Image pickup element and image pickup device

Abstract

The present invention reduces the phase difference detection error in an imaging element provided with a phase difference pixel, wherein the phase difference pixel is constructed by providing an on-chip lens shared by a pair of pixels. The imaging element includes a pixel, a separate on-chip lens, a plurality of phase difference pixels, a shared on-chip lens, and a pixel circuit. The pixel is provided with a photoelectric conversion unit for photoelectric conversion corresponding to incident light, and a charge transfer unit for transmitting the charge generated by the photoelectric conversion. A separate on-chip lens is provided in each pixel and converges the incident light individually. The phase difference pixels are each provided with a photoelectric conversion unit and a charge transfer unit, and are arranged adjacent to each other and detect the phase difference. The shared on-chip lens is provided to be shared by a plurality of phase difference pixels and to converge the incident light together. The pixel circuit is formed on a semiconductor substrate and generates an image signal based on the transferred charge. The charge transfer unit of a plurality of phase difference pixels is provided in an area between the shared on-chip lens and the separate on-chip lens.

Description

Technical Field

[0001] The present disclosure relates to an imaging element and an imaging device. Specifically, the present technology relates to an imaging element for detecting a phase difference of a subject and an imaging device using the imaging element. Background Art

[0002] Conventionally, in a back-illuminated imaging element (in which light from a subject is irradiated on the back side of a semiconductor substrate on which a photoelectric conversion element such as a photodiode is formed), an imaging element is used that transfers the charge generated by the photoelectric conversion on the back side of the semiconductor substrate to the front side of the semiconductor substrate. For example, an imaging element is used in which an organic photoelectric conversion film is arranged adjacent to the back side of the semiconductor substrate, and the charge generated by the photoelectric conversion in the organic photoelectric conversion film is transferred to the front side of the semiconductor substrate by using a through electrode (for example, see Patent Document 1). The charge transferred by the through electrode is converted into an image signal by a circuit element arranged on the front side of the semiconductor substrate. In addition, the through electrode is a region between pixels that is a photoelectric conversion unit of incident light and is arranged between pixels.

[0003] In addition, for the imaging element, a phase difference pixel is also proposed. Here, the phase difference pixel is a pixel for detecting the phase difference of the subject. The focus position of the subject can be detected by the detected phase difference, and it is suitable for automatic focusing to focus the camera lens. The phase difference can be detected by pupil splitting. This pupil splitting is a method of detecting the phase difference by arranging a pair of pixels, which convert the incident light transmitted through the right and left sides of the camera lens into image signals respectively. The focus position can be detected by detecting the phase difference between the image based on the image signal transmitted through the right side of the camera lens and the image of the image signal transmitted through the left side of the camera lens. The phase difference pixel used for pupil splitting can be composed of pixels shielded on the left or right side of the pixel. By irradiating the shielded pixels on the left or right side with the incident light focused by the on-chip lens, the incident light transmitted through the right or left side of the camera lens can be photoelectrically converted. However, the shading causes the output of the image signal of the phase difference pixel to be halved. There is a problem of reduced detection accuracy of the phase difference.

[0004] Therefore, a method of performing pupil division by arranging an on-chip lens (shared on-chip lens) for two adjacent pixels has been proposed. By focusing incident light between the pixels of the two pixels using a shared on-chip lens, incident light passing through the right and left sides of the camera lens can be photoelectrically converted. Since the pixels are not shielded, it is possible to prevent the output of the image signal from being reduced.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2016 / 143531 Summary of the invention

[0008] Technical issues to be solved

[0009] In the above-mentioned prior art, the pupil division method using a shared on-chip lens has a problem of reduced detection accuracy of the phase difference. Since the shared on-chip lens converges the incident light between pixels, there is a problem that when a structure that does not contribute to photoelectric conversion, such as the above-mentioned through electrode, is arranged between the pixels, a difference is generated between the respective image signals of a pair of phase difference pixels, and the error of phase difference detection increases.

[0010] The present disclosure has been made in view of the above-mentioned problem, and an object thereof is to reduce an error in phase difference detection of an image pickup element including a phase difference pixel constituted by arranging an on-chip lens in common for a pair of pixels.

[0011] Solutions to technical problems

[0012] The present disclosure is proposed to solve the above-mentioned problems, and its first aspect is an imaging element, comprising: a pixel, the pixel including a photoelectric conversion unit and a charge transfer unit, the photoelectric conversion unit being configured to perform photoelectric conversion according to incident light, and the charge transfer unit being configured to transfer charges generated by the above-mentioned photoelectric conversion; a separate on-chip lens, the separate on-chip lens being arranged for each of the above-mentioned pixels and being configured to individually converge the above-mentioned incident light; a plurality of phase difference pixels, the phase difference pixels each including the above-mentioned photoelectric conversion unit and the above-mentioned charge transfer unit, and being arranged adjacent to each other to detect a phase difference; a common on-chip lens, the common on-chip lens being arranged in common for the above-mentioned plurality of phase difference pixels and being configured to collectively converge the above-mentioned incident light; and a pixel circuit, the pixel circuit being formed in a semiconductor substrate and being configured to generate an image signal based on the above-mentioned charges being transferred, wherein the charge transfer units of the above-mentioned plurality of phase difference pixels are arranged in an area between the above-mentioned common on-chip lens and the above-mentioned individual on-chip lens.

[0013] Furthermore, in the first aspect, the pixel circuit may be formed on the front surface side of the semiconductor substrate.

[0014] Furthermore, in the first aspect, the photoelectric conversion unit may perform photoelectric conversion on the incident light incident on a back surface that is a surface formed on the semiconductor substrate and different from the front surface.

[0015] Furthermore, in the first aspect, the charge transfer unit may include a vertical transistor configured to transfer charges in a thickness direction of the semiconductor substrate.

[0016] Furthermore, in the first aspect, the above-mentioned photoelectric conversion unit may include a photoelectric conversion film arranged adjacent to the back surface side of the above-mentioned semiconductor substrate.

[0017] Furthermore, in the first aspect, the charge transfer unit may include a through electrode, wherein the through electrode is an electrode that passes through the semiconductor substrate.

[0018] Furthermore, in the first aspect, a color filter that transmits light having a predetermined wavelength among the incident light may be further provided.

[0019] Furthermore, in the first aspect, the color filter may be disposed between the photoelectric conversion film and the individual on-chip electrodes and the common on-chip electrode.

[0020] Furthermore, in the first aspect, the color filter may be disposed between the photoelectric conversion film and the semiconductor substrate.

[0021] In addition, in the first aspect, a partition unit is further included which is arranged between the photoelectric conversion units of the phase difference pixel.

[0022] In addition, the second aspect of the present disclosure is an imaging device, which includes: a pixel, the pixel including a photoelectric conversion unit and a charge transfer unit, the photoelectric conversion unit is configured to perform photoelectric conversion according to incident light, and the charge transfer unit is configured to transfer the charge generated by the photoelectric conversion; a separate on-chip lens, the separate on-chip lens is arranged for each of the above-mentioned pixels and is configured to separately converge the above-mentioned incident light; a plurality of phase difference pixels, the phase difference pixels each including the above-mentioned photoelectric conversion unit and the above-mentioned charge transfer unit, and are arranged adjacent to each other to detect phase difference; a shared on-chip lens, the shared on-chip lens is jointly arranged for the above-mentioned plurality of phase difference pixels and is configured to jointly converge the above-mentioned incident light; a pixel circuit, the pixel circuit is formed in a semiconductor substrate and is configured to generate an image signal based on the above-mentioned transferred charge, and a processing circuit, the processing circuit is configured to process the generated image signal, wherein the above-mentioned charge transfer unit of the above-mentioned plurality of phase difference pixels is arranged in an area between the above-mentioned shared on-chip lens and the above-mentioned separate on-chip lens.

[0023] By adopting the above aspect, there is an effect that the charge transfer unit is arranged in a region different from the region where the common on-chip lens is arranged in a plan view, and the influence of the charge transfer unit on the condensation of the common on-chip lens is expected to be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a diagram showing a configuration example of an image pickup element according to an embodiment of the present disclosure.

[0025] Figure 2is a circuit diagram showing a configuration example of a pixel according to the first embodiment of the present disclosure.

[0026] Figure 3 is a cross-sectional view showing a configuration example of a pixel according to the first embodiment of the present disclosure.

[0027] Figure 4 : is a view showing a configuration example of a pixel array unit according to the first embodiment of the present disclosure.

[0028] Figure 5 is a cross-sectional view showing a configuration example of a phase difference pixel according to the first embodiment of the present disclosure.

[0029] Figure 6 is a cross-sectional view showing a configuration example of a phase difference pixel according to a second embodiment of the present disclosure.

[0030] Figure 7 is a circuit diagram showing a configuration example of a pixel according to a third embodiment of the present disclosure.

[0031] Figure 8 is a cross-sectional view showing a configuration example of a pixel according to a third embodiment of the present disclosure.

[0032] Fig. 9 : is a view showing a configuration example of a pixel array unit according to a third embodiment of the present disclosure.

[0033] Fig.10 is a circuit diagram showing a configuration example of a pixel according to a fourth embodiment of the present disclosure.

[0034] Fig.11 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure.

[0035] Fig.12 : is a view showing a configuration example of a pixel array unit according to a fourth embodiment of the present disclosure.

[0036] Fig.13 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure.

[0037] Fig.14 is a cross-sectional view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure.

[0038] Fig.15 is a circuit diagram showing a configuration example of a pixel according to a seventh embodiment of the present disclosure.

[0039] Fig.16 is a cross-sectional view showing a configuration example of a pixel according to a seventh embodiment of the present disclosure.

[0040] Fig.17is a view showing a configuration example of a pixel array unit according to a seventh embodiment of the present disclosure.

[0041] Fig.18 : is a block diagram showing a schematic configuration example of a camera as an example of an image pickup device to which the present technology can be applied.

[0042] Fig.19 is a view showing an example of a schematic configuration of an endoscopic surgery system.

[0043] Fig. 20 is a block diagram showing an example of the functional configuration of a camera and a CCU.

[0044] Fig.21 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0045] Fig. 22 It is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection unit and the imaging unit. DETAILED DESCRIPTION

[0046] Hereinafter, an embodiment (hereinafter referred to as an embodiment) for implementing the present disclosure will be described with reference to the accompanying drawings. In the following drawings, the same or similar parts are represented by the same or similar reference numerals. In addition, the embodiments will be described in the following order.

