Light detection device

Abstract

A first light detection device according to one embodiment of the present disclosure comprises: a semiconductor substrate that has a first surface and a second surface facing each other and has a photoelectric conversion unit for each pixel; a light guide unit that is provided on the first surface side of the semiconductor substrate and includes a plurality of structures each having a size equal to or less than the wavelength of incident light and a medium provided so as to fill the space between adjacent ones of the plurality of structures and having a refractive index different from the refractive index of the plurality of structures; a spacer layer including an organic layer and an inorganic layer laminated in order from the semiconductor substrate side between the semiconductor substrate and the light guide unit; a separation groove that is provided so as to surround the plurality of structures in plan view, separates at least the organic layer, and exposes the semiconductor substrate on the bottom surface; and a protective film extending at least on the side surface and the bottom surface of the separation groove.

Description

Light detection device

[0001] This disclosure relates to a photodetector having a wavelength separation structure.

[0002] For example, Patent Document 1 discloses an example in which the reliability of the light-gathering design is improved by providing a sidewall protective film on the sidewall of the spacer layer in a photodetector in which a spacer layer and a metasurface layer are stacked in that order on a semiconductor substrate having a photoelectric conversion unit.

[0003] International Publication No. 2024 / 057950

[0004] Thus, in light detection devices, there is a need to improve the reliability of the light-gathering design.

[0005] It is desirable to provide an optical detection device that can improve reliability.

[0006] A first photodetector as one embodiment of the present disclosure comprises a semiconductor substrate having opposing first and second surfaces and a photoelectric conversion unit for each pixel; a light guide unit provided on the first surface side of the semiconductor substrate and provided to fill the spaces between a plurality of structures, each having a size less than or equal to the wavelength of incident light, and containing a medium having a refractive index different from that of the plurality of structures; a spacer layer containing an organic layer and an inorganic layer laminated sequentially from the semiconductor substrate side between the semiconductor substrate and the light guide unit; a separation groove provided so as to surround the plurality of structures in a plan view, separating at least the organic layer and exposing the semiconductor substrate at the bottom surface; and a protective film extending at least to the side surface and bottom surface of the separation groove.

[0007] In a first photodetector as one embodiment of the present disclosure, a spacer layer containing organic and inorganic layers stacked sequentially from the semiconductor substrate side is provided between a semiconductor substrate having a photoelectric conversion unit and a light guide unit, and a separation groove is provided to separate at least the organic layer. In a plan view, the separation groove is provided so as to surround a plurality of structures provided in the light guide unit, with the semiconductor substrate exposed at its bottom surface, and its sides and bottom surface covered by a protective film. This reduces the intrusion of moisture through the organic layer and prevents misalignment of the light guide unit caused by the stacking of the organic and inorganic layers.

[0008] A second photodetector as one embodiment of the present disclosure comprises a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, with a photoelectric conversion portion provided between a first surface and a second surface facing each pixel; a light guide portion provided on the first surface side of the semiconductor substrate and containing a medium having a refractive index different from that of the plurality of structures, each having a size less than or equal to the wavelength of incident light and provided to fill the space between adjacent plurality of structures; a spacer layer containing an organic layer and an inorganic layer stacked sequentially from the semiconductor substrate side between the semiconductor substrate and the light guide portion; and a stepped portion provided between the semiconductor substrate and the spacer layer in the peripheral portion.

[0009] In a second photodetector as one embodiment of the present disclosure, a step is provided in the peripheral portion between a semiconductor substrate having a photoelectric conversion unit and a spacer layer in which organic and inorganic layers are stacked in order from the semiconductor substrate side. This prevents misalignment of the light guide unit caused by the difference in thermal expansion coefficients between the organic and inorganic layers.

[0010] A third photodetector as one embodiment of the present disclosure comprises a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, with a photoelectric conversion portion provided between a first surface and a second surface facing each pixel, and a light guide portion provided on the first surface side of the semiconductor substrate, each having a size less than or equal to the wavelength of incident light and provided to fill the space between adjacent plurality of structures, containing a medium having a refractive index different from that of the plurality of structures, and having a depression in the peripheral portion, and a filling layer that fills the depression.

[0011] In a third light detection device as one embodiment of the present disclosure, the recesses in the light guide portion provided in the peripheral area are filled with an embedding layer to flatten the surface. This prevents the formation of high-refractive index material layers constituting multiple structures in the recesses.

[0012] Figure 1 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to the first embodiment of this disclosure. Figure 2 is a block diagram showing an example of the schematic configuration of the photodetector shown in Figure 1. Figure 3 is a schematic diagram showing an example of the pixel array and its surroundings of the photodetector shown in Figure 1. Figure 4 is a diagram showing an example of the circuit configuration of a unit pixel of the photodetector shown in Figure 1. Figure 5A is a schematic cross-sectional diagram showing an example of the manufacturing process of the photodetector shown in Figure 1. Figure 5B is a schematic cross-sectional diagram showing the process following Figure 5A. Figure 5C is a schematic cross-sectional diagram showing the process following Figure 5B. Figure 5D is a schematic cross-sectional diagram showing the process following Figure 5C. Figure 5E is a schematic cross-sectional diagram showing the process following Figure 5D. Figure 5F is a schematic cross-sectional diagram showing the process following Figure 5E. Figure 5G is a schematic cross-sectional diagram showing the process following Figure 5F. Figure 6 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector as Comparative Example 1. Figure 7 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector as Comparative Example 2. Figure 8 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 1 of the present disclosure. Figure 9 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to the second embodiment of the present disclosure. Figure 10A is a schematic cross-sectional diagram showing an example of the manufacturing process of the photodetector shown in Figure 9. Figure 10B is a schematic cross-sectional diagram showing the process following Figure 10A. Figure 10C is a schematic cross-sectional diagram showing the process following Figure 10B. Figure 10D is a schematic cross-sectional diagram showing the process following Figure 10C. Figure 10E is a schematic cross-sectional diagram showing the process following Figure 10D. Figure 10F is a schematic cross-sectional diagram showing the process following Figure 10E. Figure 11 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 2 of the present disclosure. Figure 12 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 3 of the present disclosure. Figure 13 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to the third embodiment of the present disclosure. Figure 14 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 4 of the present disclosure. Figure 15 is a schematic diagram showing an example of the pixel array portion and its surroundings of the photodetector shown in Figure 14. Figure 16 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 5 of this disclosure. Figure 17 is a functional block diagram showing an example of an electronic device (camera) using the photodetector shown in Figure 2. Figure 18A is a schematic diagram showing an example of the overall configuration of a photodetector system using the photodetector shown in Figure 2.Figure 18B is a diagram showing an example of the circuit configuration of the photodetection system shown in Figure 18A. Figure 19 is a diagram showing an example of the schematic configuration of an endoscopic surgical system. Figure 20 is a block diagram showing an example of the functional configuration of a camera head and a CCU. Figure 21 is a block diagram showing an example of the schematic configuration of a vehicle control system. Figure 22 is an explanatory diagram showing an example of the installation position of the external information detection unit and the imaging unit. Figure 23 is a schematic cross-sectional diagram showing an example of the configuration of a photodetection device according to the fourth embodiment of this disclosure. Figure 24 is a schematic cross-sectional diagram showing an example of the configuration of a photodetection device according to the fifth embodiment of this disclosure. Figure 25 is a schematic diagram showing an example of the pixel array and its surroundings of the photodetection device shown in Figure 24. Figure 26 is a schematic cross-sectional diagram showing an example of the configuration of a photodetection device according to modification 6 of this disclosure. Figure 27 is a schematic cross-sectional diagram showing an example of the configuration of a photodetection device according to the sixth embodiment of this disclosure. Figure 28 is a schematic cross-sectional diagram showing another example of the configuration of a photodetection device according to the sixth embodiment of this disclosure. Figure 29A is a schematic cross-sectional diagram showing an example of the manufacturing process of the photodetection device shown in Figure 27. Figure 29B is a schematic cross-sectional diagram showing the process following Figure 29A. Figure 29C is a schematic cross-sectional diagram showing the process following Figure 29B. Figure 29D is a schematic cross-sectional diagram showing the process following Figure 29C. Figure 29E is a schematic cross-sectional diagram showing the process following Figure 29D. Figure 29F is a schematic cross-sectional diagram showing the process following Figure 29E. Figure 29G is a schematic cross-sectional diagram showing the process following Figure 29F. Figure 29H is a schematic cross-sectional diagram showing the process following Figure 29G. Figure 30 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 7 of this disclosure. Figure 31 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 8 of this disclosure. Figure 32 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 9 of this disclosure. Figure 33 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to the seventh embodiment of this disclosure. Figure 34 is a schematic diagram showing an example of the pixel array portion and its surroundings of the photodetector shown in Figure 33. Figure 35 is a schematic diagram showing another example of the pixel array portion and surrounding area of ​​the photodetector shown in Figure 33. Figure 36 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 10 of the present disclosure. Figure 37 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 11 of the present disclosure.Figure 38 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 12 of the present disclosure. Figure 39 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to the eighth embodiment of the present disclosure. Figure 40A is a schematic cross-sectional diagram showing an example of the manufacturing process of the photodetector shown in Figure 39. Figure 40B is a schematic cross-sectional diagram showing the process following Figure 40A. Figure 40C is a schematic cross-sectional diagram showing the process following Figure 40B. Figure 40D is a schematic cross-sectional diagram showing the process following Figure 40C. Figure 40E is a schematic cross-sectional diagram showing the process following Figure 40D. Figure 40F is a schematic cross-sectional diagram showing the process following Figure 40E. Figure 40G is a schematic cross-sectional diagram showing the process following Figure 40F. Figure 41 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 13 of the present disclosure. Figure 42 is a schematic cross-sectional diagram showing an example of the configuration of a photodetector according to Modification 14 of the present disclosure.

[0013] The embodiments described below will be explained in detail with reference to the drawings. The following description is one specific example of the disclosure, and the disclosure is not limited to the following embodiments. Furthermore, the disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc., of each component shown in each drawing. The order of explanation is as follows.1. First Embodiment (Example of a photodetector having a separation groove in the peripheral portion that separates the spacer layer and is embedded by a medium constituting the light guide portion) 2. Modification 1 (Another example of the configuration of a photodetector) 3. Second Embodiment (Example of a photodetector having a separation groove in the peripheral portion that separates the organic layer of a spacer layer formed by sequentially stacking an organic layer and an inorganic layer from the semiconductor substrate side and is embedded by an inorganic layer) 4. Modification 4-1. Modification 2 (Another example of the configuration of a photodetector) 4-2. Modification 3 (Another example of the configuration of a photodetector) 5. Third Embodiment (Example of a photodetector with a color filter extending to the peripheral portion) 6. Modification 6-1. Modification 4 (Another example of the configuration of a photodetector) 6-2. Modification 5 (Another example of the configuration of a photodetector) 7. Fourth Embodiment (Example of a photodetector further having separation grooves in the pad portion and scribe portion) 8. 9. Modification 9-1. Modification 6 (Another example of the configuration of the photodetector) 10. Modification 6 (Another example of the configuration of the photodetector) 11. Modification 11-1. Modification 7 (Another example of the configuration of the photodetector) 11-2. Modification 8 (Another example of the configuration of the photodetector) 11-3. Modification 9 (Another example of the configuration of the photodetector) 12. Modification 7 (Another example of the configuration of the photodetector) 13. Modification 13-1. Modification 10 (Another example of the configuration of the photodetector) 13-2. Modification 11 (Another example of the configuration of the photodetector) 13-3. Modification 12 (Another example of the configuration of the photodetector) 14. Eighth Embodiment (Example of a photodetector in which an embedded layer is provided on the light guide portion of the peripheral edge forming a depression, and the surface is flattened) 15. Modifications 15-1. Modification 13 (Another example of the configuration of a photodetector) 15-2. Modification 14 (Another example of the configuration of a photodetector) 16. Application Examples 17. Application examples.

[0014] <1. First Embodiment> Figure 1 schematically shows an example of the cross-sectional configuration of a photodetector (photodetector 1) according to the first embodiment of the present disclosure. Figure 2 is a block diagram showing an example of the schematic configuration of the photodetector 1 shown in Figure 1. Figure 3 schematically shows an example of the configuration of the pixel array section 100A and its surroundings of the photodetector 1 shown in Figure 1. The photodetector 1 is applicable to, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital still cameras and video cameras, and has a pixel array section (pixel array section 100A) in which a plurality of pixels are arranged in a matrix in two dimensions as an imaging area. The photodetector 1 is, for example, a so-called back-illuminated type photodetector in this CMOS image sensor.

[0015] [Outline Configuration of the Light Detection Device] The light detection device 1 captures incident light (image light) from a subject via an optical lens system (for example, optical system 1001, see Figure 17), converts the amount of light of the incident light imaged on the imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs it as a pixel signal. The light detection device 1 has a pixel array section 100A as an imaging area on a semiconductor substrate 11, and a peripheral section 100B around this pixel array section 100A. The peripheral section 100B includes, for example, a pixel control section 111, a signal processing section 112, a control section 113, and a processing section 114. The light detection device 1 is also provided with, for example, a plurality of control lines Lread and a plurality of signal lines VSL.

[0016] In the pixel array section 100A, for example, multiple unit pixels P are arranged in a matrix in a two-dimensional manner. For example, control lines Lread (specifically row selection lines and reset control lines) are wired to each pixel row of unit pixels P, and signal lines VSL are wired to each pixel column.

[0017] The control line Lread is a signal line capable of transmitting signals to control a unit pixel P, and is connected to the pixel control unit 111 and the unit pixel P of the pixel array unit 100A. The control line Lread is configured to transmit control signals for reading signals from the unit pixel P. The control line Lread can also be called a drive line (pixel drive line) that transmits signals to drive the unit pixel P.

[0018] A signal line VSL is a signal line capable of transmitting signals from a unit pixel P, and is connected to the unit pixel P of the pixel array section 100A and the signal processing section 112. In the pixel array section 100A, for example, one or more signal lines VSL are wired to each pixel row, which is composed of multiple unit pixels P arranged vertically (in the column direction). The signal lines VSL are configured to transmit signals output from the unit pixels P. In the photodetector 1, multiple signal lines VSL may be provided for a single pixel row.

[0019] The pixel control unit 111 is configured to control each unit pixel P of the pixel array unit 100A. 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 unit pixel P and outputs it to each unit pixel P of the pixel array unit 100A via the control line Lread. The pixel control unit 111 is controlled by the control unit 113 and controls the unit pixels P of the pixel array unit 100A.

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

[0021] The signal processing unit 112 is configured to perform processing of the input pixel signal. The signal processing unit 112 is a signal processing circuit and includes, for example, a load circuit, an analog-to-digital (AD) conversion circuit, and a horizontal selection switch. The load circuit is, for example, composed of a current source capable of supplying current to the amplification transistor of a unit pixel P. The load circuit, together with the amplification transistor of the unit pixel P, constitutes a source follower circuit.

[0022] The signal processing unit 112 may have an amplification circuit configured to amplify the signal read from the unit pixel P via the signal line VSL. Load circuits, amplification circuits, and AD conversion circuits, etc., are provided, for example, for each of the multiple signal lines VSL. Load circuits, amplification circuits, and AD conversion circuits, etc., may be provided for each pixel row of the pixel array unit 100A.

[0023] The signals output from each unit 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 correlated double sampling (CDS) of the unit pixel P signals. The signals of each unit pixel P transmitted through each of the signal lines VSL are processed by the signal processing unit 112 and output to the processing unit 114.

[0024] The processing unit 114 is configured to perform signal processing on the input signal. The processing unit 114 is a processing circuit and is composed of, for example, a circuit that performs various signal processing on the pixel signal. The processing unit 114 may also include a processor and memory. The processing unit 114 performs signal processing on the pixel signal input from the signal processing unit 112 and outputs the processed pixel signal. The processing unit 114 can perform various signal processing, such as noise reduction processing and gradation correction processing.

[0025] The control unit 113 is configured to control each part of the light detection 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 light detection device 1. The control unit 113 is a control circuit and, for example, has a timing generator configured to generate various timing signals. Based on the various timing signals (pulse signals, clock signals, etc.) generated by the timing generator, the control unit 113 performs drive control of the pixel control unit 111 and the signal processing unit 112, etc.

[0026] The pixel array section 100A, the pixel control unit 111, and the signal processing unit 112 may be provided on a single substrate. Alternatively, the pixel control unit 111, the signal processing unit 112, the control unit 113, and the processing unit 114 may be provided on a single semiconductor substrate, or they may be provided on multiple semiconductor substrates. The photodetector 1 may have a laminated structure formed by stacking multiple substrates. Some or all of the signal processing unit 112, the control unit 113, and the processing unit 114 may be integrally configured.

