Light detection device and distance measuring system

Abstract

A light detection device according to an embodiment of the present disclosure includes: a first semiconductor layer having a light receiving element capable of receiving light and outputting a current; a trench provided in the first semiconductor layer to surround the light receiving element; a light shielding film provided in the trench and made of a metal material; and a first wiring provided on a first surface side of the first semiconductor layer. The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer. The first wiring is made of polycrystalline silicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film.

Description

Technical Field

[0001] The present disclosure relates to a light detection device and a distance measurement system. Background Art

[0002] There is proposed a device which includes a plurality of pixels having single photon avalanche diode (SPAD) elements and performs light detection (Patent Document 1).

[0003] Citation list

[0004] Patent Literature

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-34559 Summary of the invention

[0006] A light detection device that suppresses an increase in power consumption is required.

[0007] It is desirable to provide a light detection device capable of reducing power consumption.

[0008] A light detection device according to an embodiment of the present disclosure includes: a first semiconductor layer including a light receiving element configured to receive light and output current; a groove provided in the first semiconductor layer, the groove surrounding the light receiving element; a light shielding film provided in the groove, the light shielding film including a metal material; and a first wiring provided on the first surface side of the first semiconductor layer. The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer. The first wiring includes polycrystalline silicon or amorphous silicon and electrically connects the first semiconductor region and the light shielding film.

[0009] A distance measuring system according to an embodiment of the present disclosure includes: a light source configured to apply light to a target object and a light detecting device that receives light from the target object. The light detecting device includes: a first semiconductor layer, which includes a light receiving element configured to receive light and output current; a groove provided in the first semiconductor layer, the groove surrounding the light receiving element; a light shielding film provided in the groove, the light shielding film including a metal material; and a first wiring provided on the first surface side of the first semiconductor layer. The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer. The first wiring includes polycrystalline silicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagram showing an example of a schematic configuration of a light detecting device according to an embodiment of the present disclosure.

[0011] Figure 2 is a diagram showing a configuration example of a light detecting device according to an embodiment of the present disclosure.

[0012] Figure 3A is a diagram showing a configuration example of a pixel of a light detection device according to an embodiment of the present disclosure.

[0013] Figure 3B is a diagram showing another configuration example of a pixel of a light detection device according to an embodiment of the present disclosure.

[0014] Figure 4A : is a diagram for explaining an example of a cross-sectional configuration of a pixel of a light detection device according to an embodiment of the present disclosure.

[0015] Figure 4B is a diagram for explaining an example of a planar configuration of a pixel of a light detection device according to an embodiment of the present disclosure.

[0016] Figure 5A is a diagram showing an example of a cross-sectional configuration of a light detecting device according to an embodiment of the present disclosure.

[0017] Figure 5B is a diagram showing an example of a planar configuration of a light detecting device according to an embodiment of the present disclosure.

[0018] Figure 6 is a diagram showing another example of a cross-sectional configuration of the light detecting device according to an embodiment of the present disclosure.

[0019] Figure 7 is a diagram showing an example of a schematic configuration of a distance measuring system according to an embodiment of the present disclosure.

[0020] Figure 8 It is a diagram for explaining an example of a planar structure of a pixel of a light detection device according to Modification 1 of the present disclosure.

[0021] Fig. 9 It is a diagram for explaining an example of a cross-sectional structure of a pixel of a light detection device according to Modification 2 of the present disclosure.

[0022] Fig.10 It is a diagram for explaining an example of a cross-sectional structure of a pixel of a light detection device according to Modification 3 of the present disclosure.

[0023] Fig.11 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0024] Fig.12 It is a diagram for assisting in explaining an example of the installation positions of the vehicle exterior information detection unit and the imaging unit.

[0025] Fig.13 is a diagram showing an example of a schematic configuration of an endoscopic surgery system.

[0026] Fig.14 : is a block diagram showing an example of the functional configuration of a camera head and a camera control unit (CCU). DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the description will be given in the following order.

[0028] 1. Implementation Plan

[0029] 2. Modifications

[0030] 3. Usage Examples

[0031] 4. Application

[0032] <1. Implementation Plan>

[0033] Figure 1 1 is a diagram showing an example of a schematic configuration of a light detection device according to an embodiment of the present disclosure. The light detection device 1 is a device configured to detect incident light. The light detection device 1 includes a plurality of pixels P each including a light receiving element. The light detection device 1 is configured to perform photoelectric conversion on the incident light to generate a signal. The light detection device 1 can be used for a distance sensor, an image sensor, etc.

[0034] The light detection device 1 includes, for example, a distance measuring sensor configured to perform distance measurement of a TOF (Time of Flight) scheme. Note that the light detection device 1 can be used as a sensor configured to detect events, for example, an event-driven sensor (referred to as EVS (Event Vision Sensor), EDS (Event Driven Sensor), DVS (Dynamic Vision Sensor), etc.).

[0035] exist Figure 1 In the illustrated example, the light detection device 1 has a region including a plurality of pixels P arranged two-dimensionally as a pixel array 100. The pixel array 100 is a pixel section having pixels P arranged in a matrix. The light receiving element of each pixel P includes, for example, an avalanche photodiode (APD) element.

[0036] The pixel P includes, for example, a SPAD element as a light receiving element (light receiver). The light detection device 1 is connected to the optical system ( Figure 1 The light receiving element (not shown) captures incident light (image light) from the object to be measured. The light receiving element can receive the light and generate electric charge through photoelectric conversion, and generate photocurrent.

[0037] The light detection device 1 includes a signal processing section 110 configured to perform signal processing. The signal processing section 110 is a signal processing circuit that performs signal processing (information processing). The signal processing section 110 performs various types of signal processing on the signal of each pixel and outputs the signal of the pixel after the signal processing.

[0038] The signal processing unit 110 also serves as a control unit and is configured to control various parts of the light detection device 1. The signal processing unit 110 includes, for example, a plurality of logic circuits. As an example, the signal processing unit 110 includes a plurality of logic circuits including a timing generator, a shift register, an address decoder, and a memory that generate various types of timing signals. The signal processing unit 110 can supply a signal for the pixel P to be driven to each pixel P and control the operation of each pixel P.

[0039] Figure 2 1 is a diagram showing a configuration example of a light detecting device according to an embodiment. Figure 2 As shown, the light detection device 1 includes a first semiconductor chip (also referred to as a pixel chip 101) and a second semiconductor chip (also referred to as a circuit chip 102). The pixel chip 101 and the circuit chip 102 are stacked to overlap each other.

[0040] The light detection device 1 has a structure (stacked structure) in which the pixel chip 101 and the circuit chip 102 are stacked in the Z-axis direction. Figure 2 As shown, it is assumed that the incident direction of light from the subject to be measured is the Z-axis direction, the lateral direction of the paper plane orthogonal to the Z-axis direction is the X-axis direction, and the direction orthogonal to the Z and X axes is the Y-axis direction. Figure 2 The arrow direction in the figure is used as a reference to illustrate the direction.

[0041] The pixel chip 101 is provided with a light receiving element 10 of each pixel P of the pixel array 100. In the pixel chip 101, a plurality of light receiving elements 10 are arranged in a horizontal direction (row direction) as a first direction and in a vertical direction (column direction) as a second direction orthogonal to the first direction. The circuit chip 102 is provided with, for example, the above-mentioned signal processing section 110.

[0042] Figure 3A 1 is a diagram showing a configuration example of a pixel of a light detecting device according to an embodiment. The pixel P of the light detecting device 1 includes a light receiving element 10 and a reading circuit 15. The reading circuit 15 is configured to output a signal based on the current of the light receiving element 10. The reading circuit 15 includes a circuit for reading out a signal based on the photocurrent flowing through the light receiving element 10, for example, a generation unit 20, a supply unit 25, and a logic circuit 30.

[0043] The light receiving element 10 is configured to receive light and generate a signal. As will be described below, the light receiving element 10 as a SPAD element includes a breakdown region (breakdown portion) that causes avalanche breakdown. The light receiving element 10 can convert incoming photons into electric charges and output a signal S1, which is an electrical signal corresponding to the incoming photons. Note that the light receiving element 10 can also be referred to as a photoelectric conversion element (photoelectric converter), which is configured to perform photoelectric conversion on light.

