Solid-state imaging device and electronic equipment

Abstract

The solid-state imaging device according to the embodiment is provided with: a photoelectric conversion region, which is provided in an element region defined by a groove in a semiconductor substrate; a first semiconductor region, which surrounds the photoelectric conversion region; a first contact, which contacts the first semiconductor region at the bottom of the groove; a first electrode, which contacts the first contact in the first groove; a second semiconductor region, which is provided in a region contacting the first semiconductor region and has a first conductivity type that is the same as the conductivity type of the first semiconductor region; a third semiconductor region, which is adjacent to the second semiconductor region, is provided between the second semiconductor region and the first surface, and has a second conductivity type opposite to the first conductivity type; a second contact, which is provided on the first surface to contact the third semiconductor region; and a second electrode, which contacts the second contact. The second surface where the first contact and the first electrode are in contact is inclined relative to the first surface.

Description

Technical Field

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

[0002] In recent years, single photon avalanche diodes (SPADs) have been developed that amplify the charges generated by photoelectric conversion by avalanche multiplication (also called avalanche multiplication) and output them as electrical signals. Avalanche amplification is a phenomenon in which electrons accelerated by the electric field collide with lattice atoms in the impurity diffusion region of the PN junction to break bonds, and newly generated electrons collide with another lattice atom to break bonds, and the current is doubled by repeating this process.

[0003] Such a SPAD can be applied to: a distance measuring device that measures the distance to an object based on the time it takes for light emitted from a light emitting unit to reflect on the object and return; and a solid-state image sensor that converts the amount of incident light into an electrical signal, etc.

[0004] In order to discharge the large current generated by avalanche multiplication from the SPAD pixel, it is desirable to form a contact with low resistance and ohmic contact. As a method of forming a contact with low resistance and ohmic contact in an impurity diffusion region formed in a semiconductor substrate, it is known that a high concentration impurity region is generally formed in the contact portion.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: JP 2015-41746A Summary of the invention

[0008] Technical issues

[0009] Here, in order to obtain an electric field strength sufficient to generate avalanche amplification, a high voltage in the reverse bias direction needs to be applied to the PN junction. However, when the distance from the PN junction to the contact is short, a strong electric field is formed therebetween, and a tunnel effect is generated. When this tunnel effect occurs, the electron-hole pairs generated by photoelectric conversion are immediately recombined by the tunnel current, resulting in the problem that avalanche amplification cannot be generated.

[0010] In order to avoid the occurrence of tunneling effect, a method of arranging the contact at the outermost periphery of the impurity diffusion region to increase the distance from the PN junction region to the contact can be considered. However, in this case, it is difficult to ensure a large contact area between the contact and the electrode. Therefore, the sensitivity (photon detection efficiency (PDE)) is reduced due to the voltage drop caused by the high contact resistance. In the case of increasing the voltage value to suppress the reduction of PDE, power consumption increases.

[0011] Therefore, the present disclosure proposes a solid-state imaging device and an electronic device capable of suppressing high contact resistance and improving PDE.

[0012] Technical solutions to the problem

[0013] In order to solve the above-mentioned problems, a solid-state imaging device according to the present disclosure includes: a semiconductor substrate including a first groove provided on a first surface and a second groove provided along the bottom of the first groove; and a photoelectric conversion element provided on the semiconductor substrate, wherein the photoelectric conversion element includes: a photoelectric conversion region provided in an element region divided by the first groove and the second groove in the semiconductor substrate, and photoelectrically converting incident light to generate electric charge; a first semiconductor region surrounding the photoelectric conversion region in the element region; a first contact in contact with the first semiconductor region at the bottom of the first groove; a first electrode in contact with the first contact in the first groove; a second semiconductor region provided in a region in contact with the first semiconductor region in the element region, and having a first conductivity type which is the same as that of the first semiconductor region; a third semiconductor region serving as a region in contact with the second semiconductor region in the element region, provided between the second semiconductor region and the first surface, and having a second conductivity type which is opposite to the first conductivity type; a second contact provided on the first surface to contact with the third semiconductor region; and a second electrode in contact with the second contact, and a second surface where the first contact and the first electrode contact each other is inclined relative to the first surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a block diagram showing a schematic configuration example of an electronic device equipped with the solid-state image pickup device according to the first embodiment.

[0015] Figure 2 is a block diagram showing a schematic configuration example of an image sensor according to the first embodiment.

[0016] Figure 3 is a circuit diagram showing a schematic configuration example of a SPAD pixel according to the first embodiment.

[0017] Figure 4 is a diagram showing an example of a color filter layout according to the first embodiment.

[0018] Figure 5 is a diagram showing an example of a stacked structure of the image sensor according to the first embodiment.

[0019] Figure 6 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the first embodiment.

[0020] Figure 7 It shows Figure 6 A horizontal cross-sectional view of an example of a cross-sectional structure of plane AA.

[0021] Figure 8 1 is a process cross-sectional view showing the method for manufacturing the solid-state image pickup device according to the first embodiment (process 1).

[0022] Fig. 9 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 2).

[0023] Fig.10 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 3).

[0024] Fig.11 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 4 ).

[0025] Fig.12 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 5 ).

[0026] Fig.13 1 is a process cross-sectional view showing the method for manufacturing the solid-state image pickup device according to the first embodiment (process 6 ).

[0027] Fig.14 1 is a process cross-sectional view showing the method for manufacturing the solid-state image pickup device according to the first embodiment (process 7 ).

[0028] Fig.15 1 is a process cross-sectional view showing the method for manufacturing the solid-state image pickup device according to the first embodiment (process 8 ).

[0029] Fig.16 1 is a process cross-sectional view showing the method for manufacturing the solid-state image pickup device according to the first embodiment (process 9 ).

[0030] Fig.17 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 10 ).

[0031] Fig.18 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 11 ).

[0032] Fig.19 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 12 ).

[0033] Fig. 20 1 is a cross-sectional view showing a process of the method for manufacturing the solid-state image pickup device according to the first embodiment (process 13 ).

[0034] Fig.21 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of a SPAD pixel according to a first modification example of the first embodiment.

[0035] Fig. 22 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a second modification example of the first embodiment.

[0036] Fig.23 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of a SPAD pixel according to a third modification example of the first embodiment.

[0037] Fig.24 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of a SPAD pixel according to a fourth modification example of the first embodiment.

[0038] Fig.25 : is a diagram showing an example of connection wiring to an anode according to the first embodiment.

[0039] Fig.26 is a diagram showing an example of connection wiring to an anode according to a fifth modification of the first embodiment.

[0040] Fig. 27 is a diagram showing another example of the connection wiring to the anode according to the fifth modification of the first embodiment.

[0041] Fig.28 is a diagram showing still another example of connection wiring to an anode according to a fifth modification of the first embodiment.

[0042] Fig.29 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to the second embodiment.

[0043] Fig.30 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to the third embodiment.

[0044] Fig.31 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the fourth embodiment.

[0045] Fig.32: is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the fifth embodiment.

[0046] Fig.33 is a plan view showing an example of a plan layout of a SPAF pixel according to the sixth embodiment.

[0047] Fig.34 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the sixth embodiment.

[0048] Fig.35 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the seventh embodiment.

[0049] Fig.36 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the eighth embodiment.

[0050] Fig.37 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of the SPAD pixel according to the ninth embodiment.

[0051] Fig.38 It shows Fig.37 A horizontal cross-sectional view of an example of a cross-sectional structure of plane AA.

[0052] Fig.39 1 is a process cross-sectional view showing a method of manufacturing a solid-state image pickup device according to a ninth embodiment.

[0053] Fig.40 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a first modification example of the ninth embodiment.

[0054] Fig.41 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a second modification example of the ninth embodiment.

[0055] Fig.42 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a third modification example of the ninth embodiment.

[0056] Fig.43 1 is a diagram showing a configuration of an imaging device as an electronic device using a solid-state imaging element to which the present technology is applied.

[0057] Fig.44 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0058] Fig.45 1 is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection section and the camera unit.

[0059] Fig.46 is a diagram showing an example of a schematic configuration of an endoscopic surgery system.

[0060] Fig.47 is a block diagram showing an example of the functional configuration of a camera and a CCU. DETAILED DESCRIPTION

[0061] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in the following embodiments, the same components are denoted by the same reference numerals, and repeated descriptions are omitted.

[0062] Furthermore, the present disclosure will be described in the order of items shown below.

[0063] 1. First Embodiment

[0064] 1.1 Electronic equipment

[0065] 1.2 Solid-state camera device

[0066] 1.3SPAD pixels

[0067] 1.4 General Operation Example of SPAD Pixel

[0068] 1.5 Example of color filter layout

[0069] 1.6 Example of stacked structure of solid-state image sensor

[0070] 1.7 Example of a cross-sectional structure of a SPAD pixel

[0071] 1.8 Positional Relationship Between Anode Contact and Cathode Contact and / or N+ Type Semiconductor Region

[0072] 1.9 Manufacturing method

[0073] 1.10 Effect

[0074] 1.11 Modification

[0075] 1.11.1 First Modification

[0076] 1.11.2 Second Modification

[0077] 1.11.3 Third variant

[0078] 1.11.4 Fourth variant

[0079] 1.11.5 Fifth variant

[0080] 2. Second Embodiment

[0081] 3. Third embodiment

[0082] 4. Fourth embodiment

[0083] 5. Fifth embodiment

[0084] 6. Sixth embodiment

[0085] 7. Seventh embodiment

[0086] 8. Eighth Embodiment

[0087] 9. Ninth Embodiment

[0088] 9.1 Example of a cross-sectional structure of a SPAD pixel

[0089] 9.2 Effect

[0090] 9.3 Variations

[0091] 9.3.1 First Modification

[0092] 9.3.2 Second Modification

[0093] 9.3.3 Third variant

[0094] 10. Application examples of electronic equipment

[0095] 11. Application examples for mobile objects

[0096] 12. Application examples of endoscopic surgery systems

[0097] 13. Appendix

[0098] 1. First Embodiment

[0099] First, a solid-state image pickup device and electronic equipment according to a first embodiment will be described in detail with reference to the drawings.

[0100] 1.1 Electronic equipment

[0101] Figure 1 1 is a block diagram showing a schematic configuration example of an electronic device equipped with a solid-state imaging device according to the first embodiment. Figure 1 As shown, the electronic device 1 includes, for example, an imaging lens 30 , a solid-state imaging device 10 , a storage unit 40 , and a processor 50 .

[0102] The imaging lens 30 is an example of an optical system that collects incident light and forms an image on a light receiving surface of the solid-state imaging device 10. The light receiving surface may be a surface of the solid-state imaging device 10 on which a photoelectric conversion element is arranged. The solid-state imaging device 10 performs photoelectric conversion on the incident light to generate image data. The solid-state imaging device 10 also performs predetermined signal processing such as noise removal and white balance control on the generated image data.

[0103] The storage unit 40 includes, for example, a flash memory, a dynamic random access memory (DRAM), and a static random access memory (SRAM), and records image data and the like input from the solid-state imaging device 10 .

[0104] The processor 50 is configured by using, for example, a central processing unit (CPU), and the processor 50 may include an application processor that executes an operating system and various application software, a graphics processing unit (GPU), a baseband processor, etc. The processor 50 performs various processes on image data input from the solid-state imaging device 10 and image data read from the storage unit 40 as needed, displays the image data to a user, and transmits the image data to the outside via a predetermined network.

[0105] 1.2 Solid-state camera device

[0106] Figure 2 1 is a block diagram showing a schematic configuration example of a CMOS (complementary metal-oxide-semiconductor) type solid-state imaging device (hereinafter referred to as an image sensor) according to a first embodiment. Here, a CMOS type image sensor is an image sensor produced by applying or partially using a CMOS process. In this embodiment, a so-called back-illuminated image sensor 10 in which the surface of a semiconductor substrate opposite to the element forming surface is a light incident surface is illustrated, but this embodiment is not limited to a back-illuminated image sensor, and this embodiment may use a so-called front-illuminated image sensor in which the element forming surface is a light incident surface.

[0107] like Figure 2 As shown, the image sensor 10 includes a SPAD array unit 11 , a timing control circuit 15 , a driving circuit 12 and an output circuit 13 .

[0108] The SPAD array unit 11 includes a plurality of SPAD pixels 20 arranged in a matrix form. For the plurality of SPAD pixels 20, each column is connected to a pixel drive line LD (in the up-down direction in the figure), and each row is connected to an output signal line LS (in the left-right direction in the figure). One end of the pixel drive line LD is connected to an output end of the drive circuit 12 corresponding to each column, and one end of the output signal line LS is connected to an input end of the output circuit 13 corresponding to each row.

[0109] The driving circuit 12 includes a shift register and an address decoder, etc., and the driving circuit 12 drives each SPAD pixel 20 of the SPAD array unit 11 simultaneously or in units of columns, etc. The driving circuit 12 includes at least a circuit for applying the quenching voltage V_QCH described below to each SPAD pixel 20 in a selected column in the SPAD array unit 11, and a circuit for applying the selection control voltage V_SEL described below to each SPAD pixel 20 in the selected column. Then, the driving circuit 12 applies the selection control voltage V_SEL to the pixel drive line LD corresponding to the column to be read to select the SPAD pixel 20 in the column for detecting the incidence of photons.

[0110] The signal (referred to as a detection signal) V_OUT output from each SPAD pixel 20 in the column selected and scanned by the drive circuit 12 is input to the output circuit 13 through each output signal line LS. The output circuit 13 outputs the detection signal V_OUT input from each SPAD pixel 20 to the external storage unit 40 or the processor 50 as a pixel signal.

[0111] The timing control circuit 15 includes a timing generator that generates various timing signals and the like, and the timing control circuit 15 controls the drive circuit 12 and the output circuit 13 based on the various timing signals generated by the timing generator.

