Imaging device and electronic device

Abstract

Provided is an imaging device (1) provided with first and second imaging elements (100) that convert light beams into charges. The first and second imaging elements have a plurality of pixels (300) that are provided inside a semiconductor substrate (10) so as to be adjacent to each other, pixel separation walls (304) that separate the adjacent pixels from each other, and color filters (202) which are provided above the light receiving surface of the semiconductor substrate and which allow transmission of light beams therethrough but at different wavelengths between the first and second imaging elements. The pixel separation wall included in the first imaging element has a slit at the center of the first imaging element when seen from the light receiving surface side. The pixel separation wall included in the second imaging element does not have a slit at the center of the second imaging element when seen from the light receiving surface side.

Description

[Technical field]

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

[0002] In recent years, imaging devices have adopted a method of detecting a phase difference using a pair of adjacent phase difference detection pixels as an autofocus function. Examples of such a method include the imaging elements disclosed in the following Patent Documents 1 to 3. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-201015 A [Patent Document 2] JP 2017-212351 A [Patent Document 3] JP 2015-216186 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the techniques disclosed in Patent Documents 1 and 2, it is difficult to completely prevent the inflow of charges into adjacent phase difference detection pixels, and therefore there is a limit to further improving the accuracy of phase difference detection. In addition, in the technique disclosed in Patent Document 3, although the inflow of charges as described above can be avoided, when light with a long wavelength is incident on the imaging element, the light is likely to be diffusely reflected by the separation wall that separates the pixels, which may cause crosstalk between adjacent pixels and lead to degradation of the captured image.

[0005] Therefore, the present disclosure proposes an imaging device and electronic device that can improve the accuracy of phase difference detection while avoiding degradation of captured images. [Means for solving the problem]

[0006] According to the present disclosure, there is provided an imaging device including first and second imaging elements that each convert light into an electric charge, wherein each of the first and second imaging elements is provided in a semiconductor substrate and has a plurality of adjacent pixels, a pixel separation wall that separates the adjacent pixels, and a color filter that is provided above a light receiving surface of the semiconductor substrate and transmits light having different wavelengths for the first imaging element and the second imaging element, wherein the pixel separation wall of the first imaging element has a slit at the center of the first imaging element when viewed from the light receiving surface side, and the pixel separation wall of the second imaging element does not have a slit at the center of the second imaging element when viewed from the light receiving surface side.

[0007] According to the present disclosure, there is also provided an electronic device including an imaging device including first and second imaging elements that convert light into electric charges, wherein each of the first and second imaging elements is provided in a semiconductor substrate and has a plurality of adjacent pixels, a pixel separation wall that separates the adjacent pixels, and a color filter that is provided above a light receiving surface of the semiconductor substrate and transmits light having different wavelengths for the first imaging element and the second imaging element, wherein the pixel separation wall of the first imaging element has a slit at the center of the first imaging element when viewed from the light receiving surface side, and the pixel separation wall of the second imaging element does not have a slit at the center of the second imaging element when viewed from the light receiving surface side. [Brief description of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram showing an example of a planar configuration of an imaging device 1 according to an embodiment of the present disclosure. [Diagram 2] 1 is an explanatory diagram showing a part of a cross section of an image pickup element 100a according to a comparative example. [Diagram 3] FIG. 2 is an explanatory diagram showing a planar configuration of an image pickup element 100a according to a comparative example. [Figure 4] 1 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to a first embodiment of the present disclosure. [Diagram 5] 1 is an explanatory diagram (part 1) illustrating an example of a cross-sectional configuration of an image sensor 100 according to a modified example of the first embodiment of the present disclosure. [Figure 6] FIG. 2 is an explanatory diagram (part 2) showing an example of the cross-sectional configuration of the image sensor 100 according to a modified example of the first embodiment of the present disclosure. [Figure 7] FIG. 11 is an explanatory diagram (part 3) showing an example of the cross-sectional configuration of the image sensor 100 according to a modified example of the first embodiment of the present disclosure. [Figure 8] 10 is an explanatory diagram showing an example of a planar configuration of an image sensor 100 according to a second embodiment of the present disclosure. FIG. [Figure 9] 11 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to a third embodiment of the present disclosure. FIG. [Figure 10] FIG. 11 is an explanatory diagram (part 1) showing an example of the cross-sectional configuration of an image sensor 100 according to a modified example of the third embodiment of the present disclosure. [Figure 11] FIG. 13 is an explanatory diagram (part 2) showing an example of the cross-sectional configuration of the image sensor 100 according to a modified example of the third embodiment of the present disclosure. [Figure 12] 11 is an explanatory diagram showing an example of the planar configuration of an image sensor 100 according to a fourth embodiment of the present disclosure. FIG. [Figure 13] 11 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to a fifth embodiment of the present disclosure. FIG. [Figure 14] 13 is an explanatory diagram showing an example of a cross-sectional configuration of an image sensor 100 according to a modified example of the fifth embodiment of the present disclosure. FIG. [Figure 15] 13 is an explanatory diagram showing an example of the planar configuration of an image sensor 100 according to a sixth embodiment of the present disclosure. FIG. [Figure 16] 13 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to a seventh embodiment of the present disclosure. FIG. [Figure 17] 13 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to an eighth embodiment of the present disclosure. FIG. [Figure 18] FIG. 2 is an explanatory diagram showing an example of a schematic functional configuration of a camera. [Figure 19] FIG. 2 is a block diagram showing an example of a schematic functional configuration of a smartphone. [Figure 20]1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 21] 2 is a block diagram showing an example of a functional configuration of a camera head and a CCU. FIG. [Figure 22] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 23] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following embodiments, the same components are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0010] In addition, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding different numbers after the same reference numeral. However, if there is no particular need to distinguish between multiple components having substantially the same or similar functional configurations, only the same reference numerals will be used. Also, similar components in different embodiments may be distinguished by adding different alphabets after the same reference numerals. However, if there is no particular need to distinguish between similar components, only the same reference numerals will be used.

[0011] In addition, the drawings referred to in the following description are drawings for explaining and understanding one embodiment of the present disclosure, and for the sake of clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from the actual ones. Furthermore, the imaging device shown in the drawings may be appropriately redesigned in consideration of the following explanation and known technologies. In addition, in the explanation using a cross-sectional view of the imaging device, the up-down direction of the stacked structure of the imaging device corresponds to the relative direction when the light receiving surface from which the light incident on the imaging device enters is on the top, and may differ from the up-down direction according to the actual gravitational acceleration.

[0012] The dimensions expressed in the following description not only mean dimensions defined mathematically or geometrically, but also include dimensions that include allowable differences (errors and distortions) in the operation of the imaging device and the manufacturing process of the imaging device. Furthermore, "substantially the same" used for specific dimensions in the following description does not only mean that they are completely mathematically or geometrically identical, but also includes dimensions that include allowable differences (errors and distortions) in the operation of the imaging device and the manufacturing process of the imaging device.

[0013] Furthermore, in the following description, "electrically connected" means connecting multiple elements directly or indirectly via other elements.

[0014] In the following description, "sharing" refers to mutual use of one other element (for example, an on-chip lens) between different elements (for example, pixels, etc.).

[0015] The explanation will be given in the following order. 1. Overview of the imaging device 2. Schematic configuration of an image sensor according to a comparative example 3. Background of how the present inventor created the embodiment of the present disclosure 4. First embodiment 4.1 Planar configuration 4.2 Cross-sectional configuration 4.3 Variations 5. Second embodiment 6. Third embodiment 6.1 Planar configuration 6.2 Cross-sectional configuration 6.3 Variations 7. Fourth embodiment 8. Fifth embodiment 8.1 Planar configuration 8.2 Cross-sectional configuration 8.3 Variations 9. Sixth embodiment 10. Seventh embodiment 11. Eighth embodiment 12. Summary 13. Camera application example 14. Examples of smartphone applications 15. Application example to endoscopic surgery system 16. Examples of applications to mobile devices 17. Supplementary Information

[0016] <<1. Overview of the imaging device>> First, a schematic configuration of an imaging device 1 according to an embodiment of the present disclosure will be described with reference to FIG. 1. FIG. 1 is an explanatory diagram showing a planar configuration example of an imaging device 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the imaging device 1 according to an embodiment of the present disclosure has a pixel array section (light receiving section) 30 in which a plurality of imaging elements 100 are arranged in a matrix on a semiconductor substrate 10 made of, for example, silicon, and a peripheral circuit section provided to surround the pixel array section 30. Furthermore, the imaging device 1 includes a vertical drive circuit section 32, a column signal processing circuit section 34, a horizontal drive circuit section 36, an output circuit section 38, and a control circuit section 40 as the peripheral circuit section. Each block of the imaging device 1 will be described in detail below.

[0017] (Pixel array section 30) The pixel array section 30 has a plurality of imaging elements 100 arranged two-dimensionally in a matrix along row and column directions on a semiconductor substrate 10. Each imaging element 100 has a photoelectric conversion section (not shown) and a plurality of pixel transistors (e.g., MOS (Metal-Oxide-Semiconductor) transistors) (not shown). In detail, the pixel transistors include, for example, four MOS transistors: a transfer transistor, a selection transistor, a reset transistor, and an amplification transistor. Note that in the pixel array section 30, the plurality of imaging elements 100 are arranged two-dimensionally, for example, by a Bayer array. Here, the Bayer array is an array pattern in which image pickup elements 100 that absorb light having a green wavelength (e.g., wavelengths of 495 nm to 570 nm) and generate electric charges are arranged in a checkerboard pattern, and in the remaining portion, image pickup elements 100 that absorb light having a red wavelength (e.g., wavelengths of 620 nm to 750 nm) and generate electric charges are arranged alternately in each row, and image pickup elements 100 that absorb light having a blue wavelength (e.g., wavelengths of 450 nm to 495 nm) and generate electric charges are arranged alternately in each row. The detailed structure of the image pickup element 100 will be described later.

