the light-gathering element 30.

[0103] The protrusions 15 of the semiconductor layer 10 have a refractive index different from that of the surrounding material (e.g., the insulating film 25). The protrusions 15a and 15b of the semiconductor layer 10 have a refractive index higher than that of the insulating film 25, which is the material surrounding the protrusions 15a and 15b.

[0104] The insulating film 25 has a refractive index lower than, for example, the refractive index of the protrusion 15 of the semiconductor layer 10. The insulating film 25 is made of a material (for example, silicon oxide, silicon oxynitride, etc.) that has a refractive index lower than the refractive index of the protrusion 15a (or protrusion 15b) of the semiconductor layer 10, and has a refractive index lower than the refractive index of the protrusion 15a (or protrusion 15b) of the semiconductor layer 10.

[0105] The imaging device 1 changes the direction of incident light propagation based on the refractive index difference between the protrusion 15 of the semiconductor layer 10 and the surrounding material (medium). In Figure 6, light incident from above on the photoelectric conversion unit 12a side via the light-gathering element 30 and filter 40 travels towards the photoelectric conversion unit 12a according to the refractive index difference between the protrusion 15a and the insulating film 25. By providing the protrusion 15a, the direction of light propagation is adjusted, and light can be focused towards the photoelectric conversion unit 12a.

[0106] Furthermore, in Figure 6, light incident on the photoelectric conversion unit 12b side from above via the light-gathering element 30 and filter 40 travels toward the photoelectric conversion unit 12b according to the refractive index difference between the convex portion 15b and the insulating film 25. In the imaging device 1, the convex portion 15b is provided, which adjusts the direction of light propagation and allows light to be focused toward the photoelectric conversion unit 12b.

[0107] In the imaging device 1, the protrusions 15 of the semiconductor layer 10 are provided such that they have the maximum thickness in the region between adjacent photoelectric conversion units 12 and between adjacent pixels P, as shown in the example in Figure 6. The thickness of the semiconductor layer 10 in a certain pixel P is, for example, greatest between the boundary between adjacent photoelectric conversion units 12 and the boundary between that pixel P and the adjacent pixel P.

[0108] The protrusion 15a of the semiconductor layer 10 has its maximum thickness (i.e., height (length) in the Z-axis direction) between the boundary B1 between the photoelectric conversion unit 12a and the photoelectric conversion unit 12b and the boundary B2 between the pixel Pg and the pixel Pr, as shown in the example in Figure 8. Similarly, the protrusion 15b also has its maximum thickness between the boundary B1 between the photoelectric conversion unit 12a and the photoelectric conversion unit 12b and the boundary B2 between the pixel Pg and the pixel Pr.

[0109] In the example shown in Figure 8, the thickness of the semiconductor layer 10 in pixel Pg is maximum between the boundary B1 between photoelectric conversion units 12a and 12b and between the boundary B2 between pixel Pg and pixel Pr. Similarly, the thickness of the semiconductor layer 10 in pixel Pr is maximum between the boundary B1 between photoelectric conversion units 12a and 12b and between the boundary B2 between pixel Pr and pixel Pg.

[0110] The photoelectric conversion unit 12a of pixel P receives incident light via the light-collecting element 30, filter 40, and protrusion 15a, performs photoelectric conversion, and can generate an electric charge corresponding to the amount of light received. The photoelectric conversion unit 12b receives incident light via the light-collecting element 30, filter 40, and protrusion 15b, performs photoelectric conversion, and can generate an electric charge corresponding to the amount of light received.

[0111] In the imaging device 1 according to this embodiment, the protrusion 15 is provided such that it has the maximum thickness in the region between adjacent photoelectric conversion units 12 and between adjacent pixels P, as described above. Therefore, as schematically shown by the dashed arrow in Figure 9, light can be appropriately guided to the photoelectric conversion units 12a and 12b.

[0112] In the imaging device 1, the convex portion 15a allows light to be focused onto the photoelectric conversion unit 12a. Furthermore, the convex portion 15b allows light to be focused onto the photoelectric conversion unit 12b. Light from the optical system is appropriately guided by the convex portions 15a and 15b and incident onto the photoelectric conversion units 12a and 12b. This makes it possible to reduce light scattering at the boundaries of pixels P (or photoelectric conversion unit 12).

[0113] In the imaging device 1, the convex portions 15a and 15b are provided, allowing light to be efficiently guided to the photoelectric conversion unit 12a and the photoelectric conversion unit 12b. As a result, the photoelectric conversion unit 12a and the photoelectric conversion unit 12b can accurately receive light that has passed through different regions of the optical system, and pupil division can be performed appropriately. This makes it possible to suppress a decrease in the accuracy of phase difference detection using pixel signals.

[0114] In this embodiment, the light separation performance when the image is out of focus (i.e., the separation performance between the pixel signal based on the charge converted by the photoelectric conversion unit 12a and the pixel signal based on the charge converted by the photoelectric conversion unit 12b) can be improved. This suppresses a decrease in the accuracy of phase difference detection and prevents a decrease in AF performance. In particular, even in the case of fine pixels, the convex portions 15a and 15b appropriately focus the incident light, thereby improving AF performance.

[0115] Furthermore, the imaging device 1 is provided with protrusions 15a and 15b, which suppresses the leakage of unwanted light to surrounding pixels P. This suppresses the leakage of light to surrounding pixels P, thereby suppressing color mixing. It also suppresses the introduction of noise into the pixel signal. Finally, it suppresses the degradation of image quality in images generated using the pixel signal.

