Solid-state imaging device and electronic apparatus

Abstract

A solid-state imaging device of the present disclosure includes a transfer transistor having a vertical gate electrode, and a component separation portion at least a part of which is disposed apart from the vertical gate electrode with a semiconductor layer interposed therebetween, the semiconductor layer having a high impurity concentration of a first conductivity type, and the component separation portion being composed of an oxide film insulator.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a solid-state imaging device and an electronic apparatus. BACKGROUND

[0002] For example, a solid-state imaging device has been used for an imaging device such as a digital camera or a video camera or an electronic apparatus such as a portable terminal apparatus having an imaging function. As a solid-state imaging device, a CMOS (Complementary Metal Oxide Semiconductor) image sensor is known, which reads out a charge accumulated in a photodiode as a photoelectric conversion element via a MOS transistor (for example, see Patent Documents 1 to 3).

[0003] LIST OF CITATIONS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: International Publication No. WO 2018 / 221261

[0006] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2010-283086

[0007] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2018-148116 SUMMARY

[0008] Incidentally, a solid-state imaging device is required to suppress dark current and improve transfer characteristics. Therefore, it is desirable to provide a solid-state imaging device capable of achieving dark current suppression and transfer characteristics improvement and an electronic apparatus including the same.

[0009] A solid-state imaging device according to an embodiment of the present disclosure includes a semiconductor substrate including a light-receiving surface and a plurality of pixels disposed opposite the light-receiving surface. Each of the pixels includes a photoelectric conversion section, a charge holding section, a transfer transistor, a device separation section, and a semiconductor layer. The photoelectric conversion section performs photoelectric conversion on light incident via the light-receiving surface. The charge holding section is formed as a semiconductor region of a second conductive type different from a first conductive type within a semiconductor region of the first conductive type in the semiconductor substrate, and holds charges transferred from the photoelectric conversion section. The transfer transistor includes a vertical gate electrode reaching the photoelectric conversion section and a gate insulating film in contact with the vertical gate electrode, the gate insulating film being formed on a surface of the semiconductor substrate opposite the light-receiving surface, the transfer transistor transferring charges from the photoelectric conversion section to the charge holding section. The device separation section is formed close to the surface of the semiconductor substrate opposite the light-receiving surface, and contains an oxide film insulator. The semiconductor layer is in contact with side and bottom surfaces of the device separation section and the gate insulating film, and has a first conductive type impurity concentration higher than that of the semiconductor region of the first conductive type. At least a portion of the device separation section is disposed apart from the vertical gate electrode with a portion of the semiconductor layer in contact with the gate insulating film interposed therebetween.

[0010] An electronic device according to an embodiment of the present disclosure includes a solid-state imaging device and a signal processing circuit. The solid-state imaging device outputs a pixel signal corresponding to incident light. The signal processing circuit processes the pixel signal. The solid-state imaging device provided in the electronic device has the same configuration as that of the above-described solid-state imaging device.

[0011] The solid-state imaging device and the electronic device according to respective embodiments of the present disclosure each are provided with a transfer transistor including a vertical gate electrode, and has at least a portion of a device separation section disposed apart from the vertical gate electrode with a semiconductor layer interposed therebetween. The device separation section contains an oxide film insulator. The semiconductor layer has a high first conductive type impurity concentration. Even in a case where the device separation section is disposed closer to the vertical gate electrode, this makes it possible to improve transfer characteristics while suppressing dark current. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a diagram showing an example of a schematic configuration of a solid-state imaging device according to an embodiment of the present disclosure.

[0013] Figure 2 FIG. 2 is a diagram showing an example of a circuit configuration of a sensor pixel in Figure 1 FIG. 3 is a diagram showing an example of a circuit configuration of a sensor pixel in

[0014] Figure 3 FIG. 4 is a diagram showing an example of a circuit configuration of a sensor pixel in Figure 1An example diagram showing the planar composition of sensor pixels.

[0015] Figure 4 It shows along Figure 3 The diagram shows an example of a sensor pixel cross-section formed by the line AA in the figure.

[0016] Figure 5 It shows along Figure 3 The diagram shows an example of a sensor pixel cross-section formed by the line BB in the figure.

[0017] Figure 6 It is shown Figure 4 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0018] Figure 7 It is shown Figure 5 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0019] Figure 8 It is a diagram. Figure 4 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0020] Figure 9 It is a diagram. Figure 5 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0021] Figure 10 It is a diagram. Figure 4 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0022] Figure 11 It is shown Figure 5 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0023] Figure 12 It is shown Figure 5 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0024] Figure 13 It is shown Figure 2 A diagram showing a modified example of the circuitry configuration of the sensor pixels.

[0025] Figure 14 It is shown Figure 4 A diagram showing a deformed example formed by the cross-section of the sensor pixels.

[0026] Figure 15 This is a diagram illustrating an example of a schematic configuration of an imaging system having an imaging apparatus according to the above-described embodiments and their variations.

[0027] Figure 16 It is shown Figure 15 A diagram illustrating an example of the imaging process of an imaging system.

[0028] Figure 17 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0029] Figure 18 is a diagram that assists in explaining an example of a setting position of an outside-vehicle information detection unit and an imaging unit.

[0030] Figure 19 is a diagram showing an example of a schematic configuration of an endoscope surgery system.

[0031] Figure 20 is a block diagram showing an example of a functional configuration of a camera and a camera control unit (CCU). DETAILED DESCRIPTION

[0032] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, constituent elements having substantially the same function are denoted with the same reference numerals, and therefore repeated explanation thereof is omitted.

[0033] Further, in this specification and the drawings, a plurality of constituent elements having substantially the same or similar function are distinguished, in some cases, by adding different numerals at the end of the same reference numerals. However, in the case where it is not necessary to particularly distinguish a plurality of constituent elements having substantially the same or similar function, only the same reference numerals are assigned to them. Further, in some cases, similar constituent elements according to different embodiments are distinguished by adding different letters to the same reference numerals. However, in the case where it is not necessary to particularly distinguish similar constituent elements, only the same reference numerals are added.

[0034] In addition, the drawings referred to in the following explanation are for explaining the embodiments of the present disclosure and facilitating the understanding of the present disclosure, and in some cases, the shapes, sizes, ratios, and the like shown in the drawings are different from the actual ones for the sake of easy understanding. Further, the design of the solid-state imaging element shown in the drawings can be appropriately changed by taking the following explanation and known technology into consideration. In addition, in the explanation using the cross-sectional view of the solid-state imaging element, the up-down direction of the stacked structure of the solid-state imaging element corresponds to the relative direction in the case where the top surface is used as the incident surface of the light incident to the solid-state imaging element. In some cases, the up-down direction is different from the up-down direction following the actual gravitational acceleration.

[0035] In addition, in the following explanation, the expression regarding the size and the shape not only refers to the value identical to the one defined mathematically and the shape defined geometrically, but also includes the shape having an industrially acceptable difference in the step of manufacturing the solid-state imaging element, even the shape similar to the shape.

[0036] Further, in the following description of the circuit configuration, unless otherwise specified, "connection" refers to electrical connection between a plurality of elements. Further, "connection" in the following description includes not only direct electrical connection of a plurality of elements, but also indirect electrical connection of a plurality of elements via other elements.

[0037] Note that the description is made in the following order.

