Photodetector and electronic device

Abstract

A photodetector according to an embodiment of the present disclosure comprises a first photoelectric conversion unit, a second photoelectric conversion unit that is provided adjacent to the first photoelectric conversion unit and has a smaller amount of charge conversion per unit time than the first photoelectric conversion unit, a first lens provided on the upper part of the first photoelectric conversion unit, and a second lens that is provided on the upper part of the second photoelectric conversion unit and is in contact with the first lens, the first lens having a notch on the incident surface for first light that passes through the first lens and is incident in the direction of the second lens.

Description

Photodetector and electronic equipment

[0001] The present disclosure relates to a photodetector and an electronic device including the photodetector.

[0002] For example, Patent Document 1 discloses an imaging device that has two types of photoelectric conversion units that convert different amounts of charge per unit time, and aims to expand the dynamic range by combining the signals acquired by each photoelectric conversion unit.

[0003] JP 2017-163010 A

[0004] Incidentally, in a photodetector in which two types of photoelectric conversion units that convert different amounts of charge per unit time are arranged adjacent to each other, reduction of flare is required.

[0005] Therefore, it is desirable to provide a photodetector and electronic device that can reduce flare while increasing the dynamic range.

[0006] An optical detection device according to one embodiment of the present disclosure includes a first photoelectric conversion unit, a second photoelectric conversion unit that is disposed adjacent to the first photoelectric conversion unit and converts a smaller amount of charge per unit time than the first photoelectric conversion unit, a first lens disposed above the first photoelectric conversion unit, and a second lens disposed above the second photoelectric conversion unit and in contact with the first lens, and the first lens has a notch on the incident surface of first light that passes through the first lens and enters in the direction of the second lens.

[0007] An electronic device according to an embodiment of the present disclosure includes a photodetector, and includes the photodetector according to the embodiment of the present disclosure as the photodetector.

[0008] In the photodetector and the electronic device according to an embodiment of the present disclosure, the first light is refracted by the notch provided on the incident surface of the first light and travels in a direction deviated from the second lens, thereby preventing light obliquely incident on the first lens from leaking into the second photoelectric conversion unit.

[0009] FIG. 1 is a schematic diagram illustrating an example of a planar configuration of a unit pixel of a photodetector according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example of the configuration of a first lens and a second lens illustrated in FIG. 1. FIG. 3 is a block diagram illustrating an example of a functional configuration of a photodetector according to an embodiment of the present disclosure. FIG. 4 is a block diagram illustrating an example of a functional configuration of a photodetector according to a first modified example of an embodiment. FIG. 5 is a block diagram illustrating an example of a functional configuration of a photodetector according to a second modified example of an embodiment. FIG. 6 is a circuit diagram illustrating a circuit configuration of a unit pixel of the photodetector illustrated in FIG. 3 and the like. FIG. 7 is a schematic plan view illustrating an example of a layout of a unit pixel in a pixel array section illustrated in FIG. 3 and the like. FIG. 8 is a schematic cross-sectional view illustrating an example of a configuration of a photodetector taken along line II illustrated in FIG. 7. FIG. 9A is a schematic cross-sectional view illustrating an example of a manufacturing process for the first lens and the second lens illustrated in FIG. 1. FIG. 9B is a schematic cross-sectional view illustrating a process subsequent to FIG. 9A. FIG. 9C is a schematic cross-sectional view illustrating a process subsequent to FIG. 9B. FIG. 9D is a schematic cross-sectional view illustrating a process subsequent to FIG. 9C. 9E is a schematic cross-sectional view illustrating a step subsequent to FIG. 9D . FIG. 9F is a schematic cross-sectional view illustrating a step subsequent to FIG. 9E . FIG. 10A is a schematic diagram illustrating an example of a planar configuration of a first lens and a second lens of a photodetector according to Modification 1 of the present disclosure. FIG. 10B is a perspective view illustrating the configuration of the first lens and the second lens shown in FIG. 10A . FIG. 11A is a schematic diagram illustrating an example of a planar configuration of a first lens and a second lens of a photodetector according to Modification 2 of the present disclosure. FIG. 11B is a perspective view illustrating the configuration of the first lens and the second lens shown in FIG. 11A . FIG. 12A is a schematic diagram illustrating an example of a planar configuration of a first lens and a second lens of a photodetector according to Modification 3 of the present disclosure. FIG. 12B is a perspective view illustrating the configuration of the first lens and the second lens shown in FIG. 12A . FIG. 13 is a schematic diagram illustrating an example of a planar configuration of a first lens and a second lens of a photodetector according to Modification 4 of the present disclosure. Fig. 14 is a schematic diagram showing another example of the planar configuration of the first lens and the second lens of the photodetector according to Modification 4 of the present disclosure. Fig. 15 is a schematic diagram showing another example of the planar configuration of the first lens and the second lens of the photodetector according to Modification 4 of the present disclosure. Fig. 16 is a block diagram showing an example of the configuration of an electronic device using the photodetector shown in Fig. 3 etc.Fig. 17A is a schematic diagram showing an example of the overall configuration of a light detection system using the light detection device shown in Fig. 3 etc. Fig. 17B is a diagram showing an example of the circuit configuration of the light detection system shown in Fig. 17A. Fig. 18 is a diagram showing an example of the general configuration of an endoscopic surgery system. Fig. 19 is a block diagram showing an example of the functional configuration of a camera head and a CCU. Fig. 20 is a block diagram showing an example of the general configuration of a vehicle control system. Fig. 21 is an explanatory diagram showing an example of the installation positions of an outside vehicle information detection unit and an imaging unit.

