Light detection device and electronic apparatus

Abstract

A light detection device according to one embodiment of the present disclosure comprises: a semiconductor substrate which has a first surface and a second surface that face each other, on which a plurality of pixels are arranged in a two-dimensional array, and in which a plurality of photoelectric conversion parts each for generating a charge corresponding to the amount of received light by photoelectric conversion are formed to be embedded in each pixel; a plurality of microlenses which are each disposed in each pixel on the first surface side of the semiconductor substrate; a first separation part which is formed to be embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second separation parts which extend from the first separation part toward the center of the pixel in plan view so as to separate the plurality of photoelectric conversion parts adjacent to each other in the pixel up to the middle; and a plurality of scatterers which are provided on the first surface of the semiconductor substrate on a light collection optical path of the microlens in each pixel.

Description

Photodetector and electronic equipment

[0001] The present disclosure relates to, for example, a light detection device and an electronic device capable of acquiring imaging information and parallax information.

[0002] For example, Patent Document 1 discloses a solid-state imaging device in which, in a pixel array section in which a plurality of pixels, each having a plurality of photoelectric conversion elements formed for one on-chip lens, are two-dimensionally arranged, at least one of an inter-pixel isolation section and an inter-pixel light-shielding section formed between the pixels is provided with a protrusion, part of which protrudes in a protruding shape toward the center of the pixel, thereby improving the accuracy of phase difference detection.

[0003] Japanese Patent Application Laid-Open No. 2018-221443

[0004] Incidentally, in a photodetector capable of acquiring imaging information and parallax information, improvements in separation ratio and color mixing are required.

[0005] It would be desirable to provide photodetection devices and electronics that can improve separation ratios and color mixing.

[0006] An optical detection device according to one embodiment of the present disclosure includes a semiconductor substrate having opposing first and second surfaces, in which a plurality of pixels are arranged in a two-dimensional array, and in which a plurality of photoelectric conversion units are embedded for each pixel, the photoelectric conversion units generating an electric charge corresponding to the amount of light received through photoelectric conversion; a plurality of microlenses arranged one for each pixel on the first surface side of the semiconductor substrate; a first separation unit embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second separation units extending from the first separation unit toward the center of the pixel in a planar view so as to separate adjacent photoelectric conversion units partway within the pixel; and a plurality of scatterers provided on the first surface of the semiconductor substrate on the focusing optical path of the microlens for each pixel.

[0007] An electronic device according to one embodiment of the present disclosure includes the photodetector according to the above embodiment.

[0008] In a photodetector and an electronic device according to an embodiment of the present disclosure, a plurality of pixels are arranged in a two-dimensional array on a semiconductor substrate having opposing first and second surfaces. Each of the plurality of pixels includes a plurality of photoelectric conversion units embedded in the semiconductor substrate, and a microlens is disposed on the first surface side. Each pixel is surrounded by a first isolation portion embedded in the semiconductor substrate. Each pixel further includes a plurality of second isolation portions extending from the first isolation portion toward the center of the pixel in a plan view, separating adjacent photoelectric conversion units partway within the pixel. A scatterer is also provided on the first surface of the semiconductor substrate on the light-collecting optical path of the microlens. This suppresses the light confinement effect on the light-collecting optical path and suppresses scattering of incident light by the second isolation portion.

[0009] FIG. 1 is a plan view schematic illustrating an example of the configuration of a unit pixel of a photodetector according to an embodiment of the present disclosure. FIG. 2A is a cross-sectional view schematic of a unit pixel taken along line II' in FIG. 1. FIG. 2B is a cross-sectional view schematic of a unit pixel taken along line II-II' in FIG. 1. A block diagram illustrating the overall configuration of the photodetector shown in FIG. 1. FIG. 4 is an equivalent circuit diagram of the unit pixel shown in FIG. 1. FIG. 5 is a plan view schematic illustrating an example of the configuration of a unit pixel as a comparative example. FIG. 6 is a plan view schematic illustrating an example of the arrangement of color filters in the pixel array section shown in FIG. 3. FIG. 7 is a plan view schematic (A) and a cross-sectional view schematic (B) illustrating an example of the configuration of a unit pixel of a photodetector according to a comparative example. FIG. 8 is a plan view schematic (A) and a cross-sectional view schematic (B) illustrating an example of the configuration of a unit pixel of a photodetector according to a first modification of the present disclosure. FIG. 9 is a plan view schematic (A) and a cross-sectional view schematic (B) illustrating an example of the configuration of a unit pixel of a photodetector according to a second modification of the present disclosure. FIG. 10 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating another example of the configuration of a unit pixel of a photodetector device according to Modification 2 of the present disclosure. FIG. 11 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating an example of the configuration of a unit pixel of a photodetector device according to Modification 3 of the present disclosure. FIG. 12 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating another example of the configuration of a unit pixel of a photodetector device according to Modification 3 of the present disclosure. FIG. 13 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating an example of the configuration of a unit pixel of a photodetector device according to Modification 4 of the present disclosure. FIG. 14 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating another example of the configuration of a unit pixel of a photodetector device according to Modification 4 of the present disclosure. FIG. 15 is a schematic plan view illustrating an example of the configuration of a unit pixel of a photodetector device according to Modification 5 of the present disclosure. FIG. 16 is a schematic plan view illustrating another example of the configuration of a unit pixel of a photodetector device according to Modification 5 of the present disclosure. Fig. 17 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating an example of the configuration of a unit pixel of a photodetector according to Modification 6 of the present disclosure. Fig. 18 is a schematic plan view (A) and a schematic cross-sectional view (B) illustrating an example of the configuration of a unit pixel of a photodetector according to Modification 7 of the present disclosure. Fig. 19 is a schematic plan view illustrating another example of the configuration of a unit pixel of a photodetector according to Modification 7 of the present disclosure. Fig. 20 is a schematic plan view illustrating another example of the configuration of a unit pixel of a photodetector according to Modification 7 of the present disclosure.FIG. 21 is a plan view schematic illustrating an example of the layout of high refractive index portions in a pixel array section of a photodetector according to Modification 8 of the present disclosure. FIG. 22 is a plan view illustrating an example of the shape of a scatterer at each position in a pixel array section of a photodetector according to Modification 9 of the present disclosure. FIG. 23A is a plan view schematic illustrating an example of the shape of a scatterer at position A shown in FIG. 22. FIG. 23B is a plan view schematic illustrating an example of the shape of a scatterer at position B shown in FIG. 22. FIG. 23C is a plan view schematic illustrating an example of the shape of a scatterer at position C shown in FIG. 22. FIG. 24 is a plan view schematic illustrating an example of the arrangement of scatterers in a pixel array section of a photodetector according to Modification 10 of the present disclosure. FIG. 25 is a plan view schematic illustrating an example of the configuration of a unit pixel of a photodetector according to another modification of the present disclosure. FIG. 26 is a plan view schematic illustrating an example of the configuration of a unit pixel of a photodetector according to another modification of the present disclosure. FIG. 27 is a cross-sectional view schematic illustrating an example of the configuration of a unit pixel of a photodetector according to another modification of the present disclosure. Fig. 28 is a block diagram showing an example of the configuration of an electronic device having the photodetector shown in Fig. 1 etc. Fig. 29A is a schematic diagram showing an example of the overall configuration of a photodetection system using the photodetector shown in Fig. 3. Fig. 29B is a diagram showing an example of the circuit configuration of the photodetection system shown in Fig. 29A. Fig. 30 is a block diagram showing an example of the general configuration of a vehicle control system. Fig. 31 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit. Fig. 32 is a diagram showing an example of the general configuration of an endoscopic surgery system. Fig. 33 is a block diagram showing an example of the functional configuration of a camera head and a CCU.

