An image sensor

Abstract

The application provides an image sensor, which comprises: a pixel array comprising a plurality of pixels; a phase focusing module, which is arranged in the pixel array and comprises a plurality of pixels; and a focusing pixel unit, which comprises at least one pixel and is arranged in pairs in the phase focusing module, and in each focusing pixel unit, a boundary line between a metal shielding area and a light-transmitting area is perpendicular to a light vector. The image sensor provided by the application can improve the focusing effect of the image sensor.

Description

Technical Field

[0001] This invention belongs to the field of electronic circuit technology, and specifically relates to an image sensor. Background Technology

[0002] In recent years, Complementary Metal Oxide Semiconductor (CMOS) image sensors have been widely used in various fields. Many digital cameras have autofocus capabilities. Autofocus is achieved through contrast detection autofocus (CDAF), which detects the sharpness of the image and then continuously moves a motor back and forth to achieve focus. However, because it requires constant motor movement for focus comparison, contrast detection autofocus takes a relatively long time. Phase detection autofocus (PDAF), due to its short focusing time, is gaining increasing attention.

[0003] The phase-detection autofocus module is directly built onto the image sensor chip. By setting a left and right metal mask pair in the pixel array, it can calculate the focus position of the entire image and ultimately obtain the distance and direction of the motor displacement. However, because the chief ray angle (CRA) varies at different positions on the image sensor, the phase-detection autofocus sensitivity of the left and right metal mask pairs also differs, affecting the focusing performance of the image sensor. Summary of the Invention

[0004] The purpose of this invention is to provide an image sensor that can improve the focusing effect of the image sensor.

[0005] To achieve the above objectives, the present invention provides an image sensor comprising at least:

[0006] A pixel array, comprising multiple pixels;

[0007] Phase detection autofocus modules are distributed within the pixel array, and the phase detection autofocus module includes multiple pixels; and

[0008] The focusing pixel unit includes at least one pixel, and the focusing pixel units are arranged in pairs in the phase focusing module. In each focusing pixel unit, the boundary line between the metal shielding area and the light-transmitting area is perpendicular to the light vector.

[0009] In one embodiment of the present invention, in the focusing pixel unit, the photoelectric sensing area covered by the extended metal grille forms the metal shielding area, and the photoelectric sensing area not covered by the extended metal grille forms the light-transmitting area.

[0010] In one embodiment of the present invention, in the two arrangement directions of the pixel array, the spacing between adjacent phase focusing modules is equal to the number of pixels.

[0011] In one embodiment of the present invention, one of the metal-shielded areas is located on the side of one of the focusing pixel units closer to the center of the pixel array, and the other metal-shielded area is located on the side of another focusing pixel unit farther from the center of the pixel array.

[0012] In one embodiment of the present invention, the area of ​​the metal shielding region is equal to the area of ​​the light-transmitting region, and is 50% of the focusing pixel unit.

[0013] In one embodiment of the present invention, in a pair of focusing pixel units, when the angle of the principal optical axis is 0°, the area of ​​the metal shielding area is equal to the area of ​​the light-transmitting area, and is 50% of the focusing pixel unit.

[0014] In one embodiment of the present invention, in a pair of focusing pixel units, as the angle of the principal optical axis increases, the area difference between the area of ​​the metal shielding region and the area of ​​the light-transmitting region increases.

[0015] In one embodiment of the present invention, each focusing pixel unit includes one pixel.

[0016] In one embodiment of the present invention, each focusing pixel unit includes a plurality of pixels, and in each pixel, a metal shielding area and a light-transmitting area are provided, and the boundary line between each metal shielding area and the light-transmitting area is perpendicular to the light vector.

[0017] In one embodiment of the present invention, each focusing pixel unit includes multiple pixels, and in one focusing pixel unit, a metal shielding area and a light-transmitting area are provided, and the boundary line between the metal shielding area and the light-transmitting area is perpendicular to the light vector.