[0027] In the peripheral portion 100B, an optical black (OPB) region 100C for outputting a background signal is provided at the periphery of the pixel array portion 100A, as shown in Figure 3, for example. In the OPB region 100C, a photodiode (PD) is provided, for example, similar to the pixel array portion 100A.

[0028] [Circuit Configuration of Unit Pixel] Figure 4 shows an example of the circuit configuration of a unit pixel P of the light detection device 1 shown in Figure 1. A unit pixel P has, for example, one photoelectric conversion unit 12 and a readout circuit 31. The photoelectric conversion unit 12 is configured to receive light and generate a signal. The readout circuit 31 is configured to output a signal based on the photoelectrically converted charge. The readout circuit 31 can read out the pixel signal based on the charge photoelectrically converted by the photoelectric conversion unit 12.

[0029] The photoelectric conversion unit 12 is a so-called light receiving element, and is configured to be able to generate charges by photoelectric conversion. The photoelectric conversion unit 12 is, for example, a photodiode (PD), and converts incident light into charges. The photoelectric conversion unit 12 can perform photoelectric conversion and generate charges corresponding to the amount of received light.

[0030] As an example, the readout circuit 31 includes a transfer transistor TRG, a floating diffusion FD, an amplification transistor AMP, a selection transistor SEL, and a reset transistor RST. The transfer transistor TRG, the amplification transistor AMP, the selection transistor SEL, and the reset transistor RST are each MOS transistors (MOSFETs) having gate, source, and drain terminals.

[0031] For example, the transfer transistor TRG, the amplification transistor AMP, the selection transistor SEL, and the reset transistor RST are each constituted by NMOS transistors. Note that each transistor constituting the readout circuit 31 may be constituted by PMOS transistors.

[0032] The transfer transistor TRG is configured to be able to transfer the charges photoelectrically converted by the photoelectric conversion unit 12 to the floating diffusion FD. The transfer transistor TRG is controlled by a signal STRG, and electrically connects or disconnects the photoelectric conversion unit 12 and the floating diffusion FD. The transfer transistor TRG can transfer the charges photoelectrically converted and accumulated by the photoelectric conversion unit 12 to the floating diffusion FD.

[0033] The floating diffusion FD is an accumulation unit, and is configured to be able to accumulate the transferred charges. The floating diffusion FD can accumulate the charges photoelectrically converted by the photoelectric conversion unit 12. The floating diffusion FD can also be said to be a holding unit that can hold the transferred charges. The floating diffusion FD accumulates the transferred charges and converts them into a voltage corresponding to the capacitance of the floating diffusion FD.

[0034] The amplification transistor AMP is configured to generate and output a signal based on the charge accumulated in the floating diffusion FD. The amplification transistor AMP can generate and output a signal based on the charge converted by the photoelectric conversion unit 12.

[0035] The gate of the amplification transistor AMP is electrically connected to the floating diffusion FD, and the voltage converted by the floating diffusion FD is input. The drain of the amplification transistor AMP is connected to, for example, a power supply line to which the power supply voltage VDD is supplied.

[0036] The source of the amplification transistor AMP is connected to the signal line VSL via the selection transistor SEL. The amplification transistor AMP is configured to generate a signal based on the charge accumulated in the floating diffusion FD, that is, a signal based on the voltage of the floating diffusion FD, and output it to the signal line VSL.

[0037] The selection transistor SEL is configured to be able to control the output of the pixel signal. The selection transistor SEL is, for example, electrically connected in series with the amplification transistor AMP. The selection transistor SEL is controlled by the signal SSEL and is configured to be able to output the signal from the amplification transistor AMP to the signal line VSL. The selection transistor SEL can control the output timing of the pixel signal.

[0038] The selection transistor SEL is configured to be able to output a signal based on the charge converted by the photoelectric conversion unit 12. The selection transistor SEL can output the pixel signal of the unit pixel P to the signal line VSL. Note that the selection transistor SEL may be electrically connected in series between the power supply line to which the power supply voltage VDD is applied and the amplification transistor AMP. Also, the selection transistor SEL may be omitted as appropriate.

[0039] The reset transistor RST is configured to be able to reset the voltage of the floating diffusion FD. The reset transistor RST is, for example, electrically connected to the power supply line to which the power supply voltage VDD is applied and is configured to reset the charge of the unit pixel P.

[0040] The reset 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. The reset transistor RST can, for example, electrically connect the power line and the floating diffusion FD and discharge the charge accumulated in the floating diffusion FD. The reset transistor RST can also discharge the charge accumulated in the photoelectric conversion unit 12 via the transfer transistor TRG.

[0041] The pixel control unit 111 of the light detection device 1 supplies control signals to the gates of each unit pixel P, such as the transfer transistor TRG, the selection transistor SEL, and the reset transistor RST, via the control line Lread, to turn the transistors on (conducting) or off (non-conducting).

[0042] The multiple control lines Lread for each pixel row of the light detection device 1 include, as an example, wiring that transmits the signal STRG which controls the transfer transistor TRG, wiring that transmits the signal SSEL which controls the selection transistor SEL, and wiring that transmits the signal SRST which controls the reset transistor RST.

[0043] The readout circuit 31 may be configured to allow changing the conversion efficiency (gain) when converting charge to voltage. For example, the readout circuit 31 may have a switching transistor used to set the conversion efficiency. As an example, the switching transistor is electrically connected between the floating diffusion FD and the reset transistor RST.

[0044] In the readout circuit 31, when the switching transistor is turned on, the capacitance added to the floating diffusion FD of the unit pixel P increases, and the conversion efficiency is switched. The switching transistor can change the conversion efficiency by switching the capacitance connected to the gate of the amplification transistor AMP.

[0045] The transfer transistor TRG, selection transistor SEL, reset transistor RST, and switching transistors are controlled on and off by the pixel control unit 111. The pixel control unit 111 controls the readout circuit 31 of each unit pixel P to output a pixel signal from each unit pixel P to the signal line VSL. The pixel control unit 111 can control the reading of the pixel signal from each unit pixel P to the signal line VSL.

[0046] [Configuration of the Photodetector] As described above, the photodetector 1 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 20 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. As described above, the photodetector 1 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 20, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 20 includes a light-guiding section 27 which is composed of, for example, a plurality of structures 27A which are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The light detection device 1 has a spacer layer 24 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 20. The spacer layer 24 is constructed by stacking an organic layer 24A and an inorganic layer 24B in order from the semiconductor substrate 11 side. As shown in Figures 1 and 3, the spacer layer 24 is provided with a separation groove 25 that surrounds the pixel array section 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom of the separation groove 25, and the separation groove 25 is embedded by, for example, a medium 27B.

[0047] Here, the semiconductor substrate 11 corresponds to a specific example of a "semiconductor substrate" as one embodiment of the present disclosure. The light guide portion 27 corresponds to a specific example of a "light guide portion" as one embodiment of the present disclosure. The plurality of structures 27A corresponds to a specific example of a "multiple structures" as one embodiment of the present disclosure, and the medium 27B corresponds to a specific example of a "medium" and "protective film" as one embodiment of the present disclosure. The spacer layer 24 corresponds to a specific example of a "spacer layer" as one embodiment of the present disclosure. The organic layer 24A corresponds to a specific example of an "organic layer" as one embodiment of the present disclosure, and the inorganic layer 24B corresponds to a specific example of an "inorganic layer" as one embodiment of the present disclosure. The separation groove 25 corresponds to a specific example of a "separation groove" as one embodiment of the present disclosure.

[0048] The light-receiving unit 10 includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0049] The semiconductor substrate 11 is made of, for example, a silicon substrate (Si). The semiconductor substrate 11 may also be an SOI (Silicon On Insulator) substrate, a SiGe (Silicon Germanium) substrate, a SiC (Silicon Carbide) substrate, etc. The semiconductor substrate 11 may be made of a compound semiconductor material of group III-V, or it may be formed using other semiconductor materials. The first surface 11S1 of the semiconductor substrate 11 is the light-receiving surface (light incident surface). The second surface 11S2 of the semiconductor substrate 11 is the element formation surface on which elements such as transistors are formed. A gate electrode, a gate insulating film, etc., are provided on the second surface 11S2 of the semiconductor substrate 11.

[0050] The photoelectric conversion unit 12 is, for example, a Positive Intrinsic Negative (PIN) type photodiode (PD) and has a pn junction in a predetermined region of the semiconductor substrate 11. The photoelectric conversion unit 12 is formed by embedding one unit for each unit pixel P, for example.

[0051] The pixel isolation part 13 is provided between adjacent unit pixels P. In other words, the pixel isolation part 13 is provided so as to surround the unit pixel P, and is provided in a grid pattern across the pixel array part 100A and the OPB region 100C in its peripheral part. The pixel isolation part 13 electrically and optically separates adjacent unit pixels P, and for example, extends from the first surface 11S1 side of the semiconductor substrate 11 toward the second surface 11S2 side.

[0052] The pixel isolation part 13 can be formed, for example, by diffusing p-type impurities. In addition, the pixel isolation part 13 may have, for example, a Shallow Trench Isolation (STI) structure or a Full Trench Isolation (FTI) structure in which an insulating film is embedded by forming an opening from the first surface 11S1 side in the semiconductor substrate 11. Further, voids may be formed in the STI structure and the FTI structure.

[0053] On the first surface 11S1 of the semiconductor substrate 11, a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11 is provided. The dielectric layer 14 may be, for example, a film having positive fixed charges or a film having negative fixed charges.

[0054] Examples of the constituent material of the dielectric layer 14 include a semiconductor material or a conductive material having a bandgap wider than that of the semiconductor substrate 11. Specifically, for example, hafnium oxide (HfO ｘ ), aluminum oxide (AlO ｘ ), zirconium oxide (ZrO ｘ ), tantalum oxide (TaO ｘ ), titanium oxide (TiO ｘ ), lanthanum oxide (LaO ｘ ), praseodymium oxide (PrO ｘ ), cerium oxide (CeO ｘ ), neodymium oxide (NdO ｘ ), promethium oxide (PmO ｘ ), samarium oxide (SmO ｘ ), europium oxide (EuO ｘ ), gadolinium oxide (GdO ｘ ), terbium oxide (TbOｘ ), dysprosium oxide (DyO ｘ ), holmium oxide (HoO ｘ ), thulium oxide (TmO ｘ ), ytterbium oxide (YbO ｘ ), lutetium oxide (LuO ｘ ), yttrium oxide (YO ｘ ), hafnium nitride (HfN ｘ ), aluminum nitride (AlN ｘ ), hafnium oxynitride (HfO ｘ N ｙ ) and aluminum oxynitride (AlO ｘ N ｙ Examples include the following. The dielectric layer 14 may be a single layer or a multilayer film made of different materials.

[0055] The optical layer 20 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 24, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0056] The light-shielding film 21 is provided at the boundary between adjacent unit pixels P in the pixel array portion 100A and is a frame having an opening for each unit pixel P. The light-shielding film 21 is also provided in the OPB region 100C, and in the OPB region 100C, for example, it is formed to cover the entire surface of the OPB region 100C.

[0057] The light-shielding film 21 is intended to prevent light incident at an oblique angle from the light incident side S1 from leaking into adjacent unit pixels P in the pixel array section 100A, and to shield light incident on the photoelectric conversion section 12 in the OPB region 100C. The light-shielding film 21 can be formed using, for example, tungsten (W), silver (Ag), copper (Cu), titanium (Ti), aluminum (Al), or alloys thereof.

[0058] The partition wall 22 is patterned in the same way as the light-shielding film 21 and is laminated on the light-shielding film 21. In other words, the partition wall 22 is provided at the boundary between adjacent unit pixels P in the pixel array portion 100A, and is provided as a frame having an opening for each unit pixel P, and in the OPB region 100C, for example, it is formed to cover the entire surface of the OPB region 100C.

[0059] The partition wall 22 is designed to prevent light incident at an oblique angle from the light incident side S1 from leaking into adjacent unit pixels P. The partition wall 22 is constructed, for example, using a material with a lower refractive index than the color filter 23.

[0060] The partition wall 22 may also serve to shield the unit pixel P that determines the optical black level. Furthermore, the partition wall 22 may also serve to shield the peripheral circuitry provided in the peripheral area 100B from light. In this case, the partition wall 22 can be formed using, for example, a light-shielding material. Examples of such materials include tungsten (W), silver (Ag), copper (Cu), titanium (Ti), aluminum (Al), or alloys thereof. Other examples include metal compounds such as TiN. When the partition wall 22 is formed using the above-mentioned light-shielding material, the light-shielding film 21 can be omitted. The partition wall 22 may be configured as, for example, a single-layer film or a multilayer film. In the case of a multilayer film, for example, a layer made of Ti, tantalum (Ta), W, cobalt (Co), or molybdenum (Mo), or alloys, nitrides, oxides, or carbides thereof may be provided as an underlayer.

[0061] The color filters 23 selectively transmit light of a predetermined wavelength, and for example, include a red filter 23R that selectively transmits red light (R), a green filter 23G that selectively transmits green light (G), and a blue filter 23B that selectively transmits blue light (B). Each of the color filters 23R, 23G, and 23B is formed by filling the light-shielding film 21 and the opening 21H of the partition wall 22 with a resin material in which a desired pigment or dye is dispersed.

[0062] Each of the color filters 23R, 23G, and 23B is arranged such that, for example, for four unit pixels P arranged in a 2x2 grid, two green filters 23G are placed diagonally, and one red filter 23R and one blue filter 23B are placed diagonally opposite each other. In the unit pixels P provided with each of the color filters 23R, 23G, and 23B, for example, the corresponding color light is selectively photoelectrically converted in the respective photoelectric conversion unit 12.

[0063] Specifically, in the pixel array section 100A, unit pixels P (red pixel Pr) that selectively receive and convert red light (R) into photoelectric energy, unit pixels P (green pixel Pg) that selectively receive and convert green light (G) into photoelectric energy, and unit pixels P (blue pixel Pb) that selectively receive and convert blue light (B) into photoelectric energy are arranged in a Bayer pattern. The red pixel Pr, green pixel Pg, and blue pixel Pb each generate pixel signals for the red light (R) component, the green light (G) component, and the blue light (B) component, respectively. As a result, the light detection device 1 can obtain RGB pixel signals.

[0064] In addition to the red filter 23R, green filter 23G, and blue filter 23B, the color filter 23 may also include complementary color filters that selectively transmit cyan (C), magenta (M), and yellow (Y), respectively. Furthermore, the color filter 23 may also include a filter corresponding to white (W), that is, a filter that transmits light across the entire wavelength range of light incident on the light detection device 1. In addition, the color filter 23 may also include a filter that selectively transmits infrared light.

[0065] The film thickness of the color filter 23 may be different for each color, taking into consideration the color reproducibility and sensor sensitivity based on its spectral distribution.

[0066] In the OPB region 10C, as described above, the light-shielding film 21 and the partition wall 22 are formed to cover the entire surface of the OPB region 100C, and a color filter 23 is provided on the partition wall 22. Specifically, as shown in Figure 1, for example, a red filter 23R and a green filter 23G are arranged alternately in a checkerboard pattern on the partition wall 22, for example, in the row and column directions, and a blue filter 23B is provided to cover the red filter 23R and the green filter 23G.

[0067] The spacer layer 24 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 24 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0068] The spacer layer 24 has a structure in which an organic layer 24A formed using an organic material and an inorganic layer 24B formed using an inorganic material are stacked in this order from the light-receiving section 10 side. The inorganic layer 24B is for forming a flat surface while filling in the step in the organic layer 24A that occurs when covering the light-shielding film 21, partition wall 22, and color filter 23 or their stacked films provided on the light-receiving section 10. Examples of constituent materials for the organic layer 24A include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 24B include silicon oxide (SiO), silicon nitride (SiN), and aluminum oxide (AlO).

[0069] As described above, the separation groove 25 separates the spacer layer 24 and is provided so as to surround the pixel array portion 100A, as shown in Figures 1 and 3. The separation groove 25 penetrates the spacer layer 24 from the light incident side S1 and also penetrates the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom. The width of the separation groove 25 is preferably, for example, 10 nm or more. The separation groove 25 may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0070] The separation groove 25 is covered on its sides and bottom by a protective film with a thickness of, for example, 0.01 μm or more. Specifically, as shown in Figure 1, it is embedded by a medium 27B that constitutes the light guide portion 27. More specifically, the separation groove 25 is covered on its sides and bottom by an anti-reflective film 26 provided between the spacer layer 24 and the light guide portion 27, with the medium 27B embedded between the anti-reflective film 26. The medium 27B embedded in the separation groove 25 may have seams formed during film formation, as shown by the dotted line in Figure 1, or it may have voids formed inside. By embedding the separation groove 25 in this way, for example by the medium 27B, the intrusion of moisture into the organic layer 24A is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B is prevented.

