Light receiving element, solid-state imaging device, and distance measuring device

Abstract

The object of the present invention is to improve the ranging accuracy. A light receiving element according to an embodiment of the present invention includes: a semiconductor substrate (40); and a lattice-shaped pixel separation portion (46) which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix. Each of the pixel regions includes: a first semiconductor region (30A) which is arranged on the first surface side in the semiconductor substrate; a second semiconductor region (30B) which is arranged on the first surface side in the semiconductor substrate to be separated from the first semiconductor region; and a first blocking region (501) which is arranged between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate.

Description

Technical Field

[0001] The present disclosure relates to a light receiving element, a solid-state imaging device, and a distance measuring device. Background Art

[0002] Conventionally, a distance measuring sensor using an indirect ToF (Time of Flight) method is known, in which the distance to an object is measured based on a signal charge obtained by emitting light from a light source having a specific phase and receiving its reflected light.

[0003] In such a distance measurement sensor using an indirect ToF method (hereinafter referred to as an indirect ToF sensor), a sensor capable of quickly distributing the signal charge of reflected light to different areas is essential. Therefore, the following patent document 1 discloses a technology that quickly modulates a wide range of areas in a substrate of a sensor by, for example, directly applying a voltage to the substrate of the sensor to generate a current in the substrate. This sensor is also called a current assisted photonic demodulator (CAPD: current assisted photonic demodulator) type indirect ToF sensor.

[0004] [Citation List]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-86904 Summary of the invention

[0007] [Technical issues]

[0008] However, the CAPD type indirect ToF sensor according to the conventional art has a problem in that pixels are not sufficiently separated, and thus light reflected in a specific pixel leaks into an adjacent pixel and causes color mixing, resulting in a decrease in distance measurement accuracy.

[0009] Therefore, the present disclosure proposes a light receiving element, a solid-state imaging device, and a distance measuring device capable of improving distance measuring accuracy.

[0010] [Solution to the problem]

[0011] In order to solve the above-mentioned problems, according to one aspect of the present disclosure, a light receiving element includes: a semiconductor substrate; and a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form, wherein each of the pixel regions includes: a first semiconductor region, which is arranged on a first surface side in the semiconductor substrate; a second semiconductor region, which is arranged on the first surface side in the semiconductor substrate separately from the first semiconductor region; and a first blocking region, which is arranged between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 : is a block diagram showing a schematic configuration example of a ToF sensor as a distance measuring device according to the first embodiment.

[0013] Figure 2 is a block diagram showing a schematic configuration example of a solid-state imaging device as a light receiving unit according to the first embodiment.

[0014] Figure 3 is a circuit diagram showing an example of an equivalent circuit of a unit pixel according to the first embodiment.

[0015] Figure 4 is a diagram showing a chip configuration example of the solid-state imaging device according to the first embodiment.

[0016] Figure 5 is a plan view showing a layout example of the light receiving element according to the first embodiment.

[0017] Figure 6 It is shown Figure 5 A plan view showing an example of the dimensions of a light receiving element.

[0018] Figure 7 is a plan view showing a positional relationship between a light receiving element and a light shielding film when the semiconductor substrate according to the first embodiment is viewed in a direction perpendicular to a light incident surface.

[0019] Figure 8 It is a diagram for explaining the progress of light incident on a light receiving element that does not include a pixel separation portion.

[0020] Fig. 9 is a cross-sectional view showing a schematic configuration example of a light receiving element according to the first embodiment.

[0021] Fig.10 is shown when viewed in a direction perpendicular to the light incident surface Fig. 9 A top view showing the positional relationship between the light receiving element and the pixel separation portion on a semiconductor substrate shown.

[0022] Fig.11 is a cross-sectional view showing a schematic configuration example of a light receiving element according to a first modification example of the first embodiment.

[0023] Fig.12 is a cross-sectional view showing a schematic configuration example of a light receiving element according to a second modification example of the first embodiment.

[0024] Fig.13 is a plan view showing an example of the layout of a light receiving element according to the second embodiment.

[0025] Fig.14 It is shown Fig.13 A plan view showing an example of the dimensions of a light receiving element.

[0026] Fig.15 is a diagram showing a planar layout example of a pixel separation section according to a first example of the second embodiment.

[0027] Fig.16 It is shown Fig.15 A cross-sectional view of an example of a cross-sectional structure in plane BB.

[0028] Fig.17 It is shown Fig.15 A cross-sectional view of an example of a cross-sectional structure in plane CC.

[0029] Fig.18 is a diagram showing a planar layout example of a pixel separation section according to a second example of the second embodiment.

[0030] Fig.19 It is shown Fig.18 A cross-sectional view of an example of a cross-sectional structure in plane DD.

[0031] Fig. 20 is a diagram showing a planar layout example of a pixel separation section according to a third example of the second embodiment.

[0032] Fig.21 is a plan view showing a layout example of a light receiving element according to the third embodiment.

[0033] Fig. 22 It is shown Fig.21 A plan view showing an example of the dimensions of a light receiving element.

[0034] Fig.23 is a diagram showing a planar layout example of a pixel separation section according to a first example of the third embodiment.

[0035] Fig.24 It is shown Fig.23A cross-sectional view of an example of a cross-sectional structure in plane EE.

[0036] Fig.25 is a diagram showing a planar layout example of a pixel separation section according to a second example of the third embodiment.

[0037] Fig.26 is a plan view showing a layout example of a light receiving element according to a fourth embodiment.

[0038] Fig. 27 is a diagram showing an example of a planar layout of a pixel separation section according to the fourth embodiment.

[0039] Fig.28 is a diagram showing another example of the planar layout of the pixel separation section according to the fourth embodiment.

[0040] Fig.29 A diagram for explaining the movement of electric charges generated in a light receiving element.

[0041] Fig.30 is a plan view showing an example of the layout of a light receiving element according to the fifth embodiment.

[0042] Fig.31 It is shown Fig.30 Cross-sectional view of an example of a cross-sectional structure in plane FF.

[0043] Fig.32 is a plan view showing a configuration example of a barrier region according to a first modification example of the fifth embodiment.

[0044] Fig.33 : is a plan view showing a configuration example of a barrier region according to a second modification example of the fifth embodiment.

[0045] Fig.34 is a cross-sectional view showing a configuration example of a barrier region according to a third modification example of the fifth embodiment.

[0046] Fig.35 is a cross-sectional view showing a configuration example of a barrier region according to a fourth modification example of the fifth embodiment.

[0047] Fig.36 is a cross-sectional view showing a configuration example of a barrier region according to a fifth modification example of the fifth embodiment.

[0048] Fig.37 is a plan view showing a configuration example of a barrier region according to a first example of the sixth embodiment.

[0049] Fig.38 is a plan view showing a configuration example of a barrier region according to a second example of the sixth embodiment.

[0050] Fig.39 is a plan view showing a configuration example of a barrier region according to a third example of the sixth embodiment.

[0051] Fig.40 is a plan view showing a configuration example of a barrier region according to a fourth example of the sixth embodiment.

[0052] Fig.41 is a sectional view showing a schematic configuration example of a light receiving element according to a seventh embodiment.

[0053] Fig.42 It is a block diagram showing a schematic configuration example of a vehicle control system.

[0054] Fig.43 2 is an explanatory diagram showing an example of installation positions of the vehicle exterior information detection unit and the imaging unit. DETAILED DESCRIPTION

[0055] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same parts in the following embodiments are denoted by the same reference numerals and repeated descriptions are omitted.

[0056] In addition, the present disclosure will be described in the order of the following items.

[0057] 1. First Implementation Method

[0058] 1.1 Distance measuring device (ToF sensor)

[0059] 1.2 Configuration Example of Solid-State Imaging Device

[0060] 1.3 Example of circuit configuration of unit pixel

[0061] 1.4 Example of unit pixel readout operation

[0062] 1.5 Example of chip configuration

[0063] 1.6 Example of Planar Layout of Light Receiving Element

[0064] 1.7 Optical separation between light receiving elements

[0065] 1.8 Example of cross-sectional structure of unit pixel

[0066] 1.9 Function and Effect

[0067] 1.10 Modification of Pixel Separation Unit

[0068] 1.10.1 First Modification

[0069] 1.10.2 Second Modification

[0070] 2. Second Implementation Method

[0071] 2.1 Example of planar layout of light receiving element

[0072] 2.2 Example of Planar Layout of Pixel Separation Unit

[0073] 2.2.1 First Example

[0074] 2.2.2 Second Example

[0075] 2.2.3 Third Example

[0076] 2.3 Function and Effect

[0077] 3. Third Implementation Plan

[0078] 3.1 Example of Planar Layout of Light Receiving Element

[0079] 3.2 Example of Planar Layout of Pixel Separation Unit

[0080] 3.2.1 First Example

[0081] 3.2.2 Second Example

[0082] 3.3 Function and Effect

[0083] 4. Fourth Implementation Method

[0084] 5. Fifth Implementation Method

[0085] 5.1 Example of the structure of a light receiving element

[0086] 5.2 Function and Effect

[0087] 5.3 Variations of the blocking area

[0088] 5.3.1 First Modification

[0089] 5.3.2 Second Modification

[0090] 5.3.3 Third variant

[0091] 5.3.4 Fourth Modification

[0092] 5.3.5 Fifth variant

[0093] 6. Sixth Implementation Method

[0094] 6.1 First Example

[0095] 6.2 Second Example

[0096] 6.3 Third Example

[0097] 6.4 Fourth Example

[0098] 6.5 Function and Effect

[0099] 7. Seventh Implementation Plan

[0100] 8. Application examples

[0101] 1. First Implementation Method

[0102] First, the first embodiment will be described in detail with reference to the accompanying drawings. In addition, in the first embodiment, for example, a light receiving element, a solid-state imaging device, and a distance measuring device that measure the distance to an object using an indirect ToF method will be described.

[0103] For example, the light receiving element, the solid-state imaging device, and the distance measuring device according to the present embodiment can be applied to: an in-vehicle system that is installed in a vehicle and measures the distance to a target object outside the vehicle; and a gesture recognition system that measures the distance to a target object (e.g., a user's hand) and recognizes the user's gesture based on the measurement result, etc. In this case, the gesture recognition result can also be used, for example, for the operation of a car navigation system, etc.

[0104] 1.1 Distance measuring device (ToF sensor)

[0105] Figure 1 1 is a block diagram showing a schematic configuration example of a ToF sensor as a distance measuring device according to the present embodiment. Figure 1 As shown, the ToF sensor 1 includes a control unit 11 , a light emitting unit 13 , a light receiving unit 14 , an arithmetic operation unit 15 , and an external interface (I / F) 19 .

[0106] The control unit 11 includes, for example, an information processing device such as a central processing unit (CPU), and controls each component of the ToF sensor 1 .

[0107] The external I / F 19 may be a communication adapter for establishing communication with the external host 80 via a communication network based on any standard such as a controller area network (CAN), a local interconnect network (LIN), and FlexRay (registered trademark) in addition to a wireless local area network (LAN) and a wired LAN.

[0108] Here, the host 80 may be, for example, an engine control unit (ECU) installed in a car or the like when the ToF sensor 1 is provided in the car or the like. In addition, when the ToF sensor 1 is installed in an autonomous mobile robot such as a household pet robot and an autonomous mobile body such as a robot vacuum cleaner, an unmanned aerial vehicle, or a tracking transport robot, the host 80 may be a control device or the like that controls the above autonomous mobile body.

[0109] The light emitting unit 13 includes, for example, one or more semiconductor laser diodes as a light source, and emits a pulsed laser L1 having a predetermined duration at a predetermined cycle (also referred to as a light emitting cycle). The light emitting unit 13 emits the laser L1 toward an angle range that is at least equal to or greater than the viewing angle of the light receiving unit 14. In addition, the light emitting unit 13 emits the laser L1 having a duration of 10 ns (nanoseconds) at a cycle of 100 MHz (megahertz), for example. For example, when there is an object 90 within the ranging range, the laser L1 emitted from the light emitting unit 13 is reflected by the object 90 and is incident on the light receiving unit 14 as reflected light L2.

[0110] Although the light receiving unit 14 will be described in detail later, the light receiving unit 14 includes, for example, a plurality of pixels arranged in a two-dimensional lattice shape and outputs signal intensity (hereinafter referred to as a pixel signal) detected by each pixel after the light emitting unit 13 emits light.

