Light detection device and electronic apparatus

Abstract

The quantum efficiency of photoelectric conversion is improved. The light detection device includes: a photoelectric conversion unit that is provided in a semiconductor substrate and photoelectrically converts incident light; a charge holding unit which is provided in the semiconductor substrate and holds charges generated by the photoelectric conversion; and a charge transfer portion provided in the semiconductor substrate, configured of a MOS transistor including a gate electrode having a vertical electrode portion, and configured to transfer the charge of the photoelectric conversion portion to the charge holding portion, the vertical electrode portion is configured in a shape such that the bottom portion extends to the vicinity of the back surface of the semiconductor substrate, and is configured to have a refractive index lower than a refractive index of the semiconductor substrate.

Description

Technical Field

[0001] The present disclosure relates to a light detection device and an electronic device. Background Art

[0002] In a light detection device such as an imaging element, a photoelectric conversion unit arranged in a pixel generates an electric charge according to incident light during an exposure period, and after the exposure period has passed, a charge transfer unit transfers the generated electric charge to a charge holding unit. Thereafter, a circuit arranged in the pixel generates an image signal based on the electric charge held in the charge holding unit. For such an imaging element, an imaging element in which a photoelectric conversion unit is arranged on the back side of a semiconductor substrate is used. In this imaging element, a charge transfer unit is used that transfers the electric charge generated by the photoelectric conversion unit to a charge holding unit arranged on the front side of the semiconductor substrate. For example, a solid-state imaging element including a charge transfer unit has been proposed, the charge transfer unit including a transfer transistor having a vertical gate electrode embedded in the surface of the semiconductor substrate (for example, see Patent Document 1). Citation List Patent Literature

[0003] Patent Document 1: WO 2019 / 093149 A Summary of the Invention Technical issues

[0004] However, in the conventional technology described above, since light incident from the back side of the semiconductor substrate is absorbed by the vertical gate electrode, there is a problem of reduced photoelectric conversion efficiency. Consequently, there is a problem of reduced sensitivity.

[0005] Therefore, the present disclosure proposes a light detection device and an electronic device for improving the quantum efficiency of photoelectric conversion. Solution to the problem

[0006] According to the present disclosure, the light detection device includes: a photoelectric conversion unit, which is arranged in a semiconductor substrate and performs photoelectric conversion on incident light; a charge holding unit, which is arranged in the semiconductor substrate and holds the charge generated by the photoelectric conversion; and a charge transfer unit, which is arranged in the semiconductor substrate and is constructed by a MOS transistor and is constructed to transfer the charge of the photoelectric conversion unit to the charge holding unit, the MOS transistor including a gate electrode, the gate electrode having a vertical electrode portion, the vertical electrode portion being constructed in a shape such that the bottom extends to the vicinity of the back surface of the semiconductor substrate and being constructed to have a refractive index lower than the refractive index of the semiconductor substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 : is a diagram showing a schematic configuration example of a light detection device according to the first embodiment of the present disclosure. Figure 2 is a diagram illustrating another schematic configuration example of the light detection device according to the first embodiment of the present disclosure. Figure 3 is a diagram illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. Figure 4 is a diagram illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. Figure 5 is a diagram illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. Figure 6 is a diagram illustrating a configuration example of a pixel according to a second embodiment of the present disclosure. Figure 7 is a diagram illustrating a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 8 is a diagram illustrating a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 9 is a diagram illustrating a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 10 is a diagram illustrating a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 11 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figure 12 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figure 13 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figure 14 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figure 15 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figure 16 is a block diagram illustrating a configuration example of an imaging device mounted on an electronic device. Figure 17 is a block diagram showing a schematic configuration example of a vehicle control system as an example of a mobile body control system to which the technology according to the embodiment of the present disclosure can be applied. Figure 18 1 is a diagram showing an example of an installation position of an imaging section. Figure 19 : is a diagram showing a schematic configuration example of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (the present technology) can be applied. Figure 20 It shows Figure 19 A block diagram showing an example of the functional configuration of a camera and a CCU is shown. DETAILED DESCRIPTION

[0008] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The description will be given in the following order. Note that in each of the following embodiments, the same components are represented by the same drawings, and repeated descriptions are omitted. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Modification 5. Structure of electronic equipment 6. Application examples of mobile objects 7. Application examples of endoscopic surgery systems

[0009] (1. First embodiment) [Structure of Photodetection Device] Figure 1 1 is a diagram showing a schematic configuration example of a light detecting device according to a first embodiment of the present disclosure. Figure 1 As shown, the light detection device 1 of this example includes a pixel array portion (so-called imaging area) 13 and a peripheral circuit portion, in which pixels 12 including a plurality of photoelectric conversion portions are regularly and two-dimensionally arranged on a semiconductor substrate 11 (e.g., a silicon substrate). The pixel 12 includes, for example, a photodiode serving as a photoelectric conversion portion and a plurality of pixel transistors (so-called MOS transistors). The plurality of pixel transistors may include, for example, three transistors: a transfer transistor, a reset transistor, and an amplifying transistor. In addition, a selection transistor may be added to form four transistors. The pixel 12 may have a shared pixel structure. The pixel sharing structure includes a plurality of photodiodes, a plurality of transfer transistors, a shared floating diffusion region, and a shared pixel transistor. Note that the light detection device 1 is an example of a "semiconductor device" of the present disclosure.

[0010] The peripheral circuit section includes a vertical drive circuit 33 , a column signal processing circuit 34 , a horizontal drive circuit 35 , an output circuit 37 , a control circuit 36 ​​, and the like.

[0011] The control circuit 36 ​​receives an input clock and data indicating an operating mode, etc., and outputs data such as internal information of the imaging element. Specifically, the control circuit 36 ​​generates a clock signal or a control signal based on the vertical synchronization signal, the horizontal synchronization signal, and the master clock, which serves as an operating reference for the vertical drive circuit 33, the column signal processing circuit 34, the horizontal drive circuit 35, and the like. These signals are then input to the vertical drive circuit 33, the column signal processing circuit 34, the horizontal drive circuit 35, and the like.

