Light detection device and imaging device

Abstract

Provided is a light detection device capable of improving the accuracy of phase difference signals. The present invention comprises: a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array pattern in a row direction and column direction; a plurality of pixels each including two photoelectric conversion units aligned in the row direction; and microlenses that are disposed on the light incidence surface side of the semiconductor substrate and focus light that has passed through the imaging optical system of the imaging device onto each pixel. The present invention is also configured such that: the plurality of pixels include a plurality of special pixels; the special pixels have a light-shielding film covering either one end region or another end region in the row direction of the light incidence surface of specific photoelectric conversion units, which are at least some of two or more photoelectric conversion units; at least some of the plurality of special pixels are arranged apart from each other in the row direction; and the row-direction width of the light-shielding film of each special pixel varies according to the row-direction image height of the specific photoelectric conversion unit covered by the light-shielding film.

Description

Light detection device and imaging device

[0001] The present technology (technology according to the present disclosure) relates to a light detection device and an imaging device.

[0002] Conventionally, a photodetector has been proposed that includes a plurality of pupil-divided pixels, each of which includes a block including four photoelectric conversion units arranged in a 2×2 array and a microlens that focuses light for each block (see, for example, Patent Document 1). The photodetector disclosed in Patent Document 1 reads out pixel signals from the four photoelectric conversion units and obtains a phase difference signal from the read-out pixel signals.

[0003] JP 2016-15430 A

[0004] In such a photodetector, there is a demand for further improvement in the accuracy of the phase difference signal.

[0005] An object of the present disclosure is to provide a photodetector and an imaging device that can improve the accuracy of a phase difference signal.

[0006] The photodetector disclosed herein comprises (a) a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction; (b) a plurality of pixels including two or more photoelectric conversion units lined up in the first direction; and (c) a microlens arranged on the light incident surface side of the semiconductor substrate, which focuses light that has passed through the imaging optical system of the imaging device for each pixel; (d) the plurality of pixels include a plurality of special pixels; (e) the special pixels have a light-shielding film that covers one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units; and (f) at least some of the special pixels are arranged apart from each other in the first direction, and the width in the first direction of the light-shielding film of each special pixel differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers.

[0007] The imaging device disclosed herein comprises (a) a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction, (b) a plurality of pixels including two or more photoelectric conversion units lined up in the first direction, (c) and a microlens arranged on the light incident surface side of the semiconductor substrate and configured to focus light that has passed through the imaging optical system of the imaging device for each pixel, (d) the plurality of pixels including a plurality of special pixels, (e) the special pixels having a light-shielding film that covers one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units, and (f) a light detection device in which at least some of the plurality of special pixels are arranged apart from each other in the first direction and the width in the first direction of the light-shielding film of each special pixel differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers.

[0008] 13 is a diagram showing a schematic configuration of an imaging device according to a first embodiment; FIG. 14 is a diagram showing a planar configuration of a light receiving element; FIG. 15 is a diagram showing an enlarged view of the upper left corner of the light receiving element shown in FIG. 2; FIG. 16 is a diagram showing a cross-sectional configuration of the light receiving element when cut along line A-A in FIG. 3; FIG. 17 is a diagram showing a cross-sectional configuration of the light receiving element when cut along line B-B in FIG. 3; FIG. 18 is a diagram showing a cross-sectional configuration of the light receiving element when cut along line C-C in FIG. 3; FIG. 19 is a diagram showing a cross-sectional configuration of the light receiving element when cut along line D-D in FIG. 4; FIG. 20 is a diagram showing the potential of each part of a normal pixel and a special pixel; FIG. 21 is a diagram showing a planar configuration of a light receiving element according to a modified example; FIG. 22 is a diagram showing a planar configuration of a light receiving element according to a second embodiment; FIG. 23 is a diagram showing an extracted portion of the first group in FIG. 10; FIG. 24 is a diagram showing a planar configuration of a light receiving element according to a modified example; FIG. 25 is a diagram showing a cross-sectional configuration of a light receiving element when cut along line E-E in FIG. 13; FIG. 26 is a diagram showing the potential of each part of a normal pixel and a special pixel; FIG. 27 is a diagram showing a planar configuration of a light receiving element according to a modified example; FIG. 28 is a diagram showing a planar configuration of a light receiving element according to a modified example. 24. A diagram showing a configuration using a blue pixel as a special pixel. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing an enlarged view of the upper left corner of the light receiving element shown in FIG. 19. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing an image of subtraction between pixel signals performed in a signal processing unit. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing an extracted normal pixel at the center of the image height and a high image height from FIG. 24. A diagram showing an extracted special pixel at the center of the image height and a high image height from FIG. 24. A diagram showing an extracted special pixel at the center of the image height and a high image height from FIG. 24. A diagram showing the relationship between the angle of incidence of light and the normalized output of a photoelectric conversion unit. A diagram showing a pinhole pixel. A diagram showing a pixel signal of a pinhole pixel. A diagram showing an island pixel. A diagram showing a pixel signal of an island pixel. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing the potential of each part of a normal pixel and a special pixel. A diagram showing a planar configuration of a light receiving element according to a modified example. A diagram showing an enlarged view of the upper left corner of the light receiving element shown in FIG. 10A and 10B are diagrams illustrating potentials of various parts of a normal pixel and a special pixel.

[0009] An example of a photodetector and an imaging device according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 37. The embodiments of the present disclosure will be described in the following order. Note that the present disclosure is not limited to the following examples. Furthermore, the effects described in this specification are examples and are not limiting, and other effects may also be present. 1. First Embodiment 1-1 Configuration of imaging device 1-2 Configuration of light receiving element 1-3 Operation of signal processing unit 1-4 Configuration of pixel separation structure 1-5 Modification 2. Second Embodiment 2-1 Configuration of main parts 2-2 Modification

[0010] The present inventors have discovered the following problem with the photodetector described in Patent Document 1. When the photodetector described in Patent Document 1 is applied to, for example, an interchangeable lens imaging device, if a camera lens with a pupil distance that is significantly different from the expected pupil distance (the distance between the imaging surface of the light receiving element and the exit pupil of the camera lens) is attached, appropriate pixel signals cannot be obtained from the pupil-divided pixels, and the accuracy of the phase difference signal generated from the pixel signals may decrease.

[0011] 1. First Embodiment 1-1 Configuration of Imaging Device The configuration of an imaging device according to a first embodiment of the present disclosure will be described. FIG. 1 is a diagram illustrating a schematic configuration of an imaging device 100 according to the first embodiment. As illustrated in FIG. 1, the imaging device 100 includes a camera lens 101 (broadly speaking, an "imaging optical system"), a solid-state imaging device 102 (broadly speaking, a "photodetector"), a control unit 103, a storage unit 104, and a monitor 105. The imaging device 100 may be, for example, a lens-interchangeable digital still camera or digital video camera. The camera lens 101 guides incident light (image light) from a subject to a light-receiving element 106, forming an image on the imaging surface of the light-receiving element 106 (e.g., the effective pixel area of ​​the pixel area 2 shown in FIG. 2). The solid-state imaging device 102 includes the light-receiving element 106 and a signal processing unit 107. The light receiving element 106 converts the amount of incident light (image light) focused on the pixel region 2 (see FIG. 2 ) by the camera lens 101 into an electrical signal for each pixel. For example, a back-illuminated CMOS image sensor can be used. The converted electrical signal is output as a pixel signal to the signal processing unit 107. The signal processing unit 107 generates image data representing a captured image based on the pixel signal output from the light receiving element 106. The signal processing unit 107 also generates a phase difference signal based on the pixel signal. The generated image data and phase difference signal are output to the control unit 103. The control unit 103 controls the storage unit 104 and the monitor 105 to store the image data output from the signal processing unit 107 and display the captured image. The control unit 103 also controls the camera lens 101 to perform focus adjustment based on the phase difference signal output from the signal processing unit 107. The storage unit 104 stores image data generated by the solid-state imaging device 102, various parameters used by the control unit 103, and the like. For example, a flash memory can be used. The monitor 105 displays the captured image represented by the image data on its display surface. For example, a panel-type display device such as a liquid crystal panel, an organic EL (Electro Luminescence) panel, etc. The configuration of the light receiving element 106 and the operation of the signal processing unit 107 will be described below.

[0012] [1-2 Configuration of Light-Receiving Element] Next, the configuration of the light-receiving element 106 will be described. FIG. 2 is a diagram showing the planar configuration of the light-receiving element 106. FIG. 3 is an enlarged view of the upper left corner of the light-receiving element 106 shown in FIG. 2. FIG. 4 is a diagram showing the cross-sectional configuration of the light-receiving element 106 taken along line A-A in FIG. 3. FIG. 5 is a diagram showing the cross-sectional configuration of the light-receiving element 106 taken along line B-B in FIG. 3. FIG. 6 is a diagram showing the cross-sectional configuration of the light-receiving element 106 taken along line CC in FIG. 3. As shown in FIGS. 2 to 6, the light-receiving element 106 has a semiconductor substrate 1 (see FIG. 4), and a pixel region 2 (see FIG. 2) is formed in the semiconductor substrate 1. The pixel region 2 has a plurality of pixels 3 arranged in an array in the row direction (broadly speaking, the "first direction") and the column direction (broadly speaking, the "second direction"). Furthermore, the pixel 3 has two photoelectric conversion units PD1 and PD2. As shown in FIG. 7 , when viewed from the thickness direction of the semiconductor substrate 1, the photoelectric conversion units PD1 and PD2 are arranged adjacent to each other in the row direction (the left-right direction in FIG. 7 ), and each is formed into a rectangular shape extending in the column direction (the up-down direction in FIG. 7 ). That is, a plurality of pixels 3, each including two photoelectric conversion units PD1 and PD2 arranged in the row direction (broadly speaking, "two or more photoelectric conversion units arranged in a first direction"), are formed on the semiconductor substrate 1 to form a pixel region 2, and the plurality of photoelectric conversion units PD1 and PD2 are arranged in an array in the row and column directions. FIG. 7 is a diagram showing the cross-sectional configuration of the light receiving element 106 when broken along line D-D in FIG. 4. FIG. 7 illustrates a case where the photoelectric conversion unit on the right side is PD1 and the photoelectric conversion unit on the left side is PD2. The photoelectric conversion units PD1 and PD2 each have a p-type semiconductor region and an n-type semiconductor region, and the pn junction of these semiconductor regions forms a photodiode that generates charge (e.g., electrons) according to the amount of light received. The photoelectric conversion units PD1 and PD2 also accumulate charge generated by photoelectric conversion in capacitance generated at the pn junction. The accumulated charge is converted into pixel signals and output sequentially to the signal processing unit 107.