[0044] The light receiving element 10 is electrically connected to, for example, a power supply line, an electrode, or the like configured to supply a predetermined voltage. Figure 3A In the example shown, the light receiving element 10 has a wiring ( Figure 3A For example, a power supply voltage (current) is supplied from a power source (voltage source) configured to supply voltage (current) to the anode of the light receiving element 10 via the anode wiring L1. Figure 3A The light receiving element 10 has a cathode as another electrode electrically connected to a wiring, an electrode, or the like supplied with a power supply voltage Vdd via a supply unit 25.

[0045] Between the cathode and anode of the light receiving element 10, a voltage having a potential difference greater than the breakdown voltage of the light receiving element 10 can be applied by using a voltage supplied via the supply unit 25. That is, the potential difference between the two ends of the light receiving element 10 can be set to a voltage difference greater than the breakdown voltage. When a reverse bias voltage higher than the breakdown voltage is supplied, the light receiving element 10 enters a state operable in Geiger mode. The light receiving element 10 in Geiger mode causes an avalanche breakdown phenomenon when photons are incident, and generates a current in the form of a pulse. In the pixel P, a signal S1 according to the photocurrent flowing through the light receiving element 10 caused by the incident photons is output to the generating unit 20.

[0046] The generating unit 20 is configured to generate a signal S2 based on the signal S1 generated by the light receiving element 10. Figure 3A In the example shown, the generating unit 20 comprises an inverter. The generating unit 20 comprises a transistor M1 and a transistor M2 connected in series. The transistor M1 and the transistor M2 are each a MOS transistor (MOSFET) having a gate, a source and a drain terminal. The transistor M1 is an NMOS transistor, and the transistor M2 is a PMOS transistor.

[0047] The input section of the generating unit 20 is electrically connected to the cathode of the light receiving element 10 and the supply unit 25. The output section of the generating unit 20 is electrically connected to the logic circuit 30. The input section of the generating unit 20 is electrically connected to the wiring (cathode wiring L2 in FIG. 3 ) connecting the light receiving element 10 and the supply unit 25.

[0048] The generating unit 20 receives the signal S1 from the light receiving element 10. The signal level of the signal S1, that is, the voltage (potential) of the signal S1, changes according to the current flowing through the light receiving element 10. For example, in the case where the voltage of the signal S1 is higher than the threshold value, the generating unit 20 outputs the signal S2 of the low level. In addition, in the case where the voltage of the signal S1 is lower than the threshold value, the generating unit 20 outputs the signal S2 of the high level. The generating unit 20 can output the signal S2 serving as a pulse signal based on the voltage of the signal S1 to the logic circuit 30.

[0049] exist Figure 3A In the example shown, when the voltage of signal S1 is lower than the threshold voltage of the inverter as the generating unit 20 due to the light receiving element 10 receiving photons, the inverter changes the voltage of signal S2 from low level to high level. Note that the generating unit 20 may include a buffer circuit and an AND circuit.

[0050] The supply unit 25 is configured to supply voltage and current to the light receiving element 10. The supply unit 25 is electrically connected to a power supply line supplied with a power supply voltage Vdd so that the voltage and current are supplied to the light receiving element 10. Figure 3A In the example shown, the supply unit 25 includes a transistor M3. The transistor M3 is, for example, a PMOS transistor. Note that the supply unit 25 may include a resistance element.

[0051] In the case where avalanche breakdown occurs and the potential difference between the electrodes of the light receiving element 10 is less than the breakdown voltage, the supply unit 25 can supply current to the light receiving element 10. The supply unit 25 recharges the light receiving element 10 so that the light receiving element 10 enters an operable state in the Geiger mode again. The supply unit 25 is a recharging unit, and it can also be said that it recharges the light receiving element 10 with electric charge and recharges the voltage of the light receiving unit 10. In addition, the supply unit 25 is also called a quenching unit (quenching circuit).

[0052] As described above, when photons enter the light receiving element 10 and avalanche breakdown occurs, the current flowing through the light receiving element 10 increases, causing the potential difference between the cathode and anode of the light receiving element 10 to become smaller. Figure 3A In the example shown, the cathode voltage of the light receiving element 10 decreases, and the voltage of the signal S1 to be input to the generating unit 20 decreases. Avalanche breakdown quenching is achieved by making the potential difference between the electrodes of the light receiving element 10 smaller than the breakdown voltage. As the voltage of the signal S1 decreases, the generating unit 20 changes the voltage of the signal S2 from a low level to a high level.

[0053] When the current (recharging current) from the supply unit 25 is supplied to the light receiving element 10, the potential difference between the electrodes of the light receiving element 10 is made larger. Figure 3A In the example shown, the cathode voltage of the light receiving element 10, that is, the voltage of the signal S1, rises. When the potential difference between the electrodes of the light receiving element 10 is made greater than the breakdown voltage, the light receiving element 100 enters a state operable in the Geiger mode again. As the voltage of the signal S1 rises, the generation unit 20 changes the voltage of the signal S2 from a high level to a low level. As described above, the generation unit 20 can output the signal S2 used as a pulse signal based on the voltage of the signal S1 to the logic circuit 30.

[0054] The logic circuit 30 includes a counter circuit and a TDC (time digital converter) circuit. For example, the logic circuit 30 is configured to perform counting (calculation) according to the signal input. The logic circuit 30 can count the pulses of the signal S2, generate a signal based on the number of pulses and the pulse width of the signal S2, and output the signal to the signal processing section 110. Note that the logic circuit 30 may include a circuit for controlling the supply unit 25.

[0055] Figure 3B 1 is a diagram showing another configuration example of a pixel of a light detection device according to an embodiment. The reading circuit 15 may include Figure 3B The output control unit 35 shown. The output control unit 35 includes a transistor M4. The output control unit 35 is electrically connected to a wiring (cathode wiring L2 in FIG. 3 ) connecting the light receiving element 10 and the supply unit 25. The transistor M4 is, for example, an NMOS transistor.

[0056] The output control unit 35 is configured to control the output of the signal of the light receiving element 10. The output control unit 35 can be controlled by a signal input to the gate of the output control unit 35, and can control the reading timing of the signal of the light receiving element 10. For example, in a case where the transistor M4 of the output control unit 35 is in an off state, a signal S1 corresponding to the reception of a photon can be output to the generating unit 20. Note that the output control unit 35 can also be said to be a selection unit configured to select which pixel P is to be read.

[0057] Figure 4A is a diagram for explaining an example of a cross-sectional configuration of a pixel of a light detection device according to the embodiment. Figure 4B 1 is a diagram for explaining an example of a planar configuration of a pixel of a light detecting device according to an embodiment. As described above, the light detecting device 1 includes a pixel chip 101 and a circuit chip 102. The pixel chip 101 and the circuit chip 102 each include a semiconductor substrate (e.g., a silicon substrate or an SOI (silicon on insulator) substrate).

[0058] like Figure 4AAs shown, the pixel chip 101 includes a first semiconductor layer 81, a first insulating layer 85, a second semiconductor layer 91, and a second insulating layer 95. The pixel chip 101 has a configuration in which the first semiconductor layer 81, the first insulating layer 85, the second semiconductor layer 91, and the second insulating layer 95 are stacked in the Z-axis direction. The first insulating layer 85 and the second insulating layer 95 each include a single-layer film including, for example, one of an oxide film (e.g., a silicon oxide film), a nitride film (e.g., a silicon nitride film), and an oxynitride film, or include a stacked film including two or more of them.

[0059] like Figure 4A As shown, the first semiconductor layer 81 includes a first surface 11S1 and a second surface 11S2 opposite to each other. The insulating layer 85 is provided on the first surface 11S1 side of the first semiconductor layer 81. The lens portion 16 is provided on the second surface 11S2 side of the first semiconductor layer 81. It can also be said that the lens portion 16 is provided on the side where light from the optical lens system enters, and the first insulating layer 85 is provided on the side opposite to the side where the light enters.