[0018] (Vertical drive circuit section 32) The vertical drive circuit unit 32 is formed of, for example, a shift register, selects a pixel drive wiring 42, supplies a pulse for driving the image sensor 100 to the selected pixel drive wiring 42, and drives the image sensor 100 row by row. That is, the vertical drive circuit unit 32 selects and scans each image sensor 100 of the pixel array unit 30 row by row in the vertical direction (up and down direction in FIG. 1), and supplies a pixel signal based on a signal charge generated according to the amount of light received by a photoelectric conversion unit (not shown) of each image sensor 100 to a column signal processing circuit unit 34 (described later) through a vertical signal line 44.

[0019] (Column signal processing circuit unit 34) The column signal processing circuit unit 34 is arranged for each column of the image sensor 100, and performs signal processing such as noise removal for each pixel column on pixel signals output from one row of the image sensor 100. For example, the column signal processing circuit unit 34 performs signal processing such as CDS (Correlated Double Sampling) and AD (Analog-Digital) conversion in order to remove fixed pattern noise specific to each pixel.

[0020] (Horizontal drive circuit section 36) The horizontal drive circuit unit 36 ​​is formed, for example, by a shift register, and sequentially outputs horizontal scanning pulses to select each of the above-mentioned column signal processing circuit units 34 in order, and output pixel signals from each of the column signal processing circuit units 34 to the horizontal signal line 46.

[0021] (Output circuit section 38) The output circuit unit 38 processes pixel signals sequentially supplied from each of the column signal processing circuits 34 through the horizontal signal line 46, and outputs the processed signals. The output circuit unit 38 may function as a functional unit that performs buffering, or may perform black level adjustment, column variation correction, various digital signal processing, and other processes. Note that buffering refers to temporarily storing pixel signals to compensate for differences in processing speed and transfer speed when exchanging pixel signals. Furthermore, the input / output terminal 48 is a terminal for exchanging signals with an external device.

[0022] (Control circuit section 40) The control circuit unit 40 receives an input clock and data instructing an operation mode and the like, and outputs data such as internal information of the imaging device 1. That is, the control circuit unit 40 generates clock signals and control signals that serve as a reference for the operation of the vertical drive circuit unit 32, the column signal processing circuit unit 34, the horizontal drive circuit unit 36, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. Then, the control circuit unit 40 outputs the generated clock signals and control signals to the vertical drive circuit unit 32, the column signal processing circuit unit 34, the horizontal drive circuit unit 36, etc.

[0023] <<2. Schematic configuration of an image sensor according to a comparative example>> Meanwhile, the present inventor has been actively studying providing phase difference detection pixels on the entire surface of the pixel array section 30 of the imaging device 1 (all-pixel phase difference detection) in order to further improve the autofocus function while avoiding deterioration of the captured image, that is, to improve the accuracy of phase difference detection. Under these circumstances, it was considered to provide an imaging element 100a that functions as one imaging element during imaging and functions as two phase difference detection pixels during phase difference detection, on the entire surface of the pixel array section 30 (dual photodiode structure).

[0024] Therefore, before describing the details of the imaging element 100 according to the embodiment of the present disclosure, a schematic configuration of an imaging element 100a according to a comparative example that the present inventor first considered will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram showing a part of a cross section of the imaging element 100a according to the comparative example, and corresponds to a cross section obtained by cutting the imaging element 100a along the thickness direction of the semiconductor substrate 10 in detail. Note that, as described above, the comparative example here refers to an imaging element that the present inventor had considered in detail before making the embodiment of the present disclosure.

[0025] A plurality of image pickup elements 100a according to the comparative example are provided adjacent to each other on a semiconductor substrate 10. As shown in FIG. 2, the image pickup element 100a includes an on-chip lens 200, a color filter 202, a light shielding portion 204, a semiconductor substrate 10, and transfer gates 400a and 400b. The image pickup element 100a further includes pixels 300a and 300b each having a photoelectric conversion portion 302 provided in the semiconductor substrate 10, a pixel separation wall 304 separating the pixels 300a and 300b, and an element separation wall 310 surrounding the two pixels 300a and 300b. The stacked structure of the image pickup element 100a according to the comparative example will be described below, and the following description will be given in the order from the upper side (light receiving surface 10a side) to the lower side in FIG. 2.

[0026] As shown in FIG. 2, the imaging element 100a has one on-chip lens 200 that is provided above the light receiving surface 10a of the semiconductor substrate 10 and focuses incident light onto a photoelectric conversion unit 302, which will be described later.

[0027] Then, the incident light collected by the on-chip lens 200 is incident on the photoelectric conversion units 302 of the two pixels 300a and 300b via a color filter 202 provided below the on-chip lens 200. The color filter 202 is any one of a color filter that transmits a red wavelength component, a color filter that transmits a green wavelength component, and a color filter that transmits a blue wavelength component.

[0028] A light-shielding portion 204 is provided on the light-receiving surface 10a of the semiconductor substrate 10 so as to surround the color filter 202. The light-shielding portion 204 is provided between adjacent imaging elements 100a, thereby providing light shielding between the adjacent imaging elements 100a.

[0029] Furthermore, for example, two photoelectric conversion units 302 having a first conductivity type (e.g., N type) impurity are provided for each of the pixels 300a and 300b in the semiconductor substrate 10 of a second conductivity type (e.g., P type). The photoelectric conversion units 302 absorb light having a red wavelength component, a green wavelength component, or a blue wavelength component that is incident via the color filter 202, and generate electric charges.

[0030] In the image sensor 100a, the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b function as two phase difference detection pixels during phase difference detection.

[0031] In detail, the photoelectric conversion unit 302 changes the amount of generated charge, i.e., the sensitivity, depending on the incident angle of light with respect to its own optical axis (axis perpendicular to the light receiving surface). For example, the photoelectric conversion unit 302 has the highest sensitivity when the incident angle is 0 degrees, and furthermore, the sensitivity of the photoelectric conversion unit 302 has a line symmetrical relationship with respect to the incident angle, with the incident angle being the axis of symmetry. Therefore, in the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b, light from the same point is incident at different incident angles, and each generates an amount of charge according to the incident angle, so that a shift (phase difference) occurs in the detected image. That is, the phase difference can be detected by detecting the difference between pixel signals based on the amount of charge generated by the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b. Therefore, such a difference (phase difference) between pixel signals is detected as a differential signal, for example, in a detection section (not shown) of the output circuit section 38, and the defocus amount is calculated based on the detected phase difference, and the imaging lens (not shown) is adjusted (moved), thereby achieving autofocus.

[0032] Furthermore, in the comparative example, the pixels 300a, 300b having the photoelectric conversion unit 302 are physically separated by a pixel separation wall 304. The pixel separation wall 304 is made of RDTI (Rear Deep Trench Isolation). The RDTI is formed by forming a trench that penetrates the semiconductor substrate 10 from the light receiving surface 10a (rear surface) side of the semiconductor substrate 10 along the thickness direction of the semiconductor substrate 10 to the middle of the semiconductor substrate 10, and embedding a material made of an oxide film or a metal film in the trench. In the image sensor 100a, when the pixel signals output from the two pixels 300a, 300b (more specifically, the photoelectric conversion unit 302) are mixed with each other during phase difference detection, if color mixing occurs, the accuracy of the phase difference detection is deteriorated. Therefore, in the image sensor 100a, in order to further improve the accuracy of phase difference detection, the pixel separation wall 304 is required to separate the two pixels 300a, 300b and prevent color mixing.

[0033] As described above, in the image sensor 100a, the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b function as one photoelectric conversion unit 302 of the image sensor 100a during normal imaging.

[0034] Furthermore, an element isolation wall 310 that surrounds the two pixels 300a and 300b of the imaging element 100a and physically separates the adjacent imaging elements 100a is provided within the semiconductor substrate 10. The element isolation wall 310 is made of, for example, RDTI.

[0035] Furthermore, the charges generated in the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b are transferred via transfer gates 400a, 400b provided on a surface 10b located on the opposite side to the light receiving surface 10a of the semiconductor substrate 10. The charges may be stored, for example, in a floating diffusion section (charge storage section) (not shown) provided in a semiconductor region having a first conductivity type (e.g., N type) provided in the semiconductor substrate 10. Furthermore, a plurality of pixel transistors (not shown) for transferring charges and reading out the charges as pixel signals may be provided on the surface 10b of the semiconductor substrate 10.

[0036] <<3. Background of the Invention That Leads to the Invention of the Present Disclosure>> Next, before describing the details of the embodiment of the present disclosure, the background that led the inventor to create the embodiment of the present disclosure will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram showing the planar configuration of an image sensor 100a according to a comparative example, and more specifically, corresponds to a cross section of the image sensor 100a taken along line AA' shown in Fig. 2.

[0037] As described above, in the all-pixel phase difference detection that the present inventor has been studying, in order to improve the accuracy of phase difference detection, it is necessary to suppress mixing of the outputs of the two pixels 300a and 300b during phase difference detection.

[0038] Therefore, in the above-mentioned Patent Document 1, as shown in FIG. 3, between the two pixels 300a, 300b of each image sensor 100a, two protrusions 304 are provided that protrude from the element separation wall 310 along the column direction toward the center of the image sensor 100 and face each other. According to the above-mentioned Patent Document 1, by providing such protrusions 304, it is possible to prevent the charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b from flowing into the other pixel during phase difference detection, and therefore it is possible to avoid mixing of outputs. As a result, according to the above-mentioned Patent Document 1, the accuracy of phase difference detection is improved, and the occurrence of point defects on the captured image due to the variation in charge flow-in can be suppressed.

