Semiconductor element and electronic device

Abstract

The present technology relates to a semiconductor element and an electronic device with which it is possible to stabilize circuit operation without increasing the circuit area in a substrate in which a second-conductivity type semiconductor region is formed between a plurality of first-conductivity type semiconductor regions arranged side by side in a planar direction. A plurality of N-wells arranged in a planar direction, P-wells formed between the N-wells, and an FTI for separating the N-wells and the P-wells are formed on a substrate of a photo detection element. A conduction part for electrically connecting the N-wells to each other is formed in the P-wells. The present technology can be applied to, for example, a photo detection element having layered therein: a substrate in which pixel sensor units having SPADs as light-receiving elements are two-dimensionally arranged in a matrix in the row direction and the column direction; a substrate having a readout circuit; and a substrate having a signal processing circuit.

Description

Semiconductor devices and electronic devices

[0001] The present technology relates to a semiconductor element and an electronic device, and in particular to a semiconductor element and an electronic device that are capable of stabilizing circuit operation without increasing the circuit area in a substrate in which a semiconductor region of a second conductivity type is formed between a plurality of semiconductor regions of a first conductivity type that are aligned in a planar direction.

[0002] There is a semiconductor device that forms an imaging LSI (Large Scale Integration) by sequentially stacking a first substrate having photodiode pixels, a second substrate having a readout circuit, and a third substrate having a logic circuit (see, for example, Patent Document 1). In such a semiconductor device, the only transistor included in the readout circuit is an N-type MOSFET (metal-oxide-semiconductor field-effect transistor). Therefore, the readout circuit can be formed solely using a P-well, which is a P-type semiconductor region.

[0003] On the other hand, there are semiconductor devices that form a distance measurement LSI by stacking a first substrate having SPAD (Single Photon Avalanche Diode) pixels and a second substrate having a readout circuit (see, for example, Patent Document 2). In such semiconductor devices, the readout circuit is a CMOS circuit in which P-type MOSFETs and N-type MOSFETs are complementarily combined. Therefore, in the substrate having the readout circuit, multiple P-wells and N-wells, which are N-type semiconductor regions, are arranged in the planar direction, and one of them is formed between the other, requiring separation between the P-wells and N-wells. In the semiconductor device described in Patent Document 2, a PN junction is used to separate the P-wells and N-wells.

[0004] International Publication No. 2019 / 130702 Japanese Patent Application Laid-Open No. 2004-8923

[0005] In a substrate with a CMOS circuit, where multiple P-wells and N-wells are arranged in a plane and one of them is formed between the other, at least one of the P-wells and N-wells is separated in the plane, resulting in a floating state. Since circuit operation becomes unstable when a well is in a floating state, it is necessary to connect the wells using metal wiring. Therefore, the layout of the metal wiring increases the circuit size.

[0006] Therefore, in a substrate in which one of a plurality of P wells and N wells arranged in a planar direction is formed between the other, there is a demand for a method of stabilizing circuit operation without increasing the circuit area, but at present such demand has not been adequately met.

[0007] The present technology has been developed in consideration of such circumstances, and makes it possible to stabilize circuit operation without increasing the circuit area in a substrate in which a semiconductor region of a second conductivity type is formed between multiple semiconductor regions of a first conductivity type that are arranged in a planar direction.

[0008] A semiconductor element according to a first aspect of the present technology is a semiconductor element including a first substrate on which are formed a plurality of semiconductor regions of a first conductivity type arranged in a planar direction, semiconductor regions of a second conductivity type formed between the semiconductor regions of the first conductivity type, first separation walls separating the semiconductor regions of the first conductivity type from the semiconductor regions of the second conductivity type, and conductive portions formed in the semiconductor regions of the second conductivity type to electrically connect the semiconductor regions of the first conductivity type to each other.

[0009] In a first aspect of the present technology, a first substrate is provided, the first substrate having formed thereon a plurality of semiconductor regions of a first conductivity type aligned in a planar direction, semiconductor regions of a second conductivity type formed between the semiconductor regions of the first conductivity type, first separation walls separating the semiconductor regions of the first conductivity type and the semiconductor regions of the second conductivity type, and conductive portions formed in the semiconductor regions of the second conductivity type and electrically connecting the semiconductor regions of the first conductivity type to each other.