[0060] The pixel chip 101 is provided with a plurality of pixels P each including a light receiving element 10. On the second surface 11S2 side of the first semiconductor layer 81, for example, a lens section 16 or the like that collects light is provided for each pixel P. The lens section 16 is an optical member also called an on-chip lens.

[0061] Note that a color filter configured to selectively transmit light in a specific wavelength region of incident light may be provided on the second surface 11S2 side of the first semiconductor layer 81. Examples of the filter include RGB filters, complementary color filters, and filters for infrared light to pass through. The filter is provided between the lens portion 16 and the first semiconductor layer 81.

[0062] like Figure 4A As shown, the first semiconductor layer 81 includes semiconductor regions 40, 41 and 42 and semiconductor regions 51, 52 and 53. The semiconductor region 41 and the semiconductor region 42 are provided for each pixel P. The semiconductor region 40 is provided around the semiconductor region 41 and the semiconductor region 42. It can also be said that the semiconductor region 41 and the semiconductor region 42 are arranged to replace a part of the semiconductor region 40. The semiconductor region 41 has a different conductivity type from the semiconductor region 42, and vice versa.

[0063] For example, the semiconductor region 41 is a p-type semiconductor region and is a semiconductor layer formed using p-type impurities. The semiconductor region 41 is a p-type diffusion region and can also be said to be a p-type conductive layer. In addition, the semiconductor region 42 is an n-type semiconductor region and is a semiconductor layer formed using n-type impurities. The semiconductor region 42 is an n-type diffusion region and can also be said to be an n-type conductive layer.

[0064] exist Figure 4A and Figure 4B In the example shown, the p-type semiconductor region 41 has a higher impurity concentration than the semiconductor region 40 and thus functions as a (p+)-type semiconductor region. In addition, the n-type semiconductor region 42 has a higher impurity concentration than the semiconductor region 40 and thus functions as an (n+)-type semiconductor region.

[0065] like Figure 4A As shown schematically, the light receiving element 10 includes a p-type semiconductor region 41 and an n-type semiconductor region 42, and includes a breakdown region 45 (breakdown portion) that causes avalanche breakdown. The pixel P can also be said to be a breakdown pixel including the breakdown region 45. The breakdown region 45 includes a p-type semiconductor region 41 and an n-type semiconductor region 42. The semiconductor region 40 can perform photoelectric conversion on the incident light to generate charge, and transfer the charge to the breakdown region 45 side. The semiconductor region 40 is, for example, an n-type semiconductor region.

[0066] The semiconductor region 51 and the semiconductor region 52 in the first semiconductor layer 81 are provided for each pixel P. The semiconductor region 51 and the semiconductor region 52 are provided on the first surface 11S1 side of the first semiconductor layer 81. The semiconductor region 51 and the semiconductor region 52 are adjacent to the first surface 11S1 of the first semiconductor layer 81. The semiconductor region 51 has a conductivity type different from that of the semiconductor region 52, and vice versa.

[0067] In the first semiconductor layer 81, a semiconductor region 51 and a semiconductor region 52 are formed along the first surface 11S1 of the first semiconductor layer 81 for each pixel P. At least a portion of the semiconductor region 51 is provided to the first surface 11S1 (end surface) of the first semiconductor layer 81. In addition, at least a portion of the semiconductor region 52 is provided to the first surface 11S1 of the first semiconductor layer 81.

[0068] For example, the semiconductor region 51 is a p-type semiconductor region and is a semiconductor layer formed using p-type impurities. The semiconductor region 51 is a p-type diffusion region and can also be said to be a p-type conductive layer. In addition, the semiconductor region 52 is an n-type semiconductor region and is a semiconductor layer formed using n-type impurities. The semiconductor region 52 is an n-type diffusion region and can also be said to be an n-type conductive layer.

[0069] exist Figure 4A and Figure 4B In the example shown, the impurity concentration of the p-type semiconductor region 51 is higher than the impurity concentration of the p-type semiconductor region 41, and thus it is used as a (p++)-type semiconductor region. In addition, the impurity concentration of the n-type semiconductor region 52 is higher than the impurity concentration of the n-type semiconductor region 42, and thus it is used as a (n++)-type semiconductor region.

[0070] The p-type semiconductor region 51 is provided on the p-type semiconductor region 53 and is in contact with the p-type semiconductor region 53. The p-type semiconductor region 51 is electrically connected to the p-type semiconductor region 41 via the p-type semiconductor region 53. The p-type semiconductor region 41, the p-type semiconductor region 51, etc. are the anode region of the light receiving element. The p-type semiconductor region 51 is an anode electrode and can also be said to be a contact region.

[0071] The n-type semiconductor region 52 is disposed on the n-type semiconductor region 42 and contacts the n-type semiconductor region 42. The n-type semiconductor region 52 is electrically connected to the n-type semiconductor region 42. The n-type semiconductor region 42, the n-type semiconductor region 52, etc. are cathode regions of the light receiving element. The n-type semiconductor region 52 is a cathode electrode and can also be said to be a contact region. The p-type semiconductor region 51 and the n-type semiconductor region 52 as contact regions include a (p++)-type semiconductor region and a (n++)-type semiconductor region, respectively, thereby reducing contact resistance.

[0072] Figure 4A The separator 60 shown is provided between adjacent light receiving elements 10 to separate the light receiving elements 10. The separator 60 has a groove structure provided at the boundary between adjacent pixels P (or light receiving elements 10), and can also be said to be an inter-pixel separator or an inter-pixel separator wall. Figure 4A In the example shown, the separation portion 60 is provided to penetrate the first semiconductor layer 81 .

[0073] The separation portion 60 includes a groove 61 (groove) and a light shielding film 65. In the first semiconductor layer 81, the groove 61 is provided to surround the light receiving element 10. In the groove 61, a light shielding film 65 including a metal material is provided. The groove 61 (groove) is formed between adjacent light receiving elements 10, and the light shielding film 65 which is a metal film is embedded in the groove 61. Note that in the separation portion 60, an insulating film covering the inner surface of the groove 61 may be formed.

[0074] like Figure 4A and Figure 4B In the example shown, the separator 60 is arranged to surround the light receiving element 10. The separator 60 is formed in a grid shape and is therefore arranged at the boundary between two adjacent pixels P (or light receiving elements 10). The plurality of light receiving elements 10 of the light detection device 1 are electrically insulated from each other by the separator 60. It can also be said that the light receiving element 10 is arranged in sections by the separator 60.

[0075] The light shielding film 65 (light shielding portion) includes a member that blocks light. For example, the light shielding film 65 includes a metal material that blocks light, such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf), or tantalum (Ta).

[0076] The light shielding film 65 is located between adjacent light receiving elements 10 to suppress light leakage into surrounding pixels P. In the light detection device 1, by providing the light shielding film 65, light leakage into surrounding pixels P is suppressed, thereby suppressing color mixing. Note that the light shielding film 65 may include a material that absorbs light.

[0077] The semiconductor region 53 is a p-type semiconductor region and is a semiconductor layer formed using p-type impurities. The semiconductor region 53 is provided between the semiconductor region 40 and the separation portion 60 to suppress the occurrence of dark current. Figure 4A and Figure 4B In the example shown, the p-type semiconductor region 53 has a higher impurity concentration than the semiconductor region 40 and thus functions as a (p+)-type semiconductor region. The p-type semiconductor region 53 is arranged along the periphery of the separation portion 60 and is electrically connected to the p-type semiconductor region 51 .

[0078] like Figure 4A As shown, the pixel P of the light receiving element 1 includes a first wiring 71 and a second wiring 72. The first wiring 71 is a wiring including polysilicon, and is provided on the first surface 11S1 side of the first semiconductor layer 81. Note that the first wiring 71 may include amorphous silicon.

[0079] exist Figure 4A In the example shown, the first wiring 71 is arranged on the first surface 11S1 of the first semiconductor layer 81 and is located on the semiconductor region 51 and the separation portion 60. On the first surface 11S1 side of the first semiconductor layer 81, the first wiring 71 is provided to cover the semiconductor region 51 and the separation portion 60 including the light shielding film 65. Figure 4A and Figure 4B As shown, the first wiring 71 is formed to surround the light receiving element 10 .