[0010] An embodiment of the present disclosure will be described in detail below with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspects. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of the components shown in the drawings. The description will be given in the following order. 1. Embodiment (Example of a photodetector provided with a lens having a cutout) 1-1. Overall configuration of the photodetector 1-2. Circuit configuration of a unit pixel 1-3. Configuration of a unit pixel 1-4. Method of manufacturing the first lens and the second lens 1-5. Actions and effects 2. Modifications 2-1. Modification 1 (Another example of a photodetector) 2-2. Modification 2 (Another example of a photodetector) 2-3. Modification 3 (Another example of a photodetector) 2-4. Modification 4 (Another example of a photodetector) 3. Application examples 4. Application examples

[0011] 1. Embodiment Fig. 1 is a schematic diagram illustrating an example of a planar configuration of a unit pixel P of a photodetector 1 according to an embodiment of the present disclosure. Fig. 2 is a perspective view illustrating an example of the configuration of a first lens 241 and a second lens 242 illustrated in Fig. 1. The photodetector 1 captures an image by receiving light from a subject, photoelectrically converting the light, and generating an image signal. The photodetector 1 is, for example, a so-called global shutter back-illuminated image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0012] The photodetector 1 has a pixel array section 111 in which a plurality of unit pixels P are arranged in an array (see, for example, FIG. 3 ). Each of the plurality of unit pixels P has a first pixel section P1 and a second pixel section P2 adjacent to the first pixel section P1. The first pixel section P1 has a first photoelectric conversion section 12A and a first lens 241 provided above the first photoelectric conversion section 12A. The second pixel section P2 has a second photoelectric conversion section 12B that converts a smaller amount of charge per unit time than the first photoelectric conversion section 12A, and a second lens 242 provided above the second photoelectric conversion section 12B. In this embodiment, the first lens 241 has a notch 243 on an incident surface for light (incident light L) that passes through the first lens 241 and enters in the direction of the second lens 242. As a result, incident light L incident in the direction of the second lens 242 is refracted by the cutout portion 243 and deviates from the second lens 242, as shown in FIG.

[0013] Here, the unit pixel P corresponds to a specific example of a "pixel" according to one aspect of the present disclosure. The first photoelectric conversion unit 12A corresponds to a specific example of a "first photoelectric conversion unit" according to one aspect of the present disclosure. The second photoelectric conversion unit 12B corresponds to a specific example of a "second photoelectric conversion unit" according to one aspect of the present disclosure. The first lens 241 corresponds to a specific example of a "first lens" according to one aspect of the present disclosure. The second lens 242 corresponds to a specific example of a "second lens" according to one aspect of the present disclosure. The notch portion 243 corresponds to a specific example of a "notch portion" according to one aspect of the present disclosure. The incident light L corresponds to a specific example of a "first light" according to one aspect of the present disclosure.

[0014] [1-1. Overall Configuration of Photodetection Apparatus] FIG. 3 is a block diagram showing an example of the functional configuration of the photodetection apparatus 1 (photodetection apparatus 1A) according to one embodiment of the present disclosure.

[0015] As described above, the photodetector 1A is a so-called global shutter back-illuminated image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor, etc. The photodetector 1A captures an image by receiving light from a subject, photoelectrically converting the light, and generating an image signal.

[0016] The global shutter method is a method of performing global exposure in which exposure is basically started and ended simultaneously for all pixels. Here, "all pixels" refers to all pixels that appear in an image, excluding dummy pixels and the like. Furthermore, if the time difference and image distortion are small enough to be negligible, the global shutter method also includes a method in which global exposure is performed in units of multiple rows (e.g., several tens of rows) rather than simultaneously for all pixels, while the area in which global exposure is performed is moved. Furthermore, the global shutter method also includes a method in which global exposure is performed on pixels in a predetermined area, rather than on all pixels that appear in an image.

[0017] A back-illuminated image sensor is an image sensor configured such that a photoelectric conversion unit such as a photodiode that receives light from a subject and converts it into an electrical signal is located between a light-receiving surface onto which the light from the subject is incident and a wiring layer on which wiring such as transistors that drive each pixel is provided.

[0018] The photodetector 1A includes, for example, a pixel array section 111, a vertical drive section 112, a column signal processing section 113, a data storage section 119, a horizontal drive section 114, a system control section 115, and a signal processing section 118.

[0019] In the photodetector 1A, a pixel array section 111 in which a plurality of unit pixels P are arranged in an array is formed on a semiconductor substrate 11 (described later). Peripheral circuits such as a vertical drive section 112, a column signal processing section 113, a data storage section 119, a horizontal drive section 114, a system control section 115, and a signal processing section 118 are formed on the same semiconductor substrate 11 as the pixel array section 111, for example.

[0020] The pixel array section 111 has a plurality of unit pixels P, each including a photoelectric conversion section 12 (described later) that generates and accumulates electric charges according to the amount of light incident from a subject. The unit pixels P are arranged in both a horizontal direction (row direction) and a vertical direction (column direction), as shown in FIG. 3 . In the pixel array section 111, a pixel drive line 116 is wired along the row direction for each pixel row made up of unit pixels P arranged in a column in the row direction, and a vertical signal line (VSL) 117 is wired along the column direction for each pixel column made up of unit pixels P arranged in a column in the column direction.

[0021] The vertical drive unit 112 includes a shift register, an address decoder, etc. The vertical drive unit 112 supplies signals, etc. to the plurality of unit pixels P via the plurality of pixel drive lines 116, thereby driving all of the plurality of unit pixels P in the pixel array unit 111 simultaneously or driving them on a pixel row basis.

[0022] The signals output from each unit pixel P in a pixel row selected and scanned by the vertical drive unit 112 are supplied to the column signal processing unit 113 through each VSL 117. The column signal processing unit 113 performs predetermined signal processing on the signals output from each unit pixel in the selected row through the VSL 117 for each pixel column in the pixel array unit 111, and temporarily holds the pixel signals after signal processing.

[0023] Specifically, the column signal processing unit 113 includes, for example, a shift register and an address decoder, and performs noise removal processing, correlated double sampling processing, A / D (Analog / Digital) conversion of analog pixel signals, etc. to generate digital pixel signals. The column signal processing unit 113 supplies the generated pixel signals to the signal processing unit 118.

[0024] The horizontal driving unit 114 is configured with a shift register, an address decoder, etc., and is configured to sequentially select unit circuits corresponding to pixel columns in the column signal processing unit 113. By selective scanning by this horizontal driving unit 114, pixel signals that have been signal-processed for each unit circuit in the column signal processing unit 113 are output sequentially to the signal processing unit 118.

[0025] The system control unit 115 includes a timing generator that generates various timing signals, etc. The system control unit 115 controls the driving of the vertical driving unit 112, the column signal processing unit 113, and the horizontal driving unit 114 based on the timing signals generated by the timing generator.

[0026] The signal processing unit 118 performs signal processing such as arithmetic processing on the pixel signals supplied from the column signal processing unit 113, while temporarily storing data in the data storage unit 119 as necessary, and outputs an image signal consisting of each pixel signal.

[0027] The data storage section 119 temporarily stores data necessary for signal processing in the signal processing section 118 .

[0028] The photodetector 1 of the present disclosure is not limited to the photodetector 1A shown in Fig. 3 and may have a configuration such as the photodetector 1B shown in Fig. 4 or the photodetector 1C shown in Fig. 5. Fig. 4 is a block diagram showing an example of the functional configuration of the photodetector 1B as a first modified example according to an embodiment of the present disclosure. Fig. 5 is a block diagram showing an example of the functional configuration of the photodetector 1C as a second modified example according to an embodiment of the present disclosure.