[0010] An electronic device according to a second aspect of the present technology includes a light source unit that outputs irradiated light and a semiconductor element that receives reflected light that is generated when the irradiated light is reflected by an object, and the semiconductor element includes a first substrate on which light-receiving elements that receive the reflected light are arranged two-dimensionally in a matrix form, and a second substrate on which a readout circuit that reads out a signal corresponding to the light detected by the light-receiving elements is formed, and the second substrate is provided with a plurality of first-conductivity-type semiconductor regions aligned in a planar direction, second-conductivity-type semiconductor regions formed between the first-conductivity-type semiconductor regions, a first separation wall that separates the first-conductivity-type semiconductor regions and the second-conductivity-type semiconductor regions, and a conductive portion that is formed in the second-conductivity-type semiconductor region and electrically connects the first-conductivity-type semiconductor regions to each other.

[0011] In a second aspect of the present technology, a light source unit that outputs irradiation light and a semiconductor element that receives reflected light that is generated when the irradiation light is reflected by an object are provided, the semiconductor element including a first substrate on which light-receiving elements that receive the reflected light are two-dimensionally arranged in a matrix, and a second substrate on which a readout circuit that reads out a signal corresponding to light detected by the light-receiving elements is formed, the second substrate including a plurality of first-conductivity-type semiconductor regions arranged in a planar direction, a second-conductivity-type semiconductor region formed between the first-conductivity-type semiconductor regions, a first separation wall that separates the first-conductivity-type semiconductor region from the second-conductivity-type semiconductor region, and a conductive portion formed in the second-conductivity-type semiconductor region that electrically connects the first-conductivity-type semiconductor regions to each other.

[0012] The semiconductor device and electronic device may be an independent device or a module to be incorporated into another device.

[0013] Fig. 1 is a block diagram showing an example of the configuration of an electronic device equipped with a photodetector element to which the present technology is applied; Fig. 2 is a cross-sectional view showing an example of the configuration of a substrate of a photodetector element; Fig. 3 is a diagram showing an example of the structure of a substrate; Fig. 4 is a diagram explaining a method for manufacturing a photodetector element; Fig. 5 is a block diagram showing an example of the schematic configuration of a vehicle control system; Fig. 6 is an explanatory diagram showing an example of the installation position of an imaging unit;

[0014] Hereinafter, with reference to the accompanying drawings, a description will be given of a mode for carrying out the present technology (hereinafter referred to as an embodiment). The description will be made in the following order: 1. One embodiment 2. Application example to a moving body

[0015] In the drawings referred to in the following description, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc. may differ from the actual ones. Furthermore, the drawings may include parts whose dimensional relationships and ratios differ from each other.

[0016] Furthermore, the definitions of directions such as up and down in the following description are merely for the convenience of explanation and do not limit the technical idea of ​​the present disclosure. For example, if an object is rotated 90 degrees and observed, up and down are converted to left and right and read, and if it is rotated 180 degrees and observed, up and down are read inverted.

[0017] 1. One Embodiment Configuration Example of Electronic Device FIG. 1 is a block diagram showing a configuration example of one embodiment of an electronic device equipped with a photodetector element to which the present technology is applied.

[0018] The electronic device 1 includes a distance measuring device 11 and an application unit 12. The distance measuring device 11 directly measures the distance to a measurement target object (measurement target) 30 using a ToF (Time of Flight) method and outputs distance information, which is the measurement result, to the application unit 12. The distance information is, for example, configured as a depth image in which a depth value indicating the distance to the subject is stored as the pixel value of each pixel. The application unit 12 is realized, for example, by a program running on a CPU (Central Processing Unit), requests the distance measuring device 11 to perform distance measurement, and obtains distance information, which is the distance measurement result, from the distance measuring device 11. Examples of the electronic device 1 include devices mounted on smartphones, tablets, wearable devices, cameras such as in-vehicle cameras, digital still cameras, and digital video cameras, as well as devices mounted on mobile objects such as automobiles and drones.