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail 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 aspect. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of the components shown in the drawings. The description will be given in the following order. 1. Embodiment (Example of a photodetector in which a scatterer is provided on the light-collecting optical path of an on-chip lens in a unit pixel having multiple photoelectric conversion units per on-chip lens) 2. Modifications 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) 2-8. Modification 8 (Another Example of the Configuration of the Photodetector) 2-9. 2-10. Modification 9 (another example of the configuration of the photodetector) 2-11. Other modifications 3. Application examples 4. Application examples

[0011] 1. Embodiment FIG. 1 schematically illustrates an example of a planar configuration of a unit pixel P constituting a photodetector (photodetector 1) according to an embodiment of the present disclosure. FIG. 2A schematically illustrates a cross-sectional configuration of the unit pixel P shown in FIG. 1 taken along line II'. FIG. 2B schematically illustrates a cross-sectional configuration of the unit pixel P shown in FIG. 1 taken along line II-II'. The photodetector 1 is, for example, a complementary metal oxide semiconductor (CMOS) image sensor used in electronic devices such as digital still cameras and video cameras, and has a pixel section (pixel array section 100A) in which a plurality of pixels (unit pixels P) 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.

[0012] The photodetector 1 has a configuration in which a plurality of pixels (unit pixels P) capable of simultaneously acquiring imaging information and parallax information are arranged in a matrix in a pixel array section 100A. Each unit pixel P has a plurality of photoelectric conversion units 12 embedded in a semiconductor substrate 11, and an on-chip lens 23L on the light incident side S1. The unit pixels P are surrounded by an inter-pixel isolation section 13 that isolates adjacent unit pixels P in the pixel array section 100A. Each unit pixel P is further provided with a plurality of inter-element isolation sections 14 extending from the inter-pixel isolation section 13 toward the center of the pixel in a planar view so as to isolate adjacent photoelectric conversion units 12 partway within the pixel. A scatterer 15 is disposed in the center of the pixel, which is on the light collecting optical path of the on-chip lens 23L.

[0013] Here, the semiconductor substrate 11 corresponds to a specific example of a "semiconductor substrate" according to an embodiment of the present disclosure. The photoelectric conversion unit 12 corresponds to a specific example of a "photoelectric conversion unit" according to an embodiment of the present disclosure. The on-chip lens 23L corresponds to a specific example of a "microlens" according to an embodiment of the present disclosure. The inter-pixel isolation unit 13 corresponds to a specific example of a "first isolation unit" according to an embodiment of the present disclosure. The plurality of inter-element isolation units 14 correspond to a specific example of a "plurality of second isolation units" according to an embodiment of the present disclosure. The scatterer 15 corresponds to a specific example of a "scatterer" according to an embodiment of the present disclosure.

[0014] 3 shows an example of the overall configuration of the photodetector 1. As described above, the photodetector 1 is, for example, a CMOS image sensor used in electronic devices such as digital still cameras and video cameras, and has a pixel array section 100A as an imaging area in which a plurality of unit pixels P are two-dimensionally arranged in a matrix.

[0015] The photodetector 1 captures incident light (image light) from a subject via an optical lens system (not shown), converts the amount of incident light imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal as a pixel signal. The photodetector 1 has a pixel array section 100A as an imaging area on a semiconductor substrate 11, and also has, in a peripheral region of the pixel array 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 input / output terminals 116.

[0016] The pixel array unit 100A has, for example, a plurality of unit pixels P arranged two-dimensionally in a matrix. The plurality of unit pixels P serve as both imaging pixels and image plane phase difference pixels. The imaging pixels photoelectrically convert an object image formed by the imaging lens in a photodiode PD to generate a signal for generating an image. The image plane phase difference pixels divide the pupil region of the imaging lens and photoelectrically convert the object image from the divided pupil region to generate a signal for phase difference detection.

[0017] 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.

[0018] 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 array 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.

[0019] 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 horizontal signal lines 121 and transmitted to the outside of the semiconductor substrate 11 through the horizontal signal lines 121.

[0020] 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.

[0021] The circuit portion consisting of the vertical drive circuit 111, the column signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, and the output circuit 114 may be formed directly on the semiconductor substrate 11, or may be disposed on an external control IC. Furthermore, these circuit portions may be formed on another substrate connected by a cable or the like.

[0022] 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.

[0023] The input / output terminal 116 is used to exchange signals with the outside.

[0024] [Circuit Configuration of Unit Pixel] Fig. 4 shows an example of a readout circuit for the unit pixel P shown in Fig. 1. As shown in Fig. 1, the unit pixel P has four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 arranged in two rows and two columns as the multiple photoelectric conversion units 12. As shown in Fig. 4, the unit pixel P has the four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4, four transfer transistors TR1, TR2, TR3, and TR4, a floating diffusion FD provided for each unit pixel P, a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL.

[0025] The photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 are each a photodiode (PD). The photoelectric conversion unit 12-1 has an anode connected to a ground voltage line and a cathode connected to the source of the transfer transistor TR1. The photoelectric conversion unit 12-2, like the photoelectric conversion unit 12-1, has an anode connected to a ground voltage line and a cathode connected to the source of the transfer transistor TR2. The photoelectric conversion unit 12-3, like the photoelectric conversion unit 12-1, has an anode connected to a ground voltage line and a cathode connected to the source of the transfer transistor TR3. The photoelectric conversion unit 12-4, like the photoelectric conversion unit 12-1, has an anode connected to a ground voltage line and a cathode connected to the source of the transfer transistor TR4.

[0026] The transfer transistor TR1 is connected between the photoelectric conversion unit 12-1 and the floating diffusion FD. The transfer transistor TR2 is connected between the photoelectric conversion unit 12-2 and the floating diffusion FD. The transfer transistor TR3 is connected between the photoelectric conversion unit 12-3 and the floating diffusion FD. The transfer transistor TR4 is connected between the photoelectric conversion unit 12-4 and the floating diffusion FD. A drive signal TRsig is applied to the gate electrodes of the transfer transistors TR1, TR2, TR3, and TR4. When this drive signal TRsig becomes active, the transfer gates of the transfer transistors TR1, TR2, TR3, and TR4 become conductive, and the signal charges accumulated in the photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 are transferred to the floating diffusion FD via the transfer transistors TR1, TR2, TR3, and TR4.

[0027] The floating diffusion FD is connected between the transfer transistors TR1, TR2, TR3, and TR4 and the amplification transistor AMP. The floating diffusion FD converts the signal charges transferred by the transfer transistors TR1, TR2, TR3, and TR4 into voltage signals and outputs the voltage signals to the amplification transistor AMP.

[0028] 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.

[0029] The amplifier transistor AMP has its gate electrode connected to the floating diffusion FD and its drain electrode connected to a power supply, and serves as the input of a readout circuit for a voltage signal held by the floating diffusion FD, a so-called source follower circuit. That is, the amplifier transistor AMP has its source electrode connected to the vertical signal line Lsig via the select transistor SEL, thereby constituting a source follower circuit together with a constant current source connected to one end of the vertical signal line Lsig.

[0030] 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 read signal (pixel signal) output from the amplification transistor AMP is output to the vertical signal line Lsig via the selection transistor SEL.

[0031] In the unit pixel P, for example, the signal charges generated in the photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 are read out. The signal charges read out from the photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 are output to, for example, a phase difference calculation block of an external signal processing unit, thereby obtaining a signal for phase difference autofocus. Furthermore, the signal charges read out from the photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 are added together in the floating diffusion FD, and the resulting sum is output to, for example, an imaging block of an external signal processing unit, thereby obtaining a pixel signal based on the total charge of the photoelectric conversion units 12-1, 12-2, 12-3, and 12-4.

[0032] [Configuration of Unit Pixel] As described above, the photodetector 1 is, for example, a back-illuminated photodetector. The unit pixels P are two-dimensionally arranged in a matrix in the pixel array 100A and each have a configuration in which, for example, a light receiving section 10, a light collecting section 20 provided on a light incident side S1 of the light receiving section 10, and a multilayer wiring layer 30 provided on the side opposite to the light incident side S1 of the light receiving section 10 are stacked.