[0080] The first wiring 71 is configured to electrically connect the p-type semiconductor region 51 serving as the anode and the light shielding film 65. Figure 4A In the example shown, the first wiring 71 is directly connected to the p-type semiconductor region 51 and the light shielding film 65. The first wiring 71 can also be said to be a part of the anode wiring L1. Figure 4A In the illustrated example, no wiring is provided between the first wiring 71 and the second semiconductor layer 91. The upper portion of the first wiring 71 is covered with an insulating film.

[0081] The first wiring 71 is formed as follows Figure 4A and Figure 4B The first wiring 71 is a grid-like shape as shown, and is commonly connected to the p-type semiconductor region 51 and the light shielding film 65 of each of the plurality of pixels p. The first wiring 71 serves as a wiring commonly used by the plurality of pixels P.

[0082] Figure 4AThe first semiconductor layer 81 and the second semiconductor layer 91 shown are arranged to sandwich the first insulating layer 85. The second semiconductor layer 91 is provided with at least a portion of the above-mentioned reading circuit 15. For example, Figure 4A In the example shown, the second semiconductor layer 91 includes an island-shaped element formation region. For example, in the second semiconductor layer 91, transistors of the generation unit 20, transistors of the supply unit 25, transistors of the output control unit 35, etc. can be arranged. A portion of the reading circuit 15 is provided above the light receiving element 10.

[0083] The second wiring 72 is a wiring formed using aluminum (Al), copper (Cu), etc. The second wiring 72 electrically connects the n-type semiconductor region 52 and the reading circuit 15. The second wiring 72 can also be said to be a part of the cathode wiring L2 described above. In the first insulating layer 85, the second wiring 72 extends in the stacking direction of the first semiconductor layer 81 and the second semiconductor layer 91 (i.e., in the Z-axis direction). The n-type semiconductor region 52 as a cathode electrode is electrically connected to the reading circuit 15 via the second wiring 72.

[0084] The second insulating layer 95 includes, for example, a conductor film and an insulating film, and includes a plurality of wirings and through holes. The second insulating layer 95 includes, for example, more than two layers of wiring. For example, the second insulating layer 95 has a structure in which a plurality of wirings are stacked and an interlayer insulating layer (interlayer insulating film) is inserted therebetween. Such wiring layers are formed using aluminum (Al), copper (Cu), tungsten (W), polysilicon (Poly-Si), etc. As an example, the interlayer insulating layer includes a single-layer film formed by one of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), etc., or a laminated film formed by two or more of them.

[0085] The second insulating layer 95 in the pixel chip 101 is provided with an electrode 75a. In addition, the insulating layer 96 in the circuit chip 102 is provided with an electrode 75b. For example, the electrodes 75a and 75b are each formed using copper (Cu). For example, the electrodes 75a and 75b are provided for each pixel P. For example, a plurality of electrodes 75a and 75b are arranged side by side at an interval substantially equal to the pitch of the pixels P (interval of the pixels P) (refer to the following description). Figure 5A , Figure 6 The electrodes 75a and 75b are each an electrode for bonding between metal electrodes and thus serve as bonding electrodes.

[0086] As an example, the pixel chip 101 and the circuit chip 102 are bonded by bonding between metal electrodes containing copper (Cu) (i.e., Cu-Cu bonding). The circuit of the pixel chip 101 and the circuit of the circuit chip 102 are electrically connected to each other through the electrodes 75a and 75b. Note that the electrodes 75a and 75b may each contain, for example, a metal material other than copper, such as nickel (Ni), cobalt (Co), tin (Sn), or gold (Au). In addition, the pixel chip 101 and the circuit chip 102 may be stacked using bumps.

[0087] Figure 5A is a diagram showing an example of a cross-sectional configuration of a light detecting device according to the embodiment. Figure 5B is a diagram showing an example of a planar configuration of a light detecting device according to the embodiment. Figure 5B FIG. 8 shows an example of arrangement of the light shielding film 65 on the second surface 11S2 side of the first semiconductor layer 81. The electrodes 75a and 75b have a pitch (arrangement interval of the electrodes 75a and 75b) substantially equal to the pixel pitch. Figure 5A and Figure 5B In the illustrated example, the light shielding film 65 is arranged in a grid-like shape on the second surface 11S2 side of the first semiconductor layer 81 .

[0088] The light shielding film 65 extends to a region outside the pixel array 100, and is electrically connected to a power supply line, a voltage source, or the like configured to supply a voltage (current). Figure 5A and Figure 5B In the example shown, the light shielding film 65 is wired to the outside of the pixel array 100 on the second surface 11S2 side of the first semiconductor layer 81, and is electrically connected to the power supply (voltage source) on the circuit chip 102 side via the wiring 77. The wiring 77 includes a through hole. Figure 6 In the illustrated example, the first wiring 71 may be wired to the outside of the pixel array 100 on the first surface 11S1 side of the first semiconductor layer 81 , and may be electrically connected to a power source on the circuit chip 102 side via the wiring 77 .

[0089] In the light detecting device 1 according to the present embodiment, as described above, the first wiring 71 is provided on the first surface 11S1 side of the first semiconductor layer 81. The first wiring 71 is connected to the p-type semiconductor region 51 as the anode electrode of the light receiving element 10, and is connected to the light shielding film 65 in the groove 61. This allows the light shielding film 65 to function as the anode wiring L1. Therefore, many wirings and contacts for the anode can be provided next to the cathode wiring L2, so that the capacitance added to the cathode wiring L2 can be prevented from increasing. The capacitance added to the cathode wiring L2 can be reduced, so that power consumption is reduced.

[0090] In the case where the pixel size is small, the increase in capacitance added to the cathode is also suppressed, so that the power consumption can be prevented from increasing. In addition, in the area stacked on the first surface 11S1 side of the first semiconductor layer 81, the area of ​​the area for wiring, transistors, etc. to be arranged can be widened, so that, for example, a wider area and multifunctional reading circuit can be arranged. This makes it possible to realize a high-performance light detection device 1 while preventing an increase in pixel size.

[0091] In addition, in the present embodiment, the light shielding film 65 which is a low resistance metal film is used, so that the anode voltage Va can be supplied to the light receiving element 10. This enables stable voltage supply. In addition, the first wiring 71 contains polysilicon or amorphous silicon. Thus, it is possible to stack and form elements such as transistors by a high temperature heat treatment process to manufacture Figure 4A The light detection device 1 shown in the figure.

[0092] Figure 7 1000 (light detection system) includes the above-described light detection device 1 , a light source 1100 , an optical system 1200 , an image processing unit 1300 , a monitor 1400 , and a memory 1500 .

[0093] The light source 1100 is configured to apply light to a target object. The light source 1100 includes a plurality of light emitting elements. Examples of light emitting elements include LEDs (light emitting diodes) and LDs (laser diodes). In the light source 1100, a plurality of light emitting elements are arranged two-dimensionally in a matrix form. The light source 1100 can generate, for example, laser light and output the laser light to the outside.

[0094] The optical system 1200 includes one or more lenses. Image light (incident light) from the target object 2000 is guided to the light detection device 1 by the optical system 1200 and is formed as an image on the light receiving surface of the light detection device 1 .

[0095] The image processing unit 1300, as an image processing circuit, can perform image processing for constructing a distance image based on the signal supplied from the light detection device 1. The distance image (image data) obtained by the image processing of the image processing unit 1300 can be supplied to the monitor 1400 and displayed thereon, and can be supplied to the memory 1500 and stored (recorded) therein.

[0096] The distance measuring system 1000 receives light (modulated light or pulse light) applied from the light source 1100 to the target object 2000 and reflected on the surface of the target object 2000 , and thus can obtain a distance image according to the distance to the target object 2000 .

[0097] [Function and Effect]

[0098] The light detecting device (light detecting device 1) according to the present embodiment includes: a first semiconductor layer (first semiconductor layer 81) including a light receiving element (light receiving element 10) configured to receive light and output current; a groove (groove 61) provided in the first semiconductor layer, the groove surrounding the light receiving element; a light shielding film (light shielding film 65) provided in the groove, the light shielding film containing a metal material; and a first wiring (first wiring 71) provided on the first surface side of the first semiconductor layer. The light receiving element includes a first semiconductor region of a first conductivity type (e.g., a p-type semiconductor region 51) and a second semiconductor region of a second conductivity type (e.g., an n-type semiconductor region 52) provided on the first surface side of the first semiconductor layer. The first wiring includes polycrystalline silicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film.