[0013] As shown in FIG. 2 , the pixel region 2 includes, as pixels 3, a plurality of normal pixels 4 and a plurality of special pixels 5. The normal pixels 4 are pixels for acquiring pixel signals for generating image data during normal shooting. Examples include red pixels R, blue pixels B, and green pixels Gr and Gb. Examples of pixel signals for generating image data include the sum of pixel signals based on charges generated by the photoelectric conversion units PD1 and PD2. The normal pixels 4 are also pixels for acquiring pixel signals for generating phase difference signals when a camera lens 101 having a basic pupil distance EPD0 (broadly speaking, a "predetermined pupil distance") is attached to the imaging device 100 during focus adjustment of the camera lens 101. The special pixels 5 are pixels for acquiring pixel signals for generating phase difference signals when a camera lens 101 having a first pupil distance EPD1, a second pupil distance EPD2, or a third pupil distance EPD3 (broadly speaking, a "predetermined pupil distance") is attached during focus adjustment of the camera lens 101. The magnitude relationship among EPD0, EPD1, EPD2, and EPD3 is EPD2<EPD0<EPD3<EPD1. As shown in FIG. 4, the pupil distance EPD can be the distance between the imaging surface of the light receiving element 106 and the exit pupil 55 of the camera lens 101. In the pixel region 2, as shown in FIG. 3, four pixels 3 arranged in a 2×2 array constitute a plurality of first blocks 6 and a plurality of second blocks 7. The first block 6 is a block formed by four normal pixels 4 arranged in a Bayer array. The second block 7 is a block formed by replacing the normal pixel 4 constituting the green pixel Gb in the first block 6 with a special pixel 5. FIG. 2 illustrates an example in which the special pixel 5 is configured to have a color filter 54 (see FIGS. 5 and 6) that transmits green light. For ease of viewing, the dot pattern representing the color filter 54 of the special pixel 5 is omitted from FIGS. 1 and 2.

[0014] As shown in FIG. 2 , the second blocks 7 are arranged in a column direction (vertical direction in FIG. 2 ) to form a block pair 8, with two second blocks 7 arranged in the column direction. The block pairs 8 are also arranged in a row direction (horizontal direction in FIG. 2 ) to form groups (hereinafter referred to as “first group 9,” “second group 10,” and “third group 11”) with a plurality of block pairs 8 arranged in the row direction (horizontal direction in FIG. 2 ). The special pixels 5 in the first group 9 are pixels for acquiring pixel signals for generating a phase difference signal when a camera lens 101 (short pupil lens) with a first pupil distance EPD1 is attached. The special pixels 5 in the second group 10 are pixels for acquiring pixel signals for generating a phase difference signal when a camera lens 101 (long pupil lens) with a second pupil distance EPD2 is attached. The special pixels 5 in the third group 11 are pixels for acquiring pixel signals for generating a phase difference signal when a camera lens 101 (medium pupil lens) with a third pupil distance EPD3 is attached. 2 illustrates an example in which the first group 9 is located at one end in the column direction (the upper end in the vertical direction in FIG. 2 ), the second group 10 is located at the other end in the column direction (the lower end in the vertical direction in FIG. 2 ), and the third group 11 is located between the first group 9 and the second group 10 (the middle in the vertical direction in FIG. 2 ). With the pixels 3 (normal pixels 4, special pixels 5) arranged in this manner, each of the first group 9, the second group 10, and the third group 11 includes a first pixel group 12 consisting of a plurality of special pixels 5 spaced apart from each other in the row direction (the horizontal direction in FIG. 2 ), and a second pixel group 13 consisting of a plurality of special pixels 5 spaced apart from each other in the row direction (the horizontal direction in FIG. 2 ) at a position spaced apart from the first pixel group 12 in the column direction (the vertical direction in FIG. 2 ). The special pixels 5 of the first pixel group 12 and the special pixels 5 of the second pixel group 13 are arranged at the same row position (the horizontal position in FIG. 2 ).

[0015] 4, 5, and 6, a plurality of microlenses 14 are arranged on the light incident surface (hereinafter also referred to as the "rear surface S1") of the semiconductor substrate 1. Each microlens 14 is arranged for each pixel 3, and condenses light L that has passed through the camera lens 101 of the imaging device 100 (see FIG. 1) for each pixel 3. The condensed light passes through color filters 54 (red, blue, and green filters) formed for each pixel 3 and is incident on each of the photoelectric conversion units PD1 and PD2. Each microlens 14 is arranged at a position where pupil correction has been performed. That is, when viewed from the thickness direction of the semiconductor substrate 1, the center of the microlens 14 is shifted toward the center of the pixel region 2 from the center of the pixel 3 as it moves from the center toward the periphery of the pixel region 2. 4 illustrates a case where, when viewed from the thickness direction of the semiconductor substrate 1, the microlens 14 is disposed at a pupil-corrected position such that a light-collection region X of light that passes through the camera lens 101 having a basic pupil distance EPD0 and is collected by the microlens 14 overlaps with the center of the pixel 3. By disposing the microlens 14 at a pupil-corrected position, when the camera lens 101 having the basic pupil distance EPD0 is attached to the imaging device 100, the position of the light-collection region X can be adjusted to the center of the pixel 3 (between the photoelectric conversion units PD1 and PD2) on the outer periphery side (high image height side) of the pixel region 2.

[0016] 5 and 6 , the special pixel 5 has a light-shielding film 15 on the back surface S1 side of the semiconductor substrate 1 (on the back surface S3 of the insulating film 29 in FIGS. 5 and 6 ). The light-shielding film 15 covers one end region or the other end region in the row direction (the right or left region in FIG. 3 ; in a broader sense, “the one end region or the other end region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of two or more photoelectric conversion units”) of the light incident surface (hereinafter also referred to as the “back surface S2”) of one of the two photoelectric conversion units PD1 or PD2 (hereinafter also referred to as the “specific photoelectric conversion unit 16”) of the special pixel 5. When a camera lens 101 having a pupil distance EPD1, EPD2, or EPD3 is attached, the specific photoelectric conversion unit 16 is a photoelectric conversion unit where a light collection region X of light L is located in the special pixel 5 for acquiring a phase difference signal corresponding to the pupil distance. Here, when the pupil distance EPD of the camera lens 101 is a short pupil shorter than the basic pupil distance EPD0, the angle of incidence of light L onto the light receiving element 106 increases, the light collection region X shifts toward the outer periphery of the pixel region 2 (toward the high image height), and the light collection region X moves into the photoelectric conversion unit PD1 or PD2 toward the outer periphery of the pixel region 2. On the other hand, when the pupil distance EPD of the camera lens 101 is a long pupil longer than the basic pupil distance EPD0, the angle of incidence of light L onto the light receiving element 106 decreases, the light collection region X shifts toward the center of the pixel region 2 (toward the center of the image height), and the light collection region X moves into the photoelectric conversion unit PD1 or PD2 toward the center of the pixel region 2. Therefore, when a camera lens 101 having a pupil distance other than the basic pupil distance EPD0 (first pupil distance EPD1, first pupil distance EPD1, first pupil distance EPD1) is attached to the imaging device 100, the light collection area X will be located away from the center of the pixel 3 and within the photoelectric conversion unit PD1 or PD2.

[0017] Furthermore, the specific photoelectric conversion units 16 are arranged in the same row direction position (left-right direction position in FIG. 3 ) among the specific photoelectric conversion units 16 of the special pixels 5 of the first pixel group 12 and the specific photoelectric conversion unit 16 of the special pixels 5 of the second pixel group 13, and these two specific photoelectric conversion units 16 form a photoelectric conversion unit pair 17. The photoelectric conversion unit pair 17 includes a first specific photoelectric conversion unit 18 that is located on one side in the row direction (right or left side in FIG. 3 ) of one special pixel 5 (special pixel 5 of the first pixel group 12 in FIG. 3 ) and has one end region in the row direction of its light incident surface (right region or left region in FIG. 3 ) covered with a light-shielding film 15. The second specific photoelectric conversion unit 19 is also included, and is located on one side in the row direction (the right or left side in FIG. 3 ) of another special pixel 5 (the special pixel 5 of the second pixel group 13 in FIG. 3 ), and has the other end region in the row direction of the light incident surface (the left region or the right region in FIG. 3 ) covered with a light-shielding film 15. The row-direction width W1 (or W4) of the light-shielding film 15 covering the light incident surface of the first specific photoelectric conversion unit 18 included in the same photoelectric conversion unit pair 17 is equal to the row-direction width W3 (or W2) of the region of the light incident surface of the second specific photoelectric conversion unit 19 that is not covered with the light-shielding film 15. The row-direction widths W1 and W4 of the light-shielding film 15 differ depending on the row-direction image height (the left or right direction in FIG. 3 ) of the specific photoelectric conversion unit 16 covered by the light-shielding film 15. For example, when viewed from the thickness direction of semiconductor substrate 1, widths W1 and W4 of light-shielding film 15 in the row direction are sized so that a light-collection region X of light L that passes through camera lens 101 having a predetermined pupil distance (any of first pupil distance EPD1, second pupil distance EPD2, and third pupil distance EPD3) and is collected by microlenses 14 overlaps with the row-direction ends of light-shielding film 15. In other words, widths W1 and W4 of light-shielding film 15 are widths that block half of light-collection region X and allow the remaining half to pass. As a result, light that passes through one side of exit pupil 55 of camera lens 101 in the row direction is blocked, and light that passes through the other side is allowed to pass. Figure 2 illustrates an example in which the widths W1 and W4 of the light-shielding film 15 of the special pixels 5 in the first group 9 are adjusted to a width corresponding to the first pupil distance EPD1, the widths W1 and W4 of the light-shielding film 15 of the special pixels 5 in the second group 10 are adjusted to a width corresponding to the second pupil distance EPD2, and the widths W1 and W4 of the light-shielding film 15 of the special pixels 5 in the third group 11 are adjusted to a width corresponding to the third pupil distance EPD3.Examples of materials for the light-shielding film 15 include tungsten (W) and aluminum (Al).

[0018] With such an arrangement of the light-shielding films 15, as shown in FIG. 2, when viewed from the thickness direction of the semiconductor substrate 1, the light-shielding films 15 include first light-shielding films 20 (the light-shielding films 15 in the second and fourth rows from the top in FIG. 2) whose row-direction widths W1 and W4 are sized so that the light-collection area X of light L that passes through the camera lens 101 having a predetermined first pupil distance EPD1 and is collected by the microlenses 14 overlaps with the row-direction ends of the light-shielding films 15, and second light-shielding films 21 (the light-shielding films 15 in the first and third rows from the bottom in FIG. 2) whose row-direction widths W1 and W4 overlap with the row-direction ends of the light-shielding films 15 The multiple photoelectric conversion unit pairs 17 are configured to include a first specific photoelectric conversion unit pair 22 (a pair of specific photoelectric conversion units 16 in the second and fourth rows from the top in Figure 2) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the first light-shielding film 20, and a second specific photoelectric conversion unit pair 23 (a pair of specific photoelectric conversion units 16 in the first and third rows from the bottom in Figure 2) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the second light-shielding film 21.