[0033] 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 (Si) substrate. The photoelectric conversion sections 12 are, for example, PIN (Positive Intrinsic Negative) type photodiodes (PDs), and have pn junctions in predetermined regions of the semiconductor substrate 11. As described above, four photoelectric conversion sections 12-1, 12-2, 12-3, and 12-4 arranged in two rows and two columns are embedded in the unit pixel P.

[0034] The light receiving section 10 further includes an inter-pixel isolation section 13 , an inter-element isolation section 14 , and a scatterer 15 .

[0035] The inter-pixel isolation portions 13 are embedded in the semiconductor substrate 11 so as to surround each of the unit pixels P arranged in a two-dimensional array in the pixel array section 100A. In other words, the inter-pixel isolation portions 13 are embedded in the semiconductor substrate 11 so as to separate adjacent unit pixels P, and are provided in, for example, a lattice pattern in the pixel array section 100A. The inter-pixel isolation portions 13 are intended to electrically isolate 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 in a cross-sectional view. The inter-pixel isolation portions 13 are formed of, for example, silicon oxide (SiO).

[0036] As shown in FIG. 2B , the inter-pixel isolation portion 13 may have an FTI (Full Trench Isolation) structure that penetrates between the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11, or may have an STI (Shallow Trench Isolation) structure in which an opening (trench) is formed in the semiconductor substrate 11 from the first surface 11S1 side and silicon oxide is buried in the trench.

[0037] The multiple inter-element isolation portions 14 extend from the inter-pixel isolation portion 13 toward the center of the pixel in a planar view so as to separate adjacent photoelectric conversion portions 12 within the pixel. In other words, as shown in Fig. 1 , for example, the four inter-element isolation portions 14 each extend from the inter-pixel isolation portion 13 toward the center of the pixel in a planar view so as to separate four photoelectric conversion portions 12 arranged in two rows and two columns in the X-axis direction (row direction) and the Y-axis direction (column direction) within the pixel. The four inter-element isolation portions 14 each extend to just before the center of the pixel, in other words, just before the light-collecting optical path of the on-chip lens 23L, and are independent of one another. The four inter-element isolation portions 14 are intended to electrically isolate four adjacent photoelectric conversion portions 12-1, 12-2, 12-3, and 12-4 within a pixel, and extend, for example, from the first surface 11S1 side toward the second surface 11S2 side of the semiconductor substrate 11 in a cross-sectional view. Each of the multiple inter-element isolation portions 14 is formed integrally with the inter-pixel isolation portion 13, and, like the inter-pixel isolation portion 13, is formed of, for example, silicon oxide (SiO).

[0038] The multiple inter-element isolation portions 14 may have an FTI structure that penetrates between the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11 as shown in FIG. 2A, or may have an STI structure in which an opening (trench) is formed in the semiconductor substrate 11 from the first surface 11S1 side and silicon oxide is buried in the trench.

[0039] The scatterer 15 is intended to suppress the light confinement effect on the light-collecting optical path of the on-chip lens 23L. The scatterer 15 is intended to suppress scattering of light incident on the semiconductor substrate 11 by the multiple inter-element isolation sections 14. The scatterer 15 is embedded in the first surface 11S1 of the semiconductor substrate 11 on the light-collecting optical path of the on-chip lens 23L. As an example, as shown in FIG. 1 , the scatterer 15 is embedded in the center of a pixel where the multiple inter-element isolation sections 14 are not formed. The scatterer 15 is formed, for example, using a material (low refractive index material) having a refractive index lower than that of the semiconductor substrate 11. An example of the low refractive index material is silicon oxide (SiO), which is used for the inter-pixel isolation section 13 and the multiple inter-element isolation sections 14.

[0040] The scatterer 15 has, for example, a substantially square planar shape similar to the unit pixel P. The scatterer 15 is embedded in the first surface 11S1 of the semiconductor substrate 11 with its four vertices rotated by 45° with respect to the four vertices of the unit pixel P. The scatterer 15 has, for example, a quadrangular pyramid shape that is convex toward the second surface 11S2 of the semiconductor substrate 11. In other words, the cross-sectional shape of the scatterer 15 has a substantially triangular shape that widens toward the light incident side S1.

[0041] As described above, the scatterer 15 is formed using a material (low refractive index material) having a lower refractive index than the semiconductor substrate 11. The traveling direction of light L incident on the scatterer 15 is bent due to the difference in refractive index at the interface between the semiconductor substrate 11 and the scatterer 15. For example, a portion of the light L incident on the scatterer 15 from above is refracted by the interface (refractive surface 15S1) between the semiconductor substrate 11 and the scatterer 15 and enters the photoelectric conversion unit 12-1. A portion of the light L incident on the scatterer 15 from above is refracted by the refractive surface 15S2 of the scatterer 15 and enters the photoelectric conversion unit 12-2. A portion of the light L incident on the scatterer 15 from above is refracted by the refractive surface 15S3 of the scatterer 15 and enters the photoelectric conversion unit 12-3. A portion of the light L incident on the scatterer 15 from above is refracted by the refractive surface 15S4 of the scatterer 15 and enters the photoelectric conversion unit 12-4. In addition, for example, among the light incident on the scatterer 15, oblique incident light L ０is refracted by the refractive surface 15S1 of the scatterer 15 and enters the photoelectric conversion unit 12-1. On the other hand, the obliquely incident light L ０ is refracted by the refractive surface 15S2 of the scatterer 15 and enters the photoelectric conversion unit 12-2, and is converted into obliquely incident light L ０ is refracted by the refractive surface 15S3 of the scatterer 15 and enters the photoelectric conversion unit 12-3, and is converted into obliquely incident light L ０ is refracted by the refractive surface 15S4 of the scatterer 15 and enters the photoelectric conversion unit 12-4. This increases the incidence angle dependency for each unit pixel P, improving the separation ratio.

[0042] As shown in FIG. 1 , it is preferable that a portion (for example, four vertices) of the scatterer 15 overlaps with four inter-element isolation sections 14 extending from the inter-pixel isolation section 13 toward the center of the pixel between four adjacent photoelectric conversion sections 12-1, 12-2, 12-3, and 12-4 in a pixel in a plan view. The inter-pixel isolation section 13, the plurality of inter-element isolation sections 14, and the scatterer 15 are all formed of, for example, silicon oxide, which has a lower refractive index than the semiconductor substrate 11. As shown in FIG. 5 , when the scatterer 15 is provided with gaps from each end of the four inter-element isolation sections 14 so that the four vertices of the scatterer 15 do not overlap with the four inter-element isolation sections 14, for example, obliquely incident light L incident on the first surface 11S1 of the semiconductor substrate 11 in the gaps between the inter-element isolation sections 14 and the scatterer 15 is incident on the first surface 11S1 of the semiconductor substrate 11. ０ is scattered at the interface between the semiconductor substrate 11 and the inter-element isolation portion 14. This scattering at the interface between the semiconductor substrate 11 and the inter-element isolation portion 14 causes color mixing. On the other hand, in a structure in which the plurality of inter-element isolation portions 14 and the scatterer 15 partially overlap as shown in FIG. 1 , the plurality of inter-element isolation portions 14 and the scatterer 15 are made of the same material, so the interface between the inter-element isolation portion 14 and the scatterer 15 does not become a scattering source, and the occurrence of color mixing is suppressed.

[0043] The light-collecting section 20 is provided on the light-incident side S1 of the light-receiving section 10, and includes, for example, an inter-pixel light-shielding film 21, a color filter layer 22, and a lens layer 23.

[0044] The inter-pixel light-shielding film 21 is intended to prevent light that is obliquely incident on the color filter layer 22 from leaking into adjacent unit pixels P that detect light of different wavelengths. The inter-pixel light-shielding film 21 is provided on the inter-pixel isolation portion 13, and is formed in the same layout as the inter-pixel isolation portion 13 in plan view, as shown in FIG.

[0045] Examples of materials constituting the inter-pixel light-shielding film 21 include materials having light-shielding properties. Specific examples include tungsten (W), silver (Ag), copper (Cu), titanium (Ti), aluminum (Al), and alloys thereof. Other examples include metal compounds such as TiN. The inter-pixel light-shielding film 21 may be formed as a single layer film or a multilayer film, for example.