[0018] In summary, the image sensor provided by this invention does not require additional photomasks or processes under the same focusing pixel unit density. By designing different metal shielding areas at different positions, the angular sensitivity error of the left and right parts and the top and bottom parts of the pixel array is reduced, thereby improving the overall angular sensitivity of the pixel array and enhancing the focusing effect of the image sensor. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a top view of an image sensor according to one embodiment of this application.

[0021] Figure 2 This is the structure of pixels and focusing pixel units in a back-illuminated image sensor according to one embodiment of this application.

[0022] Figure 3 This is the structure of pixels and focus pixel units in a back-illuminated image sensor with an embedded color filter layer in one embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the arrangement of the focusing pixel units in one embodiment.

[0024] Figure 5 This is a schematic diagram of the arrangement of the focusing pixel units in one embodiment of this application.

[0025] Figure 6 This application Figure 5 The image shows a schematic diagram of a phase focusing module.

[0026] Figure 7 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 0°.

[0027] Figure 8 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 15°.

[0028] Figure 9 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 30°.

[0029] Figure 10 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 45°.

[0030] Figure 11 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 60°.

[0031] Figure 12 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 75°.

[0032] Figure 13 This is a comparison of the angular sensitivity of the image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array when the light vector is 90°.

[0033] Figure 14 This is a structural diagram of the focusing pixel unit when the angle of the principal optical axis is different in one embodiment of this application.

[0034] Figure 15 This is a schematic diagram of the structure of a focusing pixel unit with four pixels in one embodiment of this application, where each pixel has a metal shielding area and a light-transmitting area.

[0035] Figure 16 This is a schematic diagram of the structure of a focusing pixel unit with four pixels in one embodiment of this application, and the focusing pixel unit has a metal shielding area and a light-transmitting area.

[0036] Label Explanation:

[0037] 100. Pixel array; 101. Pixel; 102. Phase focusing module; 103. Focusing pixel unit; 201. Substrate; 202. Photoelectric sensing area; 203. Shallow trench isolation structure; 204. Dielectric layer; 2041. High dielectric constant material layer; 2042. Oxide layer; 2043. Nitride layer; 205. Metal grid; 2051. Silicon oxide; 206. Isolation layer; 207. Color filter layer; 208. Planarization layer; 209. Microlens; 210. Transmitting area; 211. Metal shielding area; 212. Transmitting layer; A. The angle between the boundary line between the metal shielding area and the transmitting area and the light vector. Detailed Implementation

[0038] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0040] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," and "right," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Phase detection autofocus works by reserving some masked pixels on the image sensor specifically for phase detection. By detecting the sensitivity of a pair of focusing pixels, it determines the focus offset value, thus achieving fast focusing. To make the structure more compact, the phase detection autofocus module 102 can be mounted on the image sensor. This application provides an image sensor with a phase detection autofocus module 102.

[0042] like Figure 1 As shown, Figure 1 This is a top view of an image sensor according to one embodiment of this application. The image sensor has multiple pixels 101 arranged in an array to form a pixel array 100. An external object is projected onto the pixel array 100 through a lens. When focused, the image of the object can be clearly projected onto the pixel array 100. At this time, all incident light is incident on the corresponding pixel 101 along the principal optical axis angle corresponding to each pixel 101. However, when out of focus, the incident light will deflect along the light vector direction shown in the figure, thereby projecting onto multiple pixels 101. For example, Figure 1 As shown by the dashed lines, the light vectors are radial and radiate from the center of the pixel array 100 towards the edges. Furthermore, the light vector on each focusing pixel unit 103 lies on the line connecting the center of the pixel array 100 and the center of the focusing pixel unit 103.