[0039] In addition, in the above-mentioned Patent Document 2, two separators are provided between two pixels of each image sensor, and serve as potential barriers having different potentials with respect to the charges generated in the photoelectric conversion unit. According to the above-mentioned Patent Document 2, by providing such separators, it is possible to prevent the outputs of the two pixels from being mixed together during phase difference detection, thereby improving the accuracy of phase difference detection.

[0040] Furthermore, in the above Patent Document 3, an insulating layer (not shown) embedded in a substrate is provided between two pixels of each imaging element. According to the above Patent Document 3, by providing such an insulating layer, it is possible to prevent the outputs of the two pixels from being mixed together during phase difference detection, thereby improving the accuracy of phase difference detection.

[0041] However, according to the study by the present inventor, in the techniques disclosed in the above Patent Documents 1 and 2, it is difficult to completely prevent the inflow of electric charges into adjacent pixels, so there is a limit to improving the accuracy of phase difference detection. In addition, in the technique disclosed in the above Patent Document 3, although such inflow of electric charges can be avoided, when light with a long wavelength is incident on an imaging element, the light is likely to be diffusely reflected by an insulating layer provided between two pixels. As a result, in the above Patent Document 3, crosstalk is likely to occur between adjacent imaging elements, leading to deterioration of the captured image.

[0042] In view of this situation, the present inventor has focused on the characteristics of light incident on the image sensor 100 and created an embodiment of the present disclosure that can improve the accuracy of phase difference detection while avoiding degradation of the captured image.

[0043] Specifically, when focusing on the characteristics of light in different wavelength ranges, green light has a short wavelength, and therefore, when such light is incident on an imaging element, it is absorbed by a photoelectric conversion unit near the surface of a semiconductor substrate. Therefore, even if a pixel separation wall is provided between two pixels, the light is unlikely to be diffusely reflected by the pixel separation wall, and crosstalk is unlikely to occur. On the other hand, red light has a long wavelength, and therefore, when such light is incident on an imaging element, it is unlikely to be absorbed by a photoelectric conversion unit near the surface of a semiconductor substrate. Therefore, when a pixel separation wall is provided between two pixels, the light is likely to be diffusely reflected by the pixel separation wall and enter an adjacent imaging element, and crosstalk is likely to occur. Therefore, the present inventor has created an embodiment of the present disclosure by focusing on the characteristics of such light.

[0044] In detail, in the embodiment of the present disclosure created by the present inventor, in an image sensor (first image sensor) 100 that absorbs light having a red wavelength component and generates electric charges, when the image sensor 100 is viewed from the light receiving surface 10a side, a slit 312 is provided near the center of the image sensor 100 in a pixel separation wall 304 that separates two pixels 300a and 300b (see FIG. 4). By providing the slit 312 near the center of the image sensor 100 in this manner, it is possible to prevent light that has entered near the center of the image sensor 100 from being diffusely reflected by the pixel separation wall 304 and entering an adjacent image sensor 100. As a result, in the embodiment of the present disclosure, crosstalk can be avoided, and thus deterioration of captured images can be suppressed.

[0045] In addition, in the embodiment of the present disclosure created by the present inventor, in the imaging element (second imaging element) 100 that absorbs light having a green wavelength component and generates electric charges, it is considered that the diffuse reflection as described above is unlikely to occur, so that when the imaging element 100 is viewed from the light receiving surface 10a side, the pixel separation wall 304 that separates the two pixels 300a and 300b is not provided with the slit 312 (see FIG. 4). The pixel separation wall 304 without the slit 312 can prevent electric charges generated in the photoelectric conversion unit 302 of one of the two pixels 300a and 300b from flowing into the other pixel, so that the separation ratio of the pixels 300a and 300b can be improved. Therefore, in the embodiment of the present disclosure, the accuracy of phase difference detection is improved, and the occurrence of point defects on the captured image due to the variation in the inflow of electric charges can be suppressed.

[0046] That is, according to the embodiment of the present disclosure created by the present inventor, it is possible to improve the accuracy of phase difference detection while avoiding degradation of a captured image. Hereinafter, the details of the embodiment of the present disclosure will be described in order.

[0047] <<4. First embodiment>> <4.1 Planar configuration> First, a planar configuration of the image sensor 100 according to the first embodiment of the present disclosure will be described with reference to Fig. 4. Fig. 4 is an explanatory diagram showing a configuration example of the image sensor 100 according to this embodiment, and in detail, the diagram shown in the upper part of Fig. 4 corresponds to a cross section of the image sensor 100 cut along line AA' shown in Fig. 2, and the diagram shown in the lower part of Fig. 4 corresponds to a cross section of the image sensor 100 cut along line BB' shown in the upper part of Fig. 4.

[0048] As shown in the upper part of FIG. 4, in this embodiment, two adjacent rectangular pixels 300a and 300b of one image sensor 100 are separated by a pixel separation wall 304 formed integrally with an element separation wall 310. Furthermore, in this embodiment, in an image sensor (first image sensor, third image sensor) 100 that absorbs light having red and blue wavelength components to generate electric charges, a slit 312 is provided in the pixel separation wall 304 near the center of the image sensor 100 when the image sensor 100 is viewed from the light receiving surface 10a side. In other words, the element separation wall 310 of the image sensor 100 that absorbs red and blue light has two protrusions 304 that protrude along the column direction toward the center of the image sensor 100 and face each other when the image sensor 100 is viewed from above the light receiving surface 10a. Note that, in this embodiment, the length of the slit 312 along the vertical direction in FIG. 4 is not particularly limited. Furthermore, in this embodiment, the position of the slit 312 is not limited to being at the center of the image sensor 100, and may be shifted from the center of the image sensor 100 by a predetermined distance, for example.

[0049] In this embodiment, in an imaging element (first imaging element, third imaging element) 100 that absorbs red and blue light and generates electric charges, a slit 312 is provided near the center of the imaging element 100, thereby making it possible to prevent light that is incident near the center of the imaging element 100 from being diffusely reflected by the pixel separation wall 304 and entering an adjacent imaging element 100. As a result, in this embodiment, crosstalk can be avoided, and degradation of captured images can be suppressed.

[0050] On the other hand, in this embodiment, in an imaging element (second imaging element) 100 that absorbs light having a green wavelength component and generates electric charge, when the imaging element 100 is viewed from the light receiving surface 10a side, no slit 312 is provided in the pixel separation wall 304.

[0051] In this embodiment, in the imaging element (second imaging element) 100 that absorbs light having a green wavelength component and generates electric charges, the pixel separation wall 304 without the slit 312 can prevent electric charges generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b from flowing into the other pixel, thereby improving the separation ratio of the pixels 300a, 300b. As a result, in this embodiment, the imaging element 100 that absorbs light having a green wavelength component can improve the accuracy of phase difference detection and can suppress the occurrence of point defects on the captured image due to variations in the inflow of electric charges. In particular, since the imaging element 100 that mainly absorbs green light is used for phase difference detection, it is preferable that the imaging element 100 improves the accuracy of phase difference detection.

[0052] That is, in this embodiment, by providing a pixel separation wall 304 having a shape corresponding to the difference in light characteristics due to the difference in wavelength for each image sensor 100, it is possible to improve the accuracy of phase difference detection while avoiding degradation of the captured image.

[0053] In this embodiment, similarly to the comparative example, an element isolation wall 310 is provided that surrounds two pixels 300a, 300b of each imaging element 100 and physically separates adjacent imaging elements 100. Note that, in the upper part of Fig. 4, the element isolation wall 310 and the pixel isolation wall 304 have approximately the same width, but this is not limited to this in this embodiment.

[0054] <4.2 Cross-sectional configuration> Next, a cross-sectional configuration of the imaging element 100 according to the first embodiment of the present disclosure will be described with reference to the diagram shown in the lower part of FIG. 4. As shown in the lower part of FIG. 4, the imaging element 100 according to this embodiment has an on-chip lens 200, a color filter 202, a light-shielding portion (light-shielding film) 204, a semiconductor substrate 10, and transfer gates 400a and 400b, as in the comparative example. Furthermore, in this embodiment, the imaging element 100 has pixels 300a and 300b each having a photoelectric conversion portion 302 provided in the semiconductor substrate 10, a pixel separation wall 304 separating the pixels 300a and 300b, and an element separation wall 310 surrounding the two pixels 300a and 300b in the imaging element 100. The stacked structure of the imaging element 100 according to this embodiment will be described below, and in the following description, the description will be made in the order from the upper side (light receiving surface 10a side) to the lower side in the diagram shown in the lower part of FIG. 4.

[0055] As shown in the lower part of FIG. 4, the imaging element 100 has one on-chip lens 200 that is provided above the light receiving surface 10a of the semiconductor substrate 10 and focuses incident light onto a photoelectric conversion unit 302. As in the comparative example, the imaging element 100 has a structure in which two pixels 300a, 300b are provided for one on-chip lens 200. That is, the on-chip lens 200 is shared by the two pixels 300a, 300b. The on-chip lens 200 can be formed of, for example, a silicon nitride film (SiN) or a resin material such as a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, or a siloxane resin.