[0047] 1. First Embodiment

[0048] 2. Second Embodiment

[0049] 3. Third embodiment

[0050] 4. Fourth embodiment

[0051] 5. Fifth embodiment

[0052] 6. Sixth embodiment

[0053] 7. Seventh embodiment

[0054] 8. Camera application examples

[0055] 9. Application examples of endoscopic surgery systems

[0056] 10. Application examples for mobile objects

[0057] <1. First Embodiment>

[0058] [Structure of the imaging element]

[0059] Figure 1 1 is a diagram showing a configuration example of an image pickup element according to an embodiment of the present disclosure. In the figure, an image pickup element 1 includes a pixel array unit 2, a vertical drive unit 3, a column signal processing unit 4, and a control unit 5.

[0060] The pixel array unit 2 is constructed by arranging pixels 100 and phase difference pixels 200 in a two-dimensional lattice shape. Here, the pixel 100 generates an image signal corresponding to the irradiated light. The pixel 100 includes a photoelectric conversion unit that generates a charge according to the irradiated light. In addition, the pixel 100 also includes a pixel circuit. The pixel circuit generates an image signal based on the charge generated by the photoelectric conversion unit. The generation of the image signal is controlled by a control signal generated by the vertical drive unit 3 described below. In the pixel array unit 2, signal lines 6 and 7 are arranged in an XY matrix. Signal line 6 is a signal line that transmits a control signal of the pixel circuit in the pixel 100, which is arranged for each row of the pixel array unit 2 and is wired to be shared by the pixels 100 arranged in each row. Signal line 7 is a signal line that transmits an image signal generated by the pixel circuit of the pixel 100, which is arranged for each column of the pixel array unit 2 and is wired to be shared by the pixels 100 arranged in each column. These photoelectric conversion units and pixel circuits are formed in a semiconductor substrate.

[0061] In addition, the phase difference pixel 200 is a pixel for detecting the phase difference of the subject. The shaded rectangle of the pixel array unit 2 in the figure represents the phase difference pixel 200. The phase difference pixel 200 performs pupil division, and two adjacent phase difference pixels 200 are arranged in pairs. Similar to the pixel 100, a photoelectric conversion unit and a pixel circuit are also arranged in the phase difference pixel 200, and signal lines 6 and 7 are connected.

[0062] The vertical drive unit 3 generates a control signal for the pixel circuits of the pixel 100 and the phase difference pixel 200. The vertical drive unit 3 transmits the generated control signal to the pixel 100 via the signal line 6 in the figure. The column signal processing unit 4 processes the image signal generated by the pixel 100 and the phase difference pixel 200. The column signal processing unit 4 processes the image signal transmitted from the pixel 100 via the signal line 7 in the figure. The processing in the column signal processing unit 4 corresponds to, for example, analog-to-digital conversion for converting analog image signals generated in the pixel 100 and the phase difference pixel 200 into digital image signals. The image signal processed by the column signal processing unit 4 is output as an image signal of the imaging element 1. The control unit 5 controls the entire imaging element 1, and the control unit 5 controls the imaging element 1 by generating and outputting control signals for controlling the vertical drive unit 3 and the column signal processing unit 4. The control signal generated by the control unit 5 is transmitted to the vertical drive unit 3 and the column signal processing unit 4 via the signal lines 8 and 9, respectively. Note that the column signal processing unit 4 is an example of a processing circuit described in the claims.

[0063] [Pixel Circuit Structure]

[0064] Figure 21 is a circuit diagram illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. The figure is a circuit diagram showing a configuration example of a pixel 100. The pixel 100 in the figure includes a photoelectric conversion unit 11, a charge transfer unit 12, a charge holding unit 21, and MOS transistors 22 to 24. Note that in the figure, it is assumed that the charge transfer unit 12 is a MOS transistor.

[0065] The anode of the photoelectric conversion unit 11 is grounded, and the cathode is connected to the source of the charge transfer unit 12. The drain of the charge transfer unit 12 is connected to the source of the MOS transistor 22, the gate of the MOS transistor 23, and one end of the charge holding unit 21. The other end of the charge holding unit 21 is grounded. The drains of the MOS transistors 22 and 23 are commonly connected to the power supply line Vdd, and the source of the MOS transistor 23 is connected to the drain of the MOS transistor 24. The source of the MOS transistor 24 is connected to the signal line 7. The charge transfer unit 12 and the gates of the MOS transistors 22 and 24 are respectively connected to the transmission signal line TR, the reset signal line RST, and the selection signal line SEL. Note that the transmission signal line TR, the reset signal line RST, and the selection signal line SEL constitute the signal line 6.

[0066] As described above, the photoelectric conversion unit 11 generates charges corresponding to the irradiated light. As this photoelectric conversion unit 11, a photodiode can be used. In addition, the charge holding unit 21 and the MOS transistors 22 to 24 constitute the pixel circuit 20.

[0067] The charge transfer unit 12 is a transistor for transferring the charge generated by the photoelectric conversion of the photoelectric conversion unit 11 to the charge holding unit 21. The transfer of the charge in the charge transfer unit 12 is controlled by a signal transmitted by the transmission signal line TR. The charge holding unit 21 is a capacitor that holds the charge transferred by the charge transfer unit 12. The MOS transistor 23 is a transistor that generates a signal based on the charge held in the charge holding unit 21. The MOS transistor 24 is a transistor that outputs the signal generated by the MOS transistor 23 to the signal line 7 as an image signal. This MOS transistor 24 is controlled by a signal transmitted through the selection signal line SEL.

[0068] The MOS transistor 22 is a transistor that resets the charge holding unit 21 by releasing the charge held in the charge holding unit 21 to the power supply line Vdd. The resetting of the MOS transistor 22 is controlled by the charge transferred through the reset signal line RST and is performed before the charge transfer unit 12 transfers the charge. It should be noted that, at the time of such resetting, the photoelectric conversion unit 11 can also be reset by electrically connecting the charge transfer unit 12. In this way, the pixel circuit 20 converts the charge generated by the photoelectric conversion unit 11 into an image signal.

[0069] Note that the pixel circuit 20 is a circuit that generates an image signal based on the charge generated by the photoelectric conversion unit 11 and transferred by the charge transfer unit 12. Note that the circuit configuration in the figure can also be applied to the phase difference pixel 200.

[0070] [Pixel structure]

[0071] Figure 3 1 is a cross-sectional view showing a configuration example of a pixel according to the first embodiment of the present disclosure. The figure is a schematic cross-sectional view showing a configuration example of a pixel 100. The pixel 100 in the figure includes a semiconductor substrate 110, a wiring region 130, a fixed charge film 141, a separation unit 142, a light shielding film 143, a color filter 150, a flattening film 144, and an on-chip lens 181.

[0072] The semiconductor substrate 110 is a semiconductor substrate on which the photoelectric conversion unit 11 of the pixel 100, the diffusion region of the elements of the pixel circuit 20, etc. are formed. The semiconductor substrate 110 may include, for example, silicon (Si). The photoelectric conversion unit 11 and the diffusion region of the elements of the pixel circuit 20 are arranged in a well region (well region) formed in the semiconductor substrate 110. For convenience, it is assumed that the semiconductor substrate 110 in the figure is constructed in a p-type well region. By arranging an n-type semiconductor region in the semiconductor substrate 110 as a p-type well region, the photoelectric conversion unit 11, etc. can be formed. The rectangle inside the semiconductor substrate 110 represents the n-type semiconductor region. On the front side of the semiconductor substrate 110, a wiring region 130 to be described below is formed.

[0073] The photoelectric conversion unit 11 includes an n-type semiconductor region 111. Specifically, a photodiode composed of a pn junction at the interface between the n-type semiconductor region 111 and the surrounding p-type well region corresponds to the photoelectric conversion unit 11. When incident light is irradiated, photoelectric conversion occurs in the n-type semiconductor region 111. Among the charges generated by this photoelectric conversion, electrons are accumulated in the n-type semiconductor region 111. Note that the n-type semiconductor region 111 is arranged on the back side of the semiconductor substrate 110, and performs photoelectric conversion on the incident light irradiated on the back side. Such an imaging element 1 is called a back-illuminated imaging element.

[0074] On the front side of the semiconductor substrate 110, n-type semiconductor regions 112 to 115 are formed. In addition, gate electrodes 122 to 124 are arranged on the front side of the semiconductor substrate 110 via a gate insulating film. These constitute MOS transistors 22 to 24 and a charge holding unit 21, and constitute a pixel circuit 20.

[0075] The n-type semiconductor region 112 is a semiconductor region constituting the charge holding unit 21. This n-type semiconductor region 112 is called a floating diffusion region, and holds the charge transferred by the charge transfer unit 12. In addition, the n-type semiconductor region 112, the n-type semiconductor region 113, and the gate electrode 122 constitute the MOS transistor 22. The n-type semiconductor regions 112 and 113 correspond to the source and drain of the MOS transistor 22, respectively. The well region near the gate electrode 122 between the n-type semiconductor regions 112 and 113 corresponds to the channel region of the MOS transistor 22.

[0076] In addition, the n-type semiconductor region 113, the n-type semiconductor region 114, and the gate electrode 123 constitute the MOS transistor 23. The n-type semiconductor regions 113 and 114 correspond to the drain and source of the MOS transistor 23, respectively. In addition, the n-type semiconductor region 114, the n-type semiconductor region 115, and the gate electrode 124 constitute the MOS transistor 24. The n-type semiconductor regions 114 and 115 correspond to the drain and source of the MOS transistor 24, respectively.

[0077] In addition, the charge transfer unit 12 is a MOS transistor including an n-type semiconductor region 111, an n-type semiconductor region 112, and a gate electrode 121. The n-type semiconductor regions 111 and 112 correspond to the source and drain of the charge transfer unit 12, respectively. The gate electrode 121 is formed in a shape in which an electrode is buried in a hole formed in the semiconductor substrate 110 via a gate insulating film, and is arranged near the n-type semiconductor regions 111 and 112. By applying a gate voltage to the gate electrode 121, a channel is formed in a well region near the gate electrode 121, and the n-type semiconductor regions 111 and 112 are brought into a conducting state. As a result, the charge accumulated in the n-type semiconductor region 111 of the photoelectric conversion unit 11 is transferred to the n-type semiconductor region 112 as a floating diffusion region. A transistor configured to transfer charge in a direction perpendicular to the semiconductor substrate 110 in this manner is referred to as a vertical transistor. The gate insulating film may include, for example, silicon oxide (SiO2), silicon nitride (SiN), or a high dielectric film. The gate electrode 121 may include, for example, metal or polysilicon.

[0078] The wiring region 130 is a region arranged adjacent to the front side of the semiconductor substrate 110 and formed with wiring of elements formed in the semiconductor substrate 110. In the wiring region 130, an insulating layer 131 and a wiring layer 132 are arranged. The wiring layer 132 is a wiring including a metal such as copper (Cu) and configured to transmit a signal to an element formed in the semiconductor substrate 110. The insulating layer 131 insulates the wiring layer 132. The insulating layer 131 may include, for example, SiO2. In addition, the insulating layer 131 and the wiring layer 132 may be configured as a multilayer. Note that in the figure, the insulating layer 131 between the gate electrodes 122 to 124 and the semiconductor substrate 110 is referred to as a gate oxide film. In addition, the wiring layer 132, the semiconductor region, the gate electrode 122, etc. are connected by a contact plug 133.