[0012] The vertical drive circuit 33 includes, for example, a shift register, selects the pixel drive line 23, supplies a pulse for driving the pixel to the selected pixel drive line, and drives the pixel in units of rows. Specifically, the vertical drive circuit 33 sequentially selects and scans each pixel 12 in the pixel array section 13 in the vertical direction in units of rows, and supplies a pixel signal based on the signal charge generated in the photoelectric conversion section (e.g., photodiode) of each pixel 12 according to the amount of received light to the column signal processing circuit 34 via the vertical signal line 24.

[0013] For example, the column signal processing circuit 34 is arranged for each column of the pixels 12, and performs signal processing such as noise elimination on the signals output from one row of pixels 12 for each pixel column. That is, the column signal processing circuit 34 performs signal processing such as correlated double sampling (CDS) for eliminating fixed pattern noise unique to the pixels 12, signal amplification, and AD conversion. A horizontal selection switch (not shown) is connected and provided between the output stage of the column signal processing circuit 34 and the horizontal signal line 38.

[0014] The horizontal drive circuit 35 includes, for example, a shift register, sequentially selects each column signal processing circuit 34 by sequentially outputting horizontal scanning pulses, and causes each column signal processing circuit 34 to output a pixel signal to a horizontal signal line 38 .

[0015] The output circuit 37 processes the signals sequentially input from each column signal processing circuit 34 via the horizontal signal line 38 and outputs the processed signals. For example, the output circuit 37 may only perform buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal 39 exchanges signals with the outside.

[0016] Note that the accompanying drawings illustrate an example in which the light detecting device 1 is formed on a semiconductor substrate 11. The light detecting device 1 may also include multiple semiconductor substrates. By stacking multiple substrates constituting the light detecting device 1, the size (area) of the light detecting device 1 can be reduced. An example of this case will be described below.

[0017] [Another Configuration of the Photodetection Device] Figure 2 This figure shows another schematic configuration example of a light detection device according to the first embodiment of the present disclosure. The light detection device 1 in the figure includes three substrates (a first substrate 10, a second substrate 20, and a third substrate 30). The light detection device 1 has a three-dimensional structure formed by joining these three substrates (the first substrate 10, the second substrate 20, and the third substrate 30). The first substrate 10, the second substrate 20, and the third substrate 30 are stacked in this order.

[0018] The first substrate 10 includes a plurality of pixels 12 that perform photoelectric conversion on a semiconductor substrate 11. The plurality of pixels 12 are arranged in a matrix form in a pixel array portion 13 of the first substrate 10. The second substrate 20 includes a pixel circuit 22 for each of the four pixels 12 on the semiconductor substrate 21, and the pixel circuit 22 outputs a pixel signal based on the charge output from the pixel 12. The second substrate 20 includes a plurality of pixel drive lines 23 extending in the row direction and a plurality of vertical signal lines 24 extending in the column direction. The third substrate 30 includes a logic circuit 32 that processes pixel signals on a semiconductor substrate 31. The logic circuit 32 includes, for example, a vertical drive circuit 33, a column signal processing circuit 34, a horizontal drive circuit 35, and a control circuit 36. The logic circuit 32 (specifically, the horizontal drive circuit 35) outputs the output voltage Vout of each pixel 12 to the outside. In the logic circuit 32 , for example, a low resistance region made of silicide (eg, CoSi 2 or NiSi) formed using a self-aligned silicide (salicide) process may be formed on the surface of the impurity diffusion region in contact with the source electrode and the drain electrode.

[0019] For example, the vertical drive circuit 33 sequentially selects a plurality of pixels 12 row by row. The column signal processing circuit 34 performs, for example, correlated double sampling (CDS) processing on the pixel signal output by each pixel 12 in the row selected by the vertical drive circuit 33. The column signal processing circuit 34 extracts the signal level of the pixel signal by performing, for example, CDS processing, and holds pixel data corresponding to the amount of light received by each pixel 12. For example, the horizontal drive circuit 35 sequentially outputs the pixel data held in the column signal processing circuit 34 to the outside. For example, the control circuit 36 ​​controls the driving of each module (the vertical drive circuit 33, the column signal processing circuit 34, and the horizontal drive circuit 35) in the logic circuit 32.

[0020] Figure 3 is a diagram illustrating a configuration example of a pixel according to an embodiment of the present disclosure. Figure 3 1 is a circuit diagram showing a configuration example of the pixel 12, and shows an example of the pixel 12 and the readout circuit 22. Figure 3 As shown, a case where four pixels 12 share one readout circuit 22 will be described. Here, “share” means that the outputs of the four pixels 12 are input to the common readout circuit 22. The column signal processing circuit 34 corresponds to a specific example of the “processing circuit” of the present disclosure.

[0021] Each pixel 12 has common components. Figure 3In order to distinguish the components of each pixel 12, an identification number (1, 2, 3, and 4) is added to the end of the reference numeral of the component of each pixel 12. Hereinafter, when it is necessary to distinguish the components of each pixel 12, an identification number is assigned to the end of the reference numeral of the component of each pixel 12; however, when it is not necessary to distinguish the components of each pixel 12, the identification number is omitted from the end of the reference numeral of the component of each pixel 12. Note that the light detection device 1 is a specific example of the "semiconductor device" of the present disclosure.

[0022] Each pixel 12 includes, for example, a photodiode PD, a charge transfer unit TR electrically connected to the photodiode PD, and a floating diffusion region FD constituting a charge holding unit for temporarily holding the charge output from the photodiode PD via the charge transfer unit TR. The photodiode PD corresponds to a specific example of a “photoelectric conversion element” of the present disclosure. The photodiode PD performs photoelectric conversion to generate a charge corresponding to the amount of received light. The cathode of the photodiode PD is electrically connected to the source of the charge transfer unit TR, and the anode of the photodiode PD is electrically connected to a reference potential line (for example, ground). The drain of the charge transfer unit TR is electrically connected to the floating diffusion region FD, and the gate of the charge transfer unit TR is electrically connected to the pixel drive line 23. The charge transfer unit TR is, for example, a metal oxide semiconductor (MOS) transistor.