[0056] Then, the incident light collected by the on-chip lens 200 is incident on the photoelectric conversion units 302 of the two pixels 300a and 300b through the color filter 202 provided below the on-chip lens 200 and above the light receiving surface 10a. In other words, in the imaging element 100, two pixels 300a and 300b are provided for one stack of the on-chip lens 200 and one color filter 202, as in the comparative example. The color filter 202 is any one of a color filter that transmits a red wavelength component, a color filter that transmits a green wavelength component, and a color filter that transmits a blue wavelength component. For example, the color filter 202 can be formed from a material in which a pigment or a dye is dispersed in a transparent binder such as silicone.

[0057] Further, a light-shielding portion 204 is provided on the light-receiving surface 10a of the semiconductor substrate 10 so as to surround the color filter 202. The light-shielding portion 204 is provided between adjacent image pickup elements 100, thereby suppressing crosstalk between the adjacent image pickup elements 100 and providing light shielding between the adjacent image pickup elements 100 in order to further improve accuracy in phase difference detection. The light-shielding portion 204 can be formed from a metal material including, for example, tungsten (W), aluminum (Al), copper (Cu), titanium (Ti), molybdenum (Mo), nickel (Ni), or the like.

[0058] Furthermore, for example, two photoelectric conversion units 302 having a first conductivity type (e.g., N type) impurity are provided for each of the pixels 300a and 300b in the semiconductor substrate 10 of a second conductivity type (e.g., P type). As described above, the photoelectric conversion unit 302 absorbs light having a red wavelength component, a green wavelength component, or a blue wavelength component that is incident through the color filter 202 to generate electric charges. In this embodiment, similarly to the comparative example, the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b function as a pair of phase difference detection pixels during phase difference detection. That is, in this embodiment, the phase difference can be detected by detecting the difference between pixel signals based on the amount of electric charges generated by the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b. In the above description, the phase difference is detected as the difference between the pixel signals of the photoelectric conversion unit 302 of pixel 300a and the photoelectric conversion unit 302 of pixel 300b. However, this embodiment is not limited to this. For example, the phase difference may be detected as the ratio between the pixel signals of the photoelectric conversion unit 302 of pixel 300a and the photoelectric conversion unit 302 of pixel 300b.

[0059] Furthermore, in this embodiment, as in the comparative example, the two rectangular pixels 300a, 300b are separated from each other by a pixel separation wall 304, which is an RDTI provided so as to penetrate from the light receiving surface 10a to partway through the semiconductor substrate 10 along the thickness direction of the semiconductor substrate 10. As described above, the RDTI is formed by forming a groove portion (trench) (not shown) that penetrates partway through the semiconductor substrate 10 from the light receiving surface 10a (rear surface) side of the semiconductor substrate 10 along the thickness direction of the semiconductor substrate 10, and filling the trench with a material made of an oxide film or a metal film such as a silicon oxide film (SiO), a silicon nitride film, amorphous silicon, polycrystalline silicon, a titanium oxide film (TiO), aluminum, or tungsten.

[0060] In this embodiment, similarly to the comparative example, an element isolation wall 310 is provided in the semiconductor substrate 10 to surround two pixels 300a and 300b of the imaging element 100 and physically isolate adjacent imaging elements 100 from each other. The element isolation wall 310 is an RDTI provided to penetrate from the light receiving surface 10a to the middle of the semiconductor substrate 10. That is, the element isolation wall 310 is made of a groove (trench) (not shown) that penetrates from the light receiving surface 10a (rear surface) side of the semiconductor substrate 10 to the middle of the semiconductor substrate 10 along the thickness direction of the semiconductor substrate 10, and a material that is filled in the trench and is made of an oxide film or a metal film such as a silicon oxide film, a silicon nitride film, an amorphous silicon, a polycrystalline silicon, a titanium oxide film, an aluminum film, or a tungsten film.

[0061] As shown in the lower part of FIG. 4, the pixel isolation wall 304 and the element isolation wall 310 have substantially the same depth from the light receiving surface 10a of the semiconductor substrate 10, but this is not limited to this in the present embodiment.

[0062] Furthermore, in this embodiment, the charges generated in the photoelectric conversion unit 302 of the pixel 300a and the photoelectric conversion unit 302 of the pixel 300b are transferred through the transfer gates 400a and 400b of the transfer transistors (one type of pixel transistor described above) provided on the surface 10b located on the opposite side of the light receiving surface 10a of the semiconductor substrate 10. The transfer gates 400a and 400b can be formed of, for example, a metal film. The charges may be stored in, for example, a floating diffusion section (charge storage section) (not shown) provided in a semiconductor region having a first conductivity type (for example, N type) provided in the semiconductor substrate 10. In this embodiment, the floating diffusion section is not limited to being provided in the semiconductor substrate 10, and may be provided in, for example, another substrate (not shown) stacked on the semiconductor substrate 10.

[0063] Furthermore, a plurality of pixel transistors (not shown) other than the above-mentioned transfer transistors, which are used for reading out charges as pixel signals, etc., may be provided on the surface 10b of the semiconductor substrate 10. Furthermore, in this embodiment, the pixel transistors may be provided on the semiconductor substrate 10, or may be provided on another substrate (not shown) stacked on the semiconductor substrate 10.

[0064] As described above, in this embodiment, in the imaging element (first imaging element, third imaging element) 100 that absorbs red and blue light, when the imaging element 100 is viewed from the light receiving surface 10a side, the slit 312 is provided in the pixel separation wall 304 that separates the two pixels 300a and 300b near the center of the imaging element 100. In this manner, according to this embodiment, in the imaging element 100 that absorbs red and blue light and generates electric charges, it is possible to prevent light that is incident near the center of the imaging element 100 from being diffusely reflected by the pixel separation wall 304 and being incident on an adjacent imaging element 100. As a result, in this embodiment, in the imaging element 100 that absorbs red and blue light, crosstalk can be avoided, and degradation of the captured image can be suppressed.

[0065] Furthermore, in this embodiment, since it is considered that diffuse reflection as described above is unlikely to occur in the imaging element (second imaging element) 100 that absorbs green light, when the imaging element 100 is viewed from the light receiving surface 10a side, the pixel separation wall 304 that separates the two pixels 300a and 300b is not provided with the slit 312. In this way, according to this embodiment, in the imaging element 100 that absorbs light having a green wavelength component and generates charges, the charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a and 300b can be prevented from flowing into the other pixel, so that the separation ratio of the pixels 300a and 300b can be improved. As a result, in this embodiment, the imaging element 100 that absorbs light having a green wavelength component improves the accuracy of phase difference detection, and the occurrence of point defects on the captured image due to variations in charge flow can be suppressed. In particular, since the imaging element 100 that absorbs green light is mainly used during phase difference detection, it is preferable that the accuracy of phase difference detection in the imaging element 100 is improved.

[0066] That is, in this embodiment, by providing a pixel separation wall 304 having a shape corresponding to the difference in light characteristics due to the difference in wavelength for each image sensor 100, it is possible to improve the accuracy of phase difference detection while avoiding degradation of the captured image.

[0067] <4.3 Modifications> This embodiment can be modified as follows. Modifications of this embodiment will be described with reference to Fig. 5 to Fig. 7. Fig. 5 to Fig. 7 are explanatory diagrams showing examples of the cross-sectional configuration of an image sensor 100 according to a modification of this embodiment, and more specifically, correspond to a cross section of the image sensor 100 taken along line BB' or CC' shown in Fig. 4.

[0068] (Variation 1) First, Modification 1 will be described with reference to Fig. 5. As shown in Fig. 5, in this modification 1, the depth of pixel separation wall 304 with respect to light receiving surface 10a may be shallower than the depth of element separation wall 310. Also, in this modification, as shown in Fig. 5, the width of pixel separation wall 304 may be narrower than the width of element separation wall 310. According to this modification 1, by setting the depth and width of pixel separation wall 304 as described above, it is possible to prevent light incident near the center of image sensor 100 from being diffusely reflected by pixel separation wall 304 and entering adjacent image sensor 100, thereby avoiding crosstalk and thereby suppressing deterioration of captured images.

[0069] (Variation 2) Next, Modification 2 will be described with reference to Fig. 6. As shown in Fig. 6, in Modification 2, the depth of pixel separation wall 304 of imager (first imager) 100 absorbing red light with respect to light receiving surface 10a may be deeper than the pixel separation wall 304 of imager (second imager) 100 absorbing green light. Also, in Modification 2, the depth of pixel separation wall 304 of imager (third imager) 100 absorbing blue light with respect to light receiving surface 10a may be shallower than the pixel separation wall 304 of imager (second imager) 100 absorbing green light.

[0070] As described above, the depth of the region of the semiconductor substrate 10 where the light is absorbed with respect to the light receiving surface 10a varies depending on the wavelength of the light. In particular, the longer the wavelength of the light, the deeper the region of the semiconductor substrate 10 that the light reaches. Therefore, for light with a long wavelength, it is preferable to provide the pixel separation wall 304 deeper in order to suppress the occurrence of crosstalk as described above. However, the deeper the pixel separation wall 304 is, the more difficult it becomes to manufacture the image sensor 100, and the higher the possibility of damaging the image sensor 100 during manufacturing. If the image sensor 100 is damaged, there is a risk of dark current being generated.

[0071] In light of the above, in this modification, in the image sensor 100 that absorbs red light having a long wavelength, the depth of the pixel separation wall 304 relative to the light receiving surface 10a is increased to suppress the occurrence of crosstalk. Furthermore, in this modification, in the image sensor 100 that absorbs blue light having a short wavelength, the depth of the pixel separation wall 304 relative to the light receiving surface 10a is decreased to suppress the decrease in yield and the occurrence of dark current.