[0112] 1.3SPAD pixels

[0113] Figure 3 1 is a circuit diagram showing a schematic configuration example of a SPAD pixel according to the first embodiment. Figure 3 As shown, the SPAD pixel 20 includes a photodiode 21 serving as a light receiving element and a readout circuit 22 for detecting photons incident on the photodiode 21. When photons are incident in a state where a reverse bias voltage V_SPAD equal to or higher than a breakdown voltage is applied between an anode and a cathode, the photodiode 21 generates an avalanche current.

[0114] The readout circuit 22 includes a quenching resistor 23, a digital converter 25, an inverter 26, a buffer 27, and a selection transistor 24. The quenching resistor 23 is, for example, an N-type metal oxide semiconductor field effect transistor (MOSFET) (hereinafter referred to as an NMOS transistor), a drain of which is connected to the anode of the photodiode 21, and a source of which is grounded via the selection transistor 24. In addition, a quenching voltage V_QCH is applied from the drive circuit 12 to the gate of the NMOS transistor constituting the quenching resistor 23 through the pixel drive line LD, and the quenching voltage V_QCH is preset so that the NMOS transistor functions as a quenching resistor.

[0115] In the present embodiment, the photodiode 21 is a SPAD. The SPAD is an avalanche photodiode that operates in a Geiger mode when a reverse bias voltage equal to or higher than a breakdown voltage is applied between its anode and cathode, and is capable of detecting the incidence of one photon.

[0116] The digital converter 25 includes a resistor 251 and an NMOS transistor 252. The drain of the NMOS transistor 252 is connected to the power supply voltage VDD via the resistor 251, and the source is grounded. In addition, the voltage of the connection point N1 between the anode of the photodiode 21 and the quenching resistor 23 is applied to the gate of the NMOS transistor 252.

[0117] The inverter 26 includes a P-type MOSFET (hereinafter referred to as a PMOS transistor) 261 and an NMOS transistor 262. For the PMOS transistor 261, its drain is connected to the power supply voltage VDD, and its source is connected to the drain of the NMOS transistor 262. For the NMOS transistor 262, its drain is connected to the source of the PMOS transistor 261, and its source is grounded. The voltage of the connection point N2 between the resistor 251 and the drain of the NMOS transistor 252 is applied to the gate of the PMOS transistor 261 and the gate of the NMOS transistor 262. The output of the inverter 26 is input to the buffer 27.

[0118] The buffer 27 is a circuit for impedance conversion, and when the output signal is input from the inverter 26 , the buffer 27 performs impedance conversion on the input output signal and outputs it as the detection signal V_OUT.

[0119] The selection transistor 24 is, for example, an NMOS transistor, whose drain is connected to the source of the NMOS transistor constituting the quenching resistor 23 and whose source is grounded. The selection transistor 24 is connected to the drive circuit 12, and when the selection control voltage V_SEL from the drive circuit 12 is applied to the gate of the selection transistor 24 via the pixel drive line LD, the selection transistor 24 changes from the off state to the on state.

[0120] 1.4 Example of General Operation of SPAD Pixel

[0121] For example, Figure 3 The readout circuit 22 shown operates as follows. That is, first, when the selection control voltage V_SEL is applied from the drive circuit 12 to the selection transistor 24 and the selection transistor 24 is in an on state, a reverse bias voltage V_SPAD equal to or higher than a breakdown voltage is applied to the photodiode 21. Thus, the operation of the photodiode 21 is allowed.

[0122] On the other hand, when the selection control voltage V_SEL is not applied from the drive circuit 12 to the selection transistor 24 and the selection transistor 24 is in an off state, the reverse bias voltage V_SPAD is not applied to the photodiode 21 , thus disabling the operation of the photodiode 21 .

[0123] When the selection transistor 24 is in the on state, if a photon is incident on the photodiode 21, an avalanche current is generated in the photodiode 21. As a result, the avalanche current flows through the quenching resistor 23, and the voltage at the connection point N1 increases. When the voltage at the connection point N1 becomes higher than the on voltage of the NMOS transistor 252, the NMOS transistor 252 is in the on state, and the voltage at the connection point N2 changes from the power supply voltage VDD to 0V. When the voltage at the connection point N2 changes from the power supply voltage VDD to 0V, the PMOS transistor 261 changes from the off state to the on state, the NMOS transistor 262 changes from the on state to the off state, and the voltage at the connection point N3 changes from 0V to the power supply voltage VDD. As a result, a high-level detection signal V_OUT is output from the buffer 27.

[0124] After that, as the voltage at the connection point N1 continues to rise, the voltage applied between the anode and cathode of the photodiode 21 becomes lower than the breakdown voltage, causing the avalanche current to stop and the voltage at the connection point N1 to drop. Then, when the voltage at the connection point N1 becomes lower than the voltage of the NMOS transistor 252, the NMOS transistor 252 is in the off state, and the output of the detection signal V_OUT (low level) from the buffer 27 stops.

[0125] In this way, the readout circuit 22 outputs a high-level detection signal V_OUT in a period from the time when photons are incident on the photodiode 21 to generate an avalanche current (which turns the NMOS transistor 252 on) to the time when the avalanche current stops (which turns the NMOS transistor 252 off). The output detection signal V_OUT is input to the output circuit 13.

[0126] 1.5 Example of color filter layout

[0127] As described above, a color filter that selectively transmits light of a specific wavelength is arranged in the photodiode 21 of each SPAD pixel 20 . Figure 4 is a diagram showing an example of a color filter layout according to the first embodiment.

[0128] like Figure 4 As shown, the color filter array 60 has, for example, a configuration in which patterns (hereinafter referred to as unit patterns) 61 as repeating units of the color filter array are arranged in a two-dimensional lattice pattern.

[0129] Each unit pattern 61 has a so-called Bayer array structure consisting of a total of 4 color filters, which include, for example, a color filter 115R that selectively transmits light having a red (R) wavelength component, two color filters 115G that selectively transmit light having a green (G) wavelength component, and a color filter 115B that selectively transmits light having a blue (B) wavelength component.

[0130] Note that in the present disclosure, the color filter array 60 is not limited to the Bayer array. For example, various color filter arrays can be adopted, such as an X-Trans (registered trademark) type color filter array with 3×3 pixels as a unit pattern, a quad Bayer array with 4×4 pixels, and a white RGB type color filter array with 4×4 pixels, which includes color filters of the three primary colors of RGB and a color filter having a wide light transmission characteristic for the visible light region (hereinafter also referred to as a transparent filter or a white filter).

[0131] 1.6 Example of stacked structure of solid-state imaging device

[0132] Figure 5 1 is a diagram showing an example of a stacked structure of an image sensor according to the first embodiment. Figure 5 As shown in FIG. 1 , the image sensor 10 has a structure in which a light receiving chip 71 and a circuit chip 72 are stacked on each other. The light receiving chip 71 is, for example, a semiconductor chip including a SPAD array unit 11 in which a photodiode 21 is arranged, and the circuit chip 72 is, for example, a semiconductor chip in which a SPAD array unit 11 is arranged. Figure 3 The semiconductor chip of the readout circuit 22 shown in FIG. 7A and 7B may be provided with peripheral circuits such as the timing control circuit 15, the drive circuit 12, and the output circuit 13.

[0133] In order to bond the light receiving chip 71 and the circuit chip 72, for example, so-called direct bonding can be used, in which each bonding surface is flattened and the two are bonded by electron inter-force. However, bonding is not limited to this, and for example, so-called Cu-Cu bonding or bump bonding can also be used, in which copper (Cu) electrode pads formed on the bonding surfaces of the chips are bonded together.

[0134] In addition, the light receiving chip 71 and the circuit chip 72 are electrically connected through a connection portion such as a through silicon via (TSV) penetrating the semiconductor substrate. For connection using TSV, for example, the following methods can be adopted: a so-called double TSV method in which two TSVs, a TSV provided in the light receiving chip 71 and a TSV provided from the light receiving chip 71 to the circuit chip 72, are connected on the outer surface of the chip; or a so-called shared TSV method in which the two chips are connected through a TSV penetrating from the light receiving chip 71 to the circuit chip 72.

[0135] However, in the case of bonding the light receiving chip 71 and the circuit chip 72 using Cu-Cu bonding or bump bonding, the chips are electrically connected through the Cu-Cu bonding portion or the bump bonding portion.

[0136] 1.7 Example of a cross-sectional structure of a SPAD pixel

[0137] Figure 6 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of the SPAD pixel according to the first embodiment. Figure 7 It shows Figure 6 A horizontal cross-sectional view of an example of a cross-sectional structure of plane AA in FIG. Note that Figure 6 Focus is placed on the cross-sectional structure of the photodiode 21 .

[0138] like Figure 6 As shown, for example, the photodiode 21 of the SPAD pixel 20 is provided in the semiconductor substrate 101 constituting the light receiving chip 71. The semiconductor substrate 101 is divided into a plurality of element regions by the element separation unit 110 formed in a grid shape as viewed from the light incident surface (see Figure 7 ). Photodiodes 21 are respectively provided in element regions divided by the element separation unit 110. Note that the element separation unit 110 may include an anode electrode 122 and an insulating film 109 in a first trench which will be described below.

[0139] Each photodiode 21 includes a photoelectric conversion region 102 , a P-type semiconductor region 104 , an N− type semiconductor region 103 , a P+ type semiconductor region 105 , an N+ type semiconductor region 106 , a cathode contact 107 , and an anode contact 108 .

[0140] The photoelectric conversion region 102 is, for example, an N-type well region or a region containing a low-concentration donor, and performs photoelectric conversion on incident light to generate electron-hole pairs (hereinafter referred to as charges).

[0141] The P-type semiconductor region 104 is, for example, a region including a P-type acceptor, and Figure 6 and Figure 7 As shown, the P-type semiconductor region 104 is provided in a region surrounding the photoelectric conversion region 102. When a reverse bias voltage V_SPAD is applied to an anode contact 108 described later, the P-type semiconductor region 104 forms an electric field for guiding charges generated in the photoelectric conversion region 102 to the N-type semiconductor region 103.

[0142] The N-type semiconductor region 103 is, for example, a region containing a donor, the concentration of which is higher than the concentration of the donor in the photoelectric conversion region 102. Figure 6 and Figure 7 As shown, the N-type semiconductor region 103 is arranged in the central portion of the photoelectric conversion region 102, and absorbs charges generated in the photoelectric conversion region 102 and guides them to the P+ type semiconductor region 105. Note that the N-type semiconductor region 103 is not an essential component and can be omitted.

[0143] The P+ type semiconductor region 105 is, for example, a region including an acceptor whose concentration is higher than that of the P type semiconductor region 104 and partially contacts the P type semiconductor region 104. In addition, the N+ type semiconductor region 106 is, for example, a region including a donor whose concentration is higher than that of the N- type semiconductor region 103 and contacts the P+ type semiconductor region 105.

[0144] These P+ type semiconductor region 105 and N+ type semiconductor region 106 form a PN junction and function as an amplification region that accelerates the inflowing charges to generate an avalanche current.

[0145] The cathode contact 107 is, for example, a region including a donor having a higher concentration than that of the donor in the N+ type semiconductor region 106 and is provided in a region in contact with the N+ type semiconductor region 106 .

[0146] The anode contact 108 is, for example, a region containing an acceptor having a concentration higher than that of the acceptor in the P+ type semiconductor region 105. The anode contact 108 is provided in a region in contact with the periphery of the P type semiconductor region 104. The width of the anode contact 108 may be, for example, about 40 nm (nanometers). The anode contact 108 is in contact with the entire periphery of the P type semiconductor region 104 in such a manner that a uniform electric field can be formed in the photoelectric conversion region 102.

[0147] In addition, if Figure 6 and Figure 7 As shown, the anode contact 108 is provided on the lower surface (hereinafter referred to as the first groove) of the groove provided in a lattice pattern along the element separation unit 110 on the front side (lower surface in the figure) of the semiconductor substrate 101. Due to such a structure, as described below, the position where the anode contact 108 is formed is offset in the height direction from the position where the cathode contact 107 and the N+ type semiconductor region 106 are formed.

[0148] The front (lower surface in the figure) side of the semiconductor substrate 101 is covered with an insulating film 109. The film thickness (thickness in the substrate width direction) of the insulating film 109 in the first trench depends on the voltage value of the reverse bias V_SPAD applied between the anode and the cathode, but can be, for example, about 150 nm.

[0149] The insulating film 109 has openings on the front surface of the semiconductor substrate 101 to expose the cathode contact 107 and the anode contact 108. The openings are provided with a cathode electrode 121 in contact with the cathode contact 107 and an anode electrode 122 in contact with the anode contact 108, respectively.

[0150] The element separation unit 110 that divides the semiconductor substrate 101 into the photodiodes 21 is provided in a groove (hereinafter referred to as a second groove) that penetrates from the front to the back of the semiconductor substrate 101. The second groove is connected to the first groove on the front side of the semiconductor substrate 101. The inner dimension of the second groove is shorter than the inner dimension of the first groove, and the anode contact 108 is provided at the stepped portion formed thereby.

[0151] Each element separation unit 110 includes an insulating film 112 covering the inner surface of the second groove and a light shielding film 111 filling the inside of the second groove. The film thickness of the insulating film 112 (thickness in the substrate width direction) depends on the voltage value of the reverse bias V_SPAD applied between the anode and the cathode, but can be, for example, about 10nm to 20nm. In addition, the film thickness of the light shielding film 111 (thickness in the substrate width direction) depends on the material used for the light shielding film 111, but can be, for example, about 150nm.

[0152] Here, by using a conductive material having a light-shielding property for the light-shielding film 111 and the anode electrode 122, the light-shielding film 111 and the anode electrode 122 can be formed in the same process. In addition, by using the same conductive material as that of the light-shielding film 111 and the anode electrode 122 for the cathode electrode 121, the light-shielding film 111, the anode electrode 122, and the cathode electrode 121 can also be formed in the same process.