[0071] In Figure 3, a continuous separation groove 25 is shown surrounding the pixel array section 100A, but the design is not limited to this. The separation groove 25 may, for example, be formed intermittently around the pixel array section 100A.

[0072] The anti-reflective coating 26 is intended to prevent surface reflection at the interface between the spacer layer 24 and the light guide portion 27. The anti-reflective coating 26 corresponds to a specific example of the "first anti-reflective coating" as one embodiment of the present disclosure, and covers the surface of the spacer layer 24 and extends to the side and bottom surfaces of the separation groove 25 as described above.

[0073] The anti-reflective coating 26 is composed of, for example, any of the following: silicon oxide (SiO), silicon nitride (SiN), silicon oxide nitride (SiON), silicon carbide (SiC), oxygen-doped silicon carbide (SiOC), nitrogen-doped silicon carbide (SiNC), aluminum oxide (AlO), hafnium oxide (HfO), tantalum oxide (TaO), and indium oxide (InO).

[0074] The light guide section 27 is configured as a light guide element capable of guiding light by, for example, providing a phase delay to the incident light. The light guide section 27 is a light guide element utilizing metamaterial (metasurface) technology. The light guide section 27 can also be called a metasurface layer (or metamaterial layer). In the light detection device 1, for example, as shown in Figure 1, the light guide section 27 is provided across the pixel array section 100A and the peripheral section 100B.

[0075] The light guide unit 27 has a plurality of structures 27A and a medium 27B provided around the plurality of structures 27A. The light guide unit 27 uses the plurality of nanostructures 27A to propagate light to the photoelectric conversion unit 12. Light from the object to be measured is incident on the light guide unit 27. Light that has passed through an optical system such as an imaging lens is incident on the plurality of structures 27A. The plurality of structures 27A have a size of less than or equal to a predetermined wavelength of the incident light, for example, a size of less than or equal to the wavelength range of visible light. The plurality of structures 27A may also have a size of less than or equal to the wavelength range of infrared light.

[0076] Each of the multiple structures 27A is, for example, a columnar (pillar-shaped) structure and can be called a nanopillar. The multiple structures 27A can be called a metasurface element. As an example, the multiple structures 27A have a cylindrical shape. The multiple structures 27A are arranged so as to be aligned with each other in the X-axis direction or the Y-axis direction with the medium 27B in between.

[0077] The shapes of the multiple structures 27A can be changed as appropriate, and each may be circular or rectangular in plan view. The shapes of the multiple structures 27A may also be elliptical, polygonal, cross-shaped, or other shapes.

[0078] The multiple structures 27A are also referred to as metaatoms, nanoatoms, nanoposts, metasurface structures, microstructures, etc.

[0079] The medium 27B is provided to fill the periphery of the multiple structures 27A. The multiple structures 27A are provided within the medium 27B, and it can also be said that they are arranged by replacing a part of the medium 27B. The medium 27B can also be called a medium layer or a protective layer (protective member).

[0080] In the light guide section 27, multiple structures 27A are arranged at intervals less than or equal to a predetermined wavelength of incident light. As an example, multiple structures 27A are provided in the X-axis and Y-axis directions at intervals less than or equal to the wavelength range of visible light. In the case of a unit pixel P, multiple structures 27A may be arranged at intervals less than or equal to the wavelength range of infrared light.

[0081] The multiple structures 27A have refractive indices different from those of the surrounding medium 27B. For example, the multiple structures 27A have refractive indices higher than those of the medium 27B.

[0082] Examples of constituent materials for the multiple structures 27A include titanium oxide (TiO), silicon, polysilicon (Poly-Si), amorphous silicon (a-Si), germanium (Ge), and the like.

[0083] The multiple structures 27A may be formed using elements such as titanium (Ti), hafnium (Hf), zirconium (Zr), aluminum (Al), tantalum (Ta), indium (In), and niobium (Nb), or their oxides, nitrides, oxynitrides, or composites thereof. The multiple structures 27A may also be formed by including other metal compounds (metal oxides, metal nitrides, etc.).

[0084] Multiple structures 27A may be formed using GaP, GaN, GaAs, SiC, etc. Multiple structures 27A may be formed using silicon oxide (SiO), silicon nitride (SiN), silicon oxide nitride (SiON), silicon carbide (SiC), oxygen-doped silicon carbide (SiOC), or other silicon compounds. Multiple structures 27A may be composed of different materials from each other.

[0085] The medium 27B is composed of, for example, an inorganic material such as an oxide, nitride, or oxynitride. The medium 27B may be formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxide nitride (SiON), silicon carbide (SiC), oxygen-doped silicon carbide (SiOC), or other silicon compounds. The medium 27B may also be formed using TEOS.

[0086] The medium 27B may be formed using a siloxane resin, a styrene resin, an acrylic resin, or the like. The medium 27B may also be composed of a material in which fluorine is contained in any of these resins. The medium 27B may also be formed using a material in which beads (fillers) having a higher (or lower) refractive index than the resin are embedded in any of these resins.

[0087] The materials of the multiple structures 27A and the medium 27B can be selected according to the refractive index difference with the surrounding medium, the wavelength range of the incident light to be measured, etc. Note that some of the multiple structures 27A and the medium 27B may be made of air. For example, the multiple structures 27A may be made including air (voids).

[0088] The light guide 27 can control the wavefront of light by, for example, generating a phase delay in the incident light due to the difference in refractive index between the multiple structures 27A and the surrounding medium. The light guide 27 can adjust the propagation direction of light by, for example, providing a phase delay to the incident light using the multiple structures 27A and the medium 27B.

[0089] The materials of the multiple structures 27A and the medium 27B (optical constants of each material), the size of the multiple structures 27A (width (diameter), height, etc.), the pitch (arrangement interval), etc. are determined so that light in a desired wavelength range from the light incident from the object to be measured travels in a desired direction. For example, the materials (refractive index), dimensions, and pitch of the multiple structures 27A, and the materials (refractive index) of the medium 27B, etc., may be set.

[0090] Furthermore, in the light detection device 1, the material, size, and number of arrangements of the multiple structures 27A of each unit pixel P are determined so that light of a specific wavelength band to be detected proceeds to the photoelectric conversion unit 12 of the desired unit pixel P. For example, the multiple structures 27A provided in the red pixel Pr, green pixel Pg, and blue pixel Pb may be formed to have different sizes (e.g., width, height) and arrangement positions. As an example, the light guide portion 27 may be formed with a thickness of, for example, 0.01 μm to 2 μm.

[0091] The light guide unit 27 may be configured, for example, as a spectrometer (spectroscopic element) capable of spectrally separating incident light. The optical layer 20 (or light guide unit 27) can also be called a splitter (color splitter). The optical layer 20 can also be called a color splitter layer or a wavelength separation layer. The optical layer 20 (or light guide unit 27) can also be called an optical element configured to redirect light.

[0092] The anti-reflective coating 28 is for preventing surface reflection of the light guide portion 27. Similar to the anti-reflective coating 26, the anti-reflective coating 28 is composed of, for example, one of the following: silicon oxide (SiO), silicon nitride (SiN), silicon oxide nitride (SiON), silicon carbide (SiC), oxygen-doped silicon carbide (SiOC), nitrogen-doped silicon carbide (SiNC), aluminum oxide (AlO), hafnium oxide (HfO), tantalum oxide (TaO), and indium oxide (InO).

[0093] The multilayer wiring layer 30 is provided by laminating it on the semiconductor substrate 11. The multilayer wiring layer 30 includes, for example, a conductive film and an insulating film, and has a plurality of wirings and vias. The multilayer wiring layer 30 has a configuration in which a plurality of wirings are laminated with an insulating film acting as an interlayer insulating film. The multilayer wiring layer 30 includes, for example, two or three or more layers of wiring.

[0094] The wiring of the multilayer wiring layer 30 is formed using metallic materials such as aluminum (Al), copper (Cu), and tungsten (W). Alternatively, the wiring of the multilayer wiring layer 30 may be constructed using polysilicon (Poly-Si) or other conductive materials. The interlayer insulating film can be formed using, for example, silicon oxide (SiO), silicon nitride (SiN), or silicon oxynitride (SiON).

[0095] The semiconductor substrate 11 and the multilayer wiring layer 30 are provided with, for example, the above-described readout circuit 31 for each unit pixel P or for each of multiple unit pixels P. In addition to the above-described readout circuit 31, the multilayer wiring layer 30 may also be formed with, for example, a pixel control unit 111, a signal processing unit 112, a control unit 113, and a processing unit 114.

[0096] The peripheral portion 100B is provided with an opening H through which the light detection device 1 penetrates from the light incident side S1 to the multilayer wiring layer 30. An electrode 32 provided within the multilayer wiring layer 30 is exposed at the bottom surface of the opening H, and wiring connecting this electrode 32 to an external electrode or the like is provided in the opening H.

[0097] [Manufacturing Method for the Light Detection Device] Figures 5A to 5G show the manufacturing method for the light detection device 1 in order of steps.

[0098] First, as shown in Figure 5A, a light-shielding film 21, a partition wall 22, and a color filter 23 are formed sequentially on the first surface 11S1 of the semiconductor substrate 11.

[0099] Next, as shown in Figure 5B, an organic layer 24A and an inorganic layer 24B are sequentially deposited as a spacer layer 24 using, for example, chemical vapor deposition (CVD).

[0100] Next, as shown in Figure 5C, the surface of the inorganic layer 24B is planarized using, for example, chemical mechanical polishing (CMP).

[0101] Next, as shown in Figure 5D, for example, a resist film 41 is patterned on the spacer layer 24 using photolithography technology, and then, for example, a separation groove 25 is formed that penetrates the spacer layer 24 and the dielectric layer 14 and reaches the semiconductor substrate 11 using wet etching.

[0102] Next, as shown in Figure 5E, after removing the resist film 41, an anti-reflective film 26 is deposited on the spacer layer 24 and on the sides and bottom of the separation groove 25 using, for example, a sputtering method. Then, a medium 27B made of a low refractive index material (e.g., SiN / TEOS) is deposited. This fills the separation groove 25 with the medium 27B.

[0103] Next, as shown in Figure 5F, the surface of the medium 27B is planarized, for example, using the CMP method, so that the arithmetic mean roughness (Ra) is 0.5 or less.

[0104] Next, for example, the medium 27B is processed using photolithography to form an opening, and then a high refractive index material (e.g., TiO) is deposited using atomic layer deposition (ALD). ２ A ) is embedded in the opening, and for example, the high refractive index film deposited on the medium 27B is removed using the CMP method. As a result, a light guide section 27 is formed in which multiple structures 27A are embedded in the medium 27B, as shown in Figure 5G. Subsequently, as shown in Figure 5G, an anti-reflective film 28 is deposited on the light guide section 27 using, for example, the sputtering method. With the above steps, the light detection device 1 shown in Figure 1 is completed.

[0105] The manufacturing method described above is merely one example, and other manufacturing methods may be used.

[0106] [Function and Effects] In the photodetector 1 of this embodiment, a separation groove 25 is provided that penetrates a spacer layer 24, which is provided between a semiconductor substrate 11 having a photoelectric conversion unit 12 and a light guide unit 27, and which has an organic layer 24A and an inorganic layer 24B stacked in that order from the semiconductor substrate 11 side, for example, so as to surround the pixel array unit 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom surface of the separation groove 25, and the medium 27B constituting the light guide unit 27 is embedded inside so that a protective film extends to the side and bottom surfaces of the separation groove 25. This reduces the intrusion of moisture through the organic layer 24A and prevents displacement of the light guide unit 27 caused by the stacking of the organic layer 24A and the inorganic layer 24B. This will be explained below.

[0107] In recent years, a technology has attracted attention that uses nanopost structures to scatter light and spatially separate wavelengths, thereby increasing the effective light-gathering area for each color compared to a single pixel, as a countermeasure against the decrease in pixel sensitivity due to miniaturization. Nanopost structures have a high refractive index relative to the surrounding medium, and a phase difference corresponding to the wavelength is generated between the nanopost structure and the medium. Therefore, by optimizing the radius, length, and arrangement of the nanoposts, the visible wavelength band corresponding to each color pixel constituting the pixel unit can be distributed. This makes it possible to achieve higher sensitivity compared to full-color image sensors that acquire RGB color information using general color filters.

[0108] Figure 6 schematically shows an example of the cross-sectional configuration of a typical image sensor (photodetector 1100) in which a color filter is arranged between a semiconductor substrate having the photoelectric conversion unit described above and a layer containing the nanopost structure (hereinafter referred to as the metasurface layer). The photodetector 1100, like the photodetector 1 of this embodiment, has a light-receiving unit 1110 and an optical layer 1120 provided on the light incident side of the light-receiving unit 1110. The optical layer 1120 includes a light-guiding unit 1127 composed of a plurality of structures 1127A corresponding to the nanopost structure and a medium 1127B filling the spaces between adjacent structures 1127A, and further has a spacer layer 1124 between the light-receiving unit 1110 and the light-guiding unit 1127. The spacer layer 1124 generally has a laminated structure of a layer made of an organic material with excellent step coverage (organic layer 1124A) and a layer made of an inorganic material with excellent surface processability (inorganic layer 1124B).

[0109] Thus, in a light detection device 1100 in which a light guide portion 1127 is formed on a spacer layer 1124 in which an organic layer 1124A and an inorganic layer 1124B are stacked, a problem arises when reliability is increased: under load, the position of multiple structures 1127A formed in a predetermined pattern above each pixel shifts due to the difference in thermal expansion coefficients between the organic layer 1124A and the inorganic layer 1124B, resulting in a decrease in the reliability of the light focusing design.

[0110] In contrast, the aforementioned photodetector employs a means to physically prevent displacement of the multiple structures 1127A under reliability load by providing a sidewall protective film on the sidewall of the spacer layer.

[0111] Figure 7 schematically shows an example of the cross-sectional configuration of the aforementioned photodetector (photodetector 1200). The photodetector 1200, like the photodetector 1 of this embodiment, has a light-receiving section 1210 and an optical layer 1220 provided on the light-incident side of the light-receiving section 1210. The optical layer 1220 includes a metasurface layer (light guide section 1227) composed of a plurality of structures 1227A corresponding to microstructures and a medium 1227B corresponding to a transparent layer, and further has a spacer layer 1224 between the light-receiving section 1210 and the light guide section 1227. The spacer layer 1224 has a laminated structure of a layer made of organic material (organic layer 1224A) and a layer made of inorganic material (inorganic layer 1224B). In the photodetector 1200, as shown in Figure 7, a medium 1227B is formed on the side surface of the separation groove 1225 that separates the spacer layer 1224, for example, as a sidewall protective film, thereby physically preventing displacement of the multiple structures 1227A under reliability load.

[0112] However, in this configuration, the thickness of the sidewall protective film is determined by the thickness of the light guide portion 1227, and a medium 1227B, which is thinner than the light guide portion 1227, is formed on the side of the separation groove 1225 as a sidewall protective film. Therefore, the effect of physically preventing misalignment of the multiple structures 1227A is insufficient, and furthermore, misalignment that appears to be due to the heat load process when embedding the multiple structures 1227A into the medium 1227B was observed.

[0113] In contrast, in this embodiment, a spacer layer 24 provided between the semiconductor substrate 11 having the photoelectric conversion unit 12 and the light guide unit 27 is provided, for example, with a separation groove 25 that penetrates so as to surround the pixel array unit 100A in a plan view and exposes the semiconductor substrate 11 on its bottom surface, and a medium 27B is extended as a protective film on its side and bottom surfaces, so that, for example, the separation groove 25 is embedded by the medium 27B. As a result, compared to the above-mentioned photodetector 1200, the intrusion of moisture through the organic layer 24A is further reduced, and displacement of the light guide unit 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B is prevented.

[0114] As a result of the above, the reliability of the light detection device 1 in this embodiment can be improved.

[0115] Furthermore, in this embodiment, a separation groove 25 is provided that partially excavates the semiconductor substrate 11, so that the displacement of the light guide portion 27 can be physically prevented more firmly than in the above-mentioned photodetector 1200. Therefore, the photodetector 1 of this embodiment can improve optical characteristics.

[0116] Furthermore, in this embodiment, after the separation groove 25 is filled with the medium 27B, the surface of the medium 27B is flattened using, for example, the CMP method, and its film thickness is adjusted to a predetermined thickness. Therefore, the film thickness of the light guide section 27 and the film thickness of the protective film extending to the side and bottom surfaces of the separation groove 25 become independent parameters. Thus, the photodetector 1 of this embodiment can achieve both reliability and optical characteristics.

[0117] Next, the second to eighth embodiments and modifications 1 to 14 of this disclosure, as well as application examples and usage examples, will be described. In the following, components similar to those in the first embodiment described above will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0118] <2. Modification 1> Figure 8 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 1A) according to Modification 1 of the present disclosure. The photodetector 1A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the above embodiment, is, for example, a so-called back-illuminated photodetector.