[0029] In the photodetector 1B of FIG. 4, a data storage unit 119 is disposed between the column signal processing unit 113 and the horizontal driving unit 114, and the pixel signals output from the column signal processing unit 113 are supplied to the signal processing unit 118 via the data storage unit 119.

[0030] 5 is configured such that a data storage unit 119 and a signal processing unit 118 are arranged in parallel between a column signal processing unit 113 and a horizontal driving unit 114. In the photodetector 1C, the column signal processing unit 113 performs A / D conversion to convert analog pixel signals into digital pixel signals for each column of the pixel array unit 111 or for each set of multiple columns of the pixel array unit 111.

[0031] [1-2. Circuit Configuration of Unit Pixel] FIG. 6 is a circuit diagram showing the circuit configuration of the unit pixel P of the photodetector 1 shown in FIG. 3 and the like.

[0032] Each unit pixel P includes a first photoelectric conversion unit 12A, a second photoelectric conversion unit 12B, a first transfer transistor TRG, a second transfer transistor FDG, a third transfer transistor FCG, a floating diffusion FD121, a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL. The unit pixel P also includes a charge storage unit FC. The charge storage unit FC is, for example, a MOS capacitor or a MIS capacitor.

[0033] The first photoelectric conversion unit 12A and the second photoelectric conversion unit 12B are so-called buried photodiodes PD1 and PD2, in which an n-type impurity region is formed inside a p-type impurity region formed in the semiconductor substrate 11. The first photoelectric conversion unit 12A and the second photoelectric conversion unit 12B each generate charges according to the amount of light received and accumulate the generated charges up to a certain amount. The first photoelectric conversion unit 12A has an anode connected to a ground voltage line and a cathode connected to the source of the first transfer transistor TRG. Like the first photoelectric conversion unit 12A, the second photoelectric conversion unit 12B has an anode connected to a ground voltage line and a cathode connected to the source of the third transfer transistor FCG.

[0034] A first transfer transistor TRG, a second transfer transistor FDG, and a third transfer transistor FCG are connected in series between the first photoelectric conversion unit 12A and the second photoelectric conversion unit 12B. A floating diffusion layer connected between the first transfer transistor TRG and the second transfer transistor FDG serves as FD121. A floating diffusion layer connected between the second transfer transistor FDG and the third transfer transistor FCG serves as a node 122. A floating diffusion layer connected between the third transfer transistor FCG and the second photoelectric conversion unit 12B serves as a node 123. A charge accumulation unit FC is connected to the node 123.

[0035] 3 and the like, a plurality of drive lines are arranged for each pixel row, for example. Various drive signals STRG, SFDG, SFCG, SRST, and SSEL are supplied to the unit pixels P from the vertical drive unit 112 via the plurality of drive lines. When each transistor of the unit pixels P is an NMOS transistor, these drive signals are pulse signals that are active when at a high level (for example, a power supply voltage VDD) and inactive when at a low level (for example, a negative potential).

[0036] The first transfer transistor TRG is connected between the first photoelectric conversion unit 12A and the FD 121. A drive signal STRG is applied to the gate electrode of the first transfer transistor TRG. When the drive signal STRG becomes active, the transfer gate of the first transfer transistor TRG becomes conductive, and the signal charge accumulated in the first photoelectric conversion unit 12A is transferred to the FD 121 via the first transfer transistor TRG.

[0037] The second transfer transistor FDG is connected between the FD121 and a node 122. A drive signal SFDG is applied to the gate electrode of the second transfer transistor FDG. When the drive signal SFDG becomes active and the second transfer transistor FDG becomes conductive, the potentials of the FD121 and the node 122 are combined to form one charge storage region.

[0038] The charges accumulated in the second photoelectric conversion unit 12B are transferred to the charge accumulation unit FC. The third transfer transistor FCG is connected between the node 122 and the node 123. A drive signal SFCG is applied to the gate electrode of the third transfer transistor FCG. When the drive signals SFDG and SFCG are activated and the second transfer transistor FDG and the third transfer transistor FCG are conductive, the potentials from the FD121 to the charge accumulation unit FC are combined to form a single charge accumulation region. When the second transfer transistor FDG and the third transfer transistor FCG are activated, the potentials from the charge accumulation unit FC to the FD121 are combined, and the charges accumulated in the second photoelectric conversion unit 12B are transferred to the combined charge accumulation region.

[0039] One of the two electrodes of the charge storage unit FC is connected to the node 123, and the other of the two electrodes of the charge storage unit FC is connected to, for example, the power supply potential FCVDD.

[0040] In addition to the second transfer transistor FDG, the reset transistor RST is connected to the node 122 .

[0041] The reset transistor RST is connected between the node 122 and the power supply VDD. A drive signal SRST is applied to the gate electrode of the reset transistor RST. When the drive signal SRST becomes active, the reset gate of the reset transistor RST becomes conductive, and the potential of the node 122 is reset to the level of the power supply VDD.

[0042] When the drive signal SRST is set to an active state, the drive signal SFDG of the second transfer transistor FDG and the drive signal SFCG of the third transfer transistor FCG are set to an active state, and the potentials of FD121, node 122, and charge storage unit FC, which are coupled to each other, are reset to the level of voltage VDD.

[0043] By individually controlling the drive signals SFDG and SFCG, the potentials of the FD 121 and the charge storage unit FC can be reset to the level of the voltage VDD independently.

[0044] The FD121 is connected between the first transfer transistor TRG, the second transfer transistor FDG, and the amplification transistor AMP. The FD121 converts the signal charges transferred by the first transfer transistor TRG and the second transfer transistor FDG into a voltage signal, and outputs the voltage signal to the amplification transistor AMP.

[0045] The amplifier transistor AMP has its gate electrode connected to the FD 121 and its drain electrode connected to the power supply VDD, and serves as the input part of a so-called source follower circuit, which is a readout circuit for a voltage signal held by the FD 121. That is, the amplifier transistor AMP has its source electrode connected to the vertical signal line 117 via the selection transistor SEL, and thereby constitutes a source follower circuit together with a constant current source connected to one end of the vertical signal line 117.