[0153] As such a conductive material having a light-shielding property, tungsten (W) or the like can be used. However, the conductive material is not limited to tungsten (W), and can be changed with various materials such as aluminum (Al), aluminum alloy, and copper (Cu) as long as it is a conductive material having the property of reflecting or absorbing visible light or light required for each element.

[0154] However, the material of the light shielding film 111 in the second trench is not limited to a conductive material and can be, for example, a high refractive index material having a higher refractive index than the semiconductor substrate 101 or a low refractive index material having a lower refractive index than the semiconductor substrate 101 .

[0155] In addition, since the material used for the cathode electrode 121 does not need to have a light-shielding property, a conductive material such as copper (Cu) may be used instead of a conductive material having a light-shielding property.

[0156] Note that in this embodiment, although the so-called front surface full trench isolation (FFTI) type element separation unit 110 that penetrates the semiconductor substrate 101 from the front surface side is used as an example of the second trench, the second trench is not limited to this, and the following structures can be used as the second trench: a full trench isolation (FTI) type element separation unit that penetrates the semiconductor substrate 101 from the back side and / or the front surface side; or a deep trench isolation (DTI) type or reverse deep trench isolation (RDTI) type element separation unit that is formed from the front surface or back side of the semiconductor substrate 101 to the middle.

[0157] When the second trench is of the FTI type penetrating the semiconductor substrate 101 from the back side, the material of the light shielding film 111 can be inserted into the second trench from the back side of the semiconductor substrate 101 .

[0158] The upper portions of the cathode electrode 121 and the anode electrode 122 protrude toward the front surface (lower surface in the figure) of the insulating film 109. On the front surface (lower surface in the figure) of the insulating film 109, for example, a wiring layer 120 is provided.

[0159] The wiring layer 120 includes an interlayer insulating film 123 and wiring 124 provided in the interlayer insulating film 123. The wiring 124 is in contact with, for example, a cathode electrode 121 protruding from the front surface (lower surface in the figure) of the insulating film 109. Note that the wiring layer 120 is also provided with wiring in contact with the anode electrode 122, although Figure 6 It is omitted in .

[0160] On the front surface (lower surface in the figure) of the wiring layer 120, a connection pad 125 made of, for example, copper (Cu) is exposed. The connection pad 125 may be a part of the wiring 124. In this case, the wiring 124 is also made of copper (Cu).

[0161] The wiring layer 130 in the circuit chip 72 is connected to the front surface of the wiring layer 120. The wiring layer 130 includes an interlayer insulating film 131 and wirings 132 provided in the interlayer insulating film 131. The wirings 132 are electrically connected to a circuit element 142 (e.g., a readout circuit 22) formed on the semiconductor substrate 141. Thus, the cathode electrode 121 of the semiconductor substrate 101 is connected to the front surface of the wiring layer 120 via the wirings 124, the connection pads 125 and 135, and the wirings 132. Figure 3 The readout circuit 22 is shown.

[0162] In addition, a connection pad 135 made of, for example, copper (Cu) is exposed on the front surface (upper surface in the figure) of the wiring layer 130. By bonding the connection pad 135 to the connection pad 125 exposed on the surface of the wiring layer 120 of the light receiving chip 71 (Cu-Cu bonding), the light receiving chip 71 and the circuit chip 72 are electrically and mechanically connected.

[0163] The connection pad 135 may be a part of the wiring 132. In this case, the wiring 132 is also made of copper (Cu).

[0164] Furthermore, a pinning layer 113 and a planarization film 114 are provided on the back surface (upper surface in the figure) of the semiconductor substrate 101. Furthermore, on the planarization film 114, a color filter 115 and an on-chip lens 116 are provided for each SPAD pixel 20.

[0165] The pinning layer 113 is a fixed charge film composed of, for example, a hafnium oxide (HfO2) film or an aluminum oxide (Al2O3) film containing a predetermined concentration of acceptors. The planarization film 114 is an insulating film made of an insulating material such as silicon oxide (SiO2) and silicon nitride (SiN), and is a film for planarizing the surface on which the upper color filter 115 and the on-chip lens 116 are to be formed.

[0166] In the above structure, when a reverse bias voltage V_SPAD equal to or higher than the breakdown voltage is applied between the cathode contact 107 and the anode contact 108, an electric field is formed that guides the charges generated in the photoelectric conversion region 102 to the N-type semiconductor region 103 due to the potential difference between the P-type semiconductor region 104 and the N+ type semiconductor region 106. In addition, a strong electric field is formed in the PN junction region between the P+ type semiconductor region 105 and the N+ type semiconductor region 106 to accelerate the inflowing charges and generate an avalanche current. As a result, the photodiode 21 can operate as an avalanche photodiode.

[0167] 1.8 Positional Relationship Between Anode Contact and Cathode Contact and / or N+ Type Semiconductor Region

[0168] Next, the positional relationship between the anode contact 108 and the cathode contact 107 and / or the N + -type semiconductor region 106 in the present embodiment will be described.

[0169] As described above, in the present embodiment, the anode contact 108 is arranged at the bottom of the first trench formed on the front surface side of the semiconductor substrate 101. Therefore, in the present embodiment, the anode contact 108 is arranged at a position deeper than the cathode contact 107 and the N+ type semiconductor region 106 from the front surface (the lower surface in the figure) of the semiconductor substrate 101. That is, in the present embodiment, with the front surface (the lower surface in the figure) of the semiconductor substrate 101 used as a reference, the position where the anode contact 108 is formed is shifted in the height direction from the position where the cathode contact 107 and the N+ type semiconductor region 106 are formed.

[0170] In other words, the height of the anode contact 108 from the front surface of the semiconductor substrate 101 is different from the height of the N+ type semiconductor region 106 from the front surface of the semiconductor substrate 101. In a specific example, the height of the anode contact 108 from the front surface of the semiconductor substrate 101 is longer than the height of the N+ type semiconductor region 106 from the front surface of the semiconductor substrate 101.

[0171] In this way, since the position at which the anode contact 108 is formed and the position at which the cathode contact 107 and the N+ type semiconductor region 106 are formed are staggered from each other in the height direction, the distance from the anode contact 108 to the cathode contact 107 and / or the N+ type semiconductor region 106 can be extended without increasing the size of the SPAD pixel 20 in the lateral direction (the direction parallel to the incident surface).

[0172] As a result, since the occurrence of the tunnel effect can be suppressed without increasing the pixel size, avalanche amplification can be generated in a stable manner while suppressing a decrease in resolution.

[0173] 1.9 Manufacturing method

[0174] Next, a method for manufacturing the image sensor 10 according to the present embodiment will be described in detail with reference to the drawings. Note that in the following description, attention will be paid to a method for manufacturing the light receiving chip 71.

[0175] Figures 8 to 20 1 is a process cross-sectional view showing a method of manufacturing the solid-state image pickup device according to the first embodiment.

[0176] In this manufacturing method, first, Figure 8 As shown, donor and acceptor ions are implanted into a predetermined region of a semiconductor substrate 101 completely containing low-concentration donors to form a portion of a P-type semiconductor region 104 (P-type semiconductor region 104a) that divides a photoelectric conversion region 102, an N-type semiconductor region 103, a P+ type semiconductor region 105, and an N+ type semiconductor region 106. Note that, for example, ion implantation can be performed from the front surface (upper surface in the figure) of the semiconductor substrate 101. In addition, after the ion implantation, one or more annealings for damage recovery during ion implantation and improvement of the profile of the implanted dopant can be performed.

[0177] Then, if Fig. 9As shown, a mask M1 having a lattice-shaped opening A1 is formed on the front surface of the semiconductor substrate 101, and the semiconductor substrate 101 is engraved from the upper side of the mask M1 by anisotropic dry etching such as reactive ion etching (RIE: reactive ion etching) to form a lattice-shaped first trench T1 along the boundary portion with the adjacent SPAD pixel 20. Note that the depth of the first trench T1 can be long enough so that its bottom surface is located at a deeper level than the lower surface of the P+ type semiconductor region 105 and reaches the P type semiconductor region 104a.

[0178] Note that the longer the depth of the first trench T1 from the front surface of the semiconductor substrate 101, the longer the distance from the anode contact 108 to the N+ type semiconductor region 106 and the cathode contact 107, which is preferred. However, if the first trench T1 is too deep, the process accuracy may be reduced and the yield rate may be reduced. Therefore, the depth of the first trench T1 should be set within a range that can ensure higher than necessary process accuracy.

[0179] Then, if Fig.10 As shown, after removing the mask M1, an insulating film 109A covering the front surface of the semiconductor substrate 101 and the inside of the first trench T1 is formed by using a film forming technique such as sputtering and chemical vapor deposition (CVD). Note that for the insulating film 109A, insulating materials such as silicon oxide (SiO2), silicon nitride (SiN), silicon carbide (SiC) and aluminum oxide (Al2O3) can be used. In addition, the insulating film 109A can have a single-layer structure or a stacked structure. As described above, since a high reverse bias V_SPAD is applied to the anode electrode 122, the insulating film 109A must have a high withstand voltage performance. In view of this requirement, it is preferred to use an insulating material with a high withstand voltage performance such as silicon oxide (SiO2) as the material of the insulating film 109A.

[0180] Then, if Fig.11 As shown, the bottom surface of the trench T11 formed by the surface of the insulating film 109A in the first trench T1 is engraved in the substrate thickness direction to form a second trench T2 from the front surface side to the vicinity of the back surface of the semiconductor substrate 101. Note that in order to form the second trench T2, for example, anisotropic dry etching capable of obtaining a sufficiently high selectivity for the semiconductor substrate 101 can be used. Therefore, while using the insulating film 109A formed on the inner surface of the first trench T1 and the upper surface of the semiconductor substrate 101 as a mask, the lattice-shaped region of the semiconductor substrate 101 where the element separation unit 110 is to be formed can be etched.

[0181] Then, if Fig.12As shown, the insulating film 109A in the first trench T1 is thinned by isotropic etching such as wet etching to expose the outer peripheral portion of the P-type semiconductor region 104a at the bottom of the first trench T1. At this time, the insulating film 109A on the front surface of the semiconductor substrate 101 can be thinned.

[0182] Then, if Fig.13 As shown, a mask M2 having an opening A2 is formed on the insulating film 109A and located above the N+ type semiconductor region 106, and the insulating film 109A is etched from the upper side of the mask M2 by anisotropic dry etching such as RIE to form an opening A3 that exposes a portion of the upper surface of the semiconductor substrate 101.

[0183] Then, if Fig.14 As shown, after removing the mask M2, an insulating film 109B is isotropically formed to cover the surface of the insulating film 109A, the inner side surface and bottom surface of the opening A3, and the inner side surfaces of the first trench T1 and the second trench T2 by using a film forming technique such as a CVD method. In the following description, the insulating film 109A and the insulating film 109B are collectively referred to as an insulating film 109. In addition, a trench formed by the surface of the insulating film 109B in the opening A3 is referred to as a trench T4, and a trench formed by the surface of the insulating film 109B in the trench T3 is referred to as a trench T5.

[0184] When the insulating film 109B is omitted, as will be described in detail in the first modification example below, the anode electrode 122 and the P-type semiconductor region 104a can contact each other in the second trench T2 and the anode contact 108, thereby achieving a contact with low resistance.

[0185] On the other hand, when the insulating film 109B is formed, damage to the semiconductor substrate 101 due to ion implantation during contact formation described below can be reduced.

[0186] Then, if Fig.15 As shown, a mask M3 covering the trench T4 is formed above the N+ type semiconductor region 106, and acceptors are ion-implanted at a high concentration from the upper side of the mask M3 and the insulating film 109. At this time, the mask M3 and the insulating film 109 are used as masks so that the anode contact 108 containing a high concentration of acceptors is formed at the bottom of the trench T5, which is a region where the thickness of the insulating film 109 is small, in other words, the upper periphery of the P type semiconductor region 104 (for example, see Figure 7 ).

[0187] Then, if Fig.16As shown, after removing the mask M3, for example, a mask M4 is formed to cover the trench T5 formed in a lattice pattern, and acceptors are ion-implanted at a high concentration from the upper side of the mask M4 and the insulating film 109. At this time, the mask M4 and the insulating film 109 are used as masks so that the cathode contact 107 containing a high concentration of donors is formed at the bottom of the trench T4, which is a region where the thickness of the insulating film 109 is small, in other words, a portion of the semiconductor substrate 101 located on the N+ type semiconductor region 106.

[0188] Note that for the formation of the anode contact 108 and the cathode contact 107, not only the ion implantation method but also various methods such as solid phase diffusion and plasma doping can be used.

[0189] Then, if Fig.17 As shown, after removing the mask M4, the insulating film 109 at the bottom of the trench T4 is removed to expose the cathode contact 107, and the insulating film 109 at the bottom of the trench T5 is removed to expose the anode contact 108, for example, by etching back the entire surface of the insulating film 109.

[0190] At this time, the details of which will be described in the second modification example described below, by forming a mask having a predetermined opening pattern by photolithography or the like, the region where the insulating film 109 is removed and the anode contact 108 is exposed can be limited.

[0191] When the entire surface of the insulating film 109 is etched back, the contact area between the anode contact 108 and the anode electrode 122 can be ensured, so that a low-resistance contact can be formed. In addition, since the anode contact 108 and the anode electrode 122 can be brought into contact with each other to surround the periphery of the P-type semiconductor region 104a, a uniform electric field can be formed in the photoelectric conversion region 102.

[0192] On the other hand, when the area where the insulating film 109 is removed is limited, the contact portion between the anode contact 108 and the anode electrode 122 can be adjusted, so that the distribution of the electric field formed in the photoelectric conversion region 102 can be controlled.