[0038] 1. Embodiment (Solid-state imaging device) Figures 1-5

[0039] 2. Modification (Solid-state imaging device) Figures 6-14

[0040] 3. Application Example (Imaging system) Figure 15 and Figure 16

[0041] 4. Application Example

[0042] Application Example of Mobile Body Figure 17 and Figure 18

[0043] Application Example of Endoscope Surgical System Figure 19 and Figure 20

[0044] <1. Embodiment>

[0045] [Configuration]

[0046] Figure 1 An example of a schematic configuration of a solid-state imaging device 1 according to the embodiment of the present disclosure is shown. The solid-state imaging device 1 includes a pixel array section 10 in which a plurality of pixels 11 are arranged in a matrix. The pixel array section 10 has a configuration in which a plurality of pixels 11 are layered on a semiconductor substrate 12 containing, for example, silicon. The plurality of sensor pixels 11 are arranged in a matrix at positions opposite to a light-receiving surface 11A that is a back surface of the semiconductor substrate 12. In other words, the pixel array section 10 includes the semiconductor substrate 12 having the light-receiving surface 11A and a plurality of sensor pixels 11 arranged opposite to the light-receiving surface 11A.

[0047] The pixel array section 10 further includes a plurality of pixel drive lines and a plurality of vertical signal lines VSL on a semiconductor substrate 12 containing, for example, silicon. Each pixel drive line is a wiring to which a control signal for controlling the output of the electric charge accumulated in the sensor pixels 11 is applied. The pixel drive lines extend, for example, in the row direction. Each vertical signal line VSL is a wiring to output the pixel signal output from each sensor pixel 11 to the logic circuit 20. The vertical signal lines VSL extend, for example, in the column direction. The logic circuit 20 is provided, for example, on the semiconductor substrate 12 and around the pixel array section 10. The logic circuit 20 can be provided on a semiconductor substrate or a semiconductor layer formed on the semiconductor substrate 12. The logic circuit 20 includes, for example, a vertical drive circuit 21, a column signal processing circuit 22, a horizontal drive circuit 23, a system control circuit 24, an output circuit 25, and the like. Each block of the solid-state imaging device 1 according to the present embodiment will be described in detail below.

[0048] (Vertical drive circuit 21)

[0049] The vertical drive circuit 21 includes, for example, a shift register. The vertical drive circuit 21 selects the pixel drive line 42, supplies a pulse for driving the sensor pixels 11 to the selected pixel drive line 42, and drives the sensor pixels 11 in predetermined unit pixel rows. The vertical drive circuit 21 sequentially and selectively scans each sensor pixel 11 in the pixel array section 10 in predetermined unit pixel rows in the vertical direction (upward and downward direction) in the pixel array section 10. Figure 1

[0050] (Column signal processing circuit 22)

[0051] The column signal processing circuit 22 is provided for each column of the sensor pixels 11 and performs signal processing such as noise removal for each pixel column on the pixel signal output from the sensor pixels 11 of the predetermined unit pixel row. The column signal processing circuit 22 performs, for example, Correlated Double Sampling (CDS) processing to remove pixel-inherent fixed pattern noise. The column signal processing circuit 22 includes, for example, a single slope A / D converter. The single slope A / D converter includes, for example, a comparator and a counter circuit and performs AD (Analog-Digital) conversion on the pixel signal.

[0052] (Horizontal drive circuit 23)

[0053] ​The horizontal drive circuit 23 includes, for example, a shift register. The horizontal drive circuit 23 sequentially outputs horizontal scanning pulses to sequentially select the respective column signal processing circuits 22 and output the pixel signals from the respective column signal processing circuits 22 to the horizontal signal line.

[0054] (Output circuit 25)

[0055] The output circuit 25 performs signal processing on the pixel signals sequentially supplied from the respective column signal processing circuits 22 via the horizontal signal line and outputs the resulting pixel signals. The output circuit 25 can function as a functional section that performs buffering, for example, and can perform processing such as black level adjustment, column bias correction, various kinds of digital signal processing, and the like. Buffering refers to temporary storage of pixel signals to compensate for a difference in processing speed and transmission speed when exchanging pixel signals.

[0056] (System control circuit 24)

[0057] The system control circuit 24 receives an input clock and data for issuing instructions regarding an operation mode and the like. In addition, the system control circuit 24 outputs data such as internal information of the sensor pixels 11. Based on a vertical synchronization signal, a horizontal synchronization signal, and a main clock, the system control circuit 24 generates a clock signal and a control signal that serve as a basis for operations of the vertical drive circuit 21, the column signal processing circuit 22, the horizontal drive circuit 23, and the like. The system control circuit 24 outputs the generated clock signal and the generated control signal to the vertical drive circuit 21, the column signal processing circuit 22, the horizontal drive circuit 23, and the like.

[0058] The planar configuration example of the solid-state imaging device 1 according to the present embodiment is not limited to the example shown in Figure 1 but can include, for example, other circuits and the like.

[0059] (Sensor pixel 11)

[0060] Next, the circuit configuration of the sensor pixel 11 will be described. Figure 2An example of the circuit configuration of the sensor pixel 11 is shown. As described above, the pixel array section 10 includes a plurality of sensor pixels 11. Each sensor pixel 11 includes, for example, a photodiode PD and a pixel circuit. The photodiode PD performs photoelectric conversion on light incident via the light-receiving surface 11A. The photodiode PD corresponds to a specific example of the "photoelectric conversion section" according to the present disclosure. The pixel circuit generates a pixel signal based on, for example, the charge output from the photodiode PD, and outputs the pixel signal to the vertical signal line VSL. The pixel circuit includes a plurality of pixel transistors. The pixel circuit includes, for example, a transfer transistor TRX, a selection transistor SEL, a reset transistor RST, an amplification transistor AMP, and the like. The pixel transistor is, for example, a MOS (Metal Oxide Semiconductor) transistor. The pixel circuit also includes a floating diffusion section FD. The transfer transistor TRX corresponds to a specific example of the "transfer transistor" according to the present disclosure. The floating diffusion section FD corresponds to a specific example of the "charge holding section" according to the present disclosure.

[0061] The transfer transistor TRX is connected between the photodiode PD and the floating diffusion section FD, and transfers the charge accumulated in the photodiode PD from the photodiode PD to the floating diffusion section FD according to a control signal applied to the gate electrode. The transfer transistor TRX transfers the charge from the photodiode PD to the floating diffusion section FD. The drain of the transfer transistor TRX is electrically connected to the floating diffusion section FD, and the gate of the transfer transistor TRX is connected to the pixel drive line.

[0062] The floating diffusion section FD is a floating diffusion region that temporarily holds the charge transferred from the photodiode PD via the transfer transistor TRX. For example, the reset transistor RST is connected to the floating diffusion section FD, and the vertical signal line VSL is also connected to the floating diffusion section FD via the amplification transistor AMP and the selection transistor SEL.

[0063] The reset transistor RST has a drain connected to the power supply line VDD and has a source connected to the floating diffusion section FD. The reset transistor RST initializes (resets) the floating diffusion section FD according to a control signal applied to the gate electrode. For example, in a case where the reset transistor RST is turned on, the potential of the floating diffusion section FD is reset to the potential level of the power supply line VDD. In other words, the floating diffusion section FD is initialized.

[0064] The amplification transistor AMP has a gate electrode connected to the floating diffusion section FD and has a drain connected to the power supply line VDD. The amplification transistor AMP functions as an input section of a source follower circuit that reads the charge obtained by the photoelectric conversion in the photodiode PD. In other words, the source of the amplification transistor AMP is connected to the vertical signal line VSL via the selection transistor SEL, thereby providing a source follower circuit and a constant current source connected to one end of the vertical signal line VSL.

[0065] The selection transistor SEL is connected between the source of the amplification transistor AMP and the vertical signal line VSL. The gate electrode of the selection transistor SEL is supplied with a control signal as a selection signal. In a case where the control signal is on, the selection transistor SEL enters an on state and the sensor pixel 11 connected to the selection transistor SEL enters a selected state. In a case where the sensor pixel 11 enters the selected state, the pixel signal output from the amplification transistor AMP is read out by the column signal processing circuit 22 via the vertical signal line VSL.