[0023] The floating diffusion regions FD of each pixel 12 that share a readout circuit 22 are electrically connected to each other and to the input terminal of the common readout circuit 22. The readout circuit 22 includes, for example, a reset transistor RST, a selection transistor SEL, and an amplifier transistor AMP. Note that the selection transistor SEL can be omitted as needed. The source of the reset transistor RST (the input terminal of the readout circuit 22) is electrically connected to the floating diffusion region FD, and the drain of the reset transistor RST is electrically connected to the power supply line VDD and the drain of the amplifier transistor AMP. The gate of the reset transistor RST is electrically connected to the pixel drive line 23 (see Figure 2 ). The source of the amplifier transistor AMP is electrically connected to the drain of the selection transistor SEL, and the gate of the amplifier transistor AMP is electrically connected to the source of the reset transistor RST. The source of the selection transistor SEL (the output terminal of the readout circuit 22) is electrically connected to the vertical signal line 24, and the gate of the selection transistor SEL is electrically connected to the pixel drive line 23 (see Figure 2 ).

[0024] After being turned on, the charge transfer unit TR transfers the charge of the photodiode PD to the floating diffusion region FD. The reset transistor RST resets the potential of the floating diffusion region FD to a predetermined potential. After the reset transistor RST is turned on, the potential of the floating diffusion region FD is reset to the potential of the power supply line VDD. The select transistor SEL controls the timing of the pixel circuit 22 outputting the pixel signal. The amplifier transistor AMP generates a voltage signal corresponding to the charge level held in the floating diffusion region FD as a pixel signal. The amplifier transistor AMP constitutes a source follower amplifier and outputs a pixel signal having a voltage corresponding to the level of charge generated in the photodiode PD. When the select transistor SEL is turned on, the amplifier transistor AMP outputs a voltage corresponding to the potential of the floating diffusion region FD to the column signal processing circuit 34 via the vertical signal line 24. The reset transistor RST, the amplifier transistor AMP, and the select transistor SEL are, for example, MOS transistors. Note that the light detection device 1 is an example of a "semiconductor device" in the present disclosure. The column signal processing circuit 34 is an example of a "processing circuit" in the present disclosure.

[0025] [Pixel structure] Figure 4 is a diagram illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. Figure 3 is a diagram showing a configuration example of the pixels 12 arranged in the pixel array section 13. In addition, Figure 3 The pixels 12 are formed on a semiconductor substrate 120 corresponding to the semiconductor substrate 11. Figure 3 In the pixel 12, a photoelectric conversion unit 101 (not shown), a charge transfer unit 102 (corresponding to Figure 3 TR in) and the charge holding portion 103 (not shown). Figure 3 The vertical electrode portion 151 of the gate electrode 150 constituting the charge transfer portion 102 is shown. Figure 3 The vertical electrode portion 151 in FIG. 1 is configured as a rectangular example. The isolation portion 132 is arranged at the boundary of the pixel 12.

[0026] [Cross-sectional structure of a pixel] Figure 5 1 is a diagram illustrating an example configuration of a pixel according to the first embodiment of the present disclosure. This diagram is a schematic cross-sectional view illustrating an example configuration of pixel 12. Pixel 12 in the diagram includes a semiconductor substrate 120, a partition 132, insulating films 130 and 131, a wiring region 140, a color filter 190, and an on-chip lens 193.

[0027] The semiconductor substrate 120 is a semiconductor substrate on which elements and the like are provided. Figure 5The photoelectric conversion unit 101, the charge transfer unit 102, and the charge holding unit 103 are further provided on the semiconductor substrate 120. The semiconductor substrate 120 can be made of silicon (Si), for example. The photoelectric conversion unit 101 is provided in a well region formed in the semiconductor substrate 120. For convenience, it is assumed that Figure 5 The semiconductor substrate 120 in the p-type well region constitutes a p-type well region. By arranging n-type and p-type semiconductor regions in the p-type well region, an element (its diffusion layer) can be formed.

[0028] Figure 5 The rectangle shown in the semiconductor substrate 120 in FIG. 1 represents a semiconductor region. The photoelectric conversion unit 101 includes an n-type semiconductor region 121. Specifically, the photoelectric conversion unit 101 includes a photodiode formed of a pn junction formed at the interface between the semiconductor region 121 and its surrounding p-type well region.

[0029] The charge holding portion 103 includes a semiconductor region 124 configured to have a relatively high n-type impurity concentration. The semiconductor region 124 constitutes the above-mentioned floating diffusion region.

[0030] The charge transfer unit 102 includes semiconductor regions 121 and 124 and a gate electrode 150. The n-type semiconductor regions 121 and 124 correspond to the source and drain regions of the charge transfer unit 102. The gate electrode 150 includes a vertical electrode portion 151 and a flat electrode portion 159. The vertical electrode portion 151 is an electrode disposed within the semiconductor substrate 120, with its bottom portion extending to near the back surface of the semiconductor substrate 120. Furthermore, the flat electrode portion 159 is an electrode disposed on the front surface of the semiconductor substrate 120, with its bottom portion in contact with the vertical electrode portion 151. When a conduction voltage is applied to the gate electrode 150, a channel forms in the semiconductor region on the surface of the gate electrode 150, and the semiconductor regions 121 and 124 enter a conductive state. This establishes conduction between the photoelectric conversion unit 101 and the charge retention unit 103, and the charge in the photoelectric conversion unit 101 is transferred to the charge retention unit 103. In this way, the charge transfer unit 102 transfers charge along the thickness direction of the semiconductor substrate 120.

[0031] Insulating films 130 and 131 are provided on the front and back sides of semiconductor substrate 120, respectively. Insulating films 130 and 131 can be made of, for example, silicon oxide (SiO2) or silicon nitride (SiN). Note that a gate insulating film (not shown) is provided between gate electrode 150 and semiconductor substrate 120.