[0193] Note that in this embodiment, the insulating film 109 remaining in the second trench T2 after the insulating film 109 is thinned is used as the insulating film 112 of the element separation unit 110 .

[0194] Subsequently, a titanium (Ti) / titanium nitride (TiN) film, for example, is formed on the exposed surfaces of the cathode contact 107 and the anode contact 108, and annealing is performed in this state at about 500° C. to 800° C. As a result, silicon (Si) and titanium (Ti) react with each other on the exposed surfaces of the cathode contact 107 and the anode contact 108 to form a titanium silicide layer.

[0195] By forming silicide on the surfaces (contact surfaces) of the cathode contact 107 and the anode contact 108 in this way, the contact between the cathode contact 107 and the cathode electrode 121 and the contact between the anode contact 108 and the anode electrode 122 can be ohmic contacts. Therefore, the resistance of those connections can be reduced. As a result, since the contact area between the anode contact 108 and the anode electrode 122 can be reduced, the pixel size can be reduced, and the resolution can be increased.

[0196] Note that a Co / TiN film may be used instead of a Ti / TiN film. Even in this case, since a cobalt silicide layer is formed on the surface (contact surface) of the cathode contact 107 and the anode contact 108, the cathode contact 107 and the cathode electrode 121 and the anode contact 108 and the anode electrode 122 can also be in ohmic contact.

[0197] In addition, by using various silicides such as nickel silicide instead of titanium silicide and cobalt silicide, the cathode contact 107 and the cathode electrode 121 and the anode contact 108 and the anode electrode 122 can be in ohmic contact.

[0198] Then, if Fig.18 As shown, by using a lift-off method or the like, a light shielding film 111 is formed in the first trench T1, a cathode electrode 121 in contact with the cathode contact 107 is formed in the trench T4, and an anode electrode 122 in contact with the anode contact 108 is formed in the second trench T2.

[0199] As described above, the materials of the light shielding film 111, cathode electrode 121 and anode electrode 122 can be various conductive materials such as aluminum (Al), aluminum alloy and copper (Cu) having the property of reflecting or absorbing visible light or light required for each element, instead of tungsten (W).

[0200] When the light shielding film 111, the cathode electrode 121, and the anode electrode 122 are made of the same material, they can be formed at the same time. On the other hand, when the light shielding film 111, the cathode electrode 121, and the anode electrode 122 are made of different materials, the light shielding film 111 is formed first, and then the cathode electrode 121 and the anode electrode 122 are formed by a lift-off method or the like.

[0201] Subsequently, on the insulating film 109 on which the cathode electrode 121 and the anode electrode 122 are formed, a wiring layer 120 including a wiring 124 connected to the cathode electrode 121, a wiring 126 connected to the anode electrode 122, and an interlayer insulating film 123 is formed. In addition, connection pads 125 and 127 made of copper (Cu) exposed on the surface of the interlayer insulating film 123 are formed.

[0202] Then, if Fig.19As shown, the semiconductor substrate 101 is thinned from the back side so that the second trench T2 penetrates, so that the light shielding film 111 in the second trench T2 reaches the back side of the semiconductor substrate 101. To thin the semiconductor substrate 101, chemical mechanical polishing (CMP) or the like can be used.

[0203] Then, acceptor ions are implanted into the entire back surface of the semiconductor substrate 101. As a result, Fig. 20 As shown, the P-type semiconductor region 104 surrounding the photoelectric conversion region 102 is completed.

[0204] Thereafter, a pinning layer 113, a planarization film 114, a color filter 115, and an on-chip lens 116 are sequentially formed on the back surface of the semiconductor substrate 101 to form a light receiving chip 71 in the image sensor 10. Then, by bonding the separately prepared circuit chip 72 and the light receiving chip 71 to each other, a semiconductor device having a semiconductor substrate 101 is manufactured. Figure 6 The cross-sectional structure of the image sensor 10 is shown.

[0205] 1.10 Effect

[0206] As described above, in the present embodiment, the position of the anode contact 108 and the position of the cathode contact 107 and / or the N+ type semiconductor region 106 are offset in the height direction. Therefore, according to the present embodiment, the distance from the anode contact 108 to the cathode contact 107 and / or the N+ type semiconductor region 106 can be extended without increasing the size in the lateral direction (direction parallel to the incident surface) of the SPAD pixel 20. As a result, since the generation of the tunnel effect can be suppressed without increasing the pixel size, avalanche amplification can be generated in a stable manner while suppressing a reduction in resolution.

[0207] 1.11 Modification

[0208] Next, several specific modifications of the SPAD pixel 20 according to the first embodiment will be described.

[0209] 1.11.1 First Modification

[0210] Fig.21 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to a first modification.

[0211] like Fig.21 As shown, in the SPAD pixel 20a according to the first modification, in the same manner as in the first embodiment, Figure 6 In the structure similar to the cross-sectional structure described in FIG. 1 and FIG. 2 , the insulating film 112 (corresponding to the insulating film 109B) in the second trench (corresponding to the second trench T2 ) is omitted.

[0212] As described in the first embodiment, by omitting the insulating film 112 in the element separation unit 110 in this way, the anode electrode 122 and the P-type semiconductor region 104 can be brought into contact with each other in the second trench and the anode contact 108 , thereby enabling a contact with low resistance.

[0213] 1.11.2 Second Modification

[0214] Fig. 22 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a second modification. Note that Fig. 22 Shown with Figure 7 The surface corresponding to the surface in .

[0215] like Fig. 22 As shown, in the SPAD pixel 20b according to the second modification, in comparison with the first embodiment, Figure 7 In a structure similar to the cross-sectional structure described in the examples above, the formation region of the anode contact 108A is limited so that the anode contact 108A contacts a portion of the outer periphery of the P-type semiconductor region 104. In a specific example, the formation region of the anode contact 108A is limited to the four corners of a rectangular region divided by the element separation unit 110.

[0216] As described in the first embodiment, by limiting the formation region of the anode contact 108A in this way, the contact portion between the anode contact 108 and the anode electrode 122 can be adjusted, thereby controlling the distribution of the electric field formed in the photoelectric conversion region 102 .

[0217] 1.11.3 Third variant

[0218] Fig.23 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to a third modification example.

[0219] like Fig.23 As shown, in the SPAD pixel 20c according to the third modification, in the same manner as in the first embodiment, Figure 6 In a structure similar to the cross-sectional structure described in , etc., the P+ type semiconductor region 105A and the N+ type semiconductor region 106A extend to contact the insulating film 109 formed in the first trench.

[0220] By extending the P+ type semiconductor region 105A and the N+ type semiconductor region 106A in the entire region sandwiched between the first trenches in this manner, the region where avalanche amplification occurs can be expanded, thereby improving quantum efficiency.

[0221] Furthermore, by extending the P+ semiconductor region 105A throughout the entire region between the first trenches, it is possible to prevent charges generated near the anode contact 108 from directly flowing into the N+ semiconductor region 106A or the cathode contact 107. Therefore, the amount of charges that do not contribute to avalanche amplification can be reduced, and quantum efficiency can be improved.

[0222] 1.11.4 Fourth variant

[0223] Fig.24 : is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to a fourth modification.

[0224] like Fig.24 As shown, in the SPAD pixel 20d according to the fourth modification, in comparison with the first embodiment, Figure 6 In the structure similar to the cross-sectional structure described in the examples above, by extending the first trench, the insulating film 109D in the first trench is widened to a degree that it contacts at least the P + -type semiconductor region 105A.

[0225] In this way, by extending the first trench so that the insulating film 109D contacts the P+ type semiconductor region 105A, it is possible to prevent the charges generated near the anode contact 108 from directly flowing into the N+ type semiconductor region 106A or the cathode contact 107. Therefore, the amount of charges that do not contribute to avalanche amplification can be reduced, and the quantum efficiency can be improved.

[0226] 1.11.5 Fifth variant

[0227] In the fifth modification, several examples of connection wiring to the anode in the above-described embodiment and its modification will be given. Note that in the following description, for the sake of simplicity, the case based on the first embodiment will be shown.

[0228] Fig.25 1 is a diagram showing an example of connection wiring to an anode according to the first embodiment. Fig.25 As shown, in the first embodiment, the wiring 152 for applying the reverse bias voltage V_SPAD is connected to the anode electrode 122 of each SPAD pixel 20 in a one-to-one manner.

[0229] However, for example, as can be seen Figure 7 It can be seen that the anode electrode 122 is continuous in the plurality of SPAD pixels 20. For example, all the SPAD pixels 20 arranged in the SPAD array unit 11 are electrically connected.

[0230] Therefore, it is not necessary to provide the wiring 152 for the anode electrode 122 of each SPAD pixel 20 on a one-to-one basis.

[0231] For example, by Fig.26 As shown in FIG. 1 , wiring 152 is provided for every other SPAD pixel 20, or by Fig. 27 As shown, by providing the wiring 152 every three SPAD pixels 20 , the number of wirings 152 can be reduced.

[0232] Alternatively, if Fig.28 As shown, a configuration may be used in which the wiring 152 is provided for at least one of the SPAD pixels 20Z located at the outermost periphery of the SPAD array unit 11 and the wiring 152 is not provided for the other SPAD pixels 20 and 20Z.

[0233] By reducing the number of wirings 152 in this way, the wiring pattern can be simplified, so that simplification of the manufacturing process and reduction of the manufacturing cost can be achieved.

[0234] Note that although the case where the cathode is N type and the anode is P type has been shown in the above-mentioned embodiment and its modified example, the combination is not limited to this and can be modified in various ways, such as the case where the cathode is P type and the anode is N type.

[0235] 2. Second Embodiment

[0236] A solid-state imaging device and electronic equipment according to a second embodiment will be described in detail below with reference to the drawings.

[0237] For example, the SPAD pixels 20, 20a, 20b, 20c and 20d according to the above-mentioned first embodiment and its modified examples can be used not only in the electronic device 1 used as a camera device for acquiring image data such as color images, but also in an electronic device used as a distance measuring device for measuring the distance to an object.

[0238] Fig.29 1 is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to the second embodiment. Fig.29 As shown, the SPAD pixel 220 has the following structure: Figure 6 In the structure with a similar cross-sectional structure as described in the examples above, the color filter 115 is omitted.

[0239] Even in the case where the SPAD pixel 220 is used for an electronic device used as a distance measuring device and in the first embodiment, since the position of the anode contact 108 and the position of the cathode contact 107 and / or the N+ type semiconductor region 106 are offset in the height direction, the distance from the anode contact 108 to the cathode contact 107 and / or the N+ type semiconductor region 106 can be extended without increasing the size in the lateral direction (direction parallel to the incident surface) of the SPAD pixel 220. As a result, since the generation of the tunnel effect can be suppressed without increasing the pixel size, avalanche amplification can be generated in a stable manner while suppressing a reduction in resolution.

[0240] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0241] 3. Third embodiment

[0242] Next, a solid-state image pickup device and electronic equipment according to a third embodiment will be described in detail with reference to the drawings.

[0243] In the above-described embodiment and its modified examples, although the FFTI type element separation unit 110 in which the second trench penetrates from the front surface side to the back surface side of the semiconductor substrate 101 is exemplified, the element separation unit 110 is not limited to the FFTI type one as described above.

[0244] Fig.30 1 is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to the third embodiment. Fig.30 As shown, the SPAD pixel 320 has the following structure: Figure 6 In a structure with a similar cross-sectional structure as described in the examples above, the FFTI type element separation unit 110 is replaced by a DTI type element separation unit 310 .

[0245] The DTI type element separation unit 310 includes an insulating film 312 covering the inner surface and bottom surface of the second groove and a shading film 311 in a second groove formed in a manner not reaching the back side from the front surface side (the lower surface side in the figure) of the semiconductor substrate 101, and the interior of the second groove whose inner surface is covered by the insulating film 312 is filled with the shading film 311.

[0246] Such an element separation unit 310 can be realized, for example, by forming a shallow second trench or by using a thick semiconductor substrate 101 .

[0247] In this way, according to the present embodiment, the DTI type element separation unit 310 formed from the front surface side of the semiconductor substrate 101 is used. This can facilitate the thinning process of the semiconductor substrate 101 from the back surface side.

[0248] Furthermore, by using the DTI type element separation unit 310 formed from the front surface side of the semiconductor substrate 101, the P-type semiconductor region 104 is not separated on the back surface side of the semiconductor substrate 101 for each SPAD pixel 320. As a result, the change in the electric field distribution pattern in each SPAD pixel 320 due to the change in the contact resistance between the P-type semiconductor region 104 and the anode contact 108 is suppressed, and the electric field in each SPAD pixel 320 is leveled. Therefore, the yield rate of the image sensor 10 can be improved.

[0249] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0250] 4. Fourth embodiment

[0251] Next, a solid-state image pickup device and electronic equipment according to a fourth embodiment will be described in detail with reference to the drawings.

[0252] Fig.31 1 is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to a fourth embodiment. Fig.31 As shown, the SPAD pixel 420 has, for example, the following structure: Fig.30 In a structure similar to the described SPAD pixel 320, the anode contact 408 is provided at the bottom of the second trench.

[0253] According to this structure, the light shielding film 311 electrically connected to the anode electrode 122 is electrically connected to the P-type semiconductor region 104 on the back side of the semiconductor substrate 101 via the anode contact 408 at the bottom of the second trench. As a result, since the contact resistance between the P-type semiconductor region 104 and the anode contact 108 can be further reduced and the change in the contact resistance can be suppressed, the change in the electric field distribution mode in each SPAD pixel 320 can be further suppressed. As a result, since the electric field in each SPAD pixel 320 is further leveled, the yield rate of the image sensor 10 can be further improved.

[0254] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0255] 5. Fifth embodiment

[0256] Next, a solid-state image pickup device and electronic equipment according to a fifth embodiment will be described in detail with reference to the drawings.

