WO2022102549A1 - Solid-state imaging device - Google Patents

Abstract

[Problem] To make it possible to expand dynamic range, even if pixel structure is downsized. [Solution] A solid-state imaging device that comprises a first semiconductor layer that includes a first-conduction-type first compound semiconductor material, a photoelectric conversion layer that is arranged above the first semiconductor layer, a second-conduction-type second semiconductor layer that is partially arranged above the photoelectric conversion layer and contacts the photoelectric conversion layer, and an element separation layer that separates the first semiconductor layer, the photoelectric conversion layer, and the second semiconductor layer pixel by pixel. The pixels include subpixels that have different sizes and sensitivities.

Description

Solid-state image sensor

This disclosure relates to a solid-state image sensor.

A light receiving element array that can receive light up to a long wavelength region in the near infrared and can secure light receiving sensitivity even if the pixel pitch is dense has been proposed (see Patent Document 1). Patent Document 1 discloses a light receiving element array in which a plurality of light receiving portions having a bandgap energy corresponding to a near infrared wavelength region are arranged. The light receiving portion of this light receiving element array has a pn junction at the tip of the p-shaped region formed by selective diffusion, and an n-shaped region is provided between the light receiving portions to divide the light receiving portion for each pixel. There is.

Japanese Unexamined Patent Publication No. 2012-244124

Since the light receiving element array disclosed in Patent Document 1 has the same light receiving sensitivity for each pixel, if the pixel structure is miniaturized, the light receiving sensitivity is lowered as a whole and the dynamic range cannot be widened.

Therefore, the present disclosure provides a solid-state image sensor capable of expanding the dynamic range even if the pixel structure is miniaturized.

In order to solve the above problems, according to the present disclosure, a first semiconductor layer having a first conductive type first compound semiconductor material and a first semiconductor layer
The photoelectric conversion layer arranged on the first semiconductor layer and
A second conductive type second semiconductor layer partially arranged on the photoelectric conversion layer and arranged so as to be in contact with the photoelectric conversion layer.
The first semiconductor layer, the photoelectric conversion layer, and the element separation layer for separating the second semiconductor layer on a pixel-by-pixel basis are provided.
A solid-state image sensor is provided in which the pixels have a plurality of sub-pixels having different sensitivities and sizes.

The second semiconductor layer has a plurality of well regions separated from each other corresponding to each of the plurality of subpixels.
The plurality of well regions may have different sizes.

The plurality of well regions may have different areas when viewed in a plan view along the stacking direction of the second semiconductor layer.

The plane sizes of the plurality of well regions may be different from each other.

The plurality of well regions may be arranged in the corresponding pixels so as to be oriented in the same direction.

The plurality of well regions may be arranged in different directions in the corresponding pixels.

A light-shielding layer arranged in at least a part of the element separation layer may be provided.

The light-shielding layer may be arranged at the boundary position of the pixel.

The light-shielding layer may be arranged at the boundary position of each of the plurality of sub-pixels in the pixel.

The light-shielding layer may be arranged so as to surround each of the plurality of sub-pixels when viewed in a plan view along the stacking direction of the second semiconductor layer.

The areas of the plurality of sub-pixels surrounded by the light-shielding layer in the pixels in a plan view along the stacking direction may be different from each other.

A light-shielding layer arranged at the boundary position of each of the plurality of sub-pixels in the pixel is provided.
The plurality of well regions may be regions separated by the light-shielding layer.

The areas of the plurality of sub-pixels divided by the light-shielding layer in the pixels in a plan view along the stacking direction are different from each other.
The areas of the plurality of well regions in the pixel viewed in a plane along the stacking direction may be the same.

The photoelectric conversion layer of the plurality of subpixels in the pixel may contain a different material for each subpixel.

The material may contain InGaAs or CuInGaSe ₂ .

A third semiconductor layer arranged on the photoelectric conversion layer and having the first conductive type second compound semiconductor material is provided.
The second semiconductor layer may be arranged on the third semiconductor layer.

The plan layout view of the solid-state image sensor according to 1st Embodiment. FIG. 1A is a cross-sectional view in the diagonal direction. The block diagram which shows the schematic structure of the solid-state image sensor according to this embodiment. A plane layout diagram in which the first subpixel and the second subpixel are arranged in each pixel P with different orientations. The plan layout view of the solid-state image sensor according to the 2nd Embodiment. FIG. 4A is a cross-sectional view in the diagonal direction. The plan layout view of the solid-state image sensor according to the 3rd Embodiment. A circuit diagram showing an example of a readout circuit. The operation timing diagram and the potential diagram of the readout circuit of FIG. The potential diagram of the time following FIG. 7A. The potential diagram of the time following FIG. 7B. The potential diagram of the time following FIG. 7C. The potential diagram of the time following FIG. 7D. A block diagram showing an example of a schematic configuration of a vehicle control system. Explanatory drawing which shows an example of the installation position of the outside information detection unit and the image pickup unit.

Hereinafter, embodiments of the solid-state image sensor will be described with reference to the drawings. In the following, the main components of the solid-state image sensor will be mainly described, but the solid-state image sensor may have components and functions not shown or described. The following description does not exclude components or functions not shown or described.

(First Embodiment)
Since the bandgap energy of silicon is 1.1 eV, a solid-state image pickup device using silicon as a base substrate cannot detect infrared light having a wavelength longer than 1.1 μm. On the other hand, in the group III-V compound semiconductor, the bandgap energy corresponds to the near infrared wavelength region. Therefore, the solid-state image sensor according to the present embodiment uses a group III-V compound semiconductor as a base substrate to enable image pickup of near-infrared light.

FIG. 1A is a plan layout view of the solid-state image sensor 1 according to the first embodiment, and FIG. 1B is a cross-sectional view in the diagonal direction of FIG. 1A. Note that FIGS. 1A and 1B schematically show the characteristic portions of the solid-state image sensor 1 according to the present embodiment, and some members are omitted or simplified. Also, the horizontal and vertical size ratios in FIGS. 1A and 1B may differ from the actual solid-state image sensor 1.

