Image sensor and manufacturing method thereof

Abstract

The invention belongs to the technical field of semiconductors, and discloses an image sensor and a manufacturing method thereof. The photoelectric sensing areas are arranged on the substrate, the isolation structures are arranged between the adjacent photoelectric sensing areas on the substrate, and each isolation structure is a grating structure which is formed by stacking a plurality of material layers and has a light blocking effect; the light filtering element is arranged on the photoelectric sensing area; and the grating is arranged on the isolation structure. The imaging performance of the image sensor can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to an image sensor and a method for manufacturing the same. Background Art

[0002] Image sensors are widely used in photography, security systems, smart phones, medical electronics and other fields. They convert light signals into electrical signals by sensing them in the photoelectric sensing area. Existing image sensors usually use silicon dioxide to isolate adjacent photoelectric sensing areas, but the isolation effect is not good. There is signal crosstalk between adjacent photoelectric sensing areas, which adversely affects the imaging performance of the image sensor. Summary of the invention

[0003] In view of the above problems, the present application provides an image sensor and a method for manufacturing the same, aiming to improve the imaging performance of the image sensor.

[0004] According to a first aspect of the present invention, there is provided an image sensor, comprising:

[0005] substrate;

[0006] A photoelectric sensing region disposed on the substrate and an isolation structure disposed between adjacent photoelectric sensing regions on the substrate, wherein the isolation structure is a grid structure having a light-blocking function formed by stacking a plurality of material layers;

[0007] A filter element is arranged on the photoelectric sensing area and a grid is arranged on the isolation structure.

[0008] Optionally, the isolation structure includes a plurality of material layers which are, from bottom to top on the substrate, a high-k dielectric layer, a metal layer, a barrier layer and an oxide layer;

[0009] The photoelectric sensing region includes a plurality of doping layers, and the doping layer in the photoelectric sensing region adjacent to the metal layer in the isolation structure does not contain metal elements.

[0010] Optionally, the plurality of doped layers included in the photoelectric sensing region are divided into a first doped layer group and a second doped layer group, and the first doped layer group and the second doped layer group are stacked;

[0011] The doped layers in the first doped layer group are stacked, and the doped layers in the second doped layer group are alternately arranged along the direction in which the photoelectric sensing regions and the isolation structures are alternately arranged.

[0012] Optionally, the grid includes a high-k dielectric layer, a metal layer and a barrier layer stacked sequentially from bottom to top on the isolation structure.

[0013] According to a second aspect of the present invention, there is provided a method for manufacturing an image sensor, comprising:

[0014] providing a substrate;

[0015] forming a photoelectric sensing region on the substrate and forming an isolation structure between adjacent photoelectric sensing regions on the substrate, wherein the isolation structure is a grid structure with light-blocking function formed by stacking multiple material layers;

[0016] A filter element is formed on the photoelectric sensing area and a grid is formed on the isolation structure.

[0017] Optionally, the isolation structure includes a first deep trench isolation structure, a photoelectric sensing region is formed on the substrate, and an isolation structure is formed between adjacent photoelectric sensing regions on the substrate, including:

[0018] forming a first stacked structure on the surface of the substrate, wherein the first stacked structure includes a plurality of material layers stacked;

[0019] Etching the first stacked structure to form a first groove and the first deep trench isolation structure formed by the first groove and located at a preset position of the isolation structure;

[0020] The photoelectric sensing region including a plurality of doping layers is formed in the first groove.

[0021] Optionally, forming the photoelectric sensing region including a plurality of doped layers in the first groove includes: sequentially forming a plurality of doped layers in the first groove by deposition or epitaxy to form a first doped layer group included in the photoelectric sensing region.

[0022] Optionally, forming the photoelectric sensing region including a plurality of doping layers in the first groove further comprises:

[0023] forming a target doping layer on the surface of the first doping layer group in the first groove by deposition or epitaxy, wherein the target doping layer includes first regions and second regions alternately arranged along a direction in which the photoelectric sensing regions and the isolation structures are alternately arranged;

[0024] The doping elements in the first region are diffused by an annealing process, and a doping element different from that in the second region is implanted into the first region by an ion implantation process to form a second doping layer group included in the photoelectric sensing region.

[0025] Optionally, the isolation structure further includes a second deep trench isolation structure, a photoelectric sensing region is formed on the substrate, and an isolation structure is formed between adjacent photoelectric sensing regions on the substrate, and further includes:

[0026] forming an isolation layer before forming the first stacked structure on the substrate;

[0027] The isolation layer is etched to form the second deep trench isolation structure at a preset position of the isolation structure, wherein a projection of an edge of the first deep trench isolation structure on a surface of the second deep trench isolation structure falls within an edge of the surface of the second deep trench isolation structure.