[0066] Next, the structure of the sensor pixel 11 will be described. Figure 3 An example of a planar configuration of the sensor pixel 11 is shown. Figure 4 An example of a cross-sectional configuration of the sensor pixel 11 taken along a line A-A in Figure 3 An example of a cross-sectional configuration of the sensor pixel 11 taken along a line B-B in Figure 5 An example of a cross-sectional configuration of the sensor pixel 11 taken along a line B-B in Figure 3 An example of a cross-sectional configuration of the sensor pixel 11 taken along a line B-B in

[0067] A pixel circuit including, for example, a transfer transistor TRX and the like is formed on the upper face of the semiconductor substrate 12. Therefore, the upper face of the semiconductor substrate 12 serves as a formation face 11B of the transfer transistor TRX and the like. Note that a part of the pixel circuit (for example, the selection transistor SEL, the amplification transistor, and the reset transistor RST) can be formed in a semiconductor substrate or a semiconductor layer formed on the side of the upper face (formation face 11B) of the semiconductor substrate 12. A wiring layer including, for example, a wiring and the like in the pixel circuit is formed in contact on the upper face (formation face 11B) of the semiconductor substrate 12.

[0068] The semiconductor substrate 12 includes, for example, a silicon substrate. The semiconductor substrate 12 has a semiconductor region (a well layer 14) of a first conductivity type (for example, P type) at a part of the upper face (formation face 11B) and in the vicinity thereof. The semiconductor substrate 12 has a semiconductor region of the first conductivity type (for example, P type) in a region deeper than the well layer 14, which has a lower impurity concentration than the well layer 14.

[0069] The semiconductor substrate 12 includes a semiconductor region 13 of a second conductivity type (e.g., N type) different from the first conductivity type (e.g., P type) in a semiconductor region of the first conductivity type (e.g., P type) having a lower impurity concentration than the well layer 14. A photodiode PD is formed by a PN junction of the semiconductor region 13 and a semiconductor region having the first conductivity type (e.g., P type) adjacent to the semiconductor region 13. The photodiode PD performs photoelectric conversion on light incident via the light-receiving surface 11A as a back surface of the semiconductor substrate 12. The photodiode PD performs photoelectric conversion to generate electric charges corresponding to the amount of received light. A cathode of the photodiode PD is electrically connected to a source of a transfer transistor TRX and an anode of the photodiode PD is electrically connected to a reference potential line (e.g., ground GND).

[0070] The semiconductor substrate 12 has an insulating film 15 on a part of the upper face (formation surface 11B). The insulating film 15 serves as a gate oxide film of the transfer transistor TRX. The insulating film 15 is, for example, a silicon oxide film formed by thermal oxidation or the like of the surface of the silicon substrate. The semiconductor substrate 12 has a semiconductor layer 17 in a layer between the well layer 14 and the insulating film 15 in the vicinity of the upper face (formation surface 11B). The semiconductor layer 17 has an impurity concentration of the first conductivity type (e.g., P type) higher than that of the well layer 14. The semiconductor layer 17 corresponds to a specific example of the “semiconductor layer” according to the present disclosure. The semiconductor layer 17 is formed in contact with the insulating film 15 and the well layer 14. The semiconductor layer 17 is also formed in contact with the side surface and the bottom surface of the element separation portion 16 described later.

[0071] The transfer transistor TRX includes a vertical gate electrode VG as a gate electrode. A part other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG is formed in the semiconductor substrate 12 to extend in the thickness direction of the semiconductor substrate 12. The lower end portion of the vertical gate electrode VG is formed, for example, to a depth sufficient to reach the photodiode PD. The upper end portion of the vertical gate electrode VG is formed in contact with the upper face of the semiconductor substrate 12. The vertical gate electrode VG is formed by, for example, filling a trench provided in the semiconductor substrate 12 with a metal material or a conductive material such as polysilicon, which is covered with the insulating film 15. The insulating film 15 in the trench is formed, for example, by thermal oxidation or the like of the inner wall of the trench provided in the semiconductor substrate 12. The conductive material is filled into the trench, for example, by CVD (chemical vapor deposition) or the like.

[0072] The transfer transistor TRX includes the insulating film 15 as a gate oxide film. The insulating film 15 corresponds to a specific example of the “gate oxide film” according to the present disclosure. The insulating film 15 is formed on the upper face (surface opposite to the light-receiving surface 11A (formation surface 11B)) of the semiconductor substrate 12. The insulating film 15 is formed in contact with a part other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG.

[0073] The floating diffusion portion FD is disposed separately from a portion other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG, for example. The floating diffusion portion FD can be disposed separately from the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. A semiconductor region of a second-conductivity-type (for example, N-type) having a lower impurity concentration than the floating diffusion portion FD can be provided around the floating diffusion portion FD. In this case, the semiconductor region can be disposed at a position at which at least a portion of the semiconductor region overlaps the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12.

[0074] Each sensor pixel 11 includes an element separation portion 16 on the upper surface (formation surface 11B) of the semiconductor substrate 12. The element separation portion 16 corresponds to a specific example of the "element separation portion" according to the present disclosure. The element separation portion 16 is formed in the vicinity of the surface (formation surface 11B) of the semiconductor substrate 12 on the opposite side from the light-receiving surface 11A. The element separation portion 16 electrically separates two sensor pixels 11 adjacent to each other in the vicinity of the upper surface (formation surface 11B) of the semiconductor substrate 12. The lower end of the element separation portion 16 is provided, for example, to be insufficient to reach the formation depth of the photodiode PD in the semiconductor substrate 12. At least a portion of the element separation portion 16 is disposed separately from a portion other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG with the semiconductor layer 17 interposed therebetween. At least a portion of the element separation portion 16 is disposed separately from a portion other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG with the portion of the contact insulating film 15 of the semiconductor layer 17 interposed therebetween.

[0075] The semiconductor layer 17 is formed in the vicinity of the upper surface (formation surface 11B) of the semiconductor substrate 12. The semiconductor layer 17 is formed in contact with the side surface and the bottom surface of the element separation portion 16. Further, the semiconductor layer 17 extends from the element separation portion 16 side toward the vertical gate electrode VG in the vicinity of the upper surface (formation surface 11B) of the semiconductor substrate 12. The semiconductor layer 17 is disposed at a position at which a portion of the semiconductor layer 17 overlaps the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12.

[0076] At least a portion of the element separation portion 16 can be disposed separately from the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. Any portion of the element separation portion 16 can be disposed separately from the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. The element separation portion 16 includes an oxide film insulator such as an STI (shallow trench isolation), for example. The STI is formed by filling a trench formed in the semiconductor substrate 12 with silicon oxide by CVD or the like, for example.

[0077] Each sensor pixel 11 can have a color filter and a light-receiving lens on the back surface (light-receiving surface 11A) side of the semiconductor substrate 12. In this case, the solid-state imaging device 1 includes a plurality of light-receiving lenses provided for each sensor pixel 11. The plurality of light-receiving lenses are provided for each photodiode PD. The plurality of light-receiving lenses are disposed at positions opposite the photodiode PD. Each light-receiving lens is provided, for example, in contact with the color filter and at a position opposite the photodiode PD with the color filter interposed therebetween.