[0043] like Figure 2 As shown, Figure 2This application describes the structure of a pixel and a focusing pixel unit in a back-illuminated image sensor. Each pixel 101 includes a photosensitive area 202, a color filter layer 207, and a microlens 209 disposed on the photosensitive area 202. Specifically, a photosensitive area 202 is disposed in a substrate 201. This photosensitive area 202 can be formed by implanting ions into the substrate 201, and the formed photosensitive area 202 can convert light signals into electrical signals. Shallow trench isolation structures 203 can be disposed between adjacent photosensitive areas 202 to isolate them. A dielectric layer 204 is also disposed on the substrate 201, the dielectric layer 204 including a high dielectric constant material layer 2041, an oxide layer 2042, and a nitride layer 2043. The high dielectric constant material layer 2041 is, for example, a hafnium oxide layer, an aluminum oxide layer, or a tantalum oxide layer; the oxide layer 2042 is, for example, a silicon oxide layer; and the nitride layer 2043 is, for example, a silicon nitride layer. A metal grid 205 is provided on the dielectric layer 204, positioned between adjacent pixels 101 to prevent crosstalk of incident light between adjacent pixels 101. In each pixel 101, the metal grid 205 only covers the area between adjacent photosensitive areas 202, and silicon oxide 2051 is used to isolate adjacent metal grids 205. An isolation layer 206, for example, a silicon nitride layer, is provided on the metal grid 205. A color filter layer 207 is also provided on the isolation layer 206. Each adjacent pixel 101 may contain at least three primary color filter layers 207, for example, a red filter layer, a green filter layer, and a blue filter layer are provided in adjacent pixels 101 respectively. A planarization layer 208 and a microlens 209 are disposed on the color filter layer. The refractive index of the microlens 209 can be appropriately varied according to the optical requirements of the image sensor. The microlens 209 can focus light onto the photoelectric sensing area 202, and the curvature of the surface of the microlens 209 structure can be changed according to the light focusing requirements.

[0044] like Figure 2 As shown, in some embodiments, the structure of the focusing pixel unit 103 is substantially the same as that of the pixel 101. In the focusing pixel unit 103, the metal grille 205 extends upward toward the photoelectric sensing area 202, covering a portion of the photoelectric sensing area 202. In the focusing pixel unit 103, the photoelectric sensing area 202 not covered by the extended metal grille 205 forms a light-transmitting area 210, and the photoelectric sensing area 202 covered by the extended metal grille 205 forms a metal-shielded area 211. In the focusing pixel unit 103, a light-transmitting layer 212 is used instead of the color filter layer 207, and the light-transmitting layer 212 is made of resin, for example, polyimide.

[0045] like Figure 3 As shown, Figure 3This application describes the structure of pixels and focus pixel units in a back-illuminated image sensor with an embedded color filter layer. It is related to... Figure 2 The image sensor area is located between the metal grids 205 and the color filter layer 207. Specifically, a photosensitive region 202 is provided in the substrate 201. This photosensitive region 202 can be formed by implanting ions into the substrate 201, and the formed photosensitive region 202 can convert light signals into electrical signals. A shallow trench isolation structure 203 can be provided between adjacent photosensitive regions 202 to isolate them. A dielectric layer 204 is also provided on the substrate 201, which includes a high dielectric constant material layer 2041, an oxide layer 2042, and a nitride layer 2043. The high dielectric constant material layer 2041 is, for example, a hafnium oxide layer, an aluminum oxide layer, or a tantalum oxide layer; the oxide layer 2042 is, for example, a silicon oxide layer; and the nitride layer 2043 is, for example, a silicon nitride layer. A metal grid 205 is disposed on the dielectric layer 204, between adjacent pixels 101, to prevent crosstalk of incident light between adjacent pixels 101. In each pixel 101, the metal grid 205 only covers the area between adjacent photosensitive areas 202. A color filter layer 207 is disposed between adjacent metal grids 205. Each adjacent pixel 101 may contain at least three primary color filter layers 207, for example, a red filter layer, a green filter layer, and a blue filter layer are disposed in adjacent pixels 101. A planarization layer 208 and a microlens 209 are disposed on the color filter layer. The refractive index of the microlens 209 can be appropriately varied according to the optical requirements of the image sensor. The microlens 209 can focus light onto the photosensitive area 202, and the curvature of the surface of the microlens 209 structure can be changed according to the light-gathering requirements.