[0019] The distance measuring device 11 includes a control unit 21, a light source unit 22, and a photodetector element 23. The control unit 21 includes control circuits and processors such as a field programmable gate array (FPGA) and a digital signal processor (DSP), and controls the overall operation of the distance measuring device 11. For example, the control unit 21 generates a reference clock signal that serves as a basis for clock signals used by each unit of the distance measuring device 11, and supplies the reference clock signal to the light source unit 22 and the photodetector element 23. In addition, the control unit 21 instructs the photodetector element 23 to perform distance measurement in response to a distance measurement execution request from the application unit 12, obtains distance information, which is the distance measurement result, from the photodetector element 23, and outputs the distance information to the application unit 12.

[0020] The light source unit 22 includes a light-emitting element that emits light with a wavelength in the infrared region, for example, and a drive circuit that drives the light-emitting element. The light-emitting element that emits light with a wavelength in the infrared region can be, for example, a light-emitting diode (LED). The light-emitting element is not limited to this, and can also be, for example, a vertical cavity surface-emitting laser (VCSEL), in which a plurality of light-emitting elements are arranged in an array. The light-emitting element of the light source unit 22 outputs irradiation light 31 based on a light-emission timing signal supplied from the photodetector element 23. The light-emission timing signal is, for example, a pulse signal modulated into a rectangular wave with a predetermined duty ratio. Hereinafter, unless otherwise specified, "the light-emitting element of the light source unit 22 emits light" will be expressed as "the light source unit 22 emits light," etc.

[0021] The photodetector element 23 is a semiconductor element that includes a SPAD as a light-receiving element that can detect light with wavelengths in the infrared region, a readout circuit that reads out a signal corresponding to the light detected by the light-receiving element, and a signal processing circuit that processes the signal. Hereinafter, unless otherwise specified, "the SPAD of the photodetector element 23 detects light" will be expressed as "the photodetector element 23 receives light," etc.

[0022] The photodetector element 23 executes distance measurement processing in response to a distance measurement execution instruction from the control unit 21. For example, the photodetector element 23 generates a light emission timing signal indicating the timing at which the light source unit 22 emits light, and supplies the light source unit 22 with the signal. The photodetector element 23 also performs a light receiving operation in synchronization with the light emission timing signal and measures a count value that serves as the basis for calculating a depth value. The count value is a count value obtained by counting the time from when the light source unit 22 outputs irradiation light 31 to when the photodetector element 23 receives reflected light 32 from the object 30. The photodetector element 23 supplies the count value to the control unit 21, for example, as distance information. Alternatively, the photodetector element 23 may calculate and generate a distance D to the object 30 from the count value, and store the calculated depth image as a depth value and supply the stored depth image to the control unit 21 as distance information. The control unit 21 may perform the process of generating a depth image based on the count value.

[0023] <Example of substrate configuration of photodetector element> FIG. 2 is a cross-sectional view showing an example of the substrate configuration of the photodetector element 23 in FIG.

[0024] 2, the photodetector element 23 has a layered structure in which substrates 51 to 53 are stacked in this order. The substrates 51 and 52 are bonded via an insulating film layer 54, and the substrates 52 and 53 are bonded via an insulating film layer 54. The lower surface of the substrate 51 is the light incident surface, and the reflected light 32 is incident on the substrate 51 from below.

[0025] Pixel sensor units are arranged two-dimensionally in a matrix in the row and column directions on the substrate 51 (pixel substrate). The pixel sensor units have, for example, SPADs, and output detection signals indicating the results of detecting the reflected light 32.

[0026] The substrate 52 is provided with readout circuits, each composed of a CMOS circuit, in one-to-one correspondence with the pixel sensor units. Each readout circuit is electrically connected to its corresponding pixel sensor unit by a through-wire 54a formed in the insulating film layer 54. Note that, for the sake of simplicity, only one through-wire 54a is shown in FIG. 2, but in reality, there are as many through-wires 54a as there are pixel sensor units.

[0027] The substrate 53 (logic substrate) is electrically connected to the substrate 52 by through-wiring 55a formed in the metal wiring layer 55. The substrate 53 is provided with a signal processing circuit.

[0028] The insulating film layer 54 includes metal wiring such as through-hole wiring 54a and an insulating film 54b such as an SiO2 film. The metal wiring layer 55 includes metal wiring such as through-hole wiring 55a and an insulating film 55b such as an SiO2 film. The insulating film layer 54 and the metal wiring layer 55 may be multi-layered.

