Image pickup element and image pickup device

Abstract

The purpose of the present invention is to maintain the linearity of an image signal with respect to a quantity of incident light. An imaging element has a pixel, a unit for connecting photoelectric conversion unit, a charge-holding unit, a plurality of charge transfer units, an image signal generation unit, and an on-chip lens. The pixel is provided with a plurality of photoelectric conversion units which are formed on a semiconductor substrate having a wiring region disposed on the front surface side thereof, and which generate an electric charge by performing photoelectric conversion of incident light from a subject. The unit for connecting photoelectric conversion units connects the plurality of photoelectric conversion units to each other. The charge-holding unit holds the generated electric charge. The plurality of charge transfer units are disposed for each of the plurality of photoelectric conversion units, and transfer the electric charge generated by the photoelectric conversion units to the charge-holding unit to be held. The image signal generation unit generates an image signal on the basis of the held electric charge. The on-chip lens is disposed on the pixel and condenses incident light to the plurality of photoelectric conversion units in common.

Description

[Technical Field]

[0001] The present disclosure relates to an imaging element and an imaging device. [Background technology]

[0002] An imaging element is used that includes pixels in which a common on-chip lens (microlens) is arranged across multiple photoelectric conversion units (see, for example, Patent Document 1). In this imaging element, the multiple photoelectric conversion units are divided into two, and image signals are generated based on each of the divided photoelectric conversion units, thereby making it possible to detect an image plane phase difference resulting from pupil division of an object image. This image plane phase difference makes it possible to detect the focal position of the object. Furthermore, this conventional technology can use an imaging mode that generates multiple image signals based on charges generated by each of the multiple photoelectric conversion units, and an imaging mode that generates a single image signal based on the sum of the charges of the multiple photoelectric conversion units.

[0003] Due to variations in the manufacturing process, a common on-chip lens may be positioned with misalignment for multiple photoelectric conversion units. In this case, differences occur in the amount of light incident on each of the multiple photoelectric conversion units, resulting in differences in sensitivity for each pixel. In a highly sensitive photoelectric conversion unit, the charge in the photoelectric conversion unit reaches a saturation charge amount in a relatively short time. Here, the saturation charge amount is the amount of charge that can be accumulated in the photoelectric conversion unit during an exposure period. When the charge in the photoelectric conversion unit reaches a saturation charge amount, the charge overflows from the photoelectric conversion unit. Normally, the charge overflowing from the photoelectric conversion unit is discharged outside the pixel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-052041 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-described conventional technology, in an imaging mode in which a single image signal is generated based on the sum of charges from multiple photoelectric conversion units, when one of the multiple photoelectric conversion units reaches a saturated charge amount, the charge generated by that photoelectric conversion unit is no longer reflected in the generation of subsequent image signals, resulting in a problem of reduced linearity of the image signal relative to the amount of incident light.

[0006] Therefore, the present disclosure proposes an image sensor and an image capturing apparatus that maintains the linearity of an image signal relative to the amount of incident light in an image sensor in which an on-chip lens is arranged in common for a plurality of photoelectric conversion units. [Means for solving the problem]

[0007] The imaging element of the present disclosure includes a pixel, a photoelectric conversion unit connection unit, a charge holding unit, multiple charge transfer units, an image signal generation unit, and an on-chip lens. The pixel includes multiple photoelectric conversion units formed on a semiconductor substrate having a wiring region disposed on its front surface, and configured to perform photoelectric conversion of incident light from a subject to generate charges. The photoelectric conversion unit connection unit connects the multiple photoelectric conversion units to each other. The charge holding unit holds the generated charges. The multiple charge transfer units are disposed for each of the multiple photoelectric conversion units, and transfer the charges generated by the photoelectric conversion units to the charge holding unit for storage. The image signal generation unit generates an image signal based on the stored charges. The on-chip lens is disposed in the pixel and collects the incident light in common to the multiple photoelectric conversion units. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an imaging device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a pixel according to an embodiment of the present disclosure. [Figure 3] 1 is a plan view showing a configuration example of a pixel according to a first embodiment of the present disclosure. [Figure 4] 1 is a cross-sectional view showing a configuration example of a pixel according to a first embodiment of the present disclosure. [Figure 5]FIG. 2 is a plan view showing an example of pixel arrangement according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a plan view illustrating an example of generation of an image signal according to an embodiment of the present disclosure. [Figure 7] FIG. 10 is a plan view showing a configuration example of a pixel according to a second embodiment of the present disclosure. [Figure 8] FIG. 10 is a plan view showing a configuration example of a pixel according to a third embodiment of the present disclosure. [Figure 9] FIG. 10 is a plan view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. [Figure 10] FIG. 10 is a plan view showing another configuration example of a pixel according to the fourth embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. [Figure 12] FIG. 13 is a cross-sectional view showing an example of the configuration of a pixel according to a sixth embodiment of the present disclosure. [Figure 13A] FIG. 13 is a plan view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. [Figure 13B] FIG. 13 is a plan view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. [Figure 13C] FIG. 13 is a plan view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. [Figure 13D] FIG. 13 is a plan view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. [Figure 14] FIG. 13 is a cross-sectional view showing an example of the configuration of a pixel according to a seventh embodiment of the present disclosure. [Figure 15] FIG. 1 is a block diagram showing an example of the configuration of an imaging device mounted on an electronic device. [Figure 16] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 17] FIG. 2 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit. [Figure 18] FIG. 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 19] FIG. 2 is a block diagram showing an example of the functional configuration of a camera head and a CCU. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. In the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Fourth Embodiment 5. Fifth Embodiment 6. Sixth Embodiment 7. Seventh Embodiment 8. Example of imaging device configuration 9. Mobile Application Examples 10. Application example to endoscopic surgery system

[0010] (1. First embodiment) [Configuration of imaging device] FIG. 1 is a diagram illustrating an example configuration of an imaging device according to an embodiment of the present disclosure. As shown in FIG. 1, the imaging element 1 of this example includes a pixel region (so-called imaging region) 3 in which pixels 100, each including a plurality of photoelectric conversion elements, are regularly arranged two-dimensionally on a semiconductor substrate 11, e.g., a silicon substrate, and a peripheral circuit section. Each pixel 100 includes a photoelectric conversion element, e.g., a photodiode, and a plurality of pixel transistors (so-called MOS transistors). The plurality of pixel transistors may be configured with, for example, three transistors: a transfer transistor (a charge transfer section, described below), a reset transistor, and an amplification transistor. Alternatively, a selection transistor may be added to the pixel 100 to form a four-transistor configuration. The pixel 100 may also have a shared pixel structure. This pixel-sharing structure includes a plurality of photodiodes, a plurality of transfer transistors, a shared floating diffusion region, and a shared pixel transistor.

[0011] The peripheral circuit section includes a vertical drive circuit 4, a column signal processing circuit 5, a horizontal drive circuit 6, an output circuit 7, a control circuit 8, and the like.

[0012] The control circuit 8 receives an input clock and data instructing the operation mode, etc., and outputs data such as internal information of the imaging device. That is, the control circuit 8 generates clock signals and control signals that serve as the basis for the operation of the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. These signals are then input to the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc.

[0013] The vertical drive circuit 4 is configured with, for example, a shift register, selects pixel drive wirings 13, supplies pulses for driving pixels to the selected pixel drive wirings, and drives the pixels row by row. That is, the vertical drive circuit 4 selects and scans each pixel 100 in the pixel region 3 row by row in the vertical direction, and supplies pixel signals based on signal charges generated in accordance with the amount of light received in, for example, photodiodes serving as photoelectric conversion elements in each pixel 100 to the column signal processing circuit 5 via vertical signal lines 9.

[0014] The column signal processing circuits 5 are arranged, for example, for each column of the pixels 100, and perform signal processing such as noise removal on signals output from one row of the pixels 100 for each pixel column. That is, the column signal processing circuits 5 perform signal processing such as CDS (Correlated Double Sampling) for removing fixed pattern noise specific to the pixels 100, signal amplification, AD conversion, etc. A horizontal selection switch (not shown) is provided at the output stage of the column signal processing circuit 5 and connected between the output stage and the horizontal signal line 10.

[0015] The horizontal drive circuit 6 is configured, for example, by a shift register, and sequentially outputs horizontal scanning pulses to select each of the column signal processing circuits 5 in turn, causing each of the column signal processing circuits 5 to output a pixel signal to the horizontal signal line 10.

[0016] The output circuit 7 processes and outputs signals sequentially supplied from each of the column signal processing circuits 5 via the horizontal signal line 10. For example, the output circuit 7 may perform only buffering, or may perform black level adjustment, column variation correction, various digital signal processing, etc. The input / output terminal 12 exchanges signals with the outside.

[0017] [Pixel configuration] 2 is a diagram showing an example configuration of a pixel according to an embodiment of the present disclosure. The figure is a circuit diagram showing an example configuration of a pixel 100. The pixel 100 in the figure includes photoelectric conversion units 101-104, charge transfer units 105-108, a charge storage unit 109, a photoelectric conversion unit connection unit 110, and an image signal generation unit 120. The photoelectric conversion unit connection unit 110 is configured with MOS transistors 111-114. The image signal generation unit 120 includes a reset transistor 121, an amplification transistor 122, and a selection transistor 123. The photoelectric conversion units 101-104 can be configured with photodiodes.

[0018] The MOS transistors 111-114, the charge transfer units 105-108, the reset transistor 121, the amplifier transistor 122, and the select transistor 123 can be configured using n-channel MOS transistors. In this n-channel MOS transistor, the drain-source can be made conductive by applying a voltage exceeding the threshold of the gate-source voltage Vgs to the gate. Hereinafter, this voltage exceeding the threshold of the gate-source voltage Vgs will be referred to as an ON voltage. Furthermore, a control signal including this ON voltage will be referred to as an ON signal. The control signal is transmitted via a signal line TG1 or the like.

[0019] As described above, pixel drive wiring 13 and vertical signal lines 9 are wired to the pixel 100. The pixel drive wiring 13 in the figure includes signal lines SC, TG1, TG2, TG3, TG4, RST, and SEL. The vertical signal lines 9 include signal line VO. In addition, a power supply line Vdd is wired to the pixel 100. This power supply line Vdd is a wiring that supplies power to the pixel 100.

[0020] The anode of the photoelectric conversion unit 101 is grounded, and the cathode is connected to the source of the charge transfer unit 105. The anode of the photoelectric conversion unit 102 is grounded, and the cathode is connected to the source of the charge transfer unit 106. The anode of the photoelectric conversion unit 103 is grounded, and the cathode is connected to the source of the charge transfer unit 107. The anode of the photoelectric conversion unit 104 is grounded, and the cathode is connected to the source of the charge transfer unit 108. The drain of the charge transfer unit 105 is connected to the drain of the charge transfer unit 106, the drain of the charge transfer unit 107, the drain of the charge transfer unit 108, the source of the reset transistor 121, the gate of the amplification transistor 122, and one end of the charge holding unit 109. The other end of the charge holding unit 109 is grounded. The drain of the reset transistor 121 and the drain of the amplification transistor 122 are connected to the power supply line Vdd. The source of the amplification transistor 122 is connected to the drain of the selection transistor 123, and the source of the selection transistor 123 is connected to the signal line VO.

[0021] The gate of charge transfer unit 105 is connected to signal line TG1, and the gate of charge transfer unit 106 is connected to signal line TG2. The gate of charge transfer unit 107 is connected to signal line TG3, and the gate of charge transfer unit 108 is connected to signal line TG4. The gate of reset transistor 121 is connected to signal line RST, and the gate of selection transistor 123 is connected to signal line SEL.

[0022] The cathode of the photoelectric conversion unit 101 is further connected to the source of the MOS transistor 111. The cathode of the photoelectric conversion unit 102 is further connected to the source of the MOS transistor 112. The cathode of the photoelectric conversion unit 103 is further connected to the source of the MOS transistor 113. The cathode of the photoelectric conversion unit 104 is further connected to the source of the MOS transistor 114. The drains of the MOS transistors 111, 112, 113, and 114 are connected to one another. The gates of the MOS transistors 111, 112, 113, and 114 are commonly connected to a signal line SC. For convenience, the drains and sources of the MOS transistors 111-114 are described separately, but the MOS transistors 111-114 can transfer charges in both directions without distinguishing between the drains and sources.

[0023] The photoelectric conversion units 101-104 perform photoelectric conversion of incident light. These photoelectric conversion units 101-104 can be configured with photodiodes formed on a semiconductor substrate 130, which will be described later. The photoelectric conversion units 101-104 perform photoelectric conversion of incident light during an exposure period and store charges generated by the photoelectric conversion.

[0024] The charge holding section 109 holds the charges generated by the photoelectric conversion sections 101 to 104. The charge holding section 109 can be configured by a floating diffusion region (FD), which is a semiconductor region formed in the semiconductor substrate .

[0025] The charge transfer units 105-108 transfer charges. The charge transfer unit 105 transfers charges generated by photoelectric conversion in the photoelectric conversion unit 101 to the charge holding unit 109, and the charge transfer unit 106 transfers charges generated by photoelectric conversion in the photoelectric conversion unit 102 to the charge holding unit 109. The charge transfer unit 107 transfers charges generated by photoelectric conversion in the photoelectric conversion unit 103 to the charge holding unit 109, and the charge transfer unit 108 transfers charges generated by photoelectric conversion in the photoelectric conversion unit 104 to the charge holding unit 109. The charge transfer units 105, etc. transfer charges by establishing electrical continuity between the photoelectric conversion units 101, etc. and the charge holding unit 109, respectively. Control signals for the charge transfer units 105-108 are transmitted by signal lines TG1-TG4, respectively.

[0026] The image signal generation unit 120 generates an image signal based on the charges held in the charge holding unit 109. As described above, the image signal generation unit 120 is configured by the reset transistor 121, the amplification transistor 122, and the selection transistor 123.

[0027] The reset transistor 121 resets the charge holding unit 109. This reset can be performed by establishing electrical continuity between the charge holding unit 109 and a power supply line Vdd to drain the charge from the charge holding unit 109. A control signal for the reset transistor 121 is transmitted via a signal line RST.

[0028] The amplification transistor 122 amplifies the voltage of the charge holding unit 109. The gate of the amplification transistor 122 is connected to the charge holding unit 109. Therefore, an image signal having a voltage corresponding to the charge held in the charge holding unit 109 is generated at the source of the amplification transistor 122. Furthermore, by making the selection transistor 123 conductive, this image signal can be output to a signal line VO. A control signal for the selection transistor 123 is transmitted by a signal line SEL.

[0029] During the exposure period, the photoelectric conversion units 101-104 perform photoelectric conversion of incident light to generate and store electric charges. After the exposure period has elapsed, the electric charges of the photoelectric conversion units 101-104 are transferred by the charge transfer units 105-108 to the charge holding unit 109, where they are held. An image signal is generated by the image signal generation unit 120 based on the held electric charges.

[0030] The charge transfer units 105-108 can perform collective transfer, in which they commonly transfer the charges generated by the photoelectric conversion units 101-104 to the charge holding unit 109 and cause the charge holding unit 109 to simultaneously hold the charges generated by the photoelectric conversion units 101-104. In this case, the image signal generation unit 120 generates an image signal based on the charges obtained by adding up the charges generated by the photoelectric conversion units 101-104. The charge transfer units 105-108 also perform individual transfer, in which they individually transfer the charges generated by the photoelectric conversion units 101-104 to the charge holding unit 109. In this case, the image signal generation unit 120 generates an image signal each time the charges of the photoelectric conversion units 101-104 are transferred to the charge holding unit 109. This generates four image signals corresponding to the photoelectric conversion units 101-104, respectively.