[0079] The fixed charge film 141 is formed at the interface on the back side of the semiconductor substrate 110 to pin the interface state of the semiconductor substrate 110. The fixed charge film 141 includes a material having a negative fixed charge and accumulates holes near the interface of the semiconductor substrate 110. The interface state is pinned by the accumulated holes. As a result, the influence of the dark current caused by the interface state can be reduced.

[0080] The partition unit 142 is arranged in a wall shape of the semiconductor substrate 110 surrounding the pixel 100 to partition the semiconductor substrate 110. In addition, the partition unit 142 shields incident light from the adjacent pixel 100. This partition unit 142 can be constructed by arranging a metal such as tungsten (W) in a groove formed in the semiconductor substrate 110. The partition unit 142 in the figure is arranged in the groove formed in the semiconductor substrate 110 via the fixed charge film 141.

[0081] The light shielding film 143 is provided on the back side of the semiconductor substrate 110 to shield the incident light. The light shielding film is provided at the boundary of the pixel 100 and shields the light passing through the color filter 150 of the adjacent pixel 100. As a result, the occurrence of color mixing can be prevented. Similar to the partition unit 142, the light shielding film 143 may include a metal, such as W, etc.

[0082] The color filter 150 is a filter that transmits light of a predetermined wavelength in the incident light. As the color filter 150, for example, each color filter 150 that transmits red light, green light, and blue light can be arranged in the pixel 100. In addition, a color filter 150 that transmits infrared light can also be arranged in the pixel 100.

[0083] The planarization film 144 is a film that planarizes the back surface side of the pixel 100 where the color filter 150 is formed. The planarization film 144 may include a coating type insulating material.

[0084] The on-chip lens 181 is a lens that focuses incident light. The on-chip lens 181 is formed in a hemispherical shape and focuses the incident light on the photoelectric conversion unit 11 (n-type semiconductor region 111) of the semiconductor substrate 110. The on-chip lens 181 in the figure focuses the incident light 150 via the color filter 150. The on-chip lens 181 may include, for example, an organic material having a refractive index of 1.0 to 1.3. Note that the on-chip lens 181 is an example of a separate on-chip lens described in the claims.

[0085] Note that, in the phase difference pixel 200 , a shared on-chip lens 182 described later is arranged instead of the on-chip lens 181 . The other configuration of the phase difference pixel 200 may be similar to that of the pixel 100 .

[0086] [Structure of pixel array unit]

[0087] Figure 4 1 is a view showing a configuration example of a pixel array unit according to a first embodiment of the present disclosure. The figure is a plan view showing a configuration example of a pixel 100 and a phase difference pixel 200 in a pixel array unit 2. In the figure, a long dashed rectangle represents a pixel 100, and a short dashed rectangle represents a phase difference pixel 200. In addition, in the pixel 100 and the phase difference pixel 200, a rectangle with oblique line shading represents an area of ​​a pixel circuit 20. The rectangle in the pixel circuit 20 represents an n-type semiconductor region 112 of a charge holding unit 21. In addition, a rectangle with grid shading represents a gate electrode 121 of a vertical transistor. A rectangle adjacent to the pixel circuit 20 and the gate electrode 121 represents an n-type semiconductor region 111 of a photoelectric conversion unit 11. The gate electrode 121 of the charge transfer unit 12 is provided at a corner of the pixel 100, etc., and the n-type semiconductor region 111 and the pixel circuit 20 are arranged adjacent to each other, respectively.

[0088] The single-point dashed circle in the pixel 100 represents the on-chip lens 181. In addition, the single-point dashed oval in the phase difference pixel 200 represents the shared on-chip lens 182. As shown in the figure, the on-chip lens 181 is arranged for each pixel 100, and the shared on-chip lens 182 is arranged for two adjacent phase difference pixels 200. Note that the shape of the shared on-chip lens 182 is not limited to this example. For example, the shared on-chip lens 182 can also be formed into an ellipse. The two adjacent phase difference pixels 200 in the figure perform pupil division in the adjacent direction. In the pixel array unit 2 in the figure, the subject is subjected to lateral pupil division.

[0089] The charge of the n-type semiconductor region 111 of the photoelectric conversion unit 11 is transferred in a direction changed by 90 degrees in a plan view through the charge transfer unit 12 configured as a vertical transistor. The charge transfer unit 12 is arranged in a region that does not overlap with the shared on-chip lens 182 in the phase difference pixel 200. That is, the charge transfer unit 12 including the vertical transistor having the gate electrode 121 that does not contribute to the photoelectric conversion is arranged in a region between the shared on-chip lens 182 and the on-chip lens 181 on the surface irradiated with the incident light. As a result, this can eliminate the influence of the charge transfer unit 12 on the focusing of the incident light by the shared on-chip lens 182 in the phase difference pixel 200. This is because the gate electrode 121 of the charge transfer unit 12 does not shield the optical path of the incident light focused by the shared on-chip lens 182.

[0090] [Structure of Phase Difference Pixel]

[0091] Figure 5 1 is a cross-sectional view showing a configuration example of a phase difference pixel according to the first embodiment of the present disclosure. Figure 4 Cross-sectional view taken along line a-a'.

[0092] As described above, the shared on-chip lens 182 is arranged as a shared on-chip lens for two phase difference pixels 200. In addition, the shared on-chip lens 182 forms a focus between the two phase difference pixels 200 near the back surface of the semiconductor substrate 110. As a result, incident light from the subject that has passed through the left side of the imaging lens enters the photoelectric conversion unit 11 (n-type semiconductor region 111) of the right phase difference pixel 200, and incident light that has passed through the right side of the imaging lens enters the photoelectric conversion unit 11 of the left phase difference pixel 200. In the figure, the solid arrow represents the incident light 301 that has passed through the left side of the imaging lens, and the dotted arrow represents the incident light 302 that has passed through the right side of the imaging lens. In this way, by arranging the shared on-chip lens 182 in two adjacent phase difference pixels 200, pupil division can be performed to detect the phase difference.

[0093] Note that light from the subject that has passed through the focal point between the two phase difference pixels 200 near the back side of the semiconductor substrate 110 enters the n-type semiconductor region 111 and is photoelectrically converted. When a structure that does not contribute to photoelectric conversion, such as the gate electrode 121 of the charge transfer unit 12, is arranged near the n-type semiconductor region 111 where the incident light arrives, the photoelectric conversion of the incident light is hindered. In addition, when such a structure is arranged asymmetrically in the two phase difference pixels 200, a sensitivity difference occurs between the two phase difference pixels 200, and a difference occurs in the image signal output. Since a difference in the image signal that is not caused by the phase difference of the incident light is generated, an error in phase difference detection occurs.

[0094] Even in the case where a structure that does not contribute to photoelectric conversion is arranged near the photoelectric conversion unit 11, it is considered that no difference between image signals will be generated by constructing the two phase difference pixels 200 to be completely symmetrical. However, it is difficult to construct the two phase difference pixels 200 to be completely symmetrical. In addition, in the phase difference pixels 200 arranged at the peripheral edge portion of the pixel array unit 2, the image height increases, and the incident light enters the phase difference pixels 200 obliquely. Therefore, the influence of the structure that does not contribute to photoelectric conversion increases. Therefore, as mentioned above Figure 4 As shown in , the charge transfer unit 12 having the gate electrode 121 as a structure that does not contribute to photoelectric conversion is arranged in a region different from the region where the common on-chip lens 182 is arranged. As a result, it is possible to reduce the output difference of the image signals of the two phase difference pixels 200. Also in this case, by symmetrically configuring the two phase difference pixels 200, it is possible to further reduce the output difference of the image signals of the two phase difference pixels 200.

[0095] As described above, the image pickup element 1 according to the first embodiment of the present disclosure includes two phase difference pixels 200 arranged with the common on-chip lens 182. In the image pickup element 1 according to the first embodiment of the present disclosure, the charge transfer unit 12 having the gate electrode 121 as a structure that does not contribute to photoelectric conversion is arranged between the common on-chip lens 182 and the on-chip lens 181 of the pixel 100. As a result, the difference in the image signal of the phase difference pixel 200 can be reduced, and the error of the phase difference detection of the phase difference pixel 200 can be reduced.

[0096] <2. Second Embodiment>

[0097] In the image sensor 1 of the first embodiment, two phase difference pixels 200 are arranged adjacent to each other. On the other hand, the image sensor 1 of the second embodiment of the present disclosure is different from the first embodiment in that a partition unit is arranged between two adjacent phase difference pixels 200 in the semiconductor substrate 110 .

[0098] [Structure of Phase Difference Pixel]

[0099] Figure 6 2 is a cross-sectional view showing a configuration example of a phase difference pixel according to a second embodiment of the present disclosure. Figure 5 Similarly, this figure is a cross-sectional view showing a configuration example of the phase difference pixel 200. Figure 5 The phase difference pixel 200 described in FIG. 1 is different in that a partition unit 142 is arranged between two phase difference pixels 200 in the semiconductor substrate 110 .

[0100] In the phase difference pixel 200 in the figure, the partition unit 142 is arranged in the well region between the n-type semiconductor regions 111 of the semiconductor substrate 110. Therefore, leakage of incident light and leakage of charges from adjacent phase difference pixels 200 can be reduced.

[0101] The structure of the image pickup element 1 other than this is similar to the structure of the image pickup element 1 described in the first embodiment of the present disclosure, and will not be described again here.

[0102] As described above, in the image pickup element 1 according to the second embodiment of the present disclosure, by arranging the separation unit 142 between the two phase difference pixels 200 in the semiconductor substrate 110, it is possible to reduce leakage of incident light, etc., and reduce the difference in the generated image signal. It is possible to further reduce the error of phase difference detection.

[0103] <3. Third embodiment>

[0104] In the image pickup element 1 of the first embodiment described above, a pixel circuit 20 is arranged for each pixel 100 and phase difference pixel 200. On the other hand, the image pickup element 1 according to the third embodiment of the present disclosure is different from the first embodiment described above in that a pixel circuit 20 is shared by a plurality of pixels 100 and the like.

[0105] [Pixel Circuit Structure]

[0106] Figure 7 1 is a circuit diagram showing a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 2 The difference between the pixel 100 and the phase difference pixel 200 described in the figure is that the pixel circuit 20 is shared by a plurality of pixels 100, etc. The pixel 100 will be used as an example to illustrate the circuit configuration. The pixel 100 in the figure includes a photoelectric conversion unit 11 and a charge transfer unit 12, and the pixel circuit 20 is arranged separately. The figure shows an example of a configuration in which the pixel circuit 20 is commonly connected to four pixels 100, etc. (pixels 100a, 100b and 100c, and the phase difference pixel 200a).