[0116] Figure 10 is a diagram illustrating another example of the configuration of the imaging device according to the first embodiment. The configuration of the imaging device 1 is not limited to the example described above and can be modified as appropriate. For example, the imaging device 1 may have a reflection suppression film 23 (anti-reflective film) on the surface 11S1 side of the semiconductor layer 10, as shown in the example in Figure 10.

[0117] The reflection suppression film 23 is, for example, made of a metal oxide such as hafnium oxide or tantalum oxide. The reflection suppression film 23 (anti-reflective film) is provided on the surface 11S1 side of the semiconductor layer 10 to reduce (suppress) reflection. The reflection suppression film 23 may be made of an insulating material such as silicon nitride, silicon oxide, or aluminum oxide, or it may be made of other materials.

[0118] Furthermore, the imaging device 1 may have a fixed charge film on the surface 11S1 side of the semiconductor layer 10. The fixed charge film is provided, for example, laminated with the reflection suppression film 23. The fixed charge film and the reflection suppression film 23 are, for example, composed of a metal compound (metal oxide, metal nitride, etc.) and can also be called a metal compound layer. The fixed charge film is a film having a fixed charge and can be formed using a high dielectric material.

[0119] The fixed charge film is composed of a metal oxide such as aluminum oxide or hafnium oxide, for example. The fixed charge film is, for example, a film having a negative fixed charge. At least one part of the fixed charge film and the reflection suppression film 23 may be provided in the semiconductor layer 10 along the side wall (side surface) of the isolation region 62 (or pixel isolation region 61).

[0120] In the imaging device 1, the presence of a fixed charge film suppresses the generation of dark current at the interface of the semiconductor layer 10. The fixed charge film may be composed of other metal oxide films, or it may be composed of a metal nitride film or a metal oxynitride film. In the imaging device 1, the fixed charge film may be a film having a positive fixed charge.

[0121] Figures 11 and 12 are diagrams illustrating another configuration example of the imaging device according to the first embodiment. In the imaging device 1, for example, the insulating layer 50 may be omitted, as shown in the example in Figure 11. In the example shown in Figure 11, the imaging device 1 has a configuration without an insulating layer 50. For example, the filter 40 may be provided on the insulating film 25 without an insulating layer 50 in between.

[0122] In the imaging device 1, an insulating film 25 may be provided along the surface 11S1 of the semiconductor layer 10, as shown in the example in Figure 12. The insulating film 25 does not have to have a flat shape. In the example shown in Figure 12, the insulating film 25 is provided along the protrusions 15a and 15b of the semiconductor layer 10.

[0123] [Function and Effects] The photodetector according to this embodiment comprises a semiconductor layer (semiconductor layer 10), a first photoelectric conversion region and a second photoelectric conversion region (for example, photoelectric conversion section 12a, photoelectric conversion section 12b) provided adjacent to each other in the semiconductor layer, and a light-gathering element (light-gathering element 30) provided above the semiconductor layer. The semiconductor layer has a first protrusion (for example, protrusion 15a) provided between the light-gathering element and the first photoelectric conversion region.

[0124] In the light detection device (imaging device 1) according to this embodiment, the semiconductor layer 10 has a protrusion 15 provided between the light-collecting element 30 and the photoelectric conversion unit 12. This allows the incident light to be efficiently focused onto the photoelectric conversion unit 12. This makes it possible to realize a light detection device that can efficiently focus light.

[0125] Next, modified examples of the present disclosure will be described. In the following, components similar to those in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0126] (Modification 1) Figures 13 and 14 are diagrams illustrating an example of the configuration of an imaging device according to Modification 1 of the present disclosure. Figure 13 shows an example of the cross-sectional configuration of the imaging device, and Figure 14 shows an example of the planar configuration of the imaging device. Figure 13 corresponds, for example, to an example of the cross-sectional configuration of the imaging device in the direction of line A-A' shown in Figure 14.

[0127] The shape of the protrusion 15 is not limited to the examples described above and can be changed as appropriate. For example, as shown in the examples in Figures 13 and 14, the protrusions 15a and 15b of the semiconductor layer 10 may be configured to have a cylindrical shape. The protrusions 15a and 15b have a cylindrical lens shape. In this modified example, the same effects as in the above-described embodiment can be obtained.

[0128] The insulating film 25 may be formed along the protrusions 15a and 15b, as shown in the example in Figure 15. The imaging device 1 may have at least one of the reflection suppression film 23 and the stationary charge film described above. Also, for example, the imaging device 1 may have a configuration that does not have an insulating layer 50.

[0129] Figures 16 and 17 are diagrams illustrating another configuration example of the imaging device according to Modification 1. Figure 16 shows an example of the cross-sectional configuration of the imaging device, and Figure 17 shows an example of the planar configuration of the imaging device. Figure 16 corresponds, for example, to an example of the cross-sectional configuration of the imaging device in the direction of line A-A' shown in Figure 17. Note that the imaging device 1 may also have the planar configuration shown in Figure 18.

[0130] The semiconductor layer 10 is configured to have a plurality of protrusions 15 for each pixel P, as shown in the examples in Figures 16 to 18. The protrusions 15 (protrusions 15a, 15b) may have a rectangular shape. The protrusions 15a and 15b may have a structure in which the semiconductor layer 10 is binary processed. The protrusions 15a and 15b may be configured such that the amount of change in refractive index (i.e., the gradient of the effective refractive index) is maximized near the boundary between pixels P.