[0046] like Figure 3 As shown, in some embodiments, the structure of the focusing pixel unit 103 is substantially the same as that of the pixel 101. In the focusing pixel unit 103, the metal grille 205 extends upward toward the photoelectric sensing area 202, covering a portion of the photoelectric sensing area 202. In the focusing pixel unit 103, the photoelectric sensing area 202 not covered by the extended metal grille 205 forms a light-transmitting area 210, and the photoelectric sensing area 202 covered by the extended metal grille 205 forms a metal-shielded area 211. In the focusing pixel unit 103, a light-transmitting layer 212 is used instead of the color filter layer 207, and the light-transmitting layer 212 is made of resin, for example, polyimide.

[0047] like Figure 5As shown, in one embodiment of this application, a plurality of phase focusing modules 102 are provided in the pixel array 100. The phase focusing module 102 includes a plurality of pixels 101 and at least one pair of focusing pixel units 103. In this application, the phase focusing modules 102 are evenly distributed in the pixel array 100, that is, one phase focusing module 102 is provided at equal intervals of a number of pixels 101 in both arrangement directions of the pixel array 100.

[0048] like Figures 5 to 6 As shown, in one embodiment of this application, a phase focusing module 102 is provided with at least a pair of focusing pixel units 103, and each focusing pixel unit 103 includes at least one pixel 101. In this embodiment, each focusing pixel unit 103 includes, for example, one pixel 101, and in each focusing pixel unit 103, the boundary line between the metal shielding region 211 and the light-transmitting region 210 is perpendicular to the light vector, that is, the angle A formed by the boundary line between the metal shielding region 211 and the light-transmitting region 210 and the light vector is 90°. In this application, in a pair of focusing pixel units 103, the two metal shielding regions 211 are arranged opposite to each other, that is, in one focusing pixel unit 103, the metal shielding region 211 is located on the side of the focusing pixel unit 103 closer to the center of the pixel array, and in the other focusing pixel unit 103, the metal shielding region 211 is located on the side of the focusing pixel unit 103 away from the center of the pixel array. Furthermore, the sum of the areas of the metal-shaded regions 211 in the two focusing pixel units 103 is equal to the area of ​​one focusing pixel unit 103.

[0049] like Figure 4 As shown, in some other embodiments, some conventional image sensors use left and right metal shielding pairs instead of ordinary metal mesh in the pixel array 100 at regular intervals, so that the corresponding pixels can detect light from the left or right side of the lens and realize the function of autofocus pixels. Since the focusing pixel units 103 in the entire pixel array 100 all use left and right metal shielding, the sensitivity of the focusing pixel units 103 on the left and right sides of the pixel array 100 is better, while the sensitivity of the top and bottom corners is worse.

[0050] like Figures 5 to 6 As shown, in this application, the area of ​​the metal-shielded area 211 and the area of ​​the light-transmitting area 210 in each focusing pixel unit 103 are not limited. In this embodiment, in each focusing pixel unit 103, the area of ​​the metal-shielded area 211 and the area of ​​the light-transmitting area 210 are fixed values, and the area of ​​the metal-shielded area 211 is equal to the area of ​​the light-transmitting area 210, which is 50% of the area of ​​the pixel 101 alignment unit.

[0051] like Figures 7 to 13 As shown, Figures 7 to 13This is a comparison of the angular sensitivity of an image sensor in this application, where the boundary between the metal-shaded area and the light-transmitting area is perpendicular to the light vector, and a traditional image sensor with only left and right metal shielding, in different areas of the pixel array. Figures 7 to 13 The figure shows the angular sensitivity response of autofocus pixels along light vector directions at angles of, for example, 0°, 15°, 30°, 45°, 60°, 75°, and 90° to the horizontal. In the figure, the horizontal axis represents the light incident angle, and the vertical axis represents the normalized pixel sensitivity. The two response curves represent the angular response of a pair of phase-focusing pixels at adjacent positions. As can be seen from the figure, in traditional image sensors, as the angle between the light vector and the horizontal direction increases, the angular sensitivity decreases (corresponding to the decreasing difference in the vertical axis between the two response curves at a constant horizontal angle), and the pixel sensitivity decreases further during focusing (corresponding to the decreasing normalized sensitivity when the two curves intersect (horizontal angle is 0)). However, in the image sensor of this invention, the angular sensitivity and focusing sensitivity are almost unrelated to this angle. Because when the boundary between the occlusion and transmission is perpendicular to the light vector, the influence of the light vector direction on the angular sensitivity is eliminated. Therefore, the image sensor provided in this application improves the overall angular sensitivity of the image during phase focusing.