[0111] The arithmetic operation unit 15 generates a depth image within the viewing angle of the light receiving unit 14 based on the pixel signal output from the light receiving unit 14. Here, the arithmetic operation unit 15 may perform predetermined processing such as noise removal on the generated depth image. The depth image generated by the arithmetic operation unit 15 may be output to the host 80 through the external I / F 19, for example.

[0112] 1.2. Configuration example of solid-state imaging device

[0113] Figure 2 is a block diagram showing a schematic configuration example of a solid-state imaging device as a light receiving unit according to the first embodiment.

[0114] Figure 2 The solid-state imaging device 100 shown is provided in a distance measuring device which is a back-illuminated CAPD indirect ToF sensor (hereinafter simply referred to as a CAPD sensor) and has a distance measuring function.

[0115] The solid-state imaging device 100 includes a pixel array unit 101 and peripheral circuits. The peripheral circuits may include, for example, a vertical drive circuit 103, a column processing circuit 104, a horizontal drive circuit 105, and a system control unit 102.

[0116] The solid-state imaging device 100 may further include a signal processing unit 106 and a data storage unit 107. In addition, the signal processing unit 106 and the data storage unit 107 may be mounted on the same substrate as that of the solid-state imaging device 100, or may be mounted on a substrate different from that of the solid-state imaging device 100 in the distance measuring device.

[0117] The pixel array unit 101 includes a configuration in which pixels (hereinafter referred to as unit pixels) 20 are arranged in the row direction and the column direction (i.e., in a two-dimensional lattice shape), and the pixels 20 generate charges in response to the amount of light received and output signals in response to the charges. That is, the pixel array unit 101 includes a plurality of unit pixels 20 that perform photoelectric conversion on incident light and output signals in response to the charges obtained as a result of the photoelectric conversion.

[0118] Here, the row direction refers to the arrangement direction of the unit pixels 20 in a pixel row (horizontal direction in the figure), and the column direction refers to the arrangement direction of the unit pixels 20 in a pixel column (vertical direction in the figure).

[0119] In the pixel array unit 101, in a matrix-shaped pixel array, a pixel drive line LD is arranged along the row direction for each pixel row, and two vertical signal lines VSL are arranged along the column direction for each pixel column. For example, the pixel drive line LD transmits a drive signal for driving when a signal is read out from the unit pixel 20. In addition, although Figure 2 The pixel drive line LD is shown as one wiring, but is not limited to one wiring. In addition, one end of the pixel drive line LD is connected to the output end of the vertical drive circuit 103 corresponding to each row.

[0120] The vertical driving circuit 103 includes a shift register and an address decoder, etc., and drives each unit pixel 20 of the pixel array unit 101 for all pixels simultaneously or in units of rows, etc. That is, the vertical driving circuit 103 constitutes a driving unit that controls the operation of each unit pixel 20 of the pixel array unit 101 together with the system control unit 102 that controls the vertical driving circuit 103.

[0121] In addition, in the distance measurement using the indirect ToF method, the number of elements (CAPD elements) that are driven quickly and connected to a control line will affect the controllability and driving accuracy of the fast drive. In many cases, the solid-state imaging element used for distance measurement using the indirect ToF method includes a pixel array that is long in the horizontal direction. Therefore, in this case, for the control line of the element that is driven quickly, the vertical signal line VSL and other control lines that are long in the vertical direction can also be used. In this case, for example, a plurality of unit pixels 20 arranged in the vertical direction are connected to the vertical signal line VSL and other control lines that are long in the vertical direction, and through the vertical signal line VSL and other control lines, the unit pixels 20, i.e., the solid-state imaging device 100, are driven by a driving unit and a horizontal driving circuit 105 that are separately arranged from the vertical driving circuit 103.

[0122] Signals output from each unit pixel 20 of a pixel row according to drive control of the vertical drive circuit 103 are input to the column processing circuit 104 through the vertical signal line VSL. The column processing circuit 104 performs predetermined signal processing on the signals output from each unit pixel 20 through the vertical signal line VSL and temporarily holds the pixel signals after the signal processing.

[0123] Specifically, the column processing circuit 104 performs noise removal and analog-to-digital (AD) conversion and the like as signal processing.

[0124] The horizontal driving circuit 105 includes a shift register, an address decoder, etc., and sequentially selects unit circuits corresponding to pixel columns of the column processing circuit 104. Through such selective scanning by the horizontal driving circuit 105, pixel signals processed by the column processing circuit 104 for each unit circuit are sequentially output.

[0125] The system control unit 102 includes a timing generator and the like for generating various timing signals, and performs drive control of the vertical drive circuit 103 , the column processing circuit 104 , the horizontal drive circuit 105 and the like based on the various timing signals generated by the timing generator.

[0126] The signal processing unit 106 has at least an arithmetic operation processing function, and the signal processing unit 106 performs various types of signal processing (e.g., arithmetic operation processing) based on the pixel signal output from the column processing circuit 104, and outputs the distance information of each pixel calculated by the signal processing to the outside. The data storage unit 107 temporarily stores data required for the signal processing in the signal processing unit 106.

[0127] 1.3 Example of circuit configuration of unit pixel

[0128] Figure 3 is a circuit diagram showing an example of an equivalent circuit of a unit pixel according to the present embodiment. Figure 3 As shown, the unit pixel 20 has the following structure: in one signal extraction unit 30A of two signal extraction units 30A and 30B formed in a semiconductor substrate 40, a voltage for charge readout (hereinafter referred to as a readout voltage) VmixA is applied to a p+ semiconductor region (hereinafter referred to as MIX) 21, and a readout circuit 20A including a transfer transistor 24, an FD 26, a reset transistor 23, an amplifying transistor 27 and a selecting transistor 28 is connected to an n+ semiconductor region (hereinafter referred to as DET) 22.

[0129] Likewise, the unit pixel 20 has a configuration in which a readout voltage VmixB is applied to the MIX 21 in another signal extraction section 30B, and a readout circuit 20B including a transfer transistor 24 , an FD 26 , a reset transistor 23 , an amplification transistor 27 , and a selection transistor 28 is connected to the DET 22 .

[0130] Furthermore, the two signal extraction sections 30A and 30B in the semiconductor substrate 40 are PN semiconductor regions including the MIX 21 and the DET 22 , and the region including the two signal extraction sections 30A and 30B functions as a light receiving element of each unit pixel 20 .

[0131] The vertical drive circuit 103 applies a readout voltage VmixA to the MIX 21 of the signal extraction section 30A and applies a readout voltage VmixB to the MIX 21 of the signal extraction section 30B. For example, when extracting a signal (charge) from the signal extraction section 30A, the vertical drive circuit 103 applies a readout voltage VmixA of 1.5 V (volts) to the MIX 21 of the signal extraction section 30A and applies a readout voltage VmixB of 0 V to the MIX 21 of the signal extraction section 30B. On the other hand, when extracting a signal (charge) from the signal extraction section 30B, the vertical drive circuit 103 applies a readout voltage VmixB of 1.5 V (volts) to the MIX 21 of the signal extraction section 30B and applies a readout voltage VmixA of 0 V to the MIX 21 of the signal extraction section 30A.

[0132] The DET 22 in each of the signal extraction sections 30A and 30B is a charge detection section that detects and accumulates charges generated according to photoelectric conversion of light incident on the semiconductor substrate 40 .

[0133] In each of the readout circuits 20A and 20B, the transfer transistor 24 switches to an on state in response to the activation state of the drive signal TRG supplied to the gate thereof from the vertical drive circuit 103 , thereby transferring the charge accumulated in the DET 22 corresponding thereto to the FD 26 .

[0134] The FD 26 has a charge-voltage conversion function that generates a voltage having a voltage value corresponding to the accumulated charge, and applies a voltage having a voltage value corresponding to the charge amount to the gate of the amplification transistor 27 by temporarily holding the charge transferred from the DET 22 .

[0135] The reset transistor 23 is switched to a conductive state in response to the activation state of the drive signal RST supplied to its gate from the vertical drive circuit 103, thereby resetting the potential of the FD 26 to a predetermined level (reset level VDD). In addition, when the reset transistor 23 is switched to an active state to reset the charge accumulated in the DET 22, the transfer transistor 24 may also be switched to an active state.

[0136] The source of the amplifier transistor 27 is connected to the vertical signal line VSL0 / VSL1 via the selection transistor 28 , and constitutes a source follower circuit together with the load MOS transistor of the constant current circuit 29A / 29B connected to one end of the vertical signal line VSL0 / VSL1 .

[0137] The selection transistor 28 is connected between the source of the amplifier transistor 27 and the vertical signal line VSL0 / VSL1. The selection transistor 28 switches to a conductive state in response to the activation state of the selection signal SEL supplied to its gate from the vertical drive circuit 103, and outputs the pixel signal output from the amplifier transistor 27 to the vertical signal line VSL0 / VSL1.

[0138] 1.4 Example of unit pixel readout operation

[0139] Then, reference will be made to Figure 3 etc. describe in detail a readout operation when measuring the distance to a target object according to the indirect ToF method using the solid-state imaging device 100 having the above-described structure.

[0140] When the distance to the target object is measured according to the indirect ToF method, the light emitting unit 13 (reference Figure 1 ) emits light having a specific wavelength (e.g., infrared light) toward a target object. Then, when the light is reflected by the target object and incident on the light receiving unit 14 as reflected light, the semiconductor substrate 40 of the solid-state imaging device 100 performs photoelectric conversion on the incident reflected light to generate electric charge corresponding to the amount of light.

[0141] Here, the vertical driving circuit 103 drives the unit pixel 20 , and distributes a signal corresponding to the charge obtained by the photoelectric conversion to the FDs 26 of the two readout circuits 20A and 20B.

[0142] For example, the vertical drive circuit 103 applies a voltage to two MIX 21 in the same unit pixel 20 at a specific time. Specifically, for example, the vertical drive circuit 103 applies a readout voltage VmixA of 1.5V (volts) to the MIX 21 of the signal extraction section 30A, and applies a readout voltage VmixB of 0V to the MIX 21 of the signal extraction section 30B.

[0143] In this state, when light is incident into the semiconductor substrate 40 through the on-chip lens 45 and charges are generated according to photoelectric conversion of the light, the generated charges are guided to move to the MIX 21 of the signal extraction section 30A and are accumulated in the DET 22 of the signal extraction section 30A.

[0144] In this case, the charges (ie, electrons) generated by the photoelectric conversion are used as signal carriers for detecting the amount of light incident on the light receiving element 31 , ie, a signal corresponding to the amount of received light.

[0145] The charges accumulated in the DET 22 of the signal extraction section 30A are transferred to the FD 26 through the transfer transistor 24 of the readout circuit 20A. Therefore, a voltage having a voltage value corresponding to the charges accumulated in the FD 26 is applied to the gate of the amplifier transistor 27 in the readout circuit 20A, and as a result, a voltage having a voltage value corresponding to the amount of charges accumulated in the FD 26 appears on the vertical signal line VSL0 through the selection transistor 28.

[0146] The voltage appearing on the vertical signal line VSL0 is read out by the column processing circuit 104 as a digital pixel signal, and is input to the signal processing unit 106 .

[0147] In addition, at the next moment, a voltage is applied to the two MIX 21 of the light receiving element 31 so that an electric field is generated in a direction opposite to the direction of the electric field generated in the light receiving element 31 until that point in time. Specifically, for example, the vertical drive circuit 103 applies a readout voltage VmixB of 1.5 V (volts) to the MIX 21 of the signal extraction section 30B, and applies a readout voltage VmixA of 0 V to the MIX 21 of the signal extraction section 30A.

[0148] In this state, when light is incident into the semiconductor substrate 40 through the on-chip lens 45 and charges are generated according to the photoelectric conversion of the light, these generated charges are guided to move to the MIX 21 of the signal extraction section 30B and are gathered in the DET 22 of the signal extraction section 30B. In addition, as described above, the signal carriers may be electrons.

[0149] The charges accumulated in the DET 22 of the signal extraction section 30B are transferred to the FD 26 through the transfer transistor 24 of the readout circuit 20B. Therefore, a voltage having a voltage value corresponding to the charges accumulated in the FD 26 is applied to the gate of the amplifier transistor 27 in the readout circuit 20B, and as a result, a voltage having a voltage value corresponding to the amount of charges accumulated in the FD 26 appears on the vertical signal line VSL1 through the selection transistor 28.