[0107] The drains of the charge transfer units 12 of the pixels 100 a , 100 b , and 100 c and the phase difference pixel 200 a are commonly connected to the charge holding unit 21 of the pixel circuit 20 .

[0108] By sequentially inputting ON signals to TRs of the pixels 100a, 100b, 100c and the phase difference pixel 200a, charges generated by the photoelectric conversion unit 11 of the pixel 100a and the like are sequentially transferred to the pixel circuit 20. Based on these transferred charges, image signals can be sequentially generated.

[0109] [Pixel structure]

[0110] Figure 8 is a cross-sectional view showing a configuration example of a pixel according to a third embodiment of the present disclosure. Figure 3 , which is a schematic cross-sectional view showing a configuration example of the pixel 100. Note that in the figure, the characters "a" and "b" attached to the reference numerals correspond to Figure 7 Different pixels 100 (pixels 100a and 100b) are shown. Figure 3 The pixel 100 described in the embodiment of the present invention is different in the following points. The charge holding unit 21 is arranged between the pixel 100 and the like. In addition, a plurality of charge transfer units 12 (charge transfer units 12a and 12b) are commonly connected to the charge holding unit 21. That is, the respective gate electrodes 121a and 121b of the charge transfer units 12a and 12b are arranged close to the n-type semiconductor region 112 of the charge holding unit 21. The n-type semiconductor region 112 of the charge holding unit 21 constitutes a common drain region of the charge transfer units 12a and 12b. Note that the illustration of the pixel circuit 20 other than the charge holding unit 21 has been omitted.

[0111] [Structure of pixel array unit]

[0112] Fig. 9 is a view showing a configuration example of a pixel array unit according to a third embodiment of the present disclosure. Figure 4 Similarly, this figure is a plan view showing a configuration example of the pixel 100 and the phase difference pixel 200 in the pixel array unit 2. Figure 4 The pixel array unit 2 described in is different in that the pixel circuit 20 is arranged in an outer area of ​​the pixel 100 and the like, and is arranged commonly for each of the plurality of pixels 100 .

[0113] The pixel circuits 20 are commonly arranged for adjacent two rows and two columns of pixels 100, etc. The n-type semiconductor region 112 of the charge holding unit 21 of the pixel circuit 20 is arranged in the central portion of these four pixels 100, etc. The gate electrodes 121 of the four pixels 100, etc. are arranged close to the n-type semiconductor region 112 of the charge holding unit 21.

[0114] Likewise, in the figure, the gate electrode 121 is arranged between the common on-chip lens 182 and the on-chip lens 181. As a result, the output difference of the image signals of the two phase difference pixels 200 can be reduced.

[0115] Since the structure of the image pickup element 1 other than this is similar to the structure of the image pickup element 1 described in the first embodiment of the present disclosure, the description thereof will be omitted here.

[0116] As described above, in the image pickup element 1 according to the third embodiment of the present disclosure, the pixel circuit 20 is shared by a plurality of pixels 100 etc. As a result, the configuration of the pixel 100 etc. can be simplified.

[0117] <4. Fourth embodiment>

[0118] In the image pickup element 1 of the third embodiment described above, the photoelectric conversion unit 11 is arranged in the semiconductor substrate 110 of the pixel 100 and the phase difference pixel 200. On the other hand, the image pickup element 1 according to the fourth embodiment of the present disclosure is different from the first embodiment described above in that a photoelectric conversion film configured to perform photoelectric conversion is further arranged.

[0119] [Pixel Circuit Structure]

[0120] Fig.10 1 is a circuit diagram showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. Figure 7 The difference between the pixel 100 described in the figure and the phase difference pixel 200 is that a photoelectric conversion unit is also arranged and a plurality of pixel circuits 20 are shared by a plurality of pixels 100, etc. The circuit configuration will be described using the pixel 100 as an example. The pixel 100 in the figure also includes a photoelectric conversion unit 13 and a switching element 14, and a plurality of pixel circuits 20 are arranged. The figure shows an example of a configuration in which two pixel circuits 20 (pixel circuits 20a and 20b) are commonly connected to four pixels 100, etc. (pixels 100a, 100b, and 100c, and a phase difference pixel 200a).

[0121] The photoelectric conversion unit 13 is a photoelectric conversion unit formed by sandwiching a photoelectric conversion film between a first electrode and a second electrode. In the figure, the photoelectric conversion unit 13 is constructed as a two-terminal element and generates a charge based on photoelectric conversion. In addition, similar to the charge transfer unit 12, the switch element 14 is an element configured to transfer the charge generated by the photoelectric conversion unit 13. The switch element 14 is constructed as a three-terminal element, including an input terminal, an output terminal and a control signal terminal. Similar to the MOS transistor of the charge transfer unit 12, when the control signal is input to the control signal terminal, the input terminal and the output terminal enter a conducting state. As described below, the photoelectric conversion unit 13 and the switch element 14 are integrally constructed in the pixel 100, etc. In the figure, for convenience, the photoelectric conversion unit 13 and the switch element 14 are shown separately. In addition, a power line Vou is also provided in the pixel 100, etc. in the figure. The power line Vou is a power line for providing a bias voltage to the photoelectric conversion unit 13. In addition, the signal line 6 also includes a signal line TR2 that transmits a control signal to the control signal terminal of the switch element 14. Accordingly, for the purpose of distinction, the signal line for transmitting the control signal to the gate of the charge transfer unit 12 is changed to the signal line TR1.

[0122] The drains of the charge transfer units 12 of the pixels 100a, 100b, and 100c and the phase difference pixel 200a are commonly connected to the charge holding unit 21 of the pixel circuit 20a. Further, one end of the photoelectric conversion unit 13 is connected to the power supply line Vou, and the other end is connected to the input terminal of the switch element 14. The control signal terminal of the switch element 14 is connected to the signal line TR2. The output terminals of the switch elements 14 of the pixels 100a, 100b, and 100c and the phase difference pixel 200a are commonly connected to the charge holding unit 21 of the pixel circuit 20b.

[0123] By sequentially inputting an ON signal to TR1 of each of the pixels 100a, 100b, and 100c and the phase difference pixel 200a, the charge generated by the photoelectric conversion unit 11 of the pixel 100a, etc. is sequentially transferred to the pixel circuit 20a, and an image signal is generated. Similarly, by sequentially inputting a control signal to TR2 of each of the pixels 100a, 100b, and 100c and the phase difference pixel 200a, the charge generated by the photoelectric conversion unit 13 of the pixel 100a, etc. is sequentially transferred to the pixel circuit 20b, and an image signal is generated.

[0124] [Pixel structure]

[0125] Fig.11 4 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. Figure 8 Similarly, the figure is a schematic cross-sectional view showing a configuration example of the pixel 100. Note that in the figure, the characters "a", "b", and "c" attached to the reference numerals correspond to the following. Fig.10 Different pixels 100 (pixels 100a, 100b and 100c) are shown. Figure 8 The pixel 100 described in the figure is different in the following points. The charge transfer unit 12 includes a MOS transistor. In addition, a plurality of charge transfer units 12 (charge transfer units 12a and 12b) are commonly connected to the charge holding unit 21a. That is, the n-type semiconductor region 112 of the charge holding unit 21a constitutes a common drain region of the charge transfer units 12a and 12b. The gate electrodes 125a and 125b in the figure correspond to the gates of these charge transfer units 12. The charge holding unit 21a corresponds to Fig.10 The charge holding unit 21 of the pixel circuit 20a described in FIG. 1 is further provided with a photoelectric conversion unit 19 and a through electrode 139 for transferring the charge generated by the photoelectric conversion unit 19. Further, a high refractive index film 151 is provided between the photoelectric conversion unit 19 and the on-chip lens 181.

[0126] The photoelectric conversion unit 19 is provided on the back side of the semiconductor substrate 110. Specifically, the photoelectric conversion unit 19 is provided in the region of the planarization film 144. The photoelectric conversion unit 19 includes a first electrode 163, an insulating film 162, a photoelectric conversion film 164, a second electrode 165, and a charge accumulation electrode 161. The photoelectric conversion unit 19 is formed by stacking the charge accumulation electrode 161, the insulating film 162, the photoelectric conversion film 164, and the second electrode 165. The first electrode 163, the photoelectric conversion film 164, and the second electrode 165 are arranged in common for a plurality of pixels 100, etc., and the charge accumulation electrode 161 and the insulating film 162 are arranged individually in the pixel 100, etc. In addition, the first electrode 163 is connected to the central portion of the photoelectric conversion film 164 arranged in common for a plurality of pixels 100. Note that the insulating film 162 may also be arranged in common for a plurality of pixels 100, etc.

[0127] The photoelectric conversion film 164 is a film including an organic photoelectric conversion film and configured to perform photoelectric conversion of incident light. The photoelectric conversion film 164 may include, for example, an organic photoelectric conversion material containing rhodamine dye, melamine dye, quinacridone, phthalocyanine dye, coumarin dye, or tris-8-hydroxyquinoline Al. In addition, the photoelectric conversion film 164 may be configured to absorb light having a specific wavelength in the incident light to perform photoelectric conversion.

[0128] The second electrode 165 is an electrode arranged adjacent to the photoelectric conversion film 164. The second electrode 165 may include, for example, indium tin oxide (ITO). The insulating film 162 is a film that insulates between the photoelectric conversion film 164 and the charge accumulation electrode 161. The insulating film 162 may include, for example, SiO2. The charge accumulation electrode 161 is an electrode that is stacked on the photoelectric conversion film 164 through the insulating film 162 and applies a voltage to the photoelectric conversion film 164. The charge accumulation electrode 161 may include, for example, ITO. The charge generated by the photoelectric conversion film 164 is output to the first electrode 163.

[0129] Note that the second electrode 165 and the photoelectric conversion film 164 correspond to Fig.10 The photoelectric conversion unit 13 described in FIG. The insulating film 162, the charge accumulation electrode 161, and the first electrode 163 correspond to Fig.10 The switching element 14 described in .

[0130] In addition, the second electrode 165 corresponds to the connection to Fig.10 In addition, the first electrode 163 corresponds to the terminal of the power line Vou (not shown) described in Fig.10 The charge accumulation electrode 161 corresponds to an output terminal of the switching element 14. Further, the charge accumulation electrode 161 corresponds to a control signal terminal of the switching element 14. Note that the charge accumulation electrode 161 and the first electrode 163 are connected to wirings 168 and 169, respectively.