[0028] Optionally, forming a filter element on the photoelectric sensing area and forming a grid on the isolation structure includes:

[0029] forming a second stacked structure on the surface of the photoelectric sensing region and the surface of the isolation structure;

[0030] Etching the second stacked structure to form a second groove and a grid formed by the second groove and located on the surface of the isolation structure;

[0031] The filter element is formed in the second groove.

[0032] The unexpected technical effects of this application are:

[0033] The image sensor provided by the present application includes: a substrate, a photoelectric sensing area arranged on the substrate and an isolation structure arranged on the substrate between adjacent photoelectric sensing areas, a filter element arranged on the photoelectric sensing area and a grid arranged on the isolation structure, wherein the isolation structure is a grid structure with a light-blocking function formed by stacking multiple material layers, so that the isolation structure can not only prevent crosstalk of electrical signals between adjacent photoelectric sensing areas, but also prevent crosstalk of optical signals between adjacent photoelectric sensing areas, so that the signal crosstalk problem between adjacent photoelectric sensing areas is effectively solved, and the imaging performance of the image sensor can be effectively improved.

[0034] Furthermore, the isolation structure includes multiple material layers that are, from bottom to top on the substrate, a high-k dielectric layer, a metal layer, a barrier layer, and an oxide layer; the photoelectric sensing region includes multiple doping layers, and the doping layer in the photoelectric sensing region adjacent to the metal layer in the isolation structure does not contain metal elements. Therefore, for the isolation structure that needs to include a metal layer to block light, electrons between adjacent photoelectric sensing regions will not flow through the metal layer included in the isolation structure, so that the isolation structure can well balance preventing optical signal crosstalk and preventing electrical signal crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:

[0036] Figure 1 A cross-sectional view of a conventional back-illuminated image sensor is shown;

[0037] Figure 2 A cross-sectional view of an exemplary image sensor in an embodiment of the present application is shown;

[0038] Figure 3 A flow chart showing a method for manufacturing an image sensor in an embodiment of the present application;

[0039] Figure 4a A cross-sectional view of a substrate in an embodiment of the present application is shown;

[0040] Figure 4b A cross-sectional view after an isolation layer is formed on a substrate in an embodiment of the present application is shown;

[0041] Figure 4c A cross-sectional view showing a second deep trench isolation structure formed on a substrate in an embodiment of the present application is shown;

[0042] Figure 4d A cross-sectional view after a first stacked structure is formed on a substrate in an embodiment of the present application is shown;

[0043] Figure 4e A cross-sectional view after a first deep trench isolation structure is formed on a substrate in an embodiment of the present application is shown;

[0044] Figure 4f A cross-sectional view after a first doping layer group is formed in a first groove in an embodiment of the present application is shown;

[0045] Figure 4g A cross-sectional view after a target doping layer is formed in the first groove in an embodiment of the present application is shown;

[0046] Figure 4h A cross-sectional view after a second doping layer group is formed in the first groove in the embodiment of the present application is shown;

[0047] Figure 4i A cross-sectional view showing the surface of the photoelectric sensing region and the surface of the isolation structure after forming a second stacked structure in the embodiment of the present application;

[0048] Figure 4j A cross-sectional view is shown after a grid is formed on the surface of the isolation structure in an embodiment of the present application.

[0049] Description of reference numerals: 111-substrate; 112-deep trench isolation structure; 113-photoelectric sensing region; 114-shallow trench isolation structure; 121-first dielectric layer; 122-second dielectric layer; 123-pad; 124-connection structure; 125-polysilicon structure; 130-mask material layer; 131-first mask layer; 132-second mask layer; 133-third mask layer; 134-fourth mask layer; 140-grid; 201-first dielectric layer; 202-second dielectric layer; 210-substrate; 211-isolation layer; 212-epitaxial layer; 213-shallow trench isolation structure; 220-photoelectric sensing region; 2 21-doping layer; 222-doping layer; 223-doping layer; 224-doping layer; 224'-target doping layer; 225-doping layer; 230-isolation structure; 231-first deep trench isolation structure; 231a-high-k dielectric layer; 231b-metal layer; 231c-barrier layer; 231d-oxide layer; 232-second deep trench isolation structure; 233-first groove; 240-filter element; 241-blue filter element; 242-green filter element; 243-red filter element; 250-grid; 251-high-k dielectric layer; 252-metal layer; 253-barrier layer; 254-second groove. DETAILED DESCRIPTION

[0050] The present application will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown.

[0051] This application may be presented in a variety of forms, some examples of which are described below.

[0052] Figure 1 The figure shows an existing back-illuminated (BSI) image sensor. Figure 1 As shown, the back-illuminated image sensor includes a substrate 111, in which a plurality of photoelectric sensing regions 113 and a deep trench isolation (DTI) structure 112 and a shallow trench isolation (STI) structure 114 are provided for separating adjacent photoelectric sensing regions 113. The material used for the substrate 111 is, for example, silicon (Si), and the material used for the deep trench isolation structure 112 is, for example, silicon oxide (SