Camera devices and electronic equipment

Abstract

The present technology relates to an imaging device and an electronic device capable of suppressing dark current. They include: a photoelectric conversion unit configured to perform photoelectric conversion; a groove dug in a semiconductor substrate; a negative fixed charge film composed of an oxide film, a nitrogen film and an oxide film on the side wall of the groove; and an electrode film formed in the fixed charge film. The oxide film used to constitute the fixed charge film includes SiO (silicon monoxide), and the nitrogen film used to constitute the fixed charge film includes SiN (silicon nitride). The nitrogen film used to constitute the fixed charge film may also include a polysilicon film or a high-k film (high dielectric constant film). The present technology can be applied to, for example, a back-illuminated CMOS image sensor.

Description

Technical Field

[0001] The present technology relates to an imaging device and an electronic device, and particularly to an imaging device and an electronic device capable of suppressing dark current. Background Art

[0002] A complementary metal oxide semiconductor (CMOS) image sensor provided in a solid-state imaging device generally includes devices such as photodiodes and transistors arranged corresponding to each pixel. In addition, as a CMOS image sensor, the following two structures have been proposed (please refer to Patent Document 1): one structure includes a deep trench isolation (DTI) located between each pixel for electrically isolating adjacent pixels, and the other structure includes a sub-contact for conducting static electricity charged in the pixel to the outside of the pixel.

[0003] If each pixel is provided with a DTI and a sub-contact, the device formation area in each pixel is reduced. A structure has been proposed to increase the device formation area in each pixel and discharge static electricity charged in the pixel to the outside of the pixel (see Patent Document 2).

[0004] The solid-state imaging device in Patent Document 2 is configured to include: a photodiode; a pixel isolation portion; a conductive member; and an insulating film covering the circumferential surface of the conductive member except for a portion on the other surface side of the conductive member. The end of the conductive member is connected to the ground.

[0005] Citation list

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-96490

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-54890 Summary of the invention

[0009] [Problems to be Solved by the Invention]

[0010] It is also currently desirable to suppress dark current in image sensors.

[0011] The present technology has been made in view of the above-described circumstances, and the present technology can achieve suppression of dark current.

[0012] [Technical solution to the problem]

[0013] According to one aspect of the present technology, there is provided an imaging device comprising: a photoelectric conversion unit configured to perform photoelectric conversion; a groove dug in a semiconductor substrate; a negative fixed charge film composed of an oxide film, a nitrogen film and an oxide film on a side wall of the groove; and an electrode film formed in the fixed charge film.

[0014] According to one aspect of the present technology, there is provided an electronic device equipped with the above-mentioned imaging device.

[0015] In an imaging device according to one aspect of the present technology, it includes: a photoelectric conversion unit configured to perform photoelectric conversion; a groove dug in a semiconductor substrate; a negative fixed charge film composed of an oxide film, a nitrogen film and an oxide film on the side wall of the groove; and an electrode film formed in the fixed charge film.

[0016] In an electronic device according to one aspect of the present technology, the above-mentioned imaging device is provided.

[0017] [Beneficial effects of the present invention]

[0018] According to an aspect of the present technology, dark current can be suppressed.

[0019] Incidentally, the effects described here are not restrictive, and any effects described in the present disclosure can be exerted. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram showing a configuration example of an image pickup device.

[0021] Figure 2 : is a diagram showing a configuration example of an image pickup device.

[0022] Figure 3 : is a vertical cross-sectional view showing one configuration example of a pixel to which the present technology is applied.

[0023] Figure 4 It is a plan view of the front surface side of a pixel to which the present technology is applied.

[0024] Figure 5 It is the circuit diagram of a pixel.

[0025] Figure 6 It is a diagram for explaining the structure of the fixed charge film.

[0026] Figure 7 is a vertical cross-sectional view showing another configuration example of a pixel.

[0027] Figure 8 is a vertical cross-sectional view showing still another configuration example of a pixel.

[0028] Fig. 9 It is a diagram for explaining the arrangement of contacts.

[0029] Fig.10 It is a diagram for explaining the arrangement of contacts.

[0030] Fig.11 It is a diagram for explaining the arrangement of contacts.

[0031] Fig.12 is a diagram for explaining a manufacturing process of a pixel.

[0032] Fig.13 : is a diagram showing an outline of a configuration example of a stacked solid-state imaging device to which the technology related to the present disclosure can be applied.

[0033] Fig.14 : is a cross-sectional view showing a first configuration example of the stacked solid-state imaging device 23020.

[0034] Fig.15 : is a cross-sectional view showing a second configuration example of the stacked solid-state imaging device 23020.

[0035] Fig.16 is a cross-sectional view showing a third configuration example of the stacked solid-state imaging device 23020.

[0036] Fig.17 is a cross-sectional view showing another configuration example of a stacked solid-state imaging device to which the technology related to the present disclosure can be applied.

[0037] Fig.18 is a block diagram showing an example of a schematic configuration of an in-vivo information acquisition system.

[0038] Fig.19 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0039] Fig. 20 1 is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection unit and the imaging unit. DETAILED DESCRIPTION

[0040] Hereinafter, a mode for carrying out the present technology (hereinafter referred to as an embodiment) will be described.

[0041] The present technology can be applied to a camera. Therefore, the description is given here by taking the case where the present technology is applied to a camera as an example. By the way, the description here continues by taking a camera as an example. However, the present technology is not limited to application to a camera, and can also be applied to electronic devices that generally use a camera as an image capture unit (photoelectric conversion unit), such as: a camera such as a digital camera and a video camera, a portable terminal device with a camera function such as a portable phone, a copier that uses a camera as an image reading unit, etc. By the way, there is also the following case: a module form (i.e., a camera module) installed on an electronic device can also be assumed to be a camera.

[0042] Figure 1 1 is a block diagram showing a configuration example of an image pickup device as an example of an electronic device of the present disclosure. Figure 1 As shown, the camera apparatus 10 includes: an optical system including a lens group 11, etc.; an image pickup device 12; a DSP circuit 13 as a camera signal processing unit; a frame memory 14; a display unit 15; a recording unit 16; an operating system 17; and a power supply system 18, etc.

[0043] In addition, in the above configuration, the DSP circuit 13, frame memory 14, display unit 15, recording unit 16, operation system 17 and power supply system 18 are mutually connected via bus 19. CPU (Central Processing Unit) 20 controls each component in the imaging device 10.

[0044] The lens group 11 captures incident light (image light) from a subject to form an image on an imaging surface of the imaging device 12. The imaging device 12 converts the amount of incident light that has been imaged on the imaging surface through the lens group 11 into an electrical signal in units of pixels, and outputs the electrical signal as a pixel signal. As the imaging device 12, an imaging device (image sensor) including pixels described later can be used.

[0045] The display unit 15 includes a panel type display unit such as a liquid crystal display unit or an organic electroluminescence (EL: electroluminescence) display unit, and displays a moving image or a still image picked up by the imaging device 12. The recording unit 16 records the moving image or the still image picked up by the imaging device 12 in a recording medium such as a video tape or a digital versatile disk (DVD: digital versatile disk).

[0046] The operating system 17 issues operation instructions related to various functions of the present camera under the operation of the user. The power supply system 18 appropriately supplies various power sources as operating power sources for the DSP circuit 13, frame memory 14, display unit 15, recording unit 16 and operating system 17 to these power supply targets.

[0047] <Structure of Imaging Device>

[0048] Figure 2 2 is a block diagram showing a configuration example of the image pickup device 12. The image pickup device 12 may be a complementary metal oxide semiconductor (CMOS) image sensor.