[0119] In the first embodiment described above, an example was shown in which a single-layer light guide section 27 was provided, but the invention is not limited to this. Multiple light guide sections can be stacked, and the light detection device 1A in this modified example differs from the first embodiment in that two layers of light guide sections (light guide sections 27 and 29) are stacked.

[0120] Here, the light guide portion 27 corresponds to a specific example of the "first light guide portion" as one embodiment of the present disclosure, and the light guide portion 29 corresponds to a specific example of the "second light guide portion" as one embodiment of the present disclosure.

[0121] The light guide section 29, like the light guide section 27, is configured as a light guide element capable of guiding light by, for example, imparting a phase delay to the incident light. The light guide section 29 is a light guide element utilizing metamaterial (metasurface) technology. The light guide section 29 can also be called a metasurface layer (or metamaterial layer). In the light detection device 1A, the light guide section 29 is provided over the pixel array section 100A and the peripheral section 100B, similar to the light guide section 27 in the first embodiment described above.

[0122] Each light guide unit 29 has a plurality of structures 29A and a medium 29B provided around the plurality of structures 29A. The light guide unit 29 uses the plurality of nanostructures 29A to propagate light to the photoelectric conversion unit 12. Light from the object to be measured is incident on the light guide unit 29. Light that has passed through an optical system such as an imaging lens is incident on the plurality of structures 29A. The plurality of structures 29A have a size of less than or equal to a predetermined wavelength of the incident light, for example, a size of less than or equal to the wavelength range of visible light. The plurality of structures 29A may also have a size of less than or equal to the wavelength range of infrared light.

[0123] Each of the multiple structures 29A is, for example, a columnar (pillar-shaped) structure and can be called a nanopillar. The multiple structures 29A can be called a metasurface element. As an example, the multiple structures 29A have a cylindrical shape. The multiple structures 29A are arranged so as to be aligned with each other in the X-axis direction or the Y-axis direction with the medium 29B in between.

[0124] The shapes of the multiple structures 29A can be changed as appropriate, and each may be circular or rectangular in plan view. The shapes of the multiple structures 29A may also be elliptical, polygonal, cross-shaped, or other shapes.

[0125] The multiple structures 29A are also referred to as metaatoms, nanoatoms, nanoposts, metasurface structures, microstructures, etc.

[0126] The medium 29B is provided so as to fill the periphery of each of the multiple structures 29A. Each of the multiple structures 29A is provided within the medium 29B, and it can also be said that they are arranged by replacing a part of the medium 29B. The medium 29B can also be called a medium layer or a protective layer (protective member).

[0127] In the light guide section 29, multiple structures 29A are arranged at intervals less than or equal to a predetermined wavelength of incident light. As an example, multiple structures 29A are provided in the X-axis and Y-axis directions at intervals less than or equal to the wavelength range of visible light. In the case of a unit pixel P, multiple structures 29A may be arranged at intervals less than or equal to the wavelength range of infrared light.

[0128] Multiple structures 29A have refractive indices different from those of the surrounding medium 29B. For example, multiple structures 29A have refractive indices higher than those of the medium 29B.

[0129] Examples of constituent materials for the multiple structures 29A include titanium oxide (TiO), silicon, polysilicon (Poly-Si), amorphous silicon (a-Si), germanium (Ge), and the like.

[0130] The multiple structures 29A may be formed from elements such as titanium (Ti), hafnium (Hf), zirconium (Zr), aluminum (Al), tantalum (Ta), indium (In), and niobium (Nb), or from their oxides, nitrides, oxynitrides, or composites thereof. The multiple structures 29A may also be formed from other metal compounds (metal oxides, metal nitrides, etc.).

[0131] Multiple structures 29A may be formed using GaP, GaN, GaAs, SiC, etc. Multiple structures 29A may be formed using silicon oxide, silicon nitride, silicon oxide nitride, silicon carbide, silicon oxide carbide, or other silicon compounds. Multiple structures 29A may be composed of different materials from each other.

[0132] The medium 29B is composed of, for example, an inorganic material such as an oxide, nitride, or oxynitride. The medium 29B may also be formed using, for example, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon oxide carbide, or other silicon compounds. The medium 29B may also be composed of TEOS.

[0133] The medium 29B may be composed of a siloxane resin, a styrene resin, an acrylic resin, or the like. The medium 29B may also be composed of a material in which fluorine is contained in any of these resins. The medium 29B may also be formed using a material in which beads (fillers) having a higher (or lower) refractive index than the resin are embedded in any of these resins.

[0134] The materials of the multiple structures 29A and the medium 29B can be selected according to the refractive index difference with the surrounding medium, the wavelength range of the incident light to be measured, etc. Note that some of the multiple structures 29A and the medium 29B may be made of air. For example, the multiple structures 29A may be made including air (voids).

[0135] The light guides 27 and 29 are configured, for example, as light guide elements capable of guiding light by imparting a phase delay to the incident light. In the light detection device 1A, multiple structures 27A and 29A and media 27B and 29B are arranged to give a desired phase profile to the incident light. For example, the materials (optical constants of each material), the size (width (diameter), height, etc.), and pitch (arrangement interval) of the multiple structures 27A and 29A and media 27B and 29B are determined so that light in the wavelength band to be detected is focused onto the photoelectric conversion unit 12. For example, the materials (refractive index), dimensions, and pitch of the multiple structures 27A and 29A, and the materials (refractive index) of the media 27B and 29B may be set.

[0136] Between the light guide portion 27 and the light guide portion 29, and on the light guide portion 29, anti-reflective films 28A and 28B are provided, respectively. The anti-reflective film 28A corresponds to a specific example of the "second anti-reflective film" as one embodiment of the present disclosure. The anti-reflective films 28A and 28B are composed of, for example, single-layer films made of silicon oxide, silicon nitride, and silicon oxynitride, or laminated films made of two or more of these, similar to the anti-reflective films 26 and 28 described above. The anti-reflective films 28A and 28B may be omitted as appropriate.

[0137] As described above, in this modified photodetector 1A, a multi-stage light guide section 27, 29 is provided on the first surface 11S1 side of the semiconductor substrate 11. In the photodetector 1A, the separation groove 25 is embedded by the medium 27B constituting the first stage light guide section 27, similar to the first embodiment, and the second stage light guide section 29 is provided with a substantially uniform film thickness extending over the pixel array section 100A and the peripheral section 100B. Even with this configuration, the photodetector 1A in this modified example can obtain the same effects as the first embodiment.

[0138] <3. Second Embodiment> Figure 9 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 2) according to the second embodiment of the present disclosure. The photodetector 2 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0139] [Configuration of the Photodetector] As described above, the photodetector 2 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 50 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the first embodiment described above, the photodetector 2 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 50, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 50 includes a light-guiding section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The light detection device 2 has a spacer layer 54 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 50. The spacer layer 54 is constructed by stacking an organic layer 54A and inorganic layers 54B and 54C in order from the semiconductor substrate 11 side. In this embodiment, the organic layer 54A and the inorganic layer 54B of the spacer layer 54 are provided with separation grooves 55 so as to surround the pixel array section 100A in a plan view, similar to the first embodiment described above. The semiconductor substrate 11 is exposed at the bottom of the separation grooves 55, and the separation grooves 55 are embedded by the inorganic layer 54C.

[0140] Here, the spacer layer 54 corresponds to a specific example of a "spacer layer" as one embodiment of the present disclosure. The inorganic layer 54C corresponds to a specific example of a "protective film" as one embodiment of the present disclosure. The separation groove 55 corresponds to a specific example of a "separation groove" as one embodiment of the present disclosure.

[0141] The light-receiving unit 10, similar to the first embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0142] The optical layer 50 has the same configuration as the optical layer 20 of the first embodiment, except for the spacer layer 54. That is, the optical layer 50 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0143] The spacer layer 54 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 54 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0144] The spacer layer 54 has a structure in which an organic layer 54A formed using an organic material and inorganic layers 54B and 54C formed using inorganic materials are stacked in this order from the light-receiving section 10 side. The inorganic layer 54B is for protecting the surface of the light-shielding film 21, partition wall 22, and color filter 23 provided on the light-receiving section 10, or the organic layer 54A covering these laminated films, and may be omitted. The inorganic layer 54C is for filling in the steps of the organic layer 54A caused by covering the light-shielding film 21, partition wall 22, and color filter 23, or these laminated films, and forming a flat surface. In this embodiment, the inorganic layer 54C also serves as a protective film that fills the separation groove 55, as described above.

[0145] Examples of constituent materials for the organic layer 54A include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 54B include silicon oxide (SiO). Examples of constituent materials for the inorganic layer 54C include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO). The thicknesses of the organic layer 54A and the inorganic layer 54B are not particularly limited, but the thickness of the inorganic layer 54C that fills the separation groove 55 is preferably, for example, 500 nm or more and 5000 nm or less.

[0146] The separation groove 55 separates the spacer layer 54, similar to the separation groove 25 in the first embodiment described above, and is provided so as to surround the pixel array portion 100A. The separation groove 55 penetrates the organic layer 54A and the inorganic layer 54B of the spacer layer 54, and further penetrates the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom surface. The width of the separation groove 55 is preferably, for example, 100 nm or more and 15000 nm or less. The separation groove 55 may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0147] As shown in Figure 9, the separation groove 55 is embedded by an inorganic layer 54C. In other words, the separation groove 55 is embedded by a protective film which is a single layer of the same material as the inorganic layer 54C. The inorganic layer 54C embedded in the separation groove 55 may have seams formed during its deposition, as shown by the dotted line in Figure 9, or it may have voids formed inside. By embedding the separation groove 55 in this way, for example by an inorganic layer 54C, the intrusion of moisture into the organic layer 54A is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 24B is prevented.

[0148] [Manufacturing Method for the Light Detection Device] Figures 10A to 10F show the manufacturing method for the light detection device 2 in order of steps.

[0149] First, as shown in Figure 10A, a light-shielding film 21, a partition wall 22, and a color filter 23 are formed sequentially on the first surface 11S1 of the semiconductor substrate 11.

[0150] Next, as shown in Figure 10B, an organic layer 54A and an inorganic layer 54B are sequentially deposited as a spacer layer 54 using, for example, the CVD method.

[0151] Next, as shown in Figure 10C, for example, a resist film 42 is patterned on the inorganic layer 54B using photolithography technology, and then, for example, a separation groove 55 is formed by wet etching that penetrates the inorganic layer 54B, the organic layer 54A, and the dielectric layer 14 and reaches the semiconductor substrate 11.

[0152] Next, as shown in Figure 10D, after removing the resist film 41, an inorganic layer 54C is formed using, for example, a CVD method. This fills the separation groove 55 with the inorganic layer 54C.

[0153] Next, as shown in Figure 10E, the surface of the inorganic layer 54C is planarized, for example, using the CMP method, so that the arithmetic mean roughness (Ra) is 0.5 or less.

[0154] Next, as shown in Figure 10F, the anti-reflective film 26, the light guide portion 27, and the anti-reflective film 28 are formed sequentially on the spacer layer 54 in the same manner as in the first embodiment described above. With this, the light detection device 2 shown in Figure 8 is completed.

[0155] The manufacturing method described above is merely one example, and other manufacturing methods may be used.

[0156] [Function and Effects] In the photodetector 2 of this embodiment, a separation groove 55 is provided in the organic layer 54A and the inorganic layer 54B of the spacer layer 54, which is provided between the semiconductor substrate 11 having the photoelectric conversion unit 12 and the light guide unit 27, and is constructed by stacking an organic layer 54A and inorganic layers 54B and 54C in that order from the semiconductor substrate 11 side, for example, penetrating so as to surround the pixel array unit 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom surface of the separation groove 55, and the inorganic layer 54C is embedded inside it. As a result, similar to the first embodiment described above, the intrusion of moisture through the organic layer 54A is reduced, and displacement of the light guide unit 27 caused by the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layers 54B and 54C is prevented.

[0157] As described above, the light detection device 2 of this embodiment can improve reliability in the same way as the light detection device 1 of the first embodiment.

[0158] Furthermore, in the photodetector 2 of this embodiment, the separation groove 55 is filled with only the inorganic layer 54C. Compared to the case where the separation groove 25 is filled with multiple layers (for example, an anti-reflective film 26 and a medium 27B), as in the photodetector 1 of the first embodiment described above, concerns about reflection at the interface and film peeling are reduced.

[0159] <4. Modifications> (4-1. Modification 2) Figure 11 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 2A) according to Modification 2 of the present disclosure. The photodetector 2A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0160] In the second embodiment described above, an example was shown in which a single-layer light guide section 27 was provided, but the invention is not limited to this. Multiple light guide sections can be stacked, and the light detection device 2A of this modified example differs from the second embodiment in that, similar to the first modified example, two layers of light guide sections (light guide sections 27 and 29) are stacked.

[0161] As described above, in the modified photodetector 2A, a multi-stage light guide section 27, 29 is provided on the first surface 11S1 side of the semiconductor substrate 11. In the photodetector 2A, the separation groove 55 is embedded by an inorganic layer 54C, similar to the second embodiment, and the light guide sections 27, 29 are provided above the spacer layer 54 with a substantially uniform film thickness extending over the pixel array section 100A and the peripheral section 100B. Even with this configuration, the modified photodetector 2A can obtain the same effects as the first and second embodiments.

[0162] (4-2. Modification 3) Figure 12 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 2B) according to Modification 3 of the present disclosure. The photodetector 2B is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0163] In this modified example, the light detection device 2B has an opening 55H inside the separation groove 55 that penetrates the light guides 27 and 29, the anti-reflective films 26 and 28A, and the spacer layer 54, with a light-shielding film 61 embedded inside. The opening 55H contains the light-shielding film 61 along with the anti-reflective film 28B and the medium 29B that constitutes the light guide 29. Except for this point, the light detection device 2B has substantially the same configuration as the light detection device 2 of the second embodiment described above.

[0164] The light-shielding film 61 is intended to prevent light from entering from the peripheral portion 100B. As described above, the light-shielding film 61 has an opening 55H embedded in it that penetrates the light guide portions 27, 29, the anti-reflective films 26, 28A and the spacer layer 54, and further extends onto the anti-reflective film 28B in the peripheral portion 100B. This prevents surface reflection in the peripheral portion 100B.

[0165] The light-shielding film 61 is formed, for example, from a black color filter or a light-shielding metal film such as tungsten (W) or copper (Cu). Examples of constituent materials for the black color filter include titanium oxide filler dispersion resin, carbon black dye dispersion resin, and organic pigment dispersion resin. In addition, the light-shielding film 61 may be formed using, for example, a black resist.

[0166] In this modified light detection device 2B, an opening 55H is provided inside the separation groove 55, penetrating the light guide sections 27, 29, the anti-reflective films 26, 28A, and the spacer layer 54, and a light-shielding film 61 is embedded inside it. This makes it possible to further improve the optical characteristics compared to the second embodiment described above.

[0167] <5. Third Embodiment> Figure 13 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 3) according to the third embodiment of the present disclosure. The photodetector 3 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0168] [Configuration of the Light Detection Device] As described above, the light detection device 3 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light receiving section 10, an optical layer 70 provided on the light incident side S1 of the light receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light receiving section 10 are stacked. Similar to the first embodiment described above, the light detection device 3 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light receiving section 10, the optical layer 70, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 70 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 73, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28. In this embodiment, the light-shielding film 21 and the partition wall 22 are stacked on top of each other, and the color filter 73, which includes a red filter 73R, a green filter 73G, and a blue filter 73B that fill the openings of the light-shielding film 21 and the partition wall 22, is provided over the pixel array portion 100A and the peripheral portion 100B. In the peripheral portion 100B, for example, a separation groove 75 is provided that separates the organic layer 54A of the spacer layer 54, which is stacked in order from the semiconductor substrate 11 side, as well as the light-shielding film 21, the partition wall 22, and the color filter 73 that extend to the peripheral portion 100B, so as to surround the pixel array portion 100A in a plan view. The separation groove 75 is filled with the inorganic layer 54B.

[0169] Here, the color filter 73 corresponds to a specific example of the "color filter" as one embodiment of the present disclosure. The separation groove 75 corresponds to a specific example of the "separation groove" as one embodiment of the present disclosure.

[0170] The light-receiving unit 10, similar to the first embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0171] As described above, the optical layer 70 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 73, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0172] The color filter 73 selectively transmits light of a predetermined wavelength, and for example, it includes a red filter 73R that selectively transmits red light (R), a green filter 73G that selectively transmits green light (G), and a blue filter 73B that selectively transmits blue light (B). Each of the color filters 73R, 73G, and 73B is formed by filling the light-shielding film 21 and the opening 21H of the partition wall 22 with a resin material in which a desired pigment or dye is dispersed.