[0046] The selection transistor SEL is connected between the source electrode of the amplification transistor AMP and the vertical signal line 117. A drive signal SSEL is applied to the gate electrode of the selection transistor SEL. When this drive signal SSEL is activated, the selection transistor SEL is rendered conductive, and the unit pixel P is rendered selected. As a result, a readout signal (pixel signal) output from the amplification transistor AMP is output to the vertical signal line 117 via the selection transistor SEL.

[0047] The first photoelectric conversion unit 12A has a photodiode with a larger light receiving area than the second photoelectric conversion unit 12B. Therefore, when an object with a certain illuminance is photographed for a certain exposure time, the charge generated in the first photoelectric conversion unit 12A is greater than the charge generated in the second photoelectric conversion unit 12B.

[0048] For this reason, when the charges generated in the first photoelectric conversion unit 12A and the charges generated in the second photoelectric conversion unit 12B are transferred to the FD 121 and subjected to charge-voltage conversion, the voltage change before and after the charges generated in the first photoelectric conversion unit 12A are transferred to the FD 121 is larger than the voltage change before and after the charges generated in the second photoelectric conversion unit 12B are transferred to the FD 121. Therefore, when the first pixel unit P1 and the second pixel unit P2 are compared, the first pixel unit P1 has higher sensitivity than the second pixel unit P2.

[0049] In contrast, even if high-intensity light is incident on the second photoelectric conversion unit 12B and generates charges that exceed the saturated charge capacity of the second photoelectric conversion unit 12B, the second photoelectric conversion unit 12B can store the charges that exceed the saturated charge capacity in the charge storage unit FC.Therefore, when performing charge-to-voltage conversion on the charges generated in the second photoelectric conversion unit 12B, both the charges stored in the second photoelectric conversion unit 12B and the charges stored in the charge storage unit FC can be added together and then the charge-to-voltage conversion can be performed.

[0050] This allows the second pixel unit P2 to capture an image with greater gradation over a wider range of illumination than the first pixel unit P1, in other words, an image with a wider dynamic range.

[0051] The two images, a highly sensitive image captured using the first pixel unit P1 and a wide dynamic range image captured using the second pixel unit P2, are combined into a single image through wide dynamic range image synthesis processing, which synthesizes one image from the two images, for example, in an image signal processing circuit provided inside or outside the photodetection device 1.

[0052] 7 is a schematic diagram showing an example of a planar layout of a unit pixel P of the photodetector 1 according to this embodiment. FIG. 8 is a schematic diagram showing an example of a cross-sectional configuration of the photodetector 1 taken along line II in FIG.

[0053] The photodetector 1 has a pixel array section 111 in which a plurality of unit pixels P, each including a first pixel section P1 and a second pixel section P2, are arranged in an array. The first pixel section P1 and the second pixel section P2 each have a polygonal shape and share one side with each other. In this embodiment, for example, as shown in FIG. 1 , the first pixel section P1 has a substantially octagonal shape in plan view, and the second pixel section P2 has a substantially square shape in plan view, and they share one side with each other.

[0054] As described above, the photodetection device 1 is, for example, a back-illuminated image sensor, and each of the plurality of unit pixels P arranged two-dimensionally in a matrix in the pixel array section 111 has a configuration in which, for example, a light receiving section 10, a light collecting section 20 provided on the light incident side S1 of the light receiving section 10, and a multilayer wiring layer 30 provided on the side opposite the light incident side S1 of the light receiving section 10 are stacked.

[0055] The light receiving unit 10 includes a semiconductor substrate 11 having a first surface 11S1 and a second surface 11S2 facing each other, and a plurality of first photoelectric conversion units 12A and second photoelectric conversion units 12B having different light receiving areas that are embedded in the semiconductor substrate 11. The semiconductor substrate 11 is made of, for example, a silicon substrate. The first photoelectric conversion units 12A and second photoelectric conversion units 12B are, for example, PIN (Positive Intrinsic Negative) type photodiodes (PD), and have pn junctions in predetermined regions of the semiconductor substrate 11.

[0056] As described above, the unit pixel P has a first pixel portion P1 and a second pixel portion P2 that have different sensitivities. Specifically, the first pixel portion P1 converts a larger amount of charge per unit time than the second pixel portion P2 and has a first photoelectric conversion portion 12A that has a larger light-receiving area than the second photoelectric conversion portion 12B. The second pixel portion P2 converts a smaller amount of charge per unit time than the first pixel portion P1 and has a second photoelectric conversion portion 12B that has a smaller light-receiving area than the first photoelectric conversion portion 12A.

[0057] The light receiving section 10 further includes an element isolation section 13. The element isolation section 13 is provided between adjacent unit pixels P. Furthermore, the element isolation section 13 is also provided between the first pixel section P1 and the second pixel section P2. The element isolation section 13 corresponds to a specific example of an "isolation section" according to one aspect of the present disclosure.

[0058] The element isolation portion 13 serves to electrically isolate adjacent unit pixels P and the first pixel portion P1 and the second pixel portion P2 provided within the unit pixel P. The element isolation portion 13 has, for example, a so-called FTI (Full Trench Isolation) structure that penetrates between the first surface 11S1 and the second surface 11S2 of the semiconductor substrate 11. Alternatively, the element isolation portion 13 may have a so-called STI (Shallow Trench Isolation) structure that extends from the first surface 11S1 side of the semiconductor substrate 11 to the second surface 11S2 side or from the second surface 11S2 to the first surface 11S1 side and has a bottom surface within the semiconductor substrate 11. The element isolation portion 13 is formed, for example, by an insulating film or an impurity-implanted region.

[0059] A fixed charge layer 14 is further provided on the first surface 11S1 of the semiconductor substrate 11, and serves to prevent reflection on the first surface 11S1. The fixed charge layer 14 may be a film having a positive fixed charge or a film having a negative fixed charge. Examples of materials constituting the fixed charge layer 14 include semiconductor materials or conductive materials having a band gap wider than that of the semiconductor substrate 11. Specifically, for example, hafnium oxide (HfO ｘ ), aluminum oxide (AlO ｘ ), zirconium oxide (ZrO ｘ ), tantalum oxide (TaO ｘ ), titanium oxide (TiO ｘ ), lanthanum oxide (LaO ｘ ), praseodymium oxide (PrO ｘ ), cerium oxide (CeO ｘ ), neodymium oxide (NdO ｘ ), promethium oxide (PmO ｘ ), samarium oxide (SmO ｘ ), europium oxide (EuO ｘ ), gadolinium oxide (GdO ｘ ), terbium oxide (TbO ｘ ), dysprosium oxide (DyO ｘ ), holmium oxide (HoO ｘ ), thulium oxide (TmO ｘ ), ytterbium oxide (YbO ｘ ), lutetium oxide (LuOｘ ), yttrium oxide (YO ｘ ), hafnium nitride (HfN ｘ ), aluminum nitride (AlN ｘ ), hafnium oxynitride (HfO ｘ N ｙ ) and aluminum oxynitride (AlO ｘ N ｙ The fixed charge layer 14 may be a single layer film or a laminated film made of different materials.