[0131] (Modification 2) Figures 19 and 20 are diagrams illustrating an example of the configuration of an imaging device according to Modification 2. In the imaging device 1, one light-gathering element 30 may be provided for multiple adjacent pixels P. For example, in the pixel section 100 of the imaging device 1, one light-gathering element 30 (for example, a lens 31) is provided for two adjacent pixels P.

[0132] In the examples shown in Figures 19 and 20, light that has passed through different regions of the optical system is received by the respective photoelectric conversion units 12 of two adjacent pixels P, and pupil division is performed. Phase difference data can be obtained by using the signal based on the charge converted by the photoelectric conversion unit 12 of one pixel P and the signal based on the charge converted by the photoelectric conversion unit 12 of the other pixel P. Phase difference autofocus can then be performed using this phase difference data.

[0133] Furthermore, the light-gathering element 30 may be placed for every two adjacent pixels P in the left-right direction (i.e., the X-axis direction), or for every two adjacent pixels P in the up-down direction (i.e., the Y-axis direction). As shown in Figure 21, the light-gathering element 30 may be provided for some of the pixels P, for example, adjacent pixels P of a specific color. For example, among pixels Pr, Pg, and Pb, pixel Pg (G pixel) may be configured as a phase-difference pixel.

[0134] Figure 22 is a diagram illustrating another configuration example of the imaging device according to Modification 2. The insulating film 25 may be formed to follow the convex portion 15 of each pixel P, as shown in the example in Figure 22. Note that the shape of the convex portion 15 is not limited to the illustrated example, and may be spherical, cylindrical, or other shapes.

[0135] (Modification 3) Figure 23 is a diagram illustrating an example of the configuration of an imaging device according to Modification 3. The light-gathering element 30 may be configured using a plurality of structures 35, as shown in the example in Figure 23. For example, the light-gathering element 30 is an optical element that focuses light using metamaterial (metasurface) technology and can be configured as a metalens.

[0136] Each structure 35 of the light-gathering element 30 may, for example, have a columnar shape and be constructed from a material having a refractive index different from that of the surrounding medium. Multiple structures 35 may, for example, be arranged in the X-axis direction or the Y-axis direction. The structures 35 are also referred to as, for example, nanopillars, nanostructures, nanoposts, etc.

[0137] (Modification 4) In the imaging device 1, each pixel P of each color may be provided with a protrusion 15 of a different shape from the others. For example, pixels Pr, Pg, and Pb may be arranged with protrusions 15 having different shapes (curvature, height, width, etc.). The imaging device 1 may be configured such that the curvature (radius of curvature), thickness, etc., of the protrusions 15a (or protrusions 15b) in each pixel P of each color are different in order to obtain the desired light-gathering characteristics for each pixel P of each color.

[0138] <2. Second Embodiment> Next, a second embodiment of the present disclosure will be described. In the following, components similar to those in the embodiments described above will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0139] Figures 24 to 26 are diagrams illustrating an example configuration of an imaging device according to a second embodiment of the present disclosure. The imaging device 1 may have pixels P provided with a light-shielding member 75 as phase-difference pixels. In the example shown in Figure 24, etc., pixels P of a specific color in the pixel section 100, for example, some pixels Pg (referred to as pixels Pg1 and pixels Pg2), have the light-shielding member 75. Note that multiple pixels Pg1 and Pg2 may be discretely arranged across the entire area of ​​the pixel section 100.

[0140] The light-shielding member 75 is a light-shielding portion (light-shielding film) composed of a light-blocking material, and is provided on the surface 11S1 side of the semiconductor layer 10. In the example shown in Figures 25 and 26, the light-shielding member 75 is provided on the insulating layer 50. The light-shielding member 75 is, as an example, made of a light-blocking metal material. The light-shielding member 75 may also be made of a light-absorbing material.

[0141] The light-shielding member 75 may be made of a metallic material such as tungsten, copper, aluminum, titanium, or titanium nitride, or it may be formed from other materials. The light-shielding member 75 may be made of the same material as the light-shielding member 71, or it may be made of a different material than the light-shielding member 71.

[0142] The light-shielding member 75 is provided, for example, between the light-collecting element 30 (e.g., lens 31) and the semiconductor layer 10 in pixel Pg1, and blocks a portion of the light that has passed through the light-collecting element 30. The light-shielding member 75 is also provided between the light-collecting element 30 and the semiconductor layer 10 in pixel Pg2, and blocks a portion of the light that has passed through the light-collecting element 30.

[0143] Pixel Pg1 and pixel Pg2 each have an aperture 76, as shown in the example in Figure 25 or Figure 26. The photoelectric conversion unit 12 of pixel Pg1 receives incident light through the light-collecting element 30, filter 40, and aperture 76, performs photoelectric conversion, and generates a charge corresponding to the amount of light received. The photoelectric conversion unit 12 of pixel Pg2 receives incident light through the light-collecting element 30, filter 40, and aperture 76, performs photoelectric conversion, and can generate a charge corresponding to the amount of light received.

[0144] In the examples shown in Figures 24 to 26, light that has passed through different regions of the optical system is received by pixels Pg1 and Pg2, and pupil division is performed. For example, the processing unit 114 of the imaging device 1 can obtain phase difference data by using the pixel signal based on the charge photoelectrically converted by pixel Pg1 and the pixel signal based on the charge photoelectrically converted by pixel Pg2. Phase difference autofocus can be performed using the phase difference data.

[0145] The protrusion 15 provided on the photoelectric conversion unit 12 of pixel Pg1 has its maximum thickness between the light-shielding member 75 and the boundary between pixel Pg1 and pixel Pr, as shown in the example in Figure 25. In pixel Pg1, the protrusion 15 is configured to have its maximum thickness between, for example, the light-shielding member 75 and the light-shielding member 71.