[0173] Each of the color filters 73R, 73G, and 73B is arranged such that, for example, for four unit pixels P arranged in a 2x2 grid, two green filters 73G are placed diagonally, and one red filter 73R and one blue filter 73B are placed diagonally opposite each other. In the unit pixels P provided with each of the color filters 73R, 73G, and 73B, for example, the corresponding color light is selectively photoelectrically converted in the respective photoelectric conversion unit 12.

[0174] Specifically, in the pixel array section 100A, unit pixels P (red pixel Pr) that selectively receive and convert red light (R) into photoelectric energy, unit pixels P (green pixel Pg) that selectively receive and convert green light (G) into photoelectric energy, and unit pixels P (blue pixel Pb) that selectively receive and convert blue light (B) into photoelectric energy are arranged in a Bayer pattern. The red pixel Pr, green pixel Pg, and blue pixel Pb each generate pixel signals for the red light (R) component, the green light (G) component, and the blue light (B) component, respectively. As a result, the light detection device 3 can obtain RGB pixel signals.

[0175] Furthermore, in this embodiment, the color filter 73 is also provided in the peripheral portion 100B in the same way as in the pixel array portion 100A. However, in the OPB region 10C, the light-shielding film 21 and the partition wall 72 are formed to cover the entire surface of the OPB region 100C, and the color filter 73 is provided on the partition wall 72.

[0176] The spacer layer 54 is provided between the light-receiving section 10 and the light-guiding section 27, and is formed to extend over the pixel array section 100A and the peripheral section 100B so as to be laminated on the light-shielding film 21, partition wall 22, and color filter 23, which are provided over the pixel array section 100A and the peripheral section 100B. The spacer layer 54 has a structure in which an organic layer 54A made of organic material and an inorganic layer 54B made of inorganic material are laminated in this order from the light-receiving section 10 side. In this embodiment, the inorganic layer 54B also serves as a protective film that fills the separation groove 75.

[0177] The separation groove 75 separates the spacer layer 54, similar to the separation groove 25 in the first embodiment described above, and is provided so as to surround the pixel array portion 100A. The separation groove 75 penetrates the organic layer 54A of the spacer layer 54, and further penetrates the light-shielding film 21, the partition wall 22, the color filter 23, and the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom surface. The width of the separation groove 75 is preferably, for example, 100 nm or more and 15000 nm or less. The separation groove 75 may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0178] As shown in Figure 13, the separation groove 75 is embedded with an inorganic layer 54B. By embedding the separation groove 75 with, for example, an inorganic layer 54B, the intrusion of moisture into the organic layer 54A is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 54B is prevented.

[0179] [Effects] In the light detection device 3 of this embodiment, a color filter 73, including a light-shielding film 21 and partition walls 22 stacked on top of each other, and a red filter 73R, a green filter 73G, and a blue filter 73B filled in their openings, is provided over the pixel array section 100A and the peripheral section 100B. As a result, compared to the second embodiment described above, for example, the number of steps with different elevations on the surface of the inorganic layer 54B constituting the spacer layer 54 before flattening using, for example, the CMP method is reduced. In other words, the amount of polishing by CMP is reduced, so that variations in the surface height of the spacer layer 54 can be suppressed.

[0180] As described above, the photodetector 3 of this embodiment makes it easier to flatten the surface of the inorganic layer 54C, for example, so that the arithmetic mean roughness (Ra) is 0.5 or less.

[0181] <6. Modifications> (6-1. Modification 4) Figure 14 schematically shows an example of the cross-sectional configuration of a photodetector (photodetector 3A) according to Modification 4 of the present disclosure. Figure 15 schematically shows an example of the configuration of the pixel array section 100A and its surroundings of the photodetector 3A shown in Figure 14. The photodetector 3A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0182] In this modified example, the photodetector 3A is further provided with separation grooves 75X in the pixel array section 100A. Except for this point, the photodetector 3A has substantially the same configuration as the photodetector 3 of the third embodiment described above.

[0183] Here, the separation groove 75X corresponds to a specific example of the "first separation groove" as one embodiment of the present disclosure, and the separation groove 75 corresponds to a specific example of the "second separation groove" as one embodiment of the present disclosure.

[0184] The separation groove 75X, like the separation groove 75, separates the spacer layer 24 and is provided in the pixel array section 100A, for example, as shown in Figures 14 and 15. The separation groove 75X penetrates the light guide section 27 and the spacer layer 54 from the light incident side S1, and further penetrates the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom. The width of the separation groove 75X is preferably, for example, one pixel or less. The separation groove 75X may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less. Similar to the separation groove 75, an inorganic layer 54B and a medium 27B are embedded in the separation groove 75X.

[0185] In this modified optical detection device 3A, a separation groove 75X is further provided within the pixel array section 100A. This further prevents displacement of the light guide section 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B, compared to the third embodiment described above. Therefore, it is possible to further improve the optical characteristics.

[0186] (6-2. Modification 5) Figure 16 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 3B) according to Modification 5 of the present disclosure. The photodetector 3B is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0187] In the third embodiment and modification 4 described above, an example was shown in which the surface of the inorganic layer 54B constituting the spacer layer 54 is flattened, but the invention is not limited to this. In this modified photodetector 3B, the step in the inorganic layer 54B that occurs when the light-shielding film 21, partition wall 22, and color filter 73 are stacked and cover the laminated film is left as is in the OPB region 100C. Except for this point, the photodetector 3B has substantially the same configuration as the photodetector 3 of the third embodiment described above.

[0188] In this modified photodetector 3B, the step in the spacer layer 54, which is created by covering the laminated film in which the light-shielding film 21, partition wall 22, and color filter 73 are stacked in the OPB region 100C, is left as is, and this can be used as a means to physically prevent misalignment of the light guide portion 27 under reliability load. This further prevents misalignment of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B.

[0189] <7. Fourth Embodiment> Figure 23 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 4) according to the fourth embodiment of the present disclosure. The photodetector 4 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0190] [Configuration of the Photodetector] As described above, the photodetector 4 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 50 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the second embodiment described above, the photodetector 4 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 50, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 50 includes a light-guiding section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The light detection device 4 has a spacer layer 54 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 50. The spacer layer 54 is constructed by stacking an organic layer 54A and an inorganic layer 54C in order from the semiconductor substrate 11 side. In this embodiment, the organic layer 54A of the spacer layer 54 is provided with a plurality of separation grooves (separation grooves 55A, 55B, 55C) that surround the pixel array section 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom of each of the separation grooves 55A, 55B, and 55C, and each of the separation grooves 55A, 55B, and 55C is embedded by the inorganic layer 54C.

[0191] Here, the spacer layer 54 corresponds to a specific example of the "spacer layer" as one embodiment of the present disclosure. The inorganic layer 54C corresponds to a specific example of the "protective film" as one embodiment of the present disclosure. The separation grooves 55A, 55B, and 55C correspond to specific examples of the "separation groove" and the "third separation groove" as one embodiment of the present disclosure.

[0192] The light-receiving unit 10, similar to the second embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0193] The optical layer 50 has the same configuration as the optical layer 20 of the second embodiment, except for the spacer layer 54. That is, the optical layer 50 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0194] The spacer layer 54 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 54 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0195] The spacer layer 54 has a structure in which an organic layer 54A formed using an organic material and an inorganic layer 54C formed using an inorganic material are stacked in this order from the light-receiving section 10 side. The inorganic layer 54C protects the surface of the light-shielding film 21, partition wall 22, and color filter 23 provided on the light-receiving section 10, or the organic layer 54A that covers these stacked films, and also fills in any steps in the organic layer 54A to form a flat surface. In this embodiment, the inorganic layer 54C also serves as a protective film that fills the separation grooves 55A, 55B, and 55C as described above.

[0196] Examples of constituent materials for the organic layer 54A include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 54C include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO). The thickness of the organic layer 54A is not particularly limited, but the thickness of the inorganic layer 54C that fills the separation grooves 55A, 55B, and 55C is preferably, for example, 500 nm to 5000 nm.

[0197] The separation grooves 55A, 55B, and 55C each separate the spacer layer 54, similar to the separation groove 55 in the second embodiment described above, and are provided so as to surround the pixel array portion 100A. The separation grooves 55A, 55B, and 55C each penetrate the organic layer 54A of the spacer layer 54, and further penetrate the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at their bottom surfaces. The width of the separation grooves 55A, 55B, and 55C is preferably, for example, 100 nm or more and 20,000 nm or less. The separation groove 55 may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0198] The separation grooves 55A, 55B, and 55C are provided in this order, starting from a position close to the pixel array section 100A. Separation groove 55A is provided, for example, around the OPB region 100C in a plan view. Separation groove 55B is provided, for example, above a pad section (e.g., electrode 32) that is located outside the OPB region 100C and connected to an external electrode or external circuit in a plan view, and the opening H through which wiring connecting electrode 32 and the external electrode is provided is located inside separation groove 55B. Separation groove 55C is provided in the scribe section T when cutting multiple photodetectors that are formed together in the manufacturing process of the photodetector. Therefore, in a plan view, separation groove 55C is provided at the edge of the semiconductor substrate 11, and the outer side of the pair of sides that form the groove, for example, the side facing each other in the X-axis direction in Figure 23, is separated by the cutting process.

[0199] The separation grooves 55A, 55B, and 55C are embedded by an inorganic layer 54C, as shown in Figure 23. In other words, the separation grooves 55A, 55B, and 55C are embedded by a protective film which is a single layer of the same material as the inorganic layer 54C. The inorganic layer 54C embedded in the separation grooves 55A, 55B, and 55C may have seams formed during its deposition, as shown by the dotted lines in Figure 23, or it may have voids formed inside. By embedding the separation grooves 55A, 55B, and 55C in this way, for example by an inorganic layer 54C, the intrusion of moisture into the organic layer 54A is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 24B is prevented.

[0200] Furthermore, in this embodiment, the corners X of the organic layer 54A separated by the separation grooves 55A, 55B, and 55C are rounded, as shown in Figure 23. In other words, the corners X of the organic layer 54A separated by the separation grooves 55A, 55B, and 55C have curvature. The rounding of the corners X is formed during the etching process when forming the separation grooves 55A, 55B, and 55C.

[0201] [Function and Effects] In the photodetector 4 of this embodiment, a spacer layer 54 is provided between the semiconductor substrate 11 having a photoelectric conversion unit 12 and the light guide unit 27. The spacer layer 54 is constructed by stacking an organic layer 54A and an inorganic layer 54C in that order from the semiconductor substrate 11 side. The organic layer 54A is provided with a plurality of separation grooves (separation grooves 55A, 55B, 55C) that penetrate, for example, to surround the pixel array unit 100A in a plan view. Of the plurality of separation grooves, separation groove 55B is provided above the pad unit (for example, the electrode 32) in a plan view, and the opening H, in which the electrode 32 is exposed on the bottom surface, is located inside the separation groove 55B. Separation groove 55C is provided in the scribe unit T. As a result, in the opening H and the scribe unit T, as shown in Figure 23, the ends of the organic layer 54A are covered by the inorganic layer 54C, and only the inorganic layer 54C is exposed. Therefore, the intrusion of moisture through the organic layer 54A from the opening H and the scribe unit T is reduced.

[0202] Furthermore, in this embodiment, multiple separation grooves (separation grooves 55A, 55B, 55C) are provided so as to surround the pixel array portion 100A in a plan view. Compared to the first to third embodiments described above, this further prevents displacement of the light guide portion 27 caused by the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 54C.

[0203] Furthermore, in this embodiment, the corners X of the organic layer 54A separated by the separation grooves 55A, 55B, and 55C are rounded, thereby suppressing the occurrence of cracks due to localized stress concentration.

[0204] As described above, the light detection device 4 of this embodiment can further improve reliability compared to the light detection devices (light detection device 1) of the first to third embodiments described above.

[0205] Furthermore, in the photodetector 4 of this embodiment, as described above, at the opening H, the edges of the organic layer 54A are covered by the inorganic layer 54C, and only the inorganic layer 54C is exposed. This reduces the possibility of voids occurring during the opening H formation process. Therefore, it is possible to improve light scattering and reliability degradation caused by voids.

[0206] <8. Fifth Embodiment> Figure 24 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 5) according to the fifth embodiment of the present disclosure. Figure 25 schematically shows an example of the configuration of the pixel array section 100A and its surroundings of the photodetector 5 shown in Figure 24. The photodetector 5 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0207] [Configuration of the Photodetector] As described above, the photodetector 5 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 50 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the second embodiment described above, the photodetector 5 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 50, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 50 includes a light guide section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The photodetector 5 has a spacer layer 54 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 50. The spacer layer 54 is constructed by stacking an organic layer 54A and an inorganic layer 54C in order from the semiconductor substrate 11 side. In this embodiment, the organic layer 54A of the spacer layer 54 is provided with pad sections (for example, a plurality of electrodes 32) that are connected to external electrodes or external circuits and are arranged to surround the pixel array section 100A in a plan view, as shown in Figure 25, for example, and a separation groove 55 that is continuous with the scribe section T when cutting a plurality of photodetectors that are formed all at once in the manufacturing process of the photodetector. The semiconductor substrate 11 is exposed at the bottom of the separation groove 55, and the separation groove 55 is embedded by the inorganic layer 54C.

[0208] Here, the spacer layer 54 corresponds to a specific example of a "spacer layer" as one embodiment of the present disclosure. The inorganic layer 54C corresponds to a specific example of a "protective film" as one embodiment of the present disclosure. The separation groove 55 corresponds to a specific example of a "separation groove" as one embodiment of the present disclosure.

[0209] The light-receiving unit 10, similar to the second embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0210] The optical layer 50 has the same configuration as the optical layer 20 of the second embodiment, except for the spacer layer 54. That is, the optical layer 50 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0211] The spacer layer 54 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 54 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0212] The spacer layer 54 has a structure in which an organic layer 54A formed using an organic material and an inorganic layer 54C formed using an inorganic material are stacked in this order from the light-receiving section 10 side. The inorganic layer 54C protects the surface of the light-shielding film 21, partition wall 22, and color filter 23 provided on the light-receiving section 10, or the organic layer 54A covering these stacked films, and also fills in any steps in the organic layer 54A to form a flat surface. In this embodiment, as described above, the inorganic layer 54C also serves as a protective film that fills the separation groove 55.

[0213] Examples of constituent materials for the organic layer 54A include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 54C include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO). The thickness of the organic layer 54A is not particularly limited, but the thickness of the inorganic layer 54C that fills the separation grooves 55A, 55B, and 55C is preferably, for example, 500 nm to 5000 nm.

[0214] The separation groove 55 separates the spacer layer 54, similar to the second embodiment described above, and is provided so as to surround the pixel array portion 100A. The separation groove 55 penetrates the organic layer 54A of the spacer layer 54, and further penetrates the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom surface. The separation groove 55 may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0215] As described above, the separation groove 55 is provided in a plan view, for example, in a plurality of electrodes 32 (pad portions) arranged to surround the pixel array portion 100A, and in a manufacturing process for a plurality of photodetectors, it is provided in a continuous manner with the scribe portion T used when cutting the photodetectors that are formed collectively. In other words, in a plan view, the separation groove 55 is provided, for example, from the outside of the OPB region 100C to the edge of the semiconductor substrate 11.

[0216] As shown in Figure 24, the separation groove 55 is embedded by an inorganic layer 54C. In other words, the separation groove 55 is embedded by a protective film which is a single layer of the same material as the inorganic layer 54C. The inorganic layer 54C embedded in the separation groove 55 may have seams that occur during film formation as described above, or it may have voids formed inside. By embedding the separation groove 55 in this way, for example by an inorganic layer 54C, the intrusion of moisture into the organic layer 54A is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 24B is prevented.

[0217] [Function and Effects] In the photodetector 5 of this embodiment, a separation groove 55 is provided between the semiconductor substrate 11 having the photoelectric conversion unit 12 and the light guide unit 27. The organic layer 54A of the spacer layer 54, in which an organic layer 54A and an inorganic layer 54C are stacked in that order from the semiconductor substrate 11 side, is provided so that it penetrates the organic layer 54A, for example, so as to surround the pixel array unit 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom of the separation groove 55, and the medium 27B constituting the light guide unit 27 is embedded inside so that a protective film extends to the side and bottom surfaces of the separation groove 55. As a result, as in the first embodiment described above, the intrusion of moisture through the organic layer 54A is reduced, and displacement of the light guide unit 27 caused by the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 54C is prevented.

[0218] Furthermore, in the photodetector 5 of this embodiment, the separation groove 55 is provided continuously with a plurality of electrodes 32 (pad portions) arranged to surround the pixel array portion 100A in a plan view, and with the scribe portion T used when cutting a plurality of photodetectors that are formed collectively during the manufacturing process of the photodetector. This makes it possible to reduce chip size and manufacturing costs compared to the case in the fourth embodiment described above, where separation grooves 55B and 55C are provided individually for each of the pad portion and the scribe portion T.