[0060] The light collecting unit 20 is provided on the first surface 11S1 of the semiconductor substrate 11, which is the light incident side of the light receiving unit 10, and includes, for example, an insulating layer 21, a color filter 22 that selectively transmits, for example, red light (R), green light (G), or blue light (B) for each unit pixel P, and a light-shielding unit 23 provided between the unit pixels P of the color filter 22. The light collecting unit 20 includes a first lens 241 and a second lens 242. The first lens 241 is disposed on the color filter 22 in the first pixel unit P1. The second lens 242 is disposed on the color filter 22 in the second pixel unit P2.

[0061] The insulating layer 21 is intended to reduce deterioration of dark characteristics, and is provided, for example, on the fixed charge layer 14. Furthermore, by appropriately setting the refractive index and film thickness of the material of the insulating layer 21, it is possible to suppress the reflection of light caused by the difference in refractive index between the semiconductor substrate 11 and the color filter 22. The constituent material of the insulating layer 21 is preferably a material with a lower refractive index than the fixed charge layer 14, and for example, silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ) and silicon oxynitride (SiO ｘ N ｙ ) etc.

[0062] The color filters 22 selectively transmit light of a predetermined wavelength and are provided between the first photoelectric conversion unit 12A and the first lens 241 and between the second photoelectric conversion unit 12B and the second lens 242. The color filters 22 include, for example, a color filter 22G that selectively transmits green light (G), a color filter 22R that selectively transmits red light (R), and a color filter 22B that selectively transmits blue light (B). The color filters 22 may also include filters that selectively transmit cyan, magenta, and yellow, respectively. In the unit pixels P provided with the color filters 22R, 22G, and 22B, for example, light of a corresponding color is detected in each unit pixel P.

[0063] The color filters 22 are arranged, for example, in a 2-row x 2-column array of four unit pixels P. Two color filters 22G that selectively transmit green light (G) are arranged on a diagonal line, and color filters 22R, 22B that selectively transmit red light (R) and blue light (B) are arranged on orthogonal diagonals. In the unit pixels P provided with the color filters 22R, 22G, 22B, the corresponding color light is detected, for example, in the first photoelectric conversion unit 12A or the second photoelectric conversion unit 12B. That is, in the pixel array unit 111, unit pixels Pr, Pg, Pb that detect red light (R), green light (G), and blue light (B), respectively, are arranged in a Bayer pattern.

[0064] The color filters 22 can be formed using, for example, pigments or dyes. The thickness of the color filters 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 22. In infrared pixels, a layer made of a material that selectively transmits infrared light can be considered as the color filter 22.

[0065] The light-shielding portion 23 is intended to prevent light that is obliquely incident on the color filter 22 from leaking into adjacent unit pixels P, and is provided between adjacent unit pixels P and adjacent first pixel portions P1 and second pixel portions P2. In other words, the light-shielding portion 23 is formed in substantially the same layout as, for example, the element isolation portion 13 in plan view.

[0066] Examples of materials constituting the light-shielding portion 23 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 light-shielding portion 23 may be formed as a single-layer film or a laminated film. When the light-shielding portion 23 is formed as a laminated film, a layer made of, for example, Ti, tantalum (Ta), W, cobalt (Co), or molybdenum (Mo), or an alloy, nitride, oxide, or carbide thereof, may be provided as an underlayer to enhance adhesion with the insulating layer 21.

[0067] The light-shielding portion 23 may also serve as a light shield for the unit pixels P that determine the optical black level. The light-shielding portion 23 may also serve as a light shield for suppressing noise generation in peripheral circuits provided in the peripheral region of the pixel array portion 111. The light-shielding portion 23 is preferably grounded to prevent it from being destroyed by plasma damage caused by accumulated charges during processing.

[0068] The first lens 241 is provided for each first pixel unit P1 and is configured to focus light incident from above onto the first photoelectric conversion unit 12A. The second lens 242 is provided for each second pixel unit P2 and is configured to focus light incident from above onto the second photoelectric conversion unit 12B. The first lens 241 and the second lens 242 each have a convex shape. The first lens 241 and the second lens 242 are, for example, configured gaplessly, and, for example, in a plan view, the boundary between the element isolation unit 13 and the adjacent first lens 241 and second lens 242 approximately coincides.

[0069] In this embodiment, as described above, first lens 241 has notch 243 on the incident surface of incident light L that passes through first lens 241 and is incident in the direction of second lens 242. In other words, notch 243 is provided in the incident direction of incident light L that can pass through first lens 241 and be incident on second lens 242.

[0070] 7 , in a pixel array section 111 in which unit pixels P, each including a substantially octagonal first pixel section P1 and a substantially square second pixel section P2 sharing one side of the substantially octagon, are arranged in a two-dimensional array, four second pixel sections P2 are arranged adjacent to one first pixel section P1. Specifically, one first pixel section P1 is in contact with four second pixel sections P2 in the 45° azimuth direction and the 135° azimuth direction in the XY plane. That is, the first pixel section P1 shares a pair of sides facing each other in the 45° azimuth direction and the 135° azimuth direction, i.e., four of the eight sides constituting the octagon, with the four second pixel sections P2. In other words, the substantially square second pixel section P2 shares all four sides with the first pixel section P1 adjacent to it in the 45° azimuth direction and the 135° azimuth direction.

[0071] In the photodetector 1 having the layout described above, four cutout portions 243 are formed in the XY plane at azimuth angles of 45° and 135°, which are in contact with the second lens 242. As a result, incident light L that may pass through the first lens 241 and be incident on the second lens 242 from azimuth angles of 45° and 135°, for example, is refracted by the cutout portions 243 as shown in FIG.

[0072] The cutout portions 243, for example, cut out at right angles in the first lens 241. For example, the first lens 241 has a convex shape as described above, and has four cutout portions 243 that cut out the first lens 241 at right angles in the azimuth angle directions of 45° and 135°. As a result, the convex curved surface portion 244 of the first lens 241 where the cutout portions 243 are not formed has a substantially cross shape in a plan view.

