Optical detection device

Abstract

To provide an optical detection device capable of improving spectral characteristics.SOLUTION: An optical detection device of an embodiment of the present disclosure comprises: a semiconductor substrate having opposing first and second surfaces, with a plurality of light-receiving portions arranged in an array in an in-plane direction; a plurality of microlenses provided on the first surface side of the semiconductor substrate; and an optical member including a color filter disposed between the first surface of the semiconductor substrate and a plurality of microlenses, and spectrally separating incident light into predetermined wavelengths and a separating portion separating the color filter and consisting of a plurality of layers having differing refractive indices.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light detection device. [Background technology]

[0002] For example, Patent Document 1 discloses a solid-state imaging device in which a waveguide wall portion arranged between color filters and surrounding the periphery of the color filters is formed in multiple stages, and each of the multiple stages of waveguide wall portions is formed at a position where pupil correction is performed, thereby improving pixel sensitivity and preventing color mixing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 220610 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, there is a demand for improved spectral characteristics in photodetectors.

[0005] It would be desirable to provide a photodetector device that allows for improved spectral characteristics.

[0006] An optical detection device according to one embodiment of the present disclosure includes a semiconductor substrate having opposing first and second surfaces and having a plurality of light receiving units arranged in an array in an in-plane direction, a plurality of microlenses provided on the first surface side of the semiconductor substrate, and an optical element provided between the first surface of the semiconductor substrate and the plurality of microlenses, including a color filter that disperses incident light into predetermined wavelengths and a separation section that separates the color filters and is made up of a plurality of layers with different refractive indices.

[0007] In a photodetector according to an embodiment of the present disclosure, a color filter and a separator separating the color filters are provided between a first surface of a semiconductor substrate on which a plurality of light receiving units are arranged in an in-plane array and a plurality of microlenses, and the separator is configured with a plurality of layers with different refractive indices, thereby suppressing scattering of obliquely incident light by the separator. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating another example of the configuration of the photodetector according to the first embodiment of the present disclosure. [Figure 3] FIG. 3 is a block diagram showing the overall configuration of the photodetector shown in FIG. [Figure 4] FIG. 4 is an equivalent circuit diagram of the unit pixel shown in FIG. [Figure 5] FIG. 5 is a schematic plan view for explaining the layout of each position of the pixel section of the separation section shown in FIG. [Figure 6A] FIG. 6A is a diagram illustrating the layout of the separation section at position A shown in FIG. [Figure 6B] FIG. 6B is a diagram illustrating the layout of the separation section at position B shown in FIG. [Figure 6C] FIG. 6C is a diagram illustrating the layout of the separation section at position C shown in FIG. [Figure 6D] FIG. 6D is a diagram illustrating the layout of the separation section at position D shown in FIG. [Figure 6E] FIG. 6E is a diagram illustrating the layout of the separation section at position E shown in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view illustrating another example of the configuration of the photodetector according to the first embodiment of the present disclosure. [Figure 8A] FIG. 8A is a schematic cross-sectional view illustrating a method for manufacturing the photodetector shown in FIG. [Figure 8B] FIG. 8B is a schematic cross-sectional view showing a step subsequent to FIG. 8A. [Figure 8C] FIG. 8C is a schematic cross-sectional view showing a step subsequent to FIG. 8B. [Figure 8D] FIG. 8D is a schematic cross-sectional view showing a step subsequent to FIG. 8C. [Figure 8E] FIG. 8E is a schematic cross-sectional view showing a step subsequent to FIG. 8D. [Figure 8F] FIG. 8F is a schematic cross-sectional view showing a step subsequent to FIG. 8E. [Figure 9] FIG. 9 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to Modification 1 of the present disclosure. [Figure 10] FIG. 10 is a schematic cross-sectional view illustrating another example of the configuration of the photodetector according to the first modification of the present disclosure. [Figure 11A] FIG. 11A is a schematic cross-sectional view illustrating a method for manufacturing the photodetector shown in FIG. [Figure 11B] FIG. 11B is a schematic cross-sectional view showing a step subsequent to FIG. 11A. [Figure 11C] FIG. 11C is a schematic cross-sectional view showing a step subsequent to FIG. 11B. [Figure 11D] FIG. 11D is a schematic cross-sectional view showing a step subsequent to FIG. 11C. [Figure 11E] FIG. 11E is a schematic cross-sectional view showing a step subsequent to FIG. 11D. [Figure 11F] FIG. 11F is a schematic cross-sectional view showing a step subsequent to FIG. 11E. [Figure 11G] FIG. 11G is a schematic cross-sectional view showing a step subsequent to FIG. 11F. [Figure 11H] FIG. 11H is a schematic cross-sectional view showing a step subsequent to FIG. 11G. [Figure 12] FIG. 12 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to Modification 2 of the present disclosure. [Figure 13] FIG. 13 is a cross-sectional view schematically illustrating another example of the configuration of the photodetector according to the second modification of the present disclosure. [Figure 14]FIG. 14 is a cross-sectional view illustrating an example of the configuration of a photodetector according to the third modification of the present disclosure. [Figure 15] FIG. 15 is a cross-sectional view illustrating an example of the configuration of a photodetector according to the fourth modification of the present disclosure. [Figure 16] FIG. 16 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to Modification 5 of the present disclosure. [Figure 17] FIG. 17 is a cross-sectional view schematically illustrating another example of the configuration of a photodetector according to the fifth modification of the present disclosure. [Figure 18] FIG. 18 is a cross-sectional view schematically illustrating another example of the configuration of a photodetector according to the fifth modification of the present disclosure. [Figure 19] FIG. 19 is a cross-sectional view illustrating an example of the configuration of a photodetector according to the sixth modification of the present disclosure. [Figure 20] FIG. 20 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to the seventh modification of the present disclosure. [Figure 21] FIG. 21 is a cross-sectional view illustrating an example of the configuration of a photodetector according to the seventh modification of the present disclosure. [Figure 22] FIG. 22 is a schematic cross-sectional view illustrating an example of the configuration of a photodetector according to the second embodiment of the present disclosure. [Figure 23A] FIG. 23A is a schematic cross-sectional view illustrating a method for manufacturing the photodetector shown in FIG. [Figure 23B] FIG. 23B is a schematic cross-sectional view showing a step subsequent to FIG. 23A. [Figure 23C] FIG. 23C is a schematic cross-sectional view showing a step subsequent to FIG. 23B. [Figure 23D] FIG. 23D is a schematic cross-sectional view showing a step subsequent to FIG. 23C. [Figure 23E] FIG. 23E is a schematic cross-sectional view showing a step subsequent to FIG. 23D. [Figure 23F] FIG. 23F is a schematic cross-sectional view showing a step subsequent to FIG. 23E. [Figure 23G] FIG. 23G is a schematic cross-sectional view showing a step subsequent to FIG. 23F. [Figure 23H]FIG. 23H is a schematic cross-sectional view showing the step subsequent to FIG. 23G. [Figure 23I] FIG. 23I is a schematic cross-sectional view showing a step subsequent to FIG. 23H. [Figure 23J] FIG. 23J is a schematic cross-sectional view showing a step subsequent to FIG. 23I. [Figure 23K] FIG. 23K is a schematic cross-sectional view showing a step subsequent to FIG. 23J. [Figure 23L] FIG. 23L is a schematic cross-sectional view showing the step subsequent to FIG. 23K. [Figure 23M] FIG. 23M is a schematic cross-sectional view showing a step subsequent to FIG. 23L. [Figure 24A] FIG. 24A is a schematic cross-sectional view illustrating a method for manufacturing the photodetector shown in FIG. [Figure 24B] FIG. 24B is a schematic cross-sectional view showing a step subsequent to FIG. 24A. [Figure 24C] FIG. 24C is a schematic cross-sectional view showing a step subsequent to FIG. 24B. [Figure 24D] FIG. 24D is a schematic cross-sectional view showing a step subsequent to FIG. 24C. [Figure 24E] FIG. 24E is a schematic cross-sectional view showing a step subsequent to FIG. 24D. [Figure 24F] FIG. 24F is a schematic cross-sectional view showing a step subsequent to FIG. 24E. [Figure 24G] FIG. 24G is a schematic cross-sectional view showing a step subsequent to FIG. 24F. [Figure 25] FIG. 25 is a block diagram illustrating an example of the configuration of an electronic device having the photodetector shown in FIG. 1 and the like. [Figure 26A] FIG. 26A is a schematic diagram illustrating an example of the overall configuration of a light detection system using the light detection device shown in FIG. 1 and the like. [Figure 26B] FIG. 26B is a diagram illustrating an example of a circuit configuration of the photodetection system illustrated in FIG. 26A. [Figure 27] FIG. 27 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. [Figure 28] FIG. 28 is a block diagram showing an example of the functional configuration of the camera head and the CCU. [Figure 29] FIG. 29 is a block diagram showing an example of a schematic configuration of a vehicle control system. [Figure 30] FIG. 30 is an explanatory diagram showing an example of the installation positions of the outside-of-vehicle information detection unit and the imaging unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described in detail below with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspects. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of each component shown in each drawing. The order of description is as follows. 1. First embodiment (example of photodetector) 2. Variations 2-1. Modification 1 (another example of the configuration of the photodetector) 2-2. Modification 2 (another example of the configuration of the photodetector) 2-3. Modification 3 (another example of the configuration of the photodetector) 2-4. Modification 4 (another example of the configuration of the photodetector) 2-5. Modification 5 (another example of the configuration of the photodetector) 2-6. Modification 6 (another example of the configuration of the photodetector) 2-7. Modification 7 (another example of the configuration of the photodetector) 3. Second embodiment (example of photodetector) 4. Application Examples 5. Application Examples