[0029] <Structural Example of Substrate 52> Figure 3 is a diagram showing a structural example of the substrate 52 of Figure 2. Specifically, Figure 3A is a top view of a portion of the substrate 52. Figure 3B is a cross-sectional view taken along line A-A of Figure 3A, and Figure 3C is a cross-sectional view taken along line B-B of Figure 3A.

[0030] 3, two N-wells 71-1 and 71-2 aligned in the planar direction of the substrate 52 are formed in the substrate 52, and a P-well 72 is formed between the N-wells 71-1 and 71-2. Specifically, the substrate 52 is a P-type silicon substrate in which the N-wells 71-1 and 71-2 are formed by being separated into island shapes. Note that, hereinafter, when there is no need to particularly distinguish between the N-wells 71-1 and 71-2, they will be collectively referred to as the N-well 71.

[0031] A P-type MOSFET 80 included in the readout circuit is formed in the N-well 71. In the example of FIG. 3, two P-type MOSFETs 80 are formed in each N-well 71. Each P-type MOSFET 80 is composed of two P-type semiconductor regions 81 formed in the N-well 71 and a gate electrode 82 formed on the N-well 71 between the two P-type semiconductor regions 81. A shallow trench isolation (STI) 83, which is an insulating region that does not penetrate the substrate 52, is formed between the two P-type MOSFETs 80. Note that the STI 83 is not shown in FIG. 3A to make the drawing easier to understand.

[0032] An N-type MOSFET 90 included in the read circuit is formed in the P-well 72. In the example of FIG. 3, two N-type MOSFETs 90 are formed in each P-well 72. Each N-type MOSFET 90 is composed of two N-type semiconductor regions 91 formed in the P-well 72 and a gate electrode 92 formed on the P-well 72 between the two N-type semiconductor regions 91. An STI 93 (third isolation wall), which is an insulating region that does not penetrate the substrate 52, is formed between the two N-type MOSFETs 90. Note that the STI 93 is not shown in FIG. 3A to make the drawing easier to understand.

[0033] Also formed in the substrate 52 is an insulating region, a full trench isolation (FTI) (first isolation wall) 73, which separates the N-well 71 and the P-well 72. The FTI 73 is formed to penetrate the substrate 52 or the region below the STI 83.

[0034] A conductive portion 74 is formed in the P well 72 to electrically connect the N wells 71 to each other so as to penetrate the region below the STI 93. An FTI 75 (second isolation wall) is formed between the conductive portion 74 and the P well 72.

[0035] <Description of Manufacturing Method> FIG. 4 is a diagram illustrating a manufacturing method of the light detection element 23. As shown in FIG.

[0036] First, a substrate 51 is formed, and an insulating film layer 54 is formed on the substrate 51. Next, as shown in Fig. 4A, a P-type silicon substrate 120 having a thickness of, for example, about 500 nm is laminated on the insulating film layer 54.

[0037] 4B, a resist 121 is applied (patterned) to the P-type silicon substrate 120 in areas other than the areas where the STIs 83 and 93 are to be formed. The areas where the resist 121 is not applied are then etched to form grooves 122 of, for example, about 300 nm. Thereafter, the resist 121 is removed.

[0038] 4C, resist 123 is applied (patterned) to the region where N well 71 is to be formed and the region other than the trench 122 corresponding to the STI 93 below which the conductive portion 74 is to be formed. Then, N well 71 is formed in the region where N well 71 is to be formed and where resist 123 is not applied. Phosphorus (P) ions are implanted into the bottom of the trench 122 corresponding to the STI 93 below which the conductive portion 74 is to be formed, thereby forming an N+ region as the conductive portion 74. Thereafter, resist 123 is removed.

[0039] 4D, resist 124 is applied (patterned) to regions other than the regions where FTIs 73 and 75 are to be formed. The regions where resist 124 is not applied are then etched to form grooves 125 that reach the bottom surface of P-type silicon substrate 120. Thereafter, resist 124 is removed.

[0040] 4E, a SiO2 film (silicon oxide film) is deposited in the grooves 122 corresponding to the STIs 83 and 93 and the grooves 125 corresponding to the FTIs 73 and 75. This forms the STIs 83 and 93 and the FTIs 73 and 75. Then, the substrate is polished by CMP (Chemical Mechanical Polishing) until the P-type silicon substrate 120 is exposed.

