Photodetector and semiconductor device

Abstract

To provide a photodetector and a semiconductor device that can reduce the area of an element, effectively suppress or prevent noise generation, and further simplify the structure of a carrier transfer path.SOLUTION: A photodetector includes: a photoelectric conversion element that converts light into an electric charge; a floating diffusion that is disposed at a distance from the photoelectric conversion element in a first direction; and a transistor that electrically connects the photoelectric conversion element and the floating diffusion. The transistor is disposed between the photoelectric conversion element and the floating diffusion, and includes: a channel formation region that is disposed overlapping the floating diffusion when viewed from the first direction; and a gate electrode disposed between the photoelectric conversion element and the floating diffusion and disposed in the channel formation region via a gate insulating film.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a photodetector and a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a solid-state imaging device, in which a photoelectric conversion element is electrically connected to a floating diffusion through a vertical transfer transistor.

[0003] The photoelectric conversion element is composed of a photodiode formed inside a semiconductor substrate. The vertical transfer transistor has a gate electrode formed in the depth direction (vertical direction) of the semiconductor substrate from the surface of the semiconductor substrate to the photoelectric conversion element. One main electrode of the vertical transfer transistor is the cathode region of the photoelectric conversion element, and the other main electrode is a floating diffusion. A channel is formed near the interface of the semiconductor substrate with a gate insulating film interposed along the gate electrode. The gate electrode is also drawn out horizontally above the surface of the semiconductor substrate and is electrically connected to wiring. The floating diffusion is formed in a surface portion of the semiconductor substrate in a region separate from the gate electrode and its lead-out portion, and is made of an n-type semiconductor region. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-114274 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the solid-state imaging device disclosed in the above-mentioned Patent Document 1, the gate electrode and its lead-out portion, and the floating diffusion are formed in separate regions on the surface of the semiconductor substrate, which increases the area of ​​the pixel. In the solid-state imaging device, a channel is formed in the vertical transfer transistor near the interface of the semiconductor substrate along the gate electrode, and therefore carrier trapping or detrapping due to crystal defects occurs near the interface of the semiconductor substrate, which tends to generate noise. Furthermore, in the above solid-state imaging device, carriers (charges) converted from light by the photoelectric conversion element are transferred vertically through the vertical transfer transistor, and the transferred carriers are transferred horizontally to the floating diffusion. This complicates the energy potential structure for transferring the carriers. In the manufacturing method of the solid-state imaging device, the number of times of implanting impurities to form the energy potential structure increases.

[0006] Therefore, there has been a demand for a photodetector and a semiconductor device that can reduce the area of ​​the element, effectively suppress or prevent the generation of noise, and further simplify the structure of the carrier transfer path. [Means for solving the problem]

[0007] The photodetection device according to the first embodiment of the present disclosure comprises a photoelectric conversion element that converts light into an electric charge, a floating diffusion arranged spaced apart from the photoelectric conversion element in a first direction, and a transistor that electrically connects the photoelectric conversion element and the floating diffusion, the transistor comprising a channel formation region arranged between the photoelectric conversion element and the floating diffusion and overlapping the floating diffusion when viewed from the first direction, and a gate electrode arranged between the photoelectric conversion element and the floating diffusion and in the channel formation region with a gate insulating film interposed therebetween.

[0008] A photodetector according to a second embodiment of the present disclosure is the photodetector according to the first embodiment, in which an insulator is disposed on a side of the gate electrode in a first direction along the periphery of the side of the floating diffusion.

[0009] A photodetection device according to a third embodiment of the present disclosure includes a photoelectric conversion element that converts light into an electric charge, a first transistor having a first channel formation region, one end of the first channel formation region electrically connected to the photoelectric conversion element and the other end of the first channel formation region extending in a first direction away from the photoelectric conversion element, a floating diffusion having one end electrically connected to the other end of the first channel formation region and the other end extending in the first direction, and a second transistor having a second channel formation region, one end of the second channel formation region electrically connected to the other end of the floating diffusion, and the other end of the second channel formation region extending in the first direction.

[0010] A photodetector according to a fourth embodiment of the present disclosure is the photodetector according to the third embodiment, further comprising a third transistor arranged in a second direction intersecting the first direction and spaced apart from the first channel formation region, the third transistor having a third channel formation region extending in the first direction, and a fourth transistor arranged in a second direction and spaced apart from the second channel formation region, electrically connected to the third channel formation region, and the fourth transistor having a fourth channel formation region extending in the first direction. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic system configuration diagram of a photodetector according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic exploded plan view of the photodetector shown in FIG. [Diagram 3] FIG. 3 is a circuit configuration diagram of the pixel and pixel circuit of the photodetector shown in FIG. [Figure 4] FIG. 4 is a cross-sectional configuration diagram of the pixel and pixel circuit of the photodetector shown in FIG. 1 (a cross-sectional view taken along the line AA shown in FIG. 5). [Diagram 5] FIG. 5 is a plan view showing a part of a pixel and a pixel circuit of the photodetector shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view illustrating a first step in the method for manufacturing the photodetector according to the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view of the second step. [Figure 8] FIG. 8 is a cross-sectional view of the third step. [Figure 9] FIG. 9 is a cross-sectional view of the fourth step. [Figure 10] FIG. 10 is a cross-sectional view of the fifth step. [Figure 11] FIG. 11 is a cross-sectional view of the sixth step. [Figure 12] FIG. 12 is a cross-sectional view of the seventh step. [Figure 13] FIG. 13 is a cross-sectional view of the eighth step. [Figure 14] FIG. 14 is a cross-sectional view illustrating a first step in a manufacturing method for a photodetector according to the second embodiment of the present disclosure. [Figure 15] FIG. 15 is a cross-sectional view of the second step. [Figure 16] FIG. 16 is a cross-sectional view of the third step. [Figure 17] FIG. 17 is a cross-sectional view of the fourth step. [Figure 18] FIG. 18 is a cross-sectional view of the fifth step. [Figure 19] FIG. 19 is a cross-sectional view of the sixth step. [Figure 20] FIG. 20 is a cross-sectional view of the seventh step. [Figure 21] FIG. 21 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to a third embodiment of the present disclosure. [Figure 22] FIG. 22 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to a fourth embodiment of the present disclosure. [Diagram 23] FIG. 23 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to a fifth embodiment of the present disclosure. [Figure 24]FIG. 24 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to the sixth embodiment of the present disclosure. [Diagram 25] FIG. 25 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to the seventh embodiment of the present disclosure. [Figure 26] FIG. 26 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to the eighth embodiment of the present disclosure. [Figure 27] FIG. 27 is a plan configuration diagram of a main portion of a pixel and a pixel circuit of a photodetector according to a ninth embodiment of the present disclosure. [Figure 28] FIG. 28 is a cross-sectional configuration diagram (a cross-sectional view taken along line BB shown in FIG. 29) of a pixel and a pixel circuit of a photodetector according to a tenth embodiment of the present disclosure. [Figure 29] FIG. 29 is a plan view showing the configuration of a pixel circuit of the photodetector shown in FIG. [Diagram 30] FIG. 30 is a cross-sectional configuration diagram (a cross-sectional view taken along line CC shown in FIG. 31) of a pixel and a pixel circuit of a photodetector according to an eleventh embodiment of the present disclosure. [Diagram 31] FIG. 31 is a plan view showing the configuration of a pixel circuit of the photodetector shown in FIG. [Diagram 32] FIG. 32 is a block diagram showing a configuration of an electronic device according to a twelfth embodiment of the present disclosure. [Diagram 33] FIG. 33 is a block diagram showing an example of a schematic configuration of a vehicle control system. [Diagram 34] FIG. 34 is an explanatory diagram showing an example of the installation positions of the vehicle outside information detection unit and the imaging unit. [Diagram 35] FIG. 35 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. [Diagram 36] FIG. 36 is a block diagram showing an example of a functional configuration of the camera head and the CCU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. First embodiment The first embodiment describes a first example in which the present technology is applied to a photodetector. The first embodiment describes the overall configuration of the photodetector, the configuration of a pixel, and the configuration of a pixel circuit. Furthermore, the first embodiment describes a manufacturing method of the photodetector. 2. Second embodiment The second embodiment describes a second example of the photodetector according to the first embodiment, in which the manufacturing method is changed. 3. Third embodiment The third embodiment describes a third example in which the structure of the transistors and floating diffusion that constitute the pixels in the photodetector according to the first or second embodiment is changed. 4. Fourth embodiment The fourth embodiment describes a fourth example in which the structure of the transistors and floating diffusion that constitute the pixels in the photodetector according to the first or second embodiment is changed. 5. Fifth embodiment The fifth embodiment describes a fifth example of the photodetector according to the fourth embodiment, in which the structures of the transistors and floating diffusion that constitute the pixels are changed. 6. Sixth embodiment The sixth embodiment describes a sixth example of the photodetector according to the third embodiment, in which the structures of the transistors and floating diffusion that constitute the pixels are changed. 7. Seventh embodiment The seventh embodiment describes a seventh example in which the structures of the transistors and floating diffusion that constitute the pixels in the photodetector according to the sixth embodiment are changed. 8. Eighth embodiment The eighth embodiment describes an eighth example of the photodetector according to the third embodiment, in which the structures of the transistors and floating diffusion that constitute the pixels are changed. 9. Ninth embodiment The ninth embodiment describes a ninth example in which the structures of the transistors and floating diffusion that constitute the pixels in the photodetector according to the eighth embodiment are changed. 10. Tenth embodiment The tenth embodiment describes a tenth example in which a phase difference detection pixel is constructed in the photodetection device according to the first or second embodiment. 11. Eleventh embodiment The eleventh embodiment describes an eleventh example in which the structure of transistors that configure pixels and pixel circuits in the photodetector according to the tenth embodiment is changed. 12. Twelfth embodiment The twelfth embodiment describes a twelfth example in which the present technology is applied to an electronic device including a photodetector according to any one of the first to eleventh embodiments. 13. Mobile application examples In this application example, an example in which the present technology is applied to a vehicle control system, which is an example of a mobile body control system, will be described. 14. Application example to endoscopic surgery system This application example describes an example in which the present technology is applied to an endoscopic surgery system. 15. Other embodiments

[0013] <1. First embodiment> A photodetector 1 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 13. FIG.