[0131] During exposure of the image pickup element, a control signal of a voltage higher than the voltage of the power supply line Vou is applied to the charge accumulation electrode 161. Then, electrons of the charge generated by the photoelectric conversion of the photoelectric conversion film 164 are attracted to the charge accumulation electrode 161 and accumulated in a region of the photoelectric conversion film 164 close to the charge accumulation electrode 161 via the insulating film 162. Thereafter, when the charge generated by the photoelectric conversion is transferred, a control signal of a voltage lower than the power supply line Vou is applied to the charge accumulation electrode 161. As a result, the charge (electrons) accumulated in the photoelectric conversion film 164 moves to the first electrode 163 and is output from the wiring 169.

[0132] The through electrode 139 is an electrode that penetrates the semiconductor substrate 110. The through electrode 139 is an electrode configured to transfer charges from the back side of the semiconductor substrate 110 to the front side. For example, the through electrode 139 can be formed by embedding a conductive material such as a metal in a through hole formed in the semiconductor substrate 110. The through electrode 139 and the like in the figure connect the wiring 169 of the photoelectric conversion unit 19 to the wiring layer 132 in the wiring area 130. As described above, the charges generated by the photoelectric conversion unit 19 and transferred to the first electrode 163 are transferred to the front side of the semiconductor substrate via the through electrode 139. These transferred charges are further transferred to the n-type semiconductor region 116 through the wiring layer 132 and the contact plug 133. The n-type semiconductor region 116 constitutes Fig.10 The charge holding unit 21b of the pixel circuit 20b described in FIG.

[0133] The high refractive index film 151 is a film having a high refractive index. The photoelectric conversion unit 19 is arranged close to the on-chip lens 181. By arranging this high refractive index film 151, the converging position of the incident light can be made close to the photoelectric conversion unit 19. For example, silicon nitride (SiN) can be used for the high refractive index film 151. Note that the high refractive index film 151 can be omitted.

[0134] Since the photoelectric conversion unit 19 is arranged between the on-chip lens 181 and the semiconductor substrate 110, light having a wavelength not absorbed by the photoelectric conversion unit 19 is photoelectrically converted by the photoelectric conversion unit 11 of the semiconductor substrate 110. For example, a configuration may be adopted in which the photoelectric conversion unit 19 performs photoelectric conversion of visible light, and the photoelectric conversion unit 11 performs photoelectric conversion of infrared light. In addition, for example, a configuration may also be adopted in which the photoelectric conversion unit 19 performs photoelectric conversion of short-wavelength visible light, and the photoelectric conversion unit 11 performs photoelectric conversion of long-wavelength visible light.

[0135] [Structure of pixel array unit]

[0136] Fig.12is a view showing a configuration example of a pixel array unit according to a fourth embodiment of the present disclosure. Figure 4 Similarly, this figure is a plan view showing a configuration example of the pixel 100 and the phase difference pixel 200 in the pixel array unit 2. Figure 4 The pixel array unit 2 described in is different in that the pixel circuits 20a and 20b are arranged in the outer area of ​​the pixel 100 and the like and are arranged commonly for each of the plurality of pixels 100, and a through electrode 139 is also arranged.

[0137] The pixel circuit 20a is commonly arranged for the pixels 100 of two adjacent rows and two columns, etc. The n-type semiconductor region 112 of the charge holding unit 21 of the pixel circuit 20a is arranged in the central part of these four pixels 100, etc. Similarly, the pixel circuit 20b is commonly arranged for the pixels 100 of two adjacent rows and two columns, etc. The through electrode 139 connected to the pixel circuit 20b is arranged in the central part of the four pixels 100, etc.

[0138] In the figure, the through electrode 139 is arranged between the common on-chip lens 182 and the on-chip lens 181. The through electrode 139 corresponds to a structure that is arranged in the semiconductor substrate 110 and does not contribute to photoelectric conversion. By arranging the through electrode 139 in a region different from the region where the common on-chip lens 182 is arranged, the output difference of the image signals of the two phase difference pixels 200 can be reduced.

[0139] Note that the configuration of the pixel 100 etc. is not limited to this example. For example, the photoelectric conversion unit composed of the photoelectric conversion film may be a two-terminal type in which the charge accumulation electrode 161 is omitted. Even in this case, the through electrode 139 is arranged between the common on-chip lens 182 and the on-chip lens 181.

[0140] Since the configuration of the image pickup element 1 other than the above is similar to that of the image pickup element 1 described in the first embodiment of the present disclosure, the description thereof will be omitted.

[0141] As described above, in the image pickup element 1 according to the fourth embodiment of the present disclosure, the through-electrode 139, which is a structure that does not contribute to photoelectric conversion, is arranged between the common on-chip lens 182 and the on-chip lens 181 of the pixel 100. As a result, the difference in the image signal of the phase difference pixel 200 can be reduced, and the error of the phase difference detection of the phase difference pixel 200 can be reduced.

[0142] <5. Fifth embodiment>

[0143] In the image pickup element 1 of the fourth embodiment described above, a photoelectric conversion unit 19 including a photoelectric conversion film is arranged on the back side of the semiconductor substrate 110. On the other hand, the image pickup element 1 according to the fifth embodiment of the present disclosure is different from the fourth embodiment described above in that a color filter is arranged between the on-chip lens and the photoelectric conversion unit 19.

[0144] [Pixel structure]

[0145] Fig.13 : is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. Fig.11 Similarly, this figure is a schematic cross-sectional view showing a configuration example of the pixel 100. The pixel 100 in the figure is Fig.11 The pixel 100 in FIG. 1 is different in that the color filter 150 is arranged between the second electrode 165 and the high refractive index film 151 of the photoelectric conversion unit 19 .

[0146] As the color filter 150, for example, a color filter that shields infrared light or ultraviolet light can be used. This configuration makes it possible to reduce errors due to infrared light or the like in an image pickup element configured to perform visible light imaging.

[0147] The configuration of the image pickup element 1 other than the above is similar to the configuration of the image pickup element 1 described in the fourth embodiment of the present disclosure, and will not be described again.

[0148] As described above, the photoelectric conversion unit 1 of the fifth embodiment of the present disclosure can reduce the error of the image signal of visible light by providing the color filter 150 between the on-chip lens 181 and the photoelectric conversion unit 19 .

[0149] <6. Sixth embodiment>

[0150] In the image pickup element 1 of the fifth embodiment described above, the color filter 150 is provided between the on-chip lens 181 and the photoelectric conversion unit 19. On the other hand, the image pickup element 1 of the sixth embodiment of the present disclosure is different from the fifth embodiment described above in that the color filter is arranged between the photoelectric conversion unit 19 and the semiconductor substrate 110.

[0151] Fig.14 : is a cross-sectional view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. Fig.13 Similarly, this figure is a schematic cross-sectional view showing an example of the configuration of the pixel 100. Fig.13 The pixel 100 in FIG. 1 is different in that the color filter 150 is arranged between the planarization film 144 and the fixed charge film 141 .

[0152] The color filter 150 in the figure is provided between the photoelectric conversion unit 19 and the semiconductor substrate 110, and the light transmitted through the photoelectric conversion unit 19 is incident on the color filter 150 in the figure. Therefore, the color filter can be used to shield the light having a wavelength which is not the target of the photoelectric conversion of the photoelectric conversion unit 11 of the semiconductor substrate 110, among the light not absorbed by the photoelectric conversion unit 19. For example, when the photoelectric conversion unit 19 absorbs green light for photoelectric conversion, the color filter 150 shielding the green light can be used. This configuration makes it possible to reduce the error of the image signal generated by the photoelectric conversion unit 11 of the semiconductor substrate 110.

[0153] The structure of the imaging element 1 other than that described above is similar to that of the imaging element 1 described in the fifth embodiment of the present disclosure, and will not be described again.

[0154] As described above, the photoelectric conversion unit 1 according to the sixth embodiment of the present disclosure can reduce errors of image signals generated in the photoelectric conversion unit 11 of the semiconductor substrate 110 by arranging the color filter 150 between the photoelectric conversion unit 19 and the semiconductor substrate 110 .

[0155] <7. Seventh embodiment>

[0156] In the imaging element 1 of the fourth embodiment, the photoelectric conversion unit 11 is arranged in the semiconductor substrate 110. On the other hand, the imaging element 1 according to the seventh embodiment of the present disclosure is different from the fourth embodiment in that a photoelectric conversion unit arranged on the semiconductor substrate 110 is further provided.

[0157] [Pixel Circuit Structure]

[0158] Fig.15 1 is a circuit diagram showing a configuration example of a pixel according to a seventh embodiment of the present disclosure. Fig.10 The pixel 100 described in the figure is different from the phase difference pixel 200 in that a photoelectric conversion unit is also arranged. The circuit configuration will be described using the pixel 100 as an example. Fig.10 The pixel 100 described in FIG. 1 is different in that a photoelectric conversion unit 15 and a charge transfer unit 16 are further provided, and a pixel circuit 20 c is further provided.

[0159] Similar to the photoelectric conversion unit 11, the photoelectric conversion unit 15 includes a photodiode formed in the semiconductor substrate 110. In addition, the charge transfer unit 16 includes a MOS transistor similar to the charge transfer unit 12. In addition, the signal line 6 also includes a signal line TR3 that transmits a control signal to the gate of the charge transfer unit 16.

[0160] The anode of the photoelectric conversion unit 15 is grounded, and the cathode is connected to the source of the charge transfer unit 16. The gate of the charge transfer unit 16 is connected to the signal line TR3. The drains of the charge transfer units 16 of the pixels 100a, 100b, and 100c and the phase difference pixel 200a are commonly connected to the charge holding unit 21c of the pixel circuit 20c.

[0161] Fig.16 : is a cross-sectional view showing a configuration example of a pixel according to a seventh embodiment of the present disclosure. Fig.11 Similarly, this figure is a schematic diagram of a configuration example of a pixel 10. The pixel 100 in the figure is Fig.11 The pixel 100 described in FIG. 1 is different in that a photoelectric conversion unit 15 , a charge transfer unit 16 , and a color filter 150 are further provided.

[0162] The photoelectric conversion unit 15 is provided near the back surface of the semiconductor substrate 110. Specifically, the n-type semiconductor region 117 constituting the photoelectric conversion unit 15 is formed in a shallow region on the back surface side of the semiconductor substrate 110. On the other hand, the n-type semiconductor region 111 of the photoelectric conversion unit 11 is formed in a deep region of the semiconductor substrate 110. That is, the n-type semiconductor region 111 is arranged near the front surface of the semiconductor substrate 110.

[0163] The n-type semiconductor region 118 arranged in the semiconductor substrate 110 is a semiconductor region constituting the charge holding unit 21 c of the pixel circuit 20 c .