[0041] 4F, a P-type semiconductor region 81, a gate electrode 82, an N-type semiconductor region 91, and a gate electrode 92 are formed to form a P-type MOSFET 80 and an N-type MOSFET 90. In this manner, the substrate 52 is formed.

[0042] Thereafter, although not shown, a metal wiring layer 55 is formed on the upper surface of the substrate 52 on which the P-type MOSFET 80 and the N-type MOSFET 90 have been formed. Then, the substrate 53 is laminated on the metal wiring layer 55. In this manner, the photodetector element 23 is manufactured.

[0043] As described above, the substrate 52 of the photodetector element 23 is formed with a plurality of N wells 71 arranged in the planar direction, P wells 72 formed between the N wells 71, and FTIs 73 separating the N wells 71 and P wells 72. Conductive portions 74 that electrically connect the N wells 71 to each other are formed in the P wells 72. Therefore, the potential between the N wells 71 can be stabilized via the conductive portions 74 without using metal wiring. As a result, the space efficiency of the circuit layout is improved, and circuit operation can be stabilized without increasing the circuit area of ​​the photodetector element 23.

[0044] In the above example, the substrate 52 is formed using a P-type silicon substrate 120, but it may also be formed using an N-type silicon substrate. In this case, the aforementioned semiconductor regions are configured with semiconductor regions of the opposite conductivity type, and the same effect can be obtained.

[0045] The present technology can also be applied to semiconductor elements other than photodetector elements.

[0046] 2. Application Examples to Mobile Bodies The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0047] FIG. 5 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.

[0048] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 5, 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 in the figure are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053 as functional components of the integrated control unit 12050.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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 distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0055] 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.

[0056] 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.

[0057] 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. 5, 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.

[0058] FIG. 6 is a diagram showing an example of the installation position of the imaging unit 12031.

[0059] In FIG. 6, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0060] 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.

[0061] 6 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.

[0062] 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.

[0063] 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 allows the vehicle to travel autonomously without relying on driver operation.

[0064] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0065] 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.

[0066] The above describes an example of a vehicle control system to which the technology disclosed herein can be applied. The technology disclosed herein can be applied to the imaging unit 12031 and other components of the above-described configuration. Specifically, the electronic device 1 or the ranging device 11 shown in FIG. 1 can be used as the imaging unit 12031 to realize, for example, a LiDAR (Light Detection and Ranging) system that detects objects around the vehicle 12100 and the distance to the objects. By applying the technology disclosed herein to the imaging unit 12031, circuit operation can be stabilized without increasing the circuit area of ​​the imaging unit 12031. This improves the accuracy of detecting objects around the vehicle 12100 and the distance to the objects. As a result, for example, a vehicle collision warning can be issued at an appropriate time, making it possible to prevent traffic accidents.

[0067] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present technology.