[0014] Here, the arrow X direction shown in the drawings indicates one planar direction of the photodetector 1 placed on a flat surface for the sake of convenience. The arrow Y direction indicates another planar direction perpendicular to the arrow X direction. The arrow Z direction indicates the upward direction perpendicular to the arrow X and arrow Y directions. In other words, the arrow X direction, arrow Y direction, and arrow Z direction exactly coincide with the X-axis direction, Y-axis direction, and Z-axis direction, respectively, of a three-dimensional coordinate system. Note that these directions are shown for the sake of convenience in order to facilitate understanding of the description, and are not intended to limit the directions of the present technology.

[0015] [Configuration of photodetector 1] (1) Overall configuration of the photodetector 1 1 shows an example of a system configuration of a photodetector 1 according to the first embodiment. Here, the photodetector 1 is constructed as a CMOS (Complementary Metal Oxide Semiconductor) type solid-state imaging device. In the solid-state imaging device, light L (see FIG. 4) incident from the outside is detected, the detected light L is converted into electric charges, and an image such as a still image or a moving image is generated based on the converted electric charges.

[0016] The photodetector 1 includes a pixel region (pixel array portion) 100 having a plurality of pixels 10 regularly arranged two-dimensionally within a plane in the directions of the arrows X and Y, and peripheral circuits.

[0017] As will be described later, the pixel 10 includes a photoelectric conversion element PD (see FIG. 3) and a transfer transistor TR (see FIG. 3). The photoelectric conversion element PD is formed of, for example, a photodiode. The photoelectric conversion element PD converts light L into electric charges. The transfer transistor TR transfers the electric charges converted by the photoelectric conversion element PD. In addition, a pixel circuit 20 (see FIG. 3) is electrically connected to the pixel 10. In the pixel circuit 20, the charge converted in the pixel 10 is read out.

[0018] The peripheral circuits are constructed to include a vertical drive circuit VD, a column signal processing circuit CS, a horizontal drive circuit HD, an output circuit Out, and a control circuit CC.

[0019] The control circuit CC receives an input clock and data instructing the operation mode etc., and outputs data such as internal information of the photodetector 1. That is, the control circuit CC generates clock signals and control signals that serve as the reference for the operation of the vertical drive circuit VD, the column signal processing circuit CS, the horizontal drive circuit HD etc., based on a vertical synchronizing signal, a horizontal synchronizing signal and a master clock. These signals are then input to the vertical drive circuit VD, the column signal processing circuit CS, the horizontal drive circuit HD etc.

[0020] The vertical drive circuit VD is composed of, for example, a shift register. The vertical drive circuit VD selects a pixel drive line Ld and supplies a pulse for driving the pixel 10 to the selected pixel drive line. The pixels 10 are driven row by row. That is, the vertical drive circuit VD sequentially selects and scans each pixel 10 in the pixel region 100 in the vertical direction row by row. A signal charge generated in the photoelectric conversion element of each pixel 10 according to the amount of light received is supplied to the column signal processing circuit CS as a pixel signal through the vertical signal line Lv.

[0021] The column signal processing circuit CS is arranged, for example, for each column of the pixels 10. In the column signal processing circuit CS, signal processing such as noise removal is performed for each pixel column on signals output from one row of the pixels 10. That is, the column signal processing circuit CS performs signal processing such as CDS (Correlated Double Sampling) for removing fixed pattern noise specific to the pixels 10, signal amplification, AD (Analog-to-Digital) conversion, etc. At the output stage of the column signal processing circuit CS, a horizontal selection switch (not shown) is connected between the output stage and the horizontal signal line Lh.

[0022] The horizontal driving circuit HD is formed of, for example, a shift register. The horizontal driving circuit HD sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits CS in turn, and outputs pixel signals from each of the column signal processing circuits CS to the horizontal signal line Lh.

[0023] The output circuit Out processes and outputs signals sequentially supplied from each of the column signal processing circuits CS through the horizontal signal line Lh. For example, the output circuit Out may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal In exchanges signals between the photodetector 1 and the outside.

[0024] (2) Configuration of the photodetector 1 FIG. 2 shows an example of a schematic exploded planar configuration of the photodetector 1 shown in FIG. The light detection device 1 has a three-layer structure in which a first substrate 1A, a second substrate 1B, and a third substrate 1C are stacked and bonded together. Here, the third substrate 1C, the second substrate 1B, and the first substrate 1A are stacked in this order in the direction of the arrow Z. In the first to twelfth embodiments, an example will be described in which the present technology is applied to a photodetector 1 having a two-layer structure in which a first base 1A and a second base 1B are one base. Of course, the photodetector 1 according to the first to twelfth embodiments may be configured with a three-layer structure.

[0025] The first base 1A is formed in a rectangular shape when viewed from the direction of the arrow Z (hereinafter simply referred to as "in a plan view"). To explain in detail, the first base 1A is formed in a square shape here. The first base 1A includes a semiconductor substrate made of, for example, single crystal silicon. A photoelectric conversion element PD and a transfer transistor TR constituting a pixel 10 are disposed on the semiconductor substrate of the first base body 1A. A pixel region 100 is disposed over substantially the entire area of ​​the first base body 1A. As described above, a plurality of pixels 10 are arranged in the pixel region 100. In other words, the first base body 1A constitutes a light detection surface as an imaging surface for capturing an image. Here, the arrow Z direction or the opposite direction corresponds to the "first direction" according to the present technology. Furthermore, the arrow X direction or the opposite direction, and the arrow Y direction or the opposite direction correspond to the "second direction" according to the present technology.

[0026] The second base 1B is formed in a rectangular shape in plan view similar to that of the first base 1A, and is formed to have a planar size similar to that of the first base 1A. The second base 1B includes a semiconductor substrate made of, for example, single crystal silicon, similar to the first base 1A. A plurality of transistors constituting a pixel circuit 20 (not shown here) are arranged on the semiconductor substrate of the second base 1B. In particular, the number of transistors arranged is not limited, but in the first embodiment, one pixel circuit 20 is arranged for four pixels 10. The plurality of transistors constituting the pixel circuit 20 will be described later. The second base 1B is also provided with pixel drive wiring Ld that overlaps the pixel region 100 in a plan view and extends through the pixel region 100 in the X direction and vertical signal lines Lv that extend in the Y direction. In the case of a photodetector 1 having a two-layer structure, the pixel circuit 20 is disposed on a substrate that combines the first substrate 1A and the second substrate 1B into one substrate.

[0027] The third base 1C is formed in a rectangular shape in plan view similar to that of the first base 1A, and is formed to have a planar size similar to that of the first base 1A. The third base 1C includes a semiconductor substrate made of, for example, single crystal silicon, similar to the first base 1A. Peripheral circuits are disposed on the semiconductor substrate of the third base body 1C, and as described above, the peripheral circuits include the vertical drive circuit VD, the column signal processing circuit CS, the horizontal drive circuit HD, the output circuit Out, and the control circuit CC.

[0028] In the first embodiment, each circuit of the peripheral circuit is a logic circuit. The logic circuit is constructed to include one or more semiconductor elements selected from a transistor, a capacitor, and a resistor. An insulated gate field effect transistor (IGFET) is used as the transistor. A low resistance layer formed by using a salicide (self-aligned silicide) process of CoSi2, NiSi, or the like is formed on the surface of at least a pair of main electrodes of the transistor. For example, the resistance value of the low resistance layer is smaller than the resistance value of the semiconductor layer.

[0029] (3) Circuit configuration of pixel 10 and pixel circuit 20 FIG. 3 shows an example of a circuit configuration of the pixel 10 and the pixel circuit 20 of the photodetector 1. As shown in FIG. In the first embodiment, four pixels 10 are electrically connected to one pixel circuit 20, and the four pixels 10 share one pixel circuit 20. That is, the electric charges converted from the light L in each of the four pixels 10 are read out in the one pixel circuit 20.

[0030] The pixel 10 includes a photoelectric conversion element PD and a transfer transistor TR, and is configured as a series circuit of the two. More specifically, the photoelectric conversion element PD is constituted by a photodiode, which has an anode region and a cathode region. On the other hand, the transfer transistor TR is an IGFET, which includes a pair of main electrodes (a source region and a drain region) and a gate electrode. The anode region of the photoelectric conversion element PD is electrically connected to a reference voltage GND, and the cathode region is electrically connected to one of the main electrodes of the transfer transistor TR. The other main electrode of the transfer transistor TR is electrically connected to one end of the floating diffusion FD. A control signal for controlling the conduction or non-conduction is input to the gate electrode.