[0078] Each sensor pixel 11 can include an element separation portion that electrically and optically separates two photodiodes PD adjacent to each other. In this case, the element separation portion is formed so as to extend in the normal direction (thickness direction) of the semiconductor substrate 12. For example, the element separation portion is formed so as to penetrate the semiconductor substrate 12. The element separation portion includes, for example, a DTI (deep trench isolation) structure. The DTI includes, for example, an insulating film in contact with an inner wall of a trench provided from the back surface (light-receiving surface 11A) side of the semiconductor substrate 12 and a metal buried portion provided inside the insulating film. The insulating film is, for example, an oxide film formed by heat oxidation of the semiconductor substrate 12 and contains, for example, silicon oxide. The metal buried portion is formed, for example, by heat treatment using a displacement phenomenon and is formed, for example, by using aluminum or an aluminum alloy.

[0079] [Effects]

[0080] Next, the effects of the solid-state imaging device 1 according to the present embodiment will be described.

[0081] In the present embodiment, a vertical transistor (transfer transistor TRX) including a vertical gate electrode VG is provided. At least a portion of the element separation portion 16 is disposed apart from a portion other than the upper end portion (umbrella-shaped portion) of the vertical gate electrode VG with the semiconductor layer 17 interposed therebetween. Even in a case where the element separation portion 16 is closer to the vertical gate electrode VG, for example, as shown in FIG. 9, it is possible to improve the transfer characteristics while suppressing the dark current. Figure 6 and Figure 7

[0082] In the present embodiment, the semiconductor layer 17 is provided between at least a portion of the element separation portion 16 and the vertical gate electrode VG. Further, any portion of the element separation portion 16 is disposed apart from the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. Compared to a case where the semiconductor layer 17 is not provided between the element separation portion 16 and the vertical gate electrode VG, it is possible to improve the transfer characteristics while suppressing the dark current.

[0083] [2. Modified Example]

[0084] A modified example of the solid-state imaging device 1 according to the above-described embodiment will be described below.

[0085] ​[Modified Example A]

[0086] In the above embodiment, a part of the semiconductor layer 17 overlaps the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. However, in the above embodiment, for example, as shown in Figure 8 and Figure 9 , the semiconductor layer 17 can be configured separately from the vertical gate electrode VG when viewed in the normal direction of the semiconductor substrate 12. Figure 8 A modified example of the cross-sectional configuration of the sensor pixel 11 taken along the line A-A in Figure 3 is shown. Figure 9 A modified example of the cross-sectional configuration of the sensor pixel 11 taken along the line B-B in Figure 3 is shown. Even in this case, the dark current can be suppressed and the transfer characteristics can be improved as in the above embodiment.

[0087] [Modified Example B]

[0088] In the above embodiment and the modified examples thereof, the photodiode PD is formed at a position deeper than the well layer 14 in the semiconductor substrate 12. However, in the above embodiment and the modified examples thereof, for example, as shown in Figure 10 and Figure 11 , a part of the photodiode PD can be formed in the charge transfer path in the transfer transistor TRX. Figure 10 A modified example of the cross-sectional configuration of the sensor pixel 11 taken along the line A-A in Figure 3 is shown. Figure 11 A modified example of the cross-sectional configuration of the sensor pixel 11 taken along the line B-B in Figure 3 is shown. In this case, a part of the photodiode PD extends toward the upper face (formation face 11B) of the semiconductor substrate 12 along the vertical gate electrode VG. In this case, improvement of the transfer characteristics can be achieved.

[0089] [Modified Example C]

[0090] In the above embodiment and the modified examples thereof, the upper end portion of the vertical gate electrode VG has an umbrella shape. However, in the above embodiment and the modified examples thereof, for example, as shown in Figure 12 , a part of the upper end portion of the vertical gate electrode VG corresponding to the part of the transfer gate electrode which is not the transfer path can be omitted. In this case, the dimension of the upper end portion of the vertical gate electrode VG in the in-plane direction of the stack is reduced by the omitted amount. In this case, the element separation portion 16 can be made closer to the vertical gate electrode VG by the amount by which the dimension of the upper end portion of the vertical gate electrode VG in the in-plane direction of the stack is reduced. As a result, the pixel size of the sensor pixel 11 can be reduced by the amount by which the dimension of the upper end portion of the vertical gate electrode VG in the in-plane direction of the stack is reduced.

[0091] [Modification D]

[0092] In the above implementation schemes and their variations, for example, such as Figure 13 As shown, each sensor pixel 11 may include a photodiode PD1 instead of a photodiode PD, and may also include a photodiode PD2 in addition to photodiode PD1. In this case, for example, as Figure 13 As shown, in addition to the transmission transistor TRX, reset transistor RST, select transistor SEL, amplification transistor AMP and floating diffusion section FD, each pixel circuit may also include a transmission transistor TGS, pixel capacitor FC, FC connection transistor FCC and conversion efficiency switching transistor EXC.

[0093] In this modified example, each pixel circuit generates a pixel signal based on the charge held in the floating diffuser FD and outputs it to the vertical signal line VSL. The photodiode PD2 performs photoelectric conversion on light incident via the light receiving surface 11A. The photodiode PD2 performs photoelectric conversion to generate a charge corresponding to the amount of received light. The cathode of the photodiode PD2 is electrically connected to the source of the transmission transistor TGS, and the anode of the photodiode PD2 is electrically connected to a reference potential line (e.g., ground GND).

[0094] In this variation, photodiode PD1 can generate more charge per unit illuminance per unit time compared to photodiode PD2. In this case, the sensitivity of photodiode PD1 is higher than that of photodiode PD2, while the sensitivity of photodiode PD2 is lower than that of photodiode PD1.

[0095] The transfer transistor TGS is connected between the photodiode PD2 and the node between the pixel capacitor FC and the FC connection transistor FCC. The transfer transistor TGS moves the charge accumulated in the photodiode PD2 to the node between the pixel capacitor FC and the FC connection transistor FCC according to a control signal applied to the gate electrode.

[0096] The reset transistor RST has a drain connected to the power supply line VDD1 and a source connected to the drain of the efficiency switching transistor EXC. The reset transistor RST initializes (resets) the floating diffuser FD via the efficiency switching transistor EXC according to a control signal applied to the gate electrode. For example, when both the reset transistor RST and the efficiency switching transistor EXC are turned on, the potential of the floating diffuser FD is reset to the potential level of the power supply line VDD1. In other words, the floating diffuser FD is initialized.

[0097] The gate electrode of the amplifying transistor AMP is connected to the floating diffuser FD, the drain is connected to the power supply line VDD1, and the source is connected to the select transistor SEL. The amplifying transistor AMP serves as the input of a source follower circuit that reads out the charge held in the floating diffuser FD. In other words, the source of the amplifying transistor AMP is connected to the vertical signal line VSL via the select transistor SEL, thereby providing a source follower circuit and a constant current source connected to one end of the vertical signal line VSL.

[0098] The intra-pixel capacitor FC is connected between the node between the FC connection transistor FCC and the transfer transistor TGS and the power line VDD2. The intra-pixel capacitor FC accumulates the charge transferred (overflowed) from the photodiode PD2.

[0099] The FC connection transistor FCC is connected to the node between the transmission transistor TGS and the intra-pixel capacitor FC, and to the node between the reset transistor RST and the conversion efficiency switching transistor EXC. The FC connection transistor FCC combines the capacitance potential of the floating diffuser FD and the capacitance potential of the intra-pixel capacitor FC according to the control signal applied to the gate electrode.

[0100] The efficiency switching transistor EXC is connected between the node between the reset transistor RST and the FC connection transistor FCC and the floating diffuser FD. The efficiency switching transistor EXC combines the capacitance potential of the pixel capacitor FC and the capacitance potential of the floating diffuser FD according to the control signal applied to the gate electrode.