[0146] Furthermore, the protrusion 15 provided on the photoelectric conversion unit 12 of the pixel Pg2 has its maximum thickness between the light-shielding member 75 and the boundary between the pixel Pg2 and the pixel Pr, as shown in the example in Figure 26. In the pixel Pg2, the protrusion 15 is configured to have its maximum thickness between, for example, the light-shielding member 75 and the light-shielding member 71.

[0147] In the imaging device 1 according to this embodiment, the convex portion 15 is provided, allowing light to be appropriately guided to the photoelectric conversion unit 12, as schematically shown by the dashed arrow in Figure 27 or Figure 28. The convex portion 15 can appropriately guide light from the optical system, making it possible to reduce light scattering at the boundaries of the pixels P.

[0148] In the imaging device 1, the convex portion 15 allows for efficient collection of light from the phase-difference pixels (e.g., pixels Pg1, Pg2) to the photoelectric conversion unit 12. This suppresses a decrease in the accuracy of phase-difference detection and prevents a decline in AF performance. Furthermore, it suppresses the leakage of unwanted light to surrounding pixels P, thereby suppressing color mixing. It also suppresses the intrusion of noise into the pixel signal, thus suppressing a decline in image quality.

[0149] [Function and Effects] The photodetector according to this embodiment comprises a semiconductor layer (semiconductor layer 10), a photoelectric conversion region (photoelectric conversion section 12) provided in the semiconductor layer, a light-collecting element (light-collecting element 30) provided above the semiconductor layer, a protrusion (protrusion 15) provided above the photoelectric conversion region in the semiconductor layer into which light transmitted through the light-collecting element is incident, and a first light-shielding member (light-shielding member 75) provided between the light-collecting element and the semiconductor layer to shield a portion of the light transmitted through the light-collecting element.

[0150] In the light detection device (imaging device 1) according to this embodiment, a protrusion 15 is provided above the photoelectric conversion unit 12 in the semiconductor layer 10, into which light transmitted through the light-gathering element 30 is incident. This allows the incident light to be efficiently focused onto the photoelectric conversion unit 12. This makes it possible to realize a light detection device that can efficiently focus light.

[0151] Next, modified examples of the present disclosure will be described. In the following, components similar to those in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0152] (Modification 5) Figures 29 and 30 are diagrams illustrating an example of the configuration of an imaging device according to Modification 5 of the present disclosure. As shown in the example in Figures 29 and 30, a part of the protrusion 15 of the semiconductor layer 10 may be provided between the light-shielding member 75 and the photoelectric conversion unit 12. The protrusion 15 may be formed to cover, for example, the entire upper surface of the photoelectric conversion unit 12.

[0153] The protrusions 15 of the semiconductor layer 10 are provided such that they have their maximum thickness below the side surface of the light-shielding member 75, for example, as shown in the example in Figure 29 or Figure 30. In the case of the imaging device 1 according to this modified example, the incident light can be efficiently focused onto the photoelectric conversion unit 12. In this modified example, the same effects as in the above-described embodiment can be obtained.

[0154] <3. Examples of Application> The above-described imaging device 1 can be applied to any type of electronic device equipped with an imaging function, such as camera systems like digital still cameras and video cameras, or mobile phones with imaging capabilities. Figure 31 shows a schematic configuration of the electronic device 1000.

[0155] 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, all of which are interconnected via a bus line 1008.

[0156] The lens group 1001 captures incident light (image light) from the subject and forms an image on the imaging surface of the imaging device 1. The imaging device 1 converts the amount of incident light formed on the imaging surface by the lens group 1001 into an electrical signal on a pixel-by-pixel basis and supplies it as a pixel signal to the DSP circuit 1002.

[0157] The DSP circuit 1002 is a signal processing circuit that processes signals supplied from the imaging device 1. The DSP circuit 1002 outputs image data obtained by processing the signals from the imaging device 1. The frame memory 1003 temporarily holds the image data processed by the DSP circuit 1002 in frame units.

[0158] The display unit 1004 consists of, for example, a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and records the video or still image data captured by the imaging device 1 onto a recording medium such as a semiconductor memory or a hard disk.

[0159] The operation unit 1006 outputs operation signals for various functions possessed by the electronic device 1000 in accordance with user operations. The power supply unit 1007 appropriately supplies various power sources to the DSP circuit 1002, frame memory 1003, display unit 1004, recording unit 1005, and operation unit 1006.

[0160] <4. Application Examples> (Application Examples to Mobile Devices) The technology relating to this disclosure (this technology) can be applied to various products. For example, the technology relating to this disclosure may be implemented as a device mounted on any type of mobile device such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, and robots.

[0161] Figure 32 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technology described herein may be applied.

[0162] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 32, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. The functional configuration of the integrated control unit 12050 is shown in the figure, which includes a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network interface 12053.

[0163] The drivetrain control unit 12010 controls the operation of devices related to the vehicle's drivetrain according to various programs. For example, the drivetrain control unit 12010 functions as a control device for a drivetrain generating device that generates driving force for the vehicle, such as an internal combustion engine or a drive motor; a drivetrain transmission mechanism that transmits driving force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates braking force for the vehicle.

[0164] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window system, or various lamps such as headlights, reverse lights, brake lights, turn signals, or fog lights. In this case, the body system control unit 12020 may receive radio waves transmitted from a portable device that replaces a key or signals from various switches. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock system, power window system, lamps, etc.