[0019] [1-3 Operation of the Signal Processing Unit] Next, the operation of the signal processing unit 107 will be described. During normal shooting, the signal processing unit 107 generates image data representing a captured image based on pixel signals output from the light receiving element 106. When generating image data, the sum of pixel signals from the two photoelectric conversion units PD1 and PD2 of a normal pixel 4 is used as the pixel signal of that normal pixel 4. The pixel signal of the special pixel 5 is complemented using the pixel signal of the normal pixel 4. During focus adjustment of the camera lens 101, the signal processing unit 107 generates a phase difference signal based on the pixel signals from the photoelectric conversion units PD1 and PD2 of the normal pixel 4 or the special pixel 5. The normal pixel 4 and the special pixel 5 used to acquire the phase difference signal are changed depending on the pupil distance EPD of the camera lens 101 attached to the imaging device 100. For example, when a camera lens 101 having a basic pupil distance EPD0 is attached, the light collection region X is located at the center of each pixel 3 (between the photoelectric conversion units PD1 and PD2). Therefore, different incident light beams (light that has passed through one side of the exit pupil 55 of the camera lens 101 in the row direction and light that has passed through the other side) are incident on the two photoelectric conversion units PD1 and PD2 of the normal pixel 4. Therefore, when a camera lens 101 having a basic pupil distance EPD0 is attached, the signal processing unit 107 generates a phase difference signal based on the pixel signals of the two photoelectric conversion units PD1 and PD2 of the normal pixel 4.

[0020] Furthermore, for example, when a camera lens 101 having a first pupil distance EPD1 is attached, the light collection region X is located on the row-direction end of the light-shielding film 15 of the special pixel 5 in the first group 9, as shown in FIG. 2 . Therefore, different incident light beams (light that has passed through one side of the exit pupil 55 of the camera lens 101 in the row direction and light that has passed through the other side in the row direction) are incident on the two specific photoelectric conversion units 16 of the two special pixels 5 that make up the photoelectric conversion unit pair 17. Therefore, when a camera lens 101 having the first pupil distance EPD1 is attached, the signal processing unit 107 generates a phase difference signal based on the pixel signals of the two specific photoelectric conversion units 16 that make up the photoelectric conversion unit pair 17 in the first group 9. Similarly, when a camera lens 101 having a second pupil distance EPD2 is attached, the signal processing unit 107 generates a phase difference signal based on the pixel signals of the two specific photoelectric conversion units 16 that make up the photoelectric conversion unit pair 17 in the second group 10. In addition, when a camera lens 101 having a third pupil distance EPD3 is attached, the signal processing unit 107 generates a phase difference signal based on the pixel signals of two specific photoelectric conversion units 16 that constitute a photoelectric conversion unit pair 17 in the third group 11.

[0021] Here, for example, if the pixel region 2 is configured to include only normal pixels 4, when a camera lens 101 having a pupil distance significantly different from the basic pupil distance EPD0 is attached, the normal pixels 4 will not provide appropriate pixel signals, and the accuracy of the phase difference signal generated from the pixel signals will decrease. In contrast, the imaging device 100 according to the first embodiment includes special pixels 5 having light-shielding films 15, as shown in FIG. 2 , and the row-direction widths W1 and W4 of the light-shielding films 15 of each special pixel 5 vary depending on the row-direction image height of the specific photoelectric conversion unit 16 covered by the light-shielding film 15. As a result, for example, when a camera lens 101 having a pupil distance significantly different from the basic pupil distance EPD0 is attached, a phase difference signal can be generated based on the acquired pixel signal by acquiring the pixel signal from the specific photoelectric conversion unit 16 of the special pixel 5. Therefore, the accuracy of the phase difference signal can be improved for camera lenses 101 with multiple pupil distances EPD.

[0022] [1-4 Configuration of Pixel Isolation Structure] Next, the configuration of the pixel isolation structure 24 will be described. As shown in FIG. 4 , the pixel isolation structure 24 is formed between the photoelectric conversion units PD1 and PD2 on the semiconductor substrate 1. That is, the pixel isolation structure 24 is formed in a lattice pattern on the semiconductor substrate 1 so as to surround each of the photoelectric conversion units PD1 and PD2. As shown in FIG. 7 , the pixel isolation structure 24 has a portion surrounding the periphery of a block formed by the photoelectric conversion units PD1 and PD2 within the same pixel 3 (hereinafter also referred to as an "inter-pixel isolation portion 25"), and a portion located between the photoelectric conversion units PD1 and PD2 within the region surrounded by the inter-pixel isolation portion 25 (hereinafter also referred to as an "intra-pixel isolation portion 26"). The inter-pixel isolation portion 25 has a trench portion 27, and a fixed charge film 28 and an insulating film 29 disposed within the trench portion 27. The trench portion 27 penetrates the semiconductor substrate 1 from the back surface S1 to the front surface S4 of the semiconductor substrate 1, and its sidewall surfaces form the outline of the pixel isolation structure 24. The fixed charge film 28 continuously covers the sidewall surfaces of the trench portion 27 and the rear surface S1 of the semiconductor substrate 1. The fixed charge film 28 may be made of, for example, a negatively charged high refractive index material film or a high dielectric film. The insulating film 29 is disposed in the space between the sidewall surfaces covered with the fixed charge film 28. In addition to covering the space, the insulating film 29 also covers the light incident surface of the fixed charge film 28 located on the rear surface S1 of the semiconductor substrate 1.

[0023] As shown in FIG. 7 , the intra-pixel isolation portion 26 is formed in a strip shape extending along the column direction (vertical direction in FIG. 7 ) when viewed in the thickness direction of the semiconductor substrate 1. Each longitudinal end has the same internal structure as the inter-pixel isolation portion 25, and includes an impurity layer 30 in the center. Like the inter-pixel isolation portion 25, the impurity layer 30 is formed from the front surface S4 side to the back surface S1 side. The impurity layer 30 may be, for example, a semiconductor region formed by doping the semiconductor substrate 1 with p-type impurities. The p-type impurity may be, for example, boron (B). With this configuration, the impurity layer 30 functions as an overflow path (hereinafter also referred to as a “first overflow path 31”) that allows charge to pass from one side of the adjacent photoelectric conversion portions PD1 and PD2 to the other. Therefore, for example, in a normal pixel 4, when the charge of one of the photoelectric conversion units PD1 and PD2 becomes saturated during normal shooting, the charge can be transferred to the other photoelectric conversion unit via the first overflow path 31, thereby preventing the charge of the photoelectric conversion units PD1 and PD2 from becoming saturated.

[0024] As shown in FIG. 4 , a floating diffusion FD is formed in the impurity layer 30 on the surface S4 of the semiconductor substrate 1. The floating diffusion FD can be, for example, a semiconductor region formed by doping the semiconductor substrate 1 with n-type impurities. A p-well region (pwell) is also formed on the surface S4 of the semiconductor substrate 1. The p-well region (pwell) includes an element isolation region (STI) for isolating pixel transistors and pixel transistors (e.g., a transfer transistor 32). The transfer transistor 32 is, for example, an n-channel conductivity MOSFET. The transfer transistor 32 is configured to form a channel between the photoelectric conversion units PD1 and PD2 and the floating diffusion FD, and includes a gate insulating film 33 and a gate electrode 34 sequentially stacked on the surface S4 of the semiconductor substrate 1. The transfer transistor 32 can transfer signal charges from the photoelectric conversion units PD1 and PD2, which function as source regions, to the floating diffusion FD, which functions as a drain region, by switching on and off in response to a gate-source voltage. The region in which the channel is formed by the transfer transistor 32 also functions as an overflow path (hereinafter also referred to as a "second overflow path 35") that allows charge to pass from the photoelectric conversion units PD1 and PD2 to the floating diffusion FD. Therefore, for example, in the normal pixel 4, when the charge in the photoelectric conversion units PD1 and PD2 becomes saturated, the charge can be moved to the floating diffusion FD via the second overflow path 35, and saturation of the charge in the photoelectric conversion units PD1 and PD2 can be avoided.

[0025] As shown in FIG. 8, in the normal pixel 4, the deepest potential PD Vmax and the deepest part OF of the potential of the first overflow path 31 Vmax and the deepest potential TG of the second overflow path 35 Vmax The relationship between the size and PD Vmax >OFF Vmax >TG VmaxAs a result, when the charge in one of the photoelectric conversion units PD1 and PD2 of the normal pixel 4 becomes saturated, the charge moves to the other photoelectric conversion unit, and when the charge in the other photoelectric conversion unit also becomes saturated, the charge moves to the floating diffusion FD. Vmax , OF Vmax and T.G. Vmax The magnitude relationship can be realized by adjusting the photoelectric conversion units PD1 and PD2, the p-well region pwell, the impurity concentration of the impurity layer 30, and the like.

[0026] In addition, in special pixel 5, PD Vmax , OF Vmax and T.G. Vmax The relationship between the magnitudes of PD Vmax >TG Vmax >OFF Vmax In other words, the potential of the second overflow path 35, which transfers charge overflowing from the photoelectric conversion units PD1 and PD2 of the special pixel 5 to the floating diffusion FD, is deeper than the potential of the first overflow path 31, which transfers charge between the two photoelectric conversion units PD1 and PD2 included in the special pixel 5. As a result, in the special pixel 5, when the charge of one of the photoelectric conversion units PD1 and PD2 becomes saturated, the charge does not move to the other photoelectric conversion unit, but moves only to the floating diffusion FD. Therefore, it is possible to suppress the transfer of charge between the specific photoelectric conversion unit 16 and the photoelectric conversion unit adjacent to that specific photoelectric conversion unit 16, and to suppress a decrease in the accuracy of the phase difference signal.

[0027] [1-5 Modifications] (1) In the first embodiment, as shown in FIG. 2 , an example was shown in which the first specific photoelectric conversion unit pair 22 is formed of the photoelectric conversion unit pairs 17 of the first group 9, and the second specific photoelectric conversion unit pair 23 is formed of the photoelectric conversion unit pairs 17 of the second group 10. However, other configurations may also be employed. For example, as shown in FIG. 9 , the first specific photoelectric conversion unit pair 22 and the second specific photoelectric conversion unit pair 23 may be formed of the photoelectric conversion unit pairs 17 of one group. FIG. 9 illustrates an example in which the photoelectric conversion units PD1 and PD2 located on one side in the row direction (left side or right side in FIG. 9 ) of two predetermined special pixels 5 (the special pixels 5 in the second and fourth rows from the top in FIG. 9 ) are the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 of the first specific photoelectric conversion unit pair 22, respectively. 9 illustrates a case where the photoelectric conversion units PD1 and PD2 located on the other side of the two special pixels 5 in the row direction (the right or left side in FIG. 9 ) are the first and second specified photoelectric conversion units 18 and 19 of the second specified photoelectric conversion unit pair 23. More specifically, in FIG. 9 , the second specified photoelectric conversion unit pair 23 corresponding to the camera lens 101 (long pupil lens) having the second pupil distance EPD2 is located toward the center of the pixel region 2, and the first specified photoelectric conversion unit pair 22 corresponding to the camera lens 101 (short pupil lens) having the first pupil distance EPD1 is located toward the outer periphery of the pixel region 2. With this configuration, the two photoelectric conversion units PD1 and PD2 of the special pixels 5 can be used as the specified photoelectric conversion units 16, allowing the photoelectric conversion units PD1 and PD2 of the special pixels 5 to be used more efficiently. Therefore, the number of available pupil distances EPD can be increased without increasing the number of special pixels 5.