[0032] The isolation portion 132 is arranged at the boundary of the pixel 12 to isolate the pixel 12. The isolation portion 132 is formed into a shape that extends from near the front side of the semiconductor substrate 120 to the back side. The isolation portion 132 can be constructed by embedding an insulator such as SiO2 in a groove portion formed in the semiconductor substrate 120. Note that the semiconductor region 123 is provided in the region of the semiconductor substrate 120 that contacts the isolation portion 132. The semiconductor region 123 is a semiconductor region in which a relatively high p-type impurity concentration is conformally distributed. The semiconductor region 123 is a semiconductor region for pinning the interface state of the semiconductor substrate 120. In addition, the semiconductor region 122 is a semiconductor region in which a relatively high n-type impurity concentration is conformally distributed. The semiconductor regions 121 and 122 constitute the photoelectric conversion portion 101 that accumulates charges after photoelectric conversion.

[0033] The wiring region 140 is a region provided on the front surface side of the semiconductor substrate 120 , and wiring for transmitting signals of elements and the like is provided therein. Figure 5 The wiring region 140 in FIG. 1 includes an insulating layer 141 and wiring 142. Wiring 142 transmits signals to elements formed on the semiconductor substrate 120. Wiring 142 can be made of tungsten (W) or copper (Cu). Insulating layer 141 insulates the electrodes provided on the front side of the semiconductor substrate 120 from wiring 142. Insulating layer 141 can be made of, for example, SiO2.

[0034] The color filter 190 is an optical filter that transmits light of a predetermined wavelength among incident light. For example, a color filter that transmits red light, green light, and blue light can be used as the color filter 190 .

[0035] The on-chip lens 193 is a lens for converging incident light and is formed in, for example, a hemispherical shape, and converging the incident light onto the photoelectric conversion unit 101 .

[0036] As described above, the gate electrode 150 of the charge transfer unit 102 includes the vertical electrode portion 151. The vertical electrode portion 151 may be configured to have a refractive index lower than that of Si, which is a component constituting the semiconductor substrate 120. Therefore, the optical path length of light incident from the back surface of the semiconductor substrate 120 can be extended, and quantum efficiency can be improved.

[0037] The vertical electrode portion 151 can be formed, for example, from a transparent conductive member. Examples of such transparent conductive members include indium tin oxide (ITO), In2O3, zinc oxide (ZnO), indium zinc oxide (IZO), and indium gallium zinc oxide (IGZO). Furthermore, the vertical electrode portion 151 can also be formed from a metal, for example, aluminum (Al), gold (Au), silver (Ag), and copper (Cu).

[0038] The plate electrode portion 159 may also be configured to have a refractive index lower than the refractive index of Si constituting the semiconductor substrate 120 .

[0039] Alternatively, the flat electrode portion 159 may be formed of a member that absorbs incident light. In this case, light incident through the vertical electrode portion 151 can be absorbed by the flat electrode portion 159. This prevents the incident light from leaking to the wiring region 140.

[0040] Alternatively, the flat electrode portion 159 may be formed of a component that reflects incident light. In this case, light incident through the vertical electrode portion 151 is reflected by the flat electrode portion 159. This prevents the incident light from leaking into the wiring region 140. Furthermore, since the incident light is reflected toward the semiconductor substrate 120, the reflected light contributes to photoelectric conversion, thereby improving efficiency.

[0041] As described above, in the light detecting device 1 according to the first embodiment of the present disclosure, the refractive index of the vertical electrode portion 151 included in the gate electrode 150 of the charge transfer portion 102 is lower than that of the semiconductor substrate 120 , thereby improving photoelectric conversion efficiency.

[0042] (2. Second embodiment) The light detecting device 1 of the first embodiment described above includes a vertical electrode portion 151 whose bottom portion is configured to extend to near the back surface of the semiconductor substrate 120. On the other hand, the light detecting device 1 according to the second embodiment of the present disclosure differs from the light detecting device 1 according to the first embodiment described above in that the light detecting device 1 includes a vertical electrode portion 151 whose bottom portion reaches the back surface of the semiconductor substrate 120.

[0043] [Pixel structure] Figure 6 : is a diagram showing a configuration example of a pixel according to a second embodiment of the present disclosure. Figure 5 Similarly, this figure is a schematic cross-sectional view showing an example of the structure of the pixel 12. For convenience, the illustration of the semiconductor region and the like is omitted in the figure. The pixel 12 in the figure is Figure 5 The pixels 12 in FIG. 1 differ in the shape of the vertical electrode portion 151 .

[0044] As mentioned above, Figure 6 The vertical electrode portion 151 in the embodiment is configured in a shape such that the bottom portion reaches the back surface of the semiconductor substrate 120. Therefore, incident light can be guided by the vertical electrode portion 151.

[0045] Since the configuration of the light detecting device 1 other than this is similar to that of the light detecting device 1 in the first embodiment of the present disclosure, a description thereof will be omitted.

[0046] As described above, the light detecting device 1 according to the second embodiment of the present disclosure includes the vertical electrode portion 151 having a shape such that the bottom portion reaches the back surface of the semiconductor substrate 120. Therefore, incident light can be guided to the front surface side of the semiconductor substrate 120, and photoelectric conversion efficiency can be improved.

[0047] (3. Third embodiment) The light detecting device 1 of the first embodiment includes the vertical electrode portion 151. On the other hand, the light detecting device 1 according to the third embodiment of the present disclosure is different from the light detecting device 1 according to the first embodiment in that the light detecting device 1 includes a vertical electrode portion 151 having multiple components.

[0048] [Pixel structure] Figures 7 to 10 : is a diagram showing an example of a pixel structure according to a third embodiment of the present disclosure. Figure 5 similar, Figures 7 to 10 is a schematic cross-sectional view showing a configuration example of the pixel 12 . Figures 7 to 10 Pixel 12 and Figure 5 The difference between the pixel 12 in FIG. 1 and FIG. 2 is that the pixel 12 includes vertical electrode portions 151 and 152 .

[0049] Figure 8 An example of gate electrode 150 including vertical electrode portions 151 to 153 is shown. Vertical electrode portion 152 is provided outside vertical electrode portion 151 , and vertical electrode portion 153 is provided outside vertical electrode portion 152 .