[0049] The imaging device 12 is configured to include a pixel array unit 41, a vertical drive unit 42, a column processing unit 43, a horizontal drive unit 44, and a system control unit 45. The pixel array unit 41, the vertical drive unit 42, the column processing unit 43, the horizontal drive unit 44, and the system control unit 45 are formed on a semiconductor substrate (chip) not shown.

[0050] In the pixel array unit 41, unit pixels (eg, Figure 3 The pixels 110 in the image sensor are arranged in a two-dimensional matrix form, and the photoelectric conversion device generates photocharges having a charge amount corresponding to the amount of incident light and accumulates these photocharges internally. Incidentally, in some cases below, the photocharges having a charge amount corresponding to the amount of incident light are simply referred to as "charges", and the unit pixel is simply referred to as "pixel".

[0051] Furthermore, in the matrix pixel arrangement within the pixel array unit 41, pixel drive lines 46 are formed corresponding to each row along the left-right direction in the figure (the pixel arrangement direction of the pixel row), and vertical signal lines 47 are formed corresponding to each column along the up-down direction in the figure (the pixel arrangement direction of the pixel column). One end of the pixel drive line 46 is connected to the output end of the vertical drive unit 42 corresponding to each row.

[0052] The imaging device 12 further includes a signal processing unit 48 and a data storage unit 49. The signal processing unit 48 and the data storage unit 49 may be processed by an external signal processing unit (e.g., a digital signal processor (DSP) or software, etc.) provided on a substrate different from the substrate of the imaging device 12, or may be installed on the same substrate as the substrate of the imaging device 12.

[0053] The vertical driving unit 42 includes a shift register, an address decoder, etc., and is a pixel driving unit that drives each pixel of the pixel array unit 41 simultaneously or in a row unit, etc. Although illustration of a specific structure is omitted, the vertical driving unit 42 is configured to include a readout scanning system and a sweep scanning system, or to include batch sweep and batch transfer.

[0054] The readout scanning system sequentially selects and scans the unit pixels of the pixel array unit 41 in units of rows to read out signals from the unit pixels. In the case of row driving (rolling shutter operation), in terms of sweeping, the readout row for which the readout scanning is performed by the readout scanning system is scanned at a time earlier than the readout scanning by the time length of the shutter speed. In addition, in the case of global exposure (global shutter operation), batch scanning is performed at a time earlier than batch transfer by the time length of the shutter speed.

[0055] The sweep operation causes the photoelectric conversion device in the unit pixel of the readout row to be swept away from unnecessary charges (reset). In addition, the sweeping (resetting) of unnecessary charges allows the so-called electronic shutter operation. Here, the electronic shutter operation means the operation of discarding the photoelectric conversion device's photoelectric charge and starting a new exposure (starting the accumulation of photoelectric charge).

[0056] The signal read out by the readout operation of the readout scanning system corresponds to the amount of light incident after the immediately previous readout operation or the electronic shutter operation. In the case of row driving, the period from the readout moment of the immediately previous readout operation or the sweep moment of the electronic shutter operation to the readout moment of the current readout operation is the accumulation period (exposure period) of the photocharge in the unit pixel. In the case of global exposure, the period from batch sweep to batch transfer is the accumulation period (exposure period).

[0057] The pixel signals output from the respective unit pixels in the pixel row selected and scanned by the vertical driving unit 42 are supplied to the column processing unit 43 via the respective vertical signal lines 47. Corresponding to the respective pixel columns of the pixel array unit 41, the column processing unit 43 performs predetermined signal processing on the pixel signals output from the respective unit pixels of the selected row via the vertical signal lines 47, and temporarily holds the pixel signals after the signal processing.

[0058] Specifically, as signal processing, the column processing unit 43 performs at least a noise reduction process such as a correlated double sampling (CDS) process. The correlated double sampling performed by the column processing unit 43 allows reduction of reset noise and fixed pattern noise inherent to pixels, such as a threshold difference of an amplifier transistor, etc. Incidentally, the column processing unit 43 may also be caused to have, for example, an analog-to-digital (AD) conversion function in addition to the noise reduction process, and output a signal level as a digital signal.

[0059] The horizontal driving unit 44 includes a shift register and an address decoder, etc., and sequentially selects the unit circuits corresponding to the pixel columns of the column processing unit 43. The selection scanning of the horizontal driving unit 44 allows the pixel signals processed by the column processing unit 43 to be sequentially output to the signal processing unit 48.

[0060] The system control unit 45 includes a timing generator for generating various timing signals and the like, and controls driving of, for example, the vertical driving unit 42 , the column processing unit 43 , and the horizontal driving unit 44 based on the various timing signals generated by the timing generator.

[0061] The signal processing unit 48 has at least an addition processing function, and performs various signal processing such as addition processing on the pixel signal output from the column processing unit 43. When signal processing is performed in the signal processing unit 48, the data storage unit 49 temporarily stores data necessary for the processing.

[0062] <Unit Pixel Structure>

[0063] Next, a description is given of a specific structure of the unit pixels 110 arranged in a matrix form in the pixel array unit 41 .

[0064] Figure 3 is a cross-sectional view showing a configuration example of a solid-state imaging device to which the technology related to the present disclosure can be applied.

[0065] In the solid-state imaging device, a photodiode (PD) 119 constituting a pixel 110 receives incident light 101 incident from the back side (upper surface in the figure) of a semiconductor substrate 118. A flattening film 113, a color filter (CF) 112, and a microlens 111 are provided above the PD 119. In the PD 119, the incident light 101 that has sequentially passed through the respective parts and entered is received by a light receiving surface 117 to perform photoelectric conversion.

[0066] For example, in PD 119, n-type semiconductor region 120 is formed as a charge accumulation region for accumulating charges (electrons). In PD 119, n-type semiconductor region 120 is disposed inside p-type semiconductor regions 116 and 141 of semiconductor substrate 118. P-type semiconductor region 141 having an impurity concentration higher than that on the back (upper surface) side is disposed on the front surface (lower surface) side of semiconductor substrate 118 of n-type semiconductor region 120. In other words, PD 119 has a hole accumulation diode (HAD; hole-accumulation diode) structure, and p-type semiconductor regions 116 and 141 are formed at each interface with the upper surface side and the lower surface side of n-type semiconductor region 120 to prevent generation of dark current.

[0067] A pixel isolation portion 130 for electrically isolating the plurality of pixels 110 is provided inside the semiconductor substrate 118. The PD 119 is provided in a region partitioned by the pixel isolation portion 130. When the solid-state imaging device is viewed from the upper surface side in the figure, the pixel isolation portion 130 is arranged between the plurality of pixels 110 and formed in a lattice shape, for example. The PD 119 is formed in a region partitioned by the pixel isolation portion 130.

[0068] In each PD 119, the anode is grounded. In the solid-state imaging device, signal charges (e.g., electrons) accumulated in the PD 119 are read out via, for example, a transfer transistor Tr (MOS FET) not shown, and output as an electrical signal to a vertical signal line (VSL) not shown.

[0069] The wiring layer 150 is provided on the front surface (lower surface) of the semiconductor substrate 118 which is opposite to the back surface (upper surface) on which the respective portions such as the light shielding film 114 , the CF 112 , and the microlens 111 are provided.

[0070] The wiring layer 150 includes wiring 151 and an insulating layer 152. In the insulating layer 152, the wiring 151 is formed in such a manner as to be electrically connected to each device. The wiring layer 150 is a so-called multilayer wiring layer, and is formed by alternately stacking the wiring 151 and the interlayer insulating film for constituting the insulating layer 152 multiple times. Here, as the wiring 151, various wirings such as wiring of a transistor Tr (for example, a transfer transistor Tr, etc.) for reading out charge from the PD 119, and VSL are stacked with the aid of the insulating layer 152.