[0046] The color filter layer 22 selectively transmits light of a predetermined wavelength. As shown in Fig. 6, the color filter layer 22 has, for example, a red filter 22R that selectively transmits red light (R), a green filter 22G that selectively transmits green light (G), and a blue filter 22B (not shown) that selectively transmits blue light (B). In addition, the color filter layer 22 may have filters that selectively transmit cyan, magenta, and yellow, respectively.

[0047] Each color filter 22R, 22G, and 22B is provided for each unit pixel P. For example, as shown in FIG. 6 , in four unit pixels P arranged in two rows and two columns, two green filters 22G are arranged on a diagonal line, and one red filter 22R and one blue filter 22B are arranged on each orthogonal diagonal line. The unit pixels (red pixel Pr, green pixel Pg, and blue pixel Pb) provided with each color filter detect the corresponding color light. That is, in the pixel array section 100A, the unit pixels (red pixel Pr, green pixel Pg, and blue pixel Pb) that detect red light (R), green light (G), and blue light (B), respectively, are arranged in a Bayer pattern.

[0048] The color filter layer 22 can be formed using, for example, a pigment or a dye. The thickness of the color filter layer 22 may be different for each color, taking into consideration the color reproducibility and sensor sensitivity of the spectral distribution. In black and white pixels, a layer made of a transparent material can be considered as the color filter layer 22. In infrared pixels, a layer made of a material that selectively transmits infrared light can be considered as the color filter layer 22.

[0049] The lens layer 23 is provided, for example, to cover the entire surface of the pixel array unit 100A and has multiple on-chip lenses 23L on its surface. The on-chip lenses 23L focus light incident from above toward the first surface 11S1 of the semiconductor substrate 11, which serves as the light-receiving surface, and are provided for each unit pixel P as shown in FIG. 1 . The lens layer 23 is formed, for example, using a high refractive index material, specifically, an inorganic material such as silicon nitride (SiN). Alternatively, the lens layer 23 may be formed using a high refractive index organic material such as an episulfide resin, a thietane compound, or a resin thereof. The shape of the on-chip lenses 23L is not particularly limited, and various lens shapes, such as a hemispherical shape or a semi-cylindrical shape, can be used.

[0050] The multilayer wiring layer 30 is provided on the opposite side of the light receiving section 10 from the light incident side S1. The multilayer wiring layer 30 has a configuration in which, for example, a plurality of wiring layers 31, 32, and 33, each including a transfer gate 31G, are stacked with an interlayer insulating layer 34 interposed therebetween. In addition to the readout circuit described above, the multilayer wiring layer 30 is also formed with, 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, an input / output terminal 116, and the like.

[0051] 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).

[0052] The interlayer insulating layer 34 is formed of, for example, a single layer film made of one of silicon oxide (SiO), tetraethoxysilane (TEOS), silicon nitride (SiN), silicon oxynitride (SiON), etc., or a laminated film made of two or more of these materials.

[0053] [Operations and Effects] In the photodetector 1 according to the present embodiment, an on-chip lens 23L is disposed for each unit pixel P on the light-receiving surface (first surface 11S1) side of the semiconductor substrate 11, in which a plurality of photoelectric conversion units 12 are embedded in each unit pixel P. The unit pixel P is surrounded by an inter-pixel isolation portion 13 embedded in the semiconductor substrate 11. The unit pixel P is provided with a plurality of inter-element isolation portions 14 extending from the inter-pixel isolation portion 13 toward the center of the pixel in a plan view to just before the center of the pixel, separating the plurality of adjacent photoelectric conversion units 12 within the pixel. Furthermore, a scatterer 15 is embedded in the first surface 11S1 of the semiconductor substrate 11 in a central portion of the pixel where the plurality of inter-element isolation portions 14 are not provided, which is on the light-collecting optical path of the on-chip lens 23L. This suppresses the light confinement effect on the light-collecting optical path of the on-chip lens 23L and also suppresses scattering of incident light by the plurality of inter-element isolation portions 14. This will be described below.

[0054] In recent years, semiconductor imaging devices (photodetectors) with a focus detection function based on a phase difference detection method have become widespread. Photodetectors with a focus detection function based on a phase difference detection method employ a pixel structure in which multiple photoelectric conversion elements are formed directly under a single on-chip lens (OCL).

[0055] For example, in a pixel structure in which two photoelectric conversion elements are provided for one OCL, incident light collected by the OCL is irradiated onto one of the photoelectric conversion regions of the two photoelectric conversion elements depending on the incident angle. Ideally, if the output of one photoelectric conversion element is 100, the output of the other photoelectric conversion element should be 0. However, in reality, a certain amount of output is also produced from the other photoelectric conversion element. If the output from this other photoelectric conversion element becomes too large, this will result in a decrease in the accuracy of phase difference detection. In other words, the two photoelectric conversion elements provided for one OCL are used as a pair for phase difference detection, but if the output of one photoelectric conversion element is mixed with the output of the other photoelectric conversion element, this will lead to a decrease in the accuracy of phase difference detection.

[0056] One possible structure for preventing the output of one photoelectric conversion element from being mixed with the output of the other photoelectric conversion element is a structure in which a physical separator is provided between the two photoelectric conversion elements. However, if a separator is provided between the two photoelectric conversion elements, the separator may interfere with photoelectric conversion in each photoelectric conversion element, resulting in reduced sensitivity, especially when the focal point of the incident light coincides with the separator. Furthermore, there is a concern that the quality of the captured image may be reduced due to deterioration in the spectral characteristics caused by light scattering at the separator.

[0057] In the above-described solid-state imaging device, at least one of the inter-pixel isolation portions and the inter-pixel light-shielding portions formed between pixels is provided with a protrusion portion that protrudes in a protruding shape toward the center of the pixel, thereby improving the accuracy of phase difference detection while suppressing a decrease in sensitivity and an increase in color mixing.

[0058] FIG. 7 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of the solid-state imaging device. (B) of FIG. 7 shows a cross section corresponding to the line III-III′ shown in (A) of FIG. 7. The unit pixel P has a configuration in which, for example, a light receiving section 1010, a light collecting section 1020 provided on the light incident side S1 of the light receiving section 1010, and a multilayer wiring layer 1030 provided on the opposite side of the light incident side S1 of the light receiving section 1010 are stacked. In a pixel structure in which four photoelectric conversion elements 1012-1, 1012-2, 1012-3, and 1012-4 arranged in two rows and two columns are provided for one on-chip lens 1023, and further a protrusion (inter-element isolation section 1014) protruding from an inter-pixel isolation section 1013 formed to surround the unit pixel P toward the center of the pixel is provided, the light confinement effect at the center of the pixel and the oblique incident light L ０ The scattering caused by collision with the inter-pixel separation portion makes it difficult for the incidence angle dependency to appear.

[0059] In contrast to this, in the present embodiment, a scatterer 15 is embedded in the first surface 11S1 of the semiconductor substrate 11 in the center of the pixel, between a plurality of adjacent photoelectric conversion units 12 within the unit, which is on the light-collecting optical path of the on-chip lens 23L provided for each unit pixel P. This suppresses the light-confining effect on the light-collecting optical path of the on-chip lens 23L, thereby increasing the incidence angle dependency of incident light for each unit pixel P. In addition, scattering of incident light caused by collision with a plurality of inter-element isolation units 14 extending from the inter-pixel isolation unit 13 toward the center of the pixel is suppressed.

[0060] As described above, in the photodetector 1 of this embodiment, it is possible to improve the separation ratio and color mixing in the unit pixel P in which a plurality of photoelectric conversion units 12 are provided for one on-chip lens 23L. Therefore, it is possible to provide a photodetector having high phase difference detection accuracy and excellent imaging performance.

[0061] Next, Modifications 1 to 11 and application examples of the present disclosure 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.