[0073] The first lens 241 and the second lens 242 are each made of, for example, silicon oxide (SiO ｘ ) and silicon nitride (SiN ｘ Alternatively, the first lens 241 may be formed using an organic material with a high refractive index, such as an episulfide-based resin, a thietane compound, or a resin thereof.

[0074] The multilayer wiring layer 30 is provided on the side opposite to the light incident side S1 of the light receiving unit 10, specifically, on the second surface 11S2 side of the semiconductor substrate 11. The multilayer wiring layer 30 has, for example, a configuration in which a plurality of wiring layers 31, 32, and 33 are stacked with an interlayer insulating layer 34 interposed therebetween. In the multilayer wiring layer 30, for example, in addition to the circuits of the unit pixels P described above, a vertical driving unit 112, a column signal processing unit 113, a horizontal driving unit 114, a system control unit 115, a signal processing unit 118, a data storage unit 119, and the like are formed.

[0075] 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).

[0076] The interlayer insulating layer 34 is made of, for example, silicon oxide (SiO ｘ ), TEOS, silicon nitride (SiN ｘ ) and silicon oxynitride (SiO ｘ N ｙ ) or a laminated film made of two or more of these.

[0077] [1-5. Manufacturing Method of First Lens and Second Lens] The first lens 241 and the second lens 242 of this embodiment can be manufactured, for example, as follows. Figures 9A to 9F show an example of a manufacturing process for the first lens 241 and the second lens 242 of the photodetector 1.

[0078] First, as shown in FIG. 9A, a lens material 24 made of silicon nitride or the like is formed on a color filter 22 .

[0079] Next, a resist is applied to the lens material 24 at a position corresponding to the second photoelectric conversion unit 12B, and then patterned by photolithography to form a resist pattern R1 as shown in Fig. 9B. Subsequently, the resist pattern R1 is reflowed by heat treatment at, for example, 120 to 140°C, so that the corners of the resist pattern R1 are rounded as shown in Fig. 9C, and the resist pattern R1 is then cooled and hardened.

[0080] Next, a resist is applied to the lens material 24 at a position corresponding to the first photoelectric conversion portion 12A, and then patterned by photolithography to form a resist pattern R2 as shown in Fig. 9D. Subsequently, the resist pattern R2 is reflowed by heat treatment at, for example, 120 to 140°C to form the shape as shown in Fig. 9E, and then cooled and hardened.

[0081] Subsequently, the resist patterns R1 and R2 are used as masks to perform dry etching to form the first lens 241 and the second lens 242 as shown in Fig. 9F. In this way, the first lens 241 and the second lens 242 are completed.

[0082] [1-6. Actions and Effects] The photodetector 1 of this embodiment has a first photoelectric conversion unit 12A having a first lens 241 on its upper portion, and a second photoelectric conversion unit 12B that is provided adjacent to the first photoelectric conversion unit 12A and has a second lens 242 on its upper portion. The first lens 241 and the second lens 242 are in contact with each other, and the first lens 241 includes a notch 243 on its incident surface through which incident light L passes through the first lens 241 and enters the second lens 242. This prevents the first light from leaking into the second photoelectric conversion unit 12B. This is described below.

[0083] As mentioned above, imaging devices equipped with two types of photoelectric conversion units that convert different amounts of charge per unit time have problems such as deterioration of oblique incidence characteristics and colored flare. This is thought to be caused by light that is obliquely incident on a lens disposed on a photoelectric conversion unit with a large light-receiving area leaking into an adjacent photoelectric conversion unit with a smaller light-receiving area.

[0084] In particular, in an imaging device in which a photoelectric conversion unit with a small light-receiving area is arranged in the direction of azimuth angles of 45° and 135° of a photoelectric conversion unit with a large light-receiving area, light incident obliquely from the same direction is focused on the photoelectric conversion unit with the small light-receiving area, resulting in noticeable flare.

[0085] In contrast, in the photodetector 1 of this embodiment, the first lens 241 has a notch 243 provided on the incident surface through which the incident light L passes through the first lens 241 and enters the second lens 242. As a result, the incident light L that is obliquely incident on the first lens 241 is refracted at the notch 243 and travels away from the second lens 242, thereby reducing leakage into the second photoelectric conversion unit 12B. This makes it possible to expand the dynamic range and reduce flare.

[0086] 10A is a schematic diagram illustrating an example of a planar configuration of a first lens 241a and a second lens 242a of a light detection device 2 according to Modification 1 of the present disclosure. Fig. 10B is a perspective view illustrating an example of the configuration of the first lens 241a and the second lens 242a illustrated in Fig. 10A.

[0087] In the photodetector 1 according to the above embodiment, the first lens 241 and the second lens 242 have substantially the same planar shapes as the substantially octagonal first pixel portion P1 and the substantially square second pixel portion P2 that shares one side of the substantially octagon in plan view. However, the planar shapes and layouts of the first lens 241 and the second lens 242 are not limited to this.

[0088] The first lens 241a and the second lens 242a of the photodetector 2 of this modification have substantially square shapes of different sizes in a plan view, and are arranged such that the second lens 242, which is smaller than the first lens 241, partially overlaps the four corners of the first lens 241. As in the above embodiment, a notch 243a is formed at the position where the first lens 241a and the second lens 242a meet. Except for the above points, the configuration of the photodetector 2 is substantially the same as that of the photodetector 1 of the above embodiment.

[0089] Even with this configuration, the photodetector 2 can achieve the same effects as those of the above embodiment.

[0090] 11A is a schematic diagram illustrating an example of a planar configuration of a first lens 241b and a second lens 242b of a light detection device 3 according to Modification 2 of the present disclosure. Fig. 11B is a perspective view illustrating an example of the configuration of the first lens 241b and the second lens 242b illustrated in Fig. 11A.

[0091] In the photodetector 3 of this modification, the first lens 241b and the second lens 242b have a substantially square shape and a substantially circular shape, respectively, in a plan view. Specifically, the first lens 241b has a substantially square shape, as in the first modification. The second lens 242b has a substantially circular shape and is disposed so that a portion of the second lens 242b overlaps with each of the four corners of the first lens 241a. As in the above embodiment, a notch 243a is formed at the position where the first lens 241a and the second lens 242a meet. The notch 243b of this modification forms a concave curved surface in the first lens 241b. Except for the above points, the configuration of the photodetector 3 is substantially the same as that of the photodetector 1 of the above embodiment.

[0092] Even with this configuration, the photodetector 3 can obtain the same effects as those of the above embodiment.