[0052] like Figures 2 to 6 ,as well as Figure 14As shown, in some embodiments, the area of ​​the metal-shielded region 211 and the area of ​​the light-transmitting region 210 are not fixed in different focusing pixel units 103. Furthermore, the areas of the metal-shielded region 211 and the light-transmitting region 210 are related to the principal optical axis angle. When the principal optical axis angle is 0°, light is incident perpendicularly on the metal grid. In this pair of focusing pixel units 103, the areas of the metal-shielded region 211 and the light-transmitting region 210 are equal, and both are 50% of the focusing pixel unit 103, thus ensuring consistent angular sensitivity response of this pair of focusing pixels 101. When the principal optical axis angle is not 0°, for example, 10°, 20°, and 30° are used in this application. As the principal optical axis angle increases, the angle between the incident normals also increases. To ensure that the light spot reaching the silicon surface falls at the center of pixel 101, the microlens 209, the color filter layer 207, and the metal grid 205 will all be displaced. However, because the incident light rays are obliquely incident on the photoelectric sensing area 202, and the microlens 209 has height (i.e., spherical aberration), the energy distribution of the light spot will be closer to the center of the pixel array 100 when passing through the metal grid 205. In order to match the sensitivity responses of this pair of focusing pixel units 103, if the side of the focusing pixel unit 103 closer to the pixel array center 100 is a metal-shielded area 211, then according to simulation results, the area of ​​the metal-shielded area 211 will be designed to gradually decrease. Conversely, if the side of the focusing pixel unit 103 farther from the pixel center is a metal-shielded area 211, then according to simulation results, the area of ​​the metal-shielded area 211 will be designed to gradually increase. That is, in this pair of focusing pixel units 103, the area difference of the metal-shielded areas 211 will increase as the angle of the principal optical axis increases. Ultimately, this makes the angular sensitivity of this pair of focusing pixels 101 comparable.

[0053] like Figure 15 As shown, in some embodiments, each focusing pixel unit 103 includes a plurality of pixels 101. In this embodiment, in a pair of focusing pixel units 103, each focusing pixel unit 103 includes, for example, four pixels 101. Each pixel 101 has a metal shielding region 211 and a light-transmitting region 210, and the boundary line between each metal shielding region 211 and the light-transmitting region 210 is perpendicular to the light vector. In the paired focusing pixel units 103, the number of pixels 101 is equal and the arrangement is the same, with the metal shielding regions 211 and the light-transmitting regions 210 facing each other.

[0054] like Figure 15As shown, in other embodiments, each focusing pixel unit 103 includes, for example, 2, 6, or 8 pixels 101, and this application does not impose any limitations on this. Each pixel 101 is provided with a metal shielding region 211 and a light-transmitting region 210, and the boundary line between each metal shielding region 211 and the light-transmitting region 210 is perpendicular to the light vector. In the paired focusing pixel units 103, the number of pixels 101 in the two focusing pixel units 103 is equal, the arrangement is the same, and the metal shielding regions 211 are arranged opposite to each other, and the light-transmitting regions 210 are arranged opposite to each other.