[0031] As described above, four pixels 10 are arranged for one pixel circuit 20, and therefore, the identification numbers 1, 2, 3, or 4 are added to the end of the reference numerals of the components within the pixel 10 to distinguish them from one another. For example, one of the four pixels 10 is configured to include a photoelectric conversion element PD1 and a transfer transistor TR1. In addition, when there is no need to distinguish between them, no identification number is given.

[0032] The pixel circuit 20 is here constructed with a reset transistor RST, an amplification transistor AMP and a selection transistor SEL, which are IGFETs.

[0033] One main electrode of the reset transistor RST is electrically connected to the other end of the floating diffusion FD, and the other main electrode is electrically connected to a power supply voltage VDD. A reset signal is input to the gate electrode. When the reset transistor RST becomes conductive, it resets the floating diffusion FD to a potential equivalent to the power supply voltage VDD.

[0034] One main electrode of the amplification transistor AMP is electrically connected to one main electrode of the selection transistor SEL, and the other main electrode is electrically connected to a power supply voltage VDD. One main electrode of the reset transistor RST and the other end of the floating diffusion FD are electrically connected to the gate electrode. The amplifier transistor AMP constitutes a source follower type amplifier. In other words, the amplifier transistor AMP generates a pixel signal according to the charge transferred through the floating diffusion FD.

[0035] The other main electrode of the selection transistor SEL is electrically connected to the vertical signal line Lv. A selection signal is input to the gate electrode. The selection transistor SEL outputs the generated pixel signal to a vertical signal line Lv.

[0036] (4) Device configuration of pixel 10 and pixel circuit 20 Fig. 4 shows an example of a cross-sectional configuration of the pixel 10 and the pixel circuit 20 of the photodetector 1. Fig. 5 shows an example of a planar configuration of a part of the pixel 10 and the pixel circuit 20. As described above, the photodetector 1 according to the first embodiment employs a two-layer structure in which the first base 1A and the second base 1B are combined into one base, and further includes a third base 1C. For this reason, the pixels 10 and the pixel circuits 20 are disposed on the semiconductor substrate 30 which forms one base corresponding to the first base 1A and the second base 1B.

[0037] (4-1) Photoelectric conversion element PD device configuration Although detailed structural illustration and description are omitted, the photoelectric conversion element PD is disposed inside the semiconductor substrate 30 in a region surrounded by the pixel isolation region 31 in the directions of the arrows X and Y. In other words, the pixel 10 is constructed in the region surrounded by the pixel isolation region 31.

[0038] The pixel isolation region 31 includes a groove 311 and a filling material 312. The groove 311 is formed by digging down in the thickness direction of the semiconductor substrate 30 from a surface 30A of the semiconductor substrate 30 toward another surface 30B opposite to the surface 30A. The grooves 311 extend in the direction of the arrow X and are disposed at regular intervals in the direction of the arrow Y, and also extend in the direction of the arrow Y and are disposed at regular intervals in the direction of the arrow X. That is, the grooves 311 are formed in a lattice shape in a plan view. Therefore, in the first embodiment, the planar shape of the pixel 10 is formed in a rectangular shape in a plan view. More specifically, in the first embodiment, the planar shape of the pixel 10 is formed in a square shape. The filler 312 fills the grooves 311. The filler 312 is made of an insulating material such as SiO2 that can optically and electrically separate adjacent pixels 10. Note that the pixel isolation region 31 is merely an example and is not limited to the structure shown in Fig. 4. For example, the groove 311 may be formed by digging down in the thickness direction of the semiconductor substrate 30 from the surface 30B toward the surface 30A of the semiconductor substrate 30. The pixel isolation region 31 may also be formed by combining shallow grooves and deep grooves.

[0039] The photoelectric conversion element PD includes a p-type semiconductor region 30p as an anode region, and an n-type semiconductor region 30n as a cathode region. In addition, in a surface portion of the p-type semiconductor region 30p along the pixel isolation region 31, a pinning region (not shown) having a higher impurity density than the p-type semiconductor region 30p and the same conductivity type is disposed.

[0040] A floating diffusion FD is disposed on the front surface 30B side of the semiconductor substrate 30. The floating diffusion FD is disposed away from the photoelectric conversion element PD in the direction opposite to the arrow Z direction. Furthermore, the floating diffusion FD is disposed in the center of the pixel 10 in a plan view. That is, the floating diffusion FD is disposed in the photoelectric conversion element PD at a position overlapping with the photoelectric conversion element PD. Here, the planar shape of the floating diffusion FD is formed in a circular shape. The floating diffusion FD is formed by, for example, an n-type semiconductor region 50.

[0041] (4-2) Device configuration of transfer transistor TR The transfer transistor TR is disposed in the pixel 10 and in the photoelectric conversion element PD when viewed from the direction of the arrow Z or the opposite direction. The transfer transistor TR includes a channel formation region 40, a gate insulating film 42, a gate electrode 43, and a pair of main electrodes (a source region and a drain region) as main components.

[0042] The channel formation region 40 of the transfer transistor TR is disposed between the photoelectric conversion element PD and the floating diffusion FD, and is disposed so as to overlap the floating diffusion FD when viewed from the direction of the arrow Z (first direction). The channel formation region 40 is formed in a cylindrical shape with a height from the photoelectric conversion element PD to the floating diffusion FD. The channel formation region 40 utilizes a part of the semiconductor substrate 30 and is formed of a p-type semiconductor region. In addition, the term "overlap" is used to mean both partial overlap and complete overlap. Furthermore, the term "cylindrical shape" refers to one form of a column.

[0043] The gate electrode 43 is disposed in the photoelectric conversion element PD in a plan view, and is disposed between the photoelectric conversion element PD and the floating diffusion FD. In other words, in a plan view, the planar area of ​​the gate electrode 43 is smaller than the planar area of ​​the photoelectric conversion element PD, and the entire gate electrode 43 is configured to overlap the photoelectric conversion element PD. The gate electrode 43 extends in the thickness direction (arrow Z direction) of the semiconductor substrate 30 along the channel formation region 40, and has a vertical gate structure. In the first embodiment, the gate electrode 43 is disposed so as to effectively surround the entire side periphery of the cylindrical channel formation region 40. The gate electrode 43 is formed in a circular ring shape in a plan view. A part of the gate electrode 43 is extended to the front surface 30B of the semiconductor substrate 30 and formed as a connection region with wiring (not shown). The gate electrode 43 is made of a gate electrode material such as polycrystalline silicon.

[0044] A gate insulating film 42 is disposed between the channel forming region 40 and the gate electrode 43. The gate insulating film 42 is made of a gate insulating film material such as SiO2.

[0045] One main electrode of the transfer transistor TR is formed by the cathode region of the photoelectric conversion element PD, and the other main electrode is formed by the floating diffusion FD. Here, the transfer transistor TR corresponds to a "transistor" or a "first transistor" according to the present technology.

[0046] In the transfer transistor TR configured in this manner, an insulator 6 is disposed on the side opposite to the direction of the arrow Z of the gate electrode 43, that is, on the side surface 30B side of the semiconductor substrate 30. The insulator 6 is disposed along the periphery of the side surface of the floating diffusion FD. The insulator 6 is made of an insulating material such as SiO2. Furthermore, the thickness of the insulator 6 in the direction of the arrow Z is greater than the thickness (thickness in the second direction) of the gate insulating film 42 from the channel formation region 40 to the gate electrode 43. The thickness of the insulator 6 is, for example, 20 nm or more. A part of the insulator 6 may be replaced with a p-type semiconductor region that can provide insulation and isolation from the floating diffusion FD.

[0047] (4-3) Device configuration of reset transistor RST The reset transistor RST is disposed in the pixel 10 on the opposite side of the transfer transistor TR in the direction of the arrow X. The reset transistor RST is disposed in a surface 30B portion of the semiconductor substrate 30. The reset transistor RST includes, as main components, a channel formation region (not shown), a gate insulating film 52, a gate electrode 53, and a pair of main electrodes. The channel formation region of the reset transistor RST is a p-type semiconductor region in the surface 30B portion of the semiconductor substrate 30. A gate electrode 53 is disposed in the channel formation region with a gate insulating film 52 interposed therebetween. A pair of main electrodes is formed of an n-type semiconductor region 50. The n-type semiconductor region 50 that is the main electrode and the n-type semiconductor region 50 that is the floating diffusion FD are each formed by the same manufacturing process.

[0048] (4-4) Device configuration of the amplifier transistor AMP The amplification transistor AMP is disposed on the direction of the arrow X with respect to the transfer transistor TR within the pixel 10. The amplification transistor AMP is disposed on the surface 30B of the semiconductor substrate 30, similar to the reset transistor RST. Like the reset transistor RST, the amplification transistor AMP includes, as main components, a channel formation region (not shown), a gate insulating film 52, a gate electrode 53, and a pair of main electrodes.

[0049] (4-4) Device configuration of selection transistor SEL The selection transistor SEL is disposed on the direction of the arrow X with respect to the transfer transistor TR within the pixel 10. The selection transistor SEL is disposed on the surface 30B of the semiconductor substrate 30, similar to the reset transistor RST. Like the reset transistor RST, the selection transistor SEL includes, as main components, a channel formation region (not shown), a gate insulating film 52, a gate electrode 53, and a pair of main electrodes. Moreover, the n-type semiconductor region 50 which is one of the main electrodes of the selection transistor SEL is formed integrally with the n-type semiconductor region 50 which is one of the main electrodes of the amplification transistor AMP, and is shared.