[0257] In the third and fourth embodiments described above, the DTI type element separation unit 310 formed in the second groove from the front surface side of the semiconductor substrate 101 has been exemplified. On the other hand, in the fifth embodiment, the RDTI type element separation unit formed in the second groove from the back surface side of the semiconductor substrate 101 is exemplified.

[0258] Fig.32 1 is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to a light incident surface of a SPAD pixel according to a fifth embodiment. Fig.32 As shown, the SPAD pixel 520 has, for example, the following structure: Fig.30 In the structure with a similar cross-sectional structure described, the FFTI type element separation unit 110 is replaced with the RDTI type element separation unit 510, and the anode contact 108 is replaced with the anode contact 508.

[0259] The RDTI type element separation unit 510 includes an insulating film 512 covering the inner surface and bottom surface of the second groove and a shading film 511 in a second groove formed in a manner not reaching the front surface from the back side (upper surface side in the figure) of the semiconductor substrate 101, and the interior of the second groove whose inner surface is covered by the insulating film 512 is filled with the shading film 511.

[0260] According to this structure, since the anode electrode 122 and the element separation unit 520 are separated, the anode contact 508 can be formed on the entire back surface of the anode electrode 122. As a result, since the contact resistance between the P-type semiconductor region 104 and the anode contact 108 can be further reduced, a SPAD pixel 520 with better characteristics can be realized.

[0261] Furthermore, since the second trench can be formed from the back surface side of the semiconductor substrate 101 , the formation process of the element separation unit 520 can be further simplified compared to the case of forming the DTI type element separation unit 310 according to the third or fourth embodiment.

[0262] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0263] 6. Sixth embodiment

[0264] Next, a solid-state image pickup device and electronic equipment according to a sixth embodiment will be described in detail with reference to the drawings.

[0265] In the above-described embodiment and its modified example, for example, a case is shown where one photodiode 21 is provided for each color filter 115R, 115G, and 115B of the color filter array 60 constituting the Bayer array. However, in the case of photon counting using an avalanche photodiode, even when a plurality of photons are incident on one photodiode 21 during one avalanche amplification, the incidence of the photons is counted as one time. Therefore, in order to more accurately count the number of incident photons, it is preferable to reduce the area occupied by each photodiode. In addition, in the case of high illumination, the dynamic range of each SPAD pixel 20 can be expanded by reducing the area occupied by each photodiode.

[0266] In this case, in the sixth embodiment, as Fig.33 As shown, the SPAD pixels 20R, 20G and 20B (hereinafter, the reference symbol is 20 when the SPAD pixels 20R, 20G and 20B are not distinguished) are respectively divided into a plurality of (in this example, four groups of 2×2 pixels) SPAD pixels 620R, 620G or 620B (hereinafter, the reference symbol is 620 when the SPAD pixels 620R, 620G and 620B are not distinguished). In other words, the plurality of SPAD pixels 620, 620G or 620B share one color filter 115R, 115G or 115B.

[0267] By dividing one SPAD pixel 20 into a plurality of SPAD pixels 620 in this way, the area of ​​each SPAD pixel 620 can be reduced, so the number of incident photons can be more accurately counted. In addition, since the area occupied by each photodiode is reduced, the dynamic range of each SPAD pixel 20 can be expanded.

[0268] Note that Fig.34 As shown, it is not necessary to provide the element separation unit 110 between the SPAD pixels 620 obtained by dividing one SPAD pixel 20. In this case, instead of the element separation unit 110, the P-type semiconductor region 104 may be arranged between the SPAD pixels 620. As a result, since the pixel pitch can be reduced compared to the case where the element separation unit 110 is provided, the size of the image sensor 10 can be further reduced.

[0269] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0270] 7. Seventh embodiment

[0271] Next, a solid-state imaging device and electronic equipment according to a seventh embodiment will be described in detail with reference to the drawings.

[0272] In the above-described sixth embodiment, the case where the P-type semiconductor region 104 is arranged between the plurality of SPAD pixels 620 into which one SPAD pixel 20 is divided has been shown, but the structure is not limited thereto.

[0273] For example, Fig.35 As shown, a trench may be provided between adjacent SPAD pixels 620 , and the inside of the trench may be filled with an insulating film 710 .

[0274] According to this structure, since optical crosstalk between adjacent SPAD pixels 620 can be suppressed, the number of incident photons can be counted more accurately.

[0275] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0276] 8. Eighth Embodiment

[0277] Next, a solid-state image pickup device and electronic equipment according to an eighth embodiment will be described in detail with reference to the drawings.

[0278] like Fig.36 As shown, for example, the element separation units 110 and 510 in the above-mentioned embodiments and their variations may penetrate through and cross the color filter 115 instead of staying inside the semiconductor substrate 101 .

[0279] By adopting a structure in which the element separation unit 110 penetrates the color filter 115 and protrudes above the color filter 115 , crosstalk between adjacent SPAD pixels 20 can be reduced.

[0280] Since other configurations, operations, and effects may be the same as those of the above-described embodiment or its modified example, detailed descriptions thereof will be omitted here.

[0281] 9. Ninth Embodiment

[0282] Next, a solid-state image pickup device and electronic equipment according to a ninth embodiment will be described in detail with reference to the drawings.

[0283] In the above-described embodiment and its modified example, for example, the anode contact 108 is provided at a step portion between the first trench T1 and the second trench T2. In the ninth embodiment, a configuration for increasing the contact area between the anode contact and the anode electrode in such a structure will be described.

[0284] 9.1 Example of a cross-sectional structure of a SPAD pixel

[0285] Fig.37: is a vertical cross-sectional view showing an example of a cross-sectional structure of a surface perpendicular to the light incident surface of a SPAD pixel according to the ninth embodiment. Fig.38 It shows Fig.37 Horizontal cross-sectional view of an example of a cross-sectional structure in plane AA.

[0286] Note that Fig.37 and Fig.38 In the figure, for the convenience of the following description, the boundary between the photoelectric conversion region 102 and the P-type semiconductor region 104 is slightly different from that in the above-mentioned figures. For example, the upper surface of the photoelectric conversion region 102, that is, the surface thereof facing the front surface (lower surface in the figure) side of the semiconductor substrate 101, is depicted at the same height as the bottom of the first trench. In addition, the side surface of the P-type semiconductor region 104 is pulled inward more than the inner end of the anode contact 908.

[0287] like Fig.37 As shown, the lower end portion of the anode electrode 922 included in the SPAD pixel 920 according to the ninth embodiment is not horizontal, but is inclined relative to the front surface of the semiconductor substrate 101. More specifically, the lower end portion of the anode electrode 922 is inclined from the end portion in the width direction of the anode electrode 922 toward the central portion thereof connected to the light shielding film 111 in the second groove in the depth direction of the semiconductor substrate 101, that is, inclined toward the second groove side. Therefore, the distance from the central portion in the width direction of the anode electrode 922 to the front surface of the semiconductor substrate 101 is longer than the distance from the end portion in the width direction of the anode electrode 922 to the front surface of the semiconductor substrate 101.

[0288] In addition, the anode contact 908 provided at the step portion between the first trench and the second trench contacts the inclined lower end portion of the anode electrode 922. That is, the anode contact 908 and the anode electrode 922 have an inclined contact surface. As a result, for example, the contact area between the anode contact 908 and the anode electrode 922 is larger than the case where the contact area between the anode contact 108 and the anode electrode 122 is horizontal to the front surface of the semiconductor substrate 101 as in the SPAD pixel 20 in the first embodiment.

[0289] In order to obtain such a structure, for example, the following manufacturing method can be adopted.

[0290] Fig.39 1 is a process cross-sectional view showing a method for manufacturing a solid-state imaging device according to a ninth embodiment. Fig.39 As shown, in the ninth embodiment, in the first embodiment, reference Fig.17 In the manufacturing stage similar to the cross-sectional structure described above, the bottom of the trench T5 is inclined with respect to the connecting portion T5s of the second trench T2.

[0291] More specifically, Fig.39The cross-sectional structure shown shows a case where, after acceptors are ion-implanted at a high concentration from the upper side of the insulating film 109 to the bottom of the trench T5, the entire surface of the insulating film 109 is etched back to remove the insulating film 109 at the bottom of the trench T5. At this time, by performing a longer etch back on the insulating film 109 than in the case of the first embodiment, for example, the connection portion with the second trench T2 protruding at an angle close to a right angle can be tilted, a part of the bottom of the trench T5 can be tilted, and the anode contact 908 can be exposed.

[0292] Thereafter, by filling the trench T5 with a conductive material, the anode electrode 922 in contact with the anode contact 908 on the inclined surface can be formed in the first trench T1 whose side surface is covered by the insulating film 109 .

[0293] 9.2 Effect

[0294] As described above, in this embodiment, the contact surface between anode contact 908 and anode electrode 922 is inclined relative to the front surface of semiconductor substrate 101. As a result, according to this embodiment, the contact area between anode contact 908 and anode electrode 922 can be increased and the contact resistance can be reduced.

[0295] When the photodiode is illuminated with light, a large current flows into the anode contact and the anode electrode. At this time, if the contact resistance at the anode contact is high, a voltage drop will occur.

[0296] In this embodiment, such a voltage drop can be suppressed and PDE can be improved. In addition, since it is not necessary to increase the voltage value to compensate for the dropped voltage, the power consumption of the solid-state imaging device can be reduced. As the photodiode is scaled down, it is expected that the effect of reducing the contact resistance will be further enhanced.

[0297] 9.3 Variations

[0298] Next, several specific modifications of the SPAD pixel 920 according to the ninth embodiment will be described.

[0299] In the SPAD pixel according to the modification, the first and second trenches extend to surround the element region while following a meandering trajectory. That is, in the present example where the photodiodes 21 are arranged in a lattice pattern, the length of each side of the first and second trenches is longer than the pitch of the photodiodes 21 .

[0300] As described above, since the first trench and the second trench surrounding the element region have redundancy in the extending direction, the contact area between the anode contact and the anode electrode can be increased.

[0301] 9.3.1 First Modification

[0302] Fig.40: is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a first modification of the ninth embodiment. Note that Fig.40 Shown with Fig.38 The surface corresponding to the surface in .

[0303] like Fig.40 As shown, in the ninth embodiment, reference Fig.38 In the structure similar to the cross-sectional structure described in the embodiment, the SPAD pixel 920a according to the first modification includes a first trench T1a formed in a zigzag shape in the extending direction of each side. A second trench arranged along the bottom of the first trench T1a is also formed in a zigzag shape in the extending direction of each side.

[0304] The anode electrode 922a provided in the first trench T1a is formed in a zigzag shape along the extending direction of each side of the first trench T1a. The light shielding film provided in the second trench is also formed in a zigzag shape in the extending direction of each side.

[0305] The anode contact 908a is formed in a zigzag shape along the extending direction of each side of the anode electrode 922a and contacts the anode electrode 922a. As a result, for example, as in the SPAD pixel 920 in the ninth embodiment, the extending length of each side of the first trench T1a is longer than the case where each side of the first trench is a straight line, and the contact area between the anode contact 908a and the anode electrode 922a can be increased.

[0306] 9.3.2 Second Modification

[0307] Fig.41 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a second modification of the ninth embodiment. Note that Fig.41 Shown with Fig.38 The surface corresponding to the surface in .

[0308] like Fig.41 As shown, in the ninth embodiment, reference Fig.38 In a structure similar to the cross-sectional structure described in , etc., the SPAD pixel 920b according to the second modification includes a first trench T1b formed in a crank shape in the extending direction of each side. A second trench provided along the bottom of the first trench T1b is also formed in a crank shape in the extending direction of each side.

[0309] The anode electrode 922b provided in the first trench T1b is formed in a crank shape along the extending direction of each side of the first trench T1b. The light shielding film provided in the second trench is also formed in a crank shape in the extending direction of each side.

[0310] The anode contact 908b is formed in a crank shape along the extension direction of each side of the anode electrode 922b and contacts the anode electrode 922b. As a result, for example, as in the SPAD pixel 920 in the ninth embodiment, the extension length of each side of the first trench T1b is longer than when each side of the first trench is a straight line, and the contact area between the anode contact 908b and the anode electrode 922b can be increased.

[0311] 9.3.3 Third variant

[0312] Fig.42 : is a horizontal cross-sectional view showing an example of a cross-sectional structure of a surface parallel to the light incident surface of a SPAD pixel according to a third modification of the ninth embodiment. Note that Fig.42 Shown with Fig.38 The surface corresponding to the surface in .

[0313] like Fig.42 As shown, similar to the first modification, in the ninth embodiment, reference Fig.38 In the structure similar to the cross-sectional structure described in the examples, the SPAD pixel 920c according to the third modification includes a first trench T1a, an anode electrode 922a and an anode contact 908a formed in a zigzag shape in the extending direction of each side. Similar to the first modification, the second trench and the light shielding film are also formed in a zigzag shape in the extending direction of each side.

[0314] The P-type semiconductor region 904c is formed in a zigzag shape along the extending direction of each side of the anode contact 908a, and is in contact with the anode contact 908a. As a result, for example, as in the SPAD pixel 920a in the first modification, the effective area of ​​the photoelectric conversion region 102 as a light sensitive area can be further expanded compared to the case where each side of the P-type semiconductor region is a straight line.

[0315] As described above, in the first to third modified examples, at least the anode contact and the anode electrode are formed in a zigzag or crank shape in the extending direction of each side. However, the anode contact and the anode electrode may also be formed in other shapes, such as a zigzag shape and a corrugated shape, as long as the anode contact and the anode electrode can be extended in length to increase their contact area.

[0316] Furthermore, in the above description, although the configurations in the first to third modified examples are applicable to the configuration in the ninth embodiment, that is, the configuration in which the anode contact 908 and the anode electrode 922 are in contact with each other at an inclined surface, the present invention is not limited thereto. The configurations in the first to third modified examples can also be applied to a configuration in which the contact surface between the anode contact 108 and the anode electrode 122 is horizontal, such as the configuration in the first embodiment.