[0164] The charge transfer unit 16 is arranged adjacent to the n-type semiconductor region 117 of the photoelectric conversion unit 15. Figure 3 The charge transfer unit 12 described in FIG. 1 is similarly configured as a vertical transistor. The charge transfer unit 16 includes a gate electrode 126. The charge transfer unit 16 transfers the charge generated by the photoelectric conversion unit 15 arranged on the back side of the semiconductor substrate 110 to the semiconductor region 118 of the charge holding unit 21 arranged on the front side of the semiconductor substrate 110.

[0165] Since the photoelectric conversion unit 19 including the photoelectric conversion film is arranged in the area closest to the on-chip lens 181, it is possible to adopt a structure that performs photoelectric conversion by absorbing light with a short wavelength (for example, blue light). Since the photoelectric conversion unit 15 is arranged in an area shallower than the back side of the semiconductor substrate 110, the photoelectric conversion unit 15 performs photoelectric conversion on light with a relatively short wavelength (for example, green light) in the incident light passing through the photoelectric conversion unit 19. On the other hand, the photoelectric conversion unit 11 is arranged in a deeper area from the back side of the semiconductor substrate 110, and performs photoelectric conversion on light such as red light, infrared light, etc. that reaches the deeper area of ​​the semiconductor substrate 110. As described above, the pixel 100 in the figure can perform photoelectric conversion on incident light within three wavelength ranges and generate an image signal corresponding to each light.

[0166] Note that a color filter that shields ultraviolet light may be used as the color filter 150. Also, when the photoelectric conversion unit 11 performs photoelectric conversion of only red light, a color filter 150 that shields infrared light may be used.

[0167] [Structure of pixel array unit]

[0168] Fig.17 is a view showing a configuration example of a pixel array unit according to a seventh embodiment of the present disclosure. Fig.12 Similarly, this figure is a plan view showing a configuration example of the pixel 100 and the phase difference pixel 200 in the pixel array unit 2. Fig.12 The pixel array unit 2 described in is different in that a pixel circuit 20c is further arranged and a gate electrode 126 is further arranged.

[0169] The pixel circuit 20a in the figure is arranged from Fig.12 The pixel circuit 20a in FIG. 1 is shifted by one pixel. The pixel circuit 20c is arranged at Fig.12 The four gate electrodes 126 are arranged adjacent to the n-type semiconductor region 118 of the charge holding unit of the pixel circuit 20c.

[0170] The charge holding units 21 of the pixel circuits 20 a , 20 b , and 20 c are all commonly connected to the photoelectric conversion units 11 and the like of the four pixels 100 and the like.

[0171] As shown in the figure, a through electrode 139 and a gate electrode 126 (charge transfer unit 16) that do not contribute to photoelectric conversion are arranged in the area between the common on-chip lens 182 and the on-chip lens 181. In addition, the charge holding units 21 of the pixel circuits 20a, 20b, and 20c are all shared and connected by four pixels 100, etc. In this way, the n-type semiconductor region 112, the through electrode 139, and the gate electrode 126 can be respectively arranged at the center of the four pixels 100, etc. As a result, the output difference of the image signals of the two phase difference pixels 200 can be reduced.

[0172] The configuration of the image pickup element 1 other than the above is similar to the configuration of the image pickup element 1 described in the fourth embodiment of the present disclosure, and will not be described again.

[0173] As described above, in the image pickup element 1 according to the seventh embodiment of the present disclosure, the charge transfer unit 16 having the gate electrode 126 and the through-electrode 139, which are structures that do not contribute to photoelectric conversion, are arranged between the common on-chip lens 182 and the on-chip lens 181 of the pixel 100. As a result, the difference in the image signal of the phase difference pixel 200 can be reduced, and the error in the phase difference detection of the phase difference pixel 200 can be reduced.

[0174] Note that the configuration of the phase difference pixel 200 of the second embodiment may be combined with the configurations of the third to seventh embodiments. That is, the partition unit 142 may be disposed in the semiconductor substrate 110 between the phase difference pixels 200 of the third to seventh embodiments.

[0175] <8. Camera application examples>

[0176] The technology according to the present disclosure (the present technology) can be applied to various products. For example, the present technology can be implemented as an imaging element mounted on an imaging device such as a camera.

[0177] Fig.18 1000 is a block diagram showing a schematic configuration example of a camera as an example of an image pickup device to which the present technology can be applied. The camera 1000 in the figure includes a lens 1001, an image pickup element 1002, an image pickup control unit 1003, a lens driving unit 1004, an image processing unit 1005, an operation input unit 1006, a frame memory 1007, a display unit 1008, and a recording unit 1009.

[0178] A lens 1001 is an imaging lens of the camera 1000. The lens 1001 collects light from a subject and allows the light to enter an imaging element 1002 to be described below to form an image of the subject.

[0179] The imaging element 1002 is a semiconductor element that captures light from a subject collected by the lens 1001. The imaging element 1002 generates an analog image signal corresponding to the irradiated light, converts the signal into a digital image signal, and outputs the signal.

[0180] The imaging control unit 1003 controls imaging in the imaging element 1002. The imaging control unit 1003 controls the imaging element 1002 by generating a control signal and outputting it to the imaging element 1002. In addition, the imaging control unit 1003 can perform autofocus in the camera 1000 based on the image signal output from the imaging element 1002. Here, the autofocus is a system that detects the focal position of the lens 1001 and automatically adjusts the focal position. As this autofocus, a method (image plane phase difference autofocus) of detecting the focal position by detecting the image plane phase difference using the phase difference pixels arranged in the imaging element 1002 can also be used. In addition, a detection method (contrast autofocus) of using the position with the highest contrast of the image as the focal position can also be applied. The imaging control unit 1003 adjusts the position of the lens 1001 via the lens driving unit 1004 based on the detected focal position, and performs autofocus. Note that the imaging control unit 1003 may include, for example, a digital signal processor (DSP) equipped with firmware.

[0181] The lens driving unit 1004 drives the lens 1001 based on the control of the imaging control unit 1003. The lens driving unit 1004 can drive the lens 1001 by changing the position of the lens 1001 using a built-in motor.

[0182] The image processing unit 1005 processes the image signal generated by the image pickup element 1002. This processing corresponds to, for example, demosaicing for generating an image signal of insufficient color among image signals corresponding to red, green, and blue for each pixel, noise reduction for removing noise of the image signal, encoding of the image signal, etc. The image processing unit 1005 can be configured by, for example, a microcomputer equipped with firmware.

[0183] The operation input unit 1006 receives an operation input from a user of the camera 1000. As the operation input unit 1006, for example, a button or a touch panel can be used. The operation input received by the operation input unit 1006 is transmitted to the imaging control unit 1003 and the image processing unit 1005. Thereafter, processing according to the operation input is started, such as photographing a subject.

[0184] The frame memory 1007 is a memory for storing frames of an image signal as one screen. The frame memory 1007 is controlled by the image processing unit 1005 and holds frames during image processing.

[0185] The display unit 1008 displays the image processed by the image processing unit 1005. As the display unit 1008, a liquid crystal panel can be used, for example.

[0186] The recording unit 1009 records the image processed by the image processing unit 1005. For example, a memory card or a hard disk can be used as the recording unit 1009.

[0187] The camera to which the present disclosure can be applied has been described above. The present technology can be applied to the imaging element 1002 in the above-mentioned configuration. Specifically, Figure 1 The imaging element 1 described in the claims is applied to the imaging element 1002. By applying the imaging element 1 to the imaging element 1002, it is possible to reduce errors in phase difference detection and prevent image quality degradation of an image when performing autofocus. The camera 1000 is an example of an imaging device described in the claims. The image processing unit 1005 is an example of a processing circuit described in the claims.

[0188] Note that here, a camera has been described as an example, but the technology according to the present disclosure can be applied to, for example, monitoring equipment, etc. In addition, in addition to electronic devices such as cameras, the present disclosure can also be applied to semiconductor devices in the form of semiconductor modules. Specifically, the technology according to the present disclosure can also be applied to a camera module as a semiconductor module, wherein Fig.18 The imaging element 1002 and the imaging control unit 1003 are packaged in one package.

[0189] <9. Application examples of endoscopic surgery systems>

[0190] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0191] Fig.19 is a view showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure can be applied.

[0192] Fig.19 The figure shows a state in which an operator (doctor) 11131 performs surgery on a patient 11132 on a bed 11133 by using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 includes: an endoscope 11100; other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy treatment device 11112; a support arm device 11120 supporting the endoscope 11100; and a cart 11200 on which various devices for endoscopic surgery are installed.

[0193] The endoscope 11100 includes a lens barrel 11101 having a region of a predetermined length from its distal end to be inserted into a body cavity of a patient 11132, and a camera 11102 connected to the proximal end of the lens barrel 11101. In this example, the endoscope 11100 constructed as a so-called rigid endoscope having a rigid lens barrel 11101 is shown, but the endoscope 11100 may be constructed as a so-called flexible endoscope having a flexible lens barrel.

[0194] At the distal end of the lens barrel 11101, an opening equipped with an objective lens is provided. The endoscope 11100 is connected to the light source device 11203, and the light generated by the light source device 11203 is introduced into the distal end of the lens barrel through a light guide extending inside the lens barrel 11101, and irradiated toward an observation target in the body cavity of the patient 11132 via the objective lens. Note that the endoscope 11100 may be a forward-looking endoscope, or may be an oblique-looking endoscope or a side-looking endoscope.

[0195] Inside the camera head 11102, an optical system and an imaging element are provided, and reflected light (observation light) from an observation target is focused on the imaging element by the optical system. The observation light is photoelectrically converted by the imaging element, and an electrical signal corresponding to the observation light is generated, in other words, an image signal corresponding to the observation image is generated. The image signal is transmitted to the camera control unit (CCU) 11201 as RAW data.

[0196] The CCU 11201 is constructed of a central processing unit (CPU), a graphics processing unit (GPU), etc., and integrally controls the actions of the endoscope 11100 and the display device 11202. In addition, the CCU 11201 receives an image signal from the camera 11102, and applies various types of image processing to the image signal to display an image based on the image signal, such as development processing (demosaic processing), etc.

[0197] Under the control of CCU 11201 , display device 11202 displays an image based on an image signal that has undergone image processing by CCU 11201 .

[0198] For example, the light source device 11203 is composed of a light source such as a light emitting diode (LED), and provides the endoscope 11100 with illumination light when capturing an image of a surgical site or the like.

[0199] The input device 11204 is an input interface for the endoscopic surgery system 11000. The user can input various types of information and input instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user inputs instructions to change the imaging conditions of the endoscope 11100 (type of irradiation light, magnification, focal length, etc.).