[0062] 8A and 8B are schematic diagrams illustrating an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1A) according to a first modification of the present disclosure. Note that (B) of FIG. 8 illustrates a cross section corresponding to the line IV-IV′ shown in (A) of FIG. The photodetector 1A 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 above embodiment.

[0063] In the above embodiment, an example was shown in which the four inter-element isolation portions 14 separating the four photoelectric conversion portions 12 arranged in two rows and two columns within a unit pixel P all have the same length, but this is not limited to this. Of the four inter-element isolation portions 14 separating the four photoelectric conversion portions 12 arranged in two rows and two columns, the lengths of two pairs of inter-element isolation portions 14 facing each other in the X-axis direction or the Y-axis direction may be different from each other. For example, in the photodetector 1A of this modified example, as shown in FIG. 8A , the pair of inter-element isolation portions 14 extending in the Y-axis direction are longer than the pair of inter-element isolation portions 14 extending in the X-axis direction. Furthermore, in the photodetector 1A of this modified example, the two pairs of inter-element isolation portions 14 are provided with scatterers 15A having a diamond-shaped planar shape corresponding to the lengths.

[0064] In this manner, in this modification, the lengths of two pairs of inter-element isolation portions 14 that face each other in the X-axis direction or the Y-axis direction and separate the four photoelectric conversion portions 12 arranged in two rows and two columns in the unit pixel P are different. Even with this configuration, the same effects as those of the above embodiment can be obtained.

[0065] (2-2. Modification 2) Figure 9 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1B) according to modification 2 of the present disclosure. Note that (B) of Figure 9 shows a cross section corresponding to line VV' shown in (A) of Figure 9. The photodetector 1B 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 above embodiment.

[0066] In the above embodiment, an example was shown in which the scatterer 15 had a substantially square planar shape, but the present invention is not limited to this. In the photodetector 1B of this modified example, a scatterer 15B having a substantially circular planar shape is provided. The scatterer 15B has a substantially hemispherical shape that is convex toward the light incident side S1 of the semiconductor substrate 11, and the cross-sectional shape of the scatterer 15B is a substantially semicircular shape that widens toward the light incident side S1, as shown in FIG. 9B .

[0067] FIG. 10 is a schematic diagram illustrating another example of the planar configuration (A) and cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1B) according to Modification 2 of the present disclosure. Note that (B) of FIG. 10 illustrates a cross section corresponding to the V-V′ line illustrated in (A) of FIG. 10 . The planar shape of the scatterer 15B is not limited to this. For example, as in Modification 1, when two pairs of inter-element separators 14 that face each other in the X-axis direction or the Y-axis direction and separate four photoelectric conversion units 12 arranged in two rows and two columns within the unit pixel P have different lengths, the scatterer 15B may have a substantially elliptical planar shape corresponding to the lengths of the two pairs of inter-element separators 14.

[0068] In this way, in this modification, the scatterer 15B having a substantially circular or substantially elliptical planar shape is provided. Even with this configuration, the same effects as those of the above embodiment can be obtained.

[0069] (2-3. Modification 3) Fig. 11 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1C) according to Modification 3 of the present disclosure. Note that Fig. 11B shows a cross section corresponding to line VI-VI' shown in Fig. 11A. The photodetector 1C 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 above embodiment.

[0070] There is no limitation on the depth to which the scatterer 15 is embedded in the first surface 11S1 of the semiconductor substrate 11. In the photodetector 1C of this modified example, a quadrangular pyramid-shaped scatterer 15C is provided that extends to the vicinity of the second surface 11S2 of the semiconductor substrate 11.

[0071] FIG. 12 is a schematic diagram illustrating another example of the planar configuration (A) and cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1C) according to Modification 3 of the present disclosure. Note that (B) of FIG. 12 illustrates a cross section corresponding to the line VI-VI′ shown in (A) of FIG. 12 . This configuration can be combined with, for example, Modification 1. That is, the lengths of two pairs of inter-element isolation sections 14 facing each other in the X-axis direction or the Y-axis direction, which separate the four photoelectric conversion sections 12 arranged in two rows and two columns within the unit pixel P, may be different from each other, as in Modification 1. Accordingly, the planar shape of the scatterer 15C may be approximately diamond-shaped. Additionally, this configuration can be combined with, for example, Modification 2. That is, the scatterer 15C may have a substantially circular or approximately elliptical planar shape and a conical shape extending to the vicinity of the second surface 11S2 of the semiconductor substrate 11, as in Modification 2.

[0072] In this manner, in this modification, the scatterer 15C extending to the vicinity of the second surface 11S2 of the semiconductor substrate 11 is provided in the central portion of the pixel where the plurality of inter-element isolation portions 14 are not formed. This makes it possible to further suppress the light confinement effect on the light-collecting optical path of the on-chip lens 23L.

[0073] (2-4. Modification 4) FIG. 13 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1D) according to Modification 4 of the present disclosure. Note that (B) of FIG. 13 shows a cross section corresponding to the line VII-VII′ shown in (A) of FIG. 13. FIG. 14 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1D) according to Modification 4 of the present disclosure. Note that (B) of FIG. 14 shows a cross section corresponding to the line VII-VII′ shown in (A) of FIG. 14. The photodetector 1D 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 above-described embodiment.

[0074] In the photodetector 1D of this modification, the scatterer 15 embedded in the first surface 11S1 of the semiconductor substrate 11 in the above embodiment has an extension 15D, e.g., a rectangular prism-shaped extension, extending toward the second surface 11S2 at its apex. The shape of the extension 15D is not limited to this, and it may be cylindrical, for example, in addition to a rectangular prism shape. This configuration can also be combined with Modifications 1 and 2, as shown in FIG. 14 . That is, the planar and cross-sectional shapes of the scatterer 15 embedded near the first surface 11S1 of the semiconductor substrate 11 are not limited. The planar shape of the scatterer 15 may be substantially square, as shown in FIG. 13A , or substantially rhombic, as shown in FIG. 14A . Alternatively, although not shown, the scatterer 15 may be substantially circular or substantially elliptical, as in Modification 2.

[0075] In this manner, in this modification, for example, an extension portion 15D extending toward the second surface 11S2 is provided at the apex of a scatterer (e.g., scatterer 15) having a quadrangular pyramid shape whose bottom surface includes a substantially square shape and a rhombic shape or a cone shape whose bottom surface includes a substantially perfect circle shape and a substantially elliptical shape, for example. This makes it possible to further suppress the light confinement effect on the light-collecting optical path of on-chip lens 23L, as in the above modification 3.

[0076] (2-5. Modification 5) Fig. 15 is a schematic diagram illustrating an example of the planar configuration of a unit pixel P of a photodetector (photodetector 1E) according to Modification 5 of the present disclosure. Fig. 16 is a schematic diagram illustrating another example of the planar configuration of a unit pixel P of a photodetector (photodetector 1E) according to Modification 5 of the present disclosure. The photodetector 1E 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 above-described embodiment.

[0077] In the above embodiment, an example was shown in which a scatterer 15 made of a material (low refractive index material) with a lower refractive index than the semiconductor substrate 11 is embedded in the first surface 11S1 of the semiconductor substrate 11 on the light-collecting optical path of the on-chip lens 23L, but this is not limited thereto. In the photodetector 1E of this modified example, a scatterer 15E formed using a material (high refractive index material) with a higher refractive index than the semiconductor substrate 11 is embedded in the first surface 11S1 of the semiconductor substrate 11 on the light-collecting optical path of the on-chip lens 23L. The planar shape of the scatterer 15E is approximately square as shown in FIG. 15 or rhombic as shown in FIG. 16 . Alternatively, the planar shape of the scatterer 15E may be approximately circular or elliptical, as in Modification 2 (not shown). The cross-sectional shape of the scatterer 15E is approximately triangular or semicircular, widening toward the light-incident side S1, as in the above embodiment.