[0010] <1. First embodiment> 1 and 2 are schematic diagrams illustrating an example of a cross-sectional configuration of a photodetector (photodetector 1) according to a first embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of the overall configuration of the photodetector 1 illustrated in FIGS. 1 and 2. The photodetector 1 is, 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 section (pixel section 100A) in which a plurality of pixels are two-dimensionally arranged in a matrix as an imaging area. The photodetector 1 is, for example, a so-called back-illuminated photodetector in this CMOS image sensor or the like.

[0011] The photodetector 1 has opposing first and second surfaces 11S1 and 11S2. The first surface 11S1 of the semiconductor substrate 11 has a plurality of photoelectric conversion units 12 arranged in an array in the XY plane. The first surface 11S1 has a waveguide unit 22 and a lens layer 23, in this order. The waveguide unit 22 is made up of a plurality of layers (for example, two layers, a first layer 22A and a second layer 22B, or three layers, a first layer 22A, a second layer 22B, and a third layer 22C), and includes color filters 221, 223, and 225, respectively, and separation units 222, 224, and 226 that separate the color filters 221, 223, and 225, respectively. The separation units 222, 224, and 226 are configured to have different refractive indices.

[0012] Here, the semiconductor substrate 11 corresponds to a specific example of a "semiconductor substrate" in an embodiment of the present disclosure. The multiple photoelectric conversion sections 12 correspond to a specific example of a "multiple light receiving sections" in an embodiment of the present disclosure. The waveguide section 22 corresponds to a specific example of an "optical member" in an embodiment of the present disclosure, and the lens layer 23 corresponds to a specific example of a "multiple microlenses" in an embodiment of the present disclosure. The color filters 221, 223, and 225 correspond to a specific example of a "color filter" in an embodiment of the present disclosure, and the separation sections 222, 224, and 226 correspond to a specific example of a "separation section" in an embodiment of the present disclosure.

[0013] [Schematic configuration of the photodetector] The photodetector 1 captures incident light (image light) from a subject via an optical lens system (e.g., a lens group 1001, see FIG. 25), converts the amount of incident light imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the signal as a pixel signal. The photodetector 1 has a pixel section 100A as an imaging area on a semiconductor substrate 11, and also has, in a peripheral region of the pixel section 100A, for example, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and an input / output terminal 116.

[0014] In the pixel section 100A, for example, a plurality of unit pixels P are arranged two-dimensionally in a matrix. The plurality of unit pixels P photoelectrically converts an object image formed by an imaging lens in a photodiode PD to generate a signal for generating an image.

[0015] In the unit pixel P, for example, a pixel drive line Lread (specifically, a row selection line and a reset control line) is wired for each pixel row, and a vertical signal line Lsig is wired for each pixel column. The pixel drive line Lread transmits drive signals for reading signals from the pixels. One end of the pixel drive line Lread is connected to an output terminal of the vertical drive circuit 111 corresponding to each row.

[0016] The vertical drive circuit 111 is a pixel drive unit that includes a shift register, an address decoder, etc., and drives each unit pixel P of the pixel unit 100A, for example, row by row. Signals output from each unit pixel P of a pixel row selected and scanned by the vertical drive circuit 111 are supplied to a column signal processing circuit 112 through each vertical signal line Lsig. The column signal processing circuit 112 is configured with an amplifier, a horizontal selection switch, etc., provided for each vertical signal line Lsig.

[0017] The horizontal drive circuit 113 is configured with a shift register, an address decoder, etc., and scans and sequentially drives each horizontal selection switch of the column signal processing circuit 112. By selective scanning by this horizontal drive circuit 113, signals of each pixel transmitted through each vertical signal line Lsig are output in sequence to a horizontal signal line 121 and transmitted to the outside of the semiconductor substrate 11 through the horizontal signal line 121.

[0018] The output circuit 114 processes and outputs signals sequentially supplied from each of the column signal processing circuits 112 via the horizontal signal line 121. The output circuit 114 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, and the like, for example.

[0019] The circuit portion consisting of the vertical drive circuit 111, column signal processing circuit 112, horizontal drive circuit 113, horizontal signal line 121, and output circuit 114 may be formed directly on the semiconductor substrate 11, or may be disposed in an external control IC. Furthermore, these circuit portions may be formed on another substrate connected by a cable or the like.

[0020] The control circuit 115 receives a clock and data instructing an operation mode from outside the semiconductor substrate 11, and outputs data such as internal information of the photodetector 1. The control circuit 115 further has a timing generator that generates various timing signals, and controls the driving of peripheral circuits such as the vertical drive circuit 111, the column signal processing circuit 112, and the horizontal drive circuit 113 based on the various timing signals generated by the timing generator.

[0021] The input / output terminal 116 is used to exchange signals with the outside.

[0022] [Circuit configuration of unit pixel] Fig. 4 shows an example of a readout circuit of the unit pixel P of the photodetector 1 shown in Fig. 3. As shown in Fig. 4, the unit pixel P includes, for example, one photoelectric conversion unit 12, a transfer transistor TR, a floating diffusion FD, a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL.

[0023] The photoelectric conversion unit 12 is a photodiode (PD). The photoelectric conversion unit 12 has an anode connected to a ground voltage line and a cathode connected to the source of the transfer transistor TR.

[0024] The transfer transistor TR is connected between the photoelectric conversion unit 12 and the floating diffusion FD. A drive signal TRsig is applied to the gate electrode of the transfer transistor TR. When this drive signal TRsig becomes active, the transfer gate of the transfer transistor TR becomes conductive, and the signal charge accumulated in the photoelectric conversion unit 12 is transferred to the floating diffusion FD via the transfer transistor TR.