[0317] In addition, for example, in the configuration of the first variant of the first embodiment, the insulating film 112 is not formed in the second groove, and the anode contact 108 is also in contact with the light shielding film 111 made of, for example, a conductive material. In the case where the configurations in the first to third variants are applied to such a configuration, the contact area between the anode contact and the light shielding film is added to the contact area between the anode contact and the anode electrode, and the contact resistance can be further reduced. At this time, in the case where the contact surface between the anode contact and the anode electrode is horizontal, the contact area between the anode contact and the anode electrode is small, while the contact area between the anode contact and the light shielding film is large. Therefore, it is possible to appropriately select a configuration in which the contact surface between the anode contact and the anode electrode is horizontal or a configuration in which the contact surface is inclined, so that the contact area between the anode contact and the anode electrode and the contact area between the anode contact and the light shielding film become larger.

[0318] 10. Application examples of electronic equipment

[0319] The above-described solid-state imaging element can be applied to various electronic devices, for example, imaging devices such as digital cameras and digital video cameras; mobile phones having an imaging function; and other devices having an imaging function.

[0320] Fig.43 : is a block diagram showing a configuration example of an imaging device as an electronic device to which the present technology is applied.

[0321] Fig.43 The illustrated imaging device 8201 includes an optical system 8202, a shutter device 8203, a solid-state imaging element 8204, a driving circuit 8205, a signal processing circuit 8206, a monitor 8207, and a memory 8208, and is capable of capturing still images and moving images.

[0322] The optical system 8202 includes one or more lenses, and guides light (incident light) from a subject to the solid-state imaging element 8204 to form an image on a light receiving surface of the solid-state imaging element 8204 .

[0323] The shutter device 8203 is arranged between the optical system 8202 and the solid-state imaging element 8204 , and controls a light irradiation period and a light shielding period of the solid-state imaging element 8204 according to control of the drive circuit 1005 .

[0324] The solid-state imaging element 8204 is composed of a package including the above-mentioned solid-state imaging element. The solid-state imaging element 8204 stores signal charges corresponding to light passing through the optical system 8202 and the shutter device 8203 for a certain period of time, thereby forming an image on the light receiving surface. The signal charges stored in the solid-state imaging element 8204 are transmitted according to the drive signal (timing signal) provided from the drive circuit 8205.

[0325] The driving circuit 8205 outputs a driving signal for controlling the transfer operation of the solid-state imaging element 8204 and the shutter operation of the shutter device 8203 to drive the solid-state imaging element 8204 and the shutter device 8203 .

[0326] The signal processing circuit 8206 performs various signal processing on the signal charge output from the solid-state imaging element 8204. The image (image data) obtained by the signal processing performed by the signal processing circuit 8206 is supplied to the monitor 8207 for display or supplied to the memory 8208 for storage (recording).

[0327] In the image pickup device 8201 configured in this manner, by using the solid-state image pickup element 1 instead of the above-described solid-state image pickup element 8204 , it is possible to capture an image with low noise in all pixels.

[0328] 11. Application examples for mobile objects

[0329] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be applied to a device installed on any type of mobile body, such as: an automobile, an electric car, a hybrid car, a motorcycle, a bicycle, a personal mobile device, an airplane, a drone, a ship, a robot, a construction machine, and an agricultural machine (tractor).

[0330] Fig.44 7000 is a block diagram showing a schematic configuration example of a vehicle control system 7000 as an example of a mobile body control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected to each other via a communication network 7010. Fig.44 In the example shown, the vehicle control system 7000 includes: a powertrain control unit 7100, a body device control unit 7200, a battery control unit 7300, an external information detection unit 7400, an internal information detection unit 7500, and an integrated control unit 7600. The communication network 7010 may be an in-vehicle communication network conforming to any standard, such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), and FlexRay (registered trademark).

[0331] Each control unit includes: a microcomputer that performs calculations based on various programs; a storage unit that stores programs executed by the microcomputer or parameters for various calculation operations; and a drive circuit that drives various controlled devices. Each drive unit includes a network I / F that communicates with other control units through the communication network 7010 and a communication I / F that communicates with devices or sensors inside and outside the vehicle through wired or wireless means. As a functional component of the integrated control unit 7600, Fig.44 There are shown a microcomputer 7610, a general communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, a vehicle internal device I / F 7660, an audio and video output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Other control units also include a microcomputer, a communication I / F, a storage unit, etc.

[0332] The transmission control unit 7100 controls the operation of the transmission device of the vehicle based on various programs. For example, the transmission control unit 7100 serves as a control device for the following devices: a driving force generator for generating driving force of the vehicle, such as an internal combustion engine and a driving motor; a driving force transmission mechanism for transmitting driving force to wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating braking force of the vehicle, etc. The transmission control unit 7100 may have the function of a control device, such as an anti-lock braking system (ABS) and an electronic stability control (ESC).

[0333] The vehicle state detection unit 7110 is connected to the powertrain control unit 7100. The vehicle state detection unit 7110 includes, for example, a gyro sensor for detecting the angular velocity of the shaft rotation of the vehicle body, an acceleration sensor for detecting the acceleration of the vehicle, or at least one of sensors for detecting the accelerator pedal operation amount, the brake pedal operation amount, the steering wheel steering angle, the engine speed, and the wheel speed, etc. The powertrain control unit 7100 performs calculation processing using the signal input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0334] The body device control unit 7200 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body device control unit 7200 is used as a control device for the following devices: a keyless entry system; a smart key system; a power window device; or various lights such as headlights, taillights, brake lights, turn signals, and fog lights. In this case, the body device control unit 7200 can receive radio waves or signals of various switches sent from a portable device that replaces the key. The body device control unit 7200 receives input of these radio waves or signals and controls the door lock device, power window device, and lights of the vehicle.

[0335] The battery control unit 7300 controls the secondary battery 7310 as a power source for driving the motor according to various programs. For example, the battery control unit 7300 receives information such as battery temperature, battery output voltage, and remaining amount of the battery from a battery device including the secondary battery 7310. The battery control unit 7300 performs operation processing using these signals and controls the temperature of the secondary battery 7310 or controls a cooling device provided in the battery device.

[0336] The vehicle exterior information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of the camera unit 7410 and the vehicle exterior information detection unit 7420 is connected to the vehicle exterior information detection unit 7400. The camera unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The vehicle exterior information detection unit 7420 includes, for example, an environmental sensor for detecting the current weather and at least one of a surrounding information detection sensor for detecting vehicles, obstacles, pedestrians, etc. other than the vehicle equipped with the vehicle control system 7000.

[0337] The environmental sensor may be, for example, at least one of a raindrop sensor for detecting rainy weather, a fog sensor for detecting fog, a daylight sensor for detecting the amount of daylight, and a snow sensor for detecting snowfall. The surrounding information detection sensor may include at least one of an ultrasonic sensor, a radar device, and a light detection and ranging (LIDAR) device or a laser imaging detection and ranging (LIDAR) device. The camera unit 7410 and the vehicle exterior information detection unit 7420 may be provided as separate sensors and devices, or may be provided as a device in which a plurality of sensors and devices are integrated.

[0338] here, Fig.45 An example of the installation position of the camera unit 7410 and the vehicle exterior information detection unit 7420 is shown. For example, the camera units 7910, 7912, 7914, 7916, and 7918 are arranged at least one of the front nose, rearview mirror, rear bumper, rear door, and upper portion of the windshield in the vehicle 7900. The camera unit 7910 arranged at the front nose and the camera unit 7918 arranged at the upper portion of the windshield in the vehicle mainly acquire images in front of the vehicle 7900. The camera units 7912 and 7914 arranged at the rearview mirror mainly acquire images on the side of the vehicle 7900. The camera unit 7916 arranged at the rear bumper or rear door mainly acquires images behind the vehicle 7900. The camera unit 7918 arranged at the upper portion of the windshield in the vehicle is mainly used to detect the preceding vehicle, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0339] Notice, Fig.45An example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916 is shown. The imaging range a represents the imaging range of the imaging unit 7910 provided at the front nose, the imaging ranges b and c represent the imaging ranges of the imaging units 7912 and 7914 provided at the rearview mirror, respectively, and the imaging range d represents the imaging range of the imaging unit 7916 provided at the rear bumper or the rear door. For example, by superimposing the image data acquired by the imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of the vehicle 7900 observed from above can be obtained.

[0340] For example, the vehicle exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided at the front, rear, sides, and corners of the vehicle 7900 and the upper portion of the windshield inside the vehicle may be ultrasonic sensors or radar devices. For example, the vehicle exterior information detection units 7920, 7926, and 7930 provided at the front nose, rear bumper, rear door, and the upper portion of the windshield inside the vehicle 7900 may be LIDAR devices. These vehicle exterior information detection units 7920 to 7930 are mainly used to detect the preceding vehicle, pedestrians, or obstacles, etc.

[0341] Return to Fig.44 , continue the description. The vehicle exterior information detection unit 7400 enables the camera unit 7410 to capture an image of the outside of the vehicle and receives the captured image data. The vehicle exterior information detection unit 7400 also receives detection information from the connected vehicle exterior information detection unit 7420. In the case where the vehicle exterior information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the vehicle exterior information detection unit 7400 enables the vehicle exterior information detection unit 7420 to emit ultrasonic waves or electromagnetic waves, etc., and receives information of the received reflected waves. The vehicle exterior information detection unit 7400 can perform object detection processing or distance detection processing on pedestrians, vehicles, obstacles, signs, or text on the road surface based on the received information. The vehicle exterior information detection unit 7400 can perform environment recognition processing for identifying rainfall, fog, or road surface conditions, etc. based on the received information. The vehicle exterior information detection unit 7400 can calculate the distance to objects outside the vehicle based on the received information.

[0342] In addition, the vehicle exterior information detection unit 7400 can perform image recognition processing or distance detection processing on pedestrians, vehicles, obstacles, signs, or letters on the road surface based on the received image data. The vehicle exterior information detection unit 7400 can perform processing such as distortion correction and position adjustment on the received image data, and synthesize the image data captured by other camera units 7410 to generate a bird's-eye view image or a panoramic view. The vehicle exterior information detection unit 7400 can use the image data captured by other camera units 7410 to perform viewpoint switching processing.

[0343] The in-vehicle information detection unit 7500 detects information inside the vehicle. For example, a driver state detection unit 7510 that detects the driver's state is connected to the in-vehicle information detection unit 7500. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's vital information, or a microphone that collects sounds inside the vehicle, etc. For example, the biosensor is set on the seat surface or the steering wheel, and detects the vital information of the occupant sitting on the seat or the driver holding the steering wheel. The in-vehicle information detection unit 7500 can calculate the driver's fatigue or concentration based on the detection information input from the driver state detection unit 7510, and determine whether the driver has fallen asleep. The in-vehicle information detection unit 7500 can perform processing such as noise reduction processing on the collected audio signal.

[0344] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 based on various programs. The input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is implemented by a device that can be input by an occupant, such as a touch panel, a button, a microphone, a switch, and a joystick. The data obtained by recognizing the voice input by the microphone can be input into the integrated control unit 7600. For example, the input unit 7800 can be a remote control device using infrared or other radio waves, or an external connection device such as a mobile phone and a personal digital assistant (PDA) that supports the operation of the vehicle control system 7000. For example, the input unit 7800 can be a camera, in which case the occupant can input information through gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant can be input. In addition, the input unit 7800 may include, for example, an input control circuit that generates an input signal according to the information input by the occupant, etc. using the above-mentioned input unit 7800, and outputs the input signal to the integrated control unit 7600. The input unit 7800 is operated by an occupant or the like to input various data into the vehicle control system 7000 and to instruct the vehicle control system 7000 to perform processing operations.

[0345] The storage unit 7690 may include a read-only memory (ROM) storing various programs executed by the microcomputer and a random access memory (RAM) storing various parameters, calculation results, or sensor values, etc. In addition, the storage unit 7690 may be implemented by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0346] The general communication I / F 7620 is a general communication I / F that mediates communication with various devices present in the external environment 7750. The general communication I / F 7620 can implement cellular communication protocols such as Global System for Mobile Communications (GSM (registered trademark), WiMAX (registered trademark), Long Term Evolution (LTE (registered trademark)) and LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also known as Wi-Fi (registered trademark)) and Bluetooth (registered trademark). For example, the general communication I / F 7620 can be connected to a device (e.g., an application server or a control server) present on an external network (e.g., the Internet, a cloud network, or a network specific to a business operator) through a base station or an access point. In addition, for example, the general communication I / F 7620 can be connected to a terminal (e.g., a terminal of a driver, a pedestrian, or a store, or a machine type communication (MTC) terminal) present near the vehicle using a point-to-point (P2P) technology.

[0347] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol for a vehicle. The dedicated communication I / F 7630 may implement a standard protocol such as Wireless Access in Vehicular Environments (WAVE) which is a combination of the low-layer IEEE 802.11p and the high-layer IEEE 1609, Dedicated Short Range Communication (DSRC), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more types of communication among communication between vehicles (Vehicle to Vehicle), communication between roads and vehicles (Vehicle to Infrastructure), communication between vehicles and houses (Vehicle to Home), and communication between pedestrians and vehicles (Vehicle to Pedestrian).

[0348] For example, the positioning unit 7640 receives a global navigation satellite system (GNSS) signal from a GNSS satellite (e.g., a global positioning system (GPS) signal from a GPS satellite), performs positioning, and generates position information including the latitude, longitude, and altitude of the vehicle. Note that the positioning unit 7640 may specify the current position by exchanging signals with a wireless access point, or may acquire position information from a terminal having a positioning function such as a mobile phone, a PHS, and a smart phone.