[0101] For example, such as Figure 14 As shown, the intra-pixel capacitor FC includes a semiconductor region 18a of a second conductivity type (e.g., N-type) formed in the semiconductor substrate 12 and an electrode 18b disposed opposite to the semiconductor region 18a through an insulating film 15. The intra-pixel capacitor FC is surrounded by an element separation portion 16. The intra-pixel capacitor FC is disposed at a position opposite to the vertical gate electrode VG through the element separation portion 16. For example, as Figure 14 As shown, the drain of the transmission transistor TGS includes a semiconductor region 18c. The semiconductor region 18c is disposed adjacent to the intra-pixel capacitor FC across the element separation portion 16. The semiconductor region 18c is disposed as a semiconductor region of a second conductivity type (e.g., N-type) within the semiconductor substrate 12. A portion of the charge accumulated in the photodiode PD moves to the intra-pixel capacitor FC via a metal wiring 11a electrically connected to the semiconductor region 18c.

[0102] In this modified example, the in-pixel capacitance FC and the transmission transistor TGS are formed on the top surface (formation surface 11B) of the semiconductor substrate 12. In this case, for example, as... Figure 14As shown, the element separation portion 16 is provided between the pixel in-capacitor FC and the vertical gate electrode VG or between the pixel in-capacitor FC and the transfer transistor TGS. This causes the element separation portion 16 to electrically separate the transfer transistor TRX and the transfer transistor TGS from the pixel in-capacitor FC. Here, for example, as Figure 14 As shown, the element separation portion 16 is provided in the vicinity of the vertical gate electrode VG. Even in the case where the element separation portion 16 is provided in the vicinity of the vertical gate electrode VG in this way, the dark current suppression and the transfer characteristic improvement can be achieved as in the above-described embodiments.

[0103] <3. Applicable Cases>

[0104] Figure 15 An example of a schematic configuration of an imaging system 2 including the solid-state imaging device 1 according to the above-described embodiments and modifications thereof is shown. The imaging system 2 corresponds to a specific example of the “electronic apparatus” according to the present disclosure.

[0105] The imaging system 2 is, for example, an electronic apparatus that is an imaging device such as a digital still camera or a video camera, a portable terminal apparatus such as a smartphone or a tablet terminal. The imaging system 2 includes, for example, the solid-state imaging device 1 according to the above-described embodiments and modifications thereof, an optical system 31, a shutter device 32, a control circuit 33, a DSP circuit 34, a frame memory 35, a display portion 36, a storage portion 37, an operation portion 38, and a power supply portion 39. In the imaging system 2, the solid-state imaging device 1, the shutter device 32, the control circuit 33, the DSP circuit 34, the frame memory 35, the display portion 36, the storage portion 37, the operation portion 38, and the power supply portion 39 according to the above-described embodiments and modifications thereof are connected to each other via a bus L.

[0106] The optical system 31 includes one or a plurality of lenses. The optical system 31 guides light (incident light) from a subject to the solid-state imaging device 1 to form an image on a light-receiving surface of the solid-state imaging device 1. The shutter device 32 is arranged between the optical system 31 and the solid-state imaging device 1 and controls a light irradiation period and a light blocking period of the solid-state imaging device 1 under the control of the control circuit 33. The solid-state imaging device 1 accumulates signal charges for a certain period according to light that forms an image on the light-receiving surface via the optical system 31 and the shutter device 32. The signal charges accumulated in the solid-state imaging device 1 are transferred to the DSP circuit 34 as a pixel signal (image data) according to a drive signal (timing signal) supplied from the control circuit 33. In other words, the solid-state imaging device 1 receives image light (incident light) incident via the optical system 31 and the shutter device 32, and outputs a pixel signal corresponding to the received image light (incident light) to the DSP circuit 34. The control circuit 33 outputs a drive signal for controlling a transfer operation of the solid-state imaging device 1 and a shutter operation of the shutter device 32, and drives the solid-state imaging device 1 and the shutter device 32.

[0107] The DSP circuit 34 is a signal processing circuit that processes pixel signals (image data) output from the solid-state imaging device 1. The frame memory 35 temporarily holds image data processed by the DSP circuit 34 in units of frames. The display section 36 includes, for example, a panel-type display device such as a liquid crystal panel or an organic electroluminescence (EL) panel, and displays a moving image or a still image captured by the solid-state imaging device 1. The storage section 37 records image data of a moving image or a still image captured by the solid-state imaging device 1 in a recording medium such as a semiconductor memory or a hard disk. The operation section 38 issues an operation instruction for various functions of the imaging system 2 according to a user’s operation. The power supply section 39 supplies various power sources for operation to the solid-state imaging device 1, the shutter device 32, the control circuit 33, the DSP circuit 34, the frame memory 35, the display section 36, the storage section 37, and the operation section 38, and the like, appropriately.

[0108] Next, the imaging step in the imaging system 2 will be described.

[0109] Figure 16 An example of a flow of an imaging operation in the imaging system 2 is shown. The user gives an instruction on imaging start by operating the operation section 38 (step S101). Then, the operation section 38 sends an imaging instruction to the control circuit 33 (step S102). Upon receiving the imaging instruction, the control circuit 33 starts to control the shutter device 32 and the solid-state imaging device 1. The solid-state imaging device 1 (specifically, the system control circuit 24) performs imaging in a predetermined imaging scheme under the control of the control circuit 33 (step S103). The shutter device 32 controls the light irradiation period and the light shielding period to the solid-state imaging device 1 under the control of the control circuit 33.

[0110] The solid-state imaging device 1 outputs image data obtained by imaging to the DSP circuit 34. Here, the image data is data of all pixels of a pixel signal generated on the basis of charges temporarily held in the floating diffusion section FD. The DSP circuit 34 performs predetermined signal processing (for example, noise reduction processing, and the like) on the basis of the image data input from the solid-state imaging device 1 (step S104). The DSP circuit 34 causes the frame memory 35 to hold the image data subjected to the predetermined signal processing, and the frame memory 35 causes the storage section 37 to store the image data (step S105). In this way, imaging in the imaging system 2 is performed.

[0111] In the present application example, the solid-state imaging device 1 according to any one of the above-described embodiments and modifications thereof is applied to the imaging system 2. This can obtain a high-definition image with less noise.

[0112] [4. Application Example]

[0113] [Application Example 1]

[0114] The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be implemented as a device mounted on any type of moving body such as a car, an electric car, a hybrid electric car, a motorcycle, a bicycle, a personal mobility device, an airplane, an unmanned aerial vehicle, a ship, a robot, or the like.

[0115] Figure 17 is a block diagram of a schematic configuration example of a vehicle control system that is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0116] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, a vehicle exterior information detection unit 12030, a vehicle interior information detection unit 12040, and an integrated control unit 12050. Further, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio / image output unit 12052, and a vehicle-mounted network interface (I / F) 12053 are shown. Figure 17

[0117] The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle in accordance with various programs. For example, the drive system control unit 12010 functions as a control device for a drive force generation device such as an internal combustion engine or a drive motor 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, a brake device for generating the braking force of the vehicle.

[0118] The body system control unit 12020 controls the operation of various devices mounted to the vehicle body in accordance with various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as a head lamp, a tail lamp, a brake lamp, a turn signal lamp, or a fog lamp. In this case, radio waves or signals of various switches transmitted from a portable device for replacing a key can be input to the body system control unit 12020. The body system control unit 12020 receives the input of the radio waves or the signals and controls the door lock device, the power window device, the lamps, and the like of the vehicle.

[0119] ​The vehicle exterior information detection unit 12030 detects information outside the vehicle including the vehicle control system 12000. For example, an imaging unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to capture an image of the outside of the vehicle, and receives the captured image. The vehicle exterior information detection unit 12030 can perform object detection processing or distance detection processing, such as a person, a car, an obstacle, a sign, a character on a road, and the like, on the basis of the received image.