[0071] The support substrate 161 is provided on one surface of the wiring layer 150, the one surface being opposite to the side provided with the PD 119. As the support substrate 161, for example, a substrate including a silicon semiconductor having a thickness of several hundred micrometers is provided.

[0072] The light shielding film 114 is provided on the back surface (upper surface in the figure) side of the semiconductor substrate 118 .

[0073] The light shielding film 114 is configured to block a portion of the incident light 101 that propagates from above the semiconductor substrate 118 to below the semiconductor substrate 118 .

[0074] The light shielding film 114 is provided above the pixel isolation portion 130 provided inside the semiconductor substrate 118. Here, the light shielding film 114 is provided on the back surface (upper surface) of the semiconductor substrate 118 via an insulating film 115 such as a silicon oxide film, and protrudes in the form of a convexity. In contrast, the light shielding film 114 is not provided above the PD 119 provided inside the semiconductor substrate 118, but has an opening to allow the incident light 101 to be incident on the PD 119.

[0075] In other words, when the solid-state imaging device is viewed from the upper surface side in the figure, the planar shape of the light shielding film 114 is lattice-shaped, and openings are formed so as to let the incident light 101 pass through the openings to reach the light receiving surface 117 .

[0076] The light shielding film 114 includes a light shielding material that blocks light. For example, a titanium (Ti) film and a tungsten (W) film are stacked in sequence to form the light shielding film 114. In addition, the light shielding film 114 can also be formed by, for example, stacking a titanium nitride (TiN) film and a tungsten (W) film in sequence. In addition, the light shielding film 114 can be covered with nitride (N) or the like.

[0077] The light shielding film 114 is covered with the planarizing film 113. The planarizing film 113 is formed using an insulating material that allows light to pass therethrough.

[0078] The pixel isolation portion 130 includes a trench 131 , a fixed charge film 132 , and an electrode film 133 .

[0079] The fixed charge film 132 is formed so as to cover the groove 131 that divides the plurality of pixels 110 on the back surface (upper surface) side of the semiconductor substrate 118 .

[0080] Also refer to below Figure 6To explain the details, it is assumed that the fixed charge film 132 has a three-layer structure and is provided to cover the inner surface of the groove 131 formed on the front surface (lower surface) side in the semiconductor substrate 118 with a constant thickness. Then, the electrode film 133 is provided (filled) so as to be buried in the inside of the groove 131 covered by the fixed charge film 132.

[0081] Here, the fixed charge film 132 is formed using a high-k dielectric having negative fixed charges, so as to form a positive charge (hole) accumulation region in the interface portion with the semiconductor substrate 118 and prevent the occurrence of dark current. The fixed charge film 132 is formed to include negative fixed charges. Accordingly, the negative fixed charges allow an electric field to be applied to the interface with the semiconductor substrate 118. Thus, a positive charge (hole) accumulation region is formed.

[0082] Reference Figure 4 and Figure 5 The arrangement of each transistor formed in the pixel 110 and the operation of each transistor are described. Figure 4 is arranged in the pixel array unit 41 ( Figure 2 ) of the 3×3 pixels 110 in total when viewed from the front surface side ( Figure 3 , a plan view when observed from the lower side of the figure). Figure 5 It is used to illustrate Figure 4 A circuit diagram showing the connection relationship of each transistor shown.

[0083] exist Figure 4 In FIG. 1 , one box represents one pixel 110. Figure 4 As shown, the groove 131 is formed to surround the pixel 110 (and also surround the PD 119 included in the pixel 110). In addition, a transfer transistor (gate) 190, a floating diffusion (FD) 191, a reset transistor 192, an amplifying transistor 193, and a selection transistor 194 are formed on the front surface side of the pixel 110.

[0084] The PD 119 generates charges (signal charges) corresponding to the amount of received light and accumulates the charges. An anode terminal of the PD 119 is grounded, and a cathode terminal of the PD 119 is connected to the FD 191 through the transfer transistor 190 .

[0085] When the transfer transistor 190 is turned on by the transfer signal TR, the transfer transistor 190 reads out the charge generated in the PD 119 and transfers the charge to the FD 191 .

[0086] The FD 191 holds the charge read out from the PD 119. When the reset transistor 192 is turned on by the reset signal RST, the reset transistor 192 resets the potential of the FD 191 by discharging the charge accumulated in the FD 191 to the drain (constant voltage source Vdd).

[0087] The amplifier transistor 193 outputs a pixel signal corresponding to the potential of the FD 191. In other words, the amplifier transistor 193 and a load MOS (not shown) as a constant current source connected via the vertical signal line 33 constitute a source follower. The amplifier transistor 193 transmits a pixel signal representing a level corresponding to the charge accumulated in the FD 191 to the column processing unit 43 ( Figure 2 ) output.

[0088] When the pixel 31 is selected by the selection signal SEL, the selection transistor 194 is turned on and the pixel signal of the pixel 31 is output to the column processing unit 43 via the vertical signal line 47. The signal lines for transmitting the transmission signal TR, the selection signal SEL and the reset signal RST correspond to Figure 2 Pixel drive line 46 in.

[0089] The pixel 110 may be configured as described above, but is not limited to this configuration, and may adopt other configurations.

[0090] <Structure of Fixed Charge Film>

[0091] Figure 6 is a diagram showing a specific configuration of the fixed charge film 132 .

[0092] The fixed charge film 132 is provided to cover the inner surface of the groove 131 formed on the front surface (lower surface in the figure) side in the semiconductor substrate 118 with a constant thickness. Then, the electrode film 133 is provided (filled) so as to be buried in the inside of the groove 131 covered by the fixed charge film 132.

[0093] The fixed charge film 132 is formed in the pixel isolation portion 130 and is formed into a three-layer structure. The three layers constituting the fixed charge film 132 include: a SiO (silicon monoxide) film 201, a SiN (silicon nitride) film 202, and a SiO film 203. In this way, the fixed charge film 132 is configured to sandwich a SiN film between SiO films. The fixed charge film 132 has a configuration similar to a charge accumulation film composed of an accumulation film (ONO film) of an oxide film-nitride film-oxide film.

[0094] The fixed charge film 132 can be caused to function as a charge accumulation film. The electrode film 133 is formed on the inner side of the fixed charge film 132. A voltage is applied to the electrode film 133; therefore, the fixed charge film 132 functions as a negative fixed charge film. The contact 171 is connected to the electrode film 133. Moreover, the contact 171 is connected to the wiring 151 in the wiring layer 150. The wiring 151 is connected to a power source and is configured such that a predetermined voltage is applied to the wiring at a predetermined timing.

[0095] The number of times the voltage is applied to the fixed charge film 132 may be once. For example, it may be configured such that the voltage is applied once when the pixel 110 is manufactured.

[0096] Furthermore, it may be configured such that a voltage is applied to the fixed charge film 132 at the time when the power of the imaging device including the pixel 110 is turned on. In the case of such a configuration, it may be configured such that a voltage is applied to the fixed charge film 132 every time the power of the imaging device is turned on.

[0097] If a voltage is applied to the fixed charge film 132 even once, the fixed charge film 132 starts to function as a charge film having negative fixed charges. The negative fixed charges allow an electric field to be applied to the interface with the semiconductor substrate 118. Thus, a positive charge (hole) accumulation region is formed, and a structure capable of preventing the occurrence of dark current can be obtained.

[0098] In this way, the fixed charge film 132 can be caused to function as the negative fixed charge film 132 by applying a voltage to the fixed charge film 132 at least once. Therefore, the negative fixed charge film 132 can be generated without power consumption.

[0099] The SiO film 201, the SiN film 202, and the SiO film 203 constituting the fixed charge film 132 may be formed with the same thickness or different thicknesses. Furthermore, the thickness of the SiO film 201 and the thickness of the SiO film 203 may be formed to be the same thickness, and the thickness of the SiO film 201 on the PD 119 side may be formed to be thinner than the thickness of the SiO film 203 on the inner side of the fixed charge film 132.

[0100] The fixed charge film 132 may be Figure 3 As shown in FIG. 1 , the fixed charge film 132 may be formed to reach a position where the upper portion of the fixed charge film 132 contacts the insulating film 115, or the fixed charge film 132 may be formed to reach a position where the upper portion of the fixed charge film 132 contacts the insulating film 115. Figure 7 The film is formed to reach a position where the upper portion of the fixed charge film 132 is not in contact with the insulating film 115 . Figure 7 The illustrated pixel 110 ′ has a structure in which a p-type semiconductor region 116 exists between an upper portion of a fixed charge film 132 and an insulating film 115 , and the upper portion of the fixed charge film 132 is not in contact with the insulating film 115 .

[0101] like Figure 7 As shown, the groove 131 may be formed without penetrating the semiconductor substrate 118. In this case, the fixed charge film 132 is also formed in the groove 131; therefore, it is possible to have the same Figure 3 As shown in the figure, the structure in which the generation of dark current can be prevented is the case where the trench 131 is formed in a state of penetrating the semiconductor substrate 118.

[0102] At once Figure 3 The pixel 110 and Figure 7 The illustrated pixel 110' shows an example in which the contact 171 is formed on the front surface side (the side opposite to the light incident side; the lower side in the figure). However, the contact 171 may be formed on the back surface side (the light incident side; the upper side in the figure).

[0103] Figure 8 FIG. 1 shows a configuration of a pixel 110 ″ in which a contact 171 ″ is formed on the back side. Figure 8 As shown, a contact 171 ″ is formed on the back side (light incident side). One end of the contact 171 ″ is connected to the electrode film 133 , and the other end is connected to the light shielding film 114 .

[0104] The light shielding film 114 includes a material that blocks light and may include a conductor such as a metal. The light shielding film 114 includes a conductor and is configured so that a predetermined voltage can be applied to the light shielding film 114. Therefore, a voltage can be applied to the electrode film 133 connected to the light shielding film 114 via the contact 171".

[0105] The contact 171 may be configured to be connected to the wiring 151 within the wiring layer 150 , or may be configured to be connected to the light shielding film 114 .

[0106] In addition, the contact 171 may be configured as follows Fig. 9 or Fig.10 The formation positions and formation quantities shown. Fig. 9 The case where the contacts 171 are arranged corresponding to the respective pixels 110 is shown. Fig.10 The structure in which a contact 171 is shared by a plurality of pixels 110 is shown. Fig. 9 and Fig.10 From e.g. Figure 3 The pixel 110 is shown in a plan view as viewed from the back side (upper side).

[0107] Fig. 9 It is shown that in the pixel array unit 41 ( Figure 2) are arranged in an array of 2×2 four pixels 110. One pixel 110 (PD 119) is surrounded by a groove 131. A fixed charge film 132 is formed in the groove 131. Therefore, one PD 119 is configured to be surrounded by the fixed charge film 132.

[0108] A contact 171 is formed at each of the four corners of one pixel 110. The contact 171 formed at the four corners of the pixel 110 is connected to the wiring 151 ( Figure 3 ). The wiring 151 is connected to a power supply voltage.

[0109] Refer again Figure 3 In the cross-sectional view of the pixel 110 shown in FIG. 1 , the electrode film 133 is formed in the groove 131. Fig. 9 In the plan view of the pixel 110 shown in FIG. 1 , the electrode film 133 is formed to surround the pixel 110, and the electrode film 133 formed around each pixel 110 is formed continuously with the electrode film 133 formed around the adjacent pixel 110. In other words, the electrode film 133 formed in the pixel array unit 41 is formed continuously and without interruption.

[0110] So, we can Fig. 9 As shown, the contact 171 is formed corresponding to each pixel 110, but it can also be as shown in FIG. Fig.10 As shown, a contact 171 is formed corresponding to each group consisting of a plurality of pixels 110. Fig.10 The pixel 110 shown is configured such that a plurality of pixels 110 arranged in a row direction share one contact 171. In addition, the contact 171 is provided at an end of the pixel array unit 41.

[0111] Fig.10 The structure in which a plurality of pixels 110 arranged in the row direction share one contact 171 is shown. However, as described above, the electrode film 133 formed in the pixel array unit 41 is formed continuously. Accordingly, it can also be configured here that all pixels 110 of the pixel array unit 41 share one contact 171. For example, in Fig.10 , three contacts 171 are shown. However, it is also possible to have a configuration, not shown, in which only the contacts 171 shown at the upper portion are formed, for example.

[0112] In addition, Fig. 9 and Fig.10 In the structure of FIG. 1 , each pixel 110 is surrounded by a groove 131 (a fixed charge film 132 and an electrode film 133 formed in the groove 131). Fig.11 As shown, it may also be configured that the pixel 110 is not completely surrounded by the trench 131 , but is partially surrounded by the trench 131 .

[0113] If the image Fig. 9 and Fig.10 The structure in which the groove 131 is formed to completely surround the pixel 110 as in the pixel 110 shown in FIG. 1 (i.e., the structure in which the pixel isolation portion 130 is formed to completely surround the pixel 110) is called pixel complete isolation. Fig.11 The illustrated pixel 110 has a structure in which the pixel is not completely isolated.

[0114] Fig.11 Among the four sides around the pixel 110, three sides with the pixel isolation portion 130 (electrode film 133 in the groove 131) are continuously formed, but the remaining side is not connected. The three continuously formed sides are connected to a contact 171. Fig.11 In the example shown, it is configured so that a plurality of pixels 110 arranged in the row direction share one contact 171 .

[0115] like Fig. 9 and Fig.10 As in the example shown, all pixel separation portions 130 (electrode films 133) in the pixel array unit 41 may be formed in a connected state, or as in Fig.11 As shown in the example, all the electrode films 133 in the pixel array unit 41 may be formed in a partially cut shape instead of being formed in a connected state. Furthermore, the number of contacts 171 and the formation positions of the contacts 171, etc., need only be appropriately set depending on whether the electrode film 133 is formed continuously or discontinuously, or whether the same voltage is applied to all pixels or different voltages are applied to each pixel (according to a predetermined number), or other factors.

[0116] <About pixel manufacturing>

[0117] Will refer to Fig.12 The manufacturing of pixel 110 is further described.

[0118] In step S101, a front end of line (FEOL) process is performed. In the FEOL process, a transistor (eg, a transfer transistor 190 ( Figure 4 ) etc. In addition, in step S101, PD 119 etc. are also formed in semiconductor substrate 118. In addition, in step S101, groove 131 is also formed. The groove 131 can be formed by photolithography and dry etching.

[0119] In step S102, the fixed charge film 132 is deposited, and the electrode film 133 is deposited. As described above, the fixed charge film 132 includes the SiO film 201, the SiN film 202, and the SiO film 203 deposited in sequence. Then, the electrode film 133 is deposited (filled with a material for forming the electrode film 133).

[0120] After the above deposition, etching back is performed to form a MONOS structure. The MONOS structure is a metal-oxide-nitride-oxide-silicon structure, and is a structure in which three layers of oxide film / nitride film / oxide film (in this case, corresponding to the fixed charge film 132) are formed on a silicon substrate, and electrodes (metal; in this case, corresponding to the electrode film 133) are arranged on these three layers.

[0121] As a material for forming the electrode film 133, a metal such as tungsten (W), or polysilicon, etc. can be used. In addition, the above description assumes that the SiO film 201, the SiN film 202, and the SiO film 203 are used as the fixed charge film 132. However, the ONO film may include a combination of materials other than SiO and SiN. For example, the SiN film 202 (nitride film) may not be SiN, but may also be formed of a polysilicon (Poly-Si) film or a high dielectric constant film (high-k film).