[0031] The photoelectric conversion unit connection unit 110 connects the photoelectric conversion units 101-104 to each other. As described below, the photoelectric conversion unit connection unit 110 can be configured with a single element. For convenience, the operation of the photoelectric conversion unit connection unit 110 will be described using the circuit of the MOS transistors 111-114. When an on-voltage is applied to the gates of the MOS transistors 111-114 from the signal line SC, the MOS transistors 111-114 become conductive. This connects the cathodes of the photoelectric conversion units 101-104 to each other. This causes the charges accumulated in the photoelectric conversion units 101-104 to be evenly distributed to the photoelectric conversion units 101-104. Even if the amounts of charge generated by photoelectric conversion in the photoelectric conversion units 101-104 are different from one another, the amounts of charge held by the photoelectric conversion units 101-104 can be made equal.

[0032] The photoelectric conversion units 101-104 are preferably connected to one another by the photoelectric conversion unit connection unit 110 when charges to be collectively transferred by the charge transfer units 105-108 are generated. This is because even if the photoelectric conversion units 101-104 have different sensitivities and the accumulated charges in some of the photoelectric conversion units 101-104 reach the saturated charge amount, charge overflow can be prevented.

[0033] [Plane configuration of pixels] FIG. 3 is a plan view showing an example of the configuration of a pixel according to the first embodiment of the present disclosure. This figure is a plan view showing an example of the configuration of a pixel 100. In the pixel 100 shown in FIG. 3, photoelectric conversion units 101-104 are arranged in two rows and two columns. As will be described later, the photoelectric conversion units 101-104 in FIG. 3 represent semiconductor regions formed on a semiconductor substrate 130. Charge transfer units 105-108 are arranged at positions overlapping the photoelectric conversion units 101-104, respectively. As will be described later, the charge transfer units 105-108 in FIG. 3 represent gate electrodes of respective MOS transistors. A charge retention unit 109 is arranged adjacent to the charge transfer units 105-108. In the pixel 100 shown in FIG. 3, charge retention units 109a and 109b are arranged. The charge retention unit 109a is arranged between the charge transfer units 105 and 106, and the charge retention unit 109b is arranged between the charge transfer units 107 and 108. The charge holding units 109a and 109b are connected to each other by a wiring 163, which will be described later. The wiring 163 connects the charge holding units 109a and 109b to the image signal generating unit 120.

[0034] Furthermore, a photoelectric conversion unit connection section 110 is disposed in the center of the pixel 100. This photoelectric conversion unit connection section 110 is configured in a shape adjacent to each of the photoelectric conversion units 101-104. As will be described later, the photoelectric conversion unit connection section 110 in the same figure represents a gate electrode. A wiring 162 is connected to the gate electrode of the photoelectric conversion unit connection section 110. This wiring 162 is a wiring corresponding to the signal line SC described in FIG. 2. Furthermore, an image signal generation section 120 is disposed above and below the pixel 100, divided into two sections. A circuit including an amplification transistor 122 and a selection transistor 123 is disposed in the image signal generation section 120 on the upper side of the pixel 100, and a circuit including a reset transistor 121 is disposed in the image signal generation section 120 on the lower side of the pixel 100.

[0035] A pixel separator 171, which will be described later, is disposed at the boundary of the pixel 100. Furthermore, an intra-pixel separator 172, which will be described later, is disposed between the photoelectric conversion units 101-104 within the pixel 100.

[0036] [Cross-sectional structure of pixel] 4 is a cross-sectional view showing an example of the configuration of a pixel according to the first embodiment of the present disclosure. This figure is a cross-sectional view showing an example of the configuration of a pixel 100, taken along line a-a' in FIG. 3. The pixel 100 in this figure includes a semiconductor substrate 130, an insulating film 159, a wiring region 160, a pixel separator 171, an intra-pixel separator 172, an insulating film 191, a color filter 192, a light-shielding film 193, and an on-chip lens 194. This figure also shows an image signal generator 120.

[0037] The semiconductor substrate 130 is a semiconductor substrate on which diffusion layers of elements of the pixel 100 are disposed. This semiconductor substrate 130 can be made of, for example, silicon (Si). Elements such as the photoelectric conversion unit 101 can be disposed in a well region formed in the semiconductor substrate 130. For convenience, the semiconductor substrate 130 in the figure is assumed to be configured in a p-type well region. Diffusion layers of elements can be formed by disposing n-type or p-type semiconductor regions in this well region. The figure also shows photoelectric conversion units 101 and 104, charge transfer units 105 and 108, charge retention units 109a and 109b, and a photoelectric conversion unit connection unit 110.

[0038] The photoelectric conversion unit 101 is composed of an n-type semiconductor region 141. Specifically, a photodiode formed by a pn junction at the interface between the n-type semiconductor region 141 and a surrounding p-type well region corresponds to the photoelectric conversion unit 101. Similarly, the photoelectric conversion unit 104 is composed of an n-type semiconductor region 142. Charges generated by photoelectric conversion in the photoelectric conversion units 101 and 104 during an exposure period are accumulated in the n-type semiconductor regions 141 and 142. Furthermore, n-type semiconductor regions 143 and 144 that constitute the charge retention units 109a and 109b are arranged on the surface side of the semiconductor substrate 130.

[0039] An intra-pixel isolation portion 172 is disposed between the photoelectric conversion portions 101 and 104. This intra-pixel isolation portion 172 electrically isolates the n-type semiconductor regions 141 and 142 that constitute the photoelectric conversion portions 101 and 104. The intra-pixel isolation portion 172 can be formed, for example, by an insulating member embedded in a groove portion 178 formed in the semiconductor substrate 130. Silicon oxide (SiO2) can be used for this insulating member. The groove portion 178 is formed from the back surface side of the semiconductor substrate 130 and is deep enough that its bottom reaches near the front surface side of the semiconductor substrate 130.

[0040] Furthermore, pixel separators 171 are disposed at the boundaries between the pixels 100 of the semiconductor substrate 130. These pixel separators 171 electrically separate adjacent pixels 100 from each other. The pixel separators 171 can be formed, for example, by an insulating material embedded in grooves 179 formed in the semiconductor substrate 130. SiO2 can be used for this insulating material. Similar to the grooves 178, the grooves 179 are formed from the back surface side of the semiconductor substrate 130 and are configured to a depth such that their bottoms reach near the front surface side of the semiconductor substrate 130.

[0041] The insulating film 159 is a film that insulates the front surface side of the semiconductor substrate 130. This insulating film 159 can be made of SiO2 or silicon nitride (SiN).

[0042] Gate electrodes 151 and 152 are disposed on the surface side of the semiconductor substrate 130. The gate electrodes 151 and 152 constitute the gates of the charge transfer units 105 and 108, respectively. These gate electrodes 151 and 152 are configured to be partially embedded in the semiconductor substrate 130. The gate electrode 151 is configured to be shaped so that its bottom is adjacent to the n-type semiconductor region 141 that constitutes the photoelectric conversion unit 101 and its side is adjacent to the n-type semiconductor region 143 that constitutes the charge retention unit 109a. When an on-voltage is applied to the gate electrode 151, a channel is formed in the semiconductor substrate 130 near the gate electrode 151. This channel establishes electrical continuity between the photoelectric conversion unit 101 and the charge retention unit 109a, allowing charge transfer. In this manner, the charge transfer unit 105 transfers charge in the thickness direction of the semiconductor substrate 130.

[0043] Like the gate electrode 151, the gate electrode 152 is also configured to be partially embedded in the semiconductor substrate 130. The gate electrodes 151 and 152 can be configured from polycrystalline silicon. Note that an insulating film 159 between the gate electrodes 151 and 152 and the semiconductor substrate 130 configures a gate insulating film. The charge holding units 109a and 109b are commonly connected to the input of the image signal generation unit 120.