[0050] Figure 9 An example is shown in which the vertical electrode portion 153 is arranged outside the vertical electrode portions 151 and 152 .

[0051] Figure 10 Shown Figure 9 The vertical electrode portions 151 and 153 in FIG. 1 are configured as an example of having a shape reaching the back surface of the semiconductor substrate 120 .

[0052] Since the configuration of the light detecting device 1 other than this is similar to that of the light detecting device 1 in the first embodiment of the present disclosure, a description thereof will be omitted.

[0053] As described above, in the light detecting device 1 according to the third embodiment of the present disclosure, the vertical electrode section includes a plurality of components.

[0054] (4. Modification) Deformation of the gate electrode 150 will be described.

[0055] Figures 11 to 14 is a diagram illustrating a configuration example of a pixel according to a modification example of the embodiment of the present disclosure. Figures 11 to 141 is a plan view showing an example of the configuration of pixel 12. It illustrates an example in which a plurality of vertical electrode portions 151 are arranged. By forming vertical electrode portion 151 into a shape extending in the direction of the end portion of pixel 12, the charge transfer efficiency at the end portion of pixel 12 can be improved.

[0056] Figure 15 1 is a diagram illustrating an example configuration of a pixel according to a modified example of an embodiment of the present disclosure. This diagram is a cross-sectional view illustrating an example configuration of pixel 12. The gate electrode 150 in the diagram is an example including multiple vertical electrode portions 151. This further improves charge transfer efficiency.

[0057] (5. Structure of electronic equipment) The light detection device 1 as described above can be applied to various electronic devices, such as imaging systems such as still cameras or video cameras, mobile phones with imaging functions, or other devices with imaging functions.

[0058] Figure 16 : is a block diagram showing a configuration example of an imaging device mounted on an electronic device. Figure 16 As shown, the electronic device 701 includes an optical system 702, a light detection device 703 and a digital signal processor (DSP) 704, and is constructed by connecting the DSP 704, a display device 705, an operating system 706, a memory 708, a recording device 709 and a power supply system 710 via a bus 707, and is capable of capturing still images and moving images.

[0059] The optical system 702 includes one or more lenses, guides image light (incident light) from a subject to the light detection device 703 , and forms an image on a light receiving surface (sensor portion) of the light detection device 703 .

[0060] As the light detection device 703, the light detection device 1 in any of the above-described configuration examples is applied. In the light detection device 703, electrons are accumulated for a certain period of time based on the image formed on the light receiving surface via the optical system 702. Then, a signal corresponding to the electrons accumulated in the light detection device 703 is input to the DSP 704.

[0061] The DSP 704 performs various signal processing on the signal from the light detection device 703 to acquire an image and temporarily stores the image data in the memory 708. The image data stored in the memory 708 is recorded in the recording device 709 or provided to the display device 705 for image display. In addition, the operating system 706 receives various user operations and provides operation signals to the various modules of the electronic device 701, and the power supply system 710 provides the power required to drive the various modules of the electronic device 701.

[0062] (6. Application examples of mobile objects) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be applied to a device mounted on any mobile object, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, any personal mobility device, an airplane, an unmanned aerial vehicle, a ship, and a robot.

[0063] Figure 17 : is a block diagram showing a schematic configuration example of a vehicle control system as an example of a mobile body control system to which the technology according to the embodiment of the present disclosure can be applied.

[0064] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Figure 17 In the illustrated example, a vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an exterior information detection unit 12030, an interior information detection unit 12040, and an integrated control unit 12050. Furthermore, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are illustrated as a functional configuration of the integrated control unit 12050.

[0065] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 functions as a control device for the following devices: a drive force generating device (e.g., an internal combustion engine, a drive motor, etc.) for generating vehicle drive force; a drive force transmission mechanism for transmitting drive force to wheels; a steering mechanism for adjusting the vehicle's steering angle; and a braking device for generating vehicle braking force.

[0066] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for devices such as a keyless entry system, a smart key system, power windows, and various lights such as headlights, backup lights, brake lights, turn signals, and fog lights. In this case, radio waves transmitted from a portable device serving as a key substitute or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals and controls the vehicle's door locks, power windows, lights, and the like.

[0067] The vehicle exterior information detection unit 12030 detects information about the exterior of the vehicle including the vehicle control system 12000. For example, the vehicle exterior information detection unit 12030 is connected to the imaging unit 12031. The vehicle exterior information detection unit 12030 causes the imaging unit 12031 to image the exterior of the vehicle and receive the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform processing for detecting objects such as people, vehicles, obstacles, signs, or characters on the road surface, or for detecting their distances.

[0068] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as information about the measured distance. The light received by the imaging unit 12031 can be visible light or invisible light such as infrared light.

[0069] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver status detection unit 12041 for detecting the driver's state. The driver status detection unit 12041 includes, for example, a camera for imaging the driver. Based on the detection information input from the driver status detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue or concentration, or determine whether the driver is dozing off.

[0070] The microcomputer 12051 can calculate control target values ​​for the driving force generation device, steering mechanism, or braking device based on information about the interior and exterior of the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform coordinated control to implement functions of an advanced driver assistance system (ADAS), such as collision avoidance or shock absorption of the vehicle, following driving based on vehicle spacing, speed maintenance driving, vehicle collision warning, or vehicle lane departure warning.

[0071] In addition, based on the environmental information about the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 can perform coordinated control for automatic driving by controlling the driving force generating device, steering mechanism or braking device, etc., which enables the vehicle to drive automatically without relying on the driver's operation, etc.

[0072] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the external information about the vehicle acquired by the vehicle exterior information detection unit 12030. For example, the microcomputer 12051 can perform coordinated control intended for preventing glare by, for example, controlling the headlights to switch from high beam to low beam according to the position of a preceding vehicle or an oncoming vehicle detected by the vehicle exterior information detection unit 12030.

[0073] The sound / image output unit 12052 transmits an output signal of at least one of sound and image to an output device capable of visually or auditorily notifying the vehicle occupants or the outside of the vehicle of information. Figure 17 In the example of FIG, an audio speaker 12061, a display portion 12062, and an instrument panel 12063 are shown as output devices. The display portion 12062 may include, for example, at least one of an in-vehicle display and a head-up display.