[0028] 2. Second Embodiment [2-1 Configuration of Main Parts] Next, an imaging device 100 according to a second embodiment of the present disclosure will be described. The overall configuration of the imaging device 100 according to the second embodiment is the same as that shown in FIG. 1 and is therefore not shown. FIG. 10 is a diagram corresponding to FIG. 2 of the first embodiment. FIG. 11 is a diagram illustrating the first group 9 extracted from FIG. 10. FIG. 13 is a diagram corresponding to FIG. 7 of the first embodiment. In FIGS. 11 and 13, parts corresponding to those in FIGS. 2 and 7 are designated by the same reference numerals, and redundant description will be omitted. The second embodiment differs from the first embodiment in that, as shown in FIGS. 10 and 11, the pixel 3 includes four photoelectric conversion units PD1, PD2, PD3, and PD4 arranged in a 2×2 array. FIG. 11 illustrates a case where the upper right photoelectric conversion unit is PD1, the upper left photoelectric conversion unit is PD2, the lower right photoelectric conversion unit is PD3, and the lower left photoelectric conversion unit is PD4. In the second embodiment, one pair of two pairs of photoelectric conversion units (a pair of PD1 and PD3, and a pair of PD2 and PD4 in FIG. 11 ) arranged in the column direction included in the special pixel 5 is used as the specific photoelectric conversion unit 16. As a result, by using the sum of the pixel signals of the pair of photoelectric conversion units instead of the pixel signal of the specific photoelectric conversion unit 16 of the first embodiment, a phase difference signal can be generated as in the first embodiment. For example, in the special pixel 5 in the second row from the top and the third row from the left in FIG. 11 , the photoelectric conversion units PD2 and PD4 serve as the specific photoelectric conversion unit 16.

[0029] Furthermore, the specific photoelectric conversion units 16 are arranged in the same row direction position (left-right direction position in FIG. 11 ) among the specific photoelectric conversion units 16 of the special pixels 5 of the first pixel group 12 and the specific photoelectric conversion unit 16 of the special pixels 5 of the second pixel group 13, and these two specific photoelectric conversion units 16 form a photoelectric conversion unit pair 17. The photoelectric conversion unit pair 17 includes two first specific photoelectric conversion units 18 that are located on one side in the row direction (right or left side in FIG. 11 ) of one special pixel 5 (special pixel 5 of the first pixel group 12 in FIG. 11 ) and whose one end region in the row direction of the light incident surface (right region or left region in FIG. 11 ) is covered with a light-shielding film 15. The second specific photoelectric conversion unit pair 17 also includes two second specific photoelectric conversion units 19 that are located on one side in the row direction (the right or left side in FIG. 11 ) of another special pixel 5 (the special pixel 5 of the second pixel group 13 in FIG. 11 ) and have the other end side region in the row direction of the light incident surface (the left region or the right region in FIG. 11 ) covered with a light-shielding film 15. The row direction width W1 (or W4) of the light-shielding film 15 that covers the light incident surface of the first specific photoelectric conversion unit 18 included in the same photoelectric conversion unit pair 17 is equal to the row direction width W3 (or W2) of the region of the light incident surface of the second specific photoelectric conversion unit 19 that is not covered with the light-shielding film 15. Furthermore, when viewed from the thickness direction of semiconductor substrate 1, widths W1 and W4 of light-shielding film 15 in the row direction are sized so that a light-collection region X of light L that passes through camera lens 101 having a predetermined pupil distance (any of first pupil distance EPD1, second pupil distance EPD2, and third pupil distance EPD3) and is collected by microlenses 14 overlaps with the row-direction ends of light-shielding film 15. In other words, widths W1 and W4 of light-shielding film 15 are widths that block half of light-collection region X and allow the remaining half to pass. As a result, light that passes through one side in the row direction of exit pupil 55 of camera lens 101 is blocked, and light that passes through the other side can pass. Figures 10 and 11 illustrate an example in which the widths W1 and W4 of the light-shielding films 15 of the special pixels 5 in the first group 9 (see Figures 10 and 11) are adjusted to a width corresponding to the first pupil distance EPD1, the widths W1 and W4 of the light-shielding films 15 of the special pixels 5 in the second group 10 (see Figure 10) are adjusted to a width corresponding to the second pupil distance EPD2, and the widths W1 and W4 of the light-shielding films 15 of the special pixels 5 in the third group 11 (see Figure 10) are adjusted to a width corresponding to the third pupil distance EPD3.

[0030] With this arrangement of the light-shielding films 15, as shown in FIG. 10 , when viewed from the thickness direction of the semiconductor substrate 1, the light-shielding films 15 include first light-shielding films 20 (the light-shielding films 15 in the second and fourth rows from the top in FIG. 10 ) whose row-direction widths W1 and W4 are sized so that the light-collection area X of light L that passes through a camera lens 101 having a predetermined first pupil distance EPD1 and is collected by the microlenses 14 overlaps with the row-direction ends of the light-shielding films 15, and second light-shielding films 21 (the light-shielding films 15 in the first and third rows from the bottom in FIG. 2 ) whose row-direction widths W1 and W4 overlap with the row-direction ends of the light-shielding films 15 The plurality of photoelectric conversion unit pairs 17 are configured to include a first specific photoelectric conversion unit pair 22 (a pair of specific photoelectric conversion units 16 in the second and fourth rows from the top in FIG. 10 ) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the first light-shielding film 20, and a second specific photoelectric conversion unit pair 23 (a pair of specific photoelectric conversion units 16 in the first and third rows from the bottom in FIG. 10 ) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the second light-shielding film 21. Note that, at the special pixel 5 at the center (center of image height) of the pixel region 2, the angle of incidence of light L is 0°, and therefore, as shown in FIG. 12 , the light-shielding film 15 may be omitted.

[0031] In the second embodiment, as shown in FIG. 13 , the intra-pixel isolation portion 26 is located between the photoelectric conversion units PD1, PD2, PD3, and PD4 in the region surrounded by the inter-pixel isolation portion 25, and is formed in a cross shape extending in the row direction (the horizontal direction in FIG. 13 ) and the column direction (the vertical direction in FIG. 13 ) when viewed in the thickness direction of the semiconductor substrate 1. The intra-pixel isolation portion 26 is entirely formed of an impurity layer 30. As a result, the impurity layer 30 functions as an overflow path (hereinafter referred to as a “second overflow path 36”) that allows charge to pass from one side to the other between the two photoelectric conversion units PD1 and PD3, and between PD2 and PD4, which are arranged in the column direction (the vertical direction in FIG. 13 ). The impurity layer 30 also functions as an overflow path (hereinafter referred to as a “third overflow path 37”) that allows charge to pass from one side to the other between the two photoelectric conversion units PD1 and PD2, and between PD3 and PD4, which are arranged in the row direction (the horizontal direction in FIG. 13 ). Therefore, for example, in normal pixel 4, when the charge of one of the photoelectric conversion units PD1, PD2, PD3, and PD4 becomes saturated during normal imaging, the charge can be transferred to the other photoelectric conversion unit via the second overflow path 36 or the third overflow path 37, thereby preventing the charge of photoelectric conversion units PD1 to PD4 from becoming saturated.

[0032] 14 , a floating diffusion FD is formed in the impurity layer 30 on the surface S4 side of the semiconductor substrate 1. A p-well region pwell is also formed on the surface S4 side of the semiconductor substrate 1. An element isolation region STI for isolating pixel transistors and the like, and a pixel transistor (e.g., a transfer transistor 32) are formed in the p-well region pwell. The transfer transistor 32 is configured to form a channel between the photoelectric conversion units PD1, PD2, PD3, and PD4 and the floating diffusion FD, and includes a gate insulating film 33 and a gate electrode 34 sequentially stacked on the surface S4 of the semiconductor substrate 1. The transfer transistor 32 is turned on and off in response to a gate-source voltage, thereby transferring signal charges from the photoelectric conversion units PD1, PD2, PD3, and PD4, which function as source regions, to the floating diffusion FD, which functions as a drain region. The region in which the channel is formed by the transfer transistor 32 functions as an overflow path (hereinafter also referred to as a "first overflow path 38") that allows charge to pass from the photoelectric conversion units PD1 to PD4 to the floating diffusion FD. Therefore, for example, in the normal pixel 4, when the charge in the photoelectric conversion units PD1 to PD4 becomes saturated, the charge can be moved to the floating diffusion FD via the first overflow path 38, thereby preventing the charge from becoming saturated in the photoelectric conversion units PD1 to PD4. Figure 14 is a diagram showing the cross-sectional configuration of the light-receiving element 106 when broken along line E-E in Figure 13.

[0033] As shown in FIG. 15, in the normal pixel 4, the deepest potential PD Vmax and the deepest part OF2 of the potential of the second overflow path 36 Vmax and the deepest part OF3 of the potential of the third overflow path 37 Vmax and the deepest potential TG of the first overflow path 38 Vmax The relationship between the magnitude and PD Vmax >OF2 Vmax >OF3 Vmax >TG VmaxAs a result, when the charge of any of the photoelectric conversion units PD1 to PD4 of the normal pixel 4 becomes saturated, the charge moves to the photoelectric conversion unit in the same column as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same column also becomes saturated, the charge moves to the photoelectric conversion unit in the same row as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same row also becomes saturated, the charge moves to the floating diffusion FD. PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The magnitude relationship can be realized by adjusting the photoelectric conversion units PD1 to PD4, the p-well region pwell, the impurity concentration of the impurity layer 30, and the like.

[0034] In addition, in special pixel 5, PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The relationship between the magnitudes of PD Vmax >OF2 Vmax >TG Vmax >OF3 Vmax In other words, the potential of the second overflow path 36, which transfers charges between two photoelectric conversion units aligned in the column direction among the four photoelectric conversion units PD1 to PD4 included in the special pixel 5, is the deepest, the potential of the first overflow path 38, which transfers charges overflowing from the photoelectric conversion units PD to PD4 of the special pixel 5 to the floating diffusion FD, is the second deepest, and the potential of the third overflow path 37, which transfers charges between two photoelectric conversion units aligned in the row direction among the four photoelectric conversion units PD1 to PD4 included in the special pixel 5, is the third deepest. As a result, in the special pixel 5, when the charge of one of the photoelectric conversion units PD1 to PD4 becomes saturated, the charge moves to the photoelectric conversion unit in the same column as the saturated photoelectric conversion unit, and when the charge of the photoelectric conversion unit in the same column also becomes saturated, the charge moves to the floating diffusion FD. Therefore, it is possible to suppress the transfer of charges between a specific photoelectric conversion unit 16 and a photoelectric conversion unit in the same row as the specific photoelectric conversion unit 16, and to suppress a decrease in the accuracy of the phase difference signal.