[0072] (Variation 3) Modification 3 will be described further with reference to Fig. 7. As shown in Fig. 7, the element isolation wall 310 may be provided so as to penetrate the semiconductor substrate 10 from the light receiving surface (rear surface) 10a to the front surface 10b along the thickness direction of the semiconductor substrate 10. According to Modification 3, by providing such element isolation wall 310, it is possible to prevent the charge generated in the imaging element 100 (more specifically, the photoelectric conversion unit 302) from flowing out to other adjacent imaging elements 100, and therefore it is possible to increase the amount of charge that can be stored in the imaging element 100.

[0073] <<5. Second embodiment>> Incidentally, blue light, which has a wavelength shorter than that of red light, is considered to be less likely to be diffusely reflected by the pixel separation wall 304 than red light. Therefore, in an imaging element (third imaging element) 100 that absorbs light having a blue wavelength component and generates electric charges, the pixel separation wall 304 may not be provided with the slits 312 when the imaging element 100 is viewed from the light receiving surface 10a side. Hereinafter, such a second embodiment of the present disclosure will be described with reference to FIG. 8. FIG. 8 is an explanatory diagram showing an example of the planar configuration of the imaging element 100 according to this embodiment, and in detail corresponds to a cross section of the imaging element 100 cut along the line AA' shown in FIG. 2.

[0074] 8, in this embodiment, in an image sensor (third image sensor) 100 that absorbs blue light, when the image sensor 100 is viewed from the light receiving surface 10a side, the pixel separation wall 304 is not provided with a slit 312. By doing so in this embodiment, in the image sensor 100 that absorbs blue light, it is possible to prevent electric charges generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b from flowing into the other pixel, thereby improving the accuracy (separation ratio) of phase difference detection.

[0075] <<6. Third embodiment>> In an embodiment of the present disclosure, imaging elements 100 absorbing light of the same color may be arranged in 2×2 array units on a semiconductor substrate 10. A third embodiment of the present disclosure arranged in this manner will now be described with reference to FIG. 9. FIG. 9 is an explanatory diagram showing an example of the configuration of an imaging element 100 according to this embodiment. In detail, the diagram shown in the upper part of FIG. 9 corresponds to a cross section of the imaging element 100 cut along line AA′ shown in FIG. 2, and the diagram shown in the lower part of FIG. 9 corresponds to a cross section of the imaging element 100 cut along line DD′ shown in the upper part of FIG. 9.

[0076] <6.1 Planar configuration> 9, in this embodiment, a plurality of image pickup elements 100 absorbing light of the same color are arranged in a 2×2 array along the row and column directions, with four such image pickup elements 100 constituting one array unit. In this embodiment, the array units absorbing red, green, and blue light, respectively, are two-dimensionally arranged in a matrix on the semiconductor substrate 10.

[0077] Also in this embodiment, similarly to the first embodiment, in an imaging element (first imaging element, third imaging element) 100 that absorbs red and blue light, a slit 312 is provided in a pixel separation wall 304 near the center of the imaging element 100 when the imaging element 100 is viewed from the light receiving surface 10a side. Furthermore, also in this embodiment, similarly to the first embodiment, in an imaging element (second imaging element) 100 that absorbs green light, a slit 312 is not provided in a pixel separation wall 304 when the imaging element 100 is viewed from the light receiving surface 10a side.

[0078] <6.2 Cross-sectional configuration> The cross-sectional configuration of the image sensor 100 in this embodiment is shown in the lower part of FIG. 9, but since this cross-sectional configuration is common to the first cross-sectional configuration described above, a detailed description thereof will be omitted here.

[0079] <6.3 Modifications> This embodiment can be modified as follows. A modified example of this embodiment will be described with reference to Fig. 10 and Fig. 11. Fig. 10 and Fig. 11 are explanatory diagrams showing an example of the cross-sectional configuration of an image sensor 100 according to a modified example of this embodiment, and more specifically, correspond to a cross section of the image sensor 100 taken along line DD' shown in Fig. 9.

[0080] (Variation 1) First, Modification 1 will be described with reference to Fig. 10. As shown in Fig. 10, in Modification 1, the depth of pixel separation wall 304 with respect to light receiving surface 10a may be shallower than the depth of element separation wall 310. According to Modification 1, by setting the depth of pixel separation wall 304 as described above, it is possible to prevent light incident near the center of image sensor 100 from being diffusely reflected by pixel separation wall 304 and entering adjacent image sensor 100, thereby preventing crosstalk and thereby preventing degradation of captured images.

[0081] In this modification, similarly to the first and second modifications of the first embodiment, the width of the pixel isolation wall 304 may be made narrower than the width of the element isolation wall 310, or the depth of the pixel isolation wall 304 with respect to the light receiving surface 10a may be changed depending on the wavelength of the light to be absorbed.

[0082] (Variation 2) 11, the element isolation wall 310 may be provided so as to penetrate the semiconductor substrate 10 from the light receiving surface (rear surface) 10a to the front surface 10b along the thickness direction of the semiconductor substrate 10. According to the present modification example 2, by providing such an element isolation wall 310, it is possible to prevent the charge generated in the imaging element 100 from flowing out to another adjacent imaging element 100, and therefore it is possible to increase the amount of charge that can be stored in the imaging element 100.

[0083] <<7. Fourth embodiment>> It is possible to apply the above-mentioned second embodiment to the above-mentioned third embodiment. That is, in an image sensor (third image sensor) 100 that absorbs light having a blue wavelength component, when the image sensor 100 is viewed from the light receiving surface 10a side, the slit 312 may not be provided in the pixel separation wall 304. Hereinafter, such a fourth embodiment of the present disclosure will be described with reference to FIG. 12. FIG. 12 is an explanatory diagram showing an example of the planar configuration of the image sensor 100 according to this embodiment, and in detail corresponds to a cross section of the image sensor 100 cut along the line AA' shown in FIG. 2.

[0084] 12, in this embodiment, in an image sensor (third image sensor) 100 that absorbs blue light, when the image sensor 100 is viewed from the light receiving surface 10a side, no slit 312 is provided in the pixel separation wall 304. By doing so in this embodiment, in the image sensor 100 that absorbs blue light, it is possible to prevent electric charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b from flowing into the other pixel, thereby improving the accuracy (separation ratio) of phase difference detection.

[0085] <<8. Fifth embodiment>> In an embodiment of the present disclosure, one image sensor 100 may be configured to have four pixels 300a to 300d. A fifth embodiment of the present disclosure in which the pixels are arranged in this manner will be described with reference to Fig. 13. Fig. 13 is an explanatory diagram showing an example of the configuration of the image sensor 100 according to this embodiment. In detail, the diagram shown in the upper part of Fig. 13 corresponds to a cross section of the image sensor 100 cut along line AA' shown in Fig. 2, and the diagram shown in the lower part of Fig. 13 corresponds to a cross section of the image sensor 100 cut along line EE' shown in the upper part of Fig. 13.

[0086] <8.1 Planar configuration> 13, in this embodiment, one imaging element 100 has four pixels 300a to 300d, which are separated into twos along the row and column directions by pixel separation walls 304. With this structure, a phase difference in the column direction can be detected by individually reading out the amount of charge generated in the pixels 300 arranged along the column direction in the figure, and a phase difference in the row direction can be detected by individually reading out the amount of charge generated in the pixels 300 arranged along the row direction in the figure.

[0087] In this embodiment, similarly to the first embodiment, in an imaging element (first imaging element, third imaging element) 100 that absorbs red and blue light, when the imaging element 100 is viewed from the light receiving surface 10a side, the slit 312 is provided in the pixel separation wall 304 near the center of the imaging element 100, that is, at the centers of the four pixels 300a to 300d. Furthermore, in this embodiment, similarly to the first embodiment, in an imaging element (second imaging element) 100 that absorbs green light, when the imaging element 100 is viewed from the light receiving surface 10a side, the slit 312 is not provided in the pixel separation wall 304, that is, at the centers of the four pixels 300a to 300d. Note that the dashed lines in the upper diagram of FIG. 13 indicate the on-chip lens 200, and in this embodiment, one imaging element 100 has one on-chip lens 200.

[0088] <8.2 Cross-sectional configuration> The cross-sectional configuration of the image sensor 100 in this embodiment is shown in the lower part of FIG. 13, but since this cross-sectional configuration is common to the first cross-sectional configuration described above, a detailed description thereof will be omitted here.

[0089] In this embodiment, the image sensor 100 is not limited to having four pixels 300a to 300d, but may have, for example, eight pixels 300, and is not particularly limited.

[0090] Also in this embodiment, similarly to the first and second variants of the first embodiment, the width of the pixel isolation wall 304 may be made narrower than the width of the element isolation wall 310, or the depth of the pixel isolation wall 304 with respect to the light receiving surface 10a may be changed depending on the wavelength of the light to be absorbed.

[0091] <8.3 Modifications> This embodiment can be modified as follows. A modified example of this embodiment will be described with reference to Fig. 14. Fig. 14 is an explanatory diagram showing an example of the cross-sectional configuration of an image sensor 100 according to a modified example of this embodiment, and corresponds to a cross section of the image sensor 100 taken along line EE' shown in Fig. 13.

[0092] 14, the element isolation wall 310 may be provided so as to penetrate the semiconductor substrate 10 from the light receiving surface (rear surface) 10a to the front surface 10b along the thickness direction of the semiconductor substrate 10. According to this modification, by providing such an element isolation wall 310, it is possible to prevent the charge generated in the imaging element 100 from flowing out to another adjacent imaging element 100, and therefore it is possible to increase the amount of charge that can be stored in the imaging element 100.