[0078] In this manner, in this modification, the scatterer 15E made of a material (high refractive index material) having a higher refractive index than the semiconductor substrate 11 is embedded in the first surface 11S1 of the semiconductor substrate 11. In this configuration, the interface with the semiconductor substrate 11, which has a lower refractive index than the scatterer 15E, serves as a refraction surface (scattering source), and therefore the scatterer 15E can relatively reduce the refractive index. Even with this configuration, the same effects as those of the above embodiment can be obtained.

[0079] (2-6. Modification 6) Figure 17 is a schematic diagram showing an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1F) according to Modification 6 of the present disclosure. Note that (B) of Figure 17 shows a cross section corresponding to line VIII-VIII' shown in (A) of Figure 17. The photodetector 1F 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 above-described embodiment.

[0080] In the above embodiment, an example was shown in which the scatterer 15 was embedded in the first surface 11S1 of the semiconductor substrate 11, but this is not limited to this. In the photodetector 1F of this modified example, an intermediate layer 16 is provided on the first surface 11S1 of the semiconductor substrate 11, and a scatterer 15F is embedded in the intermediate layer 16 corresponding to the central portion of a pixel where the plurality of inter-element isolation portions 14 are not formed in a plan view.

[0081] The scatterer 15F is formed using, for example, a material (low refractive index material) having a lower refractive index than the semiconductor substrate 11. An example of a low refractive index material is silicon oxide (SiO), which is used for the inter-pixel isolation portion 13 and the plurality of inter-element isolation portions 14. The scatterer 15F has, for example, a quadrangular pyramid shape that is convex toward the light incident side S1 of the semiconductor substrate 11. In other words, the cross-sectional shape of the scatterer 15F has a substantially triangular shape that widens toward the first surface 11S1 side.

[0082] In the above embodiment, it is preferable that parts of the scatterer 15 (for example, four vertices) overlap with the four inter-element isolation sections 14 in a planar view, but in the photodetector 1F of this modified example, it is expected that the interface (refractive surface) between the semiconductor substrate 11 and the scatterer 15F acts too strongly as a scattering source. Therefore, in this modified example, it is preferable that parts of the scatterer 15F (for example, four vertices) do not overlap with the four inter-element isolation sections 14 in a planar view, and the outer shape of the scatterer 15F is preferably formed inside the ends of the four inter-element isolation sections 14.

[0083] The intermediate layer 16 is formed using, for example, silicon oxide (SiO).

[0084] In this manner, in this modification, the scatterer 15F is formed on the first surface 11S1 of the semiconductor substrate 11 so as to be convex toward the light incident side S1 of the semiconductor substrate 11. This not only achieves the effects of the above embodiment, but also makes it possible to suppress deterioration of device characteristics such as dark current since the semiconductor substrate 11 is not processed.

[0085] (2-7. Modification 7) Figure 18 is a schematic diagram illustrating an example of a planar configuration (A) and a cross-sectional configuration (B) of a unit pixel P of a photodetector (photodetector 1G) according to Modification 7 of the present disclosure. Note that (B) of Figure 18 illustrates a cross section corresponding to line IX-IX' shown in (A) of Figure 18. The photodetector 1G 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 above embodiment.

[0086] In the photodetector 1 G of this modified example, an optical layer 24 is provided between the semiconductor substrate 11 and the inter-pixel light-shielding film 21 and the color filter layer 22 .

[0087] The optical layer 24 guides the light L incident on the on-chip lens 23L to the four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 arranged in two rows and two columns within the unit pixel P before the light L is incident on the semiconductor substrate 11. The optical layer 24 includes a low-refractive index film 24A and a high-refractive index film 24B. The high-refractive index films 24B are provided, for example, above the four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 arranged in two rows and two columns, respectively, and the low-refractive index films 24A are embedded around the high-refractive index films 24B.

[0088] 19 and 20 are schematic diagrams illustrating other examples of the planar layout of the high-refractive-index film 24B. As shown in FIGS. 19 and 20, when a pair of inter-element isolation portions 14 extending in the Y-axis direction are made longer than a pair of inter-element isolation portions 14 extending in the X-axis direction, the high-refractive-index film 24B may be provided so as to straddle the inter-element isolation portions 14 extending between the photoelectric conversion portions 12-1 and 12-4, or between the photoelectric conversion portions 12-2 and 12-3, which are adjacent in the Y-axis direction, as shown in FIG. 19. This can enhance the isolation ratio in the X-axis direction. Alternatively, as shown in FIG. 20, the high-refractive-index film 24B may be provided so as to straddle the inter-element isolation portions 14 extending between the photoelectric conversion portions 12-1 and 12-1, or between the photoelectric conversion portions 12-3 and 12-4, which are adjacent in the X-axis direction. This makes it possible to strengthen the separation ratio in the Y-axis direction.

[0089] The low-refractive-index film 24A, like the scatterer 15, is formed using a material having a refractive index lower than that of the semiconductor substrate 11. The high-refractive-index film 24B, like the scatterer 15E, is formed using a material having a refractive index higher than that of the semiconductor substrate 11.

[0090] As described above, in this modification, an optical layer 24 having a high-refractive index film 24B is provided above four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 arranged in, for example, two rows and two columns between the semiconductor substrate 11 and the inter-pixel light-shielding film 21 and the color filter layer 22. This makes it possible to further suppress the light confinement effect on the light-collecting optical path of the on-chip lens 23L in addition to the effects of the above embodiment.

[0091] (2-8. Modification 8) The high-refractive index film 24B spanning the inter-element isolation portion 14 extending between adjacent photoelectric conversion portions 12 in the X-axis direction or the Y-axis direction described in Modification 7 above may be laid out in accordance with the wavelength to be detected in each unit pixel P. For example, as shown in FIG. 21 , in a green pixel Pg that detects green light (G), the high-refractive index film 24B may be provided so as to span the inter-element isolation portion 14 extending between adjacent photoelectric conversion portions 12 in the Y-axis direction, and in a red pixel Pr that detects red light (R) and a blue pixel Pb that detects blue light (B), the high-refractive index film 24B may be provided so as to span the inter-element isolation portion 14 extending between adjacent photoelectric conversion portions 12 in the X-axis direction.

[0092] (2-9. Modification 9) Fig. 22 is a schematic diagram illustrating the planar configuration of a pixel array unit 100A of a photodetector (for example, the photodetector 1) illustrating Modification 9 of the present disclosure. Figs. 23A to 23C are schematic diagrams illustrating examples of the planar shapes of the scatterer 15 at positions A, B, and C shown in Fig. 22.

[0093] The scatterer 15 provided in each unit pixel P constituting the pixel array section 100A is shaped according to its position (image height) within the pixel array section 100A, as shown in Figures 23A to 23C, so that the deviation in sensitivity difference due to image height can be corrected.

[0094] (2-10. Modification 10) In the above-described embodiments and the like, examples have been shown in which the scatterer 15 is provided in all unit pixels P constituting the pixel array section 100A, but the present invention is not limited to this. The scatterer 15 may be omitted depending on the wavelength to be detected in that unit pixel P. For example, among visible light including red light (R), green light (G), and blue light (B), blue light (B) having a short wavelength is absorbed and not easily scattered by the semiconductor substrate 11 made of Si. Therefore, for example, as shown in FIG. 24 , the scatterer 15 may be provided only in the green pixel Pg that detects green light (G) and the red pixel Pr that detects red light (R), and the scatterer 15 may be omitted in the blue pixel Pb that detects blue light (B).

[0095] Furthermore, the size, shape, and depth of the convexity of the scatterer 15 may be changed depending on the wavelength detected in the unit pixel P.

[0096] (2-11. Other Modifications) Fig. 25 is a schematic diagram showing an example of the planar configuration of a unit pixel P constituting a photodetector (photodetector 1H) according to another modification of the present disclosure. In the above-described embodiment and the like, an example has been shown in which one scatterer 15 is provided for each unit pixel P, but this is not limitative. For example, as shown in Fig. 25, a unit pixel P may be provided with a plurality of scatterers 15H.