The base substrate 2 of the solid-state imaging device 1 according to the present embodiment is a substrate made of a group III-V semiconductor such as GaAs, InP, GaN, AlN, GaP, GaSb, InSb, and InAs.

As shown in FIG. 1B, a first semiconductor layer (hereinafter, also referred to as a first compound semiconductor layer) 3 having a first conductive type (for example, n-type) first compound semiconductor material is arranged on the substrate 2. ing. The first semiconductor layer 3 is made of, for example, InP (specifically, n-InP).

The photoelectric conversion layer 4 is arranged on the first semiconductor layer 3. The photoelectric conversion layer 4 is made of, for example, InGaAs (specifically, n-InGaAs).

A third semiconductor layer 5 having a second compound material is arranged on the photoelectric conversion layer 4. The third semiconductor layer 5 is made of, for example, InP (specifically, n-InP). The third semiconductor layer 5 may be omitted.

In the present specification, the laminated first semiconductor layer 3, photoelectric conversion layer 4, and third semiconductor layer 5 are referred to as photoelectric conversion units 6. A plurality of photoelectric conversion units 6 are arranged in the plane direction of the substrate 2, and an element separation layer 7 is arranged between two adjacent photoelectric conversion units 6. Further, a semiconductor layer made of the same material as the element separation layer 7 is also arranged on the third semiconductor layer 5.

The element separation layer 7 is made of, for example, InP (specifically, n-InP). For example, by making the impurity concentration of the element separation layer 7 higher than the impurity concentration of the photoelectric conversion layer 4, the energy gap of the element separation layer 7 can be made wider than that of the photoelectric conversion layer 4.

Further, a second conductive type (for example, p-type) second semiconductor layer 8 is arranged on each photoelectric conversion unit 6. The second semiconductor layer 8 is partially arranged on the corresponding photoelectric conversion unit 6. The second semiconductor layer 8 is, for example, a region in which p-type impurity ions (for example, Zn ions) are selectively diffused in a semiconductor layer made of the same material as the device separation layer 7. In the present specification, the partially arranged second semiconductor layer 8 may be referred to as a well region. As shown in FIG. 1A, a plurality of well regions having different sizes are arranged on the photoelectric conversion layer 4. The areas of the plurality of well regions in the pixel P are different when viewed in a plan view along the stacking direction of the second semiconductor layer 8. The plane sizes of the plurality of well regions in the pixel P are different from each other.

The first electrode layer 9 is arranged on the second semiconductor layer 8. Further, the second electrode layer 10 is partially arranged on the element separation layer 7. The periphery of the first electrode layer 9 and the second electrode layer 10 is covered with a coating layer 11 made of an insulating material.

The first electrode layer 9 and the second electrode layer 10 are connected to the drive substrate 13 by a joining member 12 such as a bump, a Cu—Cu joint, or a via. A read circuit, a signal processing circuit, and the like are arranged on the drive board 13.

A flattening layer 14 is arranged on a surface of the base substrate 2 opposite to the surface on which the photoelectric conversion portion 6 is formed, and a microlens 15 is arranged on the flattening layer 14. In the solid-state image sensor 1 according to the present embodiment, the light incident through the microlens 15 is photoelectrically converted by the photoelectric conversion unit 6. The microlens 15 is arranged on the back surface side, and the solid-state image sensor 1 according to the present embodiment is a back-illuminated type.

The broken line frame shown in FIG. 1B indicates the boundary of the pixel P. An element separation layer 7 is provided at the boundary of the pixel P. The solid-state image sensor 1 according to the present embodiment has a plurality of sub-pixels having different sensitivities and sizes for each pixel P. 1A and 1B show an example in which one pixel P has two subpixels (hereinafter, referred to as a first subpixel SP1 and a second subpixel SP2). The number of sub-pixels provided in one pixel P is not limited to two, and may be three or more, but in the present specification, two sub-pixels (th) in one pixel P. An example having one subpixel SP1 and a second subpixel SP2) will be mainly described.

1A and 1B show an example in which the size of the first subpixel SP1 is larger than the size of the second subpixel SP2. Here, the size refers to the volume of the photoelectric conversion unit 6 in the first subpixel SP1 and the second subpixel SP2. That is, in FIGS. 1A and 1B, the volume of the photoelectric conversion unit 6 in the first subpixel SP1 is larger than the volume of the photoelectric conversion unit 6 in the second subpixel SP2. When the volume of the photoelectric conversion unit 6 is made larger, the sensitivity is further improved. Therefore, the first subpixel SP1 has a higher sensitivity than the second subpixel SP2.

As shown in FIG. 1A, the size of each pixel P is the same, but each pixel P has a first subpixel SP1 having a higher sensitivity than the second subpixel SP2 in addition to the second subpixel SP2. By providing the first subpixel SP1 and the second subpixel SP2 having different sensitivities, the dynamic range of each pixel P can be widened.

The first subpixel SP1 and the second subpixel SP2 in the pixel P may contain different materials. The material constituting each subpixel may contain, for example, InGaAs or CuInGaSe ₂ .

FIG. 2 is a block diagram showing a schematic configuration of the solid-state image sensor 1 according to the present embodiment. As shown in FIG. 2, the solid-state image sensor 1 according to the present embodiment includes a pixel array unit 21, a vertical drive circuit 22, a column signal processing circuit 23, a horizontal drive circuit 24, an output circuit 25, and a drive control circuit. It has 26 and.