[0150] The voltage appearing on the vertical signal line VSL1 is read out by the column processing circuit 104 as a digital pixel signal, and is input to the signal processing unit 106 .

[0151] For example, the signal processing unit 106 calculates distance information indicating the distance to the target object based on the difference between the pixel signals read out by the two readout circuits 20A and 20B, and outputs the calculated distance information to the outside.

[0152] As described above, a method of distributing signal carriers to the two signal extraction sections 30A and 30B and calculating distance information based on pixel signals read out by the readout circuits 20A and 20B is referred to as an indirect ToF method.

[0153] 1.5 Example of chip configuration

[0154] Figure 4 1 is a diagram showing an example of a chip configuration of a solid-state imaging device according to this embodiment. Figure 4 As shown, the solid-state imaging device 100 has a structure of a stacked chip 50, which has, for example, a light receiving chip 51 and a circuit chip 52 stacked up and down. The light receiving chip 51 is, for example, a semiconductor chip including a semiconductor substrate 40 used as a light receiving element in the unit pixel 20, and the circuit chip 52 is, for example, a semiconductor chip in which the readout circuits 20A and 20B in the unit pixel 20 and peripheral circuits and the like are formed.

[0155] In order to bond the light receiving chip 51 and the circuit chip 52, for example, so-called direct bonding can be used, in which the bonding surfaces of the light receiving chip 51 and the circuit chip 52 are flattened and they are bonded using the force between electrons. However, the present disclosure is not limited thereto, and so-called Cu-Cu bonding and bump bonding, for example, in which electrode pads made of copper (Cu) formed on the mutual bonding surfaces are bonded, etc. may also be used.

[0156] In addition, for example, the light receiving chip 51 and the circuit chip 52 are electrically connected through a connection portion such as a through-silicon via (TSV) penetrating the semiconductor substrate. For connection using TSV, for example, a so-called double TSV method can be used, in which two TSVs (i.e., a TSV provided in the light receiving chip 51 and a TSV provided from the light receiving chip 51 to the circuit chip 52) are connected to the outer surface of the chip; and a so-called shared TSV method, in which the light receiving chip 51 and the circuit chip 52 are connected using a TSV penetrating from the light receiving chip 51 to the circuit chip 52.

[0157] However, when Cu-Cu bonding or bump bonding is used for bonding of the light receiving chip 51 and the circuit chip 52 , the light receiving chip 51 and the circuit chip 52 are electrically connected through the Cu-Cu bonding portion and the bump bonding portion.

[0158] Furthermore, in addition to the solid-state imaging device 100, Figure 4 The stacked chip 50 shown may further include an arithmetic operation unit 15 , a light emitting unit 13 , a control unit 11 and the like.

[0159] 1.6 Example of Planar Layout of Light Receiving Element

[0160] Subsequently, a planar layout example of the light receiving element 31 in the pixel array unit 101 will be described in detail with reference to the drawings. Figure 5 : is a plan view showing an example of the layout of the light receiving element according to the present embodiment. Figure 6 It is shown Figure 5 A plan view showing an example of the dimensions of a light receiving element.

[0161] like Figure 5 As shown, the pixel array unit 101 has a configuration in which a plurality of light receiving elements 31 are arranged in a two-dimensional lattice shape. For example, each light receiving element 31 includes two signal extraction sections 30A and 30B arranged separately in the column direction near the center thereof. For example, each signal extraction section 30A / 30B includes a MIX 21 having a circular cross section along the arrangement plane of the light receiving element 31 and a DET 22 arranged to surround the MIX 21.

[0162] Here, if Figure 6 As shown, when the distance between the centers of the signal extraction sections 30A and 30B in each light receiving element 31 is a, each light receiving element 31 is arranged in a rectangular region having a length of 2a in the column direction, for example. Figure 6 The length of the area of ​​the light receiving element 31 in the row direction is also 2a and is shown in a square shape, but the area is not limited to the square shape and may have various modified shapes.

[0163] 1.7 Optical separation between light receiving elements

[0164] For example, in order to prevent light from leaking into adjacent pixels, a light shielding film may be provided at the boundary between the light receiving elements 31 arranged in a two-dimensional lattice in the pixel array unit 101 . Figure 7 : is a top view showing the positional relationship between the light receiving element and the light shielding film when the semiconductor substrate according to the present embodiment is viewed in a direction perpendicular to the light incident surface.

[0165] like Figure 7As shown, for example, the light shielding film 44 is provided in a lattice along the boundaries BV and BH of the plurality of light receiving elements 31 arranged in a two-dimensional lattice. In this case, the openings formed by the light shielding film 44 are arranged in a two-dimensional lattice.

[0166] In addition, if Figure 7 As shown, the signal extraction sections 30A and 30B in each light receiving element 31 are formed, for example, in a region adjacent to or overlapping with an edge of an opening of the light shielding film 44 when viewed in a direction perpendicular to the light incident surface in the semiconductor substrate 40 .

[0167] However, if Figure 8 As shown, when the shading film 44 is provided only on the light incident surface of the semiconductor substrate 40 (the upper surface side in the figure, corresponding to the back side of the semiconductor substrate 40), there is a possibility that the incident light L10 incident on the portion 41a for electrically separating the MIX 21 and the DET22 of each signal extraction unit 30A / 30B in the insulating layer 41 formed on the front surface side (the lower surface side in the figure) of the semiconductor substrate 40 is diffusely reflected and the reflected light L11 of the incident light L10 is incident on the light receiving element 31 of the adjacent pixel, thereby causing color mixing.

[0168] Therefore, in this embodiment, if later using Fig. 9 and Fig.10 As described above, a pixel separation section for optically separating between the light receiving elements 31 is provided. Therefore, color mixing caused by leakage of the reflected light L11 diffusely reflected by the portion 41a into the adjacent pixel is reduced, thereby improving the pixel separation characteristics of optical separation between the light receiving elements 31. On the other hand, Figure 8 It shows that the Fig. 9 The example of the structure shown is an example of a cross-sectional structure in which the pixel separation portion is omitted.

[0169] 1.8 Example of cross-sectional structure of unit pixel

[0170] Fig. 9 : is a cross-sectional view showing a schematic configuration example of a light receiving element according to the present embodiment. Fig. 9 An example of a cross-sectional structure of a portion of a light receiving chip 51 in a so-called back-illuminated solid-state imaging device 100 is shown, which corresponds to Figure 7 In addition, Fig.10 is shown when viewed in a direction perpendicular to the light incident surface Fig. 9 A top view showing the positional relationship between the light receiving element and the pixel separation portion on a semiconductor substrate shown.

[0171] First, if Fig. 9As shown, the light receiving element 31 in each unit pixel 20 includes, for example, a semiconductor substrate 40 such as a silicon substrate having a p-type well (p-well), an anti-reflection film 42 provided on the back side (upper surface side in the figure) of the semiconductor substrate 40, a planarization film 43 provided on the anti-reflection film 42, and an on-chip lens 45 provided on the planarization film 43. In addition, the circuit chip 52 may be bonded to the front surface side (lower surface side in the figure) of the semiconductor substrate 40 via an insulating layer 41 such as a silicon oxide layer.

[0172] In addition, a light shielding film 44 for preventing color mixing between adjacent pixels is provided on the planarization film 43 at the boundary between adjacent light receiving elements 31. For example, the light shielding film 44 can be made of a material having a light shielding property, such as tungsten (W).

[0173] In addition, if Fig. 9 and Fig.10 As shown, for example, a pixel separation section 46 for optically separating adjacent light receiving elements 31 is provided at the boundaries BV and BH of the light receiving elements 31 in the semiconductor substrate 40. In other words, the pixel separation section 46 optically divides the semiconductor substrate 40 into a plurality of pixel regions (corresponding to the light receiving elements 31) arranged in a matrix. For example, these pixel separation sections 46 may be reverse deep trench isolation (RDTI: reverse deep trench isolation) type pixel separation sections protruding from the back surface (upper surface in the figure) of the semiconductor substrate 40 to the front surface side (lower surface in the figure).

[0174] In addition, if Fig.10 As shown, these pixel separation parts 46 may be arranged in a lattice along the boundaries BV and BH of the light receiving element 31. In this case, the pixel separation parts 46 are arranged at positions corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the pixel separation parts 46 are covered by the light shielding film 44.

[0175] Furthermore, the pixel separation section 46 and the semiconductor substrate 40 may be electrically separated from each other using an insulating layer etc. This is the same in the pixel separation section in the embodiment to be described later.

[0176] A semiconductor substrate such as a silicon substrate can be used as the semiconductor substrate 40, and its substrate thickness can be reduced to, for example, 20 μm (micrometers) or less. In addition, the thickness of the semiconductor substrate 40 can be equal to or greater than 20 μm, and can be appropriately set according to the characteristics, etc., targeted by the solid-state imaging device 100.

[0177] For example, the antireflection film 42 may be a film formed using a high refractive index material such as silicon oxynitride (SiON), etc. In addition, for example, the planarization film 43 may be a film formed using an insulating material such as silicon oxide (SiO2), etc.

[0178] For the pixel separation portion 46 , a light shielding material such as tungsten (W) or a high refractive index material (for example, a material having a refractive index higher than that of the semiconductor substrate 40 ) may be used.

[0179] A pair of signal extraction sections 30A and 30B are provided in a region on the front surface side (lower surface side in the drawing) of the semiconductor substrate 40 .

[0180] Here, for example, MIX 21 in each signal extraction section 30A / 30B may be a region where an acceptor such as boron (B) is diffused in the semiconductor substrate 40 , and DET may be a region where a donor such as phosphorus (P) or arsenic (As) is diffused in the semiconductor substrate 40 .

[0181] The DET of each signal extraction section 30A / 30B functions as a charge detection section for detecting the amount of light incident on the light receiving element 31 from the outside, that is, the amount of charge generated according to photoelectric conversion of the semiconductor substrate 40 .

[0182] On the other hand, the MIX 21 functions as a voltage applying section for injecting most of the carrier current into the semiconductor substrate 40 , that is, for applying a voltage directly to the semiconductor substrate 40 to generate an electric field in the semiconductor substrate 40 .

[0183] In the present embodiment, for example, the FD 26 of the readout circuit 20A or 20B is directly connected to the DET 22 of the signal extraction section 30A or 30B (refer to Figure 3 ).

[0184] In addition, for example, the on-chip lens 45 may use silicon oxide (SiO 2 ) or a transparent resin or the like, and the curvature of the on-chip lens 45 is set so that the incident light is focused near the center of the light receiving element 31 .

[0185] Since the incident light L10 is focused near the center of each light receiving element 31 by the on-chip lens 45, the photoelectric conversion of the incident light L10 near the signal extraction section 30A or 30B is reduced, so that excessive photoelectric conversion can be suppressed. Therefore, it is possible to reduce the inflow of unexpected charges into the DET 22 of the signal extraction section 30A or 30B, so that the pixel separation characteristics can be further improved.

[0186] 1.9 Function and Effect

[0187] As described above, according to the present embodiment, the pixel separation section 46 is provided between the light receiving elements 31, thereby being able to reduce the color mixing caused by the reflected light L11 diffusely reflected by the portion 41a leaking into the adjacent pixel. As a result, the pixel separation characteristics of the optical separation between the light receiving elements 31 are improved, thereby being able to suppress the reduction of the ranging accuracy.

[0188] In addition, although the case where the semiconductor substrate 40 is a p-type well, the MIX 21 is a p+ semiconductor region of conductivity type p, and the DET 22 is an n+ semiconductor region of conductivity type n is exemplified in the present embodiment, the present disclosure is not limited thereto, and for example, the semiconductor substrate 40 may be an n-type well, the MIX 21 may be an n+ semiconductor region of conductivity type n, and the DET 22 may be a p+ semiconductor region of conductivity type p. The same applies to the embodiments to be described later.

[0189] 1.10 Modification of Pixel Separation Unit

[0190] In addition, although the so-called RDTI type pixel separation unit 46 formed from the back surface (upper surface in the figure) to the middle of the semiconductor substrate 40 is exemplified in this embodiment, the present disclosure is not limited thereto. Therefore, some modified examples of the pixel separation unit will be exemplified below.

[0191] 1.10.1 First Modification

[0192] Fig.11 : is a cross-sectional view showing a schematic configuration example of a light receiving element according to a first modification. Fig.11 It shows that Fig. 9 An example of a cross-sectional structure of a portion of a light receiving chip 51 in a so-called back-illuminated solid-state imaging device 100 as in Figure 7 Section AA in.