[0165] The external information detection unit 12030 detects information from outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the imaging unit 12031 to capture images of the outside of the vehicle and receives the captured images. Based on the received images, the external information detection unit 12030 may perform object detection processing such as detecting people, cars, obstacles, signs, or characters on the road surface, or distance detection processing.

[0166] The imaging unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0167] The in-vehicle information detection unit 12040 detects information inside the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver status detection unit 12041 that detects the driver's state. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's level of fatigue or concentration, or determine whether the driver is drowsy, based on the detection information input from the driver status detection unit 12041.

[0168] The microcomputer 12051 can calculate control target values ​​for the drive force generator, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing ADAS (Advanced Driver Assistance System) functions, including collision avoidance or impact mitigation, following driving based on distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0169] Furthermore, the microcomputer 12051 can perform cooperative control for purposes such as autonomous driving, where the vehicle drives autonomously without driver intervention, by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the vehicle's surroundings acquired by the external information detection unit 12030 or the internal information detection unit 12040.

[0170] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on external information acquired by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of a preceding or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control aimed at reducing glare, such as switching from high beams to low beams.

[0171] The audio-image output unit 12052 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying information to the vehicle's occupants or to those outside the vehicle. In the example shown in Figure 32, the output devices include an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an onboard display and a head-up display.

[0172] Figure 33 shows an example of the installation position of the imaging unit 12031.

[0173] In Figure 33, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0174] The imaging units 12101, 12102, 12103, 12104, and 12105 are installed, for example, on the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle 12100. The imaging unit 12101 installed on the front nose and the imaging unit 12105 installed on the upper part of the windshield inside the vehicle mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 installed on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 installed on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 installed on the upper part of the windshield inside the vehicle is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes.

[0175] Figure 33 shows an example of the imaging ranges of imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of imaging unit 12101 located on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of imaging units 12102 and 12103 located on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of imaging unit 12104 located on the rear bumper or back door. For example, by superimposing the image data captured by imaging units 12101 to 12104, an overhead view image of the vehicle 12100 can be obtained.

[0176] At least one of the imaging units 12101 to 12104 may have a function for acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple image sensors, or an image sensor having pixels for phase difference detection.

[0177] For example, the microcomputer 12051, based on distance information obtained from the imaging units 12101 to 12104, can determine the distance to each object within the imaging range 12111 to 12114 and the temporal change of this distance (relative speed to the vehicle 12100). In particular, it can extract the closest object on the vehicle 12100's path that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or more) as the preceding vehicle. Furthermore, the microcomputer 12051 can set a predetermined distance to be maintained before the preceding vehicle and perform automatic braking control (including follow-and-stop control) and automatic acceleration control (including follow-and-start control), etc. In this way, cooperative control aimed at autonomous driving, where the vehicle drives autonomously without driver intervention, can be performed.

[0178] For example, the microcomputer 12051 can use distance information obtained from imaging units 12101 to 12104 to classify and extract three-dimensional object data related to three-dimensional objects, such as motorcycles, passenger cars, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and use this data for automatic obstacle avoidance. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle. If the collision risk is above a set value and there is a possibility of collision, the microcomputer 12051 can provide driving assistance to avoid collisions by outputting a warning to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or evasive steering via the drive system control unit 12010.

[0179] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared light. For example, the microcomputer 12051 can recognize pedestrians by determining whether or not pedestrians are present in the images captured by the imaging units 12101 to 12104. Such pedestrian recognition is performed, for example, by a procedure to extract feature points from the images captured by the imaging units 12101 to 12104 as infrared cameras, and a procedure to perform pattern matching on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the imaging units 12101 to 12104 and recognizes a pedestrian, the audio-image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio-image output unit 12052 may also control the display unit 12062 to display an icon indicating a pedestrian at a desired position.

[0180] The above describes an example of a mobile control system to which the technology described herein can be applied. The technology described herein can be applied to, for example, the imaging unit 12031 of the configuration described above. Specifically, for example, the imaging device 1 can be applied to the imaging unit 12031. By applying the technology described herein to the imaging unit 12031, it becomes possible to obtain high-definition captured images. This makes it possible to perform high-precision control using captured images in the mobile control system.

[0181] (Examples of application to endoscopic surgical systems) The technology described herein (the technology) can be applied to various products. For example, the technology described herein may be applied to endoscopic surgical systems.

[0182] Figure 34 is a diagram showing an example of a schematic configuration of an endoscopic surgical system to which the technology described herein (the technology) may be applied.

[0183] Figure 34 illustrates a surgeon (physician) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgical system 11000. As shown in the figure, the endoscopic surgical system 11000 consists of an endoscope 11100, other surgical instruments 11110 such as an insufflation tube 11111 and an energy treatment device 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 equipped with various devices for endoscopic surgery.

[0184] The endoscope 11100 consists of a barrel 11101, the tip of which is inserted into the body cavity of the patient 11132 for a predetermined length, and a camera head 11102 connected to the base end of the barrel 11101. In the illustrated example, the endoscope 11100 is shown as a so-called rigid endoscope having a rigid barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible endoscope having a flexible barrel.

[0185] An opening into which an objective lens is fitted is provided at the tip of the microscope tube 11101. A light source device 11203 is connected to the endoscope 11100, and the light generated by the light source device 11203 is guided to the tip of the microscope tube by a light guide extending inside the microscope tube 11101, and is irradiated through the objective lens towards the object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a straight-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0186] The camera head 11102 contains an optical system and an image sensor. Reflected light from the object being observed (observation light) is focused onto the image sensor by the optical system. The image sensor converts the observation light into electrical signals, generating an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. This image signal is transmitted as RAW data to the camera control unit (CCU) 11201.