[0093] <<9. Sixth embodiment>> The second embodiment described above can also be applied to the fifth embodiment described above. That is, in an image sensor (third image sensor) 100 that absorbs light having a blue wavelength component, the pixel separation wall 304 does not need to be provided with the slit 312 when the image sensor 100 is viewed from the light receiving surface 10a side. Hereinafter, such a sixth embodiment of the present disclosure will be described with reference to FIG. 15. FIG. 15 is an explanatory diagram showing an example of the planar configuration of the image sensor 100 according to this embodiment, and in detail corresponds to a cross section of the image sensor 100 cut along the line AA' shown in FIG. 2.

[0094] 15, in this embodiment, in an image sensor (third image sensor) 100 that absorbs blue light, when the image sensor 100 is viewed from the light receiving surface 10a side, no slit 312 is provided in the pixel separation wall 304. By doing so in this embodiment, in the image sensor 100 that absorbs blue light, it is possible to prevent electric charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b from flowing into the other pixel, thereby improving the accuracy (separation ratio) of phase difference detection.

[0095] <<10. Seventh embodiment>> Hereinafter, the seventh embodiment of the present disclosure will be described with reference to Fig. 16. Fig. 16 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to the seventh embodiment of the present disclosure.

[0096] 16, the angle of incidence θ of light (indicated by an arrow in FIG. 16) incident on the pixel array section (light receiving section) 30 is close to 0 degrees in the central region of the pixel array section 30, and becomes larger toward the outer periphery of the pixel array section 30. As the angle of incidence θ becomes larger, the light is more likely to be reflected by the surface (side surface) of the pixel separation wall 304 perpendicular to the light receiving surface 10a, increasing the possibility of crosstalk occurring.

[0097] Therefore, in this embodiment, as shown in FIG. 16, in the imaging element 100 in the central region of the pixel array unit 30 where crosstalk is unlikely to occur by the above-mentioned mechanism, the depth of the pixel separation wall 304 relative to the light receiving surface 10a is made shallow. Furthermore, in this embodiment, in the imaging element 100 in the peripheral region of the pixel array unit 30 where crosstalk is likely to occur by the above-mentioned mechanism, the depth of the pixel separation wall 304 is made deep. In other words, in this embodiment, the depth of the pixel separation wall 304 relative to the light receiving surface 10a in the imaging element 100 in the central region is shallower than the depth of the pixel separation wall 304 in the imaging element 100 in the peripheral region. In this way, according to this embodiment, in the imaging element 100 in the peripheral region where the angle θ of incidence is large, the occurrence of crosstalk due to reflection of light by the surface of the pixel separation wall 304 perpendicular to the light receiving surface 10a can be suppressed. Furthermore, according to this embodiment, in the imaging element 100 in the central region where crosstalk is unlikely to occur by the same mechanism, the depth of the pixel separation wall 304 is made shallow, thereby suppressing a decrease in yield and the occurrence of dark current.

[0098] <<11. Eighth embodiment>> Hereinafter, the seventh embodiment of the present disclosure will be described with reference to Fig. 17. Fig. 17 is an explanatory diagram showing an example of the configuration of an image sensor 100 according to an eighth embodiment of the present disclosure.

[0099] As described above, the angle of incidence θ of light (indicated by an arrow in FIG. 17) incident on the pixel array section (light receiving section) 30 is close to 0 degrees in the central region of the pixel array section 30, and becomes larger toward the outer periphery of the pixel array section 30. As the angle of incidence θ becomes smaller, the light is more likely to be reflected by the surface (upper surface) of the pixel separation wall 304 parallel to the light receiving surface 10a, increasing the possibility of crosstalk occurring.

[0100] Therefore, in this embodiment, as shown in FIG. 17, in the imaging element 100 in the central region of the pixel array section 30, where crosstalk is highly likely to occur due to the mechanism described above, the width of the pixel separation wall 304 is narrowed. Furthermore, in this embodiment, in the imaging element 100 in the peripheral region of the pixel array section 30, where crosstalk is less likely to occur due to the mechanism described above, the width of the pixel separation wall 304 is widened. In other words, in this embodiment, the width of the pixel separation wall 304 in the imaging element 100 in the central region is narrower than the width of the pixel separation wall 304 in the imaging element 100 in the peripheral region. In this way, according to this embodiment, in the imaging element 100 in the central region, where the angle θ of incidence is small, the occurrence of crosstalk caused by light being reflected by the surface (upper surface) of the pixel separation wall 304 parallel to the light receiving surface 10a can be suppressed. Furthermore, according to this embodiment, in the image sensor 100 in the peripheral region where crosstalk is unlikely to occur by a similar mechanism, the charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a, 300b is prevented from flowing into the other pixel, thereby improving the accuracy (separation ratio) of phase difference detection.

[0101] <<12. Summary>> As described above, in each embodiment of the present disclosure, in an image sensor (first image sensor) 100 that absorbs red light, when the image sensor 100 is viewed from the light receiving surface 10a side, a slit 312 is provided in the pixel separation wall 304 that separates two pixels 300a and 300b near the center of the image sensor 100. In this manner, according to these embodiments, in an image sensor 100 that absorbs red light and generates electric charges, it is possible to prevent light that is incident near the center of the image sensor 100 from being diffusely reflected by the pixel separation wall 304 and being incident on an adjacent image sensor 100. As a result, in these embodiments, in an image sensor 100 that absorbs red and blue light, crosstalk can be avoided, and degradation of captured images can be suppressed.

[0102] Furthermore, in each embodiment of the present disclosure, in the imaging element (second imaging element) 100 that absorbs green light, it is considered that the diffuse reflection described above is unlikely to occur, so when the imaging element 100 is viewed from the light receiving surface 10a side, the pixel separation wall 304 that separates the two pixels 300a and 300b is not provided with the slit 312. In this way, according to these embodiments, in the imaging element 100 that absorbs light having a green wavelength component and generates charges, the charge generated in the photoelectric conversion unit 302 of one of the two pixels 300a and 300b can be prevented from flowing into the other pixel, so that the separation ratio of the pixels 300a and 300b can be improved. As a result, in these embodiments, in the imaging element 100 that absorbs light having a green wavelength component, the accuracy of phase difference detection is improved, and the occurrence of point defects in the captured image due to variations in charge inflow can be suppressed.

[0103] That is, in each embodiment of the present disclosure, by providing a pixel separation wall 304 having a shape corresponding to the difference in light characteristics due to the difference in wavelength for each image sensor 100, it is possible to improve the accuracy of phase difference detection while avoiding degradation of the captured image.

[0104] In the above-described embodiment of the present disclosure, a case has been described in which the present disclosure is applied to a back-illuminated CMOS image sensor structure; however, the embodiment of the present disclosure is not limited to this and may be applied to other structures.

[0105] In the above-described embodiment of the present disclosure, the imaging element 100 is described in which the first conductivity type is N-type, the second conductivity type is P-type, and electrons are used as signal charges, but the embodiment of the present disclosure is not limited to such an example. For example, this embodiment can be applied to an imaging element 100 in which the first conductivity type is P-type, the second conductivity type is N-type, and holes are used as signal charges.

[0106] In the above-described embodiment of the present disclosure, the semiconductor substrate 10 does not necessarily have to be a silicon substrate, but may be another substrate (for example, an SOI (Silicon On Insulator) substrate, a SiGe substrate, etc.). The semiconductor substrate 10 may be such a substrate on which a semiconductor structure or the like is formed.

[0107] Furthermore, the imaging device 1 according to the embodiment of the present disclosure is not limited to an imaging device that detects the distribution of the amount of incident visible light and captures it as an image. For example, the present embodiment can be applied to an imaging device that captures the distribution of the amount of incident infrared rays, X-rays, particles, etc. as an image, or an imaging device (physical quantity distribution detection device) such as a fingerprint detection sensor that detects the distribution of other physical quantities such as pressure and capacitance and captures them as an image.

[0108] Moreover, the imaging device 1 according to the embodiment of the present disclosure can be manufactured using methods, devices, and conditions used in the manufacture of general semiconductor devices. That is, the imaging device 1 according to the present embodiment can be manufactured using existing semiconductor device manufacturing processes.

[0109] Examples of the above-mentioned methods include physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD). Examples of the PVD methods include vacuum deposition, electron beam (EB) deposition, various sputtering methods (magnetron sputtering, radio frequency (RF)-direct current (DC) combined bias sputtering, electron cyclotron resonance (ECR) sputtering, facing target sputtering, high frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE), and laser transfer. Examples of the CVD methods include plasma CVD, thermal CVD, metal organic (MO) CVD, and photo CVD. Further, other methods include electrolytic plating, electroless plating, spin coating, immersion, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, stamping, spraying, and various coating methods such as air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calendar coater. Further, patterning methods include chemical etching such as shadow mask, laser transfer, and photolithography, and physical etching using ultraviolet light, laser, and the like. In addition, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0110] <<13. Camera application example>> The technology according to the present disclosure (the present technology) can be further applied to various products. For example, the technology according to the present disclosure may be applied to a camera or the like. Then, with reference to FIG. 18, a configuration example of a camera 700 as an electronic device to which the present technology is applied will be described. FIG. 18 is an explanatory diagram showing an example of a schematic functional configuration of a camera 700 to which the technology according to the present disclosure (the present technology) can be applied.

[0111] As shown in FIG. 18, the camera 700 includes an imaging device 702, an optical lens 710, a shutter mechanism 712, a drive circuit unit 714, and a signal processing circuit unit 716. The optical lens 710 focuses image light (incident light) from a subject on the imaging surface of the imaging device 702. As a result, signal charges are accumulated in the imaging element 100 of the imaging device 702 for a certain period of time. The shutter mechanism 712 controls the light irradiation period and light blocking period of the imaging device 702 by opening and closing. The drive circuit unit 714 supplies drive signals to the imaging device 702 for controlling the signal transfer operation and the shutter operation of the shutter mechanism 712. That is, the imaging device 702 transfers signals based on the drive signal (timing signal) supplied from the drive circuit unit 714. The signal processing circuit unit 716 performs various signal processes. For example, the signal processing circuit unit 716 outputs the processed video signal to a storage medium such as a memory (not shown), or to a display unit (not shown).