[0025] The floating diffusion FD is connected between the transfer transistor TR and the amplification transistor AMP. The floating diffusion FD converts the signal charge transferred by the transfer transistor TR into a voltage signal and outputs it to the amplification transistor AMP.

[0026] The reset transistor RST is connected between the floating diffusion FD and the power supply. A drive signal RSTsig is applied to the gate electrode of the reset transistor RST. When this drive signal RSTsig becomes active, the reset gate of the reset transistor RST becomes conductive, and the potential of the floating diffusion FD is reset to the level of the power supply.

[0027] The amplifier transistor AMP has a gate electrode connected to the floating diffusion FD and a drain electrode connected to a power supply, and serves as the input of a readout circuit for the voltage signal held by the floating diffusion FD, a so-called source follower circuit. That is, the amplifier transistor AMP has a source electrode connected to the vertical signal line Lsig via the select transistor SEL, and thereby forms a source follower circuit together with a constant current source connected to one end of the vertical signal line Lsig.

[0028] The selection transistor SEL is connected between the source electrode of the amplification transistor AMP and the vertical signal line Lsig. A drive signal SELsig is applied to the gate electrode of the selection transistor SEL. When this drive signal SELsig is activated, the selection transistor SEL is turned on and the unit pixel P is selected. As a result, a readout signal (pixel signal) output from the amplification transistor AMP is output to the vertical signal line Lsig via the selection transistor SEL.

[0029] [Unit pixel configuration] As described above, the photodetector 1 is, for example, a back-illuminated photodetector, and each of the plurality of unit pixels P arranged two-dimensionally in a matrix in the pixel section 100A has a configuration in which, for example, a light receiving section 10, a light collecting section 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 the light incident side S1 of the light receiving section 10 are stacked.

[0030] The light receiving section 10 includes a semiconductor substrate 11 having a first surface 11S1 and a second surface 11S2 facing each other, and a plurality of photoelectric conversion sections 12 embedded in the semiconductor substrate 11. The semiconductor substrate 11 is made of, for example, a silicon substrate. The photoelectric conversion sections 12 are, for example, PIN (Positive Intrinsic Negative) type photodiodes (PD), and have pn junctions in predetermined regions of the semiconductor substrate 11. The photoelectric conversion sections 12 are embedded in each unit pixel P.

[0031] The light receiving section 10 further includes a pixel separating section 13 .

[0032] The pixel separators 13 are provided between adjacent unit pixels P. In other words, the pixel separators 13 are provided around the unit pixels P and are arranged in a grid pattern in the pixel section 100A. The pixel separators 13 are intended to electrically and optically separate adjacent unit pixels P, and extend, for example, from the first surface 11S1 side of the semiconductor substrate 11 toward the second surface 11S2 side. The pixel separators 13 can be formed, for example, by diffusing p-type impurities.

[0033] Although not shown, a fixed charge film may be further provided on the first surface 11S1 of the semiconductor substrate 11, which also serves as an anti-reflection film on the first surface 11S1 of the semiconductor substrate 11. The fixed charge film is, for example, a film having a negative fixed charge. Examples of materials constituting the fixed charge film include semiconductor materials or conductive materials having a band gap wider than the band gap 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 (TbO x ), 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 The fixed charge film may be a single layer film or a laminated film made of different materials.

[0034] The light-collecting unit 20 is provided on the light-incident side S1 of the light-receiving unit 10, and includes, for example, a protective layer 21, a waveguide unit 22, and a lens layer 23 stacked in this order. The waveguide unit 22 has a multi-layer structure in which multiple layers are stacked. As an example, as shown in FIG. 1, the waveguide unit 22 has a two-layer structure in which a first layer 22A and a second layer 22B are stacked in this order from the first surface 11S1 side of the semiconductor substrate 11. As another example, as shown in FIG. 2, the waveguide unit 22 has a three-layer structure in which a first layer 22A, a second layer 22B, and a third layer 22C are stacked in this order from the first surface 11S1 side of the semiconductor substrate 11.

[0035] The protective layer 21 is intended to reduce deterioration of dark characteristics, and is provided on the first surface 11S1 of the semiconductor substrate 11. By appropriately setting the refractive index and film thickness of the material of the protective layer 21, it is possible to suppress the reflection of light caused by the difference in refractive index between the semiconductor substrate 11 and, for example, the color filter 221. The constituent material of the protective layer 21 is preferably a material with a lower refractive index than the fixed charge film described above, for example, silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ) etc.

[0036] The waveguide 22 has a multi-layer structure as described above. Each layer constituting the waveguide 22 includes a color filter that separates incident light into predetermined wavelengths and a separation portion that separates the color filter into, for example, each unit pixel P. Specifically, in the photodetector 1 shown in FIG. 1, the waveguide 22 has a two-layer structure in which a first layer 22A and a second layer 22B are stacked in this order from the first surface 11S1 side of the semiconductor substrate 11. The first layer 22A includes a color filter 221 and a separation portion 222 that separates the color filter 221 into each unit pixel P. The second layer 22B includes a color filter 223 and a separation portion 224 that separates the color filter 223 into each unit pixel P. In the photodetector 1 shown in Figure 2, the waveguide section 22 has a three-layer structure in which a first layer 22A, a second layer 22B, and a third layer 22C are stacked in this order from the first surface 11S1 side of the semiconductor substrate 11, and the third layer 22C includes a color filter 225 and a separation section 226 that separates the color filter 223 into unit pixels P.

[0037] As described above, the color filters 221, 223, and 225 split incident light into predetermined wavelengths. In other words, the color filters 221, 223, and 225 selectively transmit light of predetermined wavelengths, and each include a green filter that selectively transmits green light (G), a red filter that selectively transmits red light (R), and a blue filter that selectively transmits blue light (B). Alternatively, the color filters 221, 223, and 225 may include filters that selectively transmit cyan, magenta, and yellow, respectively. In the unit pixel P provided with each color filter, for example, the corresponding color light is detected in the respective photoelectric conversion unit 12. The color filters 221, 223, and 225 can be formed using, for example, pigments or dyes. In black-and-white pixels, a layer made of a transparent material can be considered a color filter.

[0038] As described above, the separation portions 222, 224, 226 separate the color filters 221, 223, 225 for each unit pixel P in each of the layers 22A, 22B, 22C. In other words, the separation portions 222, 224, 226 are provided between adjacent unit pixels P in which different color filters are arranged as color filters, and are intended to prevent obliquely incident light from leaking into the adjacently arranged unit pixels P. The separation portions 222, 224, 226 are formed between adjacent unit pixels P in each of the layers 22A, 22B, 22C, and are provided in a grid pattern in the pixel section 100A, for example.

[0039] In this embodiment, the separation sections 222, 224, and 226 in each layer are formed at positions where pupil correction is performed in accordance with the angle of incidence of the incident light L. In other words, the separation sections 222, 224, and 226 in each layer are formed at positions shifted from the boundary between adjacent unit pixels P partitioned by the pixel separation section 13 toward the optical center of the pixel section 100A in accordance with their positions in the pixel section 100A, with the amount of shift increasing in the upper layers.