[0074] Figure 18 12031 is a diagram showing an example of the installation position of the imaging unit 12031.

[0075] exist Figure 18 , the imaging unit 12031 includes imaging units 12101 , 12102 , 12103 , 12104 and 12105 .

[0076] Imaging units 12101, 12102, 12103, 12104, and 12105 are disposed, for example, at locations such as the front nose, rearview mirror, rear bumper, rear door, and upper portion of the vehicle's windshield. Imaging unit 12101 disposed at the front nose and imaging unit 12105 disposed at the upper portion of the vehicle's windshield primarily capture images in front of vehicle 12100. Imaging units 12102 and 12103 disposed at the rearview mirror primarily capture images on both sides of vehicle 12100. Imaging unit 12104 disposed at the rear bumper or rear door primarily captures images from behind vehicle 12100. Imaging unit 12105 disposed at the upper portion of the vehicle's windshield primarily detects vehicles ahead, pedestrians, obstacles, signal lights, traffic signs, lanes, and the like.

[0077] Notice, Figure 18 Examples of the imaging ranges of imaging units 12101 to 12104 are shown. Imaging range 12111 represents the imaging range of imaging unit 12101, located at the front nose. Imaging ranges 12112 and 12113 represent the imaging ranges of imaging units 12102 and 12103, respectively, located at the rearview mirrors. Imaging range 12114 represents the imaging range of imaging unit 12104, located at the rear bumper or rear door. For example, a bird's-eye view image of vehicle 12100 is obtained by superimposing image data captured by imaging units 12101 to 12104.

[0078] At least one of the imaging units 12101 to 12104 may have a function for obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0079] For example, microcomputer 12051 can determine the distance and temporal change in distance (relative speed to vehicle 12100) of each three-dimensional object within imaging ranges 12111 to 12114 based on the distance information obtained from imaging units 12101 to 12104, and extract the closest three-dimensional object as the preceding vehicle, specifically one that is located on the travel path of vehicle 12100 and is traveling at a predetermined speed (e.g., equal to or greater than 0 km / h) in approximately the same direction as vehicle 12100. Furthermore, microcomputer 12051 can pre-set a following distance to be maintained ahead of the preceding vehicle and execute automatic braking control (including follow-stop control), automatic acceleration control (including follow-start control), and the like. Thus, coordinated control for autonomous driving can be executed, allowing the vehicle to travel automatically without relying on driver operations or the like.

[0080] For example, based on the distance information obtained from imaging units 12101 to 12104, microcomputer 12051 can classify 3D object data of 3D objects into two-wheeled vehicles, standard-sized vehicles, large vehicles, pedestrians, utility poles, and other 3D objects, extract the classified 3D object data, and use the extracted 3D object data for automatic obstacle avoidance. For example, microcomputer 12051 identifies obstacles around vehicle 12100 as those that are visually recognizable by the driver of vehicle 12100 and those that are difficult for the driver to visually recognize. Microcomputer 12051 then determines a collision risk, indicating the risk of collision with each obstacle. If the collision risk is equal to or higher than a set value, indicating a potential collision, microcomputer 12051 outputs a warning to the driver via audio speaker 12061 or display unit 12062, and the driving system control unit 12010 executes forced deceleration or evasive steering. Microcomputer 12051 can thus assist in driving to avoid collisions.

[0081] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 may identify pedestrians by determining whether a pedestrian exists in images captured by the imaging units 12101 to 12104. This pedestrian identification is performed, for example, by extracting feature points from images captured by the imaging units 12101 to 12104, which are infrared cameras, and then performing pattern matching on a series of feature points representing the object's outline to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and identifies the pedestrian, the audio / visual output unit 12052 controls the display unit 12062 to display a square outline superimposed on the identified pedestrian for emphasis. Furthermore, the audio / visual output unit 12052 may control the display unit 12062 to display an icon indicating the pedestrian at a desired location.

[0082] The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 12031 in the above configuration. Specifically, Figure 1 The light detection device 1 in the embodiment can be applied to the imaging portion 12031 .

[0083] (7. Application examples of endoscopic surgery systems) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0084] Figure 19 : is a diagram showing a schematic configuration example of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (the present technology) can be applied.

[0085] exist Figure 19 , a state is shown in which a surgical operator (doctor) 11131 is performing surgery on a patient 11132 on a bed 11133 using an endoscopic surgical system 11000. As shown in the figure, the endoscopic surgical system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm device 11120 for supporting the endoscope 11100 thereon, and a cart 11200 on which various endoscopic surgical instruments are mounted.

[0086] The endoscope 11100 includes a lens barrel 11101 and a camera 11102 connected to the proximal end of the lens barrel 11101. A region of the lens barrel 11101 having a predetermined length from its distal end is inserted into a body cavity of a patient 11132. In the illustrated example, the endoscope 11100 is shown as a rigid endoscope having a rigid lens barrel 11101. However, the endoscope 11100 may also be a flexible endoscope having a flexible lens barrel 11101.

[0087] The lens barrel 11101 has an opening at its distal end, into which the objective lens is fitted. A light source device 11203 is connected to the endoscope 11100 so that light generated by the light source device 11203 is introduced into the distal end of the lens barrel 11101 through a light guide extending inside the lens barrel 11101 and illuminates the observation target in the body cavity of the patient 11132 through the objective lens. It should be noted that the endoscope 11100 can be a forward-looking endoscope, or can be an oblique-looking endoscope or a side-looking endoscope.

[0088] The camera head 11102 is equipped with an optical system and an imaging element. The optical system focuses reflected light (observation light) from the observation target onto the imaging element. The imaging element performs photoelectric conversion on the observation light to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. This image signal is transmitted as raw data to the CCU 11201.

[0089] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), and the like, and integrally controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera 11102 and performs various image processing such as development processing (demosaic processing) on ​​the image signal to display an image based on the image signal.

[0090] Under the control of the CCU 11201 , the display device 11202 displays an image thereon based on the image signal on which the CCU 11201 has performed image processing.