The pixel array unit 21 has a plurality of pixels P arranged in the horizontal direction and the vertical direction. A row selection line L1 is arranged for each pixel row composed of a plurality of pixels P arranged in the horizontal direction. The plurality of row selection lines L1 extending in the horizontal direction are driven by the vertical drive circuit 22. A signal line L2 is arranged for each pixel row composed of a plurality of pixels P arranged in the vertical direction. A plurality of signal lines L2 extending in the vertical direction are connected to the column signal processing circuit 23. The column signal processing circuit 23 performs signal processing such as removal of noise components included in the signal voltage read from each pixel P via the signal line L2 and adjustment of the signal amplitude. The output signal of the column signal processing circuit 23 is output via the output circuit 25. The column signal processing circuit 23 may perform processing for converting the signal voltage of each signal line L2 into a digital signal.

The drive control circuit 26 generates a clock signal and a control signal that serve as a reference for the operation of the vertical drive circuit 22, the column signal processing circuit 23, and the horizontal drive circuit 24, based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock. The generated clock signal and control signal are input to the vertical drive circuit 22, the column signal processing circuit 23, and the horizontal drive circuit 24.

Each pixel P in the pixel array unit 21 according to the present embodiment has a plurality of subpixels (first subpixel SP1 and second subpixel SP2) as described above. The electrical signals photoelectrically converted by each of the first subpixel SP1 and the second subpixel SP2 in the same pixel P are input to the column signal processing circuit 23 via the same signal line L2 at the same timing. Alternatively, the electrical signals photoelectrically converted by the first subpixel SP1 and the second subpixel SP2 may be input to the column signal processing circuit 23 via the same signal line L2 at different times. Since the first subpixel SP1 and the second subpixel SP2 have different sensitivities, the electric signal photoelectrically converted by the first subpixel SP1 and the electrical signal photoelectrically converted by the second subpixel SP2 are combined. The dynamic range of photoelectric conversion can be further expanded.

In the layout of FIG. 1B, the first subpixel SP1 and the second subpixel SP2 in each pixel P are both rectangular, and the directions of the first subpixel SP1 and the second subpixel SP2 are aligned in each pixel P. An example of placement is shown. On the other hand, in FIG. 3, the first subpixel SP1 and the second subpixel SP2 in each pixel P are both rectangular, and the directions of the first subpixel SP1 and the second subpixel SP2 are different from each other. An example of arranging in each pixel P is shown. As shown in FIG. 3, by arranging the first subpixel SP1 and the second subpixel SP2 in different directions in each pixel P, the size of each subpixel arranged in the pixel P is made as large as possible. As such, the orientations of the first subpixel SP1 and the second subpixel SP2 can be adjusted and arranged. As a result, the size ratio of the first sub-pixel SP1 and the second sub-pixel SP2 can be further increased, and the dynamic range can be further expanded. In FIG. 3, the orientation of the first subpixel SP1 and the orientation of the second subpixel SP2 are offset by 45 degrees from each other, but the degree of offset is arbitrary.

More specifically, in the present embodiment, as shown in FIG. 1A, the area of the second semiconductor layer 8 in the first subpixel SP1 viewed in a plan view from the stacking direction is the area of the second semiconductor layer in the second subpixel SP2. 8 is made larger than the area viewed in a plan view from the stacking direction. Since the first subpixel SP1 has a larger volume of the photoelectric conversion unit 6 than the second subpixel SP2, the area of the second semiconductor layer 8 in the first subpixel SP1 is made larger to increase the saturated charge amount. Can be made larger.

Although FIGS. 1A and 3 show an example in which the first subpixel SP1 and the second subpixel SP2 have a rectangular shape, the shapes of the first subpixel SP1 and the second subpixel SP2 are arbitrary. Further, the shape of the first subpixel SP1 may be different from the shape of the second subpixel SP2.

In the above-mentioned example, all the pixels P in the pixel array unit 21 have a plurality of sub-pixels having different sizes, but only a part of the pixel groups in the pixel array unit 21 has a plurality of sub-pixels having different sizes. It may have pixels.

As described above, in the first embodiment, since a plurality of subpixels having different sizes are provided in one pixel P, the sensitivity of each subpixel in one pixel P can be made different, and the solid-state image sensor 1 can be used. The dynamic range of can be expanded.

(Second embodiment)
In the first embodiment, the element separation layer 7 is arranged at the boundary between the pixel P and the sub-pixel, but a trench is formed in the element separation layer 7 and the trench is filled with a light-shielding material to form a light-shielding layer. May be formed and a light-shielding layer may be arranged along the boundary of the pixel P or the boundary of the sub-pixel.

The solid-state image sensor 1 according to the second embodiment has the same planar layout configuration as in FIG. 1A, and has a plurality of sub-pixels in one pixel P.

FIG. 4A is a plan layout view of the solid-state image sensor 1 according to the second embodiment, and FIG. 4B is a cross-sectional view in the diagonal direction of FIG. 4A. As can be seen by comparing FIGS. 4A and 4B with FIGS. 1A and 1B, in the solid-state image pickup device 1 according to the second embodiment, the light-shielding layer 16 is arranged at least a part of the element separation layer 7. The light-shielding layer 16 is provided along the boundary of the pixel P. The light-shielding layer 16 is provided in the trench formed in the element separation layer 7. The material of the light-shielding layer 16 is titanium Ti, tungsten W, molybdenum Mo, manganese Mn, copper Cu, or the like, and may be an alloy of two or more kinds of metals. The material of the light-shielding layer 16 does not necessarily have to be metal, but is a material capable of absorbing or reflecting the light to be photoelectrically converted by the solid-state image sensor 1. The light-shielding layer 16 is also arranged at the boundary position of each of the plurality of sub-pixels in the pixel P. The light-shielding layer 16 is arranged so as to surround each of the plurality of sub-pixels when viewed in a plane along the stacking direction of the second semiconductor layer 8. The areas of the plurality of sub-pixels surrounded by the light-shielding layer 16 in the pixel P in a plan view along the stacking direction are different from each other.

The light-shielding layer 16 shown in FIGS. 4A and 4B can suppress the incident of light from the adjacent pixel P or sub-pixel. This can reduce crosstalk.