[0200] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterization, cutting of tissues, sealing of blood vessels, etc. The pneumoperitoneum device 11206 delivers gas into the body cavity through the pneumoperitoneum tube 11111 to inflate the body cavity of the patient 11132, thereby ensuring the field of view of the endoscope 11100 and ensuring the working space of the operator. The recorder 11207 is a device capable of recording various types of information about the operation. The printer 11208 is a device capable of printing various types of information related to the operation in various forms such as text, images, and charts.

[0201] Note that the light source device 11203 that provides the endoscope 11100 with irradiation light for capturing images of the surgical site may include, for example, a white light source composed of an LED, a laser light source, or a combination thereof. In the case where the white light source is composed of a combination of RGB laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the light source device 11203 can adjust the white balance of the captured image. In addition, in this case, it is also possible to capture images corresponding to each RGB in a time-division manner by irradiating the observation target with laser light from each RGB laser source in a time-division manner and controlling the drive of the imaging element of the camera 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter for the imaging element.

[0202] In addition, the drive of the light source device 11203 can be controlled to change the intensity of the light to be output at predetermined intervals. By controlling the drive of the imaging element of the camera 11102 in synchronization with the timing of the light intensity change, images are acquired in a time-division manner, and these images are combined to produce a high dynamic range image without so-called black defects and white overflow.

[0203] In addition, the light source device 11203 can be configured to provide light of a predetermined wavelength band corresponding to special light observation. In special light observation, for example, so-called narrow-band imaging is performed, in which a predetermined tissue is irradiated with a narrow-band light compared to the irradiation light (i.e., white light) during normal observation by utilizing the wavelength dependence of light absorption in body tissue, and predetermined tissues such as blood vessels in the surface layer of the mucosa are imaged with high contrast. Alternatively, in special light observation, fluorescence observation can be performed to acquire an image by using fluorescence generated by irradiating excitation light. In fluorescence observation, body tissue can be irradiated with excitation light and fluorescence from the body tissue can be observed (autofluorescence observation), or reagents such as indocyanine green (ICG) can be locally injected into body tissue, and the body tissue can be irradiated with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescent image, etc. The light source device 11203 can be configured to provide narrow-band light and / or excitation light corresponding to such special light observation.

[0204] Fig. 20 It is shown Fig.19 A block diagram of an example of the functional configuration of the camera 11102 and the CCU 11201 shown in FIG.

[0205] The camera 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera 11102 and the CCU 11201 are bidirectionally connected via a transmission cable 11400.

[0206] The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. Observation light incident from the end of the lens barrel 11101 is guided to the camera 11102 and introduced into the lens unit 11401. The lens unit 11401 is constructed by combining a plurality of lenses including a zoom lens and a focus lens.

[0207] The imaging unit 11402 includes an imaging element. The number of imaging elements included in the imaging unit 11402 may be one (so-called single-board type) or multiple (so-called multi-board type). For example, in the case where the imaging unit 11402 is constructed as a multi-board type, each imaging element may generate image signals corresponding to RGB, respectively, and a color image may be obtained by synthesizing them. Optionally, the imaging unit 11402 may have a pair of imaging elements for respectively acquiring image signals for the right eye and the left eye corresponding to a three-dimensional (3D) display. Performing a 3D display allows the operator 11131 to more accurately grasp the depth of the biological tissue of the surgical site. Note that in the case where the imaging unit 11402 is constructed as a multi-board type, a lens unit 11401 of multiple systems corresponding to each imaging element is also provided.

[0208] In addition, the imaging unit 11402 may not necessarily be disposed in the camera head 11102. For example, the imaging unit 11402 may be disposed in the lens barrel 11101 immediately behind the objective lens.

[0209] The driving unit 11403 is composed of an actuator, and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera control unit 11405. With this configuration, the magnification and focus of the image captured by the camera unit 11402 can be appropriately adjusted.

[0210] The communication unit 11404 is configured by a communication device for exchanging various types of information with the CCU 11201. The communication unit 11404 transmits an image signal obtained from the imaging unit 11402 to the CCU 11201 through the transmission cable 11400 as RAW data.

[0211] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera 11102 from the CCU 11201, and provides it to the camera control unit 11405. The control signal includes information about imaging conditions, such as information specifying a frame rate for capturing an image, information specifying an exposure value during imaging, information specifying a magnification and a focus of a captured image, and the like.

[0212] Note that the above-mentioned imaging conditions such as the frame rate, exposure value, magnification, or focus may be appropriately specified by the user, or may be automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, a so-called automatic exposure (AE) function, an automatic focus (AF) function, and an automatic white balance (AWB) function are installed in the endoscope 11100.

[0213] The camera control unit 11405 controls the driving of the camera 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0214] The communication unit 11411 is constituted by a communication device for exchanging various types of information with the camera 11102. The communication unit 11411 receives an image signal transmitted from the camera 11102 via the transmission cable 11400.

[0215] In addition, the communication unit 11411 transmits a control signal for controlling the driving of the camera 11102 to the camera 11102. The image signal and the control signal may be transmitted through telecommunication, optical communication, or the like.

[0216] The image processing unit 11412 performs various types of image processing on the image signal which is RAW data transmitted from the camera 11102 .

[0217] The control unit 11413 performs various types of control related to photographing the surgical site, etc. through the endoscope 11100 and displaying the captured image obtained by photographing the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera 11102.

[0218] In addition, the control unit 11413 causes the display device 11202 to display a captured image showing a surgical site, etc., based on the image signal processed by the image processing unit 11412. At this time, the control unit 11413 identifies various objects in the captured image by using various image recognition technologies. For example, by detecting the shape, color, etc. of the edge of the object included in the captured image, the control unit 11413 can identify surgical instruments such as forceps, specific living parts, bleeding, fog when using the energy treatment tool 11112, etc. When the display device 11202 is caused to display the captured image, the control unit 11413 can use the recognition result to superimpose and display various types of surgical support information on the image of the surgical site. By superimposing and displaying the surgical support information and presenting it to the operator 11131, the burden of the operator 11131 can be reduced and the operator 11131 can be allowed to reliably perform surgery.

[0219] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electric signal cable corresponding to electric signal communication, an optical fiber corresponding to optical communication, or a composite cable thereof.

[0220] Here, although in the illustrated example, communication is performed by wired communication using the transmission cable 11400, communication between the camera 11102 and the CCU 11201 may be performed by wireless communication.

[0221] An example of an endoscopic surgery system to which the technology of the present disclosure can be applied has been described above. The technology of the present disclosure can be applied to the camera unit 11402 of the camera head 11102 in the above-mentioned structure. Specifically, Figure 1 The imaging element 1 in is applied to the imaging unit 10402. For example, by applying the technology according to the present disclosure to the imaging unit 10402, a clearer image of the surgical site can be obtained, thereby enabling the operator to reliably check the surgical site.

[0222] Note that here, an endoscopic surgery system has been described as an example, but the technology according to the present disclosure can be applied to others, such as a microsurgery system and the like.

[0223] <10. Application examples for mobile objects>

[0224] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be implemented in a device that will be equipped to any mobile body such as a car, an electric car, a hybrid car, a motorcycle, a bicycle, a personal mobile body, an airplane, a drone, a ship, a robot, etc.

[0225] Fig.21is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0226] The vehicle control system 12000 includes a plurality of electronic control units interconnected via a communication network 12001. Fig.21 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside information detection unit 12030, an inside information detection unit 12040, and an integrated control unit 12050. In addition, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown.

[0227] The drive system control unit 12010 controls the operation of the devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 serves as a control device for the following devices: a drive force generating device such as an internal combustion engine or a drive motor that generates the drive force of the vehicle; a drive force transmitting mechanism for transmitting the drive force to the wheels; a steering mechanism that adjusts the steering angle of the vehicle; and a braking device that generates the braking force of the vehicle, etc.

[0228] The body system control unit 12020 controls the operation of the devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 is used as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as a headlight, a reverse light, a brake light, a turn indicator, and a fog light. In this case, the body system control unit 12020 may input radio waves or signals of various switches sent from a portable device instead of a key. The body system control unit 12020 receives these input radio waves or signals and controls the door lock device, power window device, lights, etc. of the vehicle.

[0229] The vehicle exterior information detection unit 12030 detects information about the exterior of the vehicle equipped with the vehicle control system 12000. For example, a camera unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture an image of the exterior of the vehicle and receives the captured image. The vehicle exterior information detection unit 12030 can perform detection processing or distance detection processing on objects such as people, vehicles, obstacles, signs, letters on the road surface, etc. based on the received image.

[0230] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or can output the electrical signal as distance measurement information. In addition, the light received by the imaging unit 12031 can be visible light, or invisible light such as infrared rays.

[0231] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. The in-vehicle information detection unit 12040 is connected to, for example, a driver state detection unit 12041 that detects the state of the driver. The driver state detection unit 12041 may include, for example, a camera that photographs the driver, and based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 may calculate the driver's fatigue level or concentration level, or may determine whether the driver has fallen asleep.

[0232] According to the vehicle internal and external information acquired by the vehicle external information detection unit 12030 or the vehicle internal information detection unit 12040, the microcomputer 12051 can operate the control target value of the driving force generation device, the steering mechanism or the braking device, and output a control instruction to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control to realize the advanced driver assistance system (ADAS) function, which includes collision avoidance or impact reduction of the vehicle, follow-up driving based on vehicle spacing, cruise control, vehicle collision warning, vehicle lane departure warning, etc.

[0233] In addition, by controlling the driving force generating device, steering mechanism, braking device, etc., based on the information around the vehicle obtained by the external information detection unit 12030 or the internal information detection unit 12040, the microcomputer 12051 can perform collaborative control for autonomous driving, for example, without relying on the driver's operation.

[0234] In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle obtained by the vehicle exterior information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of the preceding vehicle or the oncoming vehicle detected by the vehicle exterior information detection unit 12030, and perform cooperative control for anti-glare, such as switching the high beam to the low beam.

[0235] The sound / image output unit 12052 transmits an output signal of at least one of sound or image to an output device capable of visually or auditorily notifying the occupants of the vehicle or the outside of the vehicle of information. Fig.21In the example of FIG. 1 , an audio speaker 12061, a display unit 12062, and a dashboard 12063 are shown as output devices. The display unit 12062 may include, for example, an in-vehicle display or a head-up display.

[0236] Fig. 22 12031 is a diagram showing an example of the installation position of the imaging unit 12031.

[0237] exist Fig. 22 In the figure, as the camera unit 12031, the vehicle 12100 includes camera units 12101, 12102, 12103, 12104 and 12105.