[0044] The wiring region 160 is disposed on the surface side of the semiconductor substrate 130, and is a region where wiring for the pixel 100 is disposed. The wiring region 160 includes wiring 162 and an insulating layer 161. The wiring 162 transmits signals and the like for the elements of the pixel 100. The wiring 162 can be made of a conductor such as copper (Cu) or tungsten (W). The insulating layer 161 insulates the wiring 162 and the like. The insulating layer 161 can be made of, for example, SiO2. The wiring 162 in the figure represents wiring connected to a gate electrode 153, which will be described later. The wiring 162 and the gate electrode 153 can be connected by a contact plug 169.

[0045] The insulating film 191 insulates the back surface side of the semiconductor substrate 130. This insulating film 191 can be made of, for example, SiO2.

[0046] The color filter 192 is an optical filter that transmits light of a predetermined wavelength out of the incident light. For the color filter 192, for example, a color filter that transmits red light, green light, and blue light can be used.

[0047] The light-shielding film 193 is disposed at the boundary between the pixels 100 to block incident light. This light-shielding film 193 can be made of tungsten. By disposing the light-shielding film 193, it is possible to block light that is incident obliquely from the adjacent pixel 100.

[0048] The on-chip lens 194 is a lens that condenses incident light. The on-chip lens 194 is configured in a hemispherical shape and condenses incident light onto the photoelectric conversion units 101 and 102.

[0049] The image sensor 1 in the figure is a back-illuminated image sensor in which incident light is irradiated onto the photoelectric conversion unit 101 and the like from the back side of the semiconductor substrate 130.

[0050] The photoelectric conversion unit connection unit 110 is composed of a semiconductor region 145 and a gate electrode 153. The semiconductor region 145 is disposed near the surface side of the semiconductor substrate 130 at the center of the pixel 100. This semiconductor region 145 is adjacent to the semiconductor regions 141 and 142 that constitute the photoelectric conversion units 101 and 104, respectively. The semiconductor region 145 is configured to have a different conductivity type from the semiconductor regions 141 and 142. The semiconductor region 145 in the same figure can be configured to be p-type. The gate electrode 153 is configured to be partially embedded in the semiconductor substrate 130, with its bottom and sides adjacent to the semiconductor region 145. The gate electrode 153 can be formed by forming an opening 158 on the surface side of the semiconductor substrate 130 and disposing polycrystalline silicon in this opening 158. An insulating film 159 that constitutes a gate insulating film is also disposed between the gate electrode 153 and the semiconductor substrate 130.

[0051] When an on-voltage is applied to the gate electrode 153, a channel is formed in the semiconductor region 145. This channel establishes electrical continuity between the semiconductor regions 141 and 142 that constitute the photoelectric conversion units 101 and 104. This allows charges to move between the semiconductor regions 141 and 142. If the amount of charge stored in the semiconductor regions 141 and 142 differs, a charge concentration gradient is formed. Charges diffuse in accordance with this concentration gradient, and the charges move from the semiconductor region with more accumulated charge to the other semiconductor region. This allows the charges stored in the photoelectric conversion units 101-104 to be evenly distributed to the photoelectric conversion units 101-104.

[0052] Furthermore, by configuring the gate electrode 153 to be embedded in the semiconductor substrate 130, the area of ​​the semiconductor region 145 that constitutes the photoelectric conversion unit connection portion 110 can be expanded in the thickness direction of the semiconductor substrate 130. The area in which the channel is formed can be expanded while preventing an increase in the area of ​​the photoelectric conversion unit connection portion 110 in the surface direction of the semiconductor substrate 130.

[0053] Furthermore, since charges can also be accumulated in the semiconductor region 145 that constitutes the photoelectric conversion unit connection section 110, the amount of saturated charges during bulk transfer can be increased.

[0054] [Pixel arrangement] FIG. 5 is a plan view showing an example of a pixel arrangement according to an embodiment of the present disclosure. This figure is a plan view showing an example of an arrangement of pixels 100. The rectangles inside the pixels 100 in this figure represent photoelectric conversion units 101-104. The circles inside the pixels 100 represent on-chip lenses. Furthermore, "R," "G," and "B" in this figure represent the types of color filters 192 arranged in the pixels 100. "R," "G," and "B" represent color filters 192 that transmit red light, green light, and blue light, respectively. This figure shows an example in which two rows and two columns of pixels 100 are arranged in a Bayer array. The pixel region 3 is formed by repeatedly arranging the pixels 100 arranged in two rows and two columns as shown in this figure. Note that the image signal generation unit 120 is omitted from this figure.

[0055] When an image signal is generated for each of the photoelectric conversion units 101-104, individual charge transfer is performed. On the other hand, when a single image signal is generated by adding up the charges generated by the photoelectric conversion units 101-104, collective charge transfer is performed for the photoelectric conversion units 101-104. Consider a case where the on-chip lens 194 in the figure is positioned offset from the center of the pixel 100 (the intersection of the dotted lines in the figure). Specifically, if the on-chip lens 194 is positioned offset to the right in the figure, the amount of incident light on the photoelectric conversion units 103 and 104 increases, while the amount of incident light on the photoelectric conversion units 101 and 102 decreases. As a result of the increase in the amount of charge in the photoelectric conversion units 103 and 104, the photoelectric conversion units 103 and 104 reach their saturated charge amounts earlier. In this case, by conducting the photoelectric conversion unit connection unit 110, the charges in the photoelectric conversion units 103 and 104 can be transferred to the photoelectric conversion units 101 and 102. It is possible to prevent the charges from overflowing from the photoelectric conversion units 103 and 104, and maintain the linearity of the image signal.

[0056] It is also possible to divide the photoelectric conversion units 101-104 into two groups and generate an image signal for each group. For example, the photoelectric conversion units 101-104 can be divided horizontally in the figure to form a group of photoelectric conversion units 101 and 102 and a group of photoelectric conversion units 103 and 104. In this case, an image signal is generated by adding up the charges generated by the photoelectric conversion units 101 and 102, and an image signal is generated by adding up the charges generated by the photoelectric conversion units 103 and 104. Each image signal generated by dividing the photoelectric conversion unit of the pixel 100 into two regions (groups) in this way is called a phase difference signal. This phase difference signal can be used to detect the image plane phase difference of the subject image.

[0057] An optical system, such as an imaging lens, is disposed on the subject side of the image sensor 1. Photoelectric conversion units 101 and 102 are irradiated with light that has passed through the right side of the imaging lens, and photoelectric conversion units 103 and 104 are irradiated with light that has passed through the left side of the imaging lens. This method of dividing the photoelectric conversion unit of pixel 100 into two regions and generating respective image signals is called pupil division. The focal position of the imaging lens can be detected by detecting the shift in the images generated for each divided phase difference signal. Autofocus can be performed by moving the imaging lens in the optical axis direction based on the detected focal position. Pupil division can also be performed by dividing the photoelectric conversion units 101-104 vertically in the same figure.

[0058] [Image signal generation] FIG. 6 is a plan view showing an example of image signal generation according to an embodiment of the present disclosure. This figure is a timing diagram illustrating an example of image signal generation. In this figure, "RST," "SEL," "TG1," "TG2," "TG3," "TG4," and "SC" represent control signals transmitted via signal lines RST, SEL, TG1, TG2, TG3, TG4, and SC, respectively. The "1" value of these binarized control signals represents the aforementioned on-voltage signal. The dashed line in this figure represents a 0V level. "VO" in this figure represents the image signal of signal line VO. The control signal in this figure represents an example of a control signal that applies a voltage of 0V to turn off the MOS transistor to be controlled. A different voltage, for example, -1V, can also be applied as the signal voltage that turns off this MOS transistor.

[0059] In the initial state, a value of "0" is applied to signal lines RST, SEL, TG1, TG2, TG3, TG4, and SC. The first half of the figure (T1 to T11) represents the generation of image signals by individual transfer, and the second half of the figure (T12 to T18) represents the generation of image signals by collective transfer.