[0122] If it is assumed that the SiN film 202 is a high-k film, as a material of the high-k film, oxides such as hafnium, zirconium, aluminum, tantalum, titanium, magnesium, yttrium, and lanthanoid elements can be used.

[0123] In step S103, a back end of line (BEOL) process is performed. In the BEOL process, the wiring 151 in the wiring layer 150 of the pixel 110 is formed. In this step S103, a contact 171 connected to the electrode film 133 is formed, and the contact is connected to the wiring 151. In addition, a structure to which a voltage can be applied is formed.

[0124] In this step S103 , at the point in time when a structure to which a voltage can be applied is formed, a voltage may be applied to the fixed charge film 132 to generate a negative fixed charge film, or the voltage may be applied in a later step.

[0125] In step S104 , a color filter (CF) 112 , an OCL (On Chip Lens) 111 , and the like are formed.

[0126] In this way, the fixed charge film 132 is formed, and the pixel 110 including the fixed charge film 132 is manufactured. Such steps are merely examples. These steps may be changed in order, or the film deposition process and the like may be performed by other methods.

[0127] As described above, the fixed charge film 132 includes three layers. When the fixed charge film 132 is deposited, no heat treatment is required, especially no treatment at a high temperature is required. Therefore, for example, a metal with poor high temperature tolerance can be used as a wiring, or the fixed charge film 132 can be formed after such wiring is formed. Therefore, the pixel 110 including the fixed charge film 132 can be manufactured without increasing the number of steps. In addition, a reduction in productivity can be prevented.

[0128] The present technology allows the fixed charge film 132 to be formed with an ONO film, and allows a configuration to be obtained in which electrons can be trapped in the charge accumulation layer of the ONO film. Therefore, the occurrence of dark current can be prevented.

[0129] Incidentally, the fixed charge film 132 to which the present technology is applied can also be provided to a vertical spectral pixel and an avalanche photodiode. The application range is not limited to the above-mentioned pixel 110.

[0130] <Other Modifications>

[0131] The pixel 110 to which the present technology is applied can also be applied to a pixel configured by stacking a plurality of substrates as described below, for example.

[0132] <Configuration Example of Stacked Solid-State Image Capturing Device to Which the Technology Related to the Present Disclosure Can Be Applicable>

[0133] Fig.13 : is a diagram showing an outline of a configuration example of a stacked solid-state imaging device to which the technology related to the present disclosure can be applied.

[0134] Fig.13 A shows a schematic configuration example of a non-stacked solid-state imaging device. The solid-state imaging device 23010 includes Fig.13 A chip (die) (semiconductor substrate) 23011 is shown in FIG. The chip 23011 is provided with: a pixel area 23012 for arranging a pixel array; a control circuit 23013 for performing pixel driving and other various controls; and a logic circuit 23014 for signal processing.

[0135] Fig.13 B and C show schematic configuration examples of stacked solid-state imaging devices. Fig.13As shown in B and C of FIG. 1 , the solid-state imaging device 23020 is constructed as one semiconductor chip by stacking two chips, a sensor chip 23021 and a logic chip 23024, and electrically connecting the two chips.

[0136] exist Fig.13 In FIG. 2B , a pixel region 23012 and a control circuit 23013 are mounted on a sensor wafer 23021 . A logic circuit 23014 including a signal processing circuit for performing signal processing is mounted on a logic wafer 23024 .

[0137] exist Fig.13 In FIG. 2C, the pixel region 23012 is mounted on the sensor wafer 23021. The control circuit 23013 and the logic circuit 23014 are mounted on the logic wafer 23024.

[0138] Fig.14 : is a cross-sectional view showing a first configuration example of the stacked solid-state imaging device 23020.

[0139] A photodiode (PD), a floating diffusion (FD), a transistor Tr (MOS FET) for constituting a pixel to be the pixel region 23012, and a transistor Tr to be the control circuit 23013 are formed on the sensor wafer 23021. In addition, a wiring layer 23101 including a plurality of layers (three layers in this example) of wiring 23110 is formed in the sensor wafer 23021. Incidentally, the control circuit 23013 (the transistor Tr to be the control circuit 23013) may be arranged not in the sensor wafer 23021 but in the logic wafer 23024.

[0140] A transistor Tr for constituting a logic circuit 23014 is formed in the logic wafer 23024. In addition, a wiring layer 23161 including a plurality of layers (three layers in this example) of wiring 23170 is formed in the logic wafer 23024. Moreover, a connection hole 23171 having an insulating film 23172 formed on an inner wall surface thereof is formed in the logic wafer 23024. In the connection hole 23171, a connection conductor 23173 connected to the wiring 23170 and the like is buried.

[0141] The sensor wafer 23021 and the logic wafer 23024 are bonded together in such a manner that the wiring layer 23101 and the wiring layer 23161 face each other. Thus, a stacked solid-state imaging device 23020 is constructed in which the sensor wafer 23021 and the logic wafer 23024 are stacked. A film 23191 such as a protective film is formed on the surface where the sensor wafer 23021 and the logic wafer 23024 are bonded together.

[0142] A connection hole 23111 is formed in the sensor wafer 23021, and the connection hole 23111 penetrates the sensor wafer 23021 from the back side (the side where light is incident on the PD) (upper side) of the sensor wafer 23021 to reach the uppermost wiring 23170 in the logic wafer 23024. In addition, a connection hole 23121 is formed near the connection hole 23111 in the sensor wafer 23021, and the connection hole 23121 reaches the first layer wiring 23110 from the back side of the sensor wafer 23021. An insulating film 23112 is formed on the inner wall surface of the connection hole 23111. An insulating film 23122 is formed on the inner wall surface of the connection hole 23121. Then, connection conductors 23113 and 23123 are buried in the connection holes 23111 and 23121, respectively. The connection conductors 23113 and 23123 are electrically connected on the back side of the sensor wafer 23021. Therefore, the sensor chip 23021 and the logic chip 23024 are electrically connected via the wiring layer 23101 , the connection hole 23121 , the connection hole 23111 , and the wiring layer 23161 .

[0143] Fig.15 : is a cross-sectional view showing a second configuration example of the stacked solid-state imaging device 23020.

[0144] In the second construction example of the solid-state imaging device 23020, a connection hole 23211 formed in the sensor chip 23021 electrically connects the sensor chip 23021 (its wiring layer 23101 (wiring 23110 therein) and the logic chip 23024 (its wiring layer 23161 (wiring 23170 therein).

[0145] In other words, Fig.15 In the embodiment, a connection hole 23211 is formed, which penetrates the sensor wafer 23021 from the back side of the sensor wafer 23021 to reach the uppermost wiring 23170 in the logic wafer 23024, and reaches the uppermost wiring 23110 in the sensor wafer 23221. An insulating film 23212 is formed on the inner wall surface of the connection hole 23211. A connection conductor 23213 is buried in the connection hole 23211. In the above Fig.14 In FIG. 2 , two connection holes 23111 and 23121 electrically connect the sensor chip 23021 and the logic chip 23024. Fig.15 In the figure, a connection hole 23211 electrically connects the sensor chip 23021 and the logic chip 23024.

[0146] Fig.16 is a cross-sectional view showing a third configuration example of the stacked solid-state imaging device 23020.

[0147] Fig.16 The solid-state imaging device 23020 and Fig.14 The difference between the case where a film 23191 such as a protective film is formed on the surface where the sensor chip 23021 and the logic chip 23024 are bonded together is that a film 23191 such as a protective film is not formed on the surface where the sensor chip 23021 and the logic chip 23024 are bonded together.