[0099] In the light detecting device 1 according to the present embodiment, on the first surface 11S1 side of the first semiconductor layer 81, a first wiring 71 is provided which electrically connects the p-type semiconductor region 51 as the anode electrode and the light shielding film 65 in the groove 61. The light shielding film 65 can be used as an anode wiring, so that the capacitance added to the cathode wiring can be reduced. This makes it possible to reduce power consumption.

[0100] Next, a modification of the present disclosure will be described. Hereinafter, components similar to those in the above-described embodiment are denoted by the same reference numerals, and description of the components is appropriately omitted.

[0101] <2. Modifications>

[0102] (2-1. Modification 1)

[0103] Although the configuration example of the pixel P is described in the above embodiment, the configuration of the pixel P is not limited thereto. For example, the above-mentioned p-type semiconductor region 51 and the first wiring 71 may be provided at the corner (corner portion) of the pixel p.

[0104] Figure 8 1 is a diagram for explaining an example of a planar structure of a pixel of a light detection device according to a modification example 1 of the present disclosure. Figure 8 In the example shown, the p-type semiconductor regions 51 and the first wiring 71 may be arranged at the four corners of the pixel p. Compared with the case where the p-type semiconductor regions 51 are arranged on the four sides, dark current due to the strong electric field generated between the anode and the cathode can be suppressed.

[0105] Note that the p-type semiconductor region 51 and the first wiring 71 may be arranged only at some of the four corners of the pixel p. In addition, the shape of each of the p-type semiconductor region 51 and the first wiring 71 is not particularly limited. The shape of each of the p-type semiconductor region 51 and the first wiring 71 may be as follows: Figure 8Rectangular shape, polygonal shape, elliptical shape or other shapes as shown.

[0106] (2-2. Modification 2)

[0107] Fig. 9 1 is a diagram for explaining an example of a cross-sectional structure of a pixel of a light detection device according to Modification Example 2. Fig. 9 As shown, a portion of the first wiring 71 is formed to be embedded in the first semiconductor layer 81, and connects the side surface of the p-type semiconductor region 51 and the light shielding film 65. In addition, the upper surface of the p-type semiconductor region 51 and the light shielding film 65 are also connected to each other through the first wiring 71. In this modification, the contact area between the first wiring 71 and the p-type semiconductor region 51 can be widened, so that the contact resistance of the anode can be reduced.

[0108] (2-3. Modification 3)

[0109] Fig.10 FIG. 1 is a diagram for explaining an example of a cross-sectional structure of a pixel of a light detection device according to Modification 3. Fig.10 In the example shown, the light detecting device 1 includes a plurality of through holes 76. Each through hole 76 is provided in the first insulating layer 85 and connects the first wiring 71 and the p-type semiconductor region 51. The through hole 76 contains polysilicon or amorphous silicon. The p-type semiconductor region 51 is electrically connected to the first wiring 71 via the through hole 76.

[0110] In addition, if Fig.10 As shown, the light shielding film 65 reaches the first wiring 71 in the first insulating layer 85. The light shielding film 65 is connected to the first wiring 71 in the first insulating layer 85. By providing the light shielding film 65 to the first insulating layer 85, crosstalk between pixels (for example, crosstalk caused by light emission of the breakdown region 45) can be suppressed. Note that the number and arrangement of the through holes 76 are not limited to the example shown, and any deformation can be appropriately performed.

[0111] (2-4. Modification 4)

[0112] In the above-mentioned embodiments and modified examples, although the configuration examples of the light receiving element 10 are described, this is only an example, and the configuration of the light receiving element 10 is not limited to the above-mentioned example. For the configuration of each of the light receiving element 10 and the breakdown region, any modification can be made as appropriate. As in the example shown, the breakdown region can be formed by a fringe electric field, or the breakdown region can be formed by arranging a p-type semiconductor region 41 and an n-type semiconductor region 42 opposite to each other in the vertical direction. For example, in Figure 4A In the embodiment, the p-type semiconductor region 41 may be provided on the entire bottom surface of the n-type semiconductor region 42 .

[0113] <3. Usage examples>

[0114] For example, the above-mentioned light detection device 1 can be used in various situations of sensing light such as visible light, infrared light, ultraviolet light or X-ray.

[0115] - A device for taking images for viewing, such as a digital camera or a mobile device with a camera function.

[0116] - Devices used for traffic safety driving such as automatic parking and driver status recognition, such as vehicle-mounted sensors that capture images of the environment in front of, behind, and around the vehicle, the interior of the vehicle, etc., surveillance cameras that monitor moving vehicles or roads, or ranging sensors that measure the distance between vehicles.

[0117] - Devices for home appliances, such as a TV, refrigerator, or air conditioner, to capture images of user gestures and perform operations according to the gestures.

[0118] - Devices used in medicine and health care, such as endoscopes or devices that perform angiography by receiving infrared light, etc.

[0119] -Devices for security, such as surveillance cameras for crime prevention or cameras for personal authentication, etc.

[0120] - Devices used for beauty care, such as a skin measurement device that takes images of the skin or a microscope that takes images of the scalp.

[0121] -Devices for sports, such as sports cameras or wearable cameras for sports.

[0122] -Devices for use in agriculture, such as cameras for monitoring the condition of fields and crops.

[0123] <4. Application>

[0124] (Application to mobile objects)

[0125] 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 can be implemented as a device installed on any type of mobile body such as a car, an electric car, a hybrid car, a motorcycle, a bicycle, a personal mobile device, an airplane, a drone, a ship, or a robot.

[0126] Fig.11 : is a block diagram showing an example of a schematic configuration of a vehicle control system as an example of a moving body control system to which the technology according to the embodiment of the present invention can be applied.

[0127] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Fig.11In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. In addition, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0128] The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various types of programs. For example, the drive system control unit 12010 serves as a control device for the following devices: a drive force generating device such as an internal combustion engine or a drive motor for generating a vehicle drive force, a drive force transmitting 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 vehicle braking force.

[0129] The body system control unit 12020 controls the operation of various types of devices provided on the vehicle body according to various types of programs. For example, the body system control unit 12020 is used as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as a headlight, a reverse light, a brake light, a turn signal light, or a fog light. In this case, a radio wave transmitted from a mobile device that replaces the key or a signal of various types of switches may be input to the body system control unit 12020. The body system control unit 12020 receives input of these radio waves or signals, and controls a door lock device, a power window device, or a light, etc. of the vehicle.

[0130] The vehicle exterior information detection unit 12030 detects information outside the vehicle including the vehicle control system 12000. For example, the vehicle exterior information detection unit 12030 is connected to the camera unit 12031. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture an image of the vehicle exterior and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform detection processing of objects such as people, vehicles, obstacles, signs, or characters on the road surface, or can perform detection processing of the distance to the above-mentioned objects.

[0131] 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 can output the electrical signal as distance measurement information. In addition, the light received by the imaging unit 12031 can be visible light, or can be invisible light such as infrared rays.

[0132] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver state detection unit 12041 that detects the driver's state. The driver state detection unit 12041 includes, for example, a camera that takes a picture of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or the driver's concentration level, or can determine whether the driver is dozing off.

[0133] The microcomputer 12051 can calculate the control target value of the driving force generating device, the steering mechanism or the braking device based on the information outside or inside the vehicle obtained by the vehicle outside information detection unit 12030 or the vehicle inside information detection unit 12040, and output the control command to the driving system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of the advanced driver assistance system (ADAS), including collision avoidance or impact mitigation of the vehicle, following driving based on the vehicle-to-vehicle distance, speed maintenance driving, vehicle collision warning or vehicle lane departure warning, etc.

[0134] In addition, by controlling the driving force generating device, steering mechanism or braking device, etc. based on the information outside or inside the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 can perform collaborative control aimed at achieving automatic driving, etc., wherein the automatic driving enables the vehicle to drive autonomously without relying on the driver's operation.