[0040] 5 is a plan view schematic diagram illustrating the layout of the separation portions 222, 224, and 226 at various positions in the pixel unit 100A. In a unit pixel P provided at position A, which is the optical center of the pixel unit 100A, the separation portions 222, 224, and 226 are formed at approximately the same positions so as to face each other in a plan view, as shown in FIG. 6A. In contrast, in a unit pixel P provided at position B, which is the corner diagonally above and to the left of position A, which is the optical center, the separation portions 222, 224, and 226 are formed so that the amount of shift increases toward the upper layer in a diagonally downward right direction from the outer frame of the unit pixel P toward the optical center, as shown in FIG. 6B. In a unit pixel P provided at position C, which is the corner diagonally above and to the right of position A, which is the optical center, the separation portions 222, 224, and 226 are formed so that the amount of shift increases toward the upper layer in a diagonally downward left direction from the outer frame of the unit pixel P toward the optical center, as shown in FIG. 6C. In a unit pixel P provided at position D, which is the corner diagonally downward to the left with respect to position A, which is the optical center, the separation portions 222, 224, and 226 are formed so that the amount of shift increases toward the upper layer in an upward diagonal direction from the outer frame of the unit pixel P to the optical center, as shown in Fig. 6D. In a unit pixel P provided at position E, which is the corner diagonally downward to the right with respect to position A, which is the optical center, the separation portions 222, 224, and 226 are formed so that the amount of shift increases toward the upper layer in an upward diagonal direction from the outer frame of the unit pixel P to the optical center, as shown in Fig. 6E.

[0041] In this embodiment, the separation portions 222, 224, and 226 of each layer are formed using materials with different refractive indices. For example, in the photodetector 1 shown in FIG. 2, the separation portion 226 provided in the uppermost layer is formed using a material with a lower refractive index than the separation portions 222 and 224. In this case, the separation portions 222 and 224 may be formed using the same material, or may be formed using different materials such that the refractive indices of the separation portions 222, 224, and 226 decrease in order. Alternatively, the separation portion 222 provided in the lowermost layer in the photodetector 1 shown in FIG. 2 may be formed using a material with a lower refractive index than the separation portions 224 and 226. In this case, the separation portions 224 and 226 may be formed using the same material, or may be formed using different materials such that the refractive indices of the separation portions 226, 224, and 222 decrease in order. In this way, the separation section formed using a material with a lower refractive index is not particularly limited, and by forming the separation section of the layer where more light is desired to be concentrated using a material with a lower refractive index and ensuring a refractive index difference with adjacent color filters, it is possible to prevent leakage into adjacent unit pixels P.

[0042] The isolation portions 222, 224, and 226 are made of, for example, silicon oxide (SiO x Among these, the low refractive index material is silicon oxide (SiO x The lowest separating section 222 or, for example, the second lowest separating section 224 can be formed using a metal material with a higher extinction coefficient than the uppermost separating section 226.

[0043] 1 and 2 have been described with reference to an example of a waveguide 22 having a two-layer or three-layer structure, but the number of layers constituting the waveguide 22 is not limited to this. For example, as shown in FIG. 7, the waveguide 22 may be composed of N layers. In this case, too, the separation portions 222, 224, ..., 22n of each layer are formed at positions where pupil correction is performed in accordance with the angle of incidence of the incident light L, and at least one separation portion is formed using a material with a lower refractive index than the separation portions of the other layers. This makes it possible to prevent leakage into adjacent unit pixels P.

[0044] The lens layer 23 is provided, for example, so as to cover the entire surface of the pixel section 100A, and has a plurality of microlenses 23L on its surface. The microlenses 23L are for condensing light incident from above toward the first surface 11S1, which is the light-receiving surface, and are provided for each unit pixel P, for example, as shown in FIG. 1. The lens layer 23 including the microlenses 23L is formed, for example, using a high refractive index material. Specifically, the lens layer 23 is formed, for example, using silicon oxide (SiO x ) and silicon nitride (SiN x ) or other inorganic materials. Alternatively, the lens layer 23 may be formed using an organic material with a high refractive index, such as an episulfide resin, a thietane compound, or a resin thereof. The shape of the microlenses 23L is not particularly limited, and various lens shapes such as a hemispherical shape or a semicylindrical shape can be adopted.

[0045] The multilayer wiring layer 30 is provided on the side opposite to the light incident side S1 of the light receiving unit 10, specifically, on the second surface 11S2 side of the semiconductor substrate 11. The multilayer wiring layer 30 has, for example, a configuration in which a plurality of wiring layers 31, 32, and 33 are stacked with an interlayer insulating layer 34 interposed therebetween. In the multilayer wiring layer 30, for example, in addition to the readout circuit described above, a vertical drive circuit 111, a column signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, an input / output terminal 116, and the like are formed.

[0046] The wiring layers 31, 32, and 33 are formed using, for example, aluminum (Al), copper (Cu), tungsten (W), etc. Alternatively, the wiring layers 31, 32, and 33 may be formed using polysilicon (Poly-Si).

[0047] The interlayer insulating layer 34 is made of, for example, silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiO x N y ) or a laminated film made of two or more of these.

[0048] [Method for manufacturing the waveguide] The waveguide section 22 of the photodetector 1 can be formed, for example, as follows.

[0049] First, as shown in FIG. 8A, separation portions 222 are formed on protective layer 21 by photolithography and etching techniques. At this time, although not shown, a metal film having light-shielding properties may be provided between protective layer 21 and separation portions 222. Alternatively, a passivation film may be formed so as to cover the top and side surfaces of separation portions 222. Next, as shown in FIG. 8B, color filters 221 are formed so as to fill the spaces between separation portions 222, thereby forming first layer 22A.

[0050] Thereafter, second layer 22B and third layer 22C are formed in the same manner as first layer 22A. Specifically, as shown in FIG. 8C, separation portions 224 are formed on first layer 22A by photolithography and etching techniques. Next, as shown in FIG. 8D, color filters 223 are formed to fill the spaces between separation portions 224, thereby forming second layer 22B. Subsequently, as shown in FIG. 8E, separation portions 226 are formed on second layer 22B by photolithography and etching techniques. Next, as shown in FIG. 8F, color filters 225 are formed to fill the spaces between separation portions 226, thereby forming third layer 22C.

[0051] Thereafter, the lens layer 23 having a plurality of microlenses 23L is bonded onto the third layer 22C. In this way, the photodetector 1 shown in FIG.

[0052] In addition, if it is difficult to form the upper layer separation portion 224 (226) due to steps formed between the color filter 221 (223, 225) and the separation portion 222 (224, 226) or due to roughness of the color filter 221 (223, 225), or if an etching stopper film is required when processing the upper layer separation portion 224 (226), a covering layer (for example, covering layer 251 described later) may be provided.

[0053] [Actions and Effects] In the photodetector 1 of this embodiment, a waveguide 22 made up of multiple layers is provided between a first surface 11S1 of a semiconductor substrate 11 on which multiple photoelectric conversion units 12 are arranged in an array in the XY plane and a lens layer 23 including multiple microlenses 23L arranged for each unit pixel P, for example. Each layer (e.g., a first layer 22A and a second layer 22B) constituting the waveguide 22 includes color filters 221 and 223 and separation units 222 and 224 separating the color filters 221 and 223, respectively, and the separation units 222 and 224 are formed using materials with different refractive indices. This suppresses scattering of obliquely incident light L by the separation unit 222 or the separation unit 224. This will be described below.

[0054] In recent years, as pixel sizes have become smaller due to the increased resolution of image sensors, vignetting of obliquely incident light has become an issue. In general image sensors, separation sections are provided to separate the color filters for each pixel in order to increase sensitivity and suppress color mixing, but when obliquely incident light hits these separation sections, it causes a decrease in sensitivity and worsens color mixing.

[0055] In response to this, as mentioned above, a structure has been proposed in which the waveguide wall portion corresponding to the separation portion is formed in multiple stages, and each of the multiple stages of the waveguide wall portion is formed at a position where pupil correction has been performed, thereby preventing obliquely incident light from hitting the separation portion.

[0056] However, when the pixel size becomes smaller, for example, to the wavelength of the incident light or less, simply increasing the number of stages is not enough to narrow down the light due to the diffraction limit, and color mixing occurs due to factors such as the light hitting the separation section, light leaking from the bottom of the separation section into adjacent pixels, and components being guided within the separation section.

[0057] In contrast, in the present embodiment, the waveguide section 22, which is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23 and includes the color filters and the separating section, has a multi-layer structure (two layers: a first layer 22A and a second layer 22B), and the separating sections 222 and 224, which separate the color filters 221 and 223 of the layers 22A and 22B, respectively, are formed using materials with different refractive indices. This suppresses scattering of the obliquely incident light L by the separating section 222 or the separating section 224.

[0058] As a result, the photodetector 1 of this embodiment can improve the spectral characteristics.

[0059] Next, a second embodiment of the present disclosure and modifications 1 to 7 will be described. In the following, the same components as those in the above embodiment will be given the same reference numerals, and the description thereof will be omitted as appropriate.

[0060] <2. Modifications> (2-1. Variation 1) Fig. 9 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector according to Modification 1 of the present disclosure (photodetector 2A). Fig. 10 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 1 of the present disclosure (photodetector 2B). The photodetectors 2A and 2B are, for example, CMOS image sensors used in electronic devices such as digital still cameras and video cameras, and are, for example, so-called back-illuminated photodetectors, similar to the photodetector 1 of the first embodiment.

[0061] In the first embodiment, among the separation portions 222, 224, and 226 of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) that constitute the waveguide portion 22, the separation portions having a low refractive index are made of silicon oxide (SiO x In this modification, a low refractive index is achieved by providing a gap G inside the separating portion.

[0062] 9 shows a configuration in which, of the three layers of the waveguide 24, a first layer 22A, a second layer 22B, and a third layer 24C, the separator 246 of the third layer 24C, which is the uppermost layer, has an internal void G. FIG. 10 shows a configuration in which, of the three layers of the waveguide 24, a first layer 24A, a second layer 22B, and a third layer 22C, the separator 242 of the first layer 24A, which is the lowermost layer, has an internal void G. As in the first embodiment, the separator having an internal void G can be applied to a layer (e.g., the uppermost layer, the lowermost layer, or a layer between them) among the multiple layers constituting the waveguide 24, in which it is desired to further focus the light.

[0063] The separation portion 242 having the void G therein in the first layer 24A can be formed, for example, as follows.

[0064] First, as shown in Fig. 11A, a sacrificial layer 243 is formed on the protective layer 21 by photolithography and etching techniques. Next, as shown in Fig. 11B, a passivation film 242A is formed on the upper and side surfaces of the sacrificial layer 243. Subsequently, as shown in Fig. 11C, a color filter 221 is formed to form a first layer 24A.

[0065] Next, as shown in FIG. 11D, a covering layer 251 is formed on the first layer 24A. Subsequently, as shown in FIG. 11E, a through-hole H penetrating the covering layer 251 and the passivation film 242A is formed on the sacrificial layer 243 by photolithography and etching. Next, as shown in FIG. 11F, the sacrificial layer 243 is removed by etching. This forms a separation portion 242 having a void G therein.

[0066] 11G, a blocking layer 252 that blocks the through-holes H is formed on the covering layer 251. Next, as shown in FIG. 11H, a separation portion 224 is formed on the blocking layer 252 by photolithography and etching techniques. Thereafter, in the same manner as in the first embodiment, a color filter 223 is formed to form a second layer 22B, and further, a separation portion 226 and a color filter 225 are formed in this order on the second layer 22B to form a third layer 22C.

[0067] Thereafter, the lens layer 23 having a plurality of microlenses 23L is bonded onto the third layer 22C. In this way, for example, the photodetector 2B shown in FIG.

[0068] As described above, in this modification, the waveguide section 24 including the color filter and the separator provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23 has a multi-layer structure (for example, three layers), and one of the separators provided in each layer has a low refractive index due to the presence of an internal void G. Even with this configuration, it is possible to obtain the same effects as in the first embodiment.

[0069] (2-2. Variation 2) Fig. 12 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector according to Modification 2 of the present disclosure (photodetector 3A). Fig. 13 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 2 of the present disclosure (photodetector 3B). The photodetectors 3A and 3B are, for example, CMOS image sensors used in electronic devices such as digital still cameras and video cameras, and are, for example, so-called back-illuminated photodetectors, similar to the photodetector 1 of the first embodiment.

[0070] In the first embodiment, among the separation portions 222, 224, and 226 of the plurality of layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) that constitute the waveguide portion 22, the separation portions having a low refractive index are made of silicon oxide (SiO xIn this modification, a low refractive index is achieved by using a metal material having light absorption properties for the separating portion.

[0071] 12 shows a waveguide 26 made up of three layers, a first layer 26A, a second layer 22B, and a third layer 22C, in which a separator 262 in the first layer 26A, the lowest layer, is formed using a light-absorbing metal material. FIG. 13 shows a waveguide 26 made up of three layers, a first layer 22A, a second layer 22B, and a third layer 26C, in which a separator 266 in the third layer 26C, the highest layer, is formed using a light-absorbing metal material. As in the first embodiment, a separator made of a light-absorbing metal material can be applied to a layer (e.g., the top layer, the bottom layer, or a layer between them) in which more light is desired to be focused out of the multiple layers constituting the waveguide 26.

[0072] Examples of metal materials having light absorption properties include tungsten (W), titanium (Ti), and titanium nitride (TiN).

[0073] As described above, in this modification, the waveguide section 26 including the color filter and the separator, which is provided between the first surface 11S1 of the semiconductor substrate 11 and the lens layer 23, has a multi-layer structure (for example, three layers), and one of the separators provided in each layer is made of a metal material having light absorption properties, thereby achieving a low refractive index. This makes it possible to prevent leakage into the adjacent unit pixel P by the separator (for example, separator 262 or separator 264). Therefore, the same effects as those of the first embodiment can be obtained.

[0074] (2-3. Variation 3) 14 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 4) according to Modification 3 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 is, for example, a so-called back-illuminated photodetector, similar to the photodetector 1 of the first embodiment.

[0075] In the first embodiment, the separation sections 222, 224, and 226 of the multiple layers (e.g., the first layer 22A, the second layer 22B, and the third layer 22C) constituting the waveguide section 22 are all formed to have the same width, but this is not limited to this. In this modified example, the widths of the separation sections 222, 224, and 226 are made narrower (w1>w2>w3) in the upper layers.

[0076] In this manner, in this modification, the widths of the separation sections 222, 224, and 226 are made narrower (w1>w2>w3) in the upper layers, which further suppresses scattering of the obliquely incident light L by the separation sections 222, 224, and 226. This makes it possible to further improve the spectral characteristics.

[0077] (2-4. Variation 4) 15 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 5) according to Modification 4 of the present disclosure. The photodetector 5 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, for example, a so-called back-illuminated photodetector similar to the photodetector 1 of the first embodiment.

[0078] In the first embodiment, the multiple layers (e.g., first layer 22A, second layer 22B, and third layer 22C) constituting waveguide portion 22 are all formed to the same thickness, but this is not limited to this. In this modified example, the widths of first layer 22A, second layer 22B, and third layer 22C are formed to be thinner toward the upper layer (h1>h2>h3).

[0079] In this manner, in this modification, the upper layers of the multiple layers (for example, the first layer 22A, the second layer 22B, and the third layer 22C) constituting the waveguide section 22 are formed thinner, which further suppresses scattering of the obliquely incident light L by the separation sections 222, 224, and 226. This makes it possible to further improve the spectral characteristics.

[0080] (2-5. Variation 5) FIG. 16 is a schematic diagram showing an example of a cross-sectional configuration of a photodetector according to Modification 5 of the present disclosure (photodetector 6A). FIG. 17 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 5 of the present disclosure (photodetector 6B). FIG. 18 is a schematic diagram showing another example of a cross-sectional configuration of a photodetector according to Modification 5 of the present disclosure (photodetector 6C). The photodetectors 6A, 6B, and 6C are, for example, CMOS image sensors used in electronic devices such as digital still cameras and video cameras, and are, for example, so-called back-illuminated photodetectors, similar to the photodetector 1 of the first embodiment.

[0081] In the first embodiment, the separators 222, 224, and 226 are provided between all adjacent unit pixels P in which different color filters are arranged, but the present invention is not limited to this. For example, if the color mixing is caused by scattering of light due to shading, some of the separators may be omitted.

[0082] 16 omits part of the separation section 226 in the uppermost third layer 22C of the waveguide section 22, which is made up of three layers, namely, first layer 22A, second layer 22B, and third layer 22C (for example, separation section 226 between red pixel Pr and green pixel Pg adjacent to the light incident side). FIG 17 omits part of the separation section 222 in the lowermost first layer 22A of the waveguide section 22, which is made up of three layers, namely, first layer 22A, second layer 22B, and third layer 22C (for example, separation section 222 between red pixel Pr and blue pixel Pb adjacent to the side opposite to the light incident side).

[0083] Since light with long wavelengths is less likely to be refracted, obliquely incident light is focused at a greater angle.

[0084] For this reason, in this modification, the separation units adjacent to the red pixel Pr that detects red light (R), which has the longest wavelength among red light (R), green light (G), and blue light (B), are appropriately omitted. This makes it possible to reduce scattering of the red light component that hits the separation unit (e.g., separation unit 222 or separation unit 224). This makes it possible to further improve the spectral characteristics.

[0085] 18, the separating portion 224 of the second layer 22B, which has a small contribution to the light-collecting characteristics, is omitted from the waveguide portion 22, which is made up of three layers, the first layer 22A, the second layer 22B, and the third layer 22C.

[0086] In this manner, in this modified example, among the multiple layers (e.g., first layer 22A, second layer 22B, and third layer 22C) constituting the waveguide section 22, the separation section (e.g., separation section 224) that contributes little to the focusing characteristics is omitted, so that in addition to the effects of the first embodiment described above, the manufacturing process can be simplified.

[0087] (2-6. Variation 6) 19 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 7) according to Modification 6 of the present disclosure. The photodetector 7 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and is, for example, a so-called back-illuminated photodetector, similar to the photodetector 1 of the first embodiment.

[0088] Of the multiple layers that make up the waveguide section 27, for example, the separation section 274 of the second layer 27B, which is an intermediate layer, may be configured to have an anti-reflection function.

[0089] The separation portion 274 can be formed, for example, as a laminated film in which an insulating film with a high refractive index and an insulating film with a low refractive index are laminated in this order. The insulating film with a high refractive index can be formed using a material having a refractive index of 1.8 to 2.5, such as silicon nitride (Si3N4), titanium oxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), niobium oxide (Nb2O5), hafnium oxide (HfO2), or aluminum oxide (Al2O3). The insulating film with a low refractive index can be formed using a material such as SiO2, SiON, or SiOC.

[0090] In this way, in this modification, among the multiple layers constituting the waveguide section 27, for example, the second layer 27B, which is an intermediate layer, is provided with the separation section 274 having an anti-reflection function. This makes it possible to enhance the anti-reflection effect on the adjacent color filters 223, thereby enabling further improvement in the spectral characteristics.

[0091] (2-7. Variation 7) FIG. 20 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector according to the seventh modification of the present disclosure (photodetector 1A).

[0092] In the first embodiment described above, an example was shown in which multiple layers (e.g., first layer 22A, second layer 22B, and third layer 22C) constituting the waveguide section 22 were directly stacked, but protective layers 281, 282, and 283 may be provided between the first layer 22A and the second layer 22B, between the second layer 22B and the third layer 22C, and between the third layer 22C and the lens layer 23, respectively.

[0093] FIG. 21 is a schematic diagram showing another example of the cross-sectional configuration of a photodetector according to the seventh modification of the present disclosure (photodetector 1B).

[0094] In the first embodiment, an example in which a color filter and a microlens 23L are provided for each unit pixel P has been shown, but the color filter and the microlens 23L may be formed across a plurality of unit pixels P.

[0095] The photodetector 1B is configured to be able to acquire imaging information and parallax information. The imaging pixels photoelectrically convert the subject image formed by the imaging lens in the photodiodes PD to generate signals for image generation. The image plane phase difference pixels divide the pupil region of the imaging lens, and photoelectrically convert the subject image from the divided pupil regions to generate signals for phase difference detection.

[0096] 3. Second Embodiment 22 is a schematic diagram illustrating an example of a cross-sectional configuration of a photodetector (photodetector 8) according to the second 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 has a pixel section (pixel section 100A) in which a plurality of pixels are two-dimensionally arranged in a matrix as an imaging area. The photodetector 8 is, for example, a so-called back-illuminated photodetector in this CMOS image sensor or the like.

[0097] [Configuration of the photodetector] The photodetector 8 has a first surface 11S1 and a second surface 11S2 facing each other, and a waveguide 42 and a lens layer 23, in this order, on the first surface 11S1 of a semiconductor substrate 11 on which a plurality of photoelectric conversion units 12 are arranged in an array in the XY plane. The waveguide 42 is made up of a plurality of layers (for example, two layers, a first layer 42A and a second layer 42B), and includes color filters 421 and 423 and separation units 422 and 424 that separate the color filters 421 and 423, respectively. Each of the separation units 422 and 424 has a gap G therein.

[0098] [Waveguide manufacturing method 1] The waveguide section 42 of the photodetector 8 can be formed, for example, as follows.

[0099] First, as shown in Fig. 23A, a light-shielding film 44 and a sacrificial layer 425 made of, for example, amorphous silicon are formed in this order on the protective layer 21, and then a resist film 441 is patterned on the sacrificial layer 425 by photolithography. Next, as shown in Fig. 23B, the sacrificial layer 425 and the light-shielding film 44 are processed by etching. Subsequently, as shown in Fig. 23C, a passivation film 422A is formed so as to cover the top and side surfaces of the sacrificial layer 425.

[0100] Next, as shown in Fig. 23D, color filter 421 is deposited to form first layer 42A. Subsequently, as shown in Fig. 23E, covering layer 431 is deposited on first layer 42A. Next, as shown in Fig. 23F, resist film 442 is patterned on covering layer 431 by photolithography.

[0101] 23G, through-holes penetrating coating layer 431 and passivation film 422A are formed on sacrificial layer 425 by etching. Next, as shown in FIG. 23H, sacrificial layer 425 is further formed on coating layer 431, and then resist film 443 is patterned on sacrificial layer 425 by photolithography. Then, as shown in FIG. 23I, sacrificial layer 425 is processed by etching.

[0102] Next, as shown in FIG. 23J, a passivation film 424A is formed to cover the upper and side surfaces of the sacrificial layer 425. Subsequently, as shown in FIG. 23K, a color filter 423 is formed to form the second layer 42B. Next, as shown in FIG. 23L, a coating layer 432 is formed on the second layer 42B, and then a resist film 442 is patterned on the coating layer 432 by photolithography. Subsequently, the sacrificial layer 425 is removed by etching. As a result, a gap G is formed in the separation portions 422, 424 of the first layer 42A and the second layer 42B.

[0103] Thereafter, the lens layer 23 having a plurality of microlenses 23L is bonded onto the third layer 42C. In this way, the photodetector 8 shown in Fig. 20, for example, is completed.

[0104] [Waveguide manufacturing method 2] In the waveguide section 42 of the photodetector 8, the gap G can be formed between each of the layers 42A and 42B, for example, as follows.

[0105] First, as shown in Fig. 24A, similarly to the above-described manufacturing method 2, a resist film 442 is patterned on the covering layer 431 by photolithography. Next, as shown in Fig. 24B, through-holes that penetrate the covering layer 431 and the passivation film 422A are formed on the sacrificial layer 425 by etching, and then the sacrificial layer 425 is removed by etching. As a result, a gap G is formed in the separation portion 422 of the first layer 42A.

[0106] Next, as shown in FIG. 24C, a sacrificial layer 425 is formed on the covering layer 431, and then a resist film 443 is patterned on the sacrificial layer 425 by photolithography. Next, as shown in FIG. 24D, the sacrificial layer 425 is processed by etching, and then a passivation film 424A is formed to cover the upper and side surfaces of the sacrificial layer 425. Next, as shown in FIG. 24E, a color filter 423 is formed to form the second layer 42B. Next, as shown in FIG. 24F, a covering layer 432 is formed on the second layer 42B, and then a resist film 442 is patterned on the covering layer 432 by photolithography. Next, the sacrificial layer 425 is removed by etching. This forms a gap G in the separation portion 424 of the second layer 42B.

[0107] Thereafter, the lens layer 23 having a plurality of microlenses 23L is bonded onto the third layer 42C. In this way, the photodetector 8 shown in Fig. 20, for example, is completed.

[0108] [Actions and Effects] In the photodetector 8 of this embodiment, a waveguide 42 made up of multiple layers is provided between a first surface 11S1 of a semiconductor substrate 11, on which multiple photoelectric conversion units 12 are arranged in an array in the XY plane, and a lens layer 23 including multiple microlenses 23L arranged for each unit pixel P, for example. Each layer (e.g., a first layer 42A and a second layer 42B) constituting the waveguide 42 includes color filters 421 and 423 and separation units 422 and 424 separating the color filters 421 and 423, respectively, and the separation units 422 and 424 have a gap G therein. This increases the difference in refractive index between the color filters 421 and 423 and the separation units 422 and 424.

[0109] As a result, the photodetector 8 of this embodiment can improve its sensitivity.

[0110] <4. Application Examples> (Application example 1) The photodetector 1 and the like can be applied to any type of electronic device with an imaging function, for example, a camera system such as a digital still camera or a video camera, a mobile phone with an imaging function, etc. Fig. 25 shows a schematic configuration of an electronic device 1000.

[0111] The electronic device 1000 includes, for example, a lens group 1001, a photodetector 1, a DSP (Digital Signal Processor) circuit 1002, a frame memory 1003, a display unit 1004, a memory unit 1005, an operation unit 1006, and a power supply unit 1007, which are interconnected via a bus line 1008.

[0112] The lens group 1001 captures incident light (image light) from a subject and forms an image on the imaging surface of the photodetector 1. The photodetector 1 converts the amount of incident light formed on the imaging surface by the lens group 1001 into an electrical signal on a pixel-by-pixel basis and supplies the signal to the DSP circuit 1002 as a pixel signal.

[0113] The DSP circuit 1002 is a signal processing circuit that processes the signal supplied from the photodetector 1. The DSP circuit 1002 outputs image data obtained by processing the signal from the photodetector 1. The frame memory 1003 temporarily stores the image data processed by the DSP circuit 1002 on a frame-by-frame basis.

[0114] The display unit 1004 is composed of a panel-type display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel, and the memory unit 1005 records image data of moving or still images captured by the photodetector 1 on a recording medium such as a semiconductor memory or a hard disk.

[0115] In response to a user's operation, the operation unit 1006 outputs operation signals for various functions of the electronic device 1000. The power supply unit 1007 supplies various types of power to the DSP circuit 1002, frame memory 1003, display unit 1004, storage unit 1005, and operation unit 1006 as needed.

[0116] (Application example 2) FIG. 26A schematically illustrates an example of the overall configuration of a light detection system 2000 including the light detection device 1. FIG. 26B illustrates an example of the circuit configuration of the light detection system 2000. The light detection system 2000 includes a light emitting device 2001 serving as a light source unit that emits infrared light L2, and a light detection device 2002 serving as a light receiving unit having a photoelectric conversion element. The light detection device 1 described above can be used as the light detection device 2002. The light detection system 2000 may further include a system control unit 2003, a light source driving unit 2004, a sensor control unit 2005, a light source side optical system 2006, and a camera side optical system 2007.

[0117] The photodetector 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by a subject (object to be measured) 2100 (FIG. 26A). Light L2 is light 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 can be detected by a photoelectric conversion unit in the photodetector 2002, and light L2 can be detected by a photoelectric conversion region in 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, an electronic device such as a smartphone or a mobile object such as a car. The light-emitting device 2001 can be configured, for example, by a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can be, for example, an iTOF method, but is not limited to this. In the iTOF method, the photoelectric conversion unit can measure the distance to the subject 2100 using, for example, time-of-flight (TOF). The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can also be, for example, a structured light method or a stereo vision method. For example, in the structured light method, a predetermined pattern of light is projected onto the subject 2100 and the distance between the light detection system 2000 and the subject 2100 can be measured by analyzing the distortion of the pattern. In addition, in the stereo vision method, for example, two or more cameras are used to acquire two or more images of the subject 2100 viewed from two or more different viewpoints, thereby measuring the distance between the light detection system 2000 and the subject. The light-emitting device 2001 and the photodetector 2002 can be synchronously controlled by the system control unit 2003.

[0118] <5. Application Examples> (Application example to endoscopic surgery system) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0119] FIG. 27 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0120] 27 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical instruments 11110 such as an insufflation tube 11111 and an energy treatment instrument 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0121] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0122] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens towards an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0123] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0124] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0125] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0126] The light source device 11203 is configured from a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing an operation site or the like.

[0127] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiating light, magnification, focal length, etc.) of the endoscope 11100.

[0128] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0129] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical site can be configured from a white light source configured from, for example, an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, making it possible to adjust the white balance of the captured image in the light source device 11203. In this case, it is also possible to capture images corresponding to each RGB in a time-division manner by irradiating the object of observation with laser light from each RGB laser light source in a time-division manner 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 to the image sensor.

[0130] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free of so-called blocked-up shadows and blown-out highlights.

[0131] The light source device 11203 may also be configured to supply light in a predetermined wavelength range compatible with special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may be performed using fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light compatible with such special light observation.

[0132] FIG. 28 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0133] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so that they can communicate with each other.

[0134] 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 enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0135] The imaging unit 11402 may be configured with one imaging element (a so-called single-plate type) or multiple elements (a so-called multi-plate type). When the imaging unit 11402 is configured with a multi-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured with a plurality of imaging elements (single-plate type) for acquiring image signals for the right eye and left eye corresponding to 3D (dimensional) display. The imaging unit 11402 may be configured to have a pair of imaging elements. 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. If the imaging unit 11402 is configured as a multi-plate type, multiple lens units 11401 may be provided corresponding to the respective imaging elements.

[0136] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately after the objective lens.

[0137] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0138] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0139] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0140] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0141] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0142] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0143] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0144] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data sent from the camera head 11102 .

[0145] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0146] Furthermore, the control unit 11413 causes the display device 11202 to display a captured image showing the surgical site, etc., based on the image signal that has been image processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0147] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0148] In the illustrated example, communication is performed by wire using the transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0149] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the image capturing unit 11402 among the components described above. By applying the technology according to the present disclosure to the image capturing unit 11402, detection accuracy is improved.

[0150] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0151] (Example of application to a moving object) The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

[0152] FIG. 29 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0153] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 29, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0154] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating a braking force of the vehicle, etc.

[0155] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches may be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0156] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc., based on the received images.

[0157] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0158] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0159] The microcomputer 12051 can calculate control target values for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drivetrain control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including avoiding or mitigating collisions between vehicles, following based on the distance between vehicles, maintaining vehicle speed, warning of vehicle collisions, or warning of vehicle lane departure.