[0120] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of received light. The imaging unit 12031 can output the electrical signal as an image, or can output the electrical signal as ranging information. Furthermore, the light received by the imaging unit 12031 can be visible light or invisible light such as infrared rays.

[0121] The vehicle interior information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the vehicle interior information detection unit 12040. For example, the driver state detection unit 12041 includes a camera that images the driver. On the basis of detection information input from the driver state detection unit 12041, the vehicle interior information detection unit 12040 can calculate the degree of fatigue or concentration of the driver, or can determine whether the driver is dozing off.

[0122] The microcomputer 12051 can calculate a control target value of a driving force generation device, a steering mechanism, or a braking device on the basis of information inside and outside the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and can output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control to realize the function of an advanced driver assistance system (ADAS) including collision avoidance or mitigation of the vehicle, follow-up travel based on the distance between vehicles, vehicle speed maintenance travel, vehicle collision warning, and lane departure warning of the vehicle, and the like.

[0123] Furthermore, the microcomputer 12051 can perform cooperative control to realize automatic driving in which the vehicle autonomously travels without depending on the operation of the driver, or the like, by controlling the driving force generation device, the steering mechanism, the braking device, and the like on the basis of information about the surroundings of the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040.

[0124] Further, the microcomputer 12051 can output a control command to the body system control unit 12020 on the basis of information outside the vehicle obtained by the outside information detection unit 12030. For example, the microcomputer 12051 can perform coordinated control to achieve glare prevention such as switching a high beam to a low beam by controlling a headlamp in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030.

[0125] Further, the microcomputer 12051 can output a control command to the body system control unit 12020 on the basis of information outside the vehicle obtained by the outside information detection unit 12030. For example, the microcomputer 12051 can perform coordinated control to achieve glare prevention such as switching a high beam to a low beam by controlling a headlamp in accordance with the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030.

[0126] The audio / image output unit 12052 transmits an output signal of at least one of audio and image to an output device capable of visually or aurally notifying information outside the vehicle or a passenger in the vehicle. In Figure 17 In the example, as the output device, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are shown. The display unit 12062 can include at least one of a vehicle-mounted display and a head-up display, for example.

[0127] Figure 18 is a diagram showing an example of a mounting position of the imaging unit 12031.

[0128] In Figure 18 , the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0129] The imaging units 12101, 12102, 12103, 12104, and 12105 are disposed at positions such as the front of the vehicle 12100, a side mirror, a rear bumper, a rear door, and the upper portion of a windshield in the vehicle, for example. The imaging unit 12101 disposed at the front of the vehicle and the imaging unit 12105 disposed at the upper portion of the windshield in the vehicle mainly obtain images of the front of the vehicle 12100. The imaging units 12102 and 12103 disposed at the side mirror mainly obtain images of the side of the vehicle 12100. The imaging unit 12104 disposed at the rear bumper or the rear door mainly obtains images of the rear of the vehicle 12100. The imaging unit 12105 disposed at the upper portion of the windshield in the vehicle is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic signal, a traffic sign, a lane, and the like.

[0130] Further, Figure 18Examples of imaging ranges of the imaging units 12101 to 12104 are shown. The imaging range 12111 represents an imaging range of the imaging unit 12101 provided at the vehicle front. The imaging ranges 12112 and 12113 respectively represent imaging ranges of the imaging units 12102 and 12103 provided at the side mirrors. The imaging range 12114 represents an imaging range of the imaging unit 12104 provided at the rear bumper or the rear door. A bird's-eye image of the vehicle 12100 viewed from above is obtained, for example, by superimposing image data captured by the imaging units 12101 to 12104.

[0131] At least one of the imaging units 12101 to 12104 can have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 can be a stereo camera including a plurality of imaging elements, or can be an imaging element having pixels for phase difference detection.

[0132] For example, based on distance information obtained from the imaging units 12101 to 12104, by obtaining the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the temporal change in distance (relative speed with respect to the vehicle 12100), the microcomputer 12051 extracts a three-dimensional object that is closest on the travel route of the vehicle 12100 and that travels at a predetermined speed (for example, 0 km / h or more) in substantially the same direction as the vehicle 12100 as a preceding vehicle. Further, the microcomputer 12051 can set a vehicle-to-vehicle distance that is secured in advance with respect to the preceding vehicle, and can perform automatic brake control (including follow-up travel stop control), automatic acceleration control (including follow-up travel start control), and the like. Thus, coordinated control for automatic driving and the like in which the vehicle autonomously travels without relying on the operation of the driver can be performed.

[0133] For example, based on distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can classify three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, extract the three-dimensional object data, and automatically avoid obstacles using the three-dimensional object data. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that can be visually recognized by the driver of the vehicle 12100 and obstacles that are difficult to visually recognize. Then, the microcomputer 12051 judges a collision risk indicating a degree of danger of collision with each obstacle. When the collision risk is equal to or higher than a set value and there is a possibility of collision, a warning can be output to the driver via the audio speaker 12061 and the display unit 12062, and forced deceleration or evasive steering can be performed via the drive system control unit 12010. The microcomputer 12051 can thus assist the driver to avoid collision.

[0134] At least one of the imaging units 12101 to 12104 can be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by judging whether a pedestrian is present in an image captured by the imaging units 12101 to 12104. For example, the recognition of a pedestrian is performed by a step of extracting feature points in an image captured by the imaging units 12101 to 12104 as infrared cameras and a step of performing pattern matching processing on a series of feature points indicating the outline of an object to judge whether the object is a pedestrian. When the microcomputer 12051 judges that a pedestrian is present in an image captured by the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 causes the display unit 12062 to superimpose and display a quadrangular outline for emphasis on the recognized pedestrian. In addition, the audio / image output unit 12052 can also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0135] Examples of a mobile body control system to which the technology according to the present disclosure is applicable have been described above. The technology according to the present disclosure is applicable to the imaging unit 12031 among the above-described configurations. Specifically, the solid-state imaging device 1 according to the above-described embodiments and modified examples thereof is applicable to the imaging unit 12031. The application of the technology according to the present disclosure to the imaging unit 12031 can provide a mobile body control system that uses a high-definition image with less noise.

[0136] [Application Example 2]

[0137] Figure 19 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) is applicable.

[0138] Figure 19 A state in which a surgeon (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000 is shown. As shown, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical instruments 11110 such as a gas tube 11111 and an energy device 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0139] The endoscope 11100 includes a lens barrel 11101 in which a region at a predetermined length from a distal end is inserted into a body cavity of the patient 11132 and a camera head 11102 connected to a proximal end of the lens barrel 11101. In the example shown, a rigid endoscope 11100 having a rigid lens barrel 11101 is shown. However, the endoscope 11100 can additionally be a flexible endoscope having a flexible lens barrel 11101.

[0140] The lens barrel 11101 has an opening at its distal end at which an objective lens is mounted. The light source device 11203 is connected to the endoscope 11100 so that light generated by the light source device 11203 is guided to the distal end of the lens barrel 11101 by a light guide extending into the inside of the lens barrel 11101 and emitted toward an observation object inside a body cavity of the patient 11132 via the objective lens. Note that the endoscope 11100 can be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0141] An optical system and an image pickup element are disposed inside the camera head 11102 so that reflected light (observation light) from the observation object is converged on the image pickup element by the optical system. The observation light is photoelectrically converted by the image pickup element to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to an observation image. The image signal is transmitted to the camera control unit (CCU) 11201 as RAW data.