[0148] Fig.16 The solid-state imaging device 23020 is constructed as follows: the sensor chip 23021 and the logic chip 23024 are placed on top of each other so that the wiring 23110 and the wiring 23170 are in direct contact with each other, and the wiring 23110 and the wiring 23170 are directly bonded while heating is performed while applying the required weight.

[0149] Fig.17 is a cross-sectional view showing another configuration example of a stacked solid-state imaging device to which the technology related to the present disclosure can be applied.

[0150] exist Fig.17 In the figure, the solid-state imaging device 23401 has a three-layer stacked structure: in which three chips, namely a sensor chip 23411, a logic chip 23412 and a memory chip 23413, are stacked.

[0151] The memory chip 23413 includes, for example, a memory circuit that stores data temporarily required when signal processing is performed in the logic chip 23412.

[0152] exist Fig.17 , the logic chip 23412 and the memory chip 23413 are stacked in this order below the sensor chip 23411. However, the logic chip 23412 and the memory chip 23413 may be stacked in the opposite order, that is, the memory chip 23413 and the logic chip 23412 are stacked below the sensor chip 23411 in this order.

[0153] By the way, in Fig.17 In the sensor wafer 23411, a PD to be a photoelectric conversion unit of a pixel and a source region and a drain region of a pixel transistor Tr are formed.

[0154] A gate electrode is formed around the PD via a gate insulating film. The pixel transistor Tr 23421 and the pixel transistor Tr 23422 are formed by the gate electrode and a pair of source and drain regions.

[0155] The pixel transistor Tr 23421 adjacent to the PD is a transfer transistor Tr, and one of a pair of source regions and drain regions constituting the pixel transistor Tr23421 functions as an FD.

[0156] In addition, an interlayer insulating film is formed in the sensor wafer 23411. A connection hole is formed in the interlayer insulating film. A connection conductor 23431 connected to the pixel transistor Tr 23421 and the pixel transistor Tr 23422 is formed in the connection hole.

[0157] Furthermore, a wiring layer 23433 including multilayer wirings 23432 connected to the respective connection conductors 23431 is formed in the sensor wafer 23411 .

[0158] In addition, an aluminum pad 23434 to be an external connection electrode is formed in the bottom layer of the wiring layer 23433 of the sensor wafer 23411. In other words, the aluminum pad 23434 is formed at a position closer to the bonding surface 23440 of the logic wafer 23412 than the wiring 23432 in the sensor wafer 23411. The aluminum pad 23434 is used as one end of a wiring related to input of a signal from the outside and / or output of a signal to the outside.

[0159] Furthermore, a contact 23441 for electrical connection with the logic chip 23412 is formed in the sensor wafer 23411. The contact 23441 is connected to a contact 23451 of the logic chip 23412, and is also connected to an aluminum pad 23442 of the sensor wafer 23411.

[0160] Then, a pad hole 23443 is formed in the sensor wafer 23411 , which reaches the aluminum pad 23442 from the back side (upper side) of the sensor wafer 23411 .

[0161] The technology related to the present disclosure can be applied to such a solid-state imaging device as described above.

[0162] <Application examples of in vivo information acquisition system>

[0163] The technology related to the present disclosure (the present technology) can be applied to various products. For example, the technology related to the present disclosure can be applied to an endoscopic surgery system.

[0164] Fig.18 : is a block diagram showing an example of a schematic configuration of a patient in vivo information acquisition system using a capsule-type endoscope to which a technology related to the present disclosure (the present technology) can be applied.

[0165] The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200 .

[0166] The capsule endoscope 10100 is swallowed by the patient during the examination. The capsule endoscope 10100 has an imaging function and a wireless communication function. Before being naturally discharged from the patient's body, the capsule endoscope 10100 moves inside organs such as the stomach and intestines by peristalsis, etc., and sequentially captures images of the inside of these organs (hereinafter referred to as in-vivo images) at predetermined intervals, and sequentially and wirelessly transmits information about the in-vivo images to the external control device 10200 outside the body.

[0167] The external control device 10200 comprehensively controls the operation of the in-vivo information acquisition system 10001. In addition, the external control device 10200 receives information about in-vivo images sent from the capsule endoscope 10100, and generates image data for displaying the in-vivo images on a display device (not shown) based on the received information about the in-vivo images.

[0168] In the in-vivo information acquisition system 10001, in-vivo images can be obtained by capturing images of the patient's internal body at any time during the period from swallowing to excretion of the capsule endoscope 10100.

[0169] The structure and function of the capsule endoscope 10100 and the external control device 10200 will be described in more detail below.

[0170] The capsule endoscope 10100 has a capsule-shaped casing 10101. The casing 10101 accommodates a light source unit 10111, an imaging unit 10112, an image processing unit 10113, a wireless communication unit 10114, a power transmission unit 10115, a power supply unit 10116, and a control unit 10117.

[0171] The light source unit 10111 includes, for example, a light source such as a light emitting diode (LED), and irradiates light to the imaging field of the imaging unit 10112 .

[0172] The imaging unit 10112 includes: an imaging device; and an optical system having a plurality of lenses disposed upstream of the imaging device. Reflected light (hereinafter referred to as observation light) of light irradiated to a specific body tissue as an observation object is converged by the optical system and incident on the imaging device. In the imaging device in the imaging unit 10112, the observation light incident on the imaging device is photoelectrically converted to generate an image signal corresponding to the observation light. The image signal generated by the imaging unit 10112 is provided to the image processing unit 10113.

[0173] The image processing unit 10113 includes a processor such as a central processing unit (CPU) or a graphics processing unit (GPU), and performs various signal processing on the image signal generated by the imaging unit 10112. The image processing unit 10113 supplies the image signal after the signal processing to the wireless communication unit 10114 as RAW data.

[0174] The wireless communication unit 10114 performs predetermined processing such as modulation processing on the image signal subjected to signal processing by the image processing unit 10113, and transmits the image signal to the external control device 10200 via the antenna 10114A. In addition, the wireless communication unit 10114 receives a control signal related to the drive control of the capsule endoscope 10100 from the external control device 10200 via the antenna 10114A. The wireless communication unit 10114 provides the control signal received from the external control device 10200 to the control unit 10117.

[0175] The power transmission unit 10115 includes: an antenna coil for power reception; a power regeneration circuit for regenerating power from the current generated in the antenna coil; a boost converter circuit, etc. In the power transmission unit 10115, power is generated using a principle called inductive charging.

[0176] The power supply unit 10116 includes a rechargeable battery and stores the power generated by the power transmission unit 10115. Fig.18 In order to avoid complicating the drawings, schematic illustrations such as arrows indicating the supply destination of the power from the power supply unit 10116 are omitted. However, the power stored in the power supply unit 10116 is supplied to the light source unit 10111, the camera unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117, and can be used to drive them.

[0177] The control unit 10117 includes a processor such as a CPU, and appropriately controls the driving of the light source unit 10111 , the imaging unit 10112 , the image processing unit 10113 , the wireless communication unit 10114 , and the power transmission unit 10115 according to a control signal sent from the external control device 10200 .

[0178] The external control device 10200 includes: a processor such as a CPU or a GPU, or a microcomputer or a control board equipped with a storage device such as a processor and a memory in combination, etc. The external control device 10200 sends a control signal to the control unit 10117 of the capsule endoscope 10100 via the antenna 10200A to control the action of the capsule endoscope 10100. In the capsule endoscope 10100, for example, the control signal from the external control device 10200 allows the light irradiation conditions for the observation object in the light source unit 10111 to be changed. In addition, the control signal from the external control device 10200 allows the imaging conditions (for example, the frame rate, the exposure value, etc. in the imaging unit 10112) to be changed. In addition, the control signal from the external control device 10200 can allow the processing content in the image processing unit 10113 and the transmission conditions of the image signal by the wireless communication unit 10114 (for example, the transmission interval, the number of images to be transmitted, etc.) to be changed.