[0050] (5) Configuration of Optical Filter 8 In the pixel 10, an optical filter 8 and an optical lens 9 are sequentially disposed on a surface 30A of a semiconductor substrate 30 with a protective film 7 interposed therebetween. The optical filter 8 is formed, for example, as a red color filter that transmits light L in the red light band, a green color filter that transmits light L in the green light band, or a blue color filter that transmits light L in the blue light band. The optical filter 8 may be a filter that transmits near-infrared light. The optical filter 8 is made of, for example, a resin material to which an organic pigment is added. As the resin material, an acrylic resin, a styrene resin, or the like can be used.

[0051] (6) Configuration of Optical Lens 9 The optical lenses 9 are disposed for each pixel 10 or for each set of pixels 10 when viewed in the direction of the arrow Y (hereinafter simply referred to as "when viewed from the side"). When viewed from the side, the optical lenses 9 are formed in a curved shape that protrudes in the direction of the arrow Z. The optical lenses 9 are formed, for example, from a resin material having optical transparency. Although not shown in the drawings or in a detailed description, the optical lenses 9 may be formed with an anti-reflection film. The optical lenses 9 are connected to adjacent other optical lenses 9, and the plurality of optical lenses 9 are integrally formed. The optical lenses 9 are configured as on-chip lenses.

[0052] Incidentally, illustration and detailed description of the peripheral circuits disposed on the third substrate 1C of the photodetector 1 will be omitted.

[0053] [Method of manufacturing the photodetector 1] 6 to 13 show an example of process cross sections for explaining each step of the method for manufacturing the photodetector 1. FIG. The method for manufacturing the photodetector 1 according to the first embodiment is mainly a method for manufacturing the transfer transistor TR of the pixel 10. The method for manufacturing the photodetector 1 is as follows. First, a semiconductor substrate 30 is prepared as shown in Fig. 6. This semiconductor substrate 30 is in the state of a semiconductor wafer before a dicing process, and has a pixel isolation region 31 and a photoelectric conversion element PD formed therein.

[0054] Next, a mask 301 and a mask 302 are sequentially formed on the surface 30B of the semiconductor substrate 30. The mask 301 is made of, for example, SiO2, and the mask 302 is made of, for example, SiN. The masks 301 and 302 have openings in regions where the gate electrodes 43 of the transfer transistors TR are to be formed (see FIG. 7). 7, a groove 303 is formed from the surface 30B of the semiconductor substrate 30 to the photoelectric conversion element PD using a mask 301 and a mask 302. Anisotropic etching such as RIE (Reactive Ion Etching) is used to form the groove 303. When the groove 303 is formed, a cylindrical channel formation region 40 of the transfer transistor TR is formed.

[0055] 8, a gate insulating film 42 is formed along the side and bottom surfaces of the trench 303, i.e., at least the side surfaces of the channel formation region 40. The gate insulating film 42 is formed by using, for example, a thermal oxidation method, and is made of SiO2 here.

[0056] 9, a gate electrode material 43A is buried in the trench 303 with a gate insulating film 42 interposed therebetween. The gate electrode material 43A is formed, for example, by using a CVD (Chemical Vapor Deposition) method, and is made of polycrystalline silicon here. Excess gate electrode material 43A on the mask 302 is removed by a planarization process. For example, a CMP (Chemical Mechanical Polishing) method or an etch-back method is used for the planarization process.

[0057] 10, the gate electrode material 43A is patterned to expose a part of the groove 303. The patterning is performed by an etching method using a mask (not shown) formed by photolithography.

[0058] 11, an insulator 60 is embedded in a part of the exposed groove 303. The insulator 60 is formed by using, for example, a CVD method or a sputtering method, and is formed of SiO2 here.

[0059] 12, a part of the gate electrode material 43A is removed on the front surface 30B side of the semiconductor substrate 30. The amount of the gate electrode material 43A removed corresponds to the depth of the floating diffusion FD (n-type semiconductor region 50) in the direction of the arrow Z. In this step, the gate electrode 43 of the transfer transistor TR is substantially completed.

[0060] 13, an insulator 6 is formed in the region where a portion of the gate electrode material 43A has been removed. The insulator 6 is formed, for example, by a CVD method or a sputtering method, and is formed of SiO2 here. Excess insulator 6 is removed by a planarization process, for example, by a CMP method or an etch-back method.

[0061] 4 and 5, a floating diffusion FD is formed in the surface 30B portion of the semiconductor substrate 30. This completes the transfer transistor TR. The floating diffusion FD is formed in the same process as the process of forming the pairs of main electrodes of the reset transistor RST, the amplification transistor AMP, and the selection transistor SEL after the gate insulating film 52 and the gate electrode 53 are formed.

[0062] When this series of manufacturing steps is completed, the photodetector 1 according to the first embodiment is completed.

[0063] [Effects] As shown in FIGS. 3 and 4, the photodetector 1 according to the first embodiment includes a photoelectric conversion element PD, a floating diffusion FD, and a transfer transistor TR. The photoelectric conversion element PD converts light L into an electric charge. The floating diffusion FD is disposed in the direction opposite to the arrow Z direction and spaced apart from the photoelectric conversion element PD. The transfer transistor TR includes a channel formation region 40 and a gate electrode 43. The channel formation region 40 is disposed between the photoelectric conversion element PD and the floating diffusion FD, and is disposed so as to overlap the floating diffusion FD in a planar view. The gate electrode 43 is disposed between the photoelectric conversion element PD and the floating diffusion FD, and is disposed in the channel formation region 40 with a gate insulating film 42 interposed therebetween. Furthermore, the gate electrode 43 is disposed so as to overlap the photoelectric conversion element PD in a planar view. Here, one of a pair of main electrodes of the transfer transistor TR is a photoelectric conversion element PD, and the other of the pair of main electrodes is a floating diffusion FD. Also, a channel formation region 40 of the transfer transistor TR is formed in a columnar shape with a height from the photoelectric conversion element PD to the floating diffusion FD. In the photodetector 1 configured in this manner, the channel formation region 40 of the transfer transistor TR and further the gate electrode 43 can be arranged to overlap the floating diffusion FD in a plan view. This allows the area of ​​the pixel 10 to be reduced. Moreover, in the transfer transistor TR, a channel can be formed on the center side of the channel formation region 40 away from the vicinity of the interface of the channel formation region 40 (semiconductor substrate 30) along the gate electrode 43. Therefore, it is possible to effectively suppress or prevent trapping or detrapping of carriers caused by crystal defects occurring in the vicinity of the interface of the channel formation region 40, and therefore it is possible to effectively suppress or prevent the generation of noise. In addition, in the photodetector 1, the photoelectric conversion element PD, the channel formation region 40 of the transfer transistor TR, and the floating diffusion FD are arranged to overlap each other. Therefore, the charge converted from light L by the photoelectric conversion element PD is transferred to the floating diffusion FD in the direction of the arrow Z (vertical direction) through the transfer transistor TR. In other words, the energy potential structure for transferring the charge is simplified to only the vertical direction. As a manufacturing method, the number of times of implanting impurities to form the energy potential structure can be effectively reduced. Therefore, it is possible to provide a photodetector 1 that can reduce the area of ​​the pixel 10 (area of ​​the element), effectively suppress or prevent the occurrence of noise, and further simplify the structure of the carrier transfer path.

[0064] In the photodetector 1, the gate electrode 43 of the transfer transistor TR is disposed so as to surround the columnar side surface of the channel formation region 40, as shown in FIGS. Here, the floating diffusion FD is formed in a circular shape in plan view, and the gate electrode 43 of the transfer transistor TR is formed in a circular ring shape in plan view. In the photodetector 1 configured in this manner, the transfer transistor TR can form a channel in the central part of the channel formation region 40 away from the vicinity of the interface between the channel formation region 40 and the gate insulating film 42 due to the electric field effect from the gate electrode 43. This makes it possible to more effectively suppress or prevent the generation of noise.

[0065] In the photodetector 1, as shown in FIGS. 4 and 5, an insulator 6 is disposed along the periphery of the side surface of the floating diffusion FD on the side surface opposite to the direction of arrow Z of the gate electrode 43 of the transfer transistor TR. Here, the thickness of the insulator 6 in the direction of the arrow Z is greater than the thickness of the gate insulating film 42 from the channel formation region 40 to the gate electrode 43 . In the photodetector 1 configured in this manner, the parasitic capacitance added to the floating diffusion FD can be effectively reduced, thereby realizing an increase in the speed at which charges are read out from the photoelectric conversion element PD to the pixel circuit 20.

[0066] <2. Second embodiment> The photodetector 1 according to the second embodiment will be described with reference to FIGS. In the second and subsequent embodiments, components that are the same as or substantially the same as the components of the photodetector 1 according to the first embodiment are given the same reference numerals, and duplicated explanations will be omitted.

[0067] [Method of manufacturing the photodetector 1] 6 to 13 show an example of process cross sections for explaining each step of the method for manufacturing the photodetector 1. FIG. The method for manufacturing the photodetector 1 according to the second embodiment is an example in which the method for manufacturing the transfer transistor TR of the pixel 10 is changed from the method for manufacturing the photodetector 1 according to the first embodiment. The method for manufacturing the photodetector 1 is as follows.

[0068] First, similarly to the process shown in Fig. 6 of the manufacturing method of the photodetector 1 according to the first embodiment (hereinafter simply referred to as the "first manufacturing method"), a semiconductor substrate 30 is prepared as shown in Fig. 14. This semiconductor substrate 30 is in the state of a semiconductor wafer before a dicing process, in which pixel isolation regions 31 and photoelectric conversion elements PD are formed.