[0112] <<14. Smartphone Application Examples>> The technology according to the present disclosure (the present technology) can be further applied to various products. For example, the technology according to the present disclosure may be applied to a smartphone or the like. Therefore, with reference to FIG. 19, a configuration example of a smartphone 900 as an electronic device to which the present technology is applied will be described. FIG. 19 is a block diagram showing an example of a schematic functional configuration of a smartphone 900 to which the technology according to the present disclosure (the present technology) can be applied.

[0113] 19, the smartphone 900 includes a central processing unit (CPU) 901, a read only memory (ROM) 902, and a random access memory (RAM) 903. The smartphone 900 also includes a storage device 904, a communication module 905, and a sensor module 907. The smartphone 900 also includes an imaging device 909, a display device 910, a speaker 911, a microphone 912, an input device 913, and a bus 914. The smartphone 900 may also include a processing circuit such as a digital signal processor (DSP) instead of or in addition to the CPU 901.

[0114] The CPU 901 functions as an arithmetic processing device and a control device, and controls the overall operation or a part of the operation in the smartphone 900 according to various programs recorded in the ROM 902, the RAM 903, the storage device 904, or the like. The ROM 902 stores programs and arithmetic parameters used by the CPU 901. The RAM 903 temporarily stores programs used in the execution of the CPU 901 and parameters that change appropriately in the execution. The CPU 901, the ROM 902, and the RAM 903 are connected to each other by a bus 914. The storage device 904 is a data storage device configured as an example of a storage unit of the smartphone 900. The storage device 904 is configured, for example, by a magnetic storage device such as an HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or the like. The storage device 904 stores programs and various data executed by the CPU 901, and various data acquired from the outside.

[0115] The communication module 905 is, for example, a communication interface configured with a communication device for connecting to a communication network 906. The communication module 905 may be, for example, a communication card for a wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), or WUSB (Wireless USB). The communication module 905 may also be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various communications. The communication module 905 transmits and receives signals, for example, between the Internet and other communication devices using a predetermined protocol such as TCP / IP. The communication network 906 connected to the communication module 905 is a network connected by wire or wirelessly, for example, the Internet, a home LAN, infrared communication, or satellite communication.

[0116] The sensor module 907 includes various sensors such as a motion sensor (e.g., an acceleration sensor, a gyro sensor, a geomagnetic sensor, etc.), a biometric information sensor (e.g., a pulse sensor, a blood pressure sensor, a fingerprint sensor, etc.), or a position sensor (e.g., a GNSS (Global Navigation Satellite System) receiver, etc.).

[0117] The imaging device 909 is provided on the front surface of the smartphone 900, and can capture an image of an object located on the back side or front side of the smartphone 900. In detail, the imaging device 909 can be configured to include an imaging element (not shown) such as a CMOS (Complementary MOS) image sensor to which the technology according to the present disclosure (the present technology) can be applied, and a signal processing circuit (not shown) that performs imaging signal processing on a signal photoelectrically converted by the imaging element. Furthermore, the imaging device 909 can further include an optical system mechanism (not shown) configured of an imaging lens, an aperture mechanism, a zoom lens, a focus lens, and the like, and a drive system mechanism (not shown) that controls the operation of the optical system mechanism. The imaging element collects incident light from an object as an optical image, and the signal processing circuit photoelectrically converts the formed optical image in pixel units, reads out the signal of each pixel as an imaging signal, and performs image processing to obtain an imaged image.

[0118] The display device 910 is provided on the surface of the smartphone 900, and can be, for example, a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. The display device 910 can display an operation screen, a captured image acquired by the imaging device 909 described above, and the like.

[0119] The speaker 911 can output, for example, telephone call audio, audio accompanying the video content displayed by the display device 910 described above, and the like, to the user.

[0120] The microphone 912 can collect, for example, the user's call voice, voice including a command to activate a function of the smartphone 900, and voice from the surrounding environment of the smartphone 900.

[0121] The input device 913 is a device operated by a user, such as a button, a keyboard, a touch panel, a mouse, etc. The input device 913 includes an input control circuit that generates an input signal based on information input by the user and outputs the signal to the CPU 901. By operating the input device 913, the user can input various data to the smartphone 900 and instruct the smartphone 900 to perform processing operations.

[0122] The above shows an example of the configuration of the smartphone 900. Each of the above components may be configured using general-purpose materials, or may be configured using hardware specialized for the function of each component. Such a configuration may be appropriately changed depending on the technical level at the time of implementation.

[0123] <<15. Application example to endoscopic surgery system>> The technology according to the present disclosure (the present technology) can be further applied to various products. For example, the technology according to the present disclosure may be applied to an endoscopic surgery system.

[0124] FIG. 20 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0125] 20 shows a state in which an operator (doctor) 11131 is performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0126] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may be configured as a so-called flexible scope having a flexible lens barrel.

[0127] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0128] An optical system and an image sensor are provided inside the camera head 11102, and reflected light (observation light) from an observation target is collected on the image sensor by the optical system. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 11201 as RAW data.

[0129] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various types of image processing on the image signal, such as development processing (demosaic processing), for displaying an image based on the image signal.

[0130] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0131] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing an operation site or the like.

[0132] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiated light, magnification, focal length, etc.) of the endoscope 11100.

[0133] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 sends gas into the body cavity of the patient 11132 via the insufflation tube 11111 to inflate the body cavity for the purpose of securing the field of view of the endoscope 11100 and securing the working space of the surgeon. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0134] The light source device 11203 that supplies irradiation light to the endoscope 11100 when photographing the surgical site can be composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the white balance of the captured image can be adjusted in the light source device 11203. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation object with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0135] The light source device 11203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 11102 may be controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner, and the images may be synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

[0136] The light source device 11203 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, it is possible to irradiate an excitation light to a body tissue and observe the fluorescence from the body tissue (autofluorescence observation), or to locally inject a reagent such as indocyanine green (ICG) into the body tissue and irradiate the body tissue with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0137] FIG. 21 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0138] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other by a transmission cable 11400 so as to be able to communicate with each other.

[0139] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is configured by combining a plurality of lenses including a zoom lens and a focus lens.

[0140] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be one (so-called single-plate type) or multiple (so-called multi-plate type). When the imaging unit 11402 is composed of a multi-plate type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining the image signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (Dimensional) display. By performing 3D display, the surgeon 11131 can more accurately grasp the depth of the biological tissue in the surgical site. Note that when the imaging unit 11402 is composed of a multi-plate type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0141] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately behind the objective lens.

[0142] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be appropriately adjusted.

[0143] The communication unit 11404 is configured by a communication device for transmitting and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0144] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing the image, and / or information specifying the magnification and focus of the captured image.

[0145] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by a user, or may be automatically set by the control unit 11413 of the CCU 11201 based on an acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0146] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404.

[0147] The communication unit 11411 is configured with a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0148] Furthermore, the communication unit 11411 transmits, to the camera head 11102, a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0149] The image processing unit 11412 performs various types of image processing on the image signal, which is RAW data sent from the camera head 11102 .

[0150] The control unit 11413 performs various controls related to imaging of the surgical site etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0151] Further, the control unit 11413 causes the display device 11202 to display the captured image showing the surgical site, etc., based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition techniques. For example, the control unit 11413 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 11112 is used, etc., by detecting the shape and color of the edge of an object included in the captured image. When the control unit 11413 causes the display device 11202 to display the captured image, it may use the recognition result to superimpose various types of surgery support information on the image of the surgical site. By superimposing and presenting the surgery support information to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0152] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0153] Here, in the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0154] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the endoscope 11100, the camera head 11102 (the imaging unit 11402), the CCU 11201 (the image processing unit 11412), etc., among the above-described configurations.

[0155] Although an endoscopic surgery system has been described here as an example, the technology disclosed herein may also be applied to other systems, such as a microsurgery system.

[0156] <<16. Examples of applications to moving objects>> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.

[0157] FIG. 22 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.

[0158] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 22, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053 are illustrated.

[0159] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0160] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0161] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.

[0162] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0163] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.

[0164] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0165] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0166] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.

[0167] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 22, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.

[0168] FIG. 23 is a diagram showing an example of the installation position of the imaging unit 12031.

[0169] In FIG. 23, a vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as an imaging unit 12031.

[0170] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The images of the front acquired by the imaging units 12101 and 12105 are mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0171] 23 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

[0172] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.

[0173] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.

[0174] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0175] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

[0176] The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to, for example, the imaging unit 12031 and the like of the above-described configuration.

[0177] <<17. Supplementary Information>> Although the preferred embodiment of the present disclosure has been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0178] In addition, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above effects.