[0035] [2-2 Modifications] (1) In the second embodiment, as shown in FIG. 10 , an example was shown in which the first specific photoelectric conversion unit pair 22 is formed of the photoelectric conversion unit pairs 17 of the first group 9, and the second specific photoelectric conversion unit pair 23 is formed of the photoelectric conversion unit pairs 17 of the second group 10. However, other configurations may also be employed. For example, as shown in FIG. 16 , the first specific photoelectric conversion unit pair 22 and the second specific photoelectric conversion unit pair 23 may be formed of the photoelectric conversion unit pairs 17 of one group. FIG. 16 illustrates an example in which a pair of photoelectric conversion units PD1 and PD3 or PD2 and PD4 located on one side in the row direction (the right side or the left side in FIG. 16 ) of two specific special pixels 5 (the special pixels 5 in the second and fourth rows from the top in FIG. 16 ) are the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 of the first specific photoelectric conversion unit pair 22, respectively. FIG. 16 also illustrates a case where the pair of photoelectric conversion units PD2 and PD4, or PD1 and PD3, located on the other side of the two special pixels 5 in the row direction (the left or right side in FIG. 16 ) are respectively configured as the first and second specified photoelectric conversion units 18 and 19 of the second specified photoelectric conversion unit pair 23. This configuration allows the four photoelectric conversion units PD1 to PD4 of the special pixel 5 to be used as the specified photoelectric conversion units 16, thereby enabling more efficient use of the photoelectric conversion units PD1 to PD4 of the special pixel 5. Therefore, the number of applicable pupil distances EPD can be increased without increasing the number of special pixels 5. Note that, since the angle of incidence of light L is 0° for the special pixel 5 at the center of the pixel area 2 (center of image height), the light-shielding film 15 may be omitted as shown in FIG. 17 . (2) In the second embodiment, an example was shown in which the green pixel Gb was replaced with the special pixel 5 as shown in FIG. 10 , but other configurations may also be adopted. 18, the pixels 3 (red pixel R, blue pixel B, green pixel Gr) other than the green pixel Gb may be replaced with the special pixel 5. FIG. 18 illustrates an example in which the blue pixel B is used as the special pixel 5.

[0036] (3) In the second embodiment, one pair of photoelectric conversion units (PD1 and PD3, and PD2 and PD4) in the special pixel 5 is used as the specific photoelectric conversion unit 16 in the first embodiment. However, other configurations may be employed. For example, as shown in FIGS. 19 and 20 , one of the four photoelectric conversion units PD1 to PD4 included in the special pixel 5 may be used as the specific photoelectric conversion unit 16 in the first embodiment. This allows a phase difference signal to be generated similarly to the first embodiment by using the pixel signal of one of the four photoelectric conversion units PD1 to PD4 instead of the pixel signal of the specific photoelectric conversion unit 16 in the first embodiment. For example, in the special pixel 5 in the second row from the top and the third row from the left in FIG. 19 , the photoelectric conversion units PD2 and PD4 each serve as the specific photoelectric conversion unit 16. FIG. 20 is an enlarged view of the upper left corner of the light receiving element 106 shown in FIG. 19 .

[0037] Furthermore, the specific photoelectric conversion units 16 are arranged in the same row direction position (left-right direction position in FIG. 19 ) among the specific photoelectric conversion units 16 of the special pixels 5 of the first pixel group 12 and the specific photoelectric conversion unit 16 of the special pixels 5 of the second pixel group 13, and these two specific photoelectric conversion units 16 form a photoelectric conversion unit pair 17. The photoelectric conversion unit pair 17 includes a first specific photoelectric conversion unit 18 that is located on one side in the row direction (right or left side in FIG. 19 ) of one special pixel 5 (the special pixel 5 of the first pixel group 12 in FIG. 19 ) and whose one end region in the row direction of the light incident surface (right region or left region in FIG. 19 ) is covered with a light-shielding film 15. Also included is a second specified photoelectric conversion unit 19 that is located on one side in the row direction (the right or left side in FIG. 19 ) of another special pixel 5 (the special pixel 5 of the second pixel group 13 in FIG. 19 ) and has the other end side region in the row direction of the light incident surface (the left side region or the right side region in FIG. 19 ) covered with a light-shielding film 15. The row direction width W1 (or W4) of the light-shielding film 15 that covers the light incident surface of the first specified photoelectric conversion unit 18 included in the same photoelectric conversion unit pair 17 is equal to the row direction width W3 (or W2) of the region of the light incident surface of the second specified photoelectric conversion unit 19 that is not covered with the light-shielding film 15. Furthermore, when viewed from the thickness direction of the semiconductor substrate 1, the row direction widths W1 and W4 of the light-shielding film 15 are sized so that the light-collection region X of light L that passes through the camera lens 101 having a predetermined pupil distance (either the first pupil distance EPD1, the second pupil distance EPD2, or the third pupil distance EPD3) and is collected by the microlens 14 overlaps with the row direction end of the light-shielding film 15. That is, the widths W1 and W4 of the light-shielding film 15 are sized to block half of the light-collection region X and allow the other half to pass. This blocks light that passes through one side of the exit pupil 55 of the camera lens 101 in the row direction, while allowing light that passes through the other side to pass. Figure 19 illustrates an example in which the widths W1 and W4 of the upper light-shielding film 15 of the special pixels 5 in the first group 9 are adjusted to a width corresponding to the first pupil distance EPD1, and the widths W1 and W4 of the lower light-shielding film 15 are adjusted to a width corresponding to the second pupil distance EPD2. Although not shown, the widths of the light-shielding films 15 of the second group 10 and the third group 11 (see FIG. 2) are also adjusted in the same manner.

[0038] With this arrangement of the light-shielding film 15, as shown in FIG. 19 , when viewed from the thickness direction of the semiconductor substrate 1, the light-shielding film 15 includes a first light-shielding film 20 (the light-shielding film 15 located above the special pixels 5 in the second and fourth rows from the top in FIG. 19 ) whose row-direction widths W1 and W4 are such that the light-collection area X of light L that passes through the camera lens 101 having a first pupil distance EPD1 and is collected by the microlens 14 overlaps with the row-direction end of the light-shielding film 15, and a second light-shielding film 21 (the light-shielding film 15 located below the special pixels 5 in the second and fourth rows from the top in FIG. 19 ) whose row-direction widths W1 and W4 are such that the light-collection area X of light L that passes through the camera lens 101 having a second pupil distance EPD2 different from the first pupil distance EPD1 and is collected by the microlens 14 overlaps with the row-direction end of the light-shielding film 15. The multiple photoelectric conversion unit pairs 17 are configured to include a first specific photoelectric conversion unit pair 22 (a pair of specific photoelectric conversion units 16 located on the upper side of the special pixels 5 in the second and fourth rows from the top in Figure 19) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the first light-shielding film 20, and a second specific photoelectric conversion unit pair 23 (a pair of specific photoelectric conversion units 16 located on the lower side of the special pixels 5 in the second and fourth rows from the top in Figure 19) in which the light-shielding film 15 covering the light incident surfaces of the first specific photoelectric conversion unit 18 and the second specific photoelectric conversion unit 19 is the second light-shielding film 21.

[0039] 19 , one photoelectric conversion unit (the upper photoelectric conversion unit PD1 or PD2 in FIG. 19 ) of a pair of photoelectric conversion units (a pair of PD1 and PD2, and a pair of PD3 and PD4) located on one side in the column direction (the upper side in FIG. 19 ) of two predetermined special pixels 5 (the special pixels 5 in the second and fourth rows from the top in FIG. 19 ) corresponds to the first specified photoelectric conversion unit 18 and the second specified photoelectric conversion unit 19 of the first specified photoelectric conversion unit pair 22. Also, in FIG. 19 , one photoelectric conversion unit (the lower photoelectric conversion unit PD3 or PD4 in FIG. 19 ) of a pair of photoelectric conversion units located on the other side in the column direction (the lower side in FIG. 19 ) of the two special pixels 5 corresponds to the first specified photoelectric conversion unit 18 and the second specified photoelectric conversion unit 19 of the second specified photoelectric conversion unit pair 23. With the above configuration, the light receiving element 106 of this modification has half the number of photoelectric conversion units used to generate phase difference signals compared to the light receiving element 106 of the second embodiment, so that sensitivity is reduced to half, but the number of applicable pupil distances EPD can be doubled. Note that, while Fig. 19 shows, as an example, a case where the shape of the light-shielding film 15 is rectangular when viewed from the thickness direction of the semiconductor substrate 1, it may also be trapezoidal, as shown in Fig. 21.

[0040] (4) In the second embodiment, a phase difference signal is generated based on pixel signals from two specific photoelectric conversion units 16 (the specific photoelectric conversion unit 16 in the first pixel group 12 and the specific photoelectric conversion unit 16 in the second pixel group 13) that constitute the photoelectric conversion unit pair 17. However, other configurations may be employed. For example, as shown in FIG. 22 , a configuration may be employed in which only one of the two specific photoelectric conversion units 16 that constitute the photoelectric conversion unit pair 17 is included. FIG. 22 illustrates a configuration in which the specific photoelectric conversion unit 16 is omitted from the second pixel group 13 in the configuration of the pixel region 2 shown in FIG. 11 , and the specific photoelectric conversion unit 16 is included only in the first pixel group 12. A photoelectric conversion unit without a light-shielding film 15 is disposed in the location where the specific photoelectric conversion unit 16 is omitted. That is, in FIG. 22 , the special pixel 5 in the second pixel group 13 is replaced with a normal pixel 4 in the configuration of the pixel region 2 shown in FIG. 11 .

[0041] In this case, when adjusting the focus of the camera lens 101, the signal processing unit 107 generates a pixel signal by subtracting the pixel signals (hereinafter also referred to as "second pixel signals") of two first specific photoelectric conversion units 18 (photoelectric conversion units PD2 and PD4 in FIG. 23) located on one side of the row direction of the special pixel 5 (right or left side in FIG. 22) and whose light incident surfaces are covered with a light-shielding film 15 from the pixel signals (hereinafter also referred to as "first pixel signals") of two photoelectric conversion units (photoelectric conversion units PD2 and PD4 in FIG. 23) located on one side of the row direction of the replaced normal pixel 4 (right or left side in FIG. 22 and FIG. 23) and whose light incident surfaces are not covered with a light-shielding film 15, as shown in FIG. 22 and FIG. 23. The two photoelectric conversion units of the normal pixel 4 used for subtraction can be, for example, the two photoelectric conversion units of the normal pixel 4 in FIG. 22 located at the location where the first specified photoelectric conversion unit 18 and the second specified photoelectric conversion unit 19 that constitutes the photoelectric conversion unit pair 17 in FIG. 11 are located. For example, in FIG. 22, if the photoelectric conversion units PD2 and PD4 of the special pixel 5 in the second row from the top and the third row from the left are selected as the specified photoelectric conversion unit 16 to be used for subtraction, the photoelectric conversion units PD2 and PD4 of the normal pixel 4 in the first row from the bottom and the third row from the left in FIG. 22 are used as the photoelectric conversion unit of the normal pixel 4 to be used for subtraction. As shown in FIG. 23, the pixel signal generated by the subtraction is a pixel signal obtained by the second specified photoelectric conversion unit 19 that constitutes the photoelectric conversion unit pair 17 in FIG. 11 with the first specified photoelectric conversion unit 18. As a result, by using the pixel signal generated by the subtraction described above instead of the pixel signal of the second specified photoelectric conversion unit 19 in the second embodiment, a phase difference signal can be generated in the same way as in the second embodiment. Fig. 23 is a diagram showing an image of subtraction between pixel signals performed by the signal processing unit 107.