In the solid-state image sensor 1 according to the second embodiment, the light-shielding layer 16 serves as the boundary of the pixel P and the boundary of the sub-pixel in the pixel P. A plurality of regions surrounded by the light-shielding layer 16 are provided in one pixel P, and each region constitutes a different sub-pixel. In the example of FIG. 4A, there are two regions surrounded by the light-shielding layer 16 in one pixel P, one region is the first subpixel SP1 and the other region is the second subpixel SP2. .. Also in this embodiment, there is no particular limitation on the number of sub-pixels provided in the pixel P.

As shown in FIG. 4A, the area of the second semiconductor layer 8 in the first subpixel SP1 viewed in a plan view from the stacking direction and the area of the second semiconductor layer 8 in the second subpixel SP2 viewed in a plan view from the stacking direction. Are different from each other. Specifically, in the first subpixel SP1 having a size larger than that of the second subpixel SP2, the area of the second semiconductor layer 8 is made larger. As a result, the saturated charge amount of the first subpixel SP1 can be further increased and the sensitivity can be further improved, so that the dynamic range of the solid-state image sensor 1 can be widened.

As described above, in the second embodiment, the light-shielding layer 16 is arranged along the boundary between the pixel P and the sub-pixels, and the sizes of the plurality of regions surrounded by the light-shielding layer 16 in the pixel P are different. Not only can crosstalk be reduced by the light-shielding layer 16, but a plurality of sub-pixels having different sensitivities can be provided in the pixel P by the light-shielding layer 16, and the dynamic range of the solid-state image sensor 1 can be expanded.

(Third embodiment)
The second embodiment shows an example in which the sizes of the plurality of subpixels in the pixel P are different, and the size of the second semiconductor layer 8 in each subpixel in the pixel P is also different. The size of the second semiconductor layer 8 in each subpixel in P may be the same.

FIG. 5 is a plan layout view of the solid-state image sensor 1 according to the third embodiment. In the solid-state image sensor 1 of FIG. 5, the light-shielding layer 16 is arranged along the boundary of the pixel P and the boundary of the sub-pixel, as in FIGS. 4A and 4B. Further, the sizes of the plurality of sub-pixels in one pixel P are different. FIG. 5 shows an example in which two subpixels (first subpixel SP1 and second subpixel SP2) having different sizes are provided in one pixel P.

As shown in FIG. 4A, the size of the first subpixel SP1 is larger than the size of the second subpixel SP2. Further, in FIG. 4A, the area viewed in a plan view from the stacking direction of the second semiconductor layer 8 in the first subpixel SP1 is abbreviated as the area viewed in a plan view from the stacking direction of the second semiconductor layer 8 in the second subpixel SP2. It is the same. This is a big difference from FIG. 3A.

Even if the second semiconductor layer 8 in the first subpixel SP1 and the second semiconductor layer 8 in the second subpixel SP2 have the same size, the volume of the photoelectric conversion unit 6 in the first subpixel SP1 is the second sub. Since it is larger than the volume of the photoelectric conversion unit 6 in the pixel SP2, the sensitivity of the first subpixel SP1 can be made higher than that of the second subpixel SP2. Therefore, the dynamic range of the solid-state image sensor 1 according to the third embodiment can be expanded.

As described above, in the second embodiment, the size of the second semiconductor layer 8 is changed according to the size of the subpixel in the pixel P, whereas in the third embodiment, the subpixel in the pixel P is changed. The size of the second semiconductor layer 8 in each subpixel is substantially the same regardless of the size of. As a result, the manufacturing process can be simplified as compared with the solid-state image pickup device 1 according to the second embodiment.

(Fourth Embodiment)
The signal imaged by each pixel P in the solid-state image sensor 1 according to the first to third embodiments described above is sent to the signal line L2 via the readout circuit. At least a part of the readout circuit is formed on, for example, the drive substrate 13 of FIG. 1B.

FIG. 6 is a circuit diagram showing an example of a readout circuit, and FIGS. 7A to 7E are an operation timing diagram and a potential diagram of the readout circuit of FIG.

The readout circuit of FIG. 6 has a current source CS1 and capacitors C1 that equivalently represent the photoelectric conversion operation of the photoelectric conversion unit 6, transistors Q1 to Q5, capacitors C2 and C3, and a current source CS2. Capacitors C1 and C2 are connected in series between the reference voltage Vtop and the ground potential. The transistor Q1 is turned on when the OFG signal input to the gate is at a high level, and the potential of the connection node of the capacitors C1 and C2 is set to the reset voltage VDC. The transistor Q2 is turned on when the TRG signal input to the gate is at a high level, and the charge photoelectrically converted by the photoelectric conversion unit 6 is transferred to the capacitor C3. One end of the capacitor C3 is a floating diffusion FD. More specifically, when the transistor Q2 is turned on, the potentials of the connection node of the capacitors C1 and C2 and the floating diffusion FD which is one end of the capacitor C3 become equal. The transistor Q3 is turned on when the RST signal input to the gate is at a high level to set the floating diffusion FD to the reset voltage VDC. A floating diffusion FD is connected to the gate of the transistor Q4. The transistors Q4 and Q5 are cascode-connected between the power supply voltage VDD and one end of the current source CS2. An SEL signal is input to the gate of the transistor Q5.

During the global operation period, the TRG signal is set to a low level and the transistor Q2 is turned off, the OFG signal is set to a high level and the transistor Q1 is turned on to initialize the charge of the capacitor C2 and set the RST signal to high. The floating diffusion FD is initialized by turning on the transistor Q3 at the level. After that, the TRG signal is temporarily raised to a high level, and the charge signal by photoelectric conversion is transferred to the floating diffusion FD.