[0091] The light source device 11203 includes, for example, a light source such as a light emitting diode (LED), and provides illumination light to the endoscope 11100 when imaging a surgical area.

[0092] The input device 11204 is an input interface of the endoscopic surgery system 11000. The user can input various types of information or instructions into the endoscopic surgery system 11000 through the input device 11204. For example, the user can input instructions for changing the image capturing conditions (such as the type of irradiation light, the magnification factor, and the focal length) of the endoscope 11100.

[0093] The treatment tool control device 11205 controls the driving of the energy device 11112 for burning tissue, cutting tissue, sealing blood vessels, etc. The pneumoperitoneum device 11206 feeds gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to expand the body cavity, thereby ensuring the field of view of the endoscope 11100 and ensuring the working space for the treatment operation. The recorder 11207 is a device that can record various information related to the operation. The printer 11208 is a device that can - A device that can print various information related to surgery in various forms such as text, images, and charts.

[0094] It should be noted that, for example, the light source device 11203 that provides irradiation light to the endoscope 11100 when imaging the surgical area may include a white light source, such as an LED, a laser light source, or a combination thereof. In the case where the white light source includes a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the white balance of the captured image can be adjusted by the light source device 11203. In addition, in this case, if the laser beam from the RGB laser light source is irradiated to the observation target in a time-division manner and the driving of the imaging element of the camera 11102 is controlled in synchronization with the emission timing, images corresponding to RGB respectively can be captured in a time-division manner. According to this method, a color image can be acquired even if a color filter is not provided for the imaging element.

[0095] In addition, the light source device 11203 can be controlled so that the intensity of the output light changes at predetermined intervals. By controlling the driving of the imaging element of the camera 11102 in synchronization with the timing of the change in light intensity to acquire and synthesize images in a time-division manner, a high dynamic range image without underexposed shadows and overexposed highlights can be produced.

[0096] In addition, the light source device 11203 can be configured to provide light having a predetermined wavelength region domain prepared for specific light observation. In specific light observation, for example, by utilizing the wavelength dependence of light absorption in body tissue to irradiate light having a narrower band than the irradiation light (i.e., white light) during normal observation, imaging (narrow-band imaging) of predetermined tissues such as blood vessels in the surface part of the mucosal layer with high contrast is performed. Alternatively, in specific light observation, fluorescence observation for obtaining an image based on fluorescence generated by irradiation of excitation light can be performed. In fluorescence observation, observation of fluorescence from body tissue (autofluorescence observation) can be performed by irradiating body tissue, or a fluorescence image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into body tissue and irradiating the body tissue with excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to provide narrow-band light and / or excitation light suitable for specific light observation as described above.

[0097] Figure 20 It shows Figure 19 A block diagram showing an example of the functional configuration of the camera 11102 and the CCU 11201 shown.

[0098] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are connected via a transmission cable 11400 to communicate with each other.

[0099] The lens unit 11401 is an optical system provided at a position connected to the lens barrel 11101. Observation light obtained from the distal end of the lens barrel 11101 is guided to the camera 11102 and introduced into the lens unit 11401. The lens unit 11401 includes a combination of a plurality of lenses including a zoom lens and a focus lens.

[0100] The number of imaging elements included in the imaging unit 11402 can be one (single-board type) or multiple (multi-board type). In the case where the imaging unit 11402 is constructed as a multi-board type, for example, image signals corresponding to R, G and B respectively are generated by the imaging elements, and a color image can be obtained by synthesizing these image signals. The imaging unit 11402 can also be constructed to have a pair of imaging elements for acquiring a right-eye image signal and a left-eye image signal for three-dimensional (3D) display. If 3D display is performed, the surgical operator 11131 can more accurately perceive the depth of the body tissue at the surgical site. It should be noted that in the case where the imaging unit 11402 is constructed as a multi-board type, a plurality of systems of lens units 11401 can be set in a manner corresponding to the respective imaging elements.

[0101] In addition, the imaging unit 11402 does not have to be provided in the camera head 11102. For example, the imaging unit 11402 can be provided immediately after the objective lens inside the lens barrel 11101.

[0102] The drive unit 11403 includes an actuator and, under the control of the camera control unit 11405, moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis. Therefore, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0103] 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 obtained from the imaging unit 11402 to the CCU 11201 as raw data through the transmission cable 11400.

[0104] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and provides the control signal to the camera control unit 11405. For example, the control signal includes information related to imaging conditions, such as information for specifying a frame rate for capturing an image, information for specifying an exposure value when capturing an image, and / or information for specifying a magnification and focus of a captured image.

[0105] It should be noted that image capturing conditions such as the frame rate, exposure value, magnification, and focus can be appropriately specified by the user or automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, an automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are combined in the endoscope 11100.

[0106] The camera control unit 11405 controls the driving of the camera 11102 based on a control signal received from the CCU 11201 through the communication unit 11404 .

[0107] The communication unit 11411 includes a communication device for transmitting and receiving various types of information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 through the transmission cable 11400.

[0108] In addition, the communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted through electrical communication, optical communication, or the like.

[0109] The image processing unit 11412 performs various image processing on the image signal transmitted from the camera 11102 in the form of raw data.

[0110] The control unit 11413 performs various types of control related to image capture of the surgical area, etc. performed by the endoscope 11100 and display of captured images obtained by the image capture of the surgical area, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0111] Furthermore, the control unit 11413 controls the display device 11202 to display a captured image depicting the surgical area, etc., based on the image signal processed by the image processing unit 11412. In this case, the control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, the control unit 11413 can detect the shape and color of the edges of objects included in the captured image to identify surgical tools such as forceps, specific living body parts, bleeding, and fog during the use of the energy device 11112. When the control unit 11413 controls the display device 11202 to display the captured image, it can use the recognition results to display various surgical assistance information superimposed on the image of the surgical area. Displaying and presenting this surgical assistance information to the operator 11131 in a superimposed manner can reduce the burden on the operator 11131 and enable the surgeon 11131 to perform surgery more reliably.