[0142] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), and the like and comprehensively controls the operation of the endoscope 11100 and the display device 11202. Further, the CCU 11201 receives the image signal from the camera head 11102 and, for example, performs various image processing such as development processing (demosaicing processing) and the like for displaying an image based on the image signal on the image signal.

[0143] The display device 11202 displays an image based on the image signal processed by the CCU 11201 under the control of the CCU 11201.

[0144] The light source device 11203 includes, for example, a light source such as a light emitting diode (LED) and supplies irradiation light for imaging a surgical site or the like to the endoscope 11100.

[0145] The input device 11204 is an input interface for the endoscope surgery system 11000. The user can input various information and instructions to the endoscope surgery system 11000 via the input device 11204. For example, the user inputs an instruction or the like to change an image pickup condition (a type of irradiation light, a magnification, a focal distance, and the like) by using the endoscope 11100.

[0146] The treatment instrument control device 11205 controls the driving of the energy device 11112 for cauterization and incision of tissue, sealing of blood vessels, and the like. The pneumoperitoneum device 11206 injects gas into the body cavity of the patient 11132 via the pneumoperitoneum tube 11111 to inflate the body cavity of the patient 11132 for securing the field of view of the endoscope 11100 and securing the working space of the operator. The recorder 11207 is a device capable of recording various information related to surgery. The printer 11208 is a device capable of printing various information related to surgery in various forms such as text, images, graphics, and the like.

[0147] Note that the light source device 11203 that supplies irradiation light to the endoscope 11100 when the endoscope 11100 photographs the surgical site can include, for example, a white light source of an LED, a laser light source, or a combination thereof. In the case where the white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing of various colors (wavelengths) can be controlled with high precision, adjustment of the white balance of the picked-up image can be performed in the light source device 11203. Further, in this case, if laser light from each of the RGB laser light sources is irradiated onto the observation object in time division and the driving of the imaging element of the camera head 11102 is controlled in synchronization with the irradiation timing, then an image corresponding to each of RGB can also be picked up in time division. According to this method, a color image can be obtained without providing a color filter in the imaging element.

[0148] Further, the driving of the light source device 11203 can be controlled so as to change the intensity of light to be output at every predetermined time. By controlling the driving of the image pickup element of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in time division and synthesize the images, an image of high dynamic range having no shadow of underexposure and highlight of overexposure can be generated.

[0149] Further, the light source device 11203 can be configured to supply light of a predetermined wavelength band corresponding to special light observation. In the special light observation, for example, so-called narrow-band light observation (narrow-band imaging) is performed in which a predetermined tissue such as a blood vessel of a mucosal surface layer is imaged with high contrast by irradiating a light of a narrower band than an irradiation light (i.e., white light) at the time of normal observation by using wavelength dependency of light absorption in a body tissue. Alternatively, in the special light observation, fluorescence observation for obtaining an image by irradiating excitation light to generate fluorescence can be performed. In the fluorescence observation, for example, a body tissue can be irradiated with excitation light to observe fluorescence from the body tissue (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally injected into the body tissue and the body tissue is irradiated with excitation light corresponding to a fluorescence wavelength of the reagent to obtain a fluorescence image. The light source device 11203 can be configured to supply a narrow-band light and / or excitation light corresponding to such special light observation.

[0150] Figure 20 is a block diagram showing an example of functional configuration of the camera head 11102 and the CCU 11201. Figure 19

[0151] The camera head 11102 includes a lens unit 11401, an image pickup unit 11402, a driving unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are communicably connected to each other through a transmission cable 11400.

[0152] The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. The observation light received from the distal end of the lens barrel 11101 is guided to the camera head 11102 and incident to the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focus lens.

[0153] ​The number of image pickup elements included in the image pickup unit 11402 can be one (single board type) or a plurality (multi board type). When the image pickup unit 11402 is configured as a multi board type, for example, image signals corresponding to R, G, and B respectively can be generated by the image pickup elements, and a color image can be obtained by combining the image signals. The image pickup unit 11402 can also be configured to have a pair of image pickup elements for acquiring respective image signals for right and left eyes in preparation for three-dimensional (3D) display. If 3D display is performed, the operator 11131 can more accurately grasp the depth of the body tissue in the surgery site. Note that when the image pickup unit 11402 is configured as a multi board type, a plurality of system lens units 11401 are provided corresponding to the respective image pickup elements.

[0154] Further, the image pickup unit 11402 does not necessarily have to be provided on the camera head 11102. For example, the image pickup unit 11402 can be provided just behind the objective lens inside the lens barrel 11101.

[0155] The drive unit 11403 includes an actuator and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. Accordingly, the magnification and the focus of the image captured by the image pickup unit 11402 can be appropriately adjusted.

[0156] The communication unit 11404 includes a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal acquired from the image pickup unit 11402 to the CCU 11201 as RAW data via the transmission cable 11400.

[0157] Further, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. The control signal includes, for example, information on the image pickup conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and the focus of the captured image, and the like.

[0158] Note that the image pickup conditions such as the frame rate, the exposure value, the magnification, and the focus can be appropriately specified by the user or can be automatically set by the control unit 11413 of the CCU 11201 based on the captured image signal. In the latter case, an automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are installed in the endoscope 11100.

[0159] The camera control unit 11405 controls driving of the camera 11102 on the basis of a control signal received from the CCU 11201 via the communication unit 11404.

[0160] The communication unit 11411 includes a communication device for transmitting and receiving various information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 via the transmission cable 11400.

[0161] Further, the communication unit 11411 transmits a control signal for controlling driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0162] The image processing unit 11412 performs various image processing on an image signal that is RAW data transmitted from the camera 11102.

[0163] The control unit 11413 performs various controls related to image pickup of a surgical site and the like by using the endoscope 11100 and display of a captured image obtained by imaging the surgical site and the like. For example, the control unit 11413 generates a control signal for controlling driving of the camera 11102.

[0164] Further, the control unit 11413 causes the display device 11202 to display a captured image of a surgical site and the like on the basis of an image signal that has been subjected to image processing by the image processing unit 11412. At this time, the control unit 11413 can recognize various objects within the captured image by using various image recognition techniques. For example, the control unit 11413 can recognize a surgical instrument such as forceps, a specific living body site, bleeding, fog when the energy device 11112 is used, and the like by detecting an edge shape, a color, and the like of an object included in the captured image. When the captured image is displayed in the display device 11202, by using the recognition result, the control unit 11413 can superimpose and display various surgery support information related to an image of the surgical site. When the surgery support information is displayed in a superimposed manner and presented to the surgeon 11131, the burden of the surgeon 11131 can be alleviated, and the surgeon 11131 can reliably perform surgery.

[0165] The transmission cable 11400 that connects the camera 11102 and the CCU 11201 to each other is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable for electrical and optical communication.

[0166] Here, in the example shown, communication is performed by wire using the transmission cable 11400, but communication between the camera 11102 and the CCU 11201 can be performed wirelessly.

[0167] Examples of the endoscope surgery system to which the technology according to the present disclosure is applicable have been described above. The technology according to the present disclosure is appropriately applied to the image pickup unit 11402 provided for the camera head 11102 of the endoscope 11100 among the above-described configurations. By applying the technology according to the present disclosure to the image pickup unit 11402, the image pickup unit 11402 can be miniaturized or have high definition, and thus an endoscope 11100 using a high-definition image with less noise can be provided.

[0168] Although the present disclosure has been described with reference to the embodiments, modifications, applications, and application examples, the present disclosure is not limited to the embodiments and the like, and various modifications can be made. Note that the effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure can have effects other than those described in this specification.

[0169] Further, the present disclosure can also have the following configurations.