During the rolling operation period, after reading the charge signal obtained by photoelectric conversion of the selected pixel P via the transistors Q4 and Q5, the RST signal is temporarily set to a high level and the transistor Q3 is temporarily turned on to set the reset level. The signal is read out via the transistors Q4 and Q5.

More specifically, the readout circuit of FIG. 6 performs a rolling operation after performing a global operation operation as shown in the operation timing diagrams of FIGS. 7A to 7E. During the global operation period, all the pixels P in the pixel array unit 21 operate at the same time. As shown in FIG. 7A, at time t1, since the OFG signal is at a high level, the transistor Q1 is turned on, and the connection node of the capacitors C1 and C2 is set to the reset voltage VDG. At this time, the bottoms of the potential wells on the drain side and the source side of the transistor Q1 in which the OFG signal is input to the gate and the potential wells of the floating diffusion FD become high.

Next, as shown in FIG. 7B, at time t2, the OFG signal becomes low level, so that the transistor Q1 is turned off and the bottom of the potential well of the connection node between the transistor Q1 and the transistor Q2 becomes low.

Next, as shown in FIG. 7C, at time t3, the RST signal becomes low level, so that the transistor Q3 is turned off and the bottom of the potential well of the floating diffusion FD becomes low. Further, the amount of electrons accumulated in the potential well of the connection node between the transistor Q1 and the transistor Q2 decreases according to the amount of charge converted by photoelectric conversion. This decrease in the amount of electrons corresponds to the imaging signal.

Next, as shown in FIG. 7D, at times t4 to t5, the TRG signal once becomes a high level and then changes to a low level, and the transistor Q2 is once turned on and then turned off. As a result, electrons are averaged between the potential well of the connection node between the transistor Q1 and the transistor Q2 and the potential well of the floating diffusion FD. Therefore, gain loss occurs.

Next, as shown in FIG. 7E, at times t6 to t7, the RST signal once becomes a high level and then changes to a low level, and the transistor Q3 is once turned on and then turned off. As a result, the bottom of the well of the potential of the floating diffusion FD is once raised and reset, and then lowered.

The solid-state image sensor 1 according to the first to third embodiments described above includes a plurality of sub-pixels having different sizes in one pixel P. The signal charges photoelectrically converted by the photoelectric conversion unit 6 of these subpixels are synthesized by, for example, a floating diffusion FD, and are supplied to the corresponding signal line L2 via the transistors Q4 and Q5.

<< Application example >>
The technique according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure is any kind of movement such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, a robot, a construction machine, and an agricultural machine (tractor). It may be realized as a device mounted on the body.

FIG. 8 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile control system to which the technique according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in FIG. 8, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside information detection unit 7400, an in-vehicle information detection unit 7500, and an integrated control unit 7600. .. The communication network 7010 connecting these multiple control units conforms to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network) or FlexRay (registered trademark). It may be an in-vehicle communication network.

Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores programs executed by the microcomputer or parameters used for various arithmetic, and a drive circuit that drives various controlled devices. To prepare for. Each control unit is provided with a network I / F for communicating with other control units via the communication network 7010, and is connected to devices or sensors inside and outside the vehicle by wired communication or wireless communication. A communication I / F for performing communication is provided. In FIG. 8, as the functional configuration of the integrated control unit 7600, the microcomputer 7610, the general-purpose communication I / F7620, the dedicated communication I / F7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F7660, the audio image output unit 7670, The vehicle-mounted network I / F 7680 and the storage unit 7690 are illustrated. Other control units also include a microcomputer, a communication I / F, a storage unit, and the like.

The drive system control unit 7100 controls the operation of the device related to the drive system of the vehicle according to various programs. For example, the drive system control unit 7100 has a driving force generator for generating the driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism for adjusting and a braking device for generating braking force of the vehicle. The drive system control unit 7100 may have a function as a control device such as ABS (Antilock Brake System) or ESC (Electronic Stability Control).

The vehicle state detection unit 7110 is connected to the drive system control unit 7100. The vehicle state detection unit 7110 may include, for example, a gyro sensor that detects the angular speed of the axial rotation motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, an accelerator pedal operation amount, a brake pedal operation amount, or steering wheel steering. It includes at least one of sensors for detecting angles, engine speeds, wheel speeds, and the like. The drive system control unit 7100 performs arithmetic processing using a signal input from the vehicle state detection unit 7110, and controls an internal combustion engine, a drive motor, an electric power steering device, a brake device, and the like.

The body system control unit 7200 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 7200 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, turn signals or fog lamps. In this case, a radio wave transmitted from a portable device that substitutes for a key or signals of various switches may be input to the body system control unit 7200. The body system control unit 7200 receives inputs of these radio waves or signals and controls a vehicle door lock device, a power window device, a lamp, and the like.

The battery control unit 7300 controls the secondary battery 7310, which is the power supply source of the drive motor, according to various programs. For example, information such as the battery temperature, the battery output voltage, or the remaining capacity of the battery is input to the battery control unit 7300 from the battery device including the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals, and controls the temperature control of the secondary battery 7310 or the cooling device provided in the battery device.

The outside information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of the image pickup unit 7410 and the vehicle exterior information detection unit 7420 is connected to the vehicle exterior information detection unit 7400. The image pickup unit 7410 includes at least one of a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The vehicle outside information detection unit 7420 is used, for example, to detect the current weather or an environment sensor for detecting the weather, or other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000. At least one of the ambient information detection sensors is included.

The environment sensor may be, for example, at least one of a raindrop sensor that detects rainy weather, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The ambient information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The image pickup unit 7410 and the vehicle exterior information detection unit 7420 may be provided as independent sensors or devices, or may be provided as a device in which a plurality of sensors or devices are integrated.