[0060] At T1, an ON signal is applied to signal lines RST, TG1, TG2, TG3, and TG4, which turns on the reset transistor 121 and charge transfer units 105-108, resetting the photoelectric conversion units 101-104 and charge holding unit 109.

[0061] At T2, the application of the ON signals to the signal lines RST, TG1, TG2, TG3, and TG4 is stopped, thereby starting the exposure period and accumulating charges generated by photoelectric conversion in the photoelectric conversion units 101-104.

[0062] At T3, an ON signal is applied to the signal line SEL. The application of the ON signal to the signal line SEL continues until an image signal based on the charges of the photoelectric conversion units 101-104 is output.

[0063] At T4, an ON signal is applied to the signal line RST to reset the charge holding unit 109. At T4, the exposure period ends.

[0064] At T5, the application of the ON signal to the signal line RST is stopped.

[0065] At T6, an ON signal is applied to the signal line TG1, the charge transfer unit 105 becomes conductive, and the charge accumulated in the photoelectric conversion unit 101 is transferred to the charge holding unit 109.

[0066] At T7, the application of the ON signal to the signal line TG1 is stopped. During the next period until T8, an image signal a corresponding to the charge of the photoelectric conversion unit 101 is output from the signal line VO.

[0067] At T8, an ON signal is applied to the signal line RST, and the charge holding unit 109 is reset.

[0068] At T9, the application of the ON signal to the signal line RST is stopped.

[0069] At T10, an ON signal is applied to the signal line TG2, the charge transfer unit 106 becomes conductive, and the charge accumulated in the photoelectric conversion unit 102 is transferred to the charge holding unit 109.

[0070] At T11, the application of the ON signal to the signal line TG2 is stopped, after which an image signal b corresponding to the charge of the photoelectric conversion unit 102 is output from the signal line VO.

[0071] Thereafter, the charge holding unit 109 is repeatedly reset and individually transferred, and image signals based on the charges accumulated in the photoelectric conversion units 103 and 104 are sequentially generated.

[0072] In this way, an image signal can be generated by individual transfer. Next, a mode in which an image signal is generated by collective transfer of electric charges will be described.

[0073] At T12, an ON signal is applied to signal lines RST, TG1, TG2, TG3, and TG4, which turns on the reset transistor 121 and charge transfer units 105-108, resetting the photoelectric conversion units 101-104 and charge holding unit 109.

[0074] At T13, the application of the ON signals to the signal lines RST, TG1, TG2, TG3, and TG4 is stopped, thereby starting the exposure period and accumulating charges generated by photoelectric conversion in the photoelectric conversion units 101 and 102.

[0075] At T14, an ON signal is applied to the signal line SEL. The application of the ON signal to the signal line SEL continues until the pixel 100 outputs an image signal.

[0076] At T15, an ON signal is applied to the signal line RST to reset the charge holding unit 109. At T15, the exposure period ends.

[0077] At T16, the application of the ON signal to the signal line RST is stopped.

[0078] At T17, an ON signal is applied to the signal lines TG1, TG2, TG3, and TG4, causing the charge transfer units 105-108 to become conductive, and the charges accumulated in the photoelectric conversion units 101-104 to be transferred to the charge holding unit 109 (collective transfer).

[0079] At T18, the application of the ON signals to the signal lines TG1, TG2, TG3, and TG4 is stopped, and then the image signal c corresponding to the charge in the charge holding unit 109 is output from the signal line VO.

[0080] As described above, the image sensor 1 according to the first embodiment of the present disclosure includes a photoelectric conversion unit connection unit 110 in each pixel 100, which connects the photoelectric conversion units 101-104 to each other. This prevents charge overflow even when some of the photoelectric conversion units 101-104 reach a saturated charge amount, and maintains the linearity of the image signal relative to the amount of incident light.

[0081] (2. Second Embodiment) The image sensor 1 of the first embodiment described above includes an image signal generation unit 120 for each pixel 100. In contrast, the image sensor 1 of the second embodiment of the present disclosure differs from the first embodiment described above in that it includes a plurality of image signal generation units 120 for each pixel 100.

[0082] [Plane configuration of pixels] 7 is a plan view showing a configuration example of a pixel according to a second embodiment of the present disclosure. Similar to FIG. 3, this figure is a plan view showing a configuration example of a pixel 100. The pixel 100 in this figure differs from the pixel 100 in FIG. 3 in that it includes two image signal generation units 120.

[0083] The pixel 100 in the figure includes image signal generation units 120a and 120b. The image signal generation unit 120a includes a reset transistor 121a, an amplifier transistor 122a, and a selection transistor 123a, and is located adjacent to the lower left of the pixel 100 in the figure. The image signal generation unit 120a is connected to the charge holding unit 109a via a wiring 163a. ​​The image signal generation unit 120b includes a reset transistor 121b, an amplifier transistor 122b, and a selection transistor 123b, and is located adjacent to the upper right of the pixel 100 in the figure. The image signal generation unit 120b is connected to the charge holding unit 109b via a wiring 163b.

[0084] Since the image signal generation units 120a and 120b are arranged in the charge holding units 109a and 109b, respectively, image signals can be simultaneously generated based on the charges held in the charge holding units 109a and 109b. When generating image signals by individual transfer or when generating phase difference signals by dividing the signals between the photoelectric conversion units 101 and 102 and the photoelectric conversion units 103 and 104, the time required for signal generation can be shortened.

[0085] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0086] In this way, the imaging device 1 according to the second embodiment of the present disclosure includes a plurality of image signal generating sections 120. This makes it possible to reduce the time required to generate image signals and the like.

[0087] (3. Third Embodiment) In the image sensor 1 of the first embodiment described above, the image signal generation unit 120 is arranged separately above and below the pixel 100. In contrast, the image sensor 1 of the third embodiment of the present disclosure differs from the first embodiment described above in that the image signal generation unit 120 is arranged along two adjacent sides of the pixel 100.

[0088] [Plane configuration of pixels] 8 is a plan view showing a configuration example of a pixel according to the third embodiment of the present disclosure. Similar to FIG. 3, this figure is a plan view showing a configuration example of a pixel 100. The pixel 100 in this figure is configured such that an image signal generating unit 120 generates a pixel signal corresponding to the pixel 100. Next to It differs from the pixel 100 in FIG. 3 in that it is arranged along two adjacent sides.

[0089] The image signal generation unit 120 in the figure is disposed adjacent to the top surface and right surface of the pixel 100 in the figure. This allows the length of the wiring 163 connecting to the charge retention unit 109 to be shortened. For example, in the pixel 100 in the figure, the length of the wiring 163 connecting the charge retention unit 109b and the reset transistor 121 is shortened. Because the length of the wiring 163 is shortened, the parasitic capacitance of the wiring 163 can be reduced. This makes it possible to prevent a decrease in sensitivity.

[0090] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0091] As described above, in the image sensor 1 according to the third embodiment of the present disclosure, the image signal generation unit 120 is arranged in one location, which makes it possible to shorten the length of the wiring 163 connecting to the charge holding unit 109. This makes it possible to prevent a decrease in sensitivity when generating an image signal.

[0092] (4. Fourth Embodiment) In the image sensor 1 of the first embodiment described above, the photoelectric conversion unit connection unit 110 is disposed at the center of the pixel 100. In contrast, the image sensor 1 of the fourth embodiment of the present disclosure differs from the first embodiment described above in that the charge holding unit 109 is disposed at the center of the pixel 100.

[0093] [Plane configuration of pixels] 9 is a plan view showing an example of the configuration of a pixel according to a fourth embodiment of the present disclosure. Similar to FIG. 3, this figure is a plan view showing an example of the configuration of a pixel 100. The pixel 100 in this figure differs from the pixel 100 in FIG. 3 in that the charge storage section 109 is disposed in the center of the pixel 100, and the photoelectric conversion section connection sections 110, which are divided into four, are disposed between the photoelectric conversion sections.