[0135] In addition, based on the information outside the vehicle obtained by the vehicle exterior information detection unit 12030, the microcomputer 12051 can output a control command to the body system control unit 12020. For example, the microcomputer 12051 can perform cooperative control aimed at preventing glare by controlling the headlights to change from high beam to low beam, for example, according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detection unit 12030.

[0136] The sound / image output unit 12052 sends an output signal of at least one of sound and image to an output device capable of visually or auditorily notifying the vehicle's passengers or the outside of the vehicle of information. Fig.11 In the example of , as the output device, an audio speaker 12061, a display portion 12062, and an instrument panel 12063 are shown. For example, the display portion 12062 may include at least one of an in-vehicle display and a head-up display.

[0137] Fig.12 12031 is a diagram showing an example of the installation position of the imaging unit 12031.

[0138] exist Fig.12 In the figure, the camera unit 12031 includes camera units 12101, 12102, 12103, 12104 and 12105.

[0139] The camera units 12101, 12102, 12103, 12104 and 12105 are, for example, arranged at the front nose, rearview mirror, rear bumper and rear door of the vehicle 12100 and at the upper part of the windshield in the vehicle compartment. The camera unit 12101 arranged at the front nose and the camera unit 12105 arranged at the upper part of the windshield in the vehicle compartment mainly obtain images in front of the vehicle 12100. The camera units 12102 and 12103 arranged at the rearview mirror mainly obtain images on both sides of the vehicle 12100. The camera unit 12104 arranged at the rear bumper or rear door mainly obtains images behind the vehicle 12100. The camera unit 12105 arranged at the upper part of the windshield in the vehicle compartment is mainly used to detect the vehicle in front, pedestrians, obstacles, traffic lights, traffic signs or lanes, etc.

[0140] By the way, Fig.12 An example of the imaging range of the imaging units 12101 to 12104 is shown. The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided at the front nose. The imaging ranges 12112 and 12113 respectively indicate the imaging ranges of the imaging units 12102 and 12103 provided at the rearview mirror. The imaging range 12114 indicates the imaging range of the imaging unit 12104 provided at the rear bumper or the rear door. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 observed from above is obtained.

[0141] At least one of the imaging units 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0142] For example, based on the distance information obtained from the camera units 12101 to 12104, the microcomputer 12051 can determine the distance to each three-dimensional object within the camera ranges 12111 to 12114 and the time change of the distance (relative speed with respect to the vehicle 12100), thereby extracting the nearest three-dimensional object as the front vehicle, in particular, the nearest three-dimensional object exists on the driving path of the vehicle 12100 and travels in the same direction as the vehicle 12100 at a predetermined speed (e.g., equal to or greater than 0 km / h). In addition, the microcomputer 12051 can pre-set the inter-vehicle distance to be maintained in front of the front vehicle, and perform automatic braking control (including follow-up stop control) or automatic acceleration control (including follow-up start control), etc. Therefore, cooperative control such as automatic driving, which aims to make the vehicle travel autonomously without relying on the driver's operation, can be performed.

[0143] For example, based on the distance information obtained from the camera units 12101 to 12104, the microcomputer 12501 can classify the three-dimensional object data of the three-dimensional object into three-dimensional object data of two-wheeled vehicles, standard vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, extract the classified three-dimensional object data, and use the extracted three-dimensional object data to automatically avoid obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that the driver of the vehicle 12100 can visually identify and obstacles that the driver of the vehicle 12100 is difficult to visually identify. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle. In the case where the collision risk is equal to or higher than the set value and therefore there is a possibility of collision, the microcomputer 12051 outputs a warning to the driver via the audio speaker 12061 or the display unit 12062, and performs forced deceleration or evasive steering via the drive system control unit 12010. Therefore, the microcomputer 12051 can assist driving to avoid collisions.

[0144] At least one of the camera units 12101 to 12104 may be an infrared camera that detects infrared rays. The microcomputer 12051 may identify a pedestrian, for example, by determining whether a pedestrian exists in the camera images of the camera units 12101 to 12104. For example, such identification of pedestrians is performed by the following steps: a step of extracting feature points in the camera images of the camera units 12101 to 12104 as infrared cameras; and a step of performing pattern matching processing on a series of feature points representing the contour of an object to determine whether it is a pedestrian. If the microcomputer 12051 determines that a pedestrian exists in the camera images of the camera units 12101 to 12104 and thus identifies the pedestrian, the sound / image output unit 12052 controls the display unit 12062 so that a square contour line for emphasis is displayed in a manner superimposed on the identified pedestrian. The sound / image output unit 12052 may also control the display unit 12062 so that an icon representing a pedestrian or the like is displayed at a desired position.

[0145] An example of a mobile body control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the camera section 12031 in the above-mentioned configuration. Specifically, for example, the camera device 1 can be applied to the camera section 12031. Applying the technology according to the present disclosure to the camera section 12031 enables obtaining a high-definition captured image, and using the captured image in the mobile body control system for high-precision control.

[0146] (Application of Endoscopic Surgery System)

[0147] 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 can be applied to an endoscopic surgery system.

[0148] Fig.13 : is a diagram showing a schematic configuration example of an endoscopic surgery system to which the technology according to the embodiment of the present invention (the present technology) can be applied.

[0149] exist Fig.13 , a state is shown in which a surgeon (doctor) 11131 is using an endoscopic surgery system 11000 to perform surgery on a patient 11132 on a bed 11133. As shown in the figure, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 (e.g., a pneumoperitoneum tube 11111 and an energy device 11112), a support arm device 11120 (supporting the endoscope 11100 thereon), and a cart 11200, on which various devices used for endoscopic surgery are loaded.

[0150] The endoscope 11100 includes a lens barrel 11101 and a camera 11102 connected to the proximal end of the lens barrel 11101, and the lens barrel 11101 has a region of a predetermined length from its distal end for insertion into a body cavity of a patient 11132. In the illustrated example, the endoscope 11100 is illustrated as a rigid endoscope including the lens barrel 11101 as having a hard type. However, the endoscope 11100 may also be a flexible endoscope including the lens barrel 11101 as having flexibility.

[0151] The lens barrel 11101 has an opening at its distal end for mounting an objective lens. The light source device 11203 is connected to the endoscope 11100 so that the light generated by the light source device 11203 is guided to the distal end of the lens barrel 11101 through a light guide extending inside the lens barrel 11101 and irradiated toward an observation target in the body cavity of the patient 11132 through the objective lens. It should be noted that the endoscope 11100 may be a forward-looking endoscope, or may be an oblique-looking endoscope or a side-looking endoscope.

[0152] An optical system and an imaging element are provided inside the camera head 11102, so that the reflected light (observation light) from the observation target is gathered on the imaging element by the optical system. The imaging element performs photoelectric conversion on the observation light to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is transmitted to the camera control unit (CCU) 11201 as raw data.

[0153] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), etc., and centrally controls the operations of the endoscope 11100 and the display device 11202. In addition, the CCU 11201 receives an image signal from the camera 11102, and performs various image processing for displaying an image based on the image signal, such as development processing (demosaic processing), on the image signal.

[0154] The display device 11202 displays an image based on an image signal that has been image-processed by the CCU 11201 under the control of the CCU 11201 .

[0155] The light source device 11203 includes a light source such as, for example, a light emitting diode (LED), and provides illumination light to the endoscope 11100 when imaging a surgical area or the like.

[0156] The input device 11204 is an input interface for the endoscopic surgery system 11000. The user can input various types of information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user will input instructions through the endoscope 11100 to change image capturing conditions (type of irradiation light, magnification or focal length, etc.).

[0157] The treatment tool control device 11205 controls the driving of the energy device 11112 for cauterizing or cutting tissue, sealing blood vessels, etc. The pneumoperitoneum device 11206 delivers gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to inflate the body cavity to ensure the field of view of the endoscope 11100 and to ensure the working space of the surgeon. The recorder 11207 is a device capable of recording various types of information related to the operation. The printer 11208 is a device capable of printing various types of information related to the operation in various forms (such as text, images, or graphics).