[0097] 26 is a schematic diagram illustrating an example of a planar configuration of a unit pixel P constituting a photodetector (photodetector 1I) according to another modification of the present disclosure. In the above-described modification 7, for example, in the unit pixel P, high-refractive-index films 24B are provided above each of four photoelectric conversion units 12-1, 12-2, 12-3, and 12-4 arranged in two rows and two columns, or the high-refractive-index films 24B are provided so as to straddle the inter-element isolation units 14 extending between adjacent photoelectric conversion units 12 in the X-axis direction or the Y-axis direction. However, the present invention is not limited to this. For example, as shown in FIG. 26, the high-refractive-index films 24B may be provided in a frame shape that surrounds the scatterer 15 and straddles the inter-element isolation units 14 extending between adjacent photoelectric conversion units 12 in the X-axis direction and the Y-axis direction.

[0098] 27 is a schematic diagram illustrating an example of a cross-sectional configuration of a unit pixel P constituting a photodetector (photodetector 1J) according to another modified example of the present disclosure. For example, as shown in FIG. 27 , the four inter-element isolation portions 14 that separate four photoelectric conversion units 12 arranged in two rows and two columns may be continuous with each other on the second surface 11S2 side of the semiconductor substrate 11.

[0099] Furthermore, in the above-described modification 9, an example has been shown in which the shape of the scatterer 15 is changed depending on the position (image height) within the pixel array unit 100A, but this is not limiting, and the color filter layer 22 and the on-chip lens 23L arranged for each unit pixel P may also be shifted, for example, toward the optical center of the pixel array unit 100A depending on the position (image height) within the pixel array unit 100A. The shift amounts of the color filter layer 22 and the on-chip lens 23L vary in a substantially concentric pattern from the optical center of the pixel array unit 100A.

[0100] 3. Application Examples Application Example 1 The above-described light detection device 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. 28 shows a schematic configuration of an electronic device 1000.

[0101] 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.

[0102] The lens group 1001 takes in 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 as a pixel signal to the DSP circuit 1002.

[0103] The DSP circuit 1002 is a signal processing circuit that processes signals supplied from the photodetector 1. The DSP circuit 1002 outputs image data obtained by processing the signals 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.

[0104] 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.

[0105] 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.

[0106] 29A is a schematic diagram illustrating an example of the overall configuration of a light detection system 2000 including a light detection device (e.g., the light detection device 1). FIG. 29B is a diagram illustrating 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. The light detection device 2002 may be, for example, the light detection device 1 described above. 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.

[0107] The photodetector 2002 can detect light L1 and light L2. Light L1 is external ambient light reflected by the object (measurement target) 2100 ( FIG. 29A ). Light L2 is light emitted by the light-emitting device 2001 and then reflected by the object 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 object 2100 can be obtained from light L1, and distance information between the object 2100 and the photodetector system 2000 can be obtained from light L2. The photodetector system 2000 can be mounted, for example, on 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, for example, by using the time-of-flight (TOF) of light. 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 photodetector 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 photodetector system 2000 and the subject. The light emitting device 2001 and the light detecting device 2002 can be controlled synchronously by a system control unit 2003 .

[0108] 4. Application Examples (Application Examples to Mobile Bodies) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0109] FIG. 30 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.

[0110] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 30 , 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.

[0111] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0112] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0113] 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.

[0114] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0115] 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.

[0116] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0117] 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.

[0118] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0119] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 30, 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.

[0120] FIG. 31 is a diagram showing an example of the installation position of the imaging unit 12031.

[0121] In FIG. 31 , a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as the imaging unit 12031.

[0122] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The forward images acquired by the imaging units 12101 and 12105 are mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0123] 31 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0124] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0125] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0126] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0127] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0128] The foregoing has described an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 12031 of the above-described configuration. Specifically, the imaging device 100 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 a high-resolution captured image with little noise, thereby enabling high-precision control using the captured image in the mobile object control system.

[0129] (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.

[0130] FIG. 32 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.

[0131] 32 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11153 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0132] 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.

[0133] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0134] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected by the optical system onto the image sensor. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0135] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various types of image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0136] 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.

[0137] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing the surgical site, etc.

[0138] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0139] 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.

[0140] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0141] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0142] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light in a narrower band than the light irradiated during normal observation (i.e., white light) to capture high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, in what is known as narrow band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or may involve locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissues with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0143] FIG. 33 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0144] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0145] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0146] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be a single (so-called single-chip type) or multiple (so-called multi-chip type). When the imaging unit 11402 is composed of a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is composed of a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0152] 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 .

[0153] 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.

[0154] 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.

[0155] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0156] 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.

[0157] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 based on the image signal subjected to image processing by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0158] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0159] In the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0160] The above describes an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied. Of the configurations described above, the technology according to the present disclosure can be suitably applied to the imaging unit 11402 provided in the camera head 11102 of the endoscope 11100. By applying the technology according to the present disclosure to the imaging unit 11402, it is possible to reduce the size or increase the resolution of the imaging unit 11402, thereby providing a compact or high-resolution endoscope 11100.

[0161] The present disclosure has been described above with reference to the embodiments, Modifications 1 to 11, and application examples. However, the present technology is not limited to the above embodiments and various modifications are possible. For example, the components constituting the photodetector (photodetector 1) of the above embodiments may be omitted as appropriate, or other components may be provided. For example, a protective layer or the like that protects the first surface 11S1 of the semiconductor substrate 11 may be provided between the first surface 11S1 of the semiconductor substrate 11 and the inter-pixel light-shielding film 21 and the color filter layer 22. The protective layer may be formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), or the like.