[0055] like Figure 16 As shown, in some embodiments, each focusing pixel unit 103 includes a plurality of pixels 101. In this embodiment, in a pair of focusing pixel units 103, each focusing pixel unit 103 includes, for example, four pixels 101. Furthermore, in one focusing pixel unit 103, a metal shielding region 211 and a light-transmitting region 210 are provided, and the boundary line between the metal shielding region 211 and the light-transmitting region 210 is perpendicular to the light vector. In the paired focusing pixel units 103, the number of pixels 101 is equal and the arrangement is the same, and the metal shielding regions 211 and 210 are arranged opposite each other.

[0056] like Figure 16 As shown, in other embodiments, each focusing pixel unit 103 includes, for example, 2, 6, or 8 pixels 101, and this application does not impose any limitations on this. In a focusing pixel unit 103, a metal shielding region 211 and a light-transmitting region 210 are provided, and the boundary line between the metal shielding region 211 and the light-transmitting region 210 is perpendicular to the light vector. In the paired focusing pixel units 103, the number of pixels 101 in the two focusing pixel units 103 is equal, the arrangement is the same, and the metal shielding regions 211 and 210 are arranged opposite each other.

[0057] In summary, the image sensor provided by this invention includes a substrate, photosensitive areas disposed in the substrate, shallow trench isolation structures disposed between adjacent photosensitive areas, a dielectric layer disposed on the substrate, a metal grid disposed on the dielectric layer, with the metal grids disposed between adjacent pixels, and a planarization layer and microlenses disposed between adjacent metal grids on a color filter layer. The image sensor also includes a focusing pixel unit. In the pixel focusing unit, the metal grid covers a portion of the photosensitive area, forming a metal-masked area, while the uncovered photosensitive area forms a light-transmitting area, and the boundary line between the metal-masked area and the light-transmitting area is perpendicular to the light vector.

[0058] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An image sensor, characterized in that, At least including: A pixel array, comprising multiple pixels; A phase-detection autofocus module is distributed in the pixel array, and the phase-detection autofocus module includes multiple pixels; as well as The focusing pixel unit includes at least one pixel, and the focusing pixel units are arranged in pairs in the phase focusing module. In each focusing pixel unit, the boundary line between the metal shielding area and the light-transmitting area is perpendicular to the light vector.

2. An image sensor according to claim 1, characterized in that, In the focusing pixel unit, the photoelectric sensing area covered by the extended metal grille forms the metal shielding area, and the photoelectric sensing area not covered by the extended metal grille forms the light-transmitting area.

3. An image sensor according to claim 1, characterized in that, In the two arrangement directions of the pixel array, the spacing between adjacent phase focusing modules is equal in number of pixels.

4. An image sensor according to claim 1, characterized in that, In a pair of focusing pixel units, one of the metal-masked areas is located on the side of one focusing pixel unit closer to the center of the pixel array, and the other metal-masked area is located on the side of the other focusing pixel unit farther from the center of the pixel array.

5. An image sensor according to claim 1, characterized in that, The area of ​​the metal shielding region is equal to the area of ​​the light-transmitting region, and is 50% of the area of ​​the focusing pixel unit.

6. An image sensor according to claim 1, characterized in that, In a pair of focusing pixel units, when the angle of the principal optical axis is 0°, the area of ​​the metal shielding region is equal to the area of ​​the light-transmitting region, and is 50% of the focusing pixel unit.

7. An image sensor according to claim 1, characterized in that, In a pair of focusing pixel units, as the angle of the principal optical axis increases, the difference between the area of ​​the metal-shielded region and the area of ​​the light-transmitting region increases.

8. An image sensor according to claim 1, characterized in that, Each of the focusing pixel units comprises one pixel.

9. An image sensor according to claim 1, characterized in that, Each of the focusing pixel units includes multiple pixels, and in each pixel, there is a metal shielding area and a light-transmitting area, and the boundary line between each metal shielding area and the light-transmitting area is perpendicular to the light vector.

10. An image sensor according to claim 9, characterized in that, Each of the focusing pixel units includes multiple pixels, and in a focusing pixel unit, there is a metal shielding area and a light-transmitting area, and the boundary line between the metal shielding area and the light-transmitting area is perpendicular to the light vector.

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