[0193] like Fig.11 As shown, the light receiving element 31 according to the first modification has a cross-sectional structure as follows: Fig. 9 The pixel separation section 46 illustrated in FIG. 1 has been replaced by, for example, a DTI type pixel separation section 46a protruding from the front surface (lower surface in the figure) toward the back side (upper surface in the figure) of the semiconductor substrate 40. Like the pixel separation section 46, these pixel separation sections 46a may be arranged in a lattice along the boundaries BV and BH of the light receiving element 31 (see FIG. Fig.10 ).

[0194] In this way, it is also possible to reduce color mixing caused by leakage of reflected light L11 diffusely reflected by portion 41a into adjacent pixels by the DTI type pixel separation portion 46a formed from the front surface side of the semiconductor substrate 40. Therefore, the pixel separation characteristics of the optical separation between the light receiving elements 31 are improved, thereby being able to suppress a reduction in the ranging accuracy.

[0195] 1.10.2 Second Modification

[0196] Fig.12 : is a cross-sectional view showing a schematic configuration example of a light receiving element according to a second modification. Fig.12 It shows that Fig. 9 and Fig.11 An example of a cross-sectional structure of a portion of a light receiving chip 51 in a so-called back-illuminated solid-state imaging device 100 as in Figure 7 Section AA in.

[0197] like Fig.12 As shown, the light receiving element 31 according to the second modification has a cross-sectional structure as follows: Fig. 9 The pixel separators 46 illustrated in FIG. 4 have been replaced by, for example, front full trench isolation (FFTI: front full trench isolation) type pixel separators 46 b that penetrate the front and back surfaces of the semiconductor substrate 40. Like the pixel separators 46, these pixel separators 46 b may be arranged in a lattice along the boundaries BV and BH of the light receiving elements 31 (see FIG. 4 ). Fig.10 ).

[0198] In this way, the pixel separation characteristics can be further improved by performing optical separation between the light receiving elements 31 using the FFTI type pixel separation section 46 b penetrating the front and back surfaces of the semiconductor substrate 40 , thereby being able to suppress a decrease in distance measurement accuracy.

[0199] 2. Second Implementation Method

[0200] Next, the second embodiment will be described in detail below with reference to the accompanying drawings. On the other hand, by citing the above embodiment in the following description, repeated description of the same configuration, action and effect as the above embodiment will be omitted.

[0201] 2.1 Example of planar layout of light receiving element

[0202] Fig.13 is a plan view showing an example of the layout of the light receiving element according to the present embodiment, and Fig.14 It is shown Fig.13 A plan view showing an example of the dimensions of a light receiving element.

[0203] like Fig.13 As shown, the pixel array unit 101 according to the present embodiment has a configuration in which a plurality of light receiving elements 231 are arranged in a two-dimensional lattice shape. PN semiconductor regions 230 are provided at respective boundaries of the light receiving elements 231 in the column direction (vertical direction in the figure).

[0204] For example, each PN semiconductor region 230 includes a MIX 21 located at each boundary of the light receiving element 231, a DET 22A adjacent to the MIX 21 below the MIX 21 in the column direction, and a DET 22B adjacent to the MIX 21 above the MIX 21 in the column direction. For example, the lengths of the DET 22A and the DET 22B in the row direction relative to the MIX 21 may be shorter than the length of the MIX 21 in the row direction. In this case, since the influence of the DET 22A and the DET 22B on the electric field formed by the two MIX 21 in the light receiving element 231 can be reduced, charges can be effectively collected in the DET 22A or 22B, so that the reduction in quantum efficiency can be suppressed.

[0205] In this configuration, the MIX 21 and the DET 22A in each PN semiconductor region 230 constitute a signal extraction section 30A for the lower light receiving element 231 of the two light receiving elements 231 forming each boundary, and the MIX 21 and the DET 22B constitute a signal extraction section 30B for the upper light receiving element 231. That is, the MIX 21 located at the boundary between the two light receiving elements 231 is shared by the two light receiving elements 231.

[0206] Here, when the distance between the centers of the MIX 21 in the signal extraction sections 30A and 30B is a as in the light receiving element 31 according to the first embodiment, Fig.14 As shown, each light receiving element 231 can be a rectangular area having a length a in the column direction. That is, as in the present embodiment, by adopting a configuration in which two vertically adjacent light receiving elements 231 share MIX 21, the distance between the centers of MIX 21 can be set as the pixel pitch of the light receiving element 231. Therefore, since the integration of the light receiving element 231 in the column direction can be improved, the resolution in the column direction can be improved. Here, for example, by forming the plane area of ​​the light receiving element 231 into a square, the resolution in the row direction can also be doubled.

[0207] 2.2 Example of Planar Layout of Pixel Separation Unit

[0208] Next, some examples of the planar layout of the pixel separation section 246 according to the present embodiment will be illustrated.

[0209] 2.2.1 First Example

[0210] Fig.15 is a diagram showing a planar layout example of a pixel separation portion according to a first example and is a top view showing a positional relationship between a light receiving element and a pixel separation portion when the semiconductor substrate according to the present embodiment is observed in a direction perpendicular to a light incident surface. Fig.16 It is shown Fig.15 A cross-sectional view of an example of a cross-sectional structure of a plane BB in FIG. Fig.17 It is shown Fig.15 A cross-sectional view of an example of a cross-sectional structure in plane CC.

[0211] like Fig.15 As shown, for example, the pixel separation section 246 according to the first example is formed along the boundary BV extending in the column direction among the boundaries BV and BH of the light receiving element 231 .

[0212] In this case, if Fig.16 As shown, for example, on a plane BB near the center of the light receiving element 231 cut along the row direction, an RDTI type pixel separation portion 246 protruding from the back side (upper surface in the figure) of the semiconductor substrate 40 to the front surface side (lower surface in the figure) appears at the boundary BV in the column direction of the light receiving element 231.

[0213] The pixel separation section 246 is provided at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the pixel separation section 246 is covered by a portion of the light shielding film 44 extending in the column direction.

[0214] In addition, the RDTI type pixel separation portion 246 protruding from the back surface to the front surface side of the semiconductor substrate 40 can be deformed in various ways to a DTI type pixel separation portion protruding from the front surface to the back surface of the semiconductor substrate 40 (refer to Fig.11 ) and the FFTI type pixel separation portion that penetrates the front surface and the back surface of the semiconductor substrate 40 (reference Fig.12 )wait.

[0215] On the other hand, Fig.17 As shown, for example, on a plane CC cutting near the center of the light receiving element 231 in the column direction, MIX 21 appears at a boundary BH in the row direction of the light receiving element 231, and DET 22A and DET 22B appear at a position where MIX 21 is interposed between DET 22A and DET 22B.

[0216] In this case, the PN semiconductor region 230 including the MIX 21, the DET 22A, and the DET 22B is disposed at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is observed in a direction perpendicular to the light incident surface, the PN semiconductor region 230 is covered by a portion of the light shielding film 44 extending in the row direction.

[0217] As described above, by providing the pixel separator 246 between the light receiving elements 231 adjacent in the row direction, leakage of the reflected light L11 into the light receiving elements 231 adjacent in the row direction can be reduced. Therefore, the pixel separation characteristics of the optical separation between the light receiving elements 231 are improved, thereby suppressing the reduction of the distance measurement accuracy.

[0218] 2.2.2 Second Example

[0219] Fig.18 is a diagram showing a planar layout example of a pixel separation portion according to a second example and is a top view showing a positional relationship between a light receiving element and a pixel separation portion when the semiconductor substrate according to the present embodiment is observed in a direction perpendicular to a light incident surface. Fig.19 It is shown Fig.18 A cross-sectional view of an example of a cross-sectional structure in plane DD.

[0220] like Fig.18 As shown, for example, in the second example, the pixel separation sections 246 a are arranged in a lattice along the boundaries BV and BH of the light receiving element 231 .

[0221] In this case, for example, Fig.19 As shown, on the plane DD cutting the light receiving element 231 in the column direction, there appear the PN semiconductor region 230 located at the boundary BH in the row direction of the light receiving element 231 and the RDTI type pixel separation portion 246a protruding from the back surface (upper surface in the figure) to the front surface side (lower surface in the figure) of the semiconductor substrate 40. In addition, for example, the cross-sectional structure of the plane cutting the light receiving element 231 in the center can be the same as that used in the first example. Fig.17 The cross-sectional structure described is the same.

[0222] The pixel separation portion 246a is provided at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the lattice-shaped pixel separation portion 246a is covered by the lattice-shaped light shielding film 44.

[0223] In addition, the RDTI type pixel separation portion 246a protruding from the back surface to the front surface side of the semiconductor substrate 40 can be deformed in various ways to a DTI type pixel separation portion protruding from the front surface to the back surface of the semiconductor substrate 40 (refer to Fig.11 ) and the FFTI type pixel separation portion that penetrates the front surface and the back surface of the semiconductor substrate 40 (reference Fig.12 ) etc. However, when the FFTI type is adopted, as in a third example to be described later, the portion intersecting (overlapping) the PN semiconductor region 230 may be cut off, or the portion overlapping the PN semiconductor region 230 may be constructed as an RDTI type.

[0224] As described above, by surrounding each light receiving element 231 with the grid-shaped pixel separator 246a, leakage of the reflected light L11 in the column direction and the row direction can be reduced. Therefore, the pixel separation characteristics of optical separation between the light receiving elements 231 are improved, and the reduction in distance measurement accuracy can be further suppressed.

[0225] 2.2.3 Third Example

[0226] Fig. 20 is a diagram showing a planar layout example of a pixel separation portion according to a third example and is a top view showing a positional relationship between a light receiving element and a pixel separation portion when the semiconductor substrate according to the present embodiment is observed in a direction perpendicular to a light incident surface.

[0227] like Fig. 20 As shown, for example, in the same configuration as the pixel separation portion 246a according to the second example, the pixel separation portion 246b according to the third example has a shape in which a portion intersecting (overlapping) with the PN semiconductor region 230 is cut off.

[0228] In this case, for example, if you use Fig.19 As described in the second example of FIG. 1 , on a plane cutting the vicinity of the center of the light receiving element 231 in the column direction, there appears a PN semiconductor region 230 located at the boundary BH in the row direction of the light receiving element 231 and an RDTI type pixel separation portion 246 b protruding from the back surface (upper surface in the figure) toward the front surface side (lower surface in the figure) of the semiconductor substrate 40. In addition, for example, the cross-sectional structure of the plane cutting the vicinity of the center of the light receiving element 231 may be different from that used in the first example. Fig.17 The cross-sectional structure described is the same.

[0229] The pixel separation portion 246b is provided at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the pixel separation portion 246b is covered by the light shielding film 44 in a grid shape.

[0230] In addition, the RDTI type pixel separation portion 246b protruding from the back surface to the front surface side of the semiconductor substrate 40 can be transformed into a DTI type pixel separation portion protruding from the front surface to the back surface of the semiconductor substrate 40 in various ways (refer to Fig.11 ) and the FFTI type pixel separation portion that penetrates the front surface and the back surface of the semiconductor substrate 40 (reference Fig.12 )wait.

[0231] As described above, since in a structure in which each light receiving element 231 is surrounded by a grid-shaped pixel separation portion 246b, the influence of the pixel separation portion 246b on the electric field formed by the two MIX 21 in each light receiving element 231 can be reduced by cutting off the area corresponding to the PN semiconductor region 230, charges can be effectively collected into DET 22A or 22B, thereby suppressing the reduction in quantum efficiency.

[0232] 2.3 Function and Effect

[0233] As described above, according to the present embodiment, since two vertically adjacent unit pixels 20 share one MIX 21, the distance between the centers of the MIX 21 can be set as is to the pixel pitch of the unit pixels 20. Therefore, since the integration degree of the unit pixels 20 in the column direction can be increased, the ranging accuracy can be improved while suppressing the reduction of the resolution, or the resolution can be improved while suppressing the reduction of the ranging accuracy.

[0234] In addition, according to the present embodiment, the strong electric field region formed around the signal extraction section 30B or 30A which is not the signal extraction side can be reduced. Therefore, in the present embodiment, the charges generated near the signal extraction section 30B or 30A which is not the signal extraction side can also be effectively gathered in the DET 22A of the signal extraction section 30A on the signal extraction side or the DET 22B of the signal extraction section 30B, and therefore, the substantial quantum efficiency can be improved to improve the contrast between pixels.