[0219] As described above, the optical detection device 5 of this embodiment makes it possible to improve reliability while reducing chip size and manufacturing costs.

[0220] <9. Modified Examples> (9-1. Modified Example 6) Figure 26 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 5A) according to Modified Example 6 of the present disclosure. The photodetector 5A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0221] In this modified example, the photodetector 5A has a plurality of uneven structures Y provided on the surface of the semiconductor substrate 11 exposed at the bottom of the separation groove 55. The plurality of uneven structures Y are for reducing the reflection of light obliquely incident on the peripheral portion 100B on the surface of the semiconductor substrate 11 exposed at the bottom of the separation groove 55. Each uneven structure Y has, for example, an inverted pyramidal shape, and its side surface is composed of, for example, a Si(111) plane. Each uneven structure Y is not limited to this and may be prismatic or have other shapes. The plurality of uneven structures Y can be formed by etching using photolithography technology or self-assembling materials.

[0222] As described above, in the modified photodetector 5A, a plurality of uneven structures Y are provided on the surface of the semiconductor substrate 11 exposed at the bottom of the separation groove 55, thereby reducing the reflection of light obliquely incident on the peripheral portion 100B of the surface of the semiconductor substrate 11 exposed at the bottom of the separation groove 55.

[0223] <10. Sixth Embodiment> Figure 27 schematically shows an example of the cross-sectional configuration of the photodetector (photodetector 6) according to the sixth embodiment of the present disclosure. Figure 28 schematically shows another example of the cross-sectional configuration of the photodetector 6 according to the sixth embodiment of the present disclosure. The photodetector 6 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0224] [Configuration of the Photodetector] As described above, the photodetector 6 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 80 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the second embodiment described above, the photodetector 6 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 80, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 80 includes a light guide section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A.

[0225] The light detection device 6 has a spacer layer 54 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 80. The spacer layer 54 consists of an organic layer 54A and an inorganic layer 54B stacked in order from the semiconductor substrate 11 side, and the organic layer 54A has a plurality of separation grooves (separation grooves 85A, 85B) that surround the pixel array section 100A in a plan view. The semiconductor substrate 11 is exposed at the bottom of each of the separation grooves 85A, 85B. The light detection device 6 further has a microlens layer 81 provided between the organic layer 54A and the inorganic layer 54B constituting the spacer layer 54, and a plurality of separation grooves (separation grooves 87A, 87B) that separate the microlens layer 81. The microlens layer 81 consists of a first layer 81A having a plurality of microlenses on its surface and a second layer 81B that flattens the surface of the first layer 81A, stacked in order from the semiconductor substrate 11 side. The separation grooves 87A and 87B are located inside the separation grooves 85A and 85B, respectively, and excavate the semiconductor substrate 11 to a deeper position than the separation grooves 85A and 85B, and are filled with an inorganic layer 54B.

[0226] Here, the spacer layer 54 corresponds to a specific example of the "spacer layer" as one embodiment of the present disclosure. The first layer 81A corresponds to a specific example of the "protective film" as one embodiment of the present disclosure. The separation grooves 85A and 85B correspond to a specific example of the "separation groove" as one embodiment of the present disclosure. The microlens layer 81 corresponds to a specific example of the "microlens layer" as one embodiment of the present disclosure. The separation grooves 87A and 87B correspond to a specific example of the "fourth separation groove" as one embodiment of the present disclosure.

[0227] The light-receiving unit 10, similar to the second embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0228] The optical layer 80 has the same configuration as the optical layer 20 of the second embodiment, except for the spacer layer 54. That is, the optical layer 80 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 54, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0229] The spacer layer 54 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 54 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0230] The spacer layer 54 has a configuration in which an organic layer 54A formed using an organic material, a microlens layer 81, and an inorganic layer 54B formed using an inorganic material are stacked in this order from the light-receiving section 10 side. The organic layer 54A is for forming a flat surface while filling in the steps of the light-shielding film 21, partition wall 22, and color filter 23 or their stacked films provided on the light-receiving section 10. The inorganic layer 54B is for protecting the surface of the microlens layer 81. As described above, the microlens layer 81 has a first layer 81A having a plurality of microlenses on its surface and a second layer 81B that flattens the surface of the first layer 81A stacked in this order from the semiconductor substrate 11 side. In other words, the spacer layer 54 has a configuration in which the organic layer 54A, the first layer 81A, the second layer 81B, and the inorganic layer 54B are stacked in this order from the light-receiving section 10 side. The first layer 81A is provided with a plurality of microlenses for each unit pixel P, for example. The microlens is used to focus light incident from above toward the semiconductor substrate 11, which serves as the light-receiving surface. The shape of the microlens is not particularly limited, and various lens shapes such as a hemispherical shape as shown in Figure 27, a columnar shape as shown in Figure 28, or a semi-cylindrical shape can be used. The first layer 81A is formed using an inorganic material, similar to the inorganic layer 65B. The second layer 81B is formed using an organic material, similar to the organic layer 54A. In addition, other films, such as an anti-reflective film, may be provided between the first layer 81A and the second layer 81B.

[0231] Examples of constituent materials for the organic layer 54A and the second layer 81B include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 54B and the first layer 81A include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO). The thickness of the organic layer 54A is not particularly limited, but the thickness of the inorganic layer 54B that fills the separation grooves 87A and 87B is preferably, for example, 500 nm or more and 5000 nm or less.

[0232] The separation grooves 85A and 85B each separate the spacer layer 54, similar to the separation groove 55 in the second embodiment described above, and are provided so as to surround the pixel array portion 100A. The separation grooves 85A and 85B each penetrate the organic layer 54A of the spacer layer 54, and further penetrate the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at their bottom surfaces. The width of the separation grooves 85A and 85B is preferably, for example, 100 nm or more and 20,000 nm or less. The separation grooves 85A and 85B may further excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm or more and 10 μm or less.

[0233] The separation grooves 85A and 85B are provided in this order, starting from a position close to the pixel array section 100A. In a plan view, the separation groove 85A is provided, for example, around the OPB region 100C. In a plan view, the separation groove 85B is provided, for example, above a pad portion (e.g., electrode 32) that is connected to an external electrode or external circuit and is located outside the OPB region 100C, and the opening H through which wiring connecting electrode 32 to the external electrode, etc., is provided is located inside the separation groove 85B. The first layer 81A, which constitutes the microlens layer 81, extends from the side and bottom surfaces of the separation grooves 85A and 85B. The second layer 81B, which also constitutes the microlens layer 81, is further embedded in the separation grooves 85A and 85B.

[0234] The separation grooves 87A and 87B are located inside the separation grooves 85A and 85B, respectively, and as described above, they excavate the semiconductor substrate 11 to a deeper position than the separation grooves 85A and 85B, and are filled with the inorganic layer 54B. In other words, the separation grooves 87A and 87B are embedded with a protective film which is a single layer of the same material as the inorganic layer 54B. Similar to the separation grooves 85A and 85B, the separation grooves 87A and 87B excavate the semiconductor substrate 11 from the first surface side to a depth of, for example, 0.01 μm to 10 μm.

[0235] The inorganic layer 54B embedded in the separation grooves 87A and 87B may have seams formed during film formation, as in the fourth embodiment described above, or it may have voids formed inside. By embedding the separation grooves 87A and 87B with, for example, the inorganic layer 54B, the intrusion of moisture into the organic layer 54A and the second layer 81B is reduced, and displacement of the light guide portion 27 formed on the spacer layer 24 due to the difference in thermal expansion coefficients between the organic layer 54A and the inorganic layer 24B is prevented.

[0236] [Manufacturing Method for the Light Detection Device] Figures 29A to 29H show the manufacturing method for the light detection device 6 in order of steps.

[0237] First, as shown in Figure 29A, a light-shielding film 21, a partition wall 22, and a color filter 23 are formed sequentially on the first surface 11S1 of the semiconductor substrate 11.

[0238] Next, as shown in Figure 29B, for example, an organic layer 54A is deposited as a spacer layer 54 using the CVD method, and then a SiN film 81A-1 is deposited as the first layer 81A, for example. After that, a resist film 121 for forming microlenses is patterned on the SiN film 81A-1 using photolithography technology.

[0239] Next, as shown in Figure 29C, for example, multiple microlenses are formed on the SiN film 81A-1 using dry etching.

[0240] Next, as shown in Figure 29D, a resist film (not shown) is patterned on the SiN film 81A-1 using photolithography. Then, for example, separation grooves 85A and 85B are formed by dry etching, penetrating the SiN film 81A-1, the organic layer 54A, and the dielectric layer 14, and reaching the semiconductor substrate 11. After that, the resist film is removed.

[0241] Next, as shown in Figure 29E, an additional SiN film is deposited, for example, using the CVD method. This provides multiple microlenses for each unit pixel P, and forms a first layer 81A that extends to the side and bottom surfaces of the separation grooves 85A and 85B.

[0242] Next, as shown in Figure 29F, a second layer 81B is formed using, for example, a coating method. This fills the separation grooves 85A and 85B with the second layer 81B.

[0243] Next, as shown in Figure 29G, for example, a resist film (not shown) is patterned on the second layer 81B using photolithography technology, and then, for example, separation grooves 87A and 87B are formed using dry etching, penetrating the second layer 81B, the first layer 81A, the organic layer 54A, and the dielectric layer 14, and reaching the semiconductor substrate 11.

[0244] Next, as shown in Figure 29H, after removing the resist film, an inorganic layer 54B is formed using, for example, a CVD method. This fills the separation groove 55 with the inorganic layer 54B. Then, in the same manner as in the first embodiment described above, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28 are formed sequentially on the spacer layer 54. With these steps, the light detection device 6 shown in Figure 27 is completed.

[0245] The manufacturing method described above is merely one example, and other manufacturing methods may be used.

[0246] [Function and Effects] In the photodetector 6 of this embodiment, a spacer layer 54 is provided between the semiconductor substrate 11 having the photoelectric conversion unit 12 and the light guide unit 27, in which an organic layer 54A and an inorganic layer 54B are stacked in that order, and a microlens layer 81 is provided between the organic layer 54A and the inorganic layer 54B. The microlens layer 81 is stacked from the semiconductor substrate 11 side, in order, with a first layer 81A having a plurality of microlenses on its surface and a second layer 81B that flattens the surface of the first layer 81A. In the photodetector 6 of this embodiment, further, a plurality of separation grooves (separation grooves 85A, 85B) are provided in the organic layer 54A, for example, that penetrate to surround the pixel array unit 100A in a plan view, and separation grooves 87A, 87B are provided which are arranged inside the separation grooves 85A, 85B and excavate the semiconductor substrate 11 to a deeper position than the separation grooves 85A, 85B. The inorganic layer 54B is embedded in the separation grooves 87A, 87B. As a result, even when a microlens layer 81 is provided between the semiconductor substrate 11 constituting the light-receiving section 10 and the light-guide section 27 constituting the optical layer 80, the intrusion of moisture through the organic layer 54A and the second layer 81B constituting the microlens layer 81 is reduced, similar to the first embodiment described above. Furthermore, displacement of the light-guide section 27 caused by the difference in thermal expansion coefficients between the organic layer 54A and the first layer 81A formed using organic materials and the second layer 81B and inorganic layer 54B formed using inorganic materials is prevented.

[0247] As described above, the light detection device 6 of this embodiment can improve reliability, similar to the light detection device (light detection device 1) of the first embodiment described above.

[0248] <11. Modification> (11-1. Modification 7) Figure 30 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 6A) according to Modification 7 of the present disclosure. The photodetector 6A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0249] In this modified example, the photodetector 6A omits the organic layer 54A, and the first layer 81A and the second layer 81B constituting the microlens layer 81 are formed using organic materials. In other words, the microlens layer 81 can be considered as the organic layer 54A constituting the spacer layer 54. When the entire microlens layer 81 is formed using organic materials, the separation grooves 85A and 85B described above can be omitted.

[0250] Even with this configuration, the modified photodetector 6A can achieve the same effects as the photodetector 6 of the sixth embodiment described above.

[0251] (11-2. Modification 8) Figure 31 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 6B) according to Modification 8 of the present disclosure. The photodetector 6B is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0252] In the sixth embodiment described above, an example was shown in which the second layer 81B is embedded in the separation grooves 85A and 85B, but the embodiment is not limited to this. The separation grooves 85A and 85B may be provided only with the first layer 81A extending to the side and bottom surfaces, as shown in Figure 31.

[0253] Even with this configuration, the modified photodetector 6B can achieve the same effects as the photodetector 6 of the sixth embodiment described above.

[0254] (11-3. Modification 9) Figure 32 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 6C) according to Modification 9 of the present disclosure. The photodetector 6C is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0255] In the sixth embodiment described above, an example was shown in which the separation grooves 87A and 87B are arranged inside the separation grooves 85A and 85B, respectively, but the embodiment is not limited to this. The separation grooves 87A and 87B may be provided in positions different from those of the separation grooves 85A and 85B. The photodetector 6C is configured such that the separation groove 87A is located outside the separation groove 85A.

[0256] Even with this configuration, the modified photodetector 6C can achieve the same effects as the photodetector 6 of the sixth embodiment described above.

[0257] <12. Seventh Embodiment> Figure 33 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 7) according to the seventh embodiment of the present disclosure. Figure 34 schematically shows an example of the configuration of the pixel array section 100A and its surroundings in the photodetector 7 shown in Figure 33. Figure 35 schematically shows another example of the configuration of the pixel array section 100A and its surroundings in the photodetector 7 shown in Figure 33. The photodetector 7 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0258] [Configuration of the Photodetector] As described above, the photodetector 7 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 20 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the first embodiment described above, the photodetector 7 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 20, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 20 includes a light guide section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The light detection device 7 has a spacer layer 24 between the semiconductor substrate 11 that constitutes the light receiving section 10 and the light guide section 27 that constitutes the optical layer 20. The spacer layer 24 is constructed by stacking an organic layer 24A and an inorganic layer 24B in order from the semiconductor substrate 11 side. In this embodiment, a stepped portion 91 is provided between the semiconductor substrate 11 and the spacer layer 24 in the peripheral portion 100B.

[0259] Here, the spacer layer 24 corresponds to one specific example of the "spacer layer" as one embodiment of the present disclosure. The stepped portion 91 corresponds to one specific example of the "stepped portion" as one embodiment of the present disclosure.

[0260] The light-receiving unit 10, similar to the first embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0261] The optical layer 20 has the same configuration as the optical layer 20 of the first embodiment, except for the spacer layer 24. That is, the optical layer 20 includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 24, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side.

[0262] The spacer layer 24 is provided between the light-receiving section 10 and the light-guiding section 27. The spacer layer 24 is formed to extend across the pixel array section 100A and the peripheral section 100B so as to be laminated on the partition wall 22 and color filter 23 provided in the pixel array section 100A, and on the light-shielding film 21, partition wall 22 and color filter 23 provided in the OPB area 100C.

[0263] The spacer layer 24 has a structure in which an organic layer 24A formed using an organic material and an inorganic layer 24B formed using an inorganic material are stacked in this order from the light-receiving section 10 side. The inorganic layer 24B protects the surface of the light-shielding film 21, partition wall 22, and color filter 23 provided on the light-receiving section 10, or the organic layer 24A that covers these stacked films, and also fills in any steps in the organic layer 24A to form a flat surface.

[0264] Examples of constituent materials for the organic layer 24A include resin materials such as acrylic, styrene, or epoxy. Examples of constituent materials for the inorganic layer 24B include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO).

[0265] The stepped portion 91 is intended to suppress the expansion of the organic layer 24A while creating a space for stress relief in the organic layer 24A during expansion. Furthermore, the stepped portion 91 reduces the surface step of the organic layer 24A, thereby reducing the amount of polishing required for the inorganic layer 24B. In a plan view, the stepped portion 91 is provided continuously outside the OPB region 100C, for example, surrounding the pixel array portion 100A, as shown in Figure 34. Alternatively, in a plan view, the stepped portion 91 may be provided intermittently outside the OPB region 100C, for example, as shown in Figure 35. The thickness of the stepped portion 91 is preferably greater than the thickness of the color filter 23. Specifically, the thickness of the stepped portion 91 is preferably such that the height of the organic layer 24A formed on the laminated film of the light-shielding film 21, partition wall 22, and color filter 23 provided on the light-receiving portion 10 provided in the OPB region 100C is approximately the same as the height of the organic layer 24A formed on the stepped portion 91, as shown in Figure 32. This reduces the amount of polishing required for the inorganic layer 24B.

[0266] Examples of materials that make up the stepped portion 91 include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (AlO).