[0069] Next, similarly to the first manufacturing method, a mask 301 and a mask 302 are sequentially formed on the surface 30B of the semiconductor substrate 30. The masks 301 and 302 have openings in regions where the gate electrodes 43 of the transfer transistors TR are to be formed (see FIG. 15). 7 of the first manufacturing method, a groove 303 is formed from the surface 30B of the semiconductor substrate 30 to the photoelectric conversion element PD using a mask 301 and a mask 302 as shown in Fig. 15. When the groove 303 is formed, a cylindrical channel formation region 40 of the transfer transistor TR is formed.

[0070] 11 of the first manufacturing method, an insulator 60 is embedded in the groove 303 as shown in Fig. 16. The insulator 60 is formed by using, for example, a CVD method or a sputtering method, and is made of SiO2 here. In the manufacturing method of the photodetector 1 according to the second embodiment, the insulator 60 is first embedded in the groove 303.

[0071] 17, the insulator 60 is patterned to expose a part of the groove 303 around the side surface of the channel formation region 40. The patterning is performed by an etching method using a mask (not shown) formed by photolithography technology.

[0072] A gate insulating film 42 is formed along the side and bottom surfaces of the partially exposed trench 303, that is, along at least the side surfaces of the channel formation region 40 (see FIG. 18). 11 of the first manufacturing method, a gate electrode material 43A is then buried in the partially exposed trench 303 with a gate insulating film 42 therebetween, as shown in FIG.

[0073] 12 of the first manufacturing method, a part of the gate electrode material 43A is removed on the front surface 30B side of the semiconductor substrate 30, as shown in Fig. 19. The amount of the gate electrode material 43A removed corresponds to the depth of the floating diffusion FD in the direction of the arrow Z. In this step, the gate electrode 43 of the transfer transistor TR is substantially completed.

[0074] As in the step shown in FIG. 13 of the first manufacturing method, as shown in FIG. 20, an insulator 6 is formed in the region where part of the gate electrode material 43A has been removed.

[0075] 4 and 5 of the photodetector 1 according to the first embodiment described above, a floating diffusion FD is formed on the surface 30B of the semiconductor substrate 30. This completes the transfer transistor TR. When this series of manufacturing steps is completed, the photodetector 1 according to the first embodiment is completed.

[0076] The components of the second embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0077] [Effects] According to the photodetector 1 of the second embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the first embodiment.

[0078] <3. Third embodiment> A photodetector 1 according to a third embodiment will be described with reference to FIG.

[0079] [Configuration of photodetector 1] FIG. 21 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the third embodiment, the floating diffusion FD has a rectangular planar shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is rectangular like the planar shape of the floating diffusion FD, and the channel formation region 40 is formed into a rectangular pillar shape. The gate electrode 43 surrounds the side periphery of the channel formation region 40 and is formed into a rectangular ring shape in a plan view.

[0080] The components of the third embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0081] [Effects] According to the photodetector 1 of the third embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the first embodiment.

[0082] <4. Fourth embodiment> A photodetector 1 according to a fourth embodiment will be described with reference to FIG.

[0083] [Configuration of photodetector 1] FIG. 22 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the fourth embodiment, the planar shape of the floating diffusion FD is formed to be polygonal in plan view. Here, the planar shape of the floating diffusion FD is formed to be octagonal. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a polygonal shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a polygonal column shape. The gate electrode 43 surrounds the side periphery of the channel formation region 40 and is formed in a polygonal ring shape in a planar view.

[0084] The components of the fourth embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0085] [Effects] According to the photodetector 1 of the fourth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the first embodiment.

[0086] In addition, in the present technology, the planar shape of the floating diffusion FD may be formed to be a pentagon or a polygon having octagons or more sides. Also, in the present technology, the planar shape of the floating diffusion FD may be formed to be an ellipse. In response to such changes in shape, the present technology may change the planar shape of the channel formation region 40 of the transfer transistor TR to a corresponding shape.

[0087] <5. Fifth embodiment> The photodetector 1 according to the fifth embodiment will be described with reference to FIG.

[0088] [Configuration of photodetector 1] FIG. 23 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the fifth embodiment, similarly to the photodetector 1 according to the fourth embodiment, the planar shape of the floating diffusion FD is formed into a polygonal shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a polygonal shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a polygonal columnar shape. A plurality of gate electrodes 43 are disposed along the periphery of the side surface of the channel formation region 40. More specifically, the gate electrode 43 is formed in a rectangular shape with one side equal to the length of one side of the polygonal shape of the channel formation region 40 in a plan view. Three gate electrodes 43 are disposed at equal intervals along the periphery of the side surface of the channel formation region 40. The same control signal is input to each gate electrode 43.

[0089] The components of the fifth embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the fourth embodiment.

[0090] [Effects] According to the photodetector 1 of the fifth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the fourth embodiment.

[0091] <6. Sixth embodiment> A photodetector 1 according to a sixth embodiment will be described with reference to FIG.

[0092] [Configuration of photodetector 1] FIG. 24 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the sixth embodiment, similarly to the photodetector 1 according to the third embodiment, the floating diffusion FD has a rectangular planar shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a rectangular shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a rectangular pillar shape. A plurality of gate electrodes 43 are disposed along the periphery of the side surface of the channel formation region 40. More specifically, the gate electrodes 43 are disposed facing each other with the channel formation region 40 interposed therebetween in a plan view. Two gate electrodes 43 are disposed and spaced apart in the direction of the arrow X. The same control signal is input to each gate electrode 43.

[0093] The components of the sixth embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the third embodiment.

[0094] [Effects] According to the photodetector 1 of the sixth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the third embodiment.

[0095] <7. Seventh embodiment> A photodetector 1 according to a seventh embodiment will be described with reference to FIG.

[0096] [Configuration of photodetector 1] FIG. 25 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the seventh embodiment, similarly to the photodetector 1 according to the sixth embodiment, the floating diffusion FD has a rectangular planar shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a rectangular shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a rectangular pillar shape. The gate electrode 43 is disposed along a part of the periphery of the side surface of the channel formation region 40. More specifically, the gate electrode 43 is disposed from one side in the direction of the arrow X to one side in the direction of the arrow Y in a plan view. The gate electrode 43 has an L-shape in plan view.

[0097] The components of the seventh embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the sixth embodiment.

[0098] [Effects] According to the photodetector 1 of the seventh embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the sixth embodiment.

[0099] <8. Eighth embodiment> The photodetector 1 according to the eighth embodiment will be described with reference to FIG.

[0100] [Configuration of photodetector 1] FIG. 26 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the eighth embodiment, similarly to the photodetector 1 according to the third embodiment, the floating diffusion FD has a rectangular planar shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a rectangular shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a rectangular pillar shape. The gate electrode 43 is disposed along the periphery of the side surface of the channel formation region 40. That is, the gate electrode 43 is formed in a rectangular ring shape in a plan view.

[0101] In plan view, the channel formation region 40 is formed in a shape that protrudes (or is recessed) in the direction of the arrow Y and in the direction opposite to the direction of the arrow Y. On the other hand, the gate electrode 43 is formed in a shape that is recessed (or protrudes) in the direction opposite to the direction of the arrow Y and in the direction of the arrow Y. In other words, the shape of the channel formation region 40 is configured to fit into the shape of the gate electrode 43.

[0102] The components of the eighth embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the third embodiment.

[0103] [Effects] According to the photodetector 1 of the eighth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the third embodiment.

[0104] 26, in the photodetector 1, the channel formation region 40 of the transfer transistor TR is formed in a protruding shape in a plan view, and the gate electrode 43 is formed in a recessed shape that fits into the channel formation region 40. This increases the gate width of the transfer transistor TR, effectively increasing the channel area, and thus increasing the charge transfer speed.

[0105] <9. Ninth embodiment> The photodetector 1 according to the ninth embodiment will be described with reference to FIG.

[0106] [Configuration of photodetector 1] FIG. 27 shows an example of a planar configuration of a part (transfer transistor TR) of a pixel 10 of the photodetector 1. As shown in FIG. In the photodetector 1 according to the ninth embodiment, similarly to the photodetector 1 according to the eighth embodiment, the floating diffusion FD has a rectangular planar shape in plan view. The planar shape of the channel formation region 40 of the transfer transistor TR is formed in a rectangular shape similar to the planar shape of the floating diffusion FD, and the channel formation region 40 is formed in a rectangular pillar shape. The gate electrode 43 is disposed along the periphery of the side surface of the channel formation region 40. That is, the gate electrode 43 is formed in a rectangular ring shape in a plan view.

[0107] In plan view, the channel formation region 40 is formed in a shape that protrudes (or is recessed) in the direction of the arrow Y, the direction opposite to the direction of the arrow Y, the direction of the arrow X, and the direction opposite to the direction of the arrow X. On the other hand, the gate electrode 43 is formed in a shape that is recessed (or protrudes) in the direction opposite to the direction of the arrow Y, the direction of the arrow Y, the direction opposite to the direction of the arrow X, and the direction of the arrow X. The shape of the channel formation region 40 is configured to fit into the shape of the gate electrode 43.

[0108] The components of the ninth embodiment other than the above-mentioned components are the same or substantially the same as the components of the photodetector 1 according to the eighth embodiment.

[0109] [Effects] According to the photodetector 1 of the ninth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the eighth embodiment.

[0110] <10. Tenth embodiment> The photodetector 1 according to the tenth embodiment will be described with reference to FIGS.