[0158] It should be noted that the light source device 11203 that provides irradiation light for the surgical area to be imaged to the endoscope 11100 may include a white light source such as an LED, a laser light source, or a combination thereof. In the case where the white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the white balance adjustment of the captured image can be performed by the light source device 11203. In addition, in this case, if the laser beams from each RGB laser light source are irradiated onto the observation target in a time-division manner, and the drive of the imaging element of the camera 11102 is controlled synchronously with the irradiation timing, it is also possible to capture images corresponding to each of the R, G, and B colors in a time-division manner. According to this method, a color image can be obtained even if a color filter is not provided for the imaging element.

[0159] In addition, the light source device 11203 can be controlled so that the intensity of the light to be output changes at predetermined intervals. By controlling the driving of the imaging element of the camera 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and synthesize the images, it is possible to create an image with a high dynamic range without underexposed shadows and overexposed highlights.

[0160] In addition, the light source device 11203 can be configured to provide light of a predetermined wavelength band that can be used for special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in human tissue to irradiate light of a narrower wavelength band than the irradiation light (i.e., white light) for ordinary observation, narrow-band light observation (narrow-band photography) for imaging predetermined tissues (e.g., blood vessels of the mucosal surface layer, etc.) with high contrast is performed. Alternatively, in special light observation, fluorescence observation for obtaining images by fluorescence generated by irradiation with excitation light can be performed. In fluorescence observation, fluorescence from human tissue can be observed by irradiating excitation light onto human tissue (autofluorescence observation) or a fluorescent image can be obtained by locally injecting a reagent (such as indocyanine green (ICG)) into human tissue and irradiating excitation light corresponding to the fluorescence wavelength of the reagent onto human tissue. The light source device 11203 can be configured to provide narrow-band light and / or excitation light suitable for the above-mentioned special light observation.

[0161] Fig.14 It shows Fig.13 A block diagram of an example of the functional configuration of the camera 11102 and the CCU 11201 shown.

[0162] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are connected to each other through a transmission cable 11400 for communication.

[0163] The lens unit 11401 is an optical system provided at a connection position with the lens barrel 11101. Observation light taken from the distal end of the lens barrel 11101 is guided to the camera head 11102 and introduced into the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focus lens.

[0164] The number of imaging elements included in the imaging unit 11402 can be one (single-board type) or multiple (multi-board type). For example, in the case where the imaging unit 11402 is configured as a multi-board type imaging unit, image signals corresponding to each of R, G and B are generated by the imaging element, and the image signals can be synthesized to obtain a color image. The imaging unit 11402 can also be constructed to have a pair of imaging elements for respectively acquiring image signals for the right eye and for the left eye, thereby being used for three-dimensional (3D) display. If 3D display is performed, the surgeon 11131 can more accurately understand the depth of living tissue in the surgical area. It should be noted that in the case where the imaging unit 11402 is configured as a stereoscopic type imaging unit, multiple systems of lens units 11401 are provided corresponding to the respective imaging elements.

[0165] In addition, the imaging unit 11402 does not have to be provided on the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101 just behind the objective lens.

[0166] The driving unit 11403 includes an actuator, and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera control unit 11405. Therefore, the magnification and focus of the image captured by the camera unit 11402 can be appropriately adjusted.

[0167] The communication unit 11404 includes a communication device for sending and receiving various types of information to and from the CCU 11201. The communication unit 11404 sends an image signal acquired from the imaging unit 11402 to the CCU 11201 through the transmission cable 11400 as RAW data.

[0168] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and provides the control signal to the camera control unit 11405. The control information includes information related to imaging conditions, such as, for example, information specifying a frame rate for capturing an image, information specifying an exposure value when capturing an image, and / or information specifying a magnification and a focus for capturing an image.

[0169] It should be noted that image capturing conditions such as frame rate, exposure value, magnification, or focus may be specified by a user or may be automatically set based on an acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, an automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are incorporated into the endoscope 11100.

[0170] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal received from the CCU 11201 through the communication unit 11404 .

[0171] The communication unit 11411 includes a communication device for sending various types of information to the camera 11102 and receiving various types of information from the camera 11102. Through the transmission cable 11400, the communication unit 11411 receives an image signal sent thereto from the camera 11102.

[0172] In addition, the communication unit 11411 sends a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted through electrical communication, optical communication, etc.

[0173] The image processing unit 11412 performs various image processing on the image signal in the form of RAW data sent thereto from the camera 11102 .

[0174] The control unit 11413 performs various types of control related to imaging of the operation area, etc. by the endoscope 11100 and display of a captured image obtained by imaging the operation area, etc. For example, the control unit 11413 creates a control signal for controlling the driving of the camera head 11102 .

[0175] In addition, the control unit 11413 controls the display device 11202 to display a captured image of the surgical area, etc., based on the image signal that has been image-processed by the image processing unit 11412. Therefore, the control unit 11413 can use various image recognition technologies to recognize various objects in the captured image. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living areas, bleeding, fog when the energy device 11112 is used, etc. by detecting the shape, color, etc. of the edge of the object contained in the captured image. When the control unit 11413 controls the display device 11202 to display the captured image, the control unit 11413 can use the recognition result to display various types of surgical support information in a manner overlapping with the image of the surgical area. When the surgical support information is displayed in an overlapping manner and presented to the surgeon 11131, the burden of the surgeon 11131 can be reduced, and the surgeon 11131 can perform the operation with confidence.

[0176] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 to each other is an electric signal cable capable of being used for electric signal communication, an optical fiber capable of being used for optical communication, or a composite cable capable of being used for electric communication and optical communication.

[0177] Here, although in the illustrated example, communication is performed by wired communication using the transmission cable 11400, communication between the camera 11102 and the CCU 11201 may be performed by wireless communication.

[0178] An example of an endoscopic surgical system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be appropriately applied to, for example, the imaging unit 11402 provided in the camera head 11102 of the endoscope 11100 in the above-mentioned configuration. Applying the technology according to the present disclosure to the imaging unit 11402 allows the imaging unit 11402 to have high sensitivity, providing the endoscope 11100 with high definition.

[0179] Although the embodiments, modifications, use examples, and applications of the present disclosure have been provided above, the present technology is not limited to the above embodiments, etc., and can be modified in various ways. For example, although the above modifications have been described as modifications of the above embodiments, the configurations of the modifications can be appropriately combined.

[0180] According to an embodiment of the present disclosure, a light detecting device includes: a first semiconductor layer including a light receiving element configured to receive light and output current; a groove disposed in the first semiconductor layer, the groove surrounding the light receiving element; a light shielding film disposed in the groove, the light shielding film comprising a metal material; and a first wiring disposed on the first surface side of the first semiconductor layer. The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type disposed on the first surface side of the first semiconductor layer. The first wiring includes polycrystalline silicon or amorphous silicon and electrically connects the first semiconductor region and the light shielding film. Thus, the light shielding film can be used as an anode wiring, so that the capacitance added to the cathode wiring will be reduced. This enables power consumption to be reduced.