[0267] [Function and Effects] In the photodetector 7 of this embodiment, a stepped portion 91 surrounding the pixel array portion 100A is provided between the semiconductor substrate 11 having the photoelectric conversion portion 12 in the peripheral portion 100B and the light guide portion 27. As a result, the expansion of the organic layer 24A is suppressed by the stepped portion 91, and displacement of the light guide portion 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B is prevented.

[0268] As described above, the light detection device 7 of this embodiment can improve reliability, similar to the light detection device 1 of the first embodiment.

[0269] Furthermore, in the photodetector 7 of this embodiment, a portion of the organic layer 24A is formed on the stepped portion 91, which creates a space for stress relief in the organic layer 24A during expansion. Moreover, in the photodetector 7 of this embodiment, the stepped portion 91 reduces the step height on the surface of the organic layer 24A, thus reducing the amount of polishing required for the inorganic layer 24B. Therefore, reliability can be further improved.

[0270] <13. Modification> (13-1. Modification 10) Figure 36 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 7A) according to Modification 10 of the present disclosure. The photodetector 7A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0271] In this modified example, the photodetector 7A has a plurality of stepped sections (stepped sections 91A, 91B) extending from the pixel array section 100A toward the peripheral section 100B. Except for this point, the photodetector 7A in this modified example has substantially the same configuration as the photodetector 7 of the seventh embodiment described above.

[0272] In this modified photodetector 7A, as described above, stepped portions 91A and 91B are provided from the pixel array portion 100A toward the peripheral portion 100B. Therefore, compared to the photodetector 7 of the seventh embodiment, it is possible to better prevent the displacement of the light guide portion 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B.

[0273] (13-2. Modification 11) Figure 37 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 7B) according to Modification 11 of the present disclosure. The photodetector 7B is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0274] The light-shielding films 21 and partitions 22 stacked on top of each other, and the color filters 23 including the red filter 23R, green filter 23G, and blue filter 23B filled in the openings of the light-shielding films 21 and partitions 22, may be provided over the pixel array portion 100A and the peripheral portion 100B, similar to the third embodiment described above.

[0275] Even with this configuration, the modified photodetector 7B can achieve the same effects as the photodetector 7 of the seventh embodiment described above.

[0276] (13-3. Modification 12) Figure 38 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 7C) according to Modification 12 of the present disclosure. The photodetector 7C is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0277] A recess 91X may be formed on the upper surface of the stepped portion 91, as shown in Figure 38. This recess 91X further prevents displacement of the light guide portion 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B.

[0278] <14. Eighth Embodiment> Figure 39 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 8) according to the eighth embodiment of the present disclosure. The photodetector 8 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and, similar to the first embodiment described above, is, for example, a so-called back-illuminated photodetector.

[0279] [Configuration of the Photodetector] As described above, the photodetector 8 is a back-illuminated imaging device, and each of the multiple unit pixels P arranged in a matrix in two dimensions in the pixel array section 100A has a configuration in which, for example, a light-receiving section 10, an optical layer 20 provided on the light incident side S1 of the light-receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light-receiving section 10 are stacked. Similar to the first embodiment described above, the photodetector 8 has a pixel array section 100A in which the multiple unit pixels P are arranged in a matrix in two dimensions, and a peripheral section 100B surrounding the pixel array section 100A. The light-receiving section 10, the optical layer 20, and the multilayer wiring layer 30 are provided, for example, across the pixel array section 100A and the peripheral section 100B. The optical layer 20 includes a light guide section 27, which is composed of, for example, a plurality of structures 27A that are nanostructures and a medium 27B that fills the spaces between adjacent structures 27A. The light detection device 8 has a spacer layer 24 between the semiconductor substrate 11 constituting the light receiving section 10 and the light guide section 27 constituting the optical layer 20. The spacer layer 24 consists of an organic layer 24A and an inorganic layer 24B stacked in order from the semiconductor substrate 11 side. In the organic layer 24A of the spacer layer 24, a separation groove 95 is provided so as to surround the pixel array section 100A in a plan view. The inorganic layer 24B and the medium 27B constituting the light guide section 27 extend from the side and bottom surfaces of the separation groove 95. In this embodiment, a recess 27V is formed on the light guide section 27 extending from the side and bottom surfaces of the separation groove 95, and an embedded layer 92 is provided to fill this recess 27V.

[0280] Here, the light guide portion 27 corresponds to one specific example of the "light guide portion" as one embodiment of the present disclosure. The recess 27V corresponds to one specific example of the "recess" as one embodiment of the present disclosure. The separation groove 95 corresponds to one specific example of the "separation groove" as one embodiment of the present disclosure. The embedded layer 92 corresponds to one specific example of the "embedded layer" as one embodiment of the present disclosure.

[0281] The light-receiving unit 10, similar to the first embodiment described above, includes a semiconductor substrate 11 having opposing first surfaces 11S1 and second surfaces 11S2, and a plurality of photoelectric conversion units 12 embedded in the semiconductor substrate 11. The first surface 11S1 of the semiconductor substrate 11 is further provided with a dielectric layer 14 that also serves to prevent reflection on the first surface 11S1 of the semiconductor substrate 11. The light-receiving unit 10 further includes a pixel separation unit 13.

[0282] The optical layer 20, similar to the first embodiment described above, includes, for example, a light-shielding film 21, a partition wall 22, a color filter 23, a spacer layer 24, an anti-reflective film 26, a light guide portion 27, and an anti-reflective film 28, and is configured to guide light incident from the light incident side S1 to the light-receiving portion 10 side. Except for the light-shielding film 21 and the partition wall 22, the optical layer 20 has the same configuration as the optical layer 20 of the first embodiment described above.

[0283] The light-shielding film 21 is provided at the boundary between adjacent unit pixels P in the pixel array section 100A and is a frame having an opening for each unit pixel P. The light-shielding film 21 is also provided in the OPB area 100C. In the OPB area 100C, the light-shielding film 21 is divided by an opening 21H provided near the laminated film of the light-shielding film 21, the partition wall 22, and the color filter 23, as shown in Figure 39, for example. The opening 21H is provided so as to surround the pixel array section 100A in a plan view, for example, and is covered by the blue filter 23B.

[0284] The light-shielding film 21 can be formed using, for example, tungsten (W), silver (Ag), copper (Cu), titanium (Ti), aluminum (Al), or alloys thereof.

[0285] The partition wall 22 is laminated on the light-shielding film 21. The partition wall 22 is provided at the boundary between adjacent unit pixels P in the pixel array section 100A, and is provided as a frame having an opening for each unit pixel P. The partition wall 22 is also provided in the OPB region 100C. In the OPB region 100C, the partition wall 22 is divided near the laminated film of the light-shielding film 21, the partition wall 22, and the color filter 23, similar to the light-shielding film 21. Specifically, as shown in Figure 39, for example, the partition wall 22 is divided from in front of the opening 21H that divides the light-shielding film 21 to the outside of the blue filter 23B that covers the opening 21H.

[0286] The partition wall 22 is designed to prevent light incident at an oblique angle from the light incident side S1 from leaking into adjacent unit pixels P. The partition wall 22 is constructed using a material with a lower refractive index than the color filter 23, for example. Specifically, the partition wall 22 is made of silicon oxide (SiO).

[0287] The separation groove 95 separates the spacer layer 24, similar to the separation groove 25 in the first embodiment described above, and is provided in the OPB region 100C so as to surround the pixel array portion 100A. Specifically, the separation groove 95 is provided so as to surround the pixel array portion 100A outside the opening 21H that divides the light-shielding film 21. The separation groove 95 penetrates the organic layer 24A of the spacer layer 24, and a partition wall 22A, which is laminated on the light-shielding film 21 extending outside the opening 21H, is exposed at its bottom surface.

[0288] The embedding layer 92 is intended to fill the depression 27V formed above the separation groove 95 and flatten its surface. The embedding layer 92 is formed using a material whose refractive index difference with the medium 27B is ±0.3 or less. For example, the embedding layer 92 is formed using a material having a refractive index of 1.4 to 1.8. This reduces flare in the depression 27V. Preferably, the embedding layer 92 is formed using a resin material. This relieves stress in the depression 27V portion. The embedding layer 92 can further reduce flare in the depression 27V by further including a dye material.

[0289] [Manufacturing Method for the Light Detection Device] Figures 40A to 40G show the manufacturing method for the light detection device 8 in order of steps.

[0290] First, as shown in Figure 40A, a light-shielding film 21, a partition wall 22, and a color filter 23 are sequentially formed on the first surface 11S1 of the semiconductor substrate 11. Then, for example, an organic layer 24A is deposited as a spacer layer 24 using the CVD method. Next, a resist film (not shown) is patterned on the organic layer 24A using photolithography technology. Then, for example, a separation groove 95 penetrating the organic layer 24A is formed using wet etching. After removing the resist film, for example, an inorganic layer 24B is deposited using the CVD method. Then, for example, the surface of the inorganic layer 24B is planarized using the CMP method so that, for example, the arithmetic mean roughness (Ra) is 0.5 or less, thereby forming the spacer layer 24.

[0291] Next, as shown in Figure 40B, an anti-reflective film 26 and a medium 27B are formed sequentially on the spacer layer 24.

[0292] Next, as shown in Figure 40C, after forming an embedded layer 92 to fill the depression 27V formed above the separation groove 95, the surfaces of the medium 27B and the embedded layer 92 are planarized using, for example, the CMP method.

[0293] Next, as shown in Figure 40D, a hard mask 122 is formed on the medium 27B and the embedding layer 92, and then a resist film 123 is patterned on the hard mask 122 using photolithography technology.

[0294] Next, as shown in Figure 40E, the medium 27B is processed, for example, by dry etching to form a plurality of openings 27H.

[0295] Next, as shown in Figure 40F, a TiO film 27X is formed to fill the multiple openings 27H.

[0296] Next, as shown in Figure 40G, for example, the TiO film 27X deposited on the medium 27B and the embedding layer 92 is removed using the CMP method to form a plurality of pillar-shaped structures 27A to provide the light guide portion 27, and the surface including the embedding layer 92 is flattened. After that, by depositing an anti-reflective film 28, the light detection device 8 shown in Figure 39 is completed.

[0297] The manufacturing method described above is merely one example, and other manufacturing methods may be used.

[0298] [Effects and Actions]

[0299] In the light detection device 8 of this embodiment, the surface is made flat by providing an embedded layer 92 in the recess 27V formed in the light guide portion 27 that constitutes the optical layer 20.

[0300] In the manufacturing process described above, if multiple structures 27A are formed while leaving a recess 27V, TiO films 27X constituting the multiple structures 27A are deposited in the recess 27V. The TiO films 27X deposited in the recess 27V remain even after the TiO films 27X deposited on the medium 27B using the CMP method described above are removed, causing a deterioration of flare.

[0301] In contrast, in this embodiment, the depressions 27V are filled with a filling layer 92 before the TiO film 27X is deposited, thereby flattening the surface and preventing the formation of the TiO film 27X on the depressions 27V.

[0302] As described above, the light detection device 8 of this embodiment makes it possible to prevent a decrease in image quality.

[0303] Furthermore, in the light detection device 8 of this embodiment, the use of a resin material for the embedded layer 92 makes it possible to relieve stress in the recessed portion 27V.

[0304] Furthermore, in the photodetector 8 of this embodiment, a separation groove 95 is provided in the organic layer 24A of the spacer layer 24, which is provided between the semiconductor substrate 11 having the photoelectric conversion unit 12 and the light guide unit 27. The organic layer 24A and inorganic layer 24B are stacked in that order from the semiconductor substrate 11 side. The separation groove 95 penetrates the organic layer 24A, for example, so as to surround the pixel array unit 100A in a plan view, and the inorganic layer 25B extends from the side and bottom of the separation groove 95. This reduces the intrusion of moisture through the organic layer 24A and prevents displacement of the light guide unit 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B.

[0305] Therefore, in the light detection device 8 of this embodiment, reliability can be improved, similar to the light detection device 1 of the first embodiment described above.

[0306] <15. Modification> (15-1. Modification 13) Figure 41 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 8A) according to Modification 13 of the present disclosure. The photodetector 8A is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0307] In the eighth embodiment described above, an example was shown in which a single-layer light guide section 27 is provided, but the invention is not limited to this. Multiple light guide sections can be stacked, and the light detection device 8A in this modified example has two layers of light guide sections (light guide sections 27 and 29) stacked, similar to the first modified example described above. Except for this point, the light detection device 8A in this modified example has substantially the same configuration as the light detection device 8 of the eighth embodiment described above.

[0308] As described above, in this modified photodetector 8A, a multi-stage light guide section 27, 29 is provided on the first surface 11S1 side of the semiconductor substrate 11. In the photodetector 8A, the recess 27V of the light guide section 27 is filled with the embedding layer 92 to flatten the surface, so that variations in, for example, the line width of the multiple structures 29A in the light guide section 29 provided on the light guide section 27 can be suppressed. Therefore, it is possible to improve variations in characteristics.

[0309] (15-2. Modification 14) Figure 42 schematically shows an example of a cross-sectional configuration of a photodetector (photodetector 8B) according to Modification 14 of the present disclosure. The photodetector 8B is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, similar to the first embodiment described above, for example, a so-called back-illuminated photodetector.

[0310] In this modified photodetector 8B, a separation groove 25 for separating the organic layer 24A is provided inside the opening 21H that divides the light-shielding film 21. The separation groove 25 is provided so as to surround the pixel array portion 100A together with the opening 21H in a plan view, for example. Similar to the first embodiment, the separation groove 25 penetrates the organic layer 24A from the light incident side S1 and also penetrates the dielectric layer 14 on the first surface 11S1 of the semiconductor substrate 11, with the semiconductor substrate 11 exposed at its bottom surface. The separation groove 25 is embedded, for example, by an inorganic layer 25B. Except for this point, the photodetector 8B in this modified example has substantially the same configuration as the photodetector 8 of the eighth embodiment.

[0311] As described above, in this modified example, the photodetector 8B has an organic layer 24A constituting the spacer layer 24, for example, that penetrates the pixel array portion 100A in a plan view, and a separation groove 25 is provided on its bottom surface, exposing the semiconductor substrate 11, and the separation groove 25 is embedded by the inorganic layer 25B. As a result, similar to the first embodiment, the intrusion of moisture through the organic layer 24A is reduced, and displacement of the light guide portion 27 caused by the difference in thermal expansion coefficients between the organic layer 24A and the inorganic layer 24B is prevented.

[0312] As described above, the modified optical detection device 8B makes it possible to improve reliability in addition to the effects of the eighth embodiment described above.

[0313] <16. Examples of Application>

[0314] (Application Example 1) Furthermore, the above-described light detection device (for example, light detection device 1) can be applied to various electronic devices such as imaging systems such as digital still cameras and digital video cameras, mobile phones equipped with imaging functions, or other devices equipped with imaging functions.

[0315] Figure 17 is a block diagram showing an example of the configuration of the electronic device 1000.

[0316] As shown in Figure 17, the electronic device 1000 includes an optical system 1001, a light detection device 1, and a DSP (Digital Signal Processor) 1002. The DSP 1002, memory 1003, display device 1004, recording device 1005, operating system 1006, and power supply system 1007 are connected via a bus 1008, and it is capable of capturing still and moving images.

[0317] The optical system 1001 is composed of one or more lenses and captures incident light (image light) from the subject and forms an image on the imaging surface of the light detection device 1.

[0318] The light detection device 1 converts the amount of incident light imaged onto the imaging surface by the optical system 1001 into an electrical signal on a pixel-by-pixel basis and supplies it to the DSP 1002 as a pixel signal.

[0319] The DSP 1002 performs various signal processing on the signal from the light detection device 1 to acquire an image, and temporarily stores the image data in the memory 1003. The image data stored in the memory 1003 is recorded in the recording device 1005 or supplied to the display device 1004 to display the image. The operation system 1006 accepts various operations from the user and supplies operation signals to each block of the electronic device 1000, and the power supply system 1007 supplies the power necessary to drive each block of the electronic device 1000.

[0320] (Application Example 2) Figure 18A schematically shows an example of the overall configuration of a photodetection system 2000 equipped with the above-described photodetector (for example, photodetector 1). Figure 18B shows an example of the circuit configuration of the photodetection system 2000. The photodetection system 2000 includes a light-emitting device 2001 as a light source that emits infrared light L2, and a photodetector 2002 as a light-receiving unit having a photoelectric conversion element. The above-described photodetector 1 can be used as the photodetector 2002. The photodetection system 2000 may further include a system control unit 2003, a light source drive unit 2004, a sensor control unit 2005, a light source side optical system 2006, and a camera side optical system 2007.