[0235] Furthermore, according to the present embodiment, since charges can be efficiently collected from a wide range of the semiconductor substrate 40 into the DET 22A or 22B on the signal extraction side, the effects of fast readout operation and readout at a low operating voltage can be obtained.

[0236] On the other hand, since other configurations, functions, and effects are the same as those in the above-mentioned embodiment, detailed descriptions thereof will be omitted.

[0237] 3. Third Implementation Plan

[0238] Next, the third embodiment will be described in detail below with reference to the drawings. On the other hand, by citing the above embodiment in the following description, repeated description of the same configuration, action and effect as the above embodiment will be omitted.

[0239] In the second embodiment, the case where two light receiving elements 231 arranged in the column direction share one MIX 21 has been exemplified. On the other hand, in the third embodiment, the case where four light receiving elements 231 adjacent in the column direction and the row direction share one MIX 21 will be exemplified.

[0240] 3.1 Example of Planar Layout of Light Receiving Element

[0241] Fig.21 is a plan view showing an example of the layout of the light receiving element according to the present embodiment, Fig. 22 It is shown Fig.21 A plan view showing an example of the dimensions of a light receiving element.

[0242] like Fig.21 As shown, as in the second embodiment, the pixel array unit 101 according to the present embodiment has a configuration in which a plurality of light receiving elements 331 are arranged in a two-dimensional lattice shape.

[0243] However, in the present embodiment, the four light receiving elements 331 arranged in 2×2 in the column direction and the row direction are divided into one group, and the MIX 21 is respectively provided at the center portion where the corners of the four light receiving elements 331 are concentrated and at the four corners of the rectangular area formed by the four light receiving elements 331. In other words, each MIX 21 is provided so that it is provided at a pair of opposite corners in each light receiving element 331. In addition, the MIX 21 provided at each of the four corners of the rectangular area formed by the four light receiving elements 331 is shared by the four light receiving elements 331 having the MIX 21 at the center.

[0244] Each MIX 21 constitutes a signal extraction section 30A or 30B together with the DET 22A or 22B respectively provided in four light receiving elements 331 sharing the MIX 21. Therefore, the PN semiconductor region 330 according to the present embodiment includes two signal extraction sections 30A and two signal extraction sections 30B.

[0245] The positions of the DETs 22A and 22B in each light receiving element 331 may be the same as in the second embodiment, for example, positions near the center of the boundary in the column direction of each light receiving element 331 .

[0246] Here, when the distance between the centers of the MIX 21 in the signal extraction sections 30A and 30B is a and the area in which each light receiving element 331 is formed is a square, like the light receiving element 231 according to the second embodiment, for example, Fig. 22 As shown, each light receiving element 331 can be formed in a square area having a length of a / √2 in the column direction and the row direction. That is, as in the present embodiment, by adopting a configuration in which four light receiving elements 331 arranged in two rows and two columns share one MIX 21, the pixel pitch of the light receiving element 331 can be set to 1 / √2 of the pixel pitch a in the second embodiment. Therefore, since the integration of the light receiving element 331 in the column direction and the row direction can be improved, the resolution in the column direction and the row direction can be improved. In addition, when the plane area of ​​the light receiving element 231 according to the second embodiment is a square, the resolution in the row direction can also be √2 times.

[0247] 3.2 Example of Planar Layout of Pixel Separation Unit

[0248] Next, some examples of the planar layout of the pixel separation section 346 according to the present embodiment will be illustrated.

[0249] 3.2.1 First Example

[0250] Fig.23 is a diagram showing a planar layout example of a pixel separation portion according to a first example and is a top view showing a positional relationship between a light receiving element and a pixel separation portion when the semiconductor substrate according to the present embodiment is observed in a direction perpendicular to a light incident surface. Fig.24 It is shown Fig.23 A cross-sectional view of an example of a cross-sectional structure in plane EE.

[0251] like Fig.23 As shown, in the first example, for example, like the pixel separation section 246 a according to the second example of the second embodiment, a lattice-shaped pixel separation section 346 is provided along the boundaries BV and BH of the light receiving element 331 .

[0252] In this case, for example, Fig.24 As shown, on a plane cut along the column direction near the center of the light receiving element 331, the DETs 22A and 22B located near the boundary BH in the row direction of the light receiving element 331 and the RDTI type pixel separation portion 346 protruding from the back surface (upper surface in the figure) toward the front surface side (lower surface side in the figure) of the semiconductor substrate 40 appear. In addition, for example, the cross-sectional structure of the plane cut along the column direction near the center of the light receiving element 331 can be the same as that used in the first example of the second embodiment. Fig.17 The cross-sectional structure described is the same.

[0253] The pixel separation section 346 is provided at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the grid-shaped pixel separation section 346 is covered by the light shielding film 44 which is also grid-shaped.

[0254] In addition, the RDTI type pixel separation portion 346 protruding from the back surface to the front surface side of the semiconductor substrate 40 can be deformed in various ways to a DTI type pixel separation portion protruding from the front surface to the back surface of the semiconductor substrate 40 (refer to Fig.11 ) and the FFTI type pixel separation portion that penetrates the front surface and the back surface of the semiconductor substrate 40 (reference Fig.12 ) etc. However, when the FFTI type is adopted, as in a second example to be described later, the portion intersecting (overlapping) the PN semiconductor region 330 may be cut off, or the portion overlapping the PN semiconductor region 330 may be constructed as an RDTI type.

[0255] As described above, the leakage of the reflected light L11 in the column and row directions can be reduced by surrounding each light receiving element 331 with the grid-shaped pixel separator 346. Therefore, the pixel separation characteristics of the optical separation between the light receiving elements 331 are improved, and the reduction in the distance measurement accuracy can be further suppressed.

[0256] 3.2.2 Second Example

[0257] Fig.25 is a diagram showing a planar layout example of a pixel separation portion according to a second example and is a top view showing a positional relationship between a light receiving element and a pixel separation portion when the semiconductor substrate according to the present embodiment is observed in a direction perpendicular to a light incident surface.

[0258] like Fig.25 As shown, in the same configuration as the pixel separation section 346 according to the first example, the pixel separation section 346a according to the second example has, for example, a shape in which an intersection portion overlapping with the MIX 21 is cut off.

[0259] In this case, for example, as in the first example, Fig.24 As described, on a plane cut along the column direction near the center of the light receiving element 331, the DETs 22A and 22B located near the boundary BH in the row direction of the light receiving element 331 and the RDTI type pixel separation portion 346a protruding from the back surface (upper surface in the figure) toward the front surface side (lower surface side in the figure) of the semiconductor substrate 40 appear. In addition, for example, the cross-sectional structure of the plane cut along the column direction near the center of the light receiving element 331 can be the same as that used in the first example of the second embodiment. Fig.17 The cross-sectional structure described is the same.

[0260] The pixel separation portion 346a is provided at a position corresponding to the light shielding film 44 across the back surface of the semiconductor substrate 40. That is, when the semiconductor substrate 40 is viewed in a direction perpendicular to the light incident surface, the pixel separation portion 346a is covered by the light shielding film 44 in a grid shape.

[0261] In addition, the RDTI type pixel separation portion 346a protruding from the back surface to the front surface side of the semiconductor substrate 40 can be deformed in various ways to a DTI type pixel separation portion protruding from the front surface to the back surface of the semiconductor substrate 40 (refer to Fig.11 ) and the FFTI type pixel separation portion that penetrates the front surface and the back surface of the semiconductor substrate 40 (reference Fig.12 )wait.

[0262] As described above, since in a structure in which each light receiving element 331 is surrounded by a grid-shaped pixel separation portion 346a, by cutting off the area corresponding to MIX 21, the influence of the pixel separation portion 346a on the electric field formed by two MIX 21 in each light receiving element 331 can be reduced, and thus charges can be effectively collected into DET 22A or 22B, thereby being able to suppress a reduction in quantum efficiency.

[0263] 3.3 Function and Effect

[0264] As described above, according to the present embodiment, since four vertically adjacent and horizontally adjacent light receiving elements 331 share one MIX 21 and the MIX 21 is located at opposite corners of each light receiving element 331, 1 / √2 times the distance between the centers of the MIX 21 can be set as the pixel pitch of the light receiving element 331. Therefore, the integration degree of the light receiving elements 331 in the column direction and the row direction can be increased, so that the distance measurement accuracy can be improved while suppressing the reduction of the resolution, or the resolution can be improved while suppressing the reduction of the distance measurement accuracy.

[0265] Since other structures, functions and effects are the same as those in the above-mentioned embodiment, their detailed description is omitted.

[0266] 4. Fourth Implementation Method

[0267] Although the case where the positions of the DETs 22A and 22B in each light receiving element 331 are, for example, positions near the center at the boundary of each light receiving element 331 in the column direction is exemplified in the third embodiment (refer to Fig.21 ), but the positions of the DETs 22A and 22B in each light receiving element 331 may be changed in various ways.

[0268] For example, Fig.26As shown, by arranging the DET 22A and 22B in each light receiving element 431 near the corner where the MIX 21 is provided, the charge moved to the MIX 21 to which the read voltage VmixA or VmixB is applied can be effectively gathered in the DET 22A or 22B, so that the substantial quantum efficiency can be improved and the contrast between pixels can be improved. In addition, in the present embodiment, each PN semiconductor region 430 includes two signal extraction sections 30A and two signal extraction sections 30B, like the PN semiconductor region 330 according to the third embodiment.

[0269] In addition, for example, Fig. 27 As shown, the pixel separation section for optical separation between the light receiving elements 431 according to the fourth embodiment may be configured as a pixel separation section 446 having the same configuration as the pixel separation section 346 according to the first example of the third embodiment, or as Fig.28 As shown, a pixel separation section 446a having the same configuration as the pixel separation section 346a according to the second example of the third embodiment is configured.

[0270] Since other structures, functions and effects are the same as those in the above-mentioned embodiment, their detailed description is omitted.

[0271] 5. Fifth Implementation Method

[0272] Next, the fifth embodiment will be described in detail below with reference to the drawings. On the other hand, by citing the above embodiment in the following description, repeated description of the same configuration, action and effect as the above embodiment will be omitted.

[0273] In this embodiment, a case where the charge is suppressed from flowing into DET 22 / 22A or 22B in the above-mentioned embodiment and the amount of current flowing at the time of reading is thus controlled to reduce power consumption will be described. On the other hand, although the case based on the first embodiment will be exemplified in the following description, the embodiment as a basis is not limited to the first embodiment and may be other embodiments.

[0274] like Fig.29 As shown, for example, when a positive readout voltage VmixA for signal extraction is applied to MIX 21 of the signal extraction section 30A and a 0 or negative readout voltage VmixB is applied to the signal extraction section 30B, electrons (electrons) generated according to the photoelectric conversion of light incident on the semiconductor substrate 40 are guided by the electric field formed in the light receiving element 31 to move toward the signal extraction section 30A, and then flow into the DET 22 of the signal extraction section 30A.

[0275] At this time, although a higher readout voltage VmixA or VmixB must be applied in order to improve the quantum efficiency by forming a strong electric field in all the light receiving elements 31, in this case, when photoelectric conversion occurs near the signal extraction unit 30A or 30B, a large amount of charge is generated near the signal extraction unit 30A or 30B, which may cause excessive current to flow and increase power consumption.

[0276] Therefore, in the present embodiment, by suppressing the flow of electric charges generated near the signal extraction section 30A or 30B, the generation of excessive current is suppressed and the increase in power consumption is reduced.

[0277] 5.1 Example of the structure of a light receiving element

[0278] Fig.30 is a plan view showing a layout example of the light receiving element according to the present embodiment. Fig.31 It is shown Fig.30 Cross-sectional view of an example of a cross-sectional structure in plane FF.

[0279] like Fig.30 and Fig.31 As shown, in each light receiving element 531 according to the present embodiment, for example, in the same configuration as the light receiving element 31 according to the first embodiment, a blocking region 501 is provided between two signal extracting sections 30A and 30B.