[0042] (5) For example, as shown in FIG. 24 , the pixel region 2 shown in FIG. 16 may have the specific photoelectric conversion unit 16 omitted from the second pixel group 13. That is, in FIG. 24 , the pixel region 2 shown in FIG. 16 has the special pixel 5 of the second pixel group 13 replaced with a normal pixel 4. Note that FIG. 24 illustrates a case where the width pattern of the first light-shielding film 20 of the first pixel group 12 is replaced with the width pattern of the first light-shielding film 20 of the second pixel group 13. With this configuration, when a camera lens 101 having a basic pupil distance EPD0 is attached to the imaging device 100, the light-collection region X is located at the center of the normal pixel 4 (i.e., between the photoelectric conversion units PD1 to PD4), as shown in FIG. 25 . Therefore, a phase difference signal can be generated using the pixel signals of the four photoelectric conversion units PD1 to PD4 of the normal pixel 4. FIG. 25 is a diagram illustrating the normal pixel 4 at the center of the image height and at a high image height, as shown in FIG. 24 . Furthermore, when a camera lens 101 having a first pupil distance EPD1 is attached to the imaging device 100, the light collection region X is located on an end of the first light-shielding film 20 in the row direction, as shown in Fig. 26, and therefore a phase difference signal can be generated by using the pixel signals of the two specific photoelectric conversion units 16 having the first light-shielding film 20 and the pixel signal generated by the subtraction shown in Fig. 26. Similarly, when a camera lens 101 having a second pupil distance EPD2 is attached to the imaging device 100, the light collection region X is located on an end of the second light-shielding film 21 in the row direction, as shown in Fig. 27, and therefore a phase difference signal can be generated by using the pixel signals of the two specific photoelectric conversion units 16 having the second light-shielding film 21 and the pixel signal generated by the subtraction shown in Fig. 26. Figs. 26 and 27 are diagrams illustrating the special pixels 5 at the center of the image height and at high image heights, extracted from Fig. 24.

[0043] Here, when the pixel region 2 shown in FIG. 24 is used and the signal processing unit 107 performs the subtraction shown in FIG. 26 , the pixel signal obtained is as shown in the graph in FIG. 28 . In the graph in FIG. 28 , the horizontal axis represents the angle of incidence of light L, and the vertical axis represents a signal (normalized output) obtained by normalizing the pixel signal of the photoelectric conversion unit. The graph in FIG. 28 shows, as normalized outputs, pixel signals (hereinafter also referred to as “first pixel signals”) from the photoelectric conversion units PD1 to PD4 of a pinhole pixel 40 (see FIG. 29 ) having a structure equivalent to the special pixel 5 shown in FIG. 24 , pixel signals (hereinafter also referred to as “second pixel signals”) from the photoelectric conversion units PD1 to PD4 of a normal pixel 4, and a pixel signal (hereinafter also referred to as “third pixel signal”) obtained by subtracting the first pixel signal from the second pixel signal. As shown in FIG. 29 , the pinhole pixel 40 is a pixel having a pinhole light-shielding film 41 that opens the center of the pixel 3 and shields the outer periphery from light. The first pixel signals output from the photoelectric conversion units PD1 to PD4 of the pinhole pixel 40 are pixel signals obtained when light L passing through the outer periphery of the camera lens 101 is blocked, as shown in Fig. 30, and therefore have low separability. Also, the third pixel signal is equivalent to the pixel signals of the photoelectric conversion units PD1 to PD4 of the island pixel 43, which has an island light-shielding film 42 that shields the center of the pixel 3, as shown in Fig. 31. Therefore, the third pixel signal is a pixel signal obtained when light L passing through the center of the camera lens 101 is blocked, as shown in Fig. 32, and therefore has high separability.

[0044] 28 includes a pixel signal with high separability (first pixel signal), a pixel signal with low separability (third pixel signal), and a pixel signal with intermediate separability (second pixel signal), and therefore three intersections (first intersection 44, second intersection 45, and third intersection 46) of the first to third pixel signals appear near a normalized output of 0.5. The first intersection 44 and the third intersection 46 are intersections between the pixel signal of the pinhole pixel 40 and the pixel signal of the island pixel 43. The second intersection 45 is an intersection between the pixel signal of the photoelectric conversion unit on the left side of the normal pixel 4 and the pixel signal of the photoelectric conversion unit on the right side. Therefore, with a photodetector 106 having a pinhole pixel 40 (a photodetector 106 having a special pixel 5 shown in FIG. 24 ), when a camera lens 101 having an angle of incidence corresponding to the three intersections, that is, a camera lens 101 having a pupil distance EPD at which these angles of incidence can be obtained, is attached to the imaging device 100, it becomes possible to generate a highly accurate phase difference signal.

[0045] (6) Although the second embodiment illustrates an example in which the first pixel group 12 and the second pixel group 13 are formed by a plurality of special pixels 5 arranged in a row direction, other configurations may also be employed. For example, as shown in FIG. 33 , the first pixel group 12 and the second pixel group 13 may be formed by a plurality of special pixels 5 arranged in a column direction. FIG. 33 illustrates an example in which the second pixel group 13 is formed in the same column as the first pixel group 12, and the special pixels 5 of the first pixel group 12 and the special pixels 5 of the second pixel group 13 alternate. In this case, one pair of photoelectric conversion units out of two pairs of photoelectric conversion units arranged in a row direction (in FIG. 33 , the pair PD1 and PD2, and the pair PD3 and PD4) included in the special pixel 5 is used as the specific photoelectric conversion unit 16. As a result, a phase difference signal can be generated similarly to the second embodiment by using the sum of the pixel signals of the pair of photoelectric conversion units instead of the pixel signal of the specific photoelectric conversion unit 16 of the second embodiment. For example, in the special pixel 5 in the second row from the top and the third row from the left in FIG. 33, the photoelectric conversion units PD1 and PD2 are the specific photoelectric conversion units 16.

[0046] Furthermore, the specific photoelectric conversion units 16 are arranged in positions close to each other (positions sandwiching a normal pixel 4 in FIG. 33 ) among the specific photoelectric conversion units 16 of the special pixels 5 of the first pixel group 12 and the specific photoelectric conversion units 16 of the special pixels 5 of the second pixel group 13, and form a photoelectric conversion unit pair 17. The photoelectric conversion unit pair 17 includes two first specific photoelectric conversion units 18 that are located on one side in the column direction (upper or lower in FIG. 33 ) of one special pixel 5 (the special pixel 5 in the second row from the top and third row from the left, and the special pixel 5 in the first row from the bottom and third row from the left in FIG. 33 ) and whose one end region in the column direction of the light incident surface (the upper region or lower region in FIG. 33 ) is covered with a light-shielding film 15. Furthermore, the photoelectric conversion unit pair 17 includes two second specific photoelectric conversion units 19 that are located on one side in the column direction (upper or lower side in FIG. 33 ) of other special pixels 5 (the special pixel 5 in the fourth row from the top and the third row from the left, and the special pixel 5 in the third row from the bottom and the third row from the left in FIG. 33 ) and have the other end region in the column direction of the light incident surface (lower region or upper region in FIG. 33 ) covered with a light-shielding film 15. Furthermore, the column direction width W1 (or W4) of the light-shielding film 15 that covers the light incident surface of the first specific photoelectric conversion unit 18 included in the same photoelectric conversion unit pair 17 is equal to the column direction width W3 (or W2) of the region of the light incident surface of the second specific photoelectric conversion unit 19 that is not covered with the light-shielding film 15. Furthermore, when viewed from the thickness direction of the semiconductor substrate 1, the column-direction widths W1 and W4 of the light-shielding film 15 are sized so that the light-collection region X of light L that passes through the camera lens 101 having a predetermined pupil distance (either the first pupil distance EPD1, the second pupil distance EPD2, or the third pupil distance EPD3) and is collected by the microlenses 14 overlaps with the column-direction end of the light-shielding film 15. That is, the widths W1 and W4 of the light-shielding film 15 are set to block half of the light-collection region X and allow the remaining half to pass through. Figure 33 illustrates an example in which the widths W1 and W4 of the light-shielding film 15 of the special pixels 5 in the first group 9 are adjusted to a width corresponding to the first pupil distance EPD1. With this configuration, the light-receiving element 106 according to this modification can acquire a vertical phase difference signal as a phase difference signal.

[0047] 34, in the normal pixel 4 of the modified example shown in FIG. 33, the deepest potential PD Vmaxand the deepest part OF2 of the potential of the second overflow path 36 Vmax and the deepest part OF3 of the potential of the third overflow path 37 Vmax and the deepest potential TG of the first overflow path 38 Vmax The relationship between the magnitude and PD Vmax >OF2 Vmax >OF3 Vmax >TG Vmax As a result, when the charge of any of the photoelectric conversion units PD1 to PD4 of the normal pixel 4 becomes saturated, the charge moves to the photoelectric conversion unit in the same row as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same row also becomes saturated, the charge moves to the photoelectric conversion unit in the same column as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same column also becomes saturated, the charge moves to the floating diffusion FD. PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The magnitude relationship can be realized by adjusting the photoelectric conversion units PD1 to PD4, the p-well region pwell, the impurity concentration of the impurity layer 30, and the like.

[0048] In addition, in special pixel 5, PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The relationship between the magnitudes of PD Vmax >OF2 Vmax >TG Vmax >OF3 VmaxIn other words, the potential of the second overflow path 36, which transfers charges between two photoelectric conversion units aligned in the row direction among the four photoelectric conversion units PD1 to PD4 included in the special pixel 5, is the deepest, the potential of the first overflow path 38, which transfers charges overflowing from the photoelectric conversion units PD to PD4 of the special pixel 5 to the floating diffusion FD, is the second deepest, and the potential of the third overflow path 37, which transfers charges between two photoelectric conversion units aligned in the column direction among the four photoelectric conversion units PD1 to PD4 included in the special pixel 5, is the third deepest. As a result, in the special pixel 5, when the charge of one of the photoelectric conversion units PD1 to PD4 becomes saturated, the charge moves to the photoelectric conversion unit in the same row as the saturated photoelectric conversion unit, and when the charge of the photoelectric conversion unit in the same row also becomes saturated, the charge moves to the floating diffusion FD. Therefore, it is possible to suppress the transfer of charges between a specific photoelectric conversion unit 16 and a photoelectric conversion unit in the same column as the specific photoelectric conversion unit 16, and to suppress a decrease in the accuracy of the phase difference signal.