[0238] Camera units 12101, 12102, 12103, 12104 and 12105 are, for example, arranged at the front nose, rearview mirror, rear bumper or rear door, upper part of the windshield, etc. of the vehicle 12100. Camera unit 12101 arranged at the front nose and camera unit 12105 arranged at the upper part of the windshield in the cabin mainly obtain images of the front part of the vehicle 12100. Camera units 12102 and 12103 arranged at the rearview mirror mainly obtain images of the side of the vehicle 12100. Camera unit 12104 arranged at the rear bumper or rear door mainly obtains images of the rear of the vehicle 12100. The front images acquired by camera units 12101 and 12105 are mainly used to detect front vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0239] Notice, Fig. 22 An example of the image capturing range of the camera units 12101 to 12104 is shown. The camera range 12111 indicates the camera range of the camera unit 12101 provided at the front nose, the camera ranges 12112 and 12113 indicate the camera ranges of the camera units 12102 and 12103 provided at the rearview mirrors, respectively, and the camera range 12114 indicates the camera range of the camera unit 12104 provided at the rear bumper or the rear door. For example, by superimposing the image data captured by the camera units 12101 to 12104, a top view image of the vehicle 12100 viewed from above can be obtained.

[0240] 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 including a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0241] For example, based on the distance information obtained from the camera units 12101 to 12104, by acquiring the distance to each three-dimensional object within the camera ranges 12111 to 12114 and the time change of the distance (relative speed with respect to the vehicle 12100), the microcomputer 12051 can extract the closest three-dimensional object that is particularly on the driving route of the vehicle 12100 and is traveling at a predetermined speed (for example, 0 km / h or higher) in the same direction as the vehicle 12100 as the leading vehicle. In addition, the microcomputer 12051 can pre-set the inter-vehicle distance to be ensured with the leading vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. Thus, cooperative control for the purpose of automatic driving, etc., can be performed without relying on the driver's operation.

[0242] For example, based on the distance information obtained from the camera units 12101 to 12104, the microcomputer 12051 can classify the three-dimensional object data about the three-dimensional object into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, electric poles, etc., to extract and use for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles near the vehicle 12100 into obstacles that can be visually recognized by the driver of the vehicle 12100 and obstacles that are difficult to visually recognize. Then, the microcomputer 12051 can determine the collision risk indicating the degree of risk of collision with each obstacle, and when the collision risk value is equal to or greater than the set value and there is a possibility of collision, a warning can be output to the driver through the audio speaker 12061 or the display unit 12062, or forced deceleration or avoidance steering can be performed by the driving system control unit 12010 to perform driving assistance for avoiding collision.

[0243] At least one of the camera units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 may identify a pedestrian by determining whether there is a pedestrian in an image captured by the camera units 12101 to 12104. For example, such identification of a pedestrian is performed by the following steps: a step of extracting feature points in an image captured by the camera units 12101 to 12104 as infrared cameras; and a step of performing pattern matching processing on a series of feature points representing the outline of an object and determining whether the object is a pedestrian. When the microcomputer 12051 determines that there is a pedestrian in the image captured by the camera units 12101 to 12104 and identifies the pedestrian, the sound / image output unit 12052 controls the display unit 12062 to superimpose and display a square outline for emphasizing the identified pedestrian. In addition, the sound / image output unit 12052 may control the display unit 12062 to display an icon representing a pedestrian, etc., at a desired position.

[0244] 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 camera unit 12031 and the like in the above-mentioned configuration. Specifically, Figure 1 The imaging element 1 in the embodiment is applied to the imaging unit 12031 and the like. By applying the technology according to the present disclosure to the imaging unit 12031 and the like, a clearer captured image can be obtained, thereby reducing the fatigue of the driver.

[0245] Finally, the description of each of the above embodiments is an example of the present disclosure, and the present disclosure is not limited to the above embodiments. Therefore, it is needless to say that various modifications can be made according to design, etc. without departing from the technical idea according to the present disclosure, even in addition to the above embodiments.

[0246] In addition, the effects described in this specification are only examples and are not intended to be limiting. In addition, there may be other effects.

[0247] In addition, the drawings in the above-described embodiments are schematic, and the size ratios and the like of the respective units are not necessarily consistent with the actual ones. In addition, naturally, even between the drawings, there are also portions in which their relationship or size ratio may be different from each other.

[0248] Note that the present technology may also have the following configurations.

[0249] (1) An imaging element, comprising:

[0250] A pixel including a photoelectric conversion unit and a charge transfer unit, wherein the photoelectric conversion unit is configured to perform photoelectric conversion according to incident light, and the charge transfer unit is configured to transfer charges generated by the photoelectric conversion;

[0251] a separate on-chip lens arranged for each of the pixels and configured to individually focus the incident light;

[0252] a plurality of phase difference pixels, each of which includes the photoelectric conversion unit and the charge transfer unit, and the phase difference pixels are arranged adjacent to each other to detect a phase difference;

[0253] a common on-chip lens which is commonly arranged for the plurality of phase difference pixels and is configured to commonly converge the incident light; and

[0254] A pixel circuit is formed in a semiconductor substrate and is configured to generate an image signal based on the transferred charge, wherein:

[0255] The charge transfer units of the plurality of phase difference pixels are arranged in a region between the common on-chip lens and the individual on-chip lenses.

[0256] (2) The image pickup element according to (1) above, wherein the pixel circuit is formed on the front surface side of the semiconductor substrate.

[0257] (3) The imaging element according to (2) above, wherein the photoelectric conversion unit performs photoelectric conversion on the incident light incident on a back surface that is a surface formed on the semiconductor substrate and different from the front surface.

[0258] (4) The image pickup element according to (3) above, wherein the charge transfer unit includes a vertical transistor configured to transfer charges in a thickness direction of the semiconductor substrate.

[0259] (5) The image pickup element according to (2) above, wherein the photoelectric conversion unit includes a photoelectric conversion film disposed adjacent to a back surface side of the semiconductor substrate.

[0260] (6) The image pickup element according to (5) above, wherein the charge transfer unit includes a through electrode that penetrates the semiconductor substrate.

[0261] (7) The imaging element according to (5) above, further comprising a color filter that transmits light having a predetermined wavelength among the incident light.

[0262] (8) The image pickup element according to (7) above, wherein the color filter is arranged between the photoelectric conversion film and the individual on-chip lens and the common on-chip lens.

[0263] (9) The image pickup element according to (7) above, wherein the color filter is arranged between the photoelectric conversion film and the semiconductor substrate.

[0264] (10) The image pickup element according to any one of (1) to (9) above, further including a partition unit disposed between the photoelectric conversion units of the phase difference pixels.

[0265] (11) A camera device, comprising:

[0266] a pixel including a photoelectric conversion unit configured to perform photoelectric conversion according to incident light and a charge transfer unit configured to transfer charges generated by the photoelectric conversion;

[0267] a separate on-chip lens arranged for each of the pixels and configured to individually focus the incident light;

[0268] a plurality of phase difference pixels, each of which includes the photoelectric conversion unit and the charge transfer unit, and the phase difference pixels are arranged adjacent to each other to detect a phase difference;

[0269] a common on-chip lens, the common on-chip lens being commonly arranged for the plurality of phase difference pixels and configured to commonly converge the incident light;

[0270] a pixel circuit formed in a semiconductor substrate and configured to generate an image signal based on the transferred charges; and

[0271] A processing circuit configured to process the generated image signal, wherein:

[0272] The charge transfer units of the plurality of phase difference pixels are arranged in a region between the common on-chip lens and the individual on-chip lenses.

[0273] List of reference numerals

[0274] 1. Camera element

[0275] 2 Pixel Array Unit

[0276] 4 columns of signal processing units

[0277] 11,13,15,19 Photoelectric conversion unit

[0278] 12,12a,12b,16 Charge transfer unit

[0279] 14 Switching elements

[0280] 20,20a,20b,20c Pixel circuit

[0281] 21,21a,21b,21c Charge retention unit

[0282] 100,100a,100b,100c pixels

[0283] 110 Semiconductor substrate

[0284] 121, 121a, 121b, 122 to 124, 125a, 125b, 126 gate electrode

[0285] 139 Through electrode

[0286] 142 Separator Unit

[0287] 150 Color Filters

[0288] 151 High refractive index film

[0289] 161 Charge accumulation electrode

[0290] 162 Insulation film

[0291] 163 First Electrode

[0292] 164 Photoelectric conversion film

[0293] 165 Second electrode

[0294] 181 On-chip lens

[0295] 182 Shared on-chip lens

[0296] 200,200a Phase difference pixel

[0297] 1000 Camera

[0298] 1002 Camera Components

[0299] 1005 Image Processing Unit

[0300] 10402,12031,12101 to 12105 Camera unit

Claims

1. An imaging element, comprising: A pixel including a photoelectric conversion unit and a charge transfer unit, wherein the photoelectric conversion unit is configured to perform photoelectric conversion according to incident light, and the charge transfer unit is configured to transfer charges generated by the photoelectric conversion; a separate on-chip lens arranged for each of the pixels and configured to individually focus the incident light; a plurality of phase difference pixels, each of which includes the photoelectric conversion unit and the charge transfer unit, and the phase difference pixels are arranged adjacent to each other to detect a phase difference; a common on-chip lens, the common on-chip lens being commonly arranged for the plurality of phase difference pixels and configured to commonly converge the incident light; and A pixel circuit is formed in a semiconductor substrate and is configured to generate an image signal based on the transferred charge, wherein: The charge transfer units of the plurality of phase difference pixels are arranged in a region between the common on-chip lens and the individual on-chip lenses and not overlapping with the common on-chip lens.

2. The imaging element according to claim 1, wherein: The pixel circuit is formed on the front surface side of the semiconductor substrate.

3. The imaging element according to claim 2, wherein: The photoelectric conversion unit performs photoelectric conversion on the incident light incident on a rear surface that is a surface formed on the semiconductor substrate and different from the front surface.

4. The imaging element according to claim 3, wherein: The charge transfer unit includes a vertical transistor configured to transfer charges in a thickness direction of the semiconductor substrate.

5. The imaging element according to claim 2, wherein: The photoelectric conversion unit includes a photoelectric conversion film arranged adjacent to a back surface side of the semiconductor substrate.

6. The imaging element according to claim 5, wherein: The charge transfer unit includes a through electrode, which is an electrode penetrating the semiconductor substrate. 7 . The image pickup element according to claim 5 , further comprising a color filter that transmits light having a predetermined wavelength among the incident light.

8. The imaging element according to claim 7, wherein: The color filter is arranged between the photoelectric conversion film and the individual on-chip lens and the common on-chip lens.

9. The imaging element according to claim 7, wherein: The color filter is arranged between the photoelectric conversion film and the semiconductor substrate. 10 . The image pickup element according to claim 1 , further comprising a separation unit disposed between the photoelectric conversion units of the phase difference pixels.

11. A camera device, comprising: An imaging element, wherein the imaging element is the imaging element according to any one of claims 1 to 10; as well as A processing circuit is configured to process an image signal generated in the image sensor.

Images