[0321] The photodetector 2002 can detect light L1 and light L2. Light L1 is light reflected from ambient light from the outside by the subject (object to be measured) 2100 (Figure 18A). Light L2 is light that has been emitted by the light-emitting device 2001 and then reflected by the subject 2100. Light L1 is, for example, visible light, and light L2 is, for example, infrared light. Light L1 is detectable in the photoelectric conversion unit of the photodetector 2002, and light L2 is detectable in the photoelectric conversion region of the photodetector 2002. Image information of the subject 2100 can be obtained from light L1, and distance information between the subject 2100 and the photodetector system 2000 can be obtained from light L2. The photodetector system 2000 can be mounted on, for example, electronic devices such as smartphones or mobile devices such as cars. The light-emitting device 2001 can be, for example, a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). As a detection method for the light L2 emitted from the light-emitting device 2001 by the photodetector 2002, for example, the iTOF method can be used, but is not limited to this. In the iTOF method, the photoelectric conversion unit can measure the distance to the subject 2100 by, for example, the time-of-flight (TOF). As a detection method for the light L2 emitted from the light-emitting device 2001 by the photodetector 2002, for example, the structured light method or the stereo vision method can also be used. For example, in the structured light method, the distance between the photodetector 2000 and the subject 2100 can be measured by projecting a predetermined pattern of light onto the subject 2100 and analyzing the degree of distortion of the pattern. In the stereo vision method, for example, the distance between the photodetector 2000 and the subject can be measured by using two or more cameras to acquire two or more images of the subject 2100 from two or more different viewpoints. Furthermore, the light-emitting device 2001 and the light-detecting device 2002 can be synchronously controlled by the system control unit 2003.

[0322] <17. Application Examples> (Application to Endoscopic Surgical Systems) The technology disclosed herein (this technology) can be applied to various products. For example, the technology disclosed herein may be applied to endoscopic surgical systems.

[0323] Figure 19 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.

[0324] Figure 19 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 a pneumoperitoneum 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.

[0325] 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.

[0326] 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.

[0327] 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.

[0328] 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 an image based on that image signal.

[0329] 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.

[0330] The light source device 11203 is composed 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] Furthermore, the light source device 11203 may be configured to supply light in a predetermined wavelength range corresponding to special light observation. In special light observation, for example, so-called narrow-band imaging is performed, in which a predetermined tissue such as blood vessels on the surface of the mucosa is imaged with high contrast by irradiating with narrow-band light compared to the irradiation light used in normal observation (i.e., white light), utilizing the wavelength dependence of light absorption in body tissue. Alternatively, fluorescence observation may be performed in special light observation, in which an image is obtained from fluorescence generated by irradiation with excitation light. In fluorescence observation, fluorescence can be obtained by irradiating body tissue with excitation light and observing the fluorescence from the body tissue (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into body tissue and irradiating the body tissue with excitation light corresponding to the fluorescence wavelength of the reagent 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.

[0336] Figure 20 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in Figure 19.

[0337] 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.

[0338] 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.

[0339] 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 configured as a multi-chip type, 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 configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each image sensor.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] 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 is equipped with so-called AE (Auto Exposure), AF (Auto Focus), and AWB (Auto White Balance) functions.

[0345] The camera head control unit 11405 controls the driving of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

[0346] 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.

[0347] 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.

[0348] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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 applied to the imaging unit 11402 of the configuration described above. By applying the technology described herein to the imaging unit 11402, the detection accuracy is improved.

[0354] While an endoscopic surgical system has been described here as an example, the technology described herein may also be applied to other systems, such as microsurgical systems.

[0355] (Examples of application to mobile devices) The technology disclosed herein can be applied to a variety of products. For example, the technology disclosed herein 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, robots, construction machinery, or agricultural machinery (tractors).

[0356] Figure 21 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.

[0357] The vehicle control system 12000 comprises a plurality of electronic control units connected via a communication network 12001. In the example shown in Figure 21, 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.

[0358] 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.

[0359] 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.

[0360] 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.

[0361] 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.

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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 21, 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.

[0367] Figure 22 shows an example of the installation position of the imaging unit 12031.

[0368] In Figure 22, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0369] 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.

[0370] Figure 22 shows an example of the imaging range 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.

[0371] 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.

[0372] 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, etc., that drives autonomously without driver operation, can be performed.

[0373] 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.

[0374] 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.

[0375] The present disclosure has been described above with reference to the first to eighth embodiments, modifications 1 to 14, and application examples. However, the present technology is not limited to the above embodiments, and various modifications are possible. For example, the configurations of the first to eighth embodiments and modifications 1 to 14 described above can be combined with each other as appropriate.

[0376] Furthermore, the effects described herein are merely examples and are not limited to those described; other effects may also occur.

[0377] Furthermore, this disclosure can also take the following configuration. According to the technology with the following configuration, the intrusion of moisture into the organic layer is reduced, and misalignment of the light guide portion caused by the lamination of the organic layer and the inorganic layer is prevented. Therefore, reliability can be improved. (1) A light detection device comprising: a semiconductor substrate having opposing first and second surfaces and having a photoelectric conversion portion for each pixel; a light guide portion provided on the first surface side of the semiconductor substrate and comprising a plurality of structures, each having a size less than or equal to the wavelength of incident light, and provided to fill the space between adjacent plurality of structures, and comprising a medium having a refractive index different from that of the plurality of structures; a spacer layer comprising an organic layer and an inorganic layer laminated in order from the semiconductor substrate side between the semiconductor substrate and the light guide portion; a separation groove provided so as to surround the plurality of structures in a plan view, separating at least the organic layer and exposing the semiconductor substrate on its bottom surface; and a protective film extending at least to the side surface and the bottom surface of the separation groove. (2) The photodetector according to (1), wherein the semiconductor substrate is excavated by the separation groove to a depth of 0.01 μm or more and 10 μm or less from the first surface side. (3) The photodetector according to (1) or (2), wherein the separation groove is embedded by the protective film. (4) The photodetector according to (3), wherein the protective film has voids inside. (5) The photodetector according to (3) or (4), wherein the material of the protective film contains the same material as the medium. (6) The photodetector according to any one of (3) to (5), wherein the arithmetic mean roughness (Ra) of the surface of the protective film above the separation groove is 0.5 or less. (7) The photodetector according to any one of (1) to (6), wherein the separation groove further separates the inorganic layer together with the organic layer. (8) The light detection device according to (7), further comprising a first anti-reflective film between the spacer layer and the light guide portion, wherein the first anti-reflective film extends to the side surface and the bottom surface of the separation groove, and the medium is embedded in the separation groove with the first anti-reflective film in between as the protective film.(9) The light guide portion has a first light guide portion and a second light guide portion stacked in order from the semiconductor substrate side, and further has a second anti-reflective film between the first light guide portion and the second light guide portion, as described in (8). (10) The light guide portion has a first light guide portion and a second light guide portion that are stacked in order from the semiconductor substrate side and each includes the plurality of structures and the medium, and the medium of the first light guide portion is embedded in the separation groove as the protective film, as described in any one of (7) to (9). (11) The light detection device according to any one of (3) to (10), wherein the material of the protective film includes the same material as the inorganic layer. (12) The light detection device according to any one of (3) to (11), wherein the protective film is formed of the inorganic layer. (13) The light detection device according to (12), wherein the protective film is a single layer. (14) The photodetector according to any one of (1) to (13), wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, the plurality of structures are provided in the pixel array portion, and the separation groove is provided in the peripheral portion. (15) The photodetector according to any one of (1) to (14), wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, the plurality of structures are provided in the pixel array portion, and the separation groove comprises a first separation groove provided in the pixel array portion and a second separation groove provided in the peripheral portion. (16) The photodetector according to (14) or (15), further comprising a color filter between the semiconductor substrate and the spacer layer, the color filter extending across the pixel array portion and the peripheral portion. (17) The photodetector according to (16), wherein the separation groove further separates the color filter. (18) The optical detection apparatus according to (16) or (17), wherein the peripheral portion includes an optical black region adjacent to the pixel array portion, and a light-shielding film is further provided between the semiconductor substrate and the color filter in the optical black region.(19) The photodetector according to any one of (1) to (18), wherein the height of the light guide portion is 0.01 μm or more and 2 μm or less. (20) The photodetector according to any one of (1) to (19), wherein the protective film has a thickness of 0.01 μm or more. (21) The photodetector according to any one of (1) to ()), wherein the corners of the organic layer separated by the separation grooves have curvature. (22) The photodetector according to any one of (1) to (21), wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, and the separation groove has one or more third separation grooves in the peripheral portion. (23) The photodetector according to (22), wherein the one or more third separation grooves are provided at the edge of the semiconductor substrate and / or at a pad portion connected to an external electrode or an external circuit in a plan view. (24) The photodetector according to any one of (1) to (23), wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, and the separation groove extends from a pad portion connected to an external electrode or external circuit provided in the peripheral portion to the edge of the semiconductor substrate. (25) The photodetector according to any one of (1) to (24), wherein a plurality of uneven structures are formed on the surface of the semiconductor substrate exposed to the bottom surface of the separation groove. (26) The photodetector according to any one of (1) to (25), wherein the spacer layer further comprises a microlens layer between the organic layer and the inorganic layer, and the microlens layer extends to the side surface and bottom surface of the separation groove. (27) The photodetector according to (26), further comprising a fourth separation groove provided inside the separation groove, wherein the fourth separation groove excavates the semiconductor substrate to a position deeper than the separation groove. (28) The photodetector according to (27), wherein the microlens layer extends to the side and bottom surfaces of the separation groove, and the protective film fills the fourth separation groove.(29) The light detection device according to any one of (26) to (28), wherein the microlens layer is formed using an inorganic material. (30) The light detection device according to any one of (26) to (28), wherein the microlens layer is formed using an organic material. (31) The light detection device according to any one of (16) to (30), wherein the peripheral portion includes an optical black region adjacent to the pixel array portion, and further comprises an embedded layer provided on the light guide portion in the optical black region. (32) A light detection device comprising: a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, wherein a photoelectric conversion portion is provided between a first surface and a second surface facing each of the pixels; a light guide portion provided on the first surface side of the semiconductor substrate and comprising a plurality of structures, each having a size less than or equal to the wavelength of incident light, and provided to fill the space between adjacent plurality of structures, and comprising a medium having a refractive index different from that of the plurality of structures; a spacer layer comprising an organic layer and an inorganic layer stacked sequentially from the semiconductor substrate side between the semiconductor substrate and the light guide portion; and a stepped portion provided between the semiconductor substrate and the spacer layer in the peripheral portion. (33) The light detection device according to (32), further comprising a color filter provided between the semiconductor substrate and the spacer layer in the pixel array portion, wherein the height of the organic layer formed above the stepped portion is equal to the height of the organic layer formed above the color filter. (34) The light detection device according to (32) or (33), wherein the stepped portion is provided continuously or intermittently so as to surround the pixel array portion. (35) The light detection device according to any one of (32) to (34), wherein a plurality of stepped portions are provided extending from the pixel array portion toward the peripheral portion.(36) A photodetector comprising: a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, wherein a photoelectric conversion portion is provided between a first surface and a second surface facing each of the pixels; a light guide portion provided on the first surface side of the semiconductor substrate, each having a size less than or equal to the wavelength of incident light and provided to fill the space between adjacent plurality of structures, containing a medium having a refractive index different from that of the plurality of structures, and having a depression in the peripheral portion; and a embedding layer that fills the depression. (37) The photodetector according to (36), further comprising: a spacer layer including an organic layer and an inorganic layer stacked in order from the semiconductor substrate side between the semiconductor substrate and the light guide portion, and a separation groove provided so as to surround the plurality of structures in a plan view and further having a separation groove for separating at least the organic layer. (38) The photodetector according to (37), wherein the embedding layer is provided above the separation groove. (39) The optical detection device according to (37) or (38), wherein the peripheral portion includes an optical black region adjacent to the pixel array portion, and the separation groove is provided in the optical black region. (40) The optical detection device according to any one of (36) to (39), wherein the embedding layer is formed using a material having a refractive index difference of ±0.3 or less with respect to the medium. (41) The optical detection device according to any one of (36) to (39), wherein the embedding layer includes a dye material.

[0378] This application claims priority based on Japanese Patent Application No. 2025-017281, filed with the Japan Patent Office on 5 February 2025, and all contents of that application are incorporated herein by reference.

[0379] 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 substrate having opposing first and second surfaces and each pixel having a photoelectric conversion unit; a light guide unit provided on the first surface side of the semiconductor substrate and comprising a plurality of structures, each having a size less than or equal to the wavelength of incident light, and provided to fill the spaces between adjacent plurality of structures, and comprising a medium having a refractive index different from that of the plurality of structures; a spacer layer comprising an organic layer and an inorganic layer laminated sequentially from the semiconductor substrate side between the semiconductor substrate and the light guide unit; a separation groove provided so as to surround the plurality of structures in a plan view, separating at least the organic layer and exposing the semiconductor substrate on its bottom surface; and a protective film extending at least to the side surface and bottom surface of the separation groove.

2. The photodetector according to claim 1, wherein the semiconductor substrate is excavated by the separation groove to a depth of 0.01 μm or more and 10 μm or less from the first surface side.

3. The photodetector according to claim 1, wherein the separation groove is embedded by the protective film.

4. The photodetector according to claim 1, wherein the separation groove further separates the inorganic layer together with the organic layer.

5. The light detection device according to claim 4, further comprising a first anti-reflective film between the spacer layer and the light guide portion, wherein the first anti-reflective film extends to the side surface and the bottom surface of the separation groove, and the medium is embedded in the separation groove with the first anti-reflective film in between as the protective film.

6. The light guide portion comprises a first light guide portion and a second light guide portion stacked in order from the semiconductor substrate side, and further comprises a second anti-reflective film between the first light guide portion and the second light guide portion, the light detection device according to claim 5.

7. The light guide portion is stacked sequentially from the semiconductor substrate side and has a first light guide portion and a second light guide portion, each containing the plurality of structures and the medium, and the medium of the first light guide portion is embedded in the separation groove as a protective film, the light detection device according to claim 4.

8. The photodetector according to claim 1, wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, the plurality of structures are provided in the pixel array portion, and the separation groove is provided in the peripheral portion.

9. The photodetector according to claim 1, wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, the plurality of structures are provided in the pixel array portion, and the separation groove comprises a first separation groove provided in the pixel array portion and a second separation groove provided in the peripheral portion.

10. The photodetector according to claim 7, further comprising a color filter between the semiconductor substrate and the spacer layer, wherein the separation groove further separates the color filter.

11. The photodetector according to claim 1, wherein the corners of the organic layer separated by the separation groove have curvature.

12. The photodetector according to claim 1, wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, and the separation groove has one or more third separation grooves in the peripheral portion.

13. The photodetector according to claim 12, wherein the one or more third separation grooves are provided in a plan view at the edge of the semiconductor substrate and / or at the pad portion connected to an external electrode or external circuit.

14. The photodetector according to claim 1, wherein the semiconductor substrate further comprises a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, and the separation groove is provided extending from a pad portion connected to an external electrode or external circuit provided in the peripheral portion to the edge of the semiconductor substrate.

15. The photodetector according to claim 1, wherein a plurality of uneven structures are formed on the surface of the semiconductor substrate exposed to the bottom surface of the separation groove.

16. A photodetector comprising: a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, wherein a photoelectric conversion portion is provided between a first surface and a second surface facing each of the pixels; a light guide portion provided on the first surface side of the semiconductor substrate, each having a size less than or equal to the wavelength of incident light, and provided to fill the space between adjacent plurality of structures, and containing a medium having a refractive index different from that of the plurality of structures; a spacer layer including an organic layer and an inorganic layer stacked sequentially from the semiconductor substrate side between the semiconductor substrate and the light guide portion; and a stepped portion provided between the semiconductor substrate and the spacer layer in the peripheral portion.

17. The photodetector according to claim 16, further comprising a color filter provided between the semiconductor substrate and the spacer layer in the pixel array portion, wherein the height of the organic layer formed above the stepped portion is equal to the height of the organic layer formed above the color filter.

18. The photodetector according to claim 16, wherein the stepped portion is provided continuously or intermittently so as to surround the pixel array portion.

19. The photodetector according to claim 16, wherein a plurality of the stepped portions are provided extending from the pixel array portion toward the peripheral portion.

20. A light detection device comprising: a semiconductor substrate having a pixel array portion in which a plurality of pixels are arranged in an array and a peripheral portion provided around the pixel array portion, wherein a photoelectric conversion portion is provided between a first surface and a second surface facing each of the pixels; a light guide portion provided on the first surface side of the semiconductor substrate, each having a size less than or equal to the wavelength of incident light and provided to fill the space between adjacent plurality of structures, containing a medium having a refractive index different from that of the plurality of structures, and having a depression in the peripheral portion; and a embedding layer that fills the depression.

Images