[0280] For example, the blocking region 501 may be a structure formed using a material having a dielectric constant different from that of the semiconductor substrate 40, such as an insulating material such as silicon oxide (SiO2), silicon nitride (SiN), or polycrystalline silicon (poly-Si); a reflective material that reflects light of a specific wavelength, such as tungsten (W); an absorbing material that absorbs light of a specific wavelength; or a high refractive index material. However, the blocking region 501 is not limited thereto and may be various deformed regions having high resistance by counter-doping an n-type dopant into a portion of the p-type well of the semiconductor substrate 40, etc. In addition, when the blocking region 501 uses a conductive material such as tungsten (W), an insulating layer may be provided around the blocking region 501 in order to electrically separate the blocking region 501 and the semiconductor substrate 40 from each other.

[0281] For example, the blocking region 501 is a square columnar region protruding from the front surface (lower surface in the figure) of the semiconductor substrate 40 to the back side (upper surface side in the figure), and its height (depth from the front surface of the semiconductor substrate 40) is, for example, greater than the height of the MIX 21 in the two signal extraction sections 30A and 30B, and its width in the row direction is, for example, greater than the width of the MIX 21 in the two signal extraction sections 30A and 30B. However, the blocking region 501 is not limited to these shapes and sizes, and may be located at least in a region where the intensity of the electric field formed between the signal extraction sections 30A and 30B is high.

[0282] 5.2 Function and Effect

[0283] As described above, when the barrier region 501 having a dielectric constant different from that of the semiconductor substrate 40 is formed between the signal extraction sections 30A and 30B, the potential distribution of the electric field formed by the two MIXs 21 in the light receiving element 531 is changed. Therefore, the movement of the charge generated in the strong electric field region can be suppressed, and the moving distance thereof can be extended, so that the generation of excessive current can be suppressed, and the increase in power consumption can be reduced.

[0284] In addition, for example, when the barrier region 501 uses a reflective material such as tungsten (W) or a high refractive index material, since the incident light L10 reflected from the barrier region 501 also becomes the object of photoelectric conversion, the quantum efficiency of the light receiving element 531 can be improved.

[0285] Since other configurations, functions and effects are the same as those of the above-mentioned embodiment, detailed description thereof will be omitted.

[0286] 5.3 Variations of the blocking area

[0287] In addition, although the case where the barrier region 501 has a square column shape is exemplified in the present embodiment, the shape of the barrier region 501 is not limited thereto. Therefore, some modified examples of the barrier region will be exemplified below.

[0288] 5.3.1 First Modification

[0289] Fig.32 FIG. 2 is a plan view showing a configuration example of a barrier region according to a first modification example. Fig.32 As shown, for example, the blocking region 502 may be a region having a cylindrical shape in which a cross section parallel to the surface of the semiconductor substrate 40 is circular. However, the blocking region 502 is not limited to the cylindrical shape and may have an elliptical cylindrical shape or the like.

[0290] 5.3.2 Second Modification

[0291] Fig.33FIG. 2 is a plan view showing a configuration example of a barrier region according to a second modification example. Fig.33 As shown, for example, the blocking region 503 may be a region having a polygonal column shape in which the shape of a cross section parallel to the surface of the semiconductor substrate 40 is a polygon such as a hexagon.

[0292] 5.3.3 Third variant

[0293] Fig.34 FIG. 4 is a cross-sectional view showing a configuration example of a barrier region according to a third modification example. Fig.34 As shown, for example, the blocking region 504 may be a region having a pyramidal shape in which a cross section perpendicular to the surface of the semiconductor substrate 40 is triangular. Here, as described above, the shape of the cross section parallel to the surface of the semiconductor substrate 40 may be circular (including elliptical) or polygonal. In addition, the blocking region 504 is not limited to a pyramidal shape, and may have a truncated pyramidal shape.

[0294] 5.3.4 Fourth Modification

[0295] Fig.35 FIG. 4 is a cross-sectional view showing a configuration example of a barrier region according to a fourth modification. Fig.35 As shown, the upper portion of the blocking region 505 may have a dome shape with a curvature. In addition, the shape other than the upper portion may be various shapes such as a cylindrical shape and a truncated cone shape. In addition, as described above, the shape of the cross section parallel to the surface of the semiconductor substrate 40 may be a circle (including an ellipse) or a polygon.

[0296] By forming the barrier region 505 having a curvature at the upper portion in this manner, light incident on the upper portion of the barrier region 505 can be reflected over a wide range of the light receiving element 531 , and thus the quantum efficiency of the light receiving element 531 can be improved.

[0297] 5.3.5 Fifth variant

[0298] Fig.36 FIG. 4 is a cross-sectional view showing a configuration example of a barrier region according to a fifth modification example. Fig.36 As shown, the upper surface of the blocking region 506 may be rough. In addition, the shape other than the upper surface may be various deformed shapes such as a cylindrical shape and a truncated cone shape. In addition, as described above, the shape of the cross section parallel to the surface of the semiconductor substrate 40 may be a circle (including an ellipse) or a polygon.

[0299] By roughening the upper surface of the barrier region 505 in this manner, light incident on the upper surface can be diffusely reflected toward a wide range of the light receiving element 531 , so that the quantum efficiency of the light receiving element 531 can be improved.

[0300] 6. Sixth Implementation Method

[0301] Next, the sixth embodiment will be described in detail below with reference to the accompanying drawings. Meanwhile, by citing the above embodiment in the following description, repeated description of the same configuration, action and effect as the above embodiment will be omitted.

[0302] Although the fifth embodiment exemplifies the case where the blocking area 501 is provided between the two signal extracting sections 30A and 30B, the location of the blocking area is not limited thereto. Therefore, in this embodiment, some examples of the area where the blocking area is provided and its shape will be exemplified.

[0303] 6.1 First Example

[0304] Fig.37 FIG. 1 is a plan view showing a configuration example of a barrier region according to a first example. Fig.37 As shown, for example, in addition to the region between the two signal extraction sections 30A and 30B, the blocking region 601 can be provided on the entire light receiving element 631 in a manner protruding from the front surface to the back surface side of the semiconductor substrate 40. That is, the blocking region 601 is also provided in a portion other than the region between the two signal extraction sections 30A and 30B in each light receiving element 631. For example, each blocking region 601 may also be the same as the blocking region 501 according to the fifth embodiment and its modified example.

[0305] 6.2 Second Example

[0306] Fig.38 FIG. 2 is a plan view showing a configuration example of a barrier region according to a second example. Fig.38 As shown, for example, the blocking area 602 may be an area including a plurality of rows extending in the row direction over the entire light receiving element 631 except for the area where the two signal extracting sections 30A and 30B exist.

[0307] 6.3 Third Example

[0308] Fig.39 FIG. 2 is a plan view showing a configuration example of a barrier region according to a third example. Fig.39 As shown, for example, the blocking area 603 may be an area including a plurality of columns extending in the column direction over the entire light receiving element 631 except for the area where the two signal extracting sections 30A and 30B exist.

[0309] 6.4 Fourth Example

[0310] Fig.40 FIG. 4 is a plan view showing a configuration example of a barrier region according to a fourth example. Fig.40As shown, for example, the blocking area 604 may be an area other than the area where the two signal extraction sections 30A and 30B exist, in which fine raised areas are regularly or randomly arranged on the entire light receiving element 631. In addition, the regular arrangement may include, for example, a square arrangement and a hexagonal dense arrangement, etc. In addition, the random arrangement may include two or more distances between the raised areas.

[0311] 6.5 Function and Effect

[0312] As described above, by setting blocking areas 601 to 604 on the entire light receiving element 631, the movement of charges can be suppressed in the area near the surface of the semiconductor substrate 40 where a strong electric field is formed and photoelectric conversion is easily generated, thereby suppressing the generation of excessive current and reducing the increase in power consumption.

[0313] In addition, in the above-mentioned first to fourth examples, since a material that reflects the incident light L10 (for example, a reflective material or a high refractive index material) is used in the blocking area 601, 602, 603 or 604 located between the two signal extraction units 30A and 30B, the incident light L10 reflected from the blocking area 601, 602, 603 or 604 can also become the object of photoelectric conversion, thereby improving the quantum efficiency of the light receiving element 631.

[0314] Since other structures, functions and effects are the same as those in the above-mentioned embodiment, their detailed description is omitted.

[0315] 7. Seventh Implementation Plan

[0316] In addition, in the above embodiment, if Fig.41 As shown, for example, by providing a conical or quadrangular pyramid-shaped groove 701 in the light incident surface of the semiconductor substrate 40 , the light incident surface of the semiconductor substrate 40 can be formed into a moth-eye structure.

[0317] By forming the light incident surface of the semiconductor substrate 40 into a moth-eye structure in this way, the reflectivity on the light incident surface can be reduced, so that a large amount of light can be incident on the light receiving element 731, thereby improving the substantial quantum efficiency and improving the contrast between pixels.

[0318] On the other hand, the shape of the groove 701 is not limited to the conical shape and the quadrangular pyramid shape, and the groove 701 may also have various deformed shapes such as an elliptical cone and a polygonal pyramid (for example, a triangular pyramid).

[0319] Since other structures, functions and effects are the same as those in the above-mentioned embodiment, their detailed description is omitted.

[0320] 8. Application examples

[0321] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any type of mobile body including automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, robots, construction machinery, or agricultural machinery (tractors).

[0322] Fig.42 7000 is a block diagram showing a schematic configuration example of a vehicle control system 7000 as an example of a mobile control system to which the technology of the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. Fig.42 In the example shown, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an external information detection unit 7400, an internal information detection unit 7500, and an integrated control unit 7600. For example, the communication network 7010 connecting these multiple control units may be an in-vehicle communication network based on any standard such as a controller local network (CAN), a local interconnect network (LIN), a local area network (LAN), or FlexRay (registered trademark).

[0323] Each control unit includes: a microcomputer that performs arithmetic operation processing according to various programs; a storage unit that stores programs executed by the microcomputer, parameters for various arithmetic operations, etc.; and a drive circuit that drives various devices as control targets. Each control unit includes a network I / F that performs communication with other control units via the communication network 7010, and each control unit includes a communication I / F that performs communication with devices, sensors, etc. inside / outside the vehicle through wired communication or wireless communication. Fig.42 A microcomputer 7610, a general communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving section 7650, an in-vehicle device I / F 7660, a sound and image output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690 are shown as functional components of the integrated control unit 7600. Similarly, other control units also include a microcomputer, a communication I / F, a storage unit, and the like.

[0324] The drive system control unit 7100 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 7100 is used as a control device for the following devices: a drive force generating device (such as an internal combustion engine or a drive motor, etc.) for generating the drive force of the vehicle, 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 the braking force of the vehicle. The drive system control unit 7100 may have a function as a control device such as an anti-lock brake system (ABS: Antilock Brake System) or an electronic stability control (ESC: Electronic Stability Control).

[0325] The vehicle state detection unit 7110 is connected to the drive system control unit 7100. For example, the vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, and a sensor that detects the operation amount of the accelerator pedal, the operation amount of the brake pedal, the steering angle of the steering wheel, the engine speed, the rotation speed of the wheel, etc. The drive system control unit 7100 performs arithmetic operation processing using the signal input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric steering device, the brake device, etc.

[0326] 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 is used as a control device for a keyless entry system, a smart key system, a power window device, or various types of lights such as headlights, taillights, brake lights, turn signals, or fog lights. In this case, radio waves emitted from a portable device or signals of various switches instead of keys may be input to the body system control unit 7200. The body system control unit 7200 receives the input of the radio waves or signals and controls the door lock device, power window device, lights, etc. of the vehicle.

[0327] The battery control unit 7300 controls the secondary battery 7310 as a power source for driving the motor according to various programs. For example, information such as battery temperature, battery output voltage, or remaining battery capacity is input from a battery device including the secondary battery 7310 to the battery control unit 7300. The battery control unit 7300 performs arithmetic operation processing using these signals, and controls temperature adjustment of the secondary battery 7310 and a cooling device included in the battery device, etc.

[0328] The vehicle exterior information detection unit 7400 detects information related to the exterior of the vehicle on which the vehicle control system 7000 is installed. For example, at least one of the imaging unit 7410 and the vehicle exterior information detection unit 7420 is connected to the vehicle exterior information detection unit 7400. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. For example, the vehicle exterior information detection unit 7420 includes at least one of an environmental sensor for detecting current weather or weather conditions and a peripheral information detection sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle on which the vehicle control system 7000 is installed.

[0329] For example, the environmental sensor may be at least one of a raindrop sensor for detecting rainy days, a fog sensor for detecting fog, a sunshine sensor for detecting sunshine levels, and a snow sensor for detecting snowfall. The peripheral information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a light detection and ranging, laser imaging detection and ranging (LIDAR) device. The imaging 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.