[0049] (7) Furthermore, for example, as shown in Figures 35 and 36, in addition to the structure of the special pixel 5 shown in Figure 11, the special pixel 5 may further include second light-shielding films 50, 51 (broadly speaking, "second-direction light-shielding films") covering one end region or the other end region in the column direction of the light incident surface of the specific photoelectric conversion unit 16 (the upper region or the lower region in Figure 35). The second light-shielding films 50, 51 have the same structure as the first and second light-shielding films 20, 21 shown in Figure 33. That is, when viewed from the thickness direction of the semiconductor substrate 1, the column-direction width W1 (or W4) of the second light-shielding films 50, 51 is large enough to overlap the column-direction end of the second light-shielding film 50 with the light-collection region X of light L that passes through the camera lens 101 having a predetermined pupil distance (any of the first pupil distance EPD1, the second pupil distance EPD2, and the third pupil distance EPD3) and is collected by the microlens 14. At the locations where the light-shielding film 15 and the second light-shielding film 50 overlap, the light-shielding film 15 and the second light-shielding film 50 are integrated. Also, in Fig. 35, the photoelectric conversion unit corresponding to the first specified photoelectric conversion unit 18 in Fig. 33 is indicated by reference numeral 52, and the photoelectric conversion unit corresponding to the second specified photoelectric conversion unit 19 is indicated by reference numeral 53. With this configuration, the light-receiving element 106 according to this modification can acquire both a horizontal phase difference signal and a vertical phase difference signal as phase difference signals, and can also accommodate a plurality of pupil distances EPD. Fig. 36 is an enlarged view of the upper left corner of the light-receiving element 106 shown in Fig. 35.

[0050] 37, in the normal pixel 4 of the modified example shown in FIG. 35, the deepest potential PD Vmax and the deepest part OF2 of the potential of the second overflow path 36 Vmax and the deepest part OF3 of the potential of the third overflow path 37 Vmax and the deepest potential TG of the first overflow path 38 Vmax The relationship between the size and PD Vmax >OF2 Vmax >OF3 Vmax >TG VmaxAs a result, when the charge of any of the photoelectric conversion units PD1 to PD4 of the normal pixel 4 becomes saturated, the charge moves to the photoelectric conversion unit in the same column as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same column also becomes saturated, the charge moves to the photoelectric conversion unit in the same row as the photoelectric conversion unit whose charge is saturated, and when the charge of the photoelectric conversion unit in the same row also becomes saturated, the charge moves to the floating diffusion FD. PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The magnitude relationship between OF2 and OF3 can be realized by adjusting the impurity concentrations of the photoelectric conversion units PD1 to PD4, the p-well region pwell, and the impurity layer 30. Vmax , OF3 Vmax The order of magnitude relationship is set depending on whether the pixel 4 is configured to acquire pixel signals from the photoelectric conversion units PD2 and PD4 (the photoelectric conversion units on the left side in FIG. 35) first, or the pixel signals from the photoelectric conversion units PD1 and PD2 (the photoelectric conversion units on the upper side in FIG. 35). Vmax >OF3 Vmax is the order in the case where the pixel signals of the photoelectric conversion units PD2 and PD4 are acquired first.

[0051] In addition, in special pixel 5, PD Vmax , OF2 Vmax , OF3 Vmax and T.G. Vmax The relationship between the magnitudes of PD Vmax >TG Vmax >OF2 Vmax , OF3 VmaxThe order is as follows. That is, the potential of the first overflow path 38, which transfers charge overflowing from the photoelectric conversion units PD to PD4 of the special pixel 5 to the floating diffusion FD, is deeper than the potential of the second overflow path 36, which transfers charge between two photoelectric conversion units aligned in the column direction among the four photoelectric conversion units PD1 to PD4 included in the special pixel 5, and the potential of the third overflow path 37, which transfers charge between two photoelectric conversion units aligned in the row direction. As a result, when the charge of one of the photoelectric conversion units PD1 to PD4 in the special pixel 5 becomes saturated, the charge moves to the floating diffusion FD. This makes it possible to suppress the transfer of charge between the specific photoelectric conversion unit 16 and the photoelectric conversion unit in the same row or column as the specific photoelectric conversion unit 16, thereby suppressing a decrease in the accuracy of the phase difference signal.

[0052] (8) Furthermore, the present technology can be applied to photodetection devices in general, including distance measurement sensors that measure distance, also known as time-of-flight (ToF) sensors, in addition to the light receiving element 106 as the image sensor described above. A distance measurement sensor emits light toward an object, detects the light reflected by the surface of the object, and calculates the distance to the object based on the time of flight between when the light is emitted and when the reflected light is received. The light receiving pixel structure of this distance measurement sensor can employ the structure of pixel 3 described above.

[0053] The present technology may also be configured as follows: (1) A photodetector device including: a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction; a plurality of pixels including two or more of the photoelectric conversion units lined up in the first direction; and a microlens arranged on a light incident surface side of the semiconductor substrate, the microlens concentrating light that has passed through an imaging optical system of an imaging device for each of the pixels, wherein the plurality of pixels include a plurality of special pixels, and the special pixels have a light-shielding film that covers one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units, and at least some of the special pixels are arranged apart from each other in the first direction, and the width in the first direction of the light-shielding film of each special pixel differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers. (2) The photodetector according to (1), wherein, when viewed from a thickness direction of the semiconductor substrate, a width of the light-shielding film in the first direction is such that a light-collecting area of ​​light that has passed through the imaging optical system having a predetermined pupil distance and been collected by the microlens overlaps with an end of the light-shielding film in the first direction. (3) The pixel includes, as the two or more photoelectric conversion units, two of the photoelectric conversion units lined up in the first direction, and the specific photoelectric conversion unit is one of the two photoelectric conversion units included in the special pixel. (4) The specific photoelectric conversion unit is configured into a plurality of photoelectric conversion unit pairs each including a first specific photoelectric conversion unit located on one side of one of the special pixels in the first direction and having one end region of its light incident surface in the first direction covered with the light-shielding film, and a second specific photoelectric conversion unit located on one side of another of the special pixels in the first direction and having the other end region of its light incident surface in the first direction covered with the light-shielding film, and the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film.(5) When viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes: a first light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and a second light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance to overlap with an end of the light-shielding film in the first direction; and the multiple photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film; and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film. (6) The photodetector according to (5), wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are the photoelectric conversion units located on one side of two predetermined special pixels in the first direction as the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the first specific photoelectric conversion unit pair, and the photoelectric conversion units located on the other side of the two special pixels in the first direction as the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the second specific photoelectric conversion unit pair. (7) The photodetector according to any of (3) to (6), further comprising: a first overflow path that transfers charge between the two photoelectric conversion units included in the special pixel; and a second overflow path that transfers charge overflowing from the photoelectric conversion units of the special pixel to a floating diffusion, wherein a potential of the second overflow path is deeper than a potential of the first overflow path. (8) The photodetector according to (1), wherein the pixel includes four photoelectric conversion units arranged in a 2x2 array as the two or more photoelectric conversion units, and the specific photoelectric conversion unit is one pair of the photoelectric conversion units among two pairs of the photoelectric conversion units arranged in the second direction and included in the special pixel.(9) The specific photoelectric conversion unit is configured to form a plurality of photoelectric conversion unit pairs, each pair including two first specific photoelectric conversion units located on one side of one of the special pixels in the first direction and having one end region of the light incident surface in the first direction covered with the light-shielding film, and two second specific photoelectric conversion units located on one side of another of the special pixels in the first direction and having the other end region of the light incident surface in the first direction covered with the light-shielding film, and the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film. (10) When viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes: a first light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and a second light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance to overlap with an end of the light-shielding film in the first direction; and the multiple photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film; and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film. (11) The photodetector device according to (10), wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are each a pair of photoelectric conversion units located on one side of two specific special pixels in the first direction, and the first specific photoelectric conversion unit and the second specific photoelectric conversion unit are each a pair of photoelectric conversion units located on the other side of the two special pixels in the first direction.(12) The photodetector device according to (8), further comprising a signal processing unit that generates a pixel signal by subtracting a second pixel signal, which is a pixel signal of two of the specific photoelectric conversion units located on one side of the special pixel in the first direction and whose light incident surfaces are covered with the light-shielding film, from a first pixel signal, which is a pixel signal of two of the photoelectric conversion units located on one side of the pixel in the first direction and whose light incident surfaces are not covered with the light-shielding film. (13) The photodetector according to any one of (8) to (12), comprising: a first overflow path that transfers charge overflowing from the photoelectric conversion unit of the special pixel to a floating diffusion; a second overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel and that are aligned in the second direction; and a third overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel and that are aligned in the first direction, wherein the second overflow path has the deepest potential, the first overflow path has the second deepest potential, and the third overflow path has the third deepest potential. (14) The photodetector according to (1), wherein the pixel includes four photoelectric conversion units arranged in a 2 x 2 array as the two or more photoelectric conversion units, and the specific photoelectric conversion unit is one of the four photoelectric conversion units included in the special pixel. (15) The specific photoelectric conversion unit is configured into a plurality of photoelectric conversion unit pairs, each pair including a first specific photoelectric conversion unit located on one side of one of the special pixels in the first direction and having one end region of its light incident surface in the first direction covered with the light-shielding film, and a second specific photoelectric conversion unit located on one side of another of the special pixels in the first direction and having the other end region of its light incident surface in the first direction covered with the light-shielding film, and the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film.(16) When viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes: a first light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and a second light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance to overlap with an end of the light-shielding film in the first direction; and the plurality of photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film; and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film. (17) The photodetector according to any one of (16) to (17), wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are each one of a pair of photoelectric conversion units located on one side of two predetermined special pixels in the second direction as the first specific photoelectric conversion unit of the first specific photoelectric conversion unit pair, and the second specific photoelectric conversion unit of a pair of photoelectric conversion units located on the other side of the two special pixels in the second direction as the first specific photoelectric conversion unit of the second specific photoelectric conversion unit pair. (18) The photodetector according to any one of (14) to (17), wherein the shape of the light-shielding film is rectangular or trapezoidal when viewed from a thickness direction of the semiconductor substrate. (19) The photodetector according to (1), wherein the pixel includes four photoelectric conversion units arranged in a 2 × 2 array as the two or more photoelectric conversion units, and the special pixel further has a second direction light-shielding film covering one end region or the other end region in the second direction of the light incident surface of the specific photoelectric conversion unit. (20) The photodetector according to (19), wherein, when viewed in a thickness direction of the semiconductor substrate, the width in the second direction of the second direction light-shielding film is sized so that a light-collecting region of light that has passed through the imaging optical system having a predetermined pupil distance and is collected by the microlens overlaps with an end of the light-shielding film in the second direction.(21) The photodetector according to (19) or (20), comprising: a first overflow path that transfers charge overflowing from the photoelectric conversion unit of the special pixel to a floating diffusion, a second overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel and that are aligned in the second direction, and a third overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel and that are aligned in the first direction, wherein a potential of the first overflow path is deeper than a potential of the second overflow path and the third overflow path. (22) The photodetector according to any of (1) to (21), wherein, when viewed in a thickness direction of the semiconductor substrate, the microlens is disposed at a pupil-corrected position such that a light-collecting area of ​​light that passes through the imaging optical system having a predetermined pupil distance and is collected by the microlens overlaps with the center of the pixel. (23) An imaging device comprising: a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction; a plurality of pixels including two or more of the photoelectric conversion units lined up in the first direction; and a microlens arranged on the light incident surface side of the semiconductor substrate and configured to focus light that has passed through the imaging optical system of the imaging device for each pixel, wherein the plurality of pixels include a plurality of special pixels, and the special pixels have a light-shielding film that covers one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units, and at least some of the special pixels are arranged apart from each other in the first direction, and a light-detecting device in which the width in the first direction of the light-shielding film of each special pixel differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers.