[0093] 12A is a schematic diagram illustrating an example of a planar configuration of a first lens 241c and a second lens 242c of a light detection device 4 according to Modification 3 of the present disclosure. Fig. 12B is a perspective view illustrating an example of the configuration of the first lens 241c and the second lens 242c illustrated in Fig. 12A.

[0094] The first lens 241c and the second lens 242c of the photodetector 4 of this modification have substantially circular shapes of different sizes in a plan view, and are arranged so that a portion of the second lens 242, which is smaller than the first lens 241, overlaps with the first lens 241 in the 45° and 135° azimuth angle directions. As with the modification 2, a notch 243c that forms a concave curved surface in the first lens 241c is formed at the position where the first lens 241a and the second lens 242a meet. Except for the above points, the configuration of the photodetector 2 is substantially the same as that of the photodetector 1 of the above embodiment.

[0095] Even with this configuration, the photodetector 4 can obtain the same effects as those of the above embodiment.

[0096] [2-4. Modification 4] Fig. 13 is a schematic diagram showing an example of the planar configuration of the first lens 241d and the second lens 242d of a photodetector according to Modification 4 of the present disclosure (photodetector 5). Fig. 14 is a schematic diagram showing another example of the planar configuration of the first lens 241d and the second lens 242d of a photodetector according to Modification 4 of the present disclosure (photodetector 5A). Fig. 15 is a schematic diagram showing another example of the planar configuration of the first lens 241d and the second lens 242d of a photodetector according to Modification 4 of the present disclosure (photodetector 5B).

[0097] In the above embodiment, an example has been shown in which the cutout portion 243 cuts out the first lens 241 at a right angle, but the shape of the cutout portion 243 is not limited to this.

[0098] 13, the photodetector 5 of this modification has a cutout portion 243d formed by cutting the first lens 241d at an acute angle from the azimuth angle 45° and 135° directions where the first lens 241d contacts the second lens 242d. The cutout portion 243d may be formed by cutting deep into the vicinity of the center of the first lens 241d, as shown in FIG. 14. For example, as shown in FIG. 15, the cutout portion 243d may be formed over a narrower range so that the second lens 242d and the curved surface portion 244d of the first lens 241d contact each other partially.

[0099] Except for the above points, the configuration of the photodetector 5 is substantially the same as that of the photodetector 1 of the above embodiment. Even with this configuration, the photodetector 5 can obtain the same effects as those of the above embodiment.

[0100] 3. Application Examples (Application Example 1) The above-described light detection device 1, for example, can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, or other devices with imaging functions.

[0101] FIG. 16 is a block diagram showing an example of the configuration of electronic device 1000. As shown in FIG.

[0102] As shown in FIG. 16 , electronic device 1000 includes an optical system 1001, a photodetector 1, and a DSP (Digital Signal Processor) 1002. DSP 1002, memory 1003, a display device 1004, a recording device 1005, an operation system 1006, and a power supply system 1007 are connected via a bus 1008, and is capable of capturing still images and moving images.

[0103] The optical system 1001 is configured to have one or more lenses, and receives incident light (image light) from a subject and forms an image on the imaging surface of the photodetector 1 .

[0104] The above-described photodetection device 1 or photodetection device 1A is applied as the photodetection device 1. The photodetection device 1 converts the amount of incident light imaged on an imaging surface by an optical system 1001 into an electrical signal on a pixel-by-pixel basis and supplies the signal as a pixel signal to a DSP 1002.

[0105] The DSP 1002 performs various signal processing on the signal from the photodetector 1 to acquire an image, and temporarily stores the image data in the memory 1003. The image data stored in the memory 1003 is recorded in the recording device 1005 or supplied to the display device 1004 to display the image. In addition, the operation system 1006 accepts various operations by the user and supplies operation signals to each block of the electronic device 1000, and the power supply system 1007 supplies the power necessary to drive each block of the electronic device 1000.

[0106] 17A is a schematic diagram illustrating an example of the overall configuration of a light detection system 2000 including, for example, the light detection device 1. FIG. 17B 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. 22A ). 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 installed in, for example, an electronic device such as a smartphone or a mobile object such as a car. The light-emitting device 2001 can be configured, for example, by a semiconductor laser, a surface-emitting semiconductor laser, or a vertical-cavity surface-emitting laser (VCSEL). The method of detecting the light L2 emitted from the light-emitting device 2001 by the photodetector 2002 can be, for example, an iTOF system, but is not limited to this. In the iTOF system, the photoelectric conversion unit can measure the distance to the subject 2100, for example, by 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 system or a stereo vision system. For example, in the structured light system, 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. Furthermore, in the stereo vision system, 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] 9. Application Example 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.

[0109] FIG. 18 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.

[0110] 18 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] The light source device 11203 may also be configured to supply light in a predetermined wavelength range compatible with special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow band imaging. Alternatively, special light observation may be performed using fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light compatible with such special light observation.

[0122] FIG. 19 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0123] 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.

[0124] 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.

[0125] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as 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 configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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 .

[0132] 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.

[0133] 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.

[0134] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] The above describes an example of an endoscopic surgery system to which the technology disclosed herein can be applied. The technology disclosed herein can be applied to the imaging unit 11402 among the components described above. Applying the technology disclosed herein to the imaging unit 11402 improves detection accuracy.

[0140] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0141] (Application Example to Mobile Object) The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile object, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, construction machinery, or agricultural machinery (tractor).

[0142] FIG. 20 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.

[0143] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 20 , 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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. 20, 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.

[0153] FIG. 21 is a diagram showing an example of the installation position of the imaging unit 12031.

[0154] In FIG. 21, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0155] 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 imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0156] 21 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.

[0157] 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.

[0158] 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.

[0159] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the 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.

[0160] 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.

[0161] 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 image capture unit 12031 of the above-described configuration. Specifically, the photodetection device according to the above-described embodiment and its modified example (e.g., photodetection device 1A) can be applied to the image capture unit 12031. By applying the technology according to the present disclosure to the image capture 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.

[0162] Although the present technology has been described above with reference to the embodiment and modifications 1 to 4, the present technology is not limited to the above embodiment, etc., and various modifications are possible. For example, it is not necessary to include all of the components described in the above embodiment, etc., and conversely, other components may be included.

[0163] Furthermore, in the above embodiments, each component constituting the photodetector 1 etc. has been specifically listed and described, but it is not necessary to include all components, and other components may also be included.

[0164] Furthermore, the above modifications 1 to 5 can be combined with each other in any way.