[0349] The beacon receiving unit 7650 receives electric waves or electromagnetic waves transmitted from a radio station installed on the road, etc., and acquires information such as the current position, traffic congestion, road closures, and required time. Note that the function of the beacon receiving unit 7650 may be included in the above-mentioned dedicated communication I / F 7630.

[0350] The vehicle interior device I / F 7660 is a communication interface for adjusting the connection between the microcomputer 7610 and various vehicle interior devices 7760 present in the vehicle. The vehicle interior device I / F 7660 can establish a wireless connection using wireless communication protocols such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), and wireless USB (WUSB). In addition, the vehicle interior device I / F 7660 can establish wired communication through a universal serial bus (USB), a high-definition multimedia interface (HDMI (registered trademark)), or a mobile high-definition link (MHL) via a connection terminal not shown (and a cable if necessary). For example, the vehicle interior device 7760 may include at least one of a mobile device or wearable device owned by an occupant, and an information device carried or attached in the vehicle. The vehicle interior device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The vehicle interior device I / F 7660 exchanges control signals or data signals with these vehicle interior devices 7760.

[0351] The in-vehicle network I / F 7680 is an interface that regulates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits / receives signals and the like according to a predetermined protocol supported by the communication network 7010.

[0352] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired through at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the vehicle internal device I / F 7660, and the vehicle network I / F 7680. For example, the microcomputer 7610 can calculate the control target value of the driving force generator, the steering mechanism, or the braking device based on the acquired information inside and outside the vehicle, and can output a control command to the powertrain control unit 7100. For example, the microcomputer 7610 can perform cooperative control for realizing the functions of an advanced driver assistance system (ADAS), including collision avoidance or collision mitigation of a vehicle, following driving based on a vehicle-to-vehicle distance, speed-maintaining driving, vehicle collision warning, and lane departure warning of a vehicle. In addition, the microcomputer 7610 can control the driving force generator, steering mechanism or braking device based on the information obtained inside and outside the vehicle, thereby performing cooperative control for realizing automatic driving that allows the vehicle to drive autonomously without relying on the driver's operation.

[0353] The microcomputer 7610 can generate three-dimensional distance information between the vehicle and an object (e.g., surrounding structures and people) based on information acquired through at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the vehicle internal device I / F 7660, and the vehicle network I / F 7680, and generate local map information including surrounding information of the current position of the vehicle. In addition, the microcomputer 7610 can predict dangers such as vehicle collision, pedestrians approaching, and entering a closed road based on the acquired information, and generate a warning signal. The warning signal can be, for example, a signal that generates a warning sound or lights a warning light.

[0354] The audio and video output unit 7670 transmits at least one of an audio output signal or a video output signal to an output device, which can visually or auditorily notify information to passengers in the vehicle or outside the vehicle. Fig.44 In the example of , as output devices, an audio speaker 7710, a display unit 7720, and a dashboard 7730 are illustrated. For example, the display unit 7720 may include at least one of an on-board display and a head-up display. The display unit 7720 may have an augmented reality (AR) display function. Instead of these devices, the output device may also be other devices, such as wearable devices such as headphones, glasses-type displays worn by passengers, projectors, and lights. In the case where the output device is a display device, the display device visually displays the results obtained by various processing performed by the microcomputer 7610 or information received from other control units in various forms such as text, images, tables, and graphics. In addition, in the case where the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or acoustic data into an analog signal, and outputs the audio signal in an audible manner.

[0355] Note that Fig.44 In the example shown, at least two control units connected via the communication network 7010 can be integrated into one control unit. Alternatively, each control unit can be composed of multiple control units. In addition, the vehicle control system 7000 may include other control units not shown. In addition, in the above description, another control unit may have some or all of the functions performed by any control unit. That is, as long as information is sent and received via the communication network 7010, any one control unit can perform predetermined calculation processing. Similarly, a sensor or device connected to one of the control units can be connected to another control unit, and multiple control units can send and receive detection information to each other via the communication network 7010.

[0356] Note that for reference Figure 1The computer program of each function of the electronic device 1 according to the present embodiment described can be installed on any control unit, etc. A computer-readable recording medium in which such a computer program is stored can also be provided. The recording medium is, for example, a disk, an optical disk, a magneto-optical disk, or a flash memory. In addition, the above-mentioned computer program can also be distributed, for example, via a network, without using a recording medium.

[0357] In the above vehicle control system 7000, reference Figure 1 The electronic device 1 according to the present embodiment described above can be applied to Fig.44 The integrated control unit 7600 of the application example shown. For example, the storage unit 40 and the processor 50 of the electronic device 1 correspond to the microcomputer 7610, the storage unit 7690, and the vehicle network I / F 7680 of the integrated control unit 7600. However, the present invention is not limited thereto, and the vehicle control system 7000 may correspond to Figure 1 Host 80 in.

[0358] In addition, reference Figure 1 At least part of the components of the electronic device 1 according to the present embodiment described may be used in a Fig.44 The integrated control unit 7600 shown in FIG. 7 is implemented in a module (eg, an integrated circuit module consisting of a bare chip). Alternatively, referring to Figure 1 The electronic device 1 according to the present embodiment can be composed of Fig.44 The vehicle control system 7000 shown is implemented by multiple control units.

[0359] 12. Application examples of endoscopic surgery systems

[0360] In addition, the technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0361] Fig.46 : 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.

[0362] Fig.46 The figure shows a state where a surgeon (doctor) 11131 performs surgery on a patient 11132 on a bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 for supporting the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are installed.

[0363] The endoscope 11100 includes: a barrel 11101, a region having a predetermined length from the front end of the barrel 11101 is inserted into the body cavity of a patient 11132; and a camera 11102 connected to the base end of the barrel 11101. In the illustrated example, the endoscope 11100 used as a so-called rigid scope having a rigid barrel 11101 is shown, but the endoscope 11100 can also be used as a so-called flexible scope having a flexible barrel.

[0364] An opening is provided at the front end of the lens barrel 11101, and an objective lens is installed in the opening. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the front end of the lens barrel through a light guide extending in the lens barrel 11101, and the light is irradiated onto an observation target in the body cavity of the patient 11132 via the objective lens. Note that the endoscope 11100 may be a forward-looking endoscope, an oblique-looking endoscope, or a side-looking endoscope.

[0365] An optical system and an imaging element are provided in the camera head 11102. The reflected light (observation light) from the observation target is focused on the imaging element through the optical system. The observation light is photoelectrically converted by the imaging element, and an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image is generated. The image signal is sent to the camera control unit (CCU: camera control unit) 11201 as raw data.

[0366] The CCU 11201 includes a central processing unit (CPU) and a graphics processing unit (GPU), etc., and the CCU 11201 integrally controls the operations of the endoscope 11100 and the display device 11202. In addition, the CCU 11201 receives an image signal from the camera 11102, and performs various image processing such as development processing (demosaic processing) on ​​the image signal for displaying an image based on the image signal.

[0367] Under the control of the CCU 11201 , the display device 11202 displays an image based on an image signal subjected to image processing by the CCU 11201 .

[0368] The light source device 11203 includes a light source such as a light emitting diode (LED), and provides the endoscope 11100 with irradiation light for photographing a surgical site or the like.

[0369] The input device 11204 is an input interface of the endoscopic surgery system 11000. The user can input various information and instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user inputs an instruction for changing the imaging conditions of the endoscope 11100 (type of irradiation light, magnification, focal length, etc.).

[0370] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterization, cutting of tissues, closure of blood vessels, etc. The inflation device 11206 delivers gas to the body cavity of the patient 11132 through the inflation tube 11111 to expand the body cavity, thereby ensuring the field of view of the endoscope 11100 and ensuring the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the operation. The printer 11208 is a device capable of printing various information related to the operation in various forms such as text, images, and charts.

[0371] Note that the light source device 11203 that provides the endoscope 11100 with irradiation light for photographing the surgical site can be composed of a white light source, which includes, for example, an LED, a laser light source, or a combination of an LED and a laser light source. In the case where the white light source includes a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision. Therefore, the light source device 11203 can adjust the white balance of the captured image. In addition, in this case, by irradiating the observed object with laser beams from each of the RGB laser light sources in a time-division manner, and controlling the drive of the imaging element of the camera 11102 in synchronization with the irradiation timing, images corresponding to the RGB laser beams can be captured in a time-division manner. According to this method, a color image can be obtained even if a color filter is not provided in the imaging element.

[0372] In addition, the drive of the light source device 11203 can be controlled so that the intensity of the output light is changed at a predetermined time interval. By controlling the drive of the imaging element of the camera 11102 in synchronization with the timing of the light intensity change and acquiring images in a time-division manner, and then synthesizing the images, a high dynamic range image without so-called underexposure and overexposure can be generated.

[0373] In addition, the light source device 11203 may be configured to provide light of a predetermined wavelength band corresponding to special light observation. In special light observation, for example, by utilizing the wavelength dependence of light absorption in human tissue to irradiate light of a narrower band than the band of irradiation light (i.e., white light) used in ordinary observation, so-called narrow-band light observation (narrow-band imaging) is performed, wherein predetermined tissues such as blood vessels in the surface layer of the mucosa are imaged with high contrast. Alternatively, in special light observation, fluorescence observation in which an image is obtained by irradiating fluorescence generated by excitation light may be performed. In fluorescence observation, fluorescence from human tissue can be observed by irradiating the human tissue with excitation light (autofluorescence observation), or a fluorescent image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into the human tissue and irradiating the human tissue with excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 may be configured to provide narrow-band light and / or excitation light corresponding to such special light observation.

[0374] Fig.47 It is shown Fig.46 A block diagram of an example of the functional configuration of the camera 11102 and the CCU 11201 shown.

[0375] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are communicably connected to each other via a transmission cable 11400.

[0376] The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. Observation light acquired from the front end of the lens barrel 11101 is guided to the camera 11102 and enters the lens unit 11401. The lens unit 11401 is formed by combining a plurality of lenses including a zoom lens and a focus lens.

[0377] The imaging unit 11402 is composed of imaging elements. The number of imaging elements constituting the imaging unit 11402 may be one (so-called single-board type) or multiple (so-called multi-board type). For example, in the case where the imaging unit 11402 is a multi-board type, image signals corresponding to R, G, and B, respectively, may be generated by each imaging element, and these image signals may be synthesized to obtain a color image. Alternatively, the imaging unit 11402 may include a pair of imaging elements for respectively acquiring a right-eye image signal and a left-eye image signal corresponding to a three-dimensional (3D) display. Through the 3D display, the surgeon 11131 is able to more accurately grasp the depth of living tissue in the surgical site. Note that in the case where the imaging unit 11402 is a multi-board type, a plurality of lens units 11401 may be provided corresponding to each imaging element.

[0378] In addition, the camera unit 11402 does not have to be arranged on the camera head 11102. For example, the camera unit 11402 can be arranged in the lens barrel 11101 close to the objective lens.

[0379] The drive unit 11403 includes an actuator and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera control unit 11405. As a result, the magnification and focus of the image captured by the camera unit 11402 can be appropriately adjusted.

[0380] The communication unit 11404 includes a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the camera unit 11402 to the CCU 11201 through the transmission cable 11400 as raw data.

[0381] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and provides the control signal to the camera control unit 11405. The control signal includes information related to imaging conditions, for example, information specifying a frame rate of an image to be captured, information specifying an exposure value during imaging, and / or information specifying a magnification and a focus of an image to be captured.

[0382] Note that imaging conditions such as frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, the endoscope 11100 has a so-called auto exposure (AE) function, an auto focus (AF) function, and an auto white balance (AWB) function.

[0383] The camera control unit 11405 controls the driving of the camera 11102 based on the control signal from the CCU 11201 received through the communication unit 11404 .

[0384] The communication unit 11411 includes a communication device for transmitting and receiving various information to and from the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 through the transmission cable 11400.

[0385] In addition, the communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal can be transmitted through electrical communication, optical communication, or the like.

[0386] The image processing unit 11412 performs various image processing on the image signal used as raw data sent from the camera 11102 .

[0387] The control unit 11413 performs various controls related to imaging the surgical site, etc. through the endoscope 11100 and displaying 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 .

[0388] In addition, based on the image signal that has been image-processed by the image processing unit 11412, the control unit 11413 causes the display device 11202 to display the captured image of the surgical site, etc. At this time, the control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, the control unit 11413 can detect surgical tools such as forceps, specific living parts, bleeding, and mist when using the energy treatment tool 11112, etc. by detecting the shape and color of the edges of the objects included in the captured image. When the control unit 11413 displays the captured image on the display device 11202, the control unit 11413 can use the recognition result to superimpose and display various surgical auxiliary information on the image of the surgical site. By superimposing and displaying the surgical auxiliary information and presenting the surgical auxiliary information to the surgeon 11131, the burden of the surgeon 11131 can be reduced, and it can be ensured that the surgeon 11131 can perform the operation safely.

[0389] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable compatible with both electrical communication and optical communication.

[0390] Here, in the example shown, although communication is performed by wired communication using the transmission cable 11400, communication between the camera 11102 and the CCU 11201 may be performed wirelessly.

[0391] An example of an endoscopic surgical system to which the technology of the present disclosure can be applied has been described above. The technology of the present disclosure can be applied to, for example, the imaging unit 11402 of the endoscope 11100 and the camera 11102 in the above-mentioned structure. By applying the technology of the present disclosure to the imaging unit 11402, etc., it is possible to acquire high-brightness image data while suppressing a decrease in resolution.

[0392] Note that although an endoscopic surgery system is described here as an example, the technology according to the present disclosure can also be applied to other systems such as a microsurgery system.

[0393] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present disclosure. In addition, components in different embodiments and modified examples can be appropriately combined.

[0394] Furthermore, the effects of the various embodiments described in this specification are merely illustrative and not restrictive, and other effects may be provided.