[0187] The CCU 11201 is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and other components, and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various image processing operations on that image signal, such as development processing (demosaic processing), to display the image based on that image signal.

[0188] The display device 11202 displays an image based on an image signal that has been processed by the CCU 11201, under control from the CCU 11201.

[0189] The light source device 11203 consists of a light source such as an LED (Light Emitting Diode) and supplies illumination light to the endoscope 11100 when photographing the surgical area, etc.

[0190] The input device 11204 is an input interface for the endoscopic surgical system 11000. The user can input various types of information and instructions to the endoscopic surgical system 11000 via the input device 11204. For example, the user can input instructions to change the imaging conditions (type of light, magnification, focal length, etc.) of the endoscope 11100.

[0191] The treatment instrument control device 11205 controls the drive of the energy treatment instrument 11112 for purposes such as tissue cauterization, incision, or blood vessel sealing. The insufflation device 11206 injects gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing a field of view by the endoscope 11100 and securing the operator's workspace. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, images, or graphs.

[0192] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical area can be configured as a white light source consisting of, for example, an LED, a laser light source, or a combination thereof. When the white light source is configured as a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in time-division by irradiating the observation target with laser light from each of the RGB laser light sources in time-division and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter on the image sensor.

[0193] Furthermore, the light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the drive of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity, images can be acquired in time-division order, and these images can be combined to generate high dynamic range images without so-called black crushing and white clipping.

[0194] Furthermore, the light source device 11203 may be configured to 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 tissue and irradiating with narrow-band light compared to the irradiation light used in normal observation (i.e., white light), so-called narrow-band imaging is performed to image predetermined tissues such as blood vessels on the surface of mucosa with high contrast. Alternatively, in special light observation, fluorescence observation may be performed to obtain an image from fluorescence generated by irradiation with excitation light. In fluorescence observation, excitation light is irradiated onto body tissue and fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is injected into body tissue and excitation light corresponding to the fluorescence wavelength of the reagent is irradiated onto the body tissue to obtain a fluorescence image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0195] Figure 35 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in Figure 34.

[0196] The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0197] The lens unit 11401 is an optical system provided at the connection point with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and then incident on the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses, including a zoom lens and a focus lens.

[0198] The imaging unit 11402 is composed of image sensors. The imaging unit 11402 may consist of one image sensor (a so-called single-chip type) or multiple image sensors (a so-called multi-chip type). If the imaging unit 11402 is composed of multiple chips, for example, each image sensor may generate image signals corresponding to RGB, and these may be combined to obtain a color image. Alternatively, the imaging unit 11402 may be configured to have a pair of image sensors for acquiring image signals for the right eye and left eye, respectively, corresponding to 3D (Dimensional) display. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical area. In addition, if the imaging unit 11402 is composed of multiple chips, multiple lens units 11401 may also be provided corresponding to each image sensor.

[0199] Furthermore, the imaging unit 11402 does not necessarily have to be located on the camera head 11102. For example, the imaging unit 11402 may be located inside the lens barrel 11101, directly behind the objective lens.

[0200] The drive unit 11403 is composed of actuators and, under control from the camera head control unit 11405, moves the zoom lens and focus lens of the lens unit 11401 along the optical axis by a predetermined distance. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted as appropriate.

[0201] The communication unit 11404 is composed of communication devices for sending and receiving various types of information with the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0202] Furthermore, the communication unit 11404 receives a control signal from the CCU 11201 to control the drive of the camera head 11102 and supplies it to the camera head control unit 11405. The control signal includes information about imaging conditions, such as information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and / or information to specify the magnification and focus of the captured image.

[0203] The imaging conditions such as frame rate, exposure value, magnification, and focus may be specified by the user as appropriate, or they may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 will be equipped with so-called AE (Auto Exposure), AF (Auto Focus), and AWB (Auto White Balance) functions.

[0204] The camera head control unit 11405 controls the drive of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0205] The communication unit 11411 is comprised of a communication device for sending and receiving various types of information with the camera head 11102. The communication unit 11411 receives image signals transmitted from the camera head 11102 via the transmission cable 11400.

[0206] Furthermore, the communication unit 11411 transmits control signals to the camera head 11102 to control the driving of the camera head 11102. Image signals and control signals can be transmitted by telecommunications, optical communications, etc.

[0207] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102.

[0208] The control unit 11413 performs various controls related to imaging the surgical area, etc., by the endoscope 11100, and the display of the images obtained from imaging the surgical area, etc. For example, the control unit 11413 generates a control signal to control the driving of the camera head 11102.

[0209] Furthermore, the control unit 11413 displays the captured image showing the surgical area, etc., on the display device 11202 based on the image signal processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical instruments such as forceps, specific biological sites, bleeding, mist when using the energy treatment device 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When the control unit 11413 displays the captured image on the display device 11202, it may use the recognition results to superimpose various surgical support information onto the image of the surgical area. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can proceed with the surgery reliably.

[0210] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable thereof.

[0211] In the illustrated example, communication was performed via a wired connection using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may be performed wirelessly.

[0212] The above describes an example of an endoscopic surgical system to which the technology described herein may be applied. The technology described herein can be suitably applied, for example, to the imaging unit 11402 provided on the camera head 11102 of the endoscope 11100. By applying the technology described herein to the imaging unit 11402, it becomes possible to provide a high-definition endoscope 11100.