[0054] 1...Semiconductor substrate, 2...Pixel region, 3...Pixel, 4...Normal pixel, 5...Special pixel, 6...First block, 7...Second block, 8...Block pair, 9...First group, 10...Second group, 11...Third group, 12...First pixel group, 13...Second pixel group, 14...Microlens, 15...Light-shielding film, 16...Specific photoelectric conversion unit, 17...Photoelectric conversion unit pair, 18...First specific photoelectric conversion unit, 19...Second specific photoelectric conversion unit, 20...First light-shielding film, 21...Second light-shielding film, 22...First specific photoelectric conversion unit pair, 23...Second specific photoelectric conversion unit pair, 24...Pixel separation structure, 25...Inter-pixel separation unit, 26...Intra-pixel separation unit, 27...Trench portion, 28...Fixed charge film, 29...Insulating film, 30...Impurity layer, 31...First overflow Low pass, 32...transfer transistor, 33...gate insulating film, 34...gate electrode, 35...second overflow path, 36...second overflow path, 37...third overflow path, 38...first overflow path, 40...pinhole pixel, 41...pinhole light-shielding film, 42...island light-shielding film, 43...island pixel, 44...first intersection, 45...second intersection, 46...third intersection, 50...second light-shielding film, 51...second light-shielding film, 52...first specified photoelectric conversion unit, 53...second specified photoelectric conversion unit, 54...color filter, 55...exit pupil, 100...imaging device, 101...camera lens, 102...solid-state imaging device, 103...control unit, 104...storage unit, 105...monitor, 106...light-receiving element, 107...signal processing unit

Claims

1. A photodetection device comprising: a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction; a plurality of pixels including two or more of the photoelectric conversion units lined up in the first direction; and a microlens arranged on the light incident surface side of the semiconductor substrate and configured to collect light that has passed through the imaging optical system of the imaging device for each pixel, wherein the plurality of pixels include a plurality of special pixels, each of the special pixels having a light-shielding film covering one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units, and at least some of the special pixels are arranged apart from each other in the first direction, and the width in the first direction of the light-shielding film of each of the special pixels differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers.

2. The optical detection device described in claim 1, wherein, when viewed from the thickness direction of the semiconductor substrate, the width of the light-shielding film in the first direction is sized so that a focusing area of ​​light that passes through the imaging optical system having a predetermined pupil distance and is focused by the microlens overlaps with an end of the light-shielding film in the first direction.

3. The optical detection device according to claim 1, wherein the pixel includes two photoelectric conversion units arranged in the first direction as the two or more photoelectric conversion units, and the specific photoelectric conversion unit is one of the two photoelectric conversion units included in the special pixel.

4. The photodetection device of claim 3, wherein the specific photoelectric conversion unit is configured as a plurality of photoelectric conversion unit pairs including a first specific photoelectric conversion unit located on one side of the first direction of one of the special pixels and having one end region of its light incident surface in the first direction covered with the light-shielding film, and a second specific photoelectric conversion unit located on one side of the first direction of another of the special pixels and having the other end region of its light incident surface in the first direction covered with the light-shielding film, and wherein the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film.

5. The light detection device of claim 4, wherein, when viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes a first light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction, and a second light-shielding film having a width in the first direction that is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and the multiple photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film, and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film.

6. The light detection device described in claim 5, wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are each configured as the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the first specific photoelectric conversion unit pair by the photoelectric conversion units located on one side of the first direction of two specific special pixels, and the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the second specific photoelectric conversion unit pair are each configured as the photoelectric conversion units located on the other side of the two special pixels in the first direction.

7. A photodetection device as described in claim 3, comprising: a first overflow path for transferring electric charges between the two photoelectric conversion units included in the special pixel; and a second overflow path for transferring electric charges overflowing from the photoelectric conversion unit of the special pixel to a floating diffusion, wherein the potential of the second overflow path is deeper than the potential of the first overflow path.

8. The photodetection device according to claim 1, wherein the pixel includes four photoelectric conversion units arranged in a 2 x 2 array as the two or more photoelectric conversion units, and the specific photoelectric conversion unit is a pair of the photoelectric conversion units out of two pairs of the photoelectric conversion units arranged in the second direction included in the special pixel.

9. The photodetection device of claim 8, wherein the specific photoelectric conversion unit is configured to include a plurality of photoelectric conversion unit pairs each including two first specific photoelectric conversion units located on one side of one of the special pixels in the first direction and having one end region of the light incident surface in the first direction covered with the light-shielding film, and two second specific photoelectric conversion units located on one side of the first direction of another of the special pixels and having the other end region of the light incident surface in the first direction covered with the light-shielding film, and wherein the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film.

10. The light detection device of claim 9, wherein, when viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes a first light-shielding film whose width in the first direction is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction, and a second light-shielding film whose width in the first direction is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and the multiple photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film, and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film.

11. The light detection device described in claim 10, wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are each a pair of photoelectric conversion units located on one side of the first direction of two specific special pixels, the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the first specific photoelectric conversion unit pair, and each a pair of photoelectric conversion units located on the other side of the two special pixels in the first direction, the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the second specific photoelectric conversion unit pair.

12. The photodetection device according to claim 8, further comprising a signal processing unit that generates a pixel signal by subtracting a second pixel signal, which is a pixel signal of two of the specific photoelectric conversion units located on one side of the special pixel in the first direction and whose light incident surfaces are covered with the light-shielding film, from a first pixel signal, which is a pixel signal of two of the photoelectric conversion units located on one side of the pixel in the first direction and whose light incident surfaces are not covered with the light-shielding film.

13. A photodetection device as described in claim 8, comprising: a first overflow path that transfers charge overflowing from the photoelectric conversion unit of the special pixel to a floating diffusion; a second overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel that are aligned in the second direction; and a third overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel that are aligned in the first direction, wherein the potential of the second overflow path is the deepest, the potential of the first overflow path is the second deepest, and the potential of the third overflow path is the third deepest.

14. The optical detection device according to claim 1, wherein the pixel includes four photoelectric conversion units arranged in a 2 x 2 array as the two or more photoelectric conversion units, and the specific photoelectric conversion unit is one of the four photoelectric conversion units included in the special pixel.

15. The light detection device described in claim 14, wherein the specific photoelectric conversion unit is configured as a plurality of photoelectric conversion unit pairs including a first specific photoelectric conversion unit located on one side of the first direction of one of the special pixels and having one end region of its light incident surface in the first direction covered with the light-shielding film, and a second specific photoelectric conversion unit located on one side of the first direction of another of the special pixels and having the other end region of its light incident surface in the first direction covered with the light-shielding film, and wherein the width in the first direction of the light-shielding film covering the light incident surface of the first specific photoelectric conversion unit included in the same photoelectric conversion unit pair is equal to the width in the first direction of the region of the light incident surface of the second specific photoelectric conversion unit that is not covered with the light-shielding film.

16. The light detection device described in claim 15, wherein, when viewed from the thickness direction of the semiconductor substrate, the light-shielding film includes a first light-shielding film whose width in the first direction is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a predetermined first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction, and a second light-shielding film whose width in the first direction is large enough to allow a focusing area of ​​light that passes through the imaging optical system having a second pupil distance different from the first pupil distance and is focused by the microlens to overlap with an end of the light-shielding film in the first direction; and the multiple photoelectric conversion unit pairs include a first specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the first light-shielding film, and a second specific photoelectric conversion unit pair in which the light-shielding film covering the light incident surfaces of the first specific photoelectric conversion unit and the second specific photoelectric conversion unit is the second light-shielding film.

17. The light detection device described in claim 16, wherein the first specific photoelectric conversion unit pair and the second specific photoelectric conversion unit pair are each configured as the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the first specific photoelectric conversion unit pair, respectively, of one of a pair of photoelectric conversion units located on one side of the second direction of two specific special pixels, and the first specific photoelectric conversion unit and the second specific photoelectric conversion unit of the second specific photoelectric conversion unit pair, respectively, of one of a pair of photoelectric conversion units located on the other side of the two special pixels in the second direction.

18. The photodetector according to claim 14, wherein the light-shielding film has a rectangular or trapezoidal shape when viewed in the thickness direction of the semiconductor substrate.

19. The photodetection device of claim 1, wherein the pixel includes four photoelectric conversion units arranged in a 2 x 2 array as the two or more photoelectric conversion units, and the special pixel further has a second direction light-shielding film covering one end side region or the other end side region in the second direction of the light incident surface of the specific photoelectric conversion unit.

20. The optical detection device described in claim 19, wherein, when viewed from the thickness direction of the semiconductor substrate, the width of the second direction of the second direction light-shielding film is sized so that a focusing area of ​​light that passes through the imaging optical system having a predetermined pupil distance and is focused by the microlens overlaps with an end of the second direction light-shielding film in the second direction.

21. A photodetection device as described in claim 19, comprising: a first overflow path that transfers charge overflowing from the photoelectric conversion unit of the special pixel to a floating diffusion; a second overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel that are aligned in the second direction; and a third overflow path that transfers charge between two of the four photoelectric conversion units included in the special pixel that are aligned in the first direction, wherein the potential of the first overflow path is deeper than the potential of the second overflow path and the third overflow path.

22. The optical detection device according to claim 1, wherein, when viewed in the thickness direction of the semiconductor substrate, the microlens is arranged at a pupil-corrected position so that the focusing area of ​​light that passes through the imaging optical system having a predetermined pupil distance and is focused by the microlens overlaps with the center of the pixel.

23. An imaging device comprising: a semiconductor substrate including a plurality of photoelectric conversion units arranged in an array in a first direction and a second direction; a plurality of pixels including two or more of the photoelectric conversion units lined up in the first direction; and a microlens arranged on the light incident surface side of the semiconductor substrate and configured to focus light that has passed through an imaging optical system of the imaging device for each of the pixels, wherein the plurality of pixels include a plurality of special pixels, each of which has a light-shielding film covering one end side region or the other end side region in the first direction of the light incident surface of a specific photoelectric conversion unit that is at least a part of the two or more photoelectric conversion units, wherein at least some of the special pixels are arranged apart from each other in the first direction, and wherein the width in the first direction of the light-shielding film of each of the special pixels differs depending on the image height in the first direction of the specific photoelectric conversion unit that the light-shielding film covers.

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