Here, FIG. 9 shows an example of the installation position of the image pickup unit 7410 and the vehicle exterior information detection unit 7420. The image pickup unit 7910, 7912, 7914, 7916, 7918 are provided, for example, at at least one of the front nose, side mirror, rear bumper, back door, and upper part of the windshield of the vehicle interior of the vehicle 7900. The image pickup unit 7910 provided in the front nose and the image pickup section 7918 provided in the upper part of the windshield in the vehicle interior mainly acquire an image in front of the vehicle 7900. The image pickup units 7912 and 7914 provided in the side mirrors mainly acquire images of the side of the vehicle 7900. The image pickup unit 7916 provided in the rear bumper or the back door mainly acquires an image of the rear of the vehicle 7900. The image pickup unit 7918 provided on the upper part of the windshield in the vehicle interior is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

Note that FIG. 9 shows an example of the shooting range of each of the imaging units 7910, 7912, 7914, 7916. The imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, the imaging ranges b and c indicate the imaging range of the imaging units 7912 and 7914 provided on the side mirrors, respectively, and the imaging range d indicates the imaging range d. The imaging range of the imaging unit 7916 provided on the rear bumper or the back door is shown. For example, by superimposing the image data captured by the image pickup units 7910, 7912, 7914, 7916, a bird's-eye view image of the vehicle 7900 can be obtained.

The vehicle exterior information detection unit 7920, 7922, 7924, 7926, 7928, 7930 provided on the front, rear, side, corner and the upper part of the windshield in the vehicle interior of the vehicle 7900 may be, for example, an ultrasonic sensor or a radar device. The vehicle exterior information detection units 7920, 7926, 7930 provided on the front nose, rear bumper, back door, and upper part of the windshield in the vehicle interior of the vehicle 7900 may be, for example, a lidar device. These out-of-vehicle information detection units 7920 to 7930 are mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, or the like.

Return to Fig. 8 and continue the explanation. The vehicle outside information detection unit 7400 causes the image pickup unit 7410 to capture an image of the outside of the vehicle and receives the captured image data. Further, the vehicle outside information detection unit 7400 receives the detection information from the connected vehicle outside information detection unit 7420. When the vehicle exterior information detection unit 7420 is an ultrasonic sensor, a radar device, or a lidar device, the vehicle exterior information detection unit 7400 transmits ultrasonic waves, electromagnetic waves, or the like, and receives received reflected wave information. The out-of-vehicle information detection unit 7400 may perform object detection processing or distance detection processing such as a person, a vehicle, an obstacle, a sign, or a character on a road surface based on the received information. The out-of-vehicle information detection unit 7400 may perform an environment recognition process for recognizing rainfall, fog, road surface conditions, etc. based on the received information. The out-of-vehicle information detection unit 7400 may calculate the distance to an object outside the vehicle based on the received information.

Further, the vehicle outside information detection unit 7400 may perform image recognition processing or distance detection processing for recognizing a person, a vehicle, an obstacle, a sign, a character on the road surface, or the like based on the received image data. The vehicle exterior information detection unit 7400 performs processing such as distortion correction or alignment on the received image data, and synthesizes image data captured by different image pickup units 7410 to generate a bird's-eye view image or a panoramic image. May be good. The vehicle exterior information detection unit 7400 may perform a viewpoint conversion process using image data captured by different image pickup units 7410.

The in-vehicle information detection unit 7500 detects the in-vehicle information. For example, a driver state detection unit 7510 that detects the state of the driver is connected to the in-vehicle information detection unit 7500. The driver state detection unit 7510 may include a camera that captures the driver, a biosensor that detects the driver's biological information, a microphone that collects sound in the vehicle interior, and the like. The biosensor is provided on, for example, a seat surface or a steering wheel, and detects biometric information of a passenger sitting on the seat or a driver holding the steering wheel. The in-vehicle information detection unit 7500 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 7510, and determines whether or not the driver is dozing. You may. The in-vehicle information detection unit 7500 may perform processing such as noise canceling processing on the collected audio signal.

The integrated control unit 7600 controls the overall operation in the vehicle control system 7000 according to various programs. An input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is realized by a device that can be input-operated by the passenger, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by recognizing the voice input by the microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared rays or other radio waves, or an external connection device such as a mobile phone or a PDA (Personal Digital Assistant) corresponding to the operation of the vehicle control system 7000. You may. The input unit 7800 may be, for example, a camera, in which case the passenger can input information by gesture. Alternatively, data obtained by detecting the movement of the wearable device worn by the passenger may be input. Further, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on the information input by the passenger or the like using the above input unit 7800 and outputs the input signal to the integrated control unit 7600. By operating the input unit 7800, the passenger or the like inputs various data to the vehicle control system 7000 and instructs the processing operation.

The storage unit 7690 may include a ROM (Read Only Memory) for storing various programs executed by the microcomputer, and a RAM (Random Access Memory) for storing various parameters, calculation results, sensor values, and the like. Further, the storage unit 7690 may be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, an optical magnetic storage device, or the like.

The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication with various devices existing in the external environment 7750. General-purpose communication I / F7620 is a cellular communication protocol such as GSM (registered trademark) (Global System of Mobile communications), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution) or LTE-A (LTE-Advanced). , Or other wireless communication protocols such as wireless LAN (also referred to as Wi-Fi®), Bluetooth® may be implemented. The general-purpose communication I / F7620 connects to a device (for example, an application server or a control server) existing on an external network (for example, the Internet, a cloud network, or a business-specific network) via a base station or an access point, for example. You may. Further, the general-purpose communication I / F7620 uses, for example, P2P (Peer To Peer) technology, and is a terminal existing in the vicinity of the vehicle (for example, a driver, a pedestrian or a store terminal, or an MTC (Machine Type Communication) terminal). May be connected with.

The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol formulated for use in a vehicle. The dedicated communication I / F7630 uses a standard protocol such as WAVE (Wireless Access in Vehicle Environment), DSRC (Dedicated Short Range Communications), which is a combination of the lower layer IEEE802.11p and the upper layer IEEE1609, or a cellular communication protocol. May be implemented. Dedicated communication I / F7630 is typically vehicle-to-vehicle (Vehicle to Vehicle) communication, road-to-vehicle (Vehicle to Infrastructure) communication, vehicle-to-house (Vehicle to Home) communication, and pedestrian-to-vehicle (Vehicle to Pedestrian) communication. ) Carry out V2X communication, a concept that includes one or more of the communications.