[0160] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0161] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information about the outside of the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0162] The audio / video output unit 12052 transmits at least one output signal of audio and / or video to an output device capable of visually or audibly notifying information to passengers in the vehicle or to the outside of the vehicle. In the example of Fig. 29, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0163] FIG. 30 is a diagram showing an example of the installation position of the imaging unit 12031.

[0164] In FIG. 30, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0165] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0166] 30 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

[0167] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0168] For example, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (for example, 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of automatic driving, which runs autonomously without relying on driver operation.

[0169] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drivetrain control unit 12010.

[0170] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the images captured by the image capturing units 12101 to 12104. The pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104, which are infrared cameras, and then performing pattern matching on a series of feature points that indicate the outline of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0171] An example of a mobile object control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 of the above-described configuration. Specifically, the photodetection devices according to the above-described embodiments and their modifications (e.g., photodetection device 1) can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to obtain high-resolution captured images with little noise, thereby enabling high-precision control using the captured images in the mobile object control system.

[0172] Although the present disclosure has been described above with reference to the first and second embodiments, variations 1 to 7, and application examples, the present technology is not limited to the above-described embodiments, etc., and various variations are possible. For example, although variations 1 to 7 have been described above as variations of the first embodiment, the configuration of each variation can be appropriately combined with the second embodiment or other variations.

[0173] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0174] The present disclosure can also be configured as follows: According to the present technology having the following configuration, by configuring the separation section with a plurality of layers having different refractive indices, scattering of obliquely incident light by the separation section is suppressed, thereby making it possible to improve the spectral characteristics. (1) a semiconductor substrate having a first surface and a second surface facing each other and having a plurality of light receiving units arranged in an array in an in-plane direction; a plurality of microlenses provided on the first surface side of the semiconductor substrate; an optical member provided between the first surface of the semiconductor substrate and the plurality of microlenses, the optical member including a color filter that separates incident light into predetermined wavelengths and a separation portion that separates the color filter and is made up of a plurality of layers with different refractive indices; A photodetector comprising: (2) the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector according to (1), wherein the second layer includes a material having a lower refractive index than the color filter layer and the first layer. (3) The optical detection device described in (1) or (2), wherein the separation section includes a first layer, a second layer, and a third layer stacked in order from the first surface side as multiple layers, and the refractive index decreases in the order of the first layer, the second layer, and the third layer. (4) the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device according to any one of (1) to (3), wherein the first layer includes a material having a lower refractive index than the color filter layer and the second layer. (5) The optical detection device described in any one of (1) to (4), wherein the separation portion includes a first layer, a second layer, and a third layer stacked in order from the first surface side as multiple layers, and the refractive index decreases in the order of the third layer, the second layer, and the first layer. (6) the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector according to any one of (1) to (5), wherein the first layer includes a metal material having a higher extinction coefficient than the second layer. (7) The photodetector according to any one of (1) to (6), wherein one of the plurality of layers constituting the separation section has light absorption properties. (8) The photodetector according to any one of (1) to (7), wherein one of the plurality of layers constituting the separation section is made of a void. (9) the separation section includes a first layer and a second layer stacked in order from the first surface side as a plurality of layers, The photodetector according to any one of (1) to (8), wherein the width of the second layer is narrower than the width of the first layer. (10) the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector according to any one of (1) to (9), wherein the first layer and the second layer have different thicknesses. (11) The photodetector according to any one of (1) to (10), wherein the separating section separates the color filter for each of the light receiving sections. (12) The photodetector according to any one of (1) to (11), wherein the color filter is provided continuously across a plurality of light receiving sections. (13) The photodetector according to any one of (1) to (12), wherein the plurality of microlenses are arranged one above each of the plurality of light receiving sections. (14) The photodetector according to any one of (1) to (13), wherein the plurality of microlenses are arranged across the plurality of adjacent light-receiving pixels. (15) The photodetector according to any one of (1) to (14), wherein the plurality of light receiving sections are a plurality of photodiodes embedded in the semiconductor substrate. (16) a semiconductor substrate having a first surface and a second surface facing each other and having a light receiving region in which a plurality of light receiving units are arranged in an array in an in-plane direction; a plurality of microlenses provided on the first surface side of the semiconductor substrate; an optical member including a color filter that is provided between the first surface of the semiconductor substrate and the plurality of microlenses and that separates incident light into predetermined wavelengths, and a separation portion that is made of a plurality of layers that separate the color filters and includes voids; The upper layers of the plurality of layers are shifted toward the center of the light receiving region in accordance with the offset amount of the separation portion with respect to the center of the light receiving region. Light detection device. [Explanation of symbols]

[0175] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 2A, 2B, 3A, 3B, 4, 5, 6A, 6B, 6C, 7, 8...Photodetector device, 10...Light receiving section, 11...Semiconductor substrate, 12...Photoelectric conversion section, 13...Pixel separation section, 20...Light collecting section, 21...Protective layer, 22, 24, 27, 42...Waveguide section, 22A, 24A, 42A...First layer, 22B, 27B, 42B...Second layer , 22C, 24C...third layer, 23...lens layer, 23L...microlens, 30...multilayer wiring layer, 31, 32, 33...wiring layer, 34...interlayer insulating layer, 44...light-shielding film, 221, 223, 335...color filters, 222, 224, 226...separation portion, 11S1...first surface, 11S2...second surface, S1...light incident side, G...gap portion.

Claims

1. a semiconductor substrate having a first surface and a second surface facing each other and having a plurality of light receiving units arranged in an array in an in-plane direction; a plurality of microlenses provided on the first surface side of the semiconductor substrate; an optical member provided between the first surface of the semiconductor substrate and the plurality of microlenses, the optical member including a color filter that separates incident light into predetermined wavelengths and a separation portion that separates the color filter and is made up of a plurality of layers with different refractive indices; A photodetector comprising:

2. the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device according to claim 1 , wherein the second layer includes a material having a lower refractive index than the color filter layer and the first layer.

3. 2. The photodetector device according to claim 1, wherein the separation portion includes a first layer, a second layer, and a third layer stacked in this order from the first surface side as multiple layers, and the refractive indexes of the first layer, the second layer, and the third layer decrease in this order.

4. the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device according to claim 1 , wherein the first layer includes a material having a lower refractive index than the color filter layer and the second layer.

5. 2. The photodetector device according to claim 1, wherein the separation portion includes a first layer, a second layer, and a third layer stacked in this order from the first surface side as multiple layers, and the refractive indexes of the third layer, the second layer, and the first layer decrease in this order.

6. the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device of claim 1 , wherein the first layer comprises a metallic material having a higher extinction coefficient than the second layer.

7. The photodetector according to claim 1 , wherein one of the plurality of layers constituting the separation section has light absorption properties.

8. The photodetector according to claim 1 , wherein one of the plurality of layers constituting the separation section is a void.

9. the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device according to claim 1 , wherein the width of the second layer is narrower than the width of the first layer.

10. the separation section includes a first layer and a second layer stacked in this order from the first surface side as a plurality of layers, The photodetector device of claim 1 , wherein the first layer and the second layer have different thicknesses.

11. The photodetector according to claim 1 , wherein the separating section separates the color filter for each of the light receiving sections.

12. The photodetector according to claim 1 , wherein the color filter is provided continuously across a plurality of light receiving sections.

13. The photodetector according to claim 1 , wherein the plurality of microlenses are disposed one above each of the plurality of light receiving sections.

14. The photodetector device according to claim 1 , wherein the plurality of microlenses are arranged across the plurality of adjacent light-receiving pixels.

15. 2. The photodetector according to claim 1, wherein the plurality of light receiving sections are a plurality of photodiodes embedded in the semiconductor substrate.

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