[0111] [Configuration of photodetector 1] Fig. 28 shows an example of a cross-sectional configuration of the pixel 10 and the pixel circuit 20 of the photodetector 1. Fig. 29 shows an example of a planar configuration of a part of the pixel 10 and a part of the pixel circuit 20. In the photodetection device 1 according to the tenth embodiment, phase difference detection pixels 10PD are arranged in at least a part of the pixel region 100. Here, the phase difference detection pixels 10PD are configured of a first pixel 10A and a second pixel 10B arranged adjacent to each other in the direction of the arrow X.

[0112] The first pixel 10A of the phase difference detection pixel 10PD is formed in a rectangular shape with the direction of the arrow X as the short side direction and the direction of the arrow Y as the long side direction in a plan view. A pixel isolation region 31 is disposed around the first pixel 10A. Similarly, the second pixel 10B is formed in a rectangular shape with the direction of the arrow X as the short side direction and the direction of the arrow Y as the long side direction. A pixel isolation region 31 is disposed around the second pixel 10B.

[0113] The first pixel 10A includes a photoelectric conversion element PD and a transfer transistor TR. The photoelectric conversion element PD and the transfer transistor TR have the same structures as the photoelectric conversion element PD and the transfer transistor TR of the photodetector 1 according to the first embodiment. In addition, one transistor Tr constituting the pixel circuit 20 is disposed in the region corresponding to the first pixel 10A. The transistor Tr is a reset transistor RST, an amplification transistor AMP, or a selection transistor SEL. The transistor Tr is disposed in a p-type semiconductor region 31p serving as a p-type well region.

[0114] The second pixel 10B includes a photoelectric conversion element PD and a transfer transistor TR. In addition, one transistor Tr constituting a pixel circuit 20 is disposed in a region corresponding to the second pixel 10B.

[0115] The p-type semiconductor region 31p of the first pixel 10A and the p-type semiconductor region 31p of the second pixel 10B are integrally formed (shared) between the first pixel 10A and the second pixel 10B, and are electrically connected to wiring (not shown). A well voltage is supplied to the p-type semiconductor region 31p from the wiring.

[0116] In the tenth embodiment, the phase difference detection pixel 10PD is adjacent to another phase difference detection pixel 10PD in the direction of the arrow Y. Each phase difference detection pixel 10PD is formed in a line symmetric shape with respect to a center line CL extending in the direction of the arrow X shown for convenience. The gate electrodes 43 of the phase difference detection pixels 10PD are integrally formed (shared) in a region corresponding to the pixel isolation region 31, and are electrically connected to wiring (not shown). A control signal is supplied to the gate electrode 43 from the wiring. In addition, the portion where the gate electrode 43 is integrally formed in the region corresponding to the pixel isolation region 31 corresponds to a “lead wiring” that is drawn out from the gate electrode 43 .

[0117] The components of the tenth embodiment other than those described above are the same or substantially the same as the components of the photodetector 1 according to the first embodiment.

[0118] [Effects] According to the photodetector 1 of the tenth embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the first embodiment.

[0119] 28 and 29, the photodetection device 1 includes a phase difference detection pixel 10PD. Therefore, it is possible to obtain phase difference information from the photodetection information (image information) of each of the first pixel 10A and the second pixel 10B of the phase difference detection pixel 10PD, thereby realizing autofocus.

[0120] <11. Eleventh embodiment> The photodetector 1 according to the eleventh embodiment will be described with reference to FIGS.

[0121] [Configuration of photodetector 1] Fig. 30 shows an example of a cross-sectional configuration of the pixel 10 and the pixel circuit 20 of the photodetector 1. Fig. 31 shows an example of a planar configuration of a part of the pixel 10 and the pixel circuit 20. The photodetector 1 according to the eleventh embodiment includes a phase difference detection pixel 10PD, similar to the photodetector 1 according to the tenth embodiment. In the phase difference detection pixel 10PD, a transfer transistor TR, a floating diffusion FD, and a reset transistor RST of a pixel circuit 20 are sequentially arranged and electrically connected from the photoelectric conversion element PD in the opposite direction to the arrow Z direction. Further, apart from these arrangements and in parallel, an amplification transistor AMP and a selection transistor SEL of the pixel circuit 20 are sequentially arranged and electrically connected in the opposite direction to the arrow Z direction.

[0122] A detailed description will be given. The transfer transistor TR has a channel formation region 40A. One end of the channel formation region 40A is electrically connected to the photoelectric conversion element PD. The other end of the channel formation region 40A extends in a direction away from the photoelectric conversion element PD. A gate electrode 43 is disposed around the side surface of the channel formation region 40A with a gate insulating film 42 interposed therebetween. The transfer transistor TR corresponds to a "first transistor" according to the present technology. The channel formation region 40A corresponds to a "first channel formation region" according to the present technology. In the transfer transistor TR, the gate electrode 53 corresponds to a "first gate electrode" according to the present technology, and the main electrode (n-type semiconductor region 50) corresponds to a "first source region" or a "first drain region" according to the present technology.

[0123] The floating diffusion FD has one end electrically connected to the other end of the channel formation region 40A, and the other end extending in the direction opposite to the direction of the arrow Z. The floating diffusion FD is formed by an n-type semiconductor region 50.

[0124] The reset transistor RST has a channel formation region 40B. One end of the channel formation region 40B is electrically connected to the other end of the floating diffusion FD. The other end of the channel formation region 40B extends in the opposite direction to the direction of the arrow Z. A gate electrode 53 is disposed around the side surface of the channel formation region 40B with a gate insulating film 52 interposed therebetween. The other end of the channel formation region 40B is electrically connected to a power supply voltage VDD. The power supply voltage VDD is formed by an n-type semiconductor region 50. The reset transistor RST corresponds to a "second transistor" according to the present technology. The channel formation region 40B corresponds to a "second channel formation region" according to the present technology. In the reset transistor RST, the gate electrode 53 corresponds to a "second gate electrode" according to the present technology, and the main electrode (n-type semiconductor region 50) corresponds to a "second source region" or a "second drain region" according to the present technology. The channel formation region 40B and the gate electrode 53 of the reset transistor RST are disposed so as to overlap the channel formation region 40A and the gate electrode 53 of the transfer transistor TR in a plan view.

[0125] The amplification transistor AMP is disposed apart from the channel formation region 40A of the transfer transistor TR in the direction of the arrow Y, and has a channel formation region 40C extending in the opposite direction to the direction of the arrow Z. One end of the channel formation region 40C is electrically connected to a power supply voltage VDD. The power supply voltage VDD is formed by an n-type semiconductor region 50. A gate electrode 53 is disposed around the side surface of the channel formation region 40C with a gate insulating film 52 interposed therebetween. The amplification transistor AMP corresponds to a "third transistor" according to the present technology. The channel formation region 40C corresponds to a "third channel formation region" according to the present technology. In the amplification transistor AMP, the gate electrode 53 corresponds to a "third gate electrode" according to the present technology.

[0126] The selection transistor SEL is disposed apart from the channel formation region 40B in the direction of the arrow Y, and has a channel formation region 40D extending in the opposite direction to the direction of the arrow Z. One end of the channel formation region 40D is electrically connected to the other end of the channel formation region 40C. The other end of the channel formation region 40D is electrically connected to the vertical signal line Lv. The vertical signal line Lv is formed of an n-type semiconductor region 50. A gate electrode 53 is disposed around the side surface of the channel formation region 40D with a gate insulating film 52 interposed therebetween. The amplifying transistor AMP corresponds to a "fourth transistor" according to the present technology. Moreover, the channel formation region 40D corresponds to a "fourth channel formation region" according to the present technology. The amplification transistor AMP and the selection transistor SEL are arranged to overlap each other in plan view, similar to the reset transistor RST and the transfer transistor TR.

[0127] The components of the eleventh embodiment other than those described above are the same or substantially the same as the components of the photodetector 1 according to the tenth embodiment. The photodetector 1 corresponds to a "semiconductor device" according to the present technology.

[0128] [Effects] According to the photodetector 1 of the eleventh embodiment, it is possible to obtain the same advantageous effects as those obtained by the photodetector 1 of the tenth embodiment.

[0129] In the photodetector 1, in the phase difference detection pixel 10PD, the transfer transistor TR, the reset transistor RST, the amplification transistor AMP, and the selection transistor SEL are arranged in the direction opposite to the direction of the arrow Z from the photoelectric conversion element PD. This makes it possible to reduce the area of ​​the phase difference detection pixel 10PD.

[0130] <12. Twelfth embodiment> The photodetector 1 according to the twelfth embodiment of the present disclosure will be described with reference to FIG. FIG. 32 shows an example of a block configuration of the electronic device 700. As shown in FIG.

[0131] [Configuration of electronic device 700] 32, electronic device 700 includes photodetector 1 according to any one of the first to eleventh embodiments as photodetector 70. Photodetector 70 is applied to various electronic devices such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, and other devices with imaging functions.

[0132] The electronic device 700 includes an optical system 71, a photodetector 70, and a DSP (Digital Signal Processor) 72. In the electronic device 700, the DSP 72, a display device 73, an operation system 74, a memory 75, a recording device 76, and a power supply system 77 are connected via a bus 78. The electronic device 700 is capable of capturing still images and moving images.

[0133] The optical system 71 includes one or more lenses. The optical system 71 guides image light (incident light) from a subject to the light detection device 70, and forms an image on the light receiving surface (sensor unit) of the light detection device 70.