[0330] here, Fig.43 An example of the installation position of the imaging unit 7410 and the vehicle exterior information detection unit 7420 is shown. For example, the imaging units 7910, 7912, 7914, 7916, and 7918 are respectively arranged at at least one position of the front nose, side mirrors, rear bumper, rear door, and upper part of the windshield in the vehicle compartment of the vehicle 7900. The imaging unit 7910 arranged at the front nose and the imaging unit 7918 arranged at the upper part of the windshield in the vehicle compartment mainly acquire images of the area in front of the vehicle 7900. The imaging units 7912 and 7914 included in the side mirrors mainly acquire images of the side of the vehicle 7900. The imaging unit 7916 included in the rear bumper or the rear door mainly acquires images of the rear area of ​​the vehicle 7900. The imaging unit 7918 arranged at the upper part of the windshield in the vehicle compartment is mainly used to detect the front vehicle, pedestrians, obstacles, traffic signals, traffic signs, lanes, etc.

[0331] also, Fig.43Examples of imaging ranges of imaging units 7910, 7912, 7914, and 7916 are shown. Imaging range a represents the imaging range of imaging unit 7910 disposed on the front nose. Imaging ranges b and c represent the imaging ranges of imaging units 7912 and 7914 disposed on the side mirrors, respectively. Imaging range d represents the imaging range of imaging unit 7916 disposed on the rear bumper or rear door. For example, a bird's-eye view image of vehicle 7900 seen from above can be acquired by superimposing image data captured by imaging units 7910, 7912, 7914, and 7916 on each other.

[0332] For example, the vehicle exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 disposed at the front, rear, side, or corner of the vehicle 7900 and the upper portion of the windshield in the vehicle compartment may be ultrasonic sensors or radar devices. For example, the vehicle exterior information detection units 7920, 7926, and 7930 disposed on the front nose, rear bumper, and rear door of the vehicle 7900 and the upper portion of the windshield in the vehicle compartment may be LIDAR devices. These vehicle exterior information detection units 7920-7930 are mainly used to detect vehicles ahead, pedestrians, obstacles, and the like.

[0333] Return to reference Fig.42 , continue to explain. The vehicle exterior information detection unit 7400 enables the imaging unit 7410 to capture images of the outside of the vehicle and receive the captured image data. In addition, the vehicle exterior information detection unit 7400 receives detection information from the vehicle exterior information detection unit 7420 connected thereto. 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, etc. and receives information about the received reflected waves. The vehicle exterior information detection unit 7400 can perform object detection processing or distance detection processing on people, vehicles, obstacles, traffic signs, characters on the road surface, etc. based on the received information. The vehicle exterior information detection unit 7400 can perform environment recognition processing based on the received information to identify rainfall, fog, road conditions, etc. The vehicle exterior information detection unit 7400 can calculate the distance to objects outside the vehicle based on the received information.

[0334] In addition, the vehicle exterior information detection unit 7400 can perform image recognition processing or distance detection processing for identifying people, vehicles, obstacles, traffic signs, characters on the road surface, etc. based on the received image data. The vehicle exterior information detection unit 7400 can perform processing such as distortion correction or alignment on the received image data, and synthesize the image data captured by different imaging units 7410 to generate a bird's-eye view image or a panoramic image. The vehicle exterior information detection unit 7400 can use the image data captured by different imaging units 7410 to perform viewpoint conversion processing.

[0335] The in-vehicle information detection unit 7500 detects in-vehicle information. For example, the in-vehicle information detection unit 7500 is connected to a driver state detection unit 7510 that detects the state of the driver. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's biometric information, a microphone that collects sounds inside the vehicle, and the like. For example, the biosensor is provided on a seat surface, a steering wheel, and the like, and detects biometric information of a passenger sitting on a seat or a driver gripping the steering wheel. Based on the detection information input from the driver state detection unit 7510, the in-vehicle information detection unit 7500 may calculate the driver's fatigue or concentration, or may determine whether the driver has fallen asleep. The in-vehicle information detection unit 7500 may perform processing such as noise elimination processing on the collected sound signal.

[0336] The integrated control unit 7600 controls the overall operation in the vehicle control system 7000 according to various programs. The input unit 7800 is connected to the integrated control unit 7600. For example, the input unit 7800 is implemented by a device such as a touch panel, a button, a microphone, a switch, a joystick, etc., through which a passenger can perform an input operation. Data obtained by recognizing a sound input via a microphone can be input to the integrated control unit 7600. For example, the input unit 7800 can be a remote control device using infrared or other radio waves, or can also be an external connection device such as a mobile phone or a personal digital assistant (PDA) that responds to the operation of the vehicle control system 7000. For example, the input unit 7800 can be a camera, and in this case, the passenger can input information through gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by a passenger can be input. In addition, for example, the input unit 7800 may include an input control circuit, etc., which generates an input signal based on information input by a passenger or the like using the input unit 7800, and outputs the input signal to the integrated control unit 7600. A passenger or the like inputs various types of data to the vehicle control system 7000 and instructs processing operations by operating the input unit 7800 .

[0337] The storage unit 7690 may include a read-only memory (ROM) storing various programs executed by the microcomputer, and a random access memory (RAM) storing various parameters, arithmetic operation results, sensor values, etc. In addition, the storage unit 7690 may also be implemented by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, etc.

[0338] The general communication I / F 7620 is a general communication I / F that coordinates communication with various devices existing in the external environment 7750. The general communication I / F 7620 may have a cellular communication protocol such as GSM (registered trademark) (Global System for Mobile Communications), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution) or LTE-A ((Long Term Evolution Advanced) LTE-Advanced), or other wireless communication protocols such as wireless LAN (also known as Wi-Fi (registered trademark)) and Bluetooth (registered trademark). For example, the general communication I / F 7620 may be connected to a device (e.g., an application server or a control server) existing on an external network (e.g., the Internet, a cloud network, or a network of a public communication operator, etc.) via a base station or an access point. In addition, for example, the general communication I / F 7620 may be connected to a terminal (e.g., a terminal of a driver, a pedestrian, or a store, or an MTC (Machine Type Communication) terminal, etc.) existing near the vehicle using a P2P (Peer to Peer) technology.

[0339] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol developed for vehicle use. For example, the dedicated communication I / F 7630 may have a standard protocol such as WAVE (Wireless Access in Vehicular Environment) which is a combination of the lower layer IEEE802.11p and the higher layer IEEE1609, DSRC (Dedicated Short Range Communication), or a cellular communication protocol. The dedicated communication I / F 7630 generally performs V2X communication, which is a concept including at least one of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0340] For example, the positioning unit 7640 performs positioning by receiving a GNSS signal from a GNSS (Global Navigation Satellite System) satellite (e.g., a GPS signal from a GPS (Global Positioning System) satellite) and generates position information including the latitude, longitude, and altitude of the vehicle. In addition, the positioning unit 7640 can identify the current position by exchanging signals with a wireless access point, or can obtain position information from a terminal such as a mobile phone, PHS, or smart phone with a positioning function.

[0341] For example, the beacon receiving unit 7650 receives radio waves or electromagnetic waves emitted from a wireless station installed on a road, etc., and acquires information such as the current position, traffic congestion, traffic closure, required time, etc. In addition, the function of the beacon receiving unit 7650 can be included in the above-mentioned dedicated communication I / F 7630.

[0342] The vehicle-mounted device I / F 7660 is a communication interface that coordinates the connection between the microcomputer 7610 and various vehicle-mounted devices 7760 present in the vehicle. The vehicle-mounted device I / F 7660 can 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 vehicle-mounted device I / F 7660 can establish a wired connection such as USB (universal serial bus), HDMI (registered trademark) (high-definition multimedia interface), or MHL (mobile high-definition link) through a connection terminal not shown (and a cable if necessary). For example, the vehicle-mounted device 7760 may include a mobile device or a wearable device carried by a passenger, and at least one of an information device carried in the vehicle or attached to the vehicle. In addition, the vehicle-mounted device 7760 may include a navigation device that searches for a route to an optional destination. The vehicle-mounted device I / F 7660 exchanges control signals or data signals with these vehicle-mounted devices 7760.

[0343] The in-vehicle network I / F 7680 is an interface that coordinates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals and the like according to a predetermined protocol supported by the communication network 7010.

[0344] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired through at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the vehicle-mounted device I / F 7660, and the vehicle-mounted network I / F 7680. For example, the microcomputer 7610 can calculate a control target value of a driving force generating device, a steering mechanism, or a braking device based on the acquired information related to the interior or exterior of the vehicle, and can output a control instruction to the drive system control unit 7100. For example, the microcomputer 7610 can perform cooperative control that is intended to realize functions of an ADAS (Advanced Driver Assistance System) including collision avoidance or collision mitigation of vehicles, following driving based on the distance between vehicles, vehicle speed maintenance driving, vehicle collision warning, lane departure warning of vehicles, and the like. In addition, the microcomputer 7610 can control the driving force generating device, steering mechanism, braking device, etc. based on the information obtained about the vicinity of the vehicle to perform cooperative control, which aims to achieve automatic driving in which the vehicle drives autonomously without relying on the driver's operation.

[0345] The microcomputer 7610 can generate three-dimensional distance information related to the distance between the vehicle and objects such as buildings or people around the vehicle based on information acquired through at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the vehicle-mounted device I / F 7660, and the vehicle-mounted network I / F 7680, and can generate local map information including surrounding information related to the current position of the vehicle. In addition, the microcomputer 7610 can predict the risk of vehicle collision, approaching pedestrians, etc., entering a closed road, etc. based on the acquired information, and can generate a signal for warning. For example, the signal for warning can be a signal to generate a warning sound or turn on a warning light.

[0346] The sound and image output unit 7670 transmits an output signal of at least one of sound and image to an output device capable of notifying information to a passenger of the vehicle or the outside of the vehicle in a visual or auditory manner. Fig.42 In the example of the vehicle, examples of the output device include an audio speaker 7710, a display unit 7720, and an instrument panel 7730. For example, the display unit 7720 may include at least one of an on-board display and a head-up display. The display unit 7720 may have an AR (augmented reality) display function. In addition to the above-mentioned devices, the output device may be other devices such as headphones, wearable devices such as glasses-type displays worn by passengers, projectors, lights, etc. When the output device is a display device, the display device visually displays the results obtained according to various types of processing performed by the microcomputer 7610 or information received from other control units in various formats such as text, images, tables, graphics, etc. In addition, when the output device is a sound output device, the sound output device converts an audio signal including reproduced sound data, acoustic data, etc. into an analog signal and outputs the analog signal in an auditory manner.

[0347] It should be pointed out that in Fig.42 In the example shown, at least two control units connected via the communication network 7010 can be integrated into one control unit. Alternatively, each individual control unit can be configured as a plurality of control units. In addition, the vehicle control system 7000 may include other control units not shown. In addition, in the above description, some or all of the functions of any control unit may be performed by other control units. That is, if the sending and receiving of information is performed via the communication network 7010, then a predetermined arithmetic operation process may be performed by any control unit. Similarly, a sensor or device connected to any control unit may be connected to other control units, and a plurality of control units may send and receive detection information to each other via the communication network 7010.

[0348] In addition, it is possible to implement the method for realizing the use of Figure 1 A computer program for each function of the ToF sensor 1 according to the present embodiment is described. In addition, a computer readable recording medium in which the computer program is stored can be provided. The recording medium may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or a flash memory. In addition, the above-mentioned computer program may be distributed, for example, via a network without using a recording medium.

[0349] In the vehicle control system 7000, it is possible to use Figure 1 The ToF sensor 1 according to the present embodiment is applied to Fig.42 The integrated control unit 7600 in the application example shown. For example, the control unit 11, the arithmetic operation unit 15, and the external I / F 19 of the ToF sensor 1 correspond to the microcomputer 7610, the storage unit 7690, and the vehicle network I / F 7680 of the integrated control unit 7600. However, the present disclosure is not limited thereto, and the vehicle control system 7000 may correspond to Figure 1 Host 80 in.

[0350] In addition, you can Fig.42 The module of the integrated control unit 7600 shown (for example, an integrated circuit module constructed using a single die) is implemented using Figure 1 At least some of the components of the ToF sensor 1 according to the present embodiment are described. Alternatively, Fig.42 The vehicle control system 7000 shown in FIG. 1 is implemented using a plurality of control units. Figure 1 The ToF sensor 1 according to the present embodiment is described.