[0179] In addition, the external control device 10200 performs various image processing on the image signal sent from the capsule endoscope 10100, and generates image data for displaying the captured in-vivo image on the display device. As the above-mentioned image processing, various signal processing such as the following can be performed: image processing (demosaic processing), image enhancement processing (for example, band response enhancement processing, super-resolution processing, noise reduction (NR; noise reduction) processing and / or hand shake correction processing) and / or magnification processing (electronic zoom processing) and the like. The external control device 10200 controls the driving of the display device, and causes the display device to display the in-vivo image captured based on the generated image data. Alternatively, the external control device 10200 can cause a recording device (not shown) to record the generated image data, or can cause a printing device (not shown) to print and output the generated image data.

[0180] Heretofore, an example of an in-vivo information acquisition system to which the technology related to the present disclosure can be applied has been described. The technology related to the present disclosure can be applied to the imaging unit 10112 in the above-described configuration.

[0181] <Application example of mobile object>

[0182] The technology related to the present disclosure (the present technology) can be applied to a variety of products. For example, the technology related to the present disclosure can be implemented as a device installed on any type of mobile body, such as a car, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal motor vehicle, an airplane, a drone, a ship, or a robot.

[0183] Fig.19: is a block diagram showing a schematic configuration example of a vehicle control system which is one example of a moving body control system to which the technology related to the present disclosure is applicable.

[0184] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. Fig.19 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside information detection unit 12030, an inside information detection unit 12040, and an integrated control unit 12050. In addition, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F; interface) 12053 are shown.

[0185] The drive system control unit 12010 controls the operation of devices related to the vehicle drive system according to various programs. For example, the drive system control unit 12010 functions as a control device for, for example, the following devices: a drive force generating device such as an internal combustion engine or a drive motor for generating a vehicle drive force; a drive force transmitting mechanism for transmitting the drive force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating a braking force for the vehicle.

[0186] The body system control unit 12020 controls the operation of various devices equipped to the vehicle according to various programs. For example, the body system control unit 12020 functions as a control device for the following devices, for example: a keyless entry system; a smart key system; a power window device; or various lights such as a headlight, a reverse light, a parking light, a turn signal, or a fog light. In this case, a radio wave or various switch signals emitted from a portable device instead of a key may be input into the body system control unit 12020. The body system control unit 12020 receives the input of the radio wave or the switch signal, and controls the door lock device, the power window device, or the light, etc. of the vehicle.

[0187] The vehicle exterior information detection unit 12030 detects information about the exterior of the vehicle on which the vehicle control system 12000 is installed. For example, the camera unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture an image of the exterior of the vehicle, and the vehicle exterior information detection unit 12030 also receives the captured image. The vehicle exterior information detection unit 12030 can perform object detection processing or distance detection processing on a person, a vehicle, an obstacle, a sign, text on a road surface, etc. based on the received image.

[0188] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 may output the electrical signal as an image, or may output the electrical signal as distance measurement information. In addition, the light received by the imaging unit 12031 may be visible light or may be non-visible light such as infrared rays.

[0189] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, a driver state detection unit 12041 for detecting the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera capable of photographing the driver. The in-vehicle information detection unit 12040 can calculate the driver's fatigue or concentration based on the detection information input from the driver state detection unit 12041, or can determine whether the driver is dozing off.

[0190] The microcomputer 12051 can calculate the control target value of the driving force generating device, the steering mechanism or the braking device based on the information about the inside or outside of the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and output the control instruction to the driving system control unit 12010. For example, the microcomputer 12051 can perform coordinated control for realizing the functions of the advanced driver assistance system (ADAS), which includes: collision avoidance or impact mitigation of the vehicle, following control based on the vehicle-to-vehicle distance, constant speed driving of the vehicle, vehicle collision warning, vehicle lane departure warning, etc.

[0191] In addition, the microcomputer 12051 can perform coordinated control for the purpose of automatic driving, such as autonomous driving without the need for driver operation, by controlling a driving force generating device, a steering mechanism, or a braking device, based on information about the vehicle's surroundings obtained by the external information detection unit 12030 or the internal information detection unit 12040.

[0192] Furthermore, the microcomputer 12051 may output a control instruction to the body system control unit 12020 based on the information about the exterior of the vehicle acquired by the exterior information detection unit 12030. For example, the microcomputer 12051 may control the headlights to switch from high beam to low beam according to the position of a preceding vehicle or an oncoming vehicle detected by the exterior information detection unit 12030, thereby performing coordinated control for the purpose of promoting glare prevention.

[0193] The sound / image output unit 12052 sends an output signal of at least one of sound and image to an output device, which can visually or auditorily notify the passengers of the vehicle or the outside of the vehicle of information. Fig.19 In the example of FIG. 1 , as output devices, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplarily shown. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0194] Fig. 20 12031 is a diagram showing an example of the installation position of the imaging unit 12031.

[0195] exist Fig. 20 In the figure, vehicle 12100 includes camera units 12101, 12102, 12103, 12104 and 12105 as camera unit 12031.

[0196] Camera units 12101, 12102, 12103, 12104, and 12105 are disposed at locations of the vehicle 12100, such as the front nose, side mirrors, rear bumper, trunk door, upper portion of the windshield in the cab, and the like. The camera unit 12101 disposed at the front nose and the camera unit 12105 disposed at the upper portion of the windshield in the cab mainly capture images in front of the vehicle 12100. The camera units 12102 and 12103 disposed at the side mirrors mainly capture images on the sides of the vehicle 12100. The camera unit 12104 disposed at the rear bumper or trunk door mainly captures images at the rear of the vehicle 12100. The front images captured by the camera units 12101 and 12105 are mainly used to detect, for example, front vehicles, pedestrians, obstacles, traffic lights, traffic signs, or lanes, and the like.

[0197] By the way, Fig. 20 An example of the imaging range of the imaging units 12101 to 12104 is shown. The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided at the front nose. The imaging ranges 12112 and 12113 respectively indicate the imaging ranges of the imaging units 12102 and 12103 provided at the side mirrors. The imaging range 12114 indicates the imaging range of the imaging unit 12104 provided at the rear bumper or the trunk door. For example, the image data taken by the imaging units 12101 to 12104 are superimposed to obtain a bird's-eye view image of the vehicle 12100 viewed from above.

[0198] At least one of the imaging units 12101 to 12104 may have a function capable of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging devices, or may be an imaging device having pixels for phase difference detection.

[0199] For example, the microcomputer 12051 obtains the distance to each solid object within the imaging range 12111 to 12114 and the change of the distance over time (relative speed relative to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, and thus the microcomputer can extract the following solid objects as the front vehicle: in particular, the closest solid object on the driving path of the vehicle 12100, and the solid object traveling at a predetermined speed (for example, 0 km / h or more) in the same direction as the vehicle 12100. In addition, the microcomputer 12051 can set the distance to the front vehicle that should be ensured in advance behind the front vehicle, and perform, for example, automatic braking control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, coordinated control for the purpose of, for example, autonomous driving that can travel autonomously without the need for driver operation can be achieved.

[0200] For example, the microcomputer 12051 can classify the three-dimensional object data related to the three-dimensional object into two-wheeled vehicles, ordinary cars, large vehicles, pedestrians, telephone poles, or other three-dimensional objects based on the distance information obtained from the camera units 12101 to 12104, thereby extracting the data and using the data to automatically avoid obstacles. For example, the microcomputer 12051 distinguishes the obstacles around the vehicle 12100 into obstacles that can be perceived by the driver of the vehicle 12100 and obstacles that are difficult for the driver to perceive. Then, the microcomputer 12051 determines the collision risk indicating the degree of danger of collision with each obstacle, and when the collision risk is equal to or greater than the set value, it is a situation where a collision is likely to occur, and at this time, a warning is issued to the driver through the audio speaker 12061 or the display unit 12062, or forced deceleration or steering for avoiding collision is performed through the drive system control unit 12010. Therefore, driving assistance that can avoid collisions can be provided.