[0094] In the pixel 100 shown in the figure, a single charge storage unit 109 is disposed in the center of the pixel 100. Charge transfer units 105-108 are disposed adjacent to this charge storage unit 109. A wiring 163 is connected to the charge storage unit 109. Because this wiring 163 is wired to the single charge storage unit 109, the length of the wiring 163 can be shortened.

[0095] The pixel 100 in the figure also includes photoelectric conversion unit connections 110a, 110b, 110c, and 110d. The photoelectric conversion unit connection 110a is disposed between the photoelectric conversion units 101 and 103 and connects the photoelectric conversion units 101 and 103. The photoelectric conversion unit connection 110b is disposed between the photoelectric conversion units 103 and 104 and connects the photoelectric conversion units 103 and 104. The photoelectric conversion unit connection 110c is disposed between the photoelectric conversion units 104 and 102 and connects the photoelectric conversion units 104 and 102. The photoelectric conversion unit connection 110d is disposed between the photoelectric conversion units 102 and 101 and connects the photoelectric conversion units 102 and 101.

[0096] The photoelectric conversion unit connectors 110a, 110b, 110c, and 110d each include a gate electrode 153 (shown). By applying an on signal to these gate electrodes 153 to turn on the photoelectric conversion unit connectors 110a, 110b, 110c, and 110d, the photoelectric conversion units 101-104 can be connected to each other. A wiring 162b is connected to the photoelectric conversion unit connectors 110a and 110d. A wiring 162a is connected to the photoelectric conversion unit connectors 110b and 110c.

[0097] [Other configurations of pixel planes] 10 is a plan view showing another configuration example of a pixel according to the fourth embodiment of the present disclosure. Similar to FIG. 9, this figure is a plan view showing a configuration example of a pixel 100. Photoelectric conversion unit connecting sections 110a-110d in this figure differ from the pixel 100 in FIG. 9 in that they are connected by a single wiring 162.

[0098] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0099] In this way, in the image sensor 1 according to the fourth embodiment of the present disclosure, the single charge holding unit 109 is disposed in the center of the pixel 100, which makes it possible to shorten the length of the wiring 163 connecting to the charge holding unit 109. This makes it possible to prevent a decrease in sensitivity when generating an image signal.

[0100] (5. Fifth Embodiment) In the image sensor 1 of the first embodiment described above, pixel separators 171 are arranged at the boundaries of the pixels 100. In contrast, the image sensor 1 of the fifth embodiment of the present disclosure differs from the first embodiment described above in that pixel separators 173 that penetrate the semiconductor substrate 130 are arranged at the boundaries of the pixels 100.

[0101] [Cross-sectional structure of pixel] 11 is a cross-sectional view showing an example of the configuration of a pixel according to the fifth embodiment of the present disclosure. Similar to FIG. 4, this figure is a cross-sectional view showing an example of the configuration of a pixel 100. The pixel 100 in this figure differs from the pixel 100 in FIG. 4 in that it includes a pixel separator 173 instead of the pixel separator 171.

[0102] The pixel separating portion 173 is a separating portion configured to have a shape that penetrates the semiconductor substrate 130. This pixel separating portion 173 can be configured by embedding an insulating member in a groove portion 177 that has a shape that penetrates the semiconductor substrate 130. The groove portion 177 is a groove portion that is formed from the surface side of the semiconductor substrate 130.

[0103] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0104] In this way, in the image sensor 1 according to the fifth embodiment of the present disclosure, pixel separating sections 173 that penetrate the semiconductor substrate 130 are arranged at the boundaries of the pixels 100. This makes it possible to improve the separating ability of the pixels 100.

[0105] (6. Sixth Embodiment) In the image sensor 1 of the first embodiment described above, the photoelectric conversion unit connection units 110 are arranged on the front surface side of the pixels 100. In contrast, the image sensor 1 of the sixth embodiment of the present disclosure differs from the first embodiment described above in that the photoelectric conversion unit connection units are arranged on the back surface side of the pixels 100.

[0106] [Cross-sectional structure of pixel] 12 is a cross-sectional view showing an example of the configuration of a pixel according to a sixth embodiment of the present disclosure. Similar to FIG. 4, this figure is a cross-sectional view showing an example of the configuration of a pixel 100. The pixel 100 in this figure differs from the pixel 100 in FIG. 4 in that a photoelectric conversion unit connection unit 119 is arranged instead of the photoelectric conversion unit connection unit 110, and the charge storage unit 109 is arranged in the center of the front surface side of the semiconductor substrate 130.

[0107] The photoelectric conversion unit connection 119 is disposed on the back surface side of the semiconductor substrate 130. Also, the semiconductor region 145 in the same figure is disposed on the back surface side of the semiconductor substrate 130. The photoelectric conversion unit connection 119 in the same figure includes a gate electrode 154. This gate electrode 154 can be formed by filling a conductive material such as polycrystalline silicon into a groove 157 formed from the back surface side of the semiconductor substrate 130. By configuring the groove 157 to the same depth as the groove 178 in FIG. 4, the gate electrode 154 can be extended in the thickness direction of the semiconductor substrate 130. The semiconductor region 145 can be extended, and the area of ​​the photoelectric conversion unit connection 119 can be widened.

[0108] The charge retention unit 109 in the figure is composed of a semiconductor region 143 arranged on the surface side of the semiconductor substrate 130. This semiconductor region 143 is arranged adjacent to the gate electrodes 151 and 152 of the charge transfer units 105 and 108. In this way, by arranging the charge retention unit 109, which is commonly connected to the charge transfer units 105-108, in a position overlapping with the photoelectric conversion unit connection unit 110 on the surface side of the semiconductor substrate 130, it is possible to reduce the number of elements arranged on the surface side of the semiconductor substrate 130. The wiring configuration of the wiring region 160 can be simplified.

[0109] On the other hand, since the photoelectric conversion unit connection 119 is disposed on the back surface side of the semiconductor substrate 130, wiring of the gate electrode 154 of the photoelectric conversion unit connection 119 is required on the back surface side of the semiconductor substrate 130. This wiring can be performed using a light-shielding film 193. The light-shielding film 193 in the same figure is also disposed in a position adjacent to the gate electrode 154 of the photoelectric conversion unit connection 110. As described above, the light-shielding film 193 can be made of tungsten. In other words, since the light-shielding film 193 is made of a conductor, it can be used as the signal line SC described in FIG. 2.

[0110] [Plane configuration of pixels] 13A to 13D are plan views showing configuration examples of a pixel according to a sixth embodiment of the present disclosure, and are plan views showing configuration examples of the back surface side of the pixel 100.

[0111] 13A is a diagram illustrating an example in which the light-shielding film 193 is disposed on the boundary of the pixel 100 and is further disposed in the boundary region of the photoelectric conversion units 101-104. The light-shielding film 193 disposed in the boundary region of the photoelectric conversion units 101-104 can be connected to the gate electrode 154 described above.

[0112] 13B is a diagram showing an example in which the number of light-shielding films 193 arranged in the boundary region between the photoelectric conversion units 101-104 is reduced to one. This makes it possible to reduce the area of ​​the light-shielding film 193 arranged on the back surface side of the semiconductor substrate 130, thereby mitigating the reduction in the amount of light incident on the pixel 100.

[0113] 13C is a diagram showing an example in which wiring 182 made of a transparent conductive film connects a light-shielding film 193 at the boundary of a pixel 100 to a photoelectric conversion unit connection unit 119. Since the wiring is made of a transparent conductive film, the decrease in the amount of light incident on the pixel 100 can be further reduced.

[0114] 13D is a diagram showing an example in which the number of wirings 182 arranged in the boundary region between the photoelectric conversion units 101-104 is reduced to one, which can further reduce the decrease in the amount of light incident on the pixel 100.