[0170] (1) A solid-state imaging device comprising

[0171] a semiconductor substrate including a light-receiving surface and a plurality of pixels disposed opposite the light-receiving surface, wherein

[0172] each of the pixels includes

[0173] a photoelectric conversion section that performs photoelectric conversion on light incident via the light-receiving surface,

[0174] a charge holding section that is formed as a semiconductor region of a second conductivity type different from a first conductivity type within a semiconductor region of the first conductivity type in the semiconductor substrate, and holds a charge transferred from the photoelectric conversion section,

[0175] a transfer transistor including a vertical gate electrode reaching the photoelectric conversion section and a gate insulating film in contact with the vertical gate electrode, the gate insulating film being formed on a surface of the semiconductor substrate opposite the light-receiving surface, the transfer transistor transferring the charge from the photoelectric conversion section to the charge holding section,

[0176] an element separation section formed close to the surface of the semiconductor substrate opposite the light-receiving surface, and containing an oxide film insulator, and

[0177] a semiconductor layer in contact with side surfaces and a bottom surface of the element separation section and the gate insulating film, and having an impurity concentration of the first conductivity type higher than that of the semiconductor region of the first conductivity type,

[0178] At least a portion of the element separation portion is disposed apart from the vertical gate electrode with respect to a portion of the semiconductor layer that contacts the gate insulating film.

[0179] (2) The solid-state imaging device according to (1), wherein at least the portion of the element separation portion is disposed apart from a portion of the vertical gate electrode other than an upper end portion, with respect to a portion of the semiconductor layer that contacts the gate insulating film.

[0180] (3) The solid-state imaging device according to (2), wherein at least the portion of the element separation portion is disposed apart from the vertical gate electrode, as viewed in a normal direction of the semiconductor substrate.

[0181] (4) The solid-state imaging device according to (3), wherein any portion of the element separation portion is disposed apart from the vertical gate electrode, as viewed in the normal direction of the semiconductor substrate.

[0182] (5) The solid-state imaging device according to any one of (1) to (4), wherein the semiconductor layer is disposed apart from the vertical gate electrode, as viewed in the normal direction of the semiconductor substrate.

[0183] (6) The solid-state imaging device according to any one of (1) to (5), wherein a portion of the photoelectric conversion portion extends toward a surface of the semiconductor substrate opposite the light-receiving surface along the vertical gate electrode.

[0184] (7) The solid-state imaging device according to any one of (1) to (6), further comprising an in-pixel capacitance disposed at a position opposite the vertical gate electrode with respect to the element separation portion, and accumulating a charge transferred from the photoelectric conversion portion.

[0185] (8) An electronic apparatus comprising:

[0186] a solid-state imaging device that outputs a pixel signal corresponding to incident light; and

[0187] a signal processing circuit that processes the pixel signal, wherein

[0188] the solid-state imaging device includes

[0189] a semiconductor substrate including a light-receiving surface and a plurality of pixels disposed opposite the light-receiving surface, wherein

[0190] each of the pixels includes

[0191] a photoelectric conversion section that performs photoelectric conversion on light that has been incident via the light-receiving surface,

[0192] a charge holding section that is formed as a semiconductor region of a second conductivity type different from the first conductivity type within a semiconductor region of the first conductivity type in the semiconductor substrate, and holds charges transferred from the photoelectric conversion section,

[0193] a transfer transistor that includes a vertical gate electrode that reaches the photoelectric conversion section, and a gate insulating film that is in contact with the vertical gate electrode, the gate insulating film being formed on a surface of the semiconductor substrate opposite the light-receiving surface, the transfer transistor transferring charges from the photoelectric conversion section to the charge holding section,

[0194] a device separation section that is formed near a surface of the semiconductor substrate opposite the light-receiving surface, and contains an oxide film insulator, and

[0195] a semiconductor layer that is in contact with side surfaces and a bottom surface of the device separation section and the gate insulating film, and has an impurity concentration of the first conductivity type that is higher than an impurity concentration of the semiconductor region of the first conductivity type,

[0196] At least a portion of the device separation section is disposed apart from the vertical gate electrode with a portion of the semiconductor layer that is in contact with the gate insulating film interposed therebetween.

[0197] The solid-state imaging device and the electronic apparatus according to various embodiments of the present disclosure each are provided with a vertical transistor (transfer transistor TRX) including a vertical gate electrode VG, and at least a portion of the device separation section 16 is disposed apart from a portion of the vertical gate electrode VG other than an upper end portion (umbrella-shaped portion) with the semiconductor layer 17 interposed therebetween. This makes it possible to improve transfer characteristics while suppressing dark current. Note that the effects of the present technology are not necessarily limited to those described here, but can include any of the effects described in this specification.

[0198] This application claims the benefit of Japanese Patent Application No. 2019-226378, filed December 16, 2019, which is hereby incorporated by reference herein in its entirety.

[0199] Those skilled in the art will appreciate that various modifications, combinations, sub-combinations and alterations can occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.

Claims

1. A solid-state imaging device, comprising: A semiconductor substrate, the semiconductor substrate including a light-receiving surface and a plurality of pixels disposed opposite to the light-receiving surface, wherein, Each pixel includes The photoelectric conversion unit performs photoelectric conversion on light incident via the light receiving surface. A charge holding section is formed within a semiconductor region of a first conductivity type in the semiconductor substrate as a semiconductor region of a second conductivity type, different from the first conductivity type, and retains the charge transferred from the photoelectric conversion section. A transmission transistor includes a vertical gate electrode and a gate insulating film in contact with the vertical gate electrode, the vertical gate electrode reaching the photoelectric conversion section, and the gate insulating film formed on the surface of the semiconductor substrate opposite to the light-receiving surface. The transmission transistor transfers charge from the photoelectric conversion section to the charge holding section. A component separation section is formed near the surface of the semiconductor substrate opposite to the light-receiving surface, and includes an oxide insulator. A semiconductor layer, which contacts the side and bottom surfaces of the device separation portion, is disposed within a layer between the semiconductor region of the first conductivity type and the gate insulating film and is formed to contact the semiconductor region of the first conductivity type and the gate insulating film, and has an impurity concentration of the first conductivity type that is higher than that of the semiconductor region of the first conductivity type. At least a portion of the element separation section, separated from the vertical gate electrode by the portion in contact with the gate insulating film through the semiconductor layer, is configured separately. When viewed from the normal direction of the semiconductor substrate, the semiconductor layer extends from the side and bottom surfaces of the element separation portion to a position overlapping with the upper end of the vertical gate electrode.

2. The solid-state imaging device according to claim 1, wherein, At least the portion of the element separation section that contacts the gate insulating film across the semiconductor layer is configured separately from the portion other than the upper end of the vertical gate electrode.

3. The solid-state imaging device according to claim 2, wherein, When viewed from the normal direction of the semiconductor substrate, at least this portion of the element separation portion is disposed separately from the vertical gate electrode.

4. The solid-state imaging device according to claim 3, wherein, When viewed from the normal direction of the semiconductor substrate, any portion of the element separation portion is arranged separately from the vertical gate electrode.

5. The solid-state imaging device according to any one of claims 1 to 4, wherein, A portion of the photoelectric conversion section extends along the vertical gate electrode toward the surface of the semiconductor substrate opposite the light-receiving surface.

6. The solid-state imaging apparatus according to any one of claims 1 to 4 further includes an in-pixel capacitor, the in-pixel capacitor being disposed across the element separation portion at a position opposite to the vertical gate electrode, and accumulating the charge transferred from the photoelectric conversion portion.

7. An electronic device, comprising: The solid-state imaging device according to any one of claims 1 to 6, wherein the solid-state imaging device outputs a pixel signal corresponding to the incident light; and A signal processing circuit that processes the pixel signal.

Images