[0213] Although the present disclosure has been described above with reference to embodiments, modifications, application examples, and application examples, the present technology is not limited to the above embodiments, and various modifications are possible. For example, although the above modifications were described as modifications of the above embodiments, the configurations of each modification can be combined as appropriate.

[0214] In the embodiments described above, an imaging device was used as an example; however, the light detection device of this disclosure may be any device that receives incident light and converts the light into an electric charge. The output signal may be an image information signal or a distance measurement information signal. The light detection device (imaging device) can be applied to an image sensor, a distance measurement sensor, etc. Furthermore, this disclosure is not limited to back-illuminated image sensors, but is also applicable to front-illuminated image sensors.

[0215] The light detection device relating to this disclosure can also be used as a distance measuring sensor capable of measuring distance using the Time of Flight (TOF) method. The light detection device (imaging device) can also be used as a sensor capable of detecting events, for example, an event-driven sensor (also known as an EVS (Event Vision Sensor), EDS (Event Driven Sensor), DVS (Dynamic Vision Sensor), etc.).

[0216] An embodiment of the present disclosure of a photodetector comprises a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light-gathering element provided above the semiconductor layer. The semiconductor layer has a first protrusion provided between the light-gathering element and the first photoelectric conversion region. This makes it possible to realize a photodetector capable of efficiently focusing light.

[0217] An optical detection device according to one embodiment of the present disclosure comprises a semiconductor layer, a photoelectric conversion region provided in the semiconductor layer, a light-collecting element provided above the semiconductor layer, a convex portion provided above the photoelectric conversion region in the semiconductor layer, into which light transmitted through the light-collecting element is incident, and a first light-shielding member provided between the light-collecting element and the semiconductor layer, which shields a portion of the light transmitted through the light-collecting element. This makes it possible to realize an optical detection device that can efficiently collect light.

[0218] Furthermore, the effects described herein are merely illustrative and not limited to those described herein, and other effects may also exist. In addition, this disclosure may take the following configurations: (1) A photodetector comprising a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light-gathering element provided above the semiconductor layer, wherein the semiconductor layer has a first protrusion provided between the light-gathering element and the first photoelectric conversion region. (2) The photodetector according to (1), comprising a first pixel having the first photoelectric conversion region and the second photoelectric conversion region, and a second pixel adjacent to the first pixel, wherein the first protrusion has its maximum thickness between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the first pixel and the second pixel. (3) The photodetector according to (1) or (2), comprising a first pixel having the first photoelectric conversion region and the second photoelectric conversion region, and a second pixel adjacent to the first pixel, wherein the thickness of the semiconductor layer in the first pixel is greatest between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the first pixel and the second pixel. (4) The photodetector according to any one of (1) to (3), wherein the first photoelectric conversion region photoelectrically converts light incident via the light-gathering element and the first protrusion. (5) The photodetector according to any one of (1) to (4), wherein the semiconductor layer has a second protrusion provided between the light-gathering element and the second photoelectric conversion region, and the second photoelectric conversion region photoelectrically converts light incident via the light-gathering element and the second protrusion. (6) The photodetector according to any one of (1) to (5) above, comprising a first pixel having at least one of the first photoelectric conversion region and the second photoelectric conversion region, wherein the first pixel is a pixel usable for phase difference detection.(7) The photodetector according to any one of (1) to (6), comprising a first pixel having the first photoelectric conversion region, a second pixel having the second photoelectric conversion region and adjacent to the first pixel, and a third pixel adjacent to the second pixel, wherein the first protrusion has the greatest thickness between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the second pixel and the third pixel. (8) The photodetector according to any one of (1) to (7), wherein the first protrusion has a spherical shape. (9) The photodetector according to any one of (1) to (7), wherein the first protrusion has a cylindrical shape. (10) The photodetector according to any one of (1) to (9), wherein the semiconductor layer has a plurality of first protrusions provided between the light-gathering element and the first photoelectric conversion region. (11) The light detection device according to any one of (1) to (10), further comprising an insulating film provided so as to cover the first protrusion and having a refractive index lower than that of the first protrusion. (12) The light detection device according to any one of (1) to (11), wherein the light-gathering element is a lens for focusing light. (13) The light detection device according to any one of (1) to (12), further comprising a filter provided between the light-gathering element and the first photoelectric conversion region, wherein the first photoelectric conversion region photoelectrically converts light incident through the light-gathering element, the filter and the first protrusion. (14) The photodetector according to any one of (1) to (13), comprising: a first pixel having a first photoelectric conversion region for receiving light of a first wavelength; and a second pixel adjacent to the first pixel having a second photoelectric conversion region for receiving light of a second wavelength, wherein the semiconductor layer has a first protrusion provided with respect to the first photoelectric conversion region and a second protrusion provided with respect to the second photoelectric conversion region, and the first protrusion and the second protrusion have different shapes from each other.(15) A light detection device comprising: a semiconductor layer; a photoelectric conversion region provided in the semiconductor layer; a light-gathering element provided above the semiconductor layer; a convex portion provided above the photoelectric conversion region in the semiconductor layer, into which light transmitted through the light-gathering element is incident; and a first light-shielding member provided between the light-gathering element and the semiconductor layer, which shields a portion of the light transmitted through the light-gathering element. (16) The light detection device according to (15), comprising a first pixel and a second pixel, each having the photoelectric conversion region, wherein the convex portion has the greatest thickness between the first light-shielding member and the boundary between the first pixel and the second pixel. (17) The light detection device according to (15) or (16), further comprising a plurality of pixels, each having the photoelectric conversion region, and a second light-shielding member provided at the boundary between a plurality of adjacent pixels, wherein the convex portion has the greatest thickness between the first light-shielding member and the second light-shielding member. (18) The photodetector according to any one of (15) to (17), wherein a part of the protrusion is provided between the first light-shielding member and the photoelectric conversion region. (19) The photodetector according to (18), wherein the protrusion has the greatest thickness below the side surface of the first light-shielding member. (20) An electronic device comprising an optical system and a photodetector that receives light transmitted through the optical system, wherein the photodetector has a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light-gathering element provided above the semiconductor layer, wherein the semiconductor layer has a first protrusion provided between the light-gathering element and the first photoelectric conversion region. (21) Electronic device comprising an optical system and a light detection device for receiving light transmitted through the optical system, wherein the light detection device comprises a semiconductor layer, a photoelectric conversion region provided in the semiconductor layer, a light-collecting element provided above the semiconductor layer, a convex portion provided above the photoelectric conversion region in the semiconductor layer for which light transmitted through the light-collecting element is incident, and a first light-shielding member provided between the light-collecting element and the semiconductor layer for shielding a portion of the light transmitted through the light-collecting element.