[0134] The photodetector 70 uses, for example, the photodetector 1 according to any one of the first to eleventh embodiments. In the photodetector 70, electrons are accumulated for a certain period of time according to an image formed on a light receiving surface through an optical system 71. Then, a signal according to the electrons accumulated in the photodetector 70 is supplied to a DSP 72.

[0135] The DSP 72 performs various signal processing on the signal from the photodetector 70 to obtain an image, and temporarily stores the image data in the memory 75. The image data stored in the memory 75 is recorded in the recording device 76. The image data stored in the memory 75 is also supplied to the display device 73, and the image is displayed on the display device 73. The operation system 74 accepts various operations by the user and supplies operation signals to each block of the electronic device 700. The power supply system 77 supplies power necessary to drive each block of the electronic device 700.

[0136] [Effects] 32, an electronic device 700 according to the twelfth embodiment includes a photodetector 70. As described in the photodetector 1 according to any one of the first to eleventh embodiments, the photodetector 70 is formed to include the phase difference detection pixels 10PD over the entire surface of the pixel region 100, for example. This can improve the phase difference detection accuracy of the electronic device 700.

[0137] <13. Application examples for mobile devices> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.

[0138] FIG. 33 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0139] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 33, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053 are shown.

[0140] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0141] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0142] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0143] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0144] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0145] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0146] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0147] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0148] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 33, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0149] FIG. 34 is a diagram showing an example of the installation position of the imaging unit 12031.

[0150] In FIG. 34, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0151] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the upper part of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0152] 34 shows an example of the imaging ranges of the imaging units 12101 to 12104. An imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and an imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0153] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0154] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0155] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0156] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0157] An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 among the configurations described above. By applying the technology according to the present disclosure to the imaging unit 12031, it is possible to realize an imaging unit 12031 that can reduce the pixel area, effectively suppress or prevent noise generation, and further simplify the structure of the carrier transfer path.

[0158] <14. Application to endoscopic surgery system> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0159] FIG. 35 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) can be applied.

[0160] 35 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0161] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0162] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0163] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0164] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0165] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0166] The light source device 11203 is composed of a light source such as an LED (light emitting diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0167] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0168] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0169] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0170] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0171] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0172] FIG. 36 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0173] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so as to be able to communicate with each other.

[0174] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0175] The imaging unit 11402 may include one imaging element (so-called single-plate type) or multiple imaging elements (so-called multiple-plate type). When the imaging unit 11402 is configured as a multiple-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to a 3D (dimensional) display. By performing a 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is configured as a multiple-plate type, the lens unit 11401 may also be provided in multiple systems corresponding to each imaging element.

[0176] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0177] The driving unit 11403 is configured by an actuator, and moves the zoom lens and 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. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0178] The communication unit 11404 is configured by 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 via the transmission cable 11400 as RAW data.

[0179] Furthermore, 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 information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0180] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0181] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0182] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0183] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0184] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0185] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0186] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0187] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0188] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0189] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 11402 of the camera head 11102 among the configurations described above. By applying the technology according to the present disclosure to the imaging unit 11402, it is possible to realize an imaging unit 11402 that can reduce the pixel area, effectively suppress or prevent noise generation, and further simplify the structure of the carrier transfer path.

[0190] Although an endoscopic surgery system has been described here as an example, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0191] <15. Other embodiments> The present technology is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present technology. For example, among the photodetection devices according to the first to eleventh embodiments, two or more of the photodetection devices according to the embodiments may be combined.

[0192] The photodetector according to the first embodiment of the present disclosure includes a photoelectric conversion element, a floating diffusion, and a transistor. The photoelectric conversion element converts light into an electric charge. The floating diffusion is disposed spaced apart from the photoelectric conversion element in a first direction. The transistor includes a channel formation region and a gate electrode. The channel formation region is disposed between the photoelectric conversion element and the floating diffusion, and is disposed so as to overlap the floating diffusion when viewed from the first direction. The gate electrode is disposed between the photoelectric conversion element and the floating diffusion, and is disposed in the channel formation region with a gate insulating film interposed therebetween. According to a photodetector configured in this manner, it is possible to reduce the area of ​​the pixels, effectively suppress or prevent the occurrence of noise, and further simplify the structure of the carrier transfer path.

[0193] A photodetector according to a second embodiment of the present disclosure is the photodetector according to the first embodiment, in which an insulator is disposed on a side of the gate electrode in a first direction along the periphery of the side of the floating diffusion. According to the photodetector configured in this manner, the parasitic capacitance added to the floating diffusion can be effectively reduced, thereby realizing an increase in the speed at which charges are read out from the photoelectric conversion element to the pixel circuit.

[0194] A photodetector according to a third embodiment of the present disclosure includes a photoelectric conversion element, a first transistor, a floating diffusion, and a second transistor. The photoelectric conversion element converts light into an electric charge. The first transistor has one end electrically connected to the photoelectric conversion element and a first channel formation region extending in a first direction away from the photoelectric conversion element. The floating diffusion has one end electrically connected to the other end of the first channel formation region and extends in the first direction. The second transistor has one end electrically connected to the other end of the floating diffusion and a second channel formation region extending in the first direction. According to the photodetector configured in this manner, the photoelectric conversion element, the first transistor, the floating diffusion, and the second transistor can be arranged in the first direction, so that the area of ​​the pixel can be reduced.

[0195] A photodetector according to a fourth embodiment of the present disclosure includes the photodetector according to the third embodiment, further comprising a third transistor and a fourth transistor. The third transistor is disposed apart from the first channel formation region in a second direction intersecting the first direction and has a third channel formation region extending in the first direction. The fourth transistor is disposed apart from the second channel formation region in the second direction, is electrically connected to the third channel formation region, and has a fourth channel formation region extending in the first direction. According to the photodetector configured in this manner, the photoelectric conversion element, the third transistor, and the fourth transistor can be arranged in the first direction, so that the area of ​​the pixel can be reduced.

[0196] <Configuration of this technology> The present technology has the following configuration. According to the present technology having the following configuration, in a photodetector, it is possible to reduce the area of ​​a pixel, effectively suppress or prevent the occurrence of noise, and further simplify the structure of a carrier transfer path. (1) A photoelectric conversion element that converts light into an electric charge; a floating diffusion disposed apart from the photoelectric conversion element in a first direction; a transistor electrically connecting the photoelectric conversion element and the floating diffusion; The transistor is a channel formation region disposed between the photoelectric conversion element and the floating diffusion and overlapping the floating diffusion when viewed from a first direction; a gate electrode disposed between the photoelectric conversion element and the floating diffusion and disposed in the channel forming region with a gate insulating film interposed therebetween; A light detection device comprising: (2) one of a pair of main electrodes of the transistor is the photoelectric conversion element, The other of the pair of main electrodes is the floating diffusion. The light detection device according to (1) above. (3) The channel formation region is formed in a columnar shape having a height from the photoelectric conversion element to the floating diffusion. The optical detection device according to (1) or (2). (4) The gate electrode is disposed so as to overlap the photoelectric conversion element when viewed from a first direction, and a plurality of gate electrodes are disposed along a periphery of a columnar side surface of the channel formation region. The optical detection device according to (3) above. (5) The gate electrodes are arranged to overlap the photoelectric conversion element when viewed from a first direction, and are arranged to face each other with the channel formation region interposed therebetween. The light detection device according to (4) above. (6) The gate electrode is disposed so as to overlap the photoelectric conversion element when viewed from a first direction, and is disposed so as to surround a columnar side surface of the channel formation region. The optical detection device according to (3) above. (7) When viewed from a first direction, the floating diffusion is formed in a circular, rectangular or polygonal shape. The photodetector according to any one of (1) to (6). (8) When viewed from a first direction, the gate electrode is formed in a circular ring shape, a rectangular ring shape, or a polygonal ring shape. The photodetector according to any one of (1) to (7). (9) When viewed from a first direction, the channel formation region is formed in a shape that protrudes toward a second direction that intersects with the first direction, When viewed from a first direction, the gate electrode is formed in a shape recessed toward a second direction and fitted into the shape of the channel formation region. The photodetector according to any one of (3) to (7). (10) An insulator is disposed along a side periphery of the floating diffusion and on a side surface of the gate electrode in a first direction. The photodetector according to any one of (1) to (10). (11) The thickness of the insulator in the first direction is greater than the thickness of the gate insulating film from the channel formation region to the gate electrode. The optical detection device according to (10) above. (12) a pixel isolation region that optically and electrically isolates the photoelectric conversion element from other regions around a side surface of the photoelectric conversion element; The photoelectric conversion element constitutes a pixel. The photodetector according to any one of (1) to (11). (13) The pixels are arranged in a second direction intersecting the first direction to form a pixel region. The light detection device according to (12) above. (14) A plurality of the pixels arranged in at least a part of the pixel region and adjacent to each other in the second direction are surrounded by one of the pixel separation regions, forming a phase difference detection pixel. The optical detection device according to (13) above. (15) In the pixel region, the gate electrodes of the pixels adjacent to each other in a second direction are electrically connected to each other, The gate electrodes electrically connected to each other are electrically connected to wiring that supplies the same signal. The photodetector according to any one of (12) to (14). (16) When viewed from a first direction, a planar area of ​​the gate electrode is smaller than a planar area of ​​the photoelectric conversion element, and the entire gate electrode overlaps the photoelectric conversion element. The photodetector according to any one of (1) to (15). (17) A photoelectric conversion element that converts light into an electric charge; a first transistor having a first channel formation region, one end of the first channel formation region being electrically connected to the photoelectric conversion element and the other end of the first channel formation region being extended in a first direction away from the photoelectric conversion element; a floating diffusion having one end electrically connected to the other end of the first channel formation region and the other end extending in a first direction; a second transistor having a second channel forming region, one end of the second channel forming region being electrically connected to the other end of the floating diffusion, and the other end of the second channel forming region being extended in a first direction; A light detection device comprising: (18) a third transistor that is disposed apart from the first channel formation region in a second direction intersecting the first direction and has a third channel formation region that extends in the first direction; a fourth transistor disposed apart from the second channel formation region in the second direction, electrically connected to the third channel formation region, and having a fourth channel formation region extending in the first direction. The light detection device according to (17) above. (19) the photoelectric conversion element is electrically connected to a pixel circuit that reads out charges converted in the photoelectric conversion element through a transfer transistor; the first transistor is the transfer transistor, The second transistor is a reset transistor that constitutes the pixel circuit. The optical detection device according to (18) above. (20) the third transistor is an amplification transistor that constitutes the pixel circuit, The fourth transistor is a selection transistor that constitutes the pixel circuit. The light detection device according to (19) above. (twenty one) The floating diffusion is electrically connected to the gate electrode of the amplification transistor. The light detection device according to (20) above. (twenty two) a source region and a drain region spaced apart in a first direction; a channel formation region disposed between the source region and the drain region and overlapping one of the source region and the drain region when viewed from a first direction; a gate electrode disposed between the source region and the drain region and disposed on the channel forming region with a gate insulating film interposed therebetween; A semiconductor device comprising: (twenty three) a first transistor having a first channel formation region, one end of the first channel formation region being electrically connected to one of a source region and a drain region, and the other end of the first channel formation region being extended in a first direction away from one of the source region and the drain region; a second transistor having a second channel formation region, one end of the second channel formation region being electrically connected to the other end of the first channel formation region, and the other end of the second channel formation region being extended in a first direction; A semiconductor device comprising: (twenty four) a first transistor including a first source region, a first drain region, a first channel forming region and a first gate electrode; a second transistor including a second channel formation region and a second gate electrode, the second transistor being electrically connected to the first transistor; A semiconductor device, wherein, in a plan view, the first gate electrode, the first channel formation region, the second gate electrode, and the second channel formation region overlap one of the first source region and the first drain region. (twenty five) the second transistor includes a second source region and a second drain region; The second transistor includes the other of the first source region and the first drain region as one of the second source region and the second drain region. The semiconductor device according to (24) above. (26) a third transistor including a third gate electrode; The third gate electrode is electrically connected to the other of the first source region and the first drain region. The semiconductor device according to (24) or (25). [Explanation of symbols]