The positioning unit 7640 receives, for example, a GNSS signal from a GNSS (Global Navigation Satellite System) satellite (for example, a GPS signal from a GPS (Global Positioning System) satellite), executes positioning, and executes positioning, and the latitude, longitude, and altitude of the vehicle. Generate location information including. The positioning unit 7640 may specify the current position by exchanging signals with the wireless access point, or may acquire position information from a terminal such as a mobile phone, PHS, or smartphone having a positioning function.

The beacon receiving unit 7650 receives, for example, a radio wave or an electromagnetic wave transmitted from a radio station or the like installed on a road, and acquires information such as a current position, a traffic jam, a road closure, or a required time. The function of the beacon receiving unit 7650 may be included in the above-mentioned dedicated communication I / F 7630.

The in-vehicle device I / F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and various in-vehicle devices 7760 existing in the vehicle. The in-vehicle device I / F7660 may establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication) or WUSB (Wireless USB). In addition, the in-vehicle device I / F7660 is via a connection terminal (and a cable if necessary) (not shown), USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface, or MHL (Mobile High)). -Definition Link) and other wired connections may be established. The in-vehicle device 7760 includes, for example, at least one of a passenger's mobile device or wearable device, or an information device carried in or attached to the vehicle. Further, the in-vehicle device 7760 may include a navigation device for searching a route to an arbitrary destination. The in-vehicle device I / F 7660 may be a control signal to and from these in-vehicle devices 7760. Or exchange the data signal.

The in-vehicle network I / F7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The vehicle-mounted network I / F7680 transmits / receives signals and the like according to a predetermined protocol supported by the communication network 7010.

The microcomputer 7610 of the integrated control unit 7600 is via at least one of general-purpose communication I / F7620, dedicated communication I / F7630, positioning unit 7640, beacon receiving unit 7650, in-vehicle device I / F7660, and in-vehicle network I / F7680. Based on the information acquired in the above, the vehicle control system 7000 is controlled according to various programs. For example, the microcomputer 7610 calculates the control target value of the driving force generator, the steering mechanism, or the braking device based on the acquired information inside and outside the vehicle, and outputs a control command to the drive system control unit 7100. May be good. For example, the microcomputer 7610 realizes ADAS (Advanced Driver Assistance System) functions including vehicle collision avoidance or impact mitigation, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane deviation warning, and the like. Cooperative control may be performed for the purpose of. In addition, the microcomputer 7610 automatically travels autonomously without relying on the driver's operation by controlling the driving force generator, steering mechanism, braking device, etc. based on the acquired information on the surroundings of the vehicle. Coordinated control may be performed for the purpose of driving or the like.

The microcomputer 7610 has information acquired via at least one of general-purpose communication I / F 7620, dedicated communication I / F 7630, positioning unit 7640, beacon receiving unit 7650, in-vehicle device I / F 7660, and in-vehicle network I / F 7680. Based on the above, three-dimensional distance information between the vehicle and an object such as a surrounding structure or a person may be generated, and local map information including the peripheral information of the current position of the vehicle may be created. Further, the microcomputer 7610 may predict the danger of a vehicle collision, a pedestrian or the like approaching or entering a closed road, and generate a warning signal based on the acquired information. The warning signal may be, for example, a signal for generating a warning sound or lighting a warning lamp.

The audio image output unit 7670 transmits an output signal of at least one of audio and image to an output device capable of visually or audibly notifying information to the passenger or the outside of the vehicle. In the example of FIG. 8, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are exemplified as output devices. The display unit 7720 may include, for example, at least one of an onboard display and a head-up display. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may be other devices such as headphones, wearable devices such as eyeglass-type displays worn by passengers, projectors or lamps other than these devices. When the output device is a display device, the display device displays the results obtained by various processes performed by the microcomputer 7610 or the information received from other control units in various formats such as texts, images, tables, and graphs. Display visually. When the output device is an audio output device, the audio output device converts an audio signal composed of reproduced audio data, acoustic data, or the like into an analog signal and outputs the audio signal audibly.

In the example shown in FIG. 8, at least two control units connected via the communication network 7010 may be integrated as one control unit. Alternatively, each control unit may be composed of a plurality of control units. Further, the vehicle control system 7000 may include another control unit (not shown). Further, in the above description, the other control unit may have a part or all of the functions carried out by any of the control units. That is, as long as information is transmitted and received via the communication network 7010, predetermined arithmetic processing may be performed by any of the control units. Similarly, a sensor or device connected to any control unit may be connected to another control unit, and a plurality of control units may send and receive detection information to and from each other via the communication network 7010. ..
The present technology can have the following configurations.