[0179] The present technology can also be configured as follows. (1) An imaging device comprising first and second imaging elements each converting light into an electric charge, Each of the first and second imaging elements A plurality of pixels disposed adjacent to each other in a semiconductor substrate; a pixel separation wall separating the adjacent pixels; a color filter provided above a light receiving surface of the semiconductor substrate, the color filter transmitting light having different wavelengths for the first imaging element and the second imaging element; having The pixel separation wall of the first imaging element includes: When viewed from the light receiving surface side, the first image sensor has a slit at the center thereof, The pixel separation wall of the second imaging element includes: When viewed from the light receiving surface side, there is no slit at the center of the second image sensor. Imaging device. (2) Each of the first and second imaging elements has two of the pixels. The imaging device according to (1) above. (3) Each of the first and second imaging elements has four of the pixels. The imaging device according to (1) above. (4) Each of the first and second imaging elements The imaging device further includes an element isolation wall that surrounds the plurality of pixels of each of the first and second imaging elements and isolates adjacent imaging elements from each other. The imaging device according to any one of (1) to (3) above. (5) the pixel isolation wall and the element isolation wall are provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, a depth of the pixel isolation wall with respect to the light receiving surface is shallower than a depth of the element isolation wall; The imaging device according to (4) above. (6) the pixel separation wall is provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, the element isolation wall is provided so as to penetrate the semiconductor substrate along a thickness direction of the semiconductor substrate; The imaging device according to (4) above. (7) The imaging device according to (5) or (6) above, wherein a depth of the pixel isolation wall of the first imaging element relative to the light receiving surface is greater than a depth of the pixel isolation wall of the second imaging element. (8) The imaging device according to any one of (4) to (7) above, wherein when viewed from the light receiving surface side, a width of the pixel isolation wall is smaller than a width of the element isolation wall. (9) Further comprising a third image sensor for converting light into an electric charge; The third imaging element is The plurality of pixels are provided in the semiconductor substrate and are adjacent to each other; the pixel separation wall separating the adjacent pixels; a color filter provided above the light receiving surface of the semiconductor substrate, the color filter transmitting light having a wavelength different from the wavelength of light transmitted by the color filters of the first and second image pickup elements; having The imaging device according to any one of (1) to (8) above. (10) The imaging device according to (9) above, wherein the pixel separation wall of the third imaging element has a slit at the center of the third imaging element when viewed from the light receiving surface side. (11) The imaging device according to (9) above, wherein the pixel separation wall of the third imaging element does not have a slit in the center of the third imaging element when viewed from the light receiving surface side. (12) The third imaging element is further comprising an element isolation wall surrounding the plurality of pixels of the third imaging element and isolating adjacent imaging elements from each other; In the third imaging element, the pixel isolation wall and the element isolation wall are provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, a depth of the pixel isolation wall with respect to the light receiving surface is shallower than a depth of the element isolation wall; The imaging device according to any one of (9) to (11) above. (13) The third imaging element is further comprising an element isolation wall surrounding the plurality of pixels of the third imaging element and isolating adjacent imaging elements from each other; In the third imaging element, the pixel separation wall is provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, the element isolation wall is provided so as to penetrate the semiconductor substrate along a thickness direction of the semiconductor substrate; The imaging device according to any one of (9) to (11) above. (14) The imaging device according to (12) or (13) above, wherein a depth of the pixel isolation wall of the third imaging element with respect to the light receiving surface is shallower than a depth of the pixel isolation wall of the second imaging element. (15) a light receiving section including a plurality of the image pickup elements arranged in a matrix on the light receiving surface of the semiconductor substrate; a depth of the pixel separation wall with respect to the light receiving surface in the image sensor in a central region of the light receiving section is shallower than a depth of the pixel separation wall in the image sensor in a peripheral region of the light receiving section; The imaging device according to any one of (1) to (14) above. (16) a light receiving section including a plurality of the image pickup elements arranged in a matrix on the light receiving surface of the semiconductor substrate; When viewed from the light receiving surface side, a width of the pixel separation wall in the image sensor in a central region of the light receiving unit is narrower than a width of the pixel separation wall in the image sensor in a peripheral region of the light receiving unit. The imaging device according to any one of (1) to (15) above. (17) An electronic device including an imaging device including first and second imaging elements that convert light into electric charges, Each of the first and second imaging elements A plurality of pixels disposed adjacent to each other in a semiconductor substrate; a pixel separation wall separating the adjacent pixels; a color filter provided above a light receiving surface of the semiconductor substrate, the color filter transmitting light having different wavelengths for the first imaging element and the second imaging element; having The pixel separation wall of the first imaging element includes: When viewed from the light receiving surface side, the first image sensor has a slit at the center thereof, The pixel separation wall of the second imaging element includes: When viewed from the light receiving surface side, there is no slit at the center of the second image sensor. electronic equipment. [Explanation of symbols]

[0180] 1. Imaging device 10. Semiconductor Substrate 10a Photosensitive surface 10b surface 30 Pixel array section 32 Vertical drive circuit section 34 Column signal processing circuit section 36 Horizontal drive circuit section 38 Output circuit section 40 Control circuit section 42 Pixel drive wiring 44 Vertical signal line 46 Horizontal signal line 48 Input / output terminal 100, 100a Image sensor 200 On-chip lens 202 Color Filter 204 Shading part 300, 300a, 300b, 300c, 300d pixels 302 Photoelectric conversion unit 304 pixel separation wall 310 Isolation Wall 400a, 400b Transfer gate

Claims

1. An imaging device comprising first and second imaging elements each converting light into an electric charge, Each of the first and second imaging elements A plurality of pixels disposed adjacent to each other in a semiconductor substrate; a pixel separation wall separating the adjacent pixels; a color filter provided above a light receiving surface of the semiconductor substrate, the color filter transmitting light having different wavelengths for the first imaging element and the second imaging element; having The pixel separation wall of the first imaging element includes: When viewed from the light receiving surface side, the first image sensor has a slit at the center thereof, The pixel separation wall of the second imaging element includes: When viewed from the light receiving surface side, the second image sensor does not have a slit at the center thereof. Imaging device.

2. Each of the first and second imaging elements has two of the pixels. The imaging device according to claim 1 .

3. Each of the first and second imaging elements has four of the pixels. The imaging device according to claim 1 .

4. Each of the first and second imaging elements The imaging device further includes an element isolation wall that surrounds the plurality of pixels of each of the first and second imaging elements and isolates adjacent imaging elements from each other. The imaging device according to claim 1 .

5. the pixel isolation wall and the element isolation wall are provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, a depth of the pixel isolation wall with respect to the light receiving surface is shallower than a depth of the element isolation wall; The imaging device according to claim 4.

6. the pixel separation wall is provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, the element isolation wall is provided so as to penetrate the semiconductor substrate along a thickness direction of the semiconductor substrate; The imaging device according to claim 4.

7. The imaging device according to claim 5 , wherein a depth of the pixel isolation wall of the first imaging element relative to the light receiving surface is greater than a depth of the pixel isolation wall of the second imaging element.

8. The imaging device according to claim 4 , wherein a width of the pixel isolation wall is narrower than a width of the element isolation wall when viewed from the light receiving surface side.

9. Further comprising a third image sensor for converting light into an electric charge; The third imaging element is The plurality of pixels are provided in the semiconductor substrate and are adjacent to each other; the pixel separation wall separating the adjacent pixels; a color filter provided above the light receiving surface of the semiconductor substrate, the color filter transmitting light having a wavelength different from the wavelength of light transmitted by the color filters of the first and second image pickup elements; having The imaging device according to claim 1 .

10. The imaging device according to claim 9 , wherein the pixel separation wall of the third imaging element has a slit at a center of the third imaging element when viewed from the light receiving surface side.

11. The imaging device according to claim 9 , wherein the pixel separation wall of the third imaging element does not have a slit at a center of the third imaging element when viewed from the light receiving surface side.

12. The third imaging element is a third imaging element is provided with a plurality of pixels, the third imaging element being surrounded by an element separation wall that separates adjacent imaging elements from each other; In the third imaging element, the pixel isolation wall and the element isolation wall are provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, a depth of the pixel isolation wall with respect to the light receiving surface is shallower than a depth of the element isolation wall; The imaging device according to claim 9.

13. The third imaging element is a third imaging element is provided with a plurality of pixels, the third imaging element being surrounded by an element separation wall that separates adjacent imaging elements from each other; In the third imaging element, the pixel separation wall is provided along a thickness direction of the semiconductor substrate so as to penetrate from the light receiving surface to a middle of the semiconductor substrate, the element isolation wall is provided so as to penetrate the semiconductor substrate along a thickness direction of the semiconductor substrate; The imaging device according to claim 9.

14. The imaging device according to claim 12 , wherein a depth of the pixel isolation wall of the third imaging element with respect to the light receiving surface is shallower than a depth of the pixel isolation wall of the second imaging element.

15. a light receiving section including a plurality of the image pickup elements arranged in a matrix on the light receiving surface of the semiconductor substrate; a depth of the pixel separation wall with respect to the light receiving surface in the image sensor in a central region of the light receiving section is shallower than a depth of the pixel separation wall in the image sensor in a peripheral region of the light receiving section; The imaging device according to claim 1 .

16. a light receiving section including a plurality of the image pickup elements arranged in a matrix on the light receiving surface of the semiconductor substrate; When viewed from the light receiving surface side, a width of the pixel separation wall in the image sensor in a central region of the light receiving unit is narrower than a width of the pixel separation wall in the image sensor in a peripheral region of the light receiving unit. The imaging device according to claim 1 .

17. An electronic device including an imaging device including first and second imaging elements that convert light into electric charges, Each of the first and second imaging elements A plurality of pixels disposed adjacent to each other in a semiconductor substrate; a pixel separation wall separating the adjacent pixels; a color filter provided above a light receiving surface of the semiconductor substrate, the color filter transmitting light having different wavelengths for the first imaging element and the second imaging element; having The pixel separation wall of the first imaging element includes: When viewed from the light receiving surface side, the first image sensor has a slit at the center thereof, The pixel separation wall of the second imaging element includes: When viewed from the light receiving surface side, the second image sensor does not have a slit at the center thereof. electronic equipment.

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