[0219] This application claims priority based on Japanese Patent Application No. 2024-166490, filed with the Japan Patent Office on 25 September 2024, and all contents of that application are incorporated herein by reference.

[0220] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A photodetector comprising a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light-gathering element provided above the semiconductor layer, wherein the semiconductor layer has a first protrusion provided between the light-gathering element and the first photoelectric conversion region.

2. The photodetector according to claim 1, comprising a first pixel having a first photoelectric conversion region and a second photoelectric conversion region, and a second pixel adjacent to the first pixel, wherein the first protrusion has its maximum thickness between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the first pixel and the second pixel.

3. The photodetector according to claim 1, comprising a first pixel having a first photoelectric conversion region and a second photoelectric conversion region, and a second pixel adjacent to the first pixel, wherein the thickness of the semiconductor layer in the first pixel is maximized between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the first pixel and the second pixel.

4. The photodetector according to claim 1, wherein the first photoelectric conversion region converts light incident via the light-collecting element and the first protrusion into photoelectric form.

5. The photodetector according to claim 1, wherein the semiconductor layer has a second protrusion provided between the light-gathering element and the second photoelectric conversion region, and the second photoelectric conversion region photoelectrically converts light incident on the light-gathering element and the second protrusion.

6. The photodetector according to claim 1, comprising a first pixel having at least one of the first photoelectric conversion region and the second photoelectric conversion region, wherein the first pixel is a pixel usable for phase difference detection.

7. The photodetector according to claim 1, comprising a first pixel having a first photoelectric conversion region, a second pixel having a second photoelectric conversion region and adjacent to the first pixel, and a third pixel adjacent to the second pixel, wherein the first protrusion has its maximum thickness between the boundary between the first photoelectric conversion region and the second photoelectric conversion region and the boundary between the second pixel and the third pixel.

8. The photodetector according to claim 1, wherein the first convex portion has a spherical shape.

9. The photodetector according to claim 1, wherein the first protrusion has a cylindrical shape.

10. The photodetector according to claim 1, wherein the semiconductor layer has a plurality of first protrusions provided between the light-collecting element and the first photoelectric conversion region.

11. The photodetector according to claim 1, further comprising an insulating film provided so as to cover the first protrusion and having a refractive index lower than that of the first protrusion.

12. The light detection device according to claim 1, wherein the light-gathering element is a lens that focuses light.

13. The photodetector according to claim 1, further comprising a filter provided between the light-collecting element and the first photoelectric conversion region, wherein the first photoelectric conversion region photoelectrically converts light incident via the light-collecting element, the filter, and the first protrusion.

14. The photodetector according to claim 1, comprising: a first pixel having a first photoelectric conversion region for receiving light of a first wavelength; and a second pixel adjacent to the first pixel having a second photoelectric conversion region for receiving light of a second wavelength, wherein the semiconductor layer has a first protrusion provided with respect to the first photoelectric conversion region and a second protrusion provided with respect to the second photoelectric conversion region, and the first protrusion and the second protrusion have different shapes from each other.

15. A light detection device comprising: a semiconductor layer; a photoelectric conversion region provided in the semiconductor layer; a light-collecting element provided above the semiconductor layer; a convex portion provided above the photoelectric conversion region in the semiconductor layer, into which light transmitted through the light-collecting element is incident; and a first light-shielding member provided between the light-collecting element and the semiconductor layer, which shields a portion of the light transmitted through the light-collecting element.

16. The light detection device according to claim 15, comprising a first pixel and a second pixel, each having the photoelectric conversion region, wherein the protrusion has the maximum thickness between the first light-shielding member and the boundary between the first pixel and the second pixel.

17. The photodetector according to claim 15, further comprising a plurality of pixels each having the photoelectric conversion region, and a second light-shielding member provided at the boundary between a plurality of adjacent pixels, wherein the protrusion has the maximum thickness between the first light-shielding member and the second light-shielding member.

18. The light detection device according to claim 15, wherein a portion of the protrusion is provided between the first light-shielding member and the photoelectric conversion region.

19. The light detection device according to claim 18, wherein the protrusion has its greatest thickness below the side surface of the first light-shielding member.

20. An electronic device comprising an optical system and a photodetector that receives light transmitted through the optical system, wherein the photodetector has a semiconductor layer, a first photoelectric conversion region and a second photoelectric conversion region provided adjacent to each other in the semiconductor layer, and a light-gathering element provided above the semiconductor layer, wherein the semiconductor layer has a first protrusion provided between the light-gathering element and the first photoelectric conversion region.

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