[0201] At least one of the camera units 12101 to 12104 may be an infrared camera that detects infrared radiation. For example, the microcomputer 12051 may identify a pedestrian by determining whether there is a pedestrian in the image captured by the camera units 12101 to 12104. This identification of a pedestrian is obtained, for example, by the following process: a process for extracting feature points in the image captured by the camera units 12101 to 12104 as infrared cameras; and a process for performing pattern matching processing on a series of feature points representing the outline of an object and determining whether the object is a pedestrian. If the microcomputer 12051 determines that there is a pedestrian in the image captured by the camera units 12101 to 12104 and recognizes the pedestrian, the sound / image output unit 12052 controls the display unit 12062 to display a square outline for emphasis in a superimposed manner on the recognized pedestrian. In addition, the sound / image output unit 12052 may control the display unit 12062 to display, for example, an icon representing a pedestrian at a desired position.

[0202] So far, an example of a vehicle control system to which the technology related to the present disclosure can be applied has been described. The technology related to the present disclosure can be applied to, for example, the camera unit 12031 in the above-mentioned configuration.

[0203] Incidentally, embodiments of the present technology are not limited to the above-described embodiments, and various modifications may be made to the embodiments within a scope that does not depart from the spirit of the present technology.

[0204] This technology can also adopt the following constructions:

[0205] (1) Imaging devices, including:

[0206] a photoelectric conversion unit configured to perform photoelectric conversion;

[0207] A trench dug into a semiconductor substrate;

[0208] a negative fixed charge film composed of an oxide film, a nitrogen film, and an oxide film on a side wall of the trench; and

[0209] An electrode film is formed within the fixed charge film.

[0210] (2) The imaging device according to (1),

[0211] wherein the oxide film constituting the fixed charge film includes silicon monoxide (SiO), and

[0212] The nitrogen film constituting the fixed charge film includes silicon nitride (SiN).

[0213] (3) The imaging device according to (1) or (2),

[0214] Here, the nitrogen film constituting the fixed charge film includes a polysilicon film or a high dielectric constant film (high-k film).

[0215] (4) The imaging device according to any one of (1) to (3),

[0216] Among them, the nitrogen film used to constitute the fixed charge film includes a film using any one of the following materials: silicon nitride, zirconium, aluminum, tantalum, titanium, magnesium, yttrium, and lanthanide elements.

[0217] (5) The imaging device according to any one of (1) to (4), further comprising:

[0218] Wiring connected to a power source for applying voltage; and

[0219] A contact point connecting the wiring and the electrode film.

[0220] (6) The imaging device according to any one of (1) to (4), further comprising:

[0221] a light-shielding film formed on the light-receiving surface side of the photoelectric conversion unit; and

[0222] A contact connecting the light shielding film and the electrode film.

[0223] (7) The imaging device according to any one of (1) to (6),

[0224] Wherein, the groove does not penetrate the semiconductor substrate.

[0225] (8) The imaging device according to (5),

[0226] The contact points are formed corresponding to the pixels.

[0227] (9) The imaging device according to (5),

[0228] Wherein, the contact point is shared by a plurality of pixels.

[0229] (10) The imaging device according to any one of (1) to (9),

[0230] The groove is formed to surround the pixel and is formed in a partially disconnected state.

[0231] (11) An electronic device equipped with an imaging device, wherein the imaging device comprises:

[0232] a photoelectric conversion unit configured to perform photoelectric conversion;

[0233] A trench dug into a semiconductor substrate;

[0234] a negative fixed charge film composed of an oxide film, a nitrogen film, and an oxide film on a side wall of the trench; and

[0235] An electrode film is formed within the fixed charge film.

[0236] Reference numerals list

[0237] 10: Camera device

[0238] 11: Lens Group

[0239] 12: Camera devices

[0240] 13: DSP circuit

[0241] 14: Frame memory

[0242] 15: Display unit

[0243] 16: Recording unit

[0244] 17: Operating System

[0245] 18: Power System

[0246] 19: Bus

[0247] 20: CPU

[0248] 31: Pixels

[0249] 33: Vertical signal line

[0250] 41: Pixel array unit

[0251] 42: Vertical drive unit

[0252] 43: Column processing unit

[0253] 44: Horizontal drive unit

[0254] 45: System control unit

[0255] 46: Pixel drive line

[0256] 47: Vertical signal line

[0257] 48: Signal processing unit

[0258] 49: Data storage unit

[0259] 101: Incident Light

[0260] 110: Pixels

[0261] 111: Microlens

[0262] 113: Flattening film

[0263] 114: Light-shielding film

[0264] 115: Insulation film

[0265] 116: p-type semiconductor region

[0266] 117: Light receiving surface

[0267] 118: Semiconductor substrate

[0268] 120: n-type semiconductor region

[0269] 130: Pixel isolation unit

[0270] 131: Groove

[0271] 132: Fixed Charge Membrane

[0272] 133: Electrode membrane

[0273] 141: p-type semiconductor region

[0274] 150: Wiring layer

[0275] 151: Wiring

[0276] 152: Insulation layer

[0277] 161: Support substrate

[0278] 171: Contact

[0279] 190: Transfer transistor

[0280] 192: Reset transistor

[0281] 193: Amplifying transistor

[0282] 194: Select transistor

[0283] 201: SiO film

[0284] 202: SiN film

[0285] 203: SiO film

Claims

1. Camera devices, including: a photoelectric conversion unit configured to perform photoelectric conversion; A trench dug into a semiconductor substrate; a negative fixed charge film composed of a first oxide film, a nitrogen film, and a second oxide film on a sidewall of the trench; and an electrode film formed in the fixed charge film, the electrode film being in contact with the fixed charge film, wherein the nitrogen film is sandwiched between the first oxide film and the second oxide film, Furthermore, the first oxide film is disposed closest to the sidewall of the trench, and the second oxide film is disposed closest to the electrode film, wherein a thickness of the first oxide film is thinner than a thickness of the second oxide film.

2. The imaging device according to claim 1, in, The oxide film constituting the fixed charge film includes silicon monoxide (SiO), and the nitride film constituting the fixed charge film includes silicon nitride (SiN).

3. The imaging device according to claim 1, in, The nitrogen film constituting the fixed charge film includes a polysilicon film or a high dielectric constant film.

4. The imaging device according to claim 1, in, The nitrogen film used to constitute the fixed charge film includes a film using any one of the following materials: silicon nitride, hafnium, zirconium, aluminum, tantalum, titanium, magnesium, yttrium, and lanthanide elements.

5. The imaging device according to any one of claims 1 to 4, further comprising: Wiring connected to a power source for applying voltage; and A contact point connecting the wiring and the electrode film.

6. The imaging device according to any one of claims 1 to 4, further comprising: a light shielding film formed on a light receiving surface side of the photoelectric conversion unit; and A contact connecting the light shielding film and the electrode film.

7. The imaging device according to any one of claims 1 to 4, in, The trench does not penetrate the semiconductor substrate.

8. The imaging device according to claim 5, in, The contact points are formed corresponding to the respective pixels.

9. The imaging device according to claim 5, in, The contact point is shared by a plurality of pixels.

10. The imaging device according to any one of claims 1 to 4, in, The groove is formed to surround the pixel and is formed in a partially disconnected state.

11. Electronic equipment provided with the imaging device according to any one of claims 1 to 10.

Images