[0165] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0166] The present disclosure may also be configured as follows. According to the present disclosure configured as follows, a notch provided on an incident surface of the first light refracts the first light and travels in a direction away from the second lens. This prevents light incident on the first lens from leaking into the second photoelectric conversion unit and causing color mixing. This makes it possible to expand the dynamic range and reduce flare. (1) A photodetector comprising: a first photoelectric conversion unit; a second photoelectric conversion unit provided adjacent to the first photoelectric conversion unit and converting a smaller amount of charge per unit time than the first photoelectric conversion unit; a first lens provided above the first photoelectric conversion unit; and a second lens provided above the second photoelectric conversion unit and in contact with the first lens, wherein the first lens has a notch on an incident surface of the first light that passes through the first lens and enters in a direction toward the second lens. (2) The photodetector according to (1), further comprising a semiconductor substrate, wherein the semiconductor substrate has a pixel array unit in which a plurality of pixels are arranged in an array. (3) The photodetector according to (2), wherein the pixel includes a first pixel portion having a first polygonal shape in a plan view and a second pixel portion having a second polygonal shape sharing one side of the first polygon. (4) The photodetector according to any one of (2) or (3), wherein the pixel includes a first pixel portion having a substantially octagonal shape in a plan view and a second pixel portion having a substantially rectangular shape sharing one side of the substantially octagon. (5) The photodetector according to (3), wherein the first photoelectric conversion portion is provided in the first pixel portion, and the second photoelectric conversion portion is provided in the second pixel portion. (6) The photodetector according to (3) or (5), wherein the first lens has four notches, and the notches are provided at positions where the first pixel portion and the second pixel portion adjacent to each other are in contact. (7) The light detecting device according to (6), wherein the four notches are provided in the azimuth angle directions of 45° and 135° of the first lens. (8) The light detecting device according to (7), wherein the entrance surface of the first lens has the four notches and a curved surface portion where no notches are formed, and the curved surface portion has a substantially cross shape in a plan view.(9) The photodetector according to (8), wherein the four cutout portions each cut out the first lens at a right angle. (10) The photodetector according to (8), wherein the four cutout portions each cut out the first lens at an acute angle. (11) The photodetector according to any one of (1) to (10), wherein the cutout portion has a concave curved surface. (12) The photodetector according to any one of (1) to (11), wherein the second lens has a smaller area than the first lens in a planar view. (13) The photodetector according to any one of (1) to (12), wherein the second lens has a substantially circular shape in a planar view. (14) The photodetector according to any one of (1) to (13), wherein the second lens has a substantially quadrangular shape in a planar view. (15) The photodetector according to any one of (1) to (14), wherein the first lens and the second lens are formed using at least one of SiO, SiN, SiON, and resin. (16) The photodetector according to any one of (1) to (15), further comprising a separator between the first photoelectric conversion unit and the second photoelectric conversion unit. (17) The photodetector according to any one of (1) to (16), further comprising color filters, each of which is provided between the first photoelectric conversion unit and the first lens and between the second photoelectric conversion unit and the second lens. (18) An electronic device comprising a photodetector, the photodetector comprising: a first photoelectric conversion unit; a second photoelectric conversion unit provided adjacent to the first photoelectric conversion unit and converting a smaller amount of charge per unit time than the first photoelectric conversion unit; a first lens provided above the first photoelectric conversion unit; and a second lens provided above the second photoelectric conversion unit and in contact with the first lens, the first lens having a notch on an incident surface for first light that passes through the first lens and is incident in the direction of the second lens.

[0167] This application claims priority based on Japanese Patent Application No. 2024-029343, filed on February 29, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0168] 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 first photoelectric conversion unit; a second photoelectric conversion unit disposed adjacent to said first photoelectric conversion unit and converting a smaller amount of electric charge per unit time than said first photoelectric conversion unit; a first lens disposed above said first photoelectric conversion unit; and a second lens disposed above said second photoelectric conversion unit and in contact with said first lens, said first lens having a notch on the incident surface for first light that passes through said first lens and is incident in the direction of said second lens.

2. The photodetector according to claim 1, further comprising a semiconductor substrate, the semiconductor substrate having a pixel array section in which a plurality of pixels are arranged in an array.

3. The photodetector device according to claim 2, wherein the pixel includes, in a plan view, a first pixel portion having a first polygonal shape and a second pixel portion having a second polygonal shape that shares one side of the first polygonal shape.

4. The photodetector according to claim 2, wherein the pixel includes a first pixel portion that is substantially octagonal in plan view, and a second pixel portion that is substantially rectangular and shares one side of the substantially octagonal shape.

5. The photodetector according to claim 3, wherein the first photoelectric conversion unit is provided in the first pixel unit, and the second photoelectric conversion unit is provided in the second pixel unit.

6. The photodetector according to claim 3, wherein the first lens has four of the notches, and the notches are provided at positions where the adjacent first pixel section and second pixel section contact each other.

7. The photodetector according to claim 6, wherein the four cutouts are provided at azimuth angles of 45° and 135° of the first lens.

8. The photodetector according to claim 7, wherein the incident surface of the first lens has four of the cutouts as well as a curved surface portion where no cutouts are formed, and the curved surface portion has a substantially cross shape in a plan view.

9. The photodetector according to claim 8, wherein each of the four cutouts cuts out the first lens at a right angle.

10. The photodetector according to claim 8, wherein each of the four cutouts cuts out the first lens at an acute angle.

11. The photodetector according to claim 1, wherein the cutout portion has a concave curved surface.

12. The photodetector according to claim 1, wherein the second lens has a smaller area than the first lens in a plan view.

13. The photodetector according to claim 1, wherein the second lens has a substantially rectangular shape in a plan view.

14. The photodetector according to claim 1, wherein the second lens has a substantially circular shape in a plan view.

15. The photodetector according to claim 1, wherein the first lens and the second lens are formed using at least one of SiO, SiN, SiON, and resin.

16. The photodetector according to claim 1, further comprising a separator between the first photoelectric conversion section and the second photoelectric conversion section.

17. The photodetector according to claim 1, further comprising color filters provided between the first photoelectric conversion unit and the first lens and between the second photoelectric conversion unit and the second lens.

18. An electronic device comprising a photodetector comprising: a first photoelectric conversion unit; a second photoelectric conversion unit disposed adjacent to the first photoelectric conversion unit and converting a smaller amount of charge per unit time than the first photoelectric conversion unit; a first lens disposed above the first photoelectric conversion unit; and a second lens disposed above the second photoelectric conversion unit and in contact with the first lens, wherein the first lens has a notch on the incident surface for first light that passes through the first lens and is incident in the direction of the second lens.

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