The present technology can have the following configurations.
(1) A first semiconductor layer having a first conductive type first compound semiconductor material, and
The photoelectric conversion layer arranged on the first semiconductor layer and
A second conductive type second semiconductor layer partially arranged on the photoelectric conversion layer and arranged so as to be in contact with the photoelectric conversion layer.
The first semiconductor layer, the photoelectric conversion layer, and the element separation layer for separating the second semiconductor layer on a pixel-by-pixel basis are provided.
The pixel is a solid-state image sensor having a plurality of sub-pixels having different sensitivities and sizes.
(2) The second semiconductor layer has a plurality of well regions separated from each other corresponding to each of the plurality of subpixels.
The solid-state image pickup device according to (1), wherein the plurality of well regions have different sizes.
(3) The solid-state image sensor according to (2), wherein the plurality of well regions have different areas when viewed in a plan view along the stacking direction of the second semiconductor layer.
(4) The solid-state image pickup device according to (3), wherein the plurality of well regions have different planar sizes.
(5) The solid-state image sensor according to (4), wherein the plurality of well regions are arranged in the corresponding pixels so as to be oriented in the same direction.
(6) The solid-state image sensor according to (4), wherein the plurality of well regions are arranged in different directions in the corresponding pixels.
(7) The solid-state image pickup apparatus according to any one of (1) to (6), comprising a light-shielding layer arranged in at least a part of the element separation layer.
(8) The solid-state image pickup device according to (7), wherein the light-shielding layer is arranged at a boundary position of the pixels.
(9) The solid-state image pickup device according to (7), wherein the light-shielding layer is arranged at the boundary position of each of the plurality of sub-pixels in the pixel.
(10) Any of (7) to (9), wherein the light-shielding layer is arranged so as to surround each of the plurality of subpixels when viewed in a plan view along the stacking direction of the second semiconductor layer. The solid-state image sensor according to one item.
(11) The solid-state image pickup device according to (10), wherein the plurality of sub-pixels surrounded by the light-shielding layer in the pixel have different areas in a plan view along the stacking direction.
(12) A light-shielding layer arranged at the boundary position of each of the plurality of sub-pixels in the pixel is provided.
The solid-state image pickup device according to any one of (2) to (6), wherein the plurality of well regions are regions separated by the light-shielding layer.
(13) The areas of the plurality of sub-pixels divided by the light-shielding layer in the pixels in a plan view along the stacking direction are different from each other.
The solid-state image pickup apparatus according to (12), wherein the areas of the plurality of well regions in the pixel viewed in a plan view along the stacking direction are all the same.
(14) The solid-state image sensor according to any one of (1) to (13), wherein the photoelectric conversion layer of the plurality of subpixels in the pixel contains a different material for each subpixel.
(15) The solid-state image sensor according to (14), wherein the material comprises InGaAs or CuInGaSe ₂ .
(16) A third semiconductor layer arranged on the photoelectric conversion layer and having the first conductive type second compound semiconductor material is provided.
The solid-state image pickup device according to any one of (1) to (15), wherein the second semiconductor layer is arranged on the third semiconductor layer.

The aspects of the present disclosure are not limited to the individual embodiments described above, but also include various modifications that can be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-mentioned contents. That is, various additions, changes and partial deletions are possible without departing from the conceptual idea and purpose of the present disclosure derived from the contents specified in the claims and their equivalents.

1 solid-state imager, 2 base substrate, 3 1st semiconductor layer, 4 photoelectric conversion layer, 5 3rd semiconductor layer, 6 photoelectric conversion unit, 7 element separation layer, 8 2nd semiconductor layer, 9 1st electrode layer, 10th 2 electrode layer, 11 coating layer, 12 bonding member, 13 drive substrate, 14 flattening layer, 15 microlens, 16 light-shielding layer, 21 pixel array section, 22 vertical drive circuit, 23 column signal processing circuit, 24 horizontal drive circuit , 25 output circuit, 26 drive control circuit,

Claims (16)

A first semiconductor layer having a first conductive type first compound semiconductor material,
The photoelectric conversion layer arranged on the first semiconductor layer and
A second conductive type second semiconductor layer partially arranged on the photoelectric conversion layer and arranged so as to be in contact with the photoelectric conversion layer.
The first semiconductor layer, the photoelectric conversion layer, and the element separation layer for separating the second semiconductor layer on a pixel-by-pixel basis are provided.
The pixel is a solid-state image sensor having a plurality of sub-pixels having different sensitivities and sizes. The second semiconductor layer has a plurality of well regions separated from each other corresponding to each of the plurality of subpixels.
The solid-state image pickup device according to claim 1, wherein the plurality of well regions have different sizes. The solid-state image pickup device according to claim 2, wherein the plurality of well regions have different areas when viewed in a plan view along the stacking direction of the second semiconductor layer. The solid-state image pickup device according to claim 3, wherein the plurality of well regions have different planar sizes. The solid-state image pickup device according to claim 4, wherein the plurality of well regions are arranged in the corresponding pixels so as to be oriented in the same direction. The solid-state image pickup device according to claim 4, wherein the plurality of well regions are arranged in different directions in the corresponding pixels. The solid-state image pickup apparatus according to claim 1, further comprising a light-shielding layer arranged in at least a part of the element separation layer. The solid-state image pickup device according to claim 7, wherein the light-shielding layer is arranged at a boundary position of the pixels. The solid-state image pickup device according to claim 7, wherein the light-shielding layer is arranged at a boundary position of each of the plurality of sub-pixels in the pixel. The solid-state image pickup device according to claim 7, wherein the light-shielding layer is arranged so as to surround each of the plurality of subpixels when viewed in a plan view along the stacking direction of the second semiconductor layer. The solid-state image pickup device according to claim 10, wherein the plurality of sub-pixels surrounded by the light-shielding layer in the pixel have different areas in a plan view along the stacking direction. A light-shielding layer arranged at the boundary position of each of the plurality of sub-pixels in the pixel is provided.
The solid-state image pickup device according to claim 2, wherein the plurality of well regions are regions separated by the light-shielding layer. The areas of the plurality of sub-pixels divided by the light-shielding layer in the pixels in a plan view along the stacking direction are different from each other.
The solid-state image pickup device according to claim 12, wherein the areas of the plurality of well regions in the pixel viewed in a plan view along the stacking direction are all the same. The solid-state image pickup device according to claim 1, wherein the photoelectric conversion layer of the plurality of subpixels in the pixel contains a different material for each subpixel. The solid-state image sensor according to claim 14, wherein the material comprises InGaAs or CuInGaSe ₂ . A third semiconductor layer arranged on the photoelectric conversion layer and having the first conductive type second compound semiconductor material is provided.
The solid-state image sensor according to claim 1, wherein the second semiconductor layer is arranged on the third semiconductor layer.

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