[0112] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 to each other is an electric signal cable for electric signal communication, an optical fiber for optical communication, or a composite cable for both electric and optical communication.

[0113] Here, in the illustrated example, although communication is performed by wired communication using the transmission cable 11400, communication between the camera head 11102 and the CCU 11201 may be performed by wireless communication.

[0114] The above describes an example of an endoscopic surgery system to which the technology of the present disclosure can be applied. The technology of the present disclosure can be applied to the imaging unit 11402 of the endoscope 11100 and the camera 11102 in the above-mentioned configuration. Specifically, Figure 1 The light detection device 1 in can be applied to the imaging unit 11402.

[0115] Although the description is given here by taking an endoscopic surgical system as an example, the technology according to the present disclosure can be applied to, for example, a microsurgery system and the like.

[0116] Note that the effects described in this specification are merely examples and are not limiting, and other effects may be provided.

[0117] Note that the present technology can also have the following configurations. (1) A light detection device comprising: a photoelectric conversion unit provided in the semiconductor substrate and performing photoelectric conversion on incident light; a charge holding portion provided in the semiconductor substrate and holding charges generated by the photoelectric conversion; and A charge transfer portion is provided in the semiconductor substrate and is configured by a MOS transistor and is configured to transfer the charge of the photoelectric conversion portion to the charge holding portion, wherein the MOS transistor includes a gate electrode having a vertical electrode portion configured in a shape such that the bottom portion extends to the vicinity of the back surface of the semiconductor substrate and is configured to have a refractive index lower than the refractive index of the semiconductor substrate. (2) The photodetection device according to (1) above, wherein the vertical electrode portion has a shape in which a bottom portion reaches the back surface of the semiconductor substrate. (3) The photodetection device according to (1) or (2) above, wherein the vertical electrode portion is formed of a transparent conductive member. (4) The photodetection device according to (1) or (2) above, wherein the vertical electrode portion is made of metal. (5) The photodetection device according to any one of (1) to (4) above, wherein the vertical electrode portion includes a plurality of components. (6) A light detection device according to any one of (1) to (5) above, wherein the gate electrode further includes a flat electrode portion, the flat electrode portion is arranged on the front side of the semiconductor substrate, and the bottom of the flat electrode portion is in contact with the vertical electrode portion. (7) The light detection device according to (6) above, wherein the refractive index of the planar electrode portion is lower than the refractive index of the semiconductor substrate. (8) The photodetection device according to (6) above, wherein the planar electrode portion includes a member that reflects the incident light. (9) The light detection device according to (6) above, wherein the planar electrode portion includes a member that absorbs the incident light. (10) The photodetection device according to any one of (1) to (9) above, wherein the gate electrode includes a plurality of the vertical electrode portions. (11) An electronic device comprising: a photoelectric conversion unit provided in the semiconductor substrate and performing photoelectric conversion on incident light; a charge holding portion provided in the semiconductor substrate and holding the charge generated by the photoelectric conversion; a charge transfer portion provided in the semiconductor substrate and configured by a MOS transistor and configured to transfer the charge of the photoelectric conversion portion to the charge holding portion, the MOS transistor including a gate electrode having a vertical electrode portion configured such that a bottom portion extends to the vicinity of a back surface of the semiconductor substrate and configured to have a refractive index lower than that of the semiconductor substrate; and A processing circuit processes a signal based on the charge held in the charge holding portion. Reference Signs List

[0118] 1.703 optical detection device 12 pixels 34 columns of signal processing circuits 101 Photoelectric Conversion Unit 102 Charge Transfer Unit 103 Charge retention unit 120 semiconductor substrate 150 Gate electrode 151 to 153 vertical electrode portion 159 flat electrode part 701 Electronic Equipment 11402, 12031, 12101 to 12105 Imaging Department

Claims

1. A light detection device, comprising: a photoelectric conversion unit provided in the semiconductor substrate and performing photoelectric conversion on incident light; a charge holding portion provided in the semiconductor substrate and holding the charge generated by the photoelectric conversion; as well as A charge transfer portion is provided in the semiconductor substrate and is configured by a MOS transistor and is configured to transfer the charge of the photoelectric conversion portion to the charge holding portion, wherein the MOS transistor includes a gate electrode having a vertical electrode portion configured in a shape such that the bottom portion extends to the vicinity of the back surface of the semiconductor substrate and is configured to have a refractive index lower than the refractive index of the semiconductor substrate.

2. The light detection device according to claim 1, wherein The vertical electrode portion has a shape such that its bottom reaches the back surface of the semiconductor substrate.

3. The light detection device according to claim 1, wherein The vertical electrode portion is formed of a transparent conductive member.

4. The light detection device according to claim 1, wherein The vertical electrode portion is made of metal.

5. The light detection device according to claim 1, wherein The vertical electrode portion includes a plurality of components. The light detection device according to claim 1 , wherein: The gate electrode further includes a flat plate electrode portion provided on the front surface side of the semiconductor substrate, and a bottom portion of the flat plate electrode portion is in contact with the vertical electrode portion.

7. The light detection device according to claim 6, wherein The refractive index of the plate electrode portion is lower than the refractive index of the semiconductor substrate.

8. The light detection device according to claim 6, wherein The flat electrode portion includes a member that reflects the incident light.

9. The light detection device according to claim 6, wherein The flat electrode portion includes a component that absorbs the incident light.

10. The light detection device according to claim 1, wherein The gate electrode includes a plurality of the vertical electrode portions.

11. An electronic device comprising: a photoelectric conversion unit provided in the semiconductor substrate and performing photoelectric conversion on incident light; a charge holding portion provided in the semiconductor substrate and holding the charge generated by the photoelectric conversion; a charge transfer portion provided in the semiconductor substrate and configured by a MOS transistor and configured to transfer the charge of the photoelectric conversion portion to the charge holding portion, the MOS transistor including a gate electrode having a vertical electrode portion configured such that a bottom portion extends to the vicinity of a back surface of the semiconductor substrate and configured to have a refractive index lower than that of the semiconductor substrate; as well as A processing circuit processes a signal based on the charge held in the charge holding portion.

Images