[0115] The light-shielding film 193 in the figure can be connected to the wiring 162 in the wiring region 160 by a through via that penetrates the semiconductor substrate 130. This through via can be arranged in a region outside the pixel region 3 described in FIG.

[0116] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0117] In this way, the image sensor 1 according to the sixth embodiment of the present disclosure can widen the area of ​​the photoelectric conversion unit connection 119 by arranging the photoelectric conversion unit connection 119 on the back surface side of the semiconductor substrate 130. Furthermore, the arrangement of elements on the front surface side of the semiconductor substrate 130 and the wiring configuration of the wiring region 160 can also be simplified.

[0118] (7. Seventh Embodiment) In the image sensor 1 of the first embodiment described above, the photoelectric conversion unit connection units 110 are arranged on the front surface side of the pixels 100. In contrast, the image sensor 1 of the seventh embodiment of the present disclosure differs from the first embodiment described above in that the photoelectric conversion unit connection units 119 are further arranged on the back surface side of the pixels 100.

[0119] [Cross-sectional structure of pixel] Fig. 14 is a cross-sectional view showing an example configuration of a pixel according to a seventh embodiment of the present disclosure. Similar to Fig. 4, Fig. 14 is a cross-sectional view showing an example configuration of a pixel 100. The pixel 100 in Fig. 14 differs from the pixel 100 in Fig. 4 in that the photoelectric conversion unit connection 119 described in Fig. 12 is further provided, and the semiconductor region 145 is provided in common in the photoelectric conversion unit connection units 110 and 119.

[0120] The semiconductor region 145 in the figure is configured in a shape that extends from near the front surface side to the back surface side of the semiconductor substrate 130. The semiconductor region 145 can be further expanded, and the area of ​​the photoelectric conversion unit connection section 119 can be widened.

[0121] Other than this, the configuration of the image sensor 1 is the same as the configuration of the image sensor 1 in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0122] In this way, in the imaging element 1 according to the seventh embodiment of the present disclosure, by arranging the photoelectric conversion unit connections 119 and 110 on both sides of the semiconductor substrate 130, the area of ​​the photoelectric conversion unit connection 119 can be made larger.

[0123] (8. Configuration example of imaging device) The imaging device 1 as described above can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, and other devices with imaging functions.

[0124] FIG. 15 is a block diagram showing an example of the configuration of an imaging device mounted on an electronic device.

[0125] As shown in Figure 15, the imaging device 701 includes an optical system 702, an imaging element 703, and a DSP (Digital Signal Processor) 704, and is configured by connecting the DSP 704, a display device 705, an operation system 706, a memory 708, a recording device 709, and a power supply system 710 via a bus 707, and is capable of capturing still images and moving images.

[0126] The optical system 702 is configured to have one or more lenses, and guides image light (incident light) from a subject to the image sensor 703 , forming an image on the light receiving surface (sensor section) of the image sensor 703 .

[0127] The image sensor 1 having any of the configuration examples described above is applied as the image sensor 703. Electrons are accumulated in the image sensor 703 for a certain period of time in accordance with an image formed on the light receiving surface via the optical system 702. A signal corresponding to the electrons accumulated in the image sensor 703 is input to the DSP 704.

[0128] The DSP 704 performs various signal processing on the signal from the image sensor 703 to acquire an image, and temporarily stores the image data in a memory 708. The image data stored in the memory 708 is recorded in a recording device 709 or supplied to a display device 705 to display the image. In addition, an operation system 706 accepts various operations by the user and supplies operation signals to each block of the image pickup device 701, and a power supply system 710 supplies the power necessary to drive each block of the image pickup device 701.

[0129] (9. Mobile Application Examples) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0130] FIG. 16 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0131] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 16, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0132] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating a braking force of the vehicle, etc.

[0133] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches may be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0134] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc., based on the received images.

[0135] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0136] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0137] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drivetrain control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including avoiding or mitigating collisions between vehicles, following based on the distance between vehicles, maintaining vehicle speed, warning of vehicle collisions, or warning of vehicle lane departure.

[0138] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0139] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information about the outside of the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0140] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to passengers in the vehicle or to the outside of the vehicle. In the example of Fig. 16, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as output devices. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0141] FIG. 17 is a diagram showing an example of the installation position of the imaging unit 12031.

[0142] In FIG. 17, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0143] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0144] 17 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

[0145] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0146] For example, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (for example, 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of automatic driving, which runs autonomously without relying on driver operation.

[0147] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drivetrain control unit 12010.

[0148] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the images captured by the image capturing units 12101 to 12104. The pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104, which are infrared cameras, and then performing pattern matching on a series of feature points that indicate the outline of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0149] An example of a vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 12031 in the configuration described above. Specifically, the imaging element 1 in FIG. 1 can be applied to the imaging unit 12031.

[0150] (10. Application to endoscopic surgery systems) The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0151] FIG. 18 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.

[0152] 18 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0153] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0154] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens towards an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0155] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected onto the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0156] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0157] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0158] The light source device 11203 is configured from a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing an operation site or the like.

[0159] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiating light, magnification, focal length, etc.) of the endoscope 11100.

[0160] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0161] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical site can be configured from a white light source configured from, for example, an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, making it possible to adjust the white balance of the captured image in the light source device 11203. In this case, it is also possible to capture images corresponding to each RGB in a time-division manner by irradiating the object of observation with laser light from each RGB laser light source in a time-division manner and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0162] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free of so-called blocked-up shadows and blown-out highlights.

[0163] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may be performed using fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow-band light and / or excitation light corresponding to such special light observation.

[0164] FIG. 19 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0165] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so that they can communicate with each other.

[0166] The lens unit 11401 is an optical system provided at the connection point with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0167] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (dimensional) display. 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0168] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately after the objective lens.

[0169] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0170] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0171] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0172] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0173] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0174] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0175] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0176] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data sent from the camera head 11102 .

[0177] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0178] Furthermore, the control unit 11413 causes the display device 11202 to display a captured image showing the surgical site, etc., based on the image signal that has been image processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0179] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0180] In the illustrated example, communication is performed by wire using the transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0181] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. Of the above-described configurations, the technology according to the present disclosure can be applied to the endoscope 11100 and the imaging unit 11402 of the camera head 11102. Specifically, the imaging element 1 in FIG. 1 can be applied to the imaging unit 11402.