[0351] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the essential features of the present disclosure. In addition, components in different embodiments and modifications can be appropriately combined.

[0352] In addition, the effects in the respective embodiments described in this specification are merely illustrative and not restrictive, and other effects may be obtained.

[0353] On the other hand, the present technology may also have the following configurations.

[0354] (1) A light receiving element comprising:

[0355] semiconductor substrate; and

[0356] a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form,

[0357] in,

[0358] Each of the pixel regions comprises:

[0359] A first semiconductor region provided on a first surface side of the semiconductor substrate;

[0360] a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region; and

[0361] A first barrier region is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate.

[0362] (2) The light receiving element according to (1), wherein a height of the first barrier region from the first surface is larger than a height of the first semiconductor region and the second semiconductor region from the first surface.

[0363] (3) The light receiving element according to (1) or (2), wherein a cross section of the first blocking region parallel to the first surface has a circular shape, an elliptical shape, or a polygonal shape.

[0364] (4) The light receiving element according to any one of (1) to (3), wherein the first blocking region has a columnar shape, a cone shape, or a truncated cone shape.

[0365] (5) The light receiving element according to any one of (1) to (4), wherein an upper portion of the first blocking region on the opposite side to the first surface has a curvature.

[0366] (6) The light receiving element according to any one of (1) to (5), wherein an upper portion of the first barrier region on the opposite side to the first surface is roughened.

[0367] (7) The light receiving element according to any one of (1) to (6), wherein a material of the first blocking region includes at least one of an insulating material, a material that reflects or absorbs light having a specific wavelength, and a high refractive index material.

[0368] (8) The light receiving element according to any one of (1) to (7) further includes one or more second blocking regions, wherein the one or more second blocking regions are arranged on the first surface side in the semiconductor substrate in a region other than a region between the first semiconductor region and the second semiconductor region.

[0369] (9) The light receiving element according to (8), wherein the first barrier region and the second barrier region are regions including a plurality of rows extending in a row direction or regions including a plurality of columns extending in a column direction.

[0370] (10) The light receiving element according to (8), wherein the first barrier region and the second barrier region are regions in which a plurality of convex regions are regularly or randomly arranged.

[0371] (11) The light receiving element according to any one of (8) to (10), wherein a material of the first blocking region is a reflective material or a high refractive index material.

[0372] (12) The light receiving element according to any one of (8) to (11), wherein a material of the second blocking region includes at least one of an insulating material, a material that reflects or absorbs light having a specific wavelength, and a high refractive index material.

[0373] (13) A light receiving element according to any one of (1) to (12), wherein the pixel separation portion protrudes from a second surface of the semiconductor substrate opposite to the first surface toward the first surface, or protrudes from the first surface of the semiconductor substrate toward the second surface.

[0374] (14) The light receiving element according to any one of (1) to (12), wherein the pixel separation portion penetrates from the first surface of the semiconductor substrate to a second surface opposite to the first surface.

[0375] (15) A light receiving element according to any one of (1) to (14), wherein the first semiconductor region and the second semiconductor region each include: a third semiconductor region located at a boundary between the pixel regions; and two fourth semiconductor regions adjacent to the third semiconductor region in such a manner that the boundary is interposed between the two fourth semiconductor regions, and

[0376] The third semiconductor region is shared by two of the pixel regions forming the boundary.

[0377] (16) The light receiving element according to (15), wherein the pixel separation section is cut off at a portion intersecting the first semiconductor region and the second semiconductor region.

[0378] (17) A light receiving element according to any one of (1) to (14), wherein the first semiconductor region and the second semiconductor region each include: a third semiconductor region located at a portion where corners of the four pixel regions are concentrated; and a fourth semiconductor region located in two regions, respectively, the two regions having a boundary formed by two adjacent pixel regions in the four pixel regions and the boundary being between the two regions, and

[0379] The third semiconductor region is shared by the two pixel regions.

[0380] (18) The light receiving element according to (17), wherein the pixel separation section is cut off at the portion where the corners of the four pixel regions are concentrated.

[0381] (19) A solid-state imaging device comprising:

[0382] semiconductor substrate; and

[0383] a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form,

[0384] in,

[0385] Each of the pixel regions comprises:

[0386] A first semiconductor region provided on a first surface side of the semiconductor substrate;

[0387] a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region; and

[0388] a first barrier region which is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate, and

[0389] Wherein, the solid-state imaging device further comprises:

[0390] a first readout circuit connected to the first semiconductor region; and

[0391] A second readout circuit is connected to the second semiconductor region.

[0392] (20) A distance measuring device comprising:

[0393] a light emitting unit that emits light having a predetermined wavelength;

[0394] a solid-state imaging device that generates a pixel signal from the received light; and

[0395] an arithmetic operation unit that calculates a distance to an object based on a pixel signal generated by the solid-state imaging device,

[0396] in,

[0397] The solid-state imaging device comprises:

[0398] semiconductor substrate; and

[0399] a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form,

[0400] in,

[0401] Each of the pixel regions comprises:

[0402] A first semiconductor region provided on a first surface side of the semiconductor substrate;

[0403] a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region; and

[0404] a first barrier region which is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate, and

[0405] Wherein, the solid-state imaging device further comprises:

[0406] a first readout circuit connected to the first semiconductor region; and

[0407] A second readout circuit is connected to the second semiconductor region.

[0408] [reference numerals list]

[0409] 1 ToF sensor

[0410] 11 Control Unit

[0411] 13 Lighting Unit

[0412] 14 Light receiving unit

[0413] 15 Arithmetic unit

[0414] 19 External I / F

[0415] 20 unit pixels

[0416] 20A, 20B Readout circuit

[0417] 21 p+ semiconductor region (MIX)

[0418] 22,22A,22B n+ semiconductor region (DET)

[0419] 23 Reset transistor

[0420] 24 Pass transistor

[0421] 26 FD

[0422] 27 Amplifier transistor

[0423] 28 Select transistor

[0424] 29A, 29B Constant current circuit

[0425] 30A, 30B Signal extraction unit

[0426] 31,231,331,431,531,631,731 Light receiving element

[0427] 40 Semiconductor substrate

[0428] 41 Insulation layer

[0429] 42 Anti-reflective film

[0430] 43 Flattening film

[0431] 44 shading film

[0432] 45 On-chip lens

[0433] 46,46a,46b,246,246a,246b,346,346a,446,446a Pixel separation unit

[0434] 50 stacked chips

[0435] 51 Optical receiving chip

[0436] 52 Circuit Chip

[0437] 80 Host

[0438] 90 Objects

[0439] 100 Solid-state imaging device

[0440] 101 pixel array unit

[0441] 102 System control unit

[0442] 103 Vertical drive circuit

[0443] 104 Column Processing Circuit

[0444] 105 Horizontal drive circuit

[0445] 106 Signal Processing Unit

[0446] 107 Data storage unit

[0447] 230,330,430 PN semiconductor area

[0448] 501,502,503,504,505,506,601,602,603,604 Blocked Area

[0449] 701 Groove

[0450] BH,BV Boundary

[0451] L1 Laser

[0452] L2, L11 reflected light

[0453] L10 Incident light

[0454] LD pixel drive line

[0455] VSL, VSL0, VSL1 vertical signal line

Claims

1. A light receiving element, comprising: Semiconductor substrates; and a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form, in, Each of the pixel regions comprises: a first semiconductor region provided on a first surface side in the semiconductor substrate and defining a first signal extraction portion; a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region and defining a second signal extraction section; a first barrier region which is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate; and One or more second barrier regions are provided on the first surface side in the semiconductor substrate in a region other than a region between the first semiconductor region and the second semiconductor region and the first signal extracting portion and the second signal extracting portion.

2. The light receiving element according to claim 1, wherein A height of the first barrier region from the first surface is greater than a height of the first semiconductor region and the second semiconductor region from the first surface.

3. The light receiving element according to claim 1 or 2, wherein: A cross section of the first barrier region parallel to the first surface has a circular shape, an elliptical shape, or a polygonal shape.

4. The light receiving element according to claim 1 or 2, wherein The first blocking area has a cylindrical shape, a cone shape, or a truncated cone shape.

5. The light receiving element according to claim 1 or 2, wherein The first barrier region has a curvature at an upper portion on an opposite side of the first surface.

6. The light receiving element according to claim 1 or 2, wherein: An upper portion of the first barrier region on the opposite side to the first surface is rough.

7. The light receiving element according to claim 1 or 2, wherein: The material of the first blocking region includes at least one of an insulating material, a material that reflects or absorbs light having a specific wavelength, and a high refractive index material.

8. The light receiving element according to claim 1, wherein The first barrier region and the second barrier region are regions including a plurality of rows extending in a row direction or regions including a plurality of columns extending in a column direction.

9. The light receiving element according to claim 1, wherein The first barrier region and the second barrier region are regions in which a plurality of convex regions are regularly or randomly arranged.

10. The light receiving element according to claim 1, wherein The material of the first blocking area is a reflective material or a high refractive index material.

11. The light receiving element according to claim 1, wherein The material of the second blocking region includes at least one of an insulating material, a material that reflects or absorbs light having a specific wavelength, and a high refractive index material.

12. The light receiving element according to claim 1 or 2, wherein: The pixel separation portion protrudes from a second surface of the semiconductor substrate opposite to the first surface toward the first surface, or protrudes from the first surface of the semiconductor substrate toward the second surface.

13. The light receiving element according to claim 1 or 2, wherein: The pixel separation portion extends from the first surface of the semiconductor substrate to a second surface opposite to the first surface.

14. The light receiving element according to claim 1 or 2, wherein The first semiconductor region and the second semiconductor region each include: a third semiconductor region located at a boundary between the pixel regions; and two fourth semiconductor regions adjacent to the third semiconductor region in such a manner that the boundary is interposed between the two fourth semiconductor regions, and The third semiconductor region is shared by two of the pixel regions forming the boundary.

15. The light receiving element according to claim 14, wherein The pixel separation section is cut at a portion intersecting the first semiconductor region and the second semiconductor region.

16. The light receiving element according to claim 1 or 2, wherein: The first semiconductor region and the second semiconductor region each include: a third semiconductor region located at a portion where corners of the four pixel regions are concentrated; and a fourth semiconductor region located in two regions, respectively, the two regions having a boundary formed by two adjacent pixel regions in the four pixel regions and the boundary being between the two regions, and The third semiconductor region is shared by the two pixel regions.

17. The light receiving element according to claim 16, wherein The pixel separation section is cut off at the portion where the corners of the four pixel regions are concentrated.

18. A solid-state imaging device comprising: Semiconductor substrates; and a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form, in, Each of the pixel regions comprises: a first semiconductor region provided on a first surface side in the semiconductor substrate and defining a first signal extraction portion; a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region and defining a second signal extraction section; a first barrier region which is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate; and one or more second blocking regions, the one or more second blocking regions being provided on the first surface side in the semiconductor substrate in a region other than a region between the first semiconductor region and the second semiconductor region and the first signal extraction section and the second signal extraction section, and Wherein, the solid-state imaging device further comprises: a first readout circuit connected to the first semiconductor region; and A second readout circuit is connected to the second semiconductor region.

19. A distance measuring device, comprising: a light emitting unit that emits light having a predetermined wavelength; a solid-state imaging device that generates a pixel signal from the received light; and an arithmetic operation unit that calculates a distance to an object based on a pixel signal generated by the solid-state imaging device, in, The solid-state imaging device comprises: semiconductor substrate; and a lattice-shaped pixel separation portion, which divides the semiconductor substrate into a plurality of pixel regions arranged in a matrix form, in, Each of the pixel regions comprises: a first semiconductor region provided on a first surface side in the semiconductor substrate and defining a first signal extraction portion; a second semiconductor region provided on the first surface side in the semiconductor substrate separately from the first semiconductor region and defining a second signal extraction section; a first barrier region which is provided between the first semiconductor region and the second semiconductor region on the first surface side in the semiconductor substrate and has a dielectric constant different from that of the semiconductor substrate; and one or more second blocking regions, the one or more second blocking regions being provided on the first surface side in the semiconductor substrate in a region other than a region between the first semiconductor region and the second semiconductor region and the first signal extraction section and the second signal extraction section, and Wherein, the solid-state imaging device further comprises: a first readout circuit connected to the first semiconductor region; and A second readout circuit is connected to the second semiconductor region.

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