[0162] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0163] The present disclosure may also be configured as follows. According to the present technology configured as follows, the optical confinement effect of incident light on the light-collecting optical path of a microlens is suppressed, and scattering of incident light by a second separation unit that separates adjacent photoelectric conversion units is suppressed. Therefore, it is possible to improve the separation ratio and color mixing. (1) A photodetector comprising: a semiconductor substrate having opposing first and second surfaces, in which a plurality of pixels are arranged in a two-dimensional array, and in which a plurality of photoelectric conversion units that generate charges according to the amount of received light through photoelectric conversion are embedded in each pixel; a plurality of microlenses arranged on the first surface side of the semiconductor substrate, one for each pixel; a first separation unit embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second separation units extending from the first separation unit toward the center of the pixel in a planar view so as to partially separate adjacent photoelectric conversion units within the pixel; and a plurality of scatterers provided on the first surface of the semiconductor substrate on the light-collecting optical path of the microlens, for each pixel. (2) The photodetector according to (1), wherein the plurality of second separation portions are separated from one another before the light-collecting optical path of the microlens. (3) The photodetector according to (1) or (2), wherein the plurality of second separation portions are continuous with one another on the second surface side of the semiconductor substrate. (4) The photodetector according to any one of (1) to (3), wherein the plurality of scatterers each have a symmetrical planar shape in a planar view. (5) The photodetector according to any one of (1) to (4), wherein the plurality of second separation portions include, in a planar view, a pair of second separation portions extending in one direction with the light-collecting optical path of the microlens therebetween and a pair of second separation portions extending in another direction orthogonal to the one direction with the light-collecting optical path of the microlens therebetween, and wherein the pair of second separation portions extending in the one direction and the pair of second separation portions extending in the other direction have different lengths. (6) The optical detection device according to (5), wherein each of the plurality of scattering bodies has an asymmetric planar shape in plan view according to the lengths of a pair of second separation parts extending in the one direction and a pair of second separation parts extending in the other direction.(7) The photodetector according to any one of (1) to (6), wherein the plurality of scatterers are embedded in the first surface of the semiconductor substrate and each have a semicircular, conical, or polygonal pyramidal shape convex toward the second surface. (8) The photodetector according to (7), wherein the plurality of scatterers each have an extension extending from an apex of the conical or polygonal pyramidal shape toward the second surface. (9) The photodetector according to any one of (1) to (6), wherein the plurality of scatterers are provided on the first surface of the semiconductor substrate and each have a conical or polygonal pyramidal shape convex toward the side opposite to the second surface. (10) The photodetector according to any one of (1) to (9), wherein the plurality of scatterers have different planar shapes depending on positions in a pixel array section in which a plurality of pixels are arranged in a two-dimensional array. (11) The photodetector according to (10), wherein a first scatterer provided in a first pixel located at the optical center of the pixel array unit has a symmetrical planar shape, and a second scatterer provided in a second pixel located away from the optical center has a planar shape that is reduced on the optical center side and expanded on the opposite side from the optical center, centered on the light-collecting optical path of the microlens, compared to the first scatterer. (12) The photodetector according to any one of (1) to (11), wherein the scatterer is made of a material having a lower refractive index than the semiconductor substrate. (13) The photodetector according to any one of (1) to (11), wherein the scatterer is made of a material having a higher refractive index than the semiconductor substrate. (14) The photodetector according to any one of (1) to (12), further comprising an optical layer on the first surface of the semiconductor substrate, the optical layer including a high-refractive-index film having a refractive index higher than that of the semiconductor substrate.(15) The photodetector device according to (14), wherein the plurality of second separation sections, in a plan view, have a pair of second separation sections extending in one direction with the focusing optical path of the microlens therebetween, and a pair of second separation sections extending in another direction perpendicular to the one direction with the focusing optical path of the microlens therebetween, and when the one direction is a phase difference acquisition direction and the other direction is a direction other than the phase difference acquisition direction, the high-refractive index film is provided across the plurality of pixels adjacent in the other direction so as to straddle each of the pair of second separation sections extending in the one direction with the pair of second separation sections extending in the other direction therebetween. (16) The photodetector according to any one of (1) to (15), further comprising a color filter layer above the first surface of the semiconductor substrate, the color filter layer including a first color filter, a second color filter, and a third color filter that transmit light of different wavelength bands, the first color filter, the second color filter, and the third color filter being arranged for each pixel, and the shapes of the scatterers provided in the first pixel in which the first color filter is arranged, the second pixel in which the second color filter is arranged, and the third pixel in which the third color filter is arranged are different from each other. (17) The photodetector according to any one of (1) to (16),(18) An electronic device comprising a photodetector, the photodetector comprising: a semiconductor substrate having opposing first and second surfaces, a plurality of pixels arranged in a two-dimensional array, and a plurality of photoelectric conversion units embedded in each pixel, the photoelectric conversion units generating electric charges according to the amount of received light through photoelectric conversion; a plurality of microlenses arranged on the first surface side of the semiconductor substrate, one for each pixel; a first isolation unit embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second isolation units extending from the first isolation unit toward the center of the pixel in a planar view so as to isolate the plurality of photoelectric conversion units adjacent to each other within the pixel; and a plurality of scatterers provided on the first surface of the semiconductor substrate on the light-collecting optical path of the microlens, for each pixel.

[0164] This application claims priority based on Japanese Patent Application No. 2024-018485, filed on February 9, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0165] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A photodetector comprising: a semiconductor substrate having opposing first and second surfaces, a plurality of pixels arranged in a two-dimensional array, and a plurality of photoelectric conversion units embedded in each pixel that generate an electric charge by photoelectric conversion according to the amount of light received; a plurality of microlenses arranged on the first surface side of the semiconductor substrate, one for each pixel; a first isolation unit embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second isolation units extending from the first isolation unit toward the center of the pixel in a planar view so as to isolate adjacent photoelectric conversion units partway within the pixel; and a plurality of scatterers provided on the first surface of the semiconductor substrate on the light-collecting optical path of the microlens, for each pixel.

2. The photodetector according to claim 1, wherein the plurality of second separation sections are separated from each other before the focusing optical path of the microlens.

3. The photodetector according to claim 1, wherein the plurality of second isolation portions are continuous with each other on the second surface side of the semiconductor substrate.

4. The optical detection device according to claim 1, wherein each of the plurality of scatterers has a symmetrical planar shape in a plan view.

5. The optical detection device described in claim 1, wherein the plurality of second separation portions, in a plan view, include a pair of second separation portions extending in one direction with the focusing optical path of the microlens therebetween, and a pair of second separation portions extending in another direction perpendicular to the one direction with the focusing optical path of the microlens therebetween, and the pair of second separation portions extending in the one direction and the pair of second separation portions extending in the other direction have different lengths.

6. An optical detection device as described in claim 5, wherein each of the plurality of scatterers has a planar shape corresponding to the length of a pair of second separation sections extending in the one direction and a pair of second separation sections extending in the other direction when viewed in a plane.

7. The optical detection device according to claim 1, wherein each of the plurality of scatterers is embedded in the first surface of the semiconductor substrate and has a semicircular, conical or polygonal pyramidal shape convex toward the second surface.

8. The optical detection device according to claim 7, wherein each of the plurality of scatterers has an extension portion extending from the apex of the cone shape or the polygonal pyramid shape toward the second surface.

9. The optical detection device according to claim 1, wherein each of the plurality of scatterers is provided on the first surface of the semiconductor substrate and has a conical or polygonal pyramidal shape that is convex toward the side opposite the second surface.

10. The photodetector according to claim 1, wherein the plurality of scatterers have different planar shapes depending on the position of a pixel array section in which a plurality of pixels are arranged in a two-dimensional array.

11. The optical detection device described in claim 10, wherein a first scatterer provided in a first pixel located at the optical center of the pixel array section has a symmetrical planar shape, and a second scatterer provided in a second pixel located away from the optical center has a planar shape that is reduced on the optical center side and expanded on the opposite side of the optical center, centered on the focusing optical path of the microlens, compared to the first scatterer.

12. The photodetector according to claim 1, wherein said scatterer is made of a material having a refractive index lower than that of said semiconductor substrate.

13. The photodetector according to claim 1, wherein the scatterer is made of a material having a refractive index higher than that of the semiconductor substrate.

14. The photodetector device according to claim 1, further comprising an optical layer on the first surface of the semiconductor substrate, the optical layer including a high refractive index film having a refractive index higher than that of the semiconductor substrate.

15. The photodetector device of claim 14, wherein the plurality of second separation sections, in a plan view, have a pair of second separation sections extending in one direction with the focusing optical path of the microlens therebetween, and a pair of second separation sections extending in another direction perpendicular to the one direction with the focusing optical path of the microlens therebetween, and when the one direction is a phase difference acquisition direction and the other direction is a direction other than a phase difference acquisition direction, the high refractive index film is provided across the plurality of pixels adjacent in the other direction so as to straddle each of the pairs of second separation sections extending in the one direction with the pair of second separation sections extending in the other direction therebetween.

16. The photodetector according to claim 1, further comprising a color filter layer above the first surface of the semiconductor substrate, the color filter layer including a first color filter, a second color filter, and a third color filter that transmit light of different wavelength bands, the first color filter, the second color filter, and the third color filter being arranged for each pixel, and the shapes of the scatterers provided in the first pixel in which the first color filter is arranged, the second pixel in which the second color filter is arranged, and the third pixel in which the third color filter is arranged are different from each other.

17. The photodetector according to claim 1, wherein each of the plurality of pixels has four photoelectric conversion units arranged in two rows and two columns as the plurality of photoelectric conversion units.

18. An electronic device comprising a photodetector, the photodetector comprising: a semiconductor substrate having opposing first and second surfaces, a plurality of pixels arranged in a two-dimensional array, and a plurality of photoelectric conversion units embedded in each pixel, the photoelectric conversion units generating electric charges according to the amount of received light through photoelectric conversion; a plurality of microlenses arranged on the first surface side of the semiconductor substrate, one for each pixel; a first isolation unit embedded in the semiconductor substrate so as to surround each of the plurality of pixels; a plurality of second isolation units extending from the first isolation unit toward the center of the pixel in a planar view so as to isolate the plurality of photoelectric conversion units adjacent to each other within the pixel; and a plurality of scatterers provided on the first surface of the semiconductor substrate on the light-collecting optical path of the microlens, for each pixel.

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