[0395] 13. Appendix

[0396] Note that the present technology can also adopt the following configurations. (1)

[0398] A solid-state imaging device comprising:

[0399] a semiconductor substrate including a first trench disposed on a first surface and a second trench disposed along a bottom of the first trench; and

[0400] A photoelectric conversion element is provided on a semiconductor substrate.

[0401] Wherein, the photoelectric conversion element comprises:

[0402] a photoelectric conversion region which is provided in an element region partitioned by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges;

[0403] a first semiconductor region surrounding the photoelectric conversion region in the element region;

[0404] a first contact in contact with the first semiconductor region at the bottom of the first trench;

[0405] a first electrode in contact with the first contact in the first trench;

[0406] a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region;

[0407] a third semiconductor region serving as a region in contact with the second semiconductor region in the element region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type;

[0408] a second contact provided on the first surface to contact the third semiconductor region; and

[0409] a second electrode in contact with the second contact, and

[0410] A second surface at which the first contact and the first electrode contact each other is inclined with respect to the first surface. (2)

[0412] The solid-state imaging device according to (1), wherein

[0413] The second surface is inclined toward the second groove side from the end portion of the first electrode in the width direction toward the center portion thereof. (3)

[0415] The solid-state imaging device according to (1) or (2), wherein:

[0416] The first trench and the second trench extend in a serpentine path to surround the device region. (4)

[0418] The solid-state imaging device according to any one of (1) to (3), wherein:

[0419] The distance from the first contact to the first surface is longer than the distance from the third semiconductor region to the first surface. (5)

[0421] The solid-state imaging device according to any one of (1) to (4), wherein:

[0422] The first contact contacts the first semiconductor region to surround an outer periphery of the first semiconductor region. (6)

[0424] The solid-state imaging device according to any one of (1) to (5), further comprising:

[0425] A light shielding film is provided inside the second trench. (7)

[0427] The solid-state imaging device according to (6), wherein

[0428] The light shielding film is made of the same material as that of the first electrode. (8)

[0430] The solid-state imaging device according to (6) or (7), further comprising:

[0431] An insulating film is provided between the light shielding film and the first semiconductor region. (9)

[0433] A solid-state imaging device comprising:

[0434] a semiconductor substrate including a first trench disposed on a first surface and a second trench disposed along a bottom of the first trench; and

[0435] at least one photoelectric conversion element disposed on a semiconductor substrate,

[0436] Wherein, the photoelectric conversion element comprises:

[0437] a photoelectric conversion region which is provided in an element region partitioned by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges;

[0438] a first semiconductor region surrounding the photoelectric conversion region in the element region;

[0439] a first contact in contact with the first semiconductor region at the bottom of the first trench;

[0440] a first electrode in contact with the first contact in the first trench;

[0441] a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region;

[0442] a third semiconductor region serving as a region in contact with the second semiconductor region in the element region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type;

[0443] a second contact provided on the first surface to contact the third semiconductor region; and

[0444] a second electrode in contact with the second contact, and

[0445] The first trench and the second trench extend in a serpentine path to surround the device region. (10)

[0447] The solid-state imaging device according to (9), wherein

[0448] The first groove and the second groove are respectively formed in at least any one of a zigzag shape, a crank shape, and a zigzag shape in the extending direction. (11)

[0450] The solid-state imaging device according to (9) or (10), wherein:

[0451] The first electrode extends along the first trench in a winding path so as to surround the device region. (12)

[0453] The solid-state imaging device according to (11), wherein

[0454] The first contact extends along the first electrode in a meandering path so as to surround the outer periphery of the first semiconductor region and is in contact with the first electrode. (13)

[0456] The solid-state imaging device according to (12), wherein:

[0457] The first semiconductor region extends along the first contact so as to surround the photoelectric conversion region in a meandering path, and is in contact with the first contact. (14)

[0459] The solid-state imaging device according to any one of (9) to (13), wherein:

[0460] A plurality of photoelectric conversion elements are provided,

[0461] A plurality of photoelectric conversion elements are arranged in a grid pattern,

[0462] The pitch of each of the plurality of photoelectric conversion elements in the first direction is equal to the pitch thereof in a second direction perpendicular to the first direction, and

[0463] The length of each side of the first trench and the second trench surrounding the device region is longer than the pitch between the plurality of photoelectric conversion devices. (15)

[0465] The solid-state imaging device according to any one of (9) to (14), further comprising:

[0466] A light shielding film is provided inside the second trench. (16)

[0468] The solid-state imaging device according to (15), wherein

[0469] The light shielding film is made of the same material as that of the first electrode. (17)

[0471] The solid-state imaging device according to (15) or (16), wherein:

[0472] The light shielding film is in contact with the first semiconductor region. (18)

[0474] The solid-state imaging device according to (15) or (16), further comprising:

[0475] An insulating film is provided between the light shielding film and the first semiconductor region. (19)

[0477] An electronic device comprising:

[0478] Solid-state camera device;

[0479] an optical system that forms an image on a light receiving surface of a solid-state imaging device by incident light; and

[0480] A processor that controls a solid-state imaging device,

[0481] The solid-state imaging device includes:

[0482] a semiconductor substrate including a first trench disposed on a first surface and a second trench disposed along a bottom of the first trench; and

[0483] A photoelectric conversion element is provided on a semiconductor substrate,

[0484] The photoelectric conversion element comprises:

[0485] a photoelectric conversion region which is provided in an element region partitioned by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges;

[0486] a first semiconductor region surrounding the photoelectric conversion region in the element region;

[0487] a first contact in contact with the first semiconductor region at the bottom of the first trench;

[0488] a first electrode in contact with the first contact in the first trench;

[0489] a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region;

[0490] a third semiconductor region serving as a region in contact with the second semiconductor region in the element region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type;

[0491] a second contact provided on the first surface to contact the third semiconductor region; and

[0492] a second electrode in contact with the second contact, and

[0493] A second surface at which the first contact and the first electrode contact each other is inclined with respect to the first surface. (20)

[0495] An electronic device comprising:

[0496] Solid-state camera device;

[0497] an optical system that forms an image on a light receiving surface of a solid-state imaging device by incident light; and

[0498] A processor that controls a solid-state imaging device,

[0499] The solid-state imaging device includes:

[0500] a semiconductor substrate including a first trench disposed on a first surface and a second trench disposed along a bottom of the first trench; and

[0501] A photoelectric conversion element is provided on a semiconductor substrate,

[0502] The photoelectric conversion element comprises:

[0503] a photoelectric conversion region which is provided in an element region partitioned by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges;

[0504] a first semiconductor region surrounding the photoelectric conversion region in the element region;

[0505] a first contact in contact with the first semiconductor region at the bottom of the first trench;

[0506] a first electrode in contact with the first contact in the first trench;

[0507] a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region;

[0508] a third semiconductor region serving as a region in contact with the second semiconductor region in the element region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type;

[0509] a second contact provided on the first surface to contact the third semiconductor region; and

[0510] a second electrode in contact with the second contact, and

[0511] The first trench and the second trench extend in a serpentine path to surround the device region.

[0512] Reference numerals list

[0513] 1 Electronic equipment

[0514] 10 Solid-state imaging device

[0515] 11 SPAD array unit

[0516] 12. Driving Circuit

[0517] 13 Output Circuit

[0518] 15 Timing Control Circuit

[0519] 20,20a,20b,20c,20d,220,20B,20G,20R,620B,620G,620R,920,920a,920b,920cSPAD pixels

[0520] 21 Photodiode

[0521] 22 Readout circuit

[0522] 23 Quenching resistor

[0523] 24 Select transistor

[0524] 25 Digital Converter

[0525] 251 Resistor

[0526] 26 Inverter

[0527] 27 Buffer

[0528] 30 Camera Lens

[0529] 40 storage units

[0530] 50 processors

[0531] 60 color filter array

[0532] 61 unit pattern

[0533] 71 Optical receiving chip

[0534] 72 Circuit Chip

[0535] 101,141 Semiconductor substrate

[0536] 102 Photoelectric conversion area

[0537] 103 N-type semiconductor region

[0538] 104,104a,904c P-type semiconductor region

[0539] 105,105A P+ type semiconductor region

[0540] 106,106A N+ type semiconductor region

[0541] 107 Cathode contact

[0542] 108,108A,408,508,908,908a,908b Anode contact

[0543] 109,109A,109B,109D Insulation film

[0544] 110,310,510 Component separation unit

[0545] 111,311,511 Light-shielding film

[0546] 112,312,512,710 Insulation film

[0547] 113 Pinning layer

[0548] 114 planarization film

[0549] 115,115R,115G,115B Color Filters

[0550] 116 On-chip lens

[0551] 120,130 Wiring layer

[0552] 121 cathode electrode

[0553] 122,922,922a,922b Anode electrode

[0554] 123,131 Interlayer insulation film

[0555] 124,132 Wiring

[0556] 125,135 connection pads

[0557] 142 Circuit Elements

[0558] 252,262 NMOS transistors

[0559] 261 PMOS transistor

[0560] A1, A2, A3 opening

[0561] LD pixel drive line

[0562] LS output signal line

[0563] M1,M2,M3,M4 Mask

[0564] T1,T1a,T1b First groove

[0565] T2 Second groove

[0566] T3,T4,T5,T11 groove

Claims

1. A solid-state imaging device, comprising: A semiconductor substrate comprising a first groove disposed on a first surface and a second groove disposed along a bottom of the first groove; and a photoelectric conversion element disposed on the semiconductor substrate, Wherein, the photoelectric conversion element comprises: a photoelectric conversion region which is provided in an element region divided by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges; a first semiconductor region surrounding the photoelectric conversion region in the element region; a first contact in contact with the first semiconductor region at a bottom of the first trench; a first electrode in contact with the first contact in the first trench; a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region; a third semiconductor region serving as a region in the element region in contact with the second semiconductor region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type; a second contact provided on the first surface to contact the third semiconductor region; and a second electrode in contact with the second contact, and A second surface at which the first contact and the first electrode contact each other is inclined with respect to the first surface.

2. The solid-state imaging device according to claim 1, wherein The second surface is inclined toward the second groove side from the end portion of the first electrode in the width direction toward the center portion thereof.

3. The solid-state imaging device according to claim 1 or 2, wherein: The first trench and the second trench extend in a serpentine path to surround the device region.

4. The solid-state imaging device according to claim 1 or 2, wherein: A distance from the first contact to the first surface is longer than a distance from the third semiconductor region to the first surface.

5. The solid-state imaging device according to claim 1 or 2, wherein: The first contact is in contact with the first semiconductor region to surround an outer periphery of the first semiconductor region.

6. The solid-state imaging device according to claim 1 or 2, further comprising: A light shielding film is disposed inside the second groove.

7. The solid-state imaging device according to claim 6, wherein: The light shielding film is made of the same material as that of the first electrode.

8. The solid-state imaging device according to claim 6, further comprising: An insulating film is provided between the light shielding film and the first semiconductor region.

9. A solid-state imaging device, comprising: A semiconductor substrate comprising a first groove disposed on a first surface and a second groove disposed along a bottom of the first groove; and A photoelectric conversion element is provided on the semiconductor substrate, Wherein, the photoelectric conversion element comprises: a photoelectric conversion region which is provided in an element region divided by the first trench and the second trench in the semiconductor substrate and performs photoelectric conversion on incident light to generate electric charges; a first semiconductor region surrounding the photoelectric conversion region in the element region; a first contact in contact with the first semiconductor region at a bottom of the first trench; a first electrode in contact with the first contact in the first trench; a second semiconductor region provided in a region in contact with the first semiconductor region in the element region and having a first conductivity type which is the same as the conductivity type of the first semiconductor region; a third semiconductor region serving as a region in the element region in contact with the second semiconductor region, provided between the second semiconductor region and the first surface, and having a second conductivity type opposite to the first conductivity type; a second contact provided on the first surface to contact the third semiconductor region; and a second electrode in contact with the second contact, and The first trench and the second trench extend in a serpentine path to surround the device region.

10. The solid-state imaging device according to claim 9, wherein: The first groove and the second groove are respectively formed in at least any one of a zigzag shape, a crank shape, and a zigzag shape in an extending direction.

11. The solid-state imaging device according to claim 9 or 10, wherein: The first electrode extends along the first trench in a winding path so as to surround the device region.

12. The solid-state imaging device according to claim 11, wherein The first contact extends along the first electrode in a serpentine path so as to surround the outer periphery of the first semiconductor region and is in contact with the first electrode.

13. The solid-state imaging device according to claim 12, wherein: The first semiconductor region extends along the first contact so as to surround the photoelectric conversion region in a meandering path, and is in contact with the first contact.

14. The solid-state imaging device according to claim 9 or 10, wherein: A plurality of the photoelectric conversion elements are provided, The plurality of photoelectric conversion elements are arranged in a lattice pattern, The pitch of each of the plurality of photoelectric conversion elements in the first direction is equal to the pitch of each of the plurality of photoelectric conversion elements in the second direction perpendicular to the first direction, and The length of each side of the first trench and the second trench surrounding the element region is longer than the pitch between the plurality of photoelectric conversion elements.

15. The solid-state imaging device according to claim 9 or 10, further comprising: A light shielding film is disposed inside the second groove.

16. The solid-state imaging device according to claim 15, wherein: The light shielding film is made of the same material as that of the first electrode.

17. The solid-state imaging device according to claim 15, wherein: The light shielding film is in contact with the first semiconductor region.

18. The solid-state imaging device according to claim 15, further comprising: An insulating film is provided between the light shielding film and the first semiconductor region.

19. An electronic device comprising: Solid-state camera device; An optical system that forms an image on a light receiving surface of the solid-state imaging device by incident light; and a processor controlling the solid-state imaging device, Wherein, the solid-state imaging device is a solid-state imaging device according to any one of claims 1 to 18.

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