[0181] Note that the effects described here are merely examples, and the effects are not limited to the descriptions thereof. Other effects may be exhibited. In addition, the present disclosure may have the following configurations. (1)

[0183] A light detection device, comprising:

[0184] a first semiconductor layer including a light receiving element configured to receive light and output current;

[0185] a groove provided in the first semiconductor layer, the groove surrounding the light receiving element;

[0186] A light-shielding film provided in the groove, the light-shielding film comprising a metal material; and

[0187] A first wiring is provided on the first surface side of the first semiconductor layer, wherein

[0188] The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer, and

[0189] The first wiring includes polysilicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film. (2)

[0191] The light detection device according to (1), wherein

[0192] The first semiconductor region includes a p-type semiconductor region, and

[0193] The second semiconductor region includes an n-type semiconductor region. (3)

[0195] The light detection device according to (1) or (2), wherein the first wiring is provided so as to cover the first semiconductor region and the light shielding film on the first surface side of the first semiconductor layer. (4)

[0197] The light detecting device according to any one of (1) to (3), wherein the first wiring is provided to surround the light receiving element. (5)

[0199] The light detection device according to any one of (1) to (4), further comprising a plurality of pixels, each pixel including the light receiving element, wherein

[0200] The first semiconductor region is provided at a corner of any one of the pixels. (6)

[0202] The light detection device according to any one of (1) to (5), further comprising a plurality of pixels each including the light receiving element, wherein

[0203] The first semiconductor region is provided at four corners of any one of the pixels. (7)

[0205] The photodetection device according to any one of (1) to (6), wherein the first wiring is directly connected to the first semiconductor region and the light shielding film. (8)

[0207] The light detecting device according to any one of (1) to (7), wherein a part of the first wiring is formed so as to be embedded in the first semiconductor layer and connects a side surface of the first semiconductor region and the light shielding film. (9)

[0209] The light detecting device according to any one of (1) to (8), further comprising an insulating layer provided on the first surface side of the first semiconductor layer, wherein

[0210] The first wiring is provided in the insulating layer. (10)

[0212] The light detecting device according to (9), further comprising a first through hole provided in the insulating layer and connecting the first wiring and the first semiconductor region, wherein

[0213] The first through hole comprises polysilicon or amorphous silicon, and

[0214] The light shielding film reaches the first wiring in the insulating layer. (11)

[0216] The light detection device according to any one of (1) to (10), wherein

[0217] The first semiconductor layer includes a first surface and a second surface opposite to the first surface, and

[0218] The trench and the light shielding film reach at least the second surface of the first semiconductor layer. (12)

[0220] The light detection device according to any one of (1) to (11), further comprising a pixel array provided with a plurality of pixels including the light receiving element, wherein

[0221] The first wiring extends to a region outside the pixel array. (13)

[0223] The light detection device according to any one of (1) to (12), further comprising:

[0224] a reading circuit configured to output a signal based on the current of the light receiving element, and

[0225] a second semiconductor layer stacked on the first semiconductor layer, wherein

[0226] The second semiconductor layer includes at least a portion of the readout circuit. (14)

[0228] The light detection device according to (13), further comprising:

[0229] an insulating layer disposed between the first semiconductor layer and the second semiconductor layer; and

[0230] a second wiring electrically connecting the second semiconductor region and the reading circuit, wherein

[0231] The second wiring extends in the insulating layer along a stacking direction of the first semiconductor layer and the second semiconductor layer. (15)

[0233] The light detection device according to (13) or (14), wherein

[0234] The first wiring is provided in the insulating layer, and

[0235] No wiring is provided between the first wiring and the second semiconductor layer. (16)

[0237] The light detection device according to any one of (13) to (15), further comprising:

[0238] a first semiconductor chip including the first semiconductor layer and the second semiconductor layer; and

[0239] A second semiconductor chip is stacked on the first semiconductor chip. (17)

[0241] The light detection device according to (16), wherein

[0242] The first semiconductor chip and the second semiconductor chip are stacked by bonding between electrodes, and

[0243] The electrodes connecting the first semiconductor chip and the second semiconductor chip have a pitch substantially equal to a pixel pitch. (18)

[0245] The photodetection device according to any one of (1) to (17), wherein the light receiving element includes a breakdown region that causes avalanche breakdown. (19)

[0247] The light detection device according to any one of (1) to (18), wherein the light receiving element includes a single photon avalanche diode. (20)

[0249] A distance measuring system, comprising:

[0250] a light source configured to apply light to a target object; and

[0251] a light detection device that receives light from the target object,

[0252] The light detection device comprises:

[0253] a first semiconductor layer including a light receiving element configured to receive light and output current;

[0254] a groove provided in the first semiconductor layer, the groove surrounding the light receiving element;

[0255] A light-shielding film provided in the groove, the light-shielding film comprising a metal material; and

[0256] a first wiring provided on the first surface side of the first semiconductor layer,

[0257] The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer, and

[0258] The first wiring includes polysilicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film.

[0259] This application claims priority from Japanese Patent Application JP2022-122172 filed with the Japan Patent Office on July 29, 2022, the entire contents of which are incorporated herein by reference.

[0260] It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made according to design requirements and other factors as long as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. A light detection device, comprising: a first semiconductor layer including a light receiving element configured to receive light and output current; a groove provided in the first semiconductor layer, the groove surrounding the light receiving element; a light shielding film disposed in the groove, the light shielding film comprising a metal material; and a first wiring provided on the first surface side of the first semiconductor layer, wherein the light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer, and The first wiring includes polysilicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film.

2. The light detection device according to claim 1, wherein The first semiconductor region includes a p-type semiconductor region, and The second semiconductor region includes an n-type semiconductor region. 3 . The light detecting device according to claim 1 , wherein the first wiring is provided so as to cover the first semiconductor region and the light shielding film on the first surface side of the first semiconductor layer. 4 . The light detecting device according to claim 1 , wherein the first wiring is provided so as to surround the periphery of the light receiving element.

5. The light detection device according to claim 1, comprising a plurality of pixels, each pixel comprising the light receiving element, wherein The first semiconductor region is provided at a corner of the pixel.

6. The light detection device according to claim 1, further comprising a plurality of pixels each including the light receiving element, wherein The first semiconductor regions are disposed at four corners of the pixel. 7 . The light detecting device according to claim 1 , wherein the first wiring is directly connected to the first semiconductor region and the light shielding film. 8 . The light detecting device according to claim 1 , wherein a part of the first wiring is formed so as to be embedded in the first semiconductor layer and connect a side surface of the first semiconductor region and the light shielding film.

9. The light detecting device according to claim 1, further comprising an insulating layer provided on the first surface side of the first semiconductor layer, wherein The first wiring is provided in the insulating layer.

10. The light detecting device according to claim 9, further comprising a first through hole provided in the insulating layer and connecting the first wiring and the first semiconductor region, wherein The first through hole comprises polysilicon or amorphous silicon, and The light shielding film reaches the first wiring in the insulating layer.

11. The light detection device according to claim 1, wherein The first semiconductor layer includes a first surface and a second surface opposite to the first surface, and The trench and the light shielding film reach at least the second surface of the first semiconductor layer.

12. The light detection device according to claim 1, further comprising a pixel array provided with a plurality of pixels including the light receiving element, wherein The first wiring extends to a region outside the pixel array.

13. The light detection device according to claim 1, further comprising: a reading circuit configured to output a signal based on the current of the light receiving element, and a second semiconductor layer stacked on the first semiconductor layer, wherein The second semiconductor layer includes at least a portion of the readout circuit.

14. The light detection device according to claim 13, further comprising: an insulating layer disposed between the first semiconductor layer and the second semiconductor layer; and a second wiring electrically connecting the second semiconductor region and the reading circuit, wherein The second wiring extends in the insulating layer along a stacking direction of the first semiconductor layer and the second semiconductor layer.

15. The light detection device according to claim 14, wherein The first wiring is provided in the insulating layer, and No wiring is provided between the first wiring and the second semiconductor layer.

16. The light detection device according to claim 13, further comprising: A first semiconductor chip comprising the first semiconductor layer and the second semiconductor layer; and A second semiconductor chip is stacked on the first semiconductor chip.

17. The light detection device according to claim 16, wherein The first semiconductor chip and the second semiconductor chip are stacked by bonding between electrodes, and A pitch between electrodes connecting the first semiconductor chip and the second semiconductor chip is substantially equal to a pixel pitch. 18 . The light detecting device according to claim 1 , wherein the light receiving element includes a breakdown region that enables avalanche breakdown.

19. The light detecting device according to claim 1, wherein the light receiving element comprises a single photon avalanche diode.

20. A distance measurement system, comprising: a light source configured to apply light to a target object; and a light detection device that receives light from the target object, The light detection device comprises: a first semiconductor layer including a light receiving element configured to receive light and output current; a groove provided in the first semiconductor layer, the groove surrounding the light receiving element; A light shielding film disposed in the groove, the light shielding film comprising a metal material; and a first wiring provided on the first surface side of the first semiconductor layer, The light receiving element includes a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type provided on the first surface side of the first semiconductor layer, and The first wiring includes polysilicon or amorphous silicon, and electrically connects the first semiconductor region and the light shielding film.

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