[0182] Although an endoscopic surgery system has been described as an example here, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0183] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0184] The present technology can also be configured as follows. (1) a pixel including a plurality of photoelectric conversion units formed on a semiconductor substrate having a wiring region disposed on a front surface side thereof, the photoelectric conversion units performing photoelectric conversion of incident light from an object to generate electric charges; a photoelectric conversion unit connection unit that connects the plurality of photoelectric conversion units to each other; a charge holding unit that holds the generated charges; a plurality of charge transfer units arranged for the plurality of photoelectric conversion units, each of which transfers the charges generated by the photoelectric conversion units to the charge storage unit and stores the charges; an image signal generating unit that generates an image signal based on the stored charges; an on-chip lens disposed in the pixel and configured to commonly focus the incident light onto the plurality of photoelectric conversion units; An imaging element having (2) The imaging element described in (1) above, wherein the plurality of charge transfer units perform collective transfer, in which the charges generated by the plurality of photoelectric conversion units are commonly transferred to the charge holding unit, causing the charge holding unit to simultaneously hold the charges generated by the plurality of photoelectric conversion units, and individual transfer, in which the charges generated by the plurality of photoelectric conversion units are individually transferred to the charge holding unit. (3) The image sensor according to (2), wherein the photoelectric conversion unit connection unit connects the photoelectric conversion units together when the charges to be transferred by the batch transfer are generated. (4) the plurality of charge transfer units divide the plurality of photoelectric conversion units into two groups, transfer charges for each group, and cause the charges to be held in the charge holding unit; The image signal generation unit further generates a phase difference signal for detecting an image plane phase difference by pupil-dividing the image of the subject in the division direction based on the charges held for each group. The imaging element according to any one of (1) to (3). (5) The imaging element according to any one of (1) to (4), wherein the photoelectric conversion unit connection unit connects the photoelectric conversion units to each other by forming a channel in a semiconductor region adjacent to the plurality of photoelectric conversion units. (6) The image sensor according to (5), wherein the photoelectric conversion unit connection unit includes a gate electrode that forms the channel. (7) The imaging element according to (6), wherein the photoelectric conversion unit connection unit includes the gate electrode that is embedded in the semiconductor substrate. (8) The imaging element according to any one of (1) to (7), wherein the plurality of photoelectric conversion units are arranged in two rows and two columns. (9) The imaging element according to any one of (1) to (8), wherein the pixel is such that the incident light is irradiated onto a rear surface side of the semiconductor substrate. (10) The image sensor according to (9), wherein the photoelectric conversion unit connection portion is disposed on the back surface side of the semiconductor substrate. (11) The image sensor according to (10), wherein the charge holding portion is disposed on the front surface side of the semiconductor substrate and is disposed at a position overlapping the photoelectric conversion portion connection portion in a plan view. (12) The imaging element according to any one of (1) to (11), further comprising an intra-pixel separating section that separates the plurality of photoelectric conversion sections. (13) The imaging element according to any one of (1) to (12), further comprising a pixel separating section disposed at a boundary between the pixels. (14) The imaging element according to (13), wherein the pixel separating section is configured by an insulating member embedded in a groove formed in the semiconductor substrate. (15) a pixel including a plurality of photoelectric conversion units formed on a semiconductor substrate having a wiring region disposed on a front surface side thereof, the photoelectric conversion units performing photoelectric conversion of incident light from an object to generate electric charges; a photoelectric conversion unit connection unit that connects the plurality of photoelectric conversion units to each other; a charge holding unit that holds the generated charges; a plurality of charge transfer units arranged for the plurality of photoelectric conversion units, each of which transfers the charges generated by the photoelectric conversion units to the charge storage unit and stores the charges; an image signal generating unit that generates an image signal based on the stored charges; an on-chip lens disposed at the pixel and configured to commonly focus the incident light onto the plurality of photoelectric conversion units; a processing circuit for processing the generated image signal; An imaging device having the above configuration. [Explanation of symbols]

[0185] 1,703 image sensor 5 Column signal processing circuit 100 pixels 101 to 104 Photoelectric conversion unit 105~108 Charge transfer section 109, 109a, 109b Charge retention section 110, 110a, 110b, 110c, 110d, 119 Photoelectric conversion unit connection part 120, 120a, 120b Image signal generating unit 130 Semiconductor substrate 141~145 Semiconductor area 151~154 Gate electrode 160 Wiring area 162, 162b, 162a, 163, 163a, 163b, 182 wiring 171, 173 Pixel separation section 172 Intra-pixel separation section 193 Light-shielding film 194 On-chip lens 701 Imaging device 11402, 12031, 12101~12105 Imaging unit

Claims

1. a pixel including a plurality of photoelectric conversion units formed on a semiconductor substrate having a wiring region disposed on a front surface side thereof, the photoelectric conversion units performing photoelectric conversion of incident light from an object to generate electric charges; a photoelectric conversion unit connection unit that connects the plurality of photoelectric conversion units to each other; a charge holding unit that holds the generated charges; a plurality of charge transfer units arranged for the plurality of photoelectric conversion units, each of which transfers the charges generated by the photoelectric conversion units to the charge storage unit and stores the charges; an image signal generating unit that generates an image signal based on the stored charges; an on-chip lens disposed in the pixel and configured to commonly focus the incident light onto the plurality of photoelectric conversion units; and the plurality of charge transfer units perform collective transfer in which the charges generated by the plurality of photoelectric conversion units are commonly transferred to the charge holding unit, and the charges generated by the plurality of photoelectric conversion units are simultaneously held in the charge holding unit, and individual transfer in which the charges generated by the plurality of photoelectric conversion units are individually transferred to the charge holding unit, the photoelectric conversion unit connection unit connects the photoelectric conversion units to each other when the charges to be transferred by the collective transfer are generated, and disconnects the photoelectric conversion units from each other when the charges to be transferred by the individual transfer are generated and during the individual transfer; the photoelectric conversion unit connection unit connects the photoelectric conversion units to each other by forming a channel in a semiconductor region adjacent to the plurality of photoelectric conversion units; The photoelectric conversion unit connection unit includes a gate electrode that forms the channel. Image sensor.

2. the plurality of charge transfer units divide the plurality of photoelectric conversion units into two groups, transfer charges for each group, and cause the charges to be held in the charge holding unit; The image signal generation unit further generates a phase difference signal for detecting an image plane phase difference by pupil-dividing the image of the subject in the division direction based on the charges held for each group. The imaging device according to claim 1 .

3. The image sensor according to claim 1 , wherein the photoelectric conversion unit connection portion includes the gate electrode that is embedded in the semiconductor substrate.

4. The image sensor according to claim 1 , wherein the plurality of photoelectric conversion units are arranged in two rows and two columns.

5. An imaging element as described in Claim 4, wherein the photoelectric conversion unit connection portion is arranged in the center of the pixel when viewed in a plane.

6. An imaging element as described in Claim 4, wherein the charge holding portion is arranged in the center of the pixel when viewed in a plane.

7. An imaging element as described in claim 4 having a plurality of photoelectric conversion unit connection parts.

8. An imaging element as described in Claim 1, wherein the photoelectric conversion unit connection portion has a plurality of the gate electrodes.

9. The imaging device according to claim 1 , wherein the incident light is irradiated onto a rear surface side of the semiconductor substrate of the pixel.

10. The image sensor according to claim 9 , wherein the photoelectric conversion unit connection portion is disposed on the back surface side of the semiconductor substrate.

11. The image sensor according to claim 10 , wherein the charge retention portion is disposed on the front surface side of the semiconductor substrate and is disposed at a position overlapping the photoelectric conversion portion connection portion in a plan view.

12. The image sensor according to claim 1 , further comprising an intra-pixel separating section separating the plurality of photoelectric conversion sections.

13. The imaging device according to claim 1 , further comprising a pixel separating section disposed at a boundary between the pixels.

14. The image sensor according to claim 13 , wherein the pixel separating section is formed of an insulating member embedded in a groove formed in the semiconductor substrate.

15. a pixel including a plurality of photoelectric conversion units formed on a semiconductor substrate having a wiring region disposed on a front surface side thereof, the photoelectric conversion units performing photoelectric conversion of incident light from an object to generate electric charges; a photoelectric conversion unit connection unit that connects the plurality of photoelectric conversion units to each other; a charge holding unit that holds the generated charges; a plurality of charge transfer units arranged for the plurality of photoelectric conversion units, each of which transfers the charges generated by the photoelectric conversion units to the charge storage unit and stores the charges; an image signal generating unit that generates an image signal based on the stored charges; an on-chip lens disposed at the pixel and configured to commonly focus the incident light onto the plurality of photoelectric conversion units; a processing circuit for processing the generated image signal; and the plurality of charge transfer units perform collective transfer in which the charges generated by the plurality of photoelectric conversion units are commonly transferred to the charge holding unit, and the charges generated by the plurality of photoelectric conversion units are simultaneously held in the charge holding unit, and individual transfer in which the charges generated by the plurality of photoelectric conversion units are individually transferred to the charge holding unit, the photoelectric conversion unit connection unit connects the photoelectric conversion units to each other when the charges to be transferred by the collective transfer are generated, and disconnects the photoelectric conversion units from each other when the charges to be transferred by the individual transfer are generated and during the individual transfer; the photoelectric conversion unit connection unit connects the photoelectric conversion units to each other by forming a channel in a semiconductor region adjacent to the plurality of photoelectric conversion units; The photoelectric conversion unit connection unit includes a gate electrode that forms the channel. Imaging device.

Images