[0197] 1, 70...photodetector, 10...pixel, 1A...first substrate, 1B...second substrate, 1C...third substrate, 10A...first pixel, 10B...second pixel, 10PD...phase difference detection pixel, 100...pixel region, 20...pixel circuit, 30...semiconductor substrate, 30p, 31p...p-type semiconductor region, 30n, 50...n-type semiconductor region, 31...pixel separation region, 40, 40A to 40D...channel formation region, 42, 52...gate insulating film, 43, 53...gate electrode, 6, 60...insulator, 7...protective film, 700...electronic device, 8...optical filter, 9...optical lens, PD...photoelectric conversion element, Tr...transistor, TR...transfer transistor, RST...reset transistor, AMP...amplifying transistor, SEL...selection transistor, FD...floating diffusion.

Claims

1. A photoelectric conversion element that converts light into an electric charge; a floating diffusion disposed apart from the photoelectric conversion element in a first direction; a transistor electrically connecting the photoelectric conversion element and the floating diffusion; The transistor is a channel formation region disposed between the photoelectric conversion element and the floating diffusion and overlapping the floating diffusion when viewed from a first direction; a gate electrode disposed between the photoelectric conversion element and the floating diffusion and disposed in the channel forming region with a gate insulating film interposed therebetween; A photodetector comprising:

2. one of a pair of main electrodes of the transistor is the photoelectric conversion element, The other of the pair of main electrodes is the floating diffusion.

2. The optical detection device according to claim 1.

3. The channel formation region is formed in a columnar shape having a height from the photoelectric conversion element to the floating diffusion.

2. The optical detection device according to claim 1.

4. The gate electrode is disposed so as to overlap the photoelectric conversion element when viewed from a first direction, and a plurality of gate electrodes are disposed along a periphery of a columnar side surface of the channel formation region.

4. The optical detection device according to claim 3.

5. The gate electrodes are arranged to overlap the photoelectric conversion element when viewed from a first direction, and are arranged to face each other with the channel formation region interposed therebetween.

5. The optical detection device according to claim 4.

6. The gate electrode is disposed so as to overlap the photoelectric conversion element when viewed from a first direction, and is disposed so as to surround a columnar side surface of the channel formation region.

4. The optical detection device according to claim 3.

7. When viewed from a first direction, the floating diffusion is formed in a circular, rectangular or polygonal shape.

2. The optical detection device according to claim 1.

8. When viewed from a first direction, the gate electrode is formed in a circular ring shape, a rectangular ring shape, or a polygonal ring shape.

2. The optical detection device according to claim 1.

9. When viewed from a first direction, the channel formation region is formed in a shape that protrudes toward a second direction intersecting the first direction, When viewed from a first direction, the gate electrode is formed in a shape recessed toward a second direction and fitted into the shape of the channel formation region.

4. The optical detection device according to claim 3.

10. An insulator is disposed along a side periphery of the floating diffusion and on a side surface of the gate electrode in a first direction.

2. The optical detection device according to claim 1.

11. The thickness of the insulator in the first direction is greater than the thickness of the gate insulating film from the channel formation region to the gate electrode. The optical detection device according to claim 10.

12. a pixel isolation region that optically and electrically isolates the photoelectric conversion element from other regions around a side surface of the photoelectric conversion element; The photoelectric conversion element constitutes a pixel.

2. The optical detection device according to claim 1.

13. The pixels are arranged in a plurality of rows in a second direction intersecting the first direction to form a pixel region.

13. The optical detection device of claim 12.

14. A plurality of the pixels arranged in at least a part of the pixel region and adjacent to each other in the second direction are surrounded by one of the pixel isolation regions to constitute a phase difference detection pixel.

14. The optical detection device of claim 13.

15. In the pixel region, the gate electrodes of the pixels adjacent to each other in a second direction are electrically connected to each other, The gate electrodes electrically connected to each other are electrically connected to wiring that supplies the same signal.

13. The optical detection device of claim 12.

16. When viewed from a first direction, a planar area of ​​the gate electrode is smaller than a planar area of ​​the photoelectric conversion element, and the entire gate electrode overlaps the photoelectric conversion element.

2. The optical detection device according to claim 1.

17. A photoelectric conversion element that converts light into an electric charge; a first transistor having a first channel formation region, one end of the first channel formation region being electrically connected to the photoelectric conversion element and the other end of the first channel formation region being extended in a first direction away from the photoelectric conversion element; a floating diffusion having one end electrically connected to the other end of the first channel formation region and the other end extending in a first direction; a second transistor having a second channel forming region, one end of the second channel forming region being electrically connected to the other end of the floating diffusion, and the other end of the second channel forming region being extended in a first direction; A photodetector comprising:

18. a third transistor that is disposed apart from the first channel formation region in a second direction intersecting the first direction and has a third channel formation region that extends in the first direction; a fourth transistor disposed apart from the second channel formation region in the second direction, electrically connected to the third channel formation region, and having a fourth channel formation region extending in the first direction.

18. The optical detection device of claim 17.

19. the photoelectric conversion element is electrically connected to a pixel circuit that reads out charges converted in the photoelectric conversion element through a transfer transistor; the first transistor is the transfer transistor, The second transistor is a reset transistor that constitutes the pixel circuit.

20. The optical detection device of claim 18.

20. the third transistor is an amplification transistor that constitutes the pixel circuit, The fourth transistor is a selection transistor that constitutes the pixel circuit.

20. The optical detection device of claim 19.

21. The floating diffusion is electrically connected to the gate electrode of the amplification transistor.

21. The optical detection device of claim 20.

22. a source region and a drain region spaced apart in a first direction; a channel formation region disposed between the source region and the drain region and overlapping one of the source region and the drain region when viewed in a first direction; a gate electrode disposed between the source region and the drain region and disposed on the channel forming region with a gate insulating film interposed therebetween; A semiconductor device comprising:

23. a first transistor having a first channel forming region, one end of the first channel forming region being electrically connected to one of a source region and a drain region, and the other end of the first channel forming region being extended in a first direction away from one of the source region and the drain region; a second transistor having a second channel forming region, one end of the second channel forming region being electrically connected to the other end of the first channel forming region, and the other end of the second channel forming region being extended in a first direction; A semiconductor device comprising:

24. a first transistor including a first source region, a first drain region, a first channel forming region and a first gate electrode; a second transistor including a second channel forming region and a second gate electrode, the second transistor being electrically connected to the first transistor; A semiconductor device, wherein, in a plan view, the first gate electrode, the first channel formation region, the second gate electrode, and the second channel formation region overlap one of the first source region and the first drain region.

25. the second transistor includes a second source region and a second drain region; The second transistor includes the other of the first source region and the first drain region as one of the second source region and the second drain region. The semiconductor device according to claim 24.

26. a third transistor including a third gate electrode; The third gate electrode is electrically connected to the other of the first source region and the first drain region. The semiconductor device according to claim 24.

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