[0068] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0069] The present technology can have the following configurations. (1) A semiconductor element including a first substrate on which are formed a plurality of first conductivity type semiconductor regions arranged in a planar direction, a second conductivity type semiconductor region formed between the first conductivity type semiconductor regions, a first isolation wall separating the first conductivity type semiconductor region and the second conductivity type semiconductor region, and a conductive portion formed in the second conductivity type semiconductor region and electrically connecting the first conductivity type semiconductor regions to each other. (2) The semiconductor element according to (1), configured such that a second isolation wall is formed between the conductive portion and the second conductivity type semiconductor region. (3) The semiconductor element according to (2), configured such that the conductive portion is formed so as to penetrate a region below a third isolation wall formed between the first conductivity type semiconductor regions in the second conductivity type semiconductor region. (4) The semiconductor element according to any of (1) to (3), configured such that the first isolation wall penetrates the first substrate. (5) The semiconductor device according to any one of (1) to (4), further comprising a second substrate electrically connected to the first substrate by through-hole wiring, wherein the first substrate and the second substrate are bonded via an insulating film. (6) The semiconductor device according to (5), wherein light-receiving elements are two-dimensionally arranged in a matrix on the second substrate, and wherein a readout circuit for reading out signals corresponding to light detected by the light-receiving elements is formed on the first substrate. (7) The semiconductor device according to (6), wherein the readout circuit includes a MOSFET. (8) The semiconductor device according to (7), wherein the readout circuit is formed of a CMOS circuit. (9) The semiconductor device according to any one of (6) to (8), further comprising a third substrate electrically connected to the first substrate by through-hole wiring, wherein a signal processing circuit for processing the signals read out by the readout circuit is formed on the third substrate, and wherein the first substrate and the third substrate are bonded via an insulating film.(10) An electronic device comprising: a light source unit that outputs irradiated light; and a semiconductor element that receives reflected light of the irradiated light reflected by an object, wherein the semiconductor element has a first substrate on which light-receiving elements that receive the reflected light are arranged two-dimensionally in a matrix form; and a second substrate on which a readout circuit that reads out a signal corresponding to the light detected by the light-receiving elements is formed, wherein the second substrate is formed with: a plurality of first-conductivity-type semiconductor regions aligned in a planar direction; second-conductivity-type semiconductor regions formed between the first-conductivity-type semiconductor regions; a first separation wall that separates the first-conductivity-type semiconductor regions from the second-conductivity-type semiconductor regions; and a conductive portion formed in the second-conductivity-type semiconductor region that electrically connects the first-conductivity-type semiconductor regions to each other.

[0070] 1 Electronic device, 22 Light source unit, 23 Photodetector element, 51 to 53 Substrate, 54a, 55a Through wiring, 54b, 55b Insulating film, 71-1, 71-2 N well, 72 P well, 73 FTI, 74 Conduction portion, 75 FTI, 91 N-type semiconductor region, 93 STI

Claims

1. A semiconductor device comprising a first substrate having formed thereon a plurality of semiconductor regions of a first conductivity type arranged in a planar direction, semiconductor regions of a second conductivity type formed between the semiconductor regions of the first conductivity type, first separation walls separating the semiconductor regions of the first conductivity type from the semiconductor regions of the second conductivity type, and conductive parts formed in the semiconductor regions of the second conductivity type that electrically connect the semiconductor regions of the first conductivity type to each other.

2. The semiconductor device according to claim 1, wherein a second separation wall is formed between the conductive portion and the second conductivity type semiconductor region.

3. The semiconductor element according to claim 2, wherein the conductive portion is configured to be formed so as to penetrate a region below a third isolation wall formed between the semiconductor regions of the first conductivity type within the semiconductor region of the second conductivity type.

4. The semiconductor device according to claim 1, wherein the first separation wall is configured to penetrate the first substrate.

5. The semiconductor device according to claim 1, further comprising a second substrate electrically connected to the first substrate by a through-wiring, the first substrate and the second substrate being bonded together via an insulating film.

6. A semiconductor device according to claim 5, wherein light receiving elements are arranged two-dimensionally in a matrix on the second substrate, and a readout circuit is formed on the first substrate for reading out signals corresponding to the light detected by the light receiving elements.

7. The semiconductor device according to claim 6, wherein the readout circuit is configured to include a MOSFET.

8. The semiconductor device according to claim 7, wherein the readout circuit is configured as a CMOS circuit.

9. The semiconductor device according to claim 6, further comprising a third substrate electrically connected to the first substrate by through-wiring, wherein a signal processing circuit for processing the signal read by the readout circuit is formed on the third substrate, and wherein the first substrate and the third substrate are bonded via an insulating film.

10. Electronic equipment comprising: a light source unit that outputs irradiated light; and a semiconductor element that receives reflected light when the irradiated light is reflected by an object, wherein the semiconductor element has a first substrate on which light-receiving elements that receive the reflected light are arranged two-dimensionally in a matrix, and a second substrate on which a readout circuit that reads out a signal corresponding to the light detected by the light-receiving elements is formed, wherein the second substrate is formed with: a plurality of first conductivity type semiconductor regions arranged in a planar direction; second conductivity type semiconductor regions formed between the first conductivity type semiconductor regions; first separation walls that separate the first conductivity type semiconductor regions and the second conductivity type semiconductor regions; and a conductive portion formed in the second conductivity type semiconductor region that electrically connects the first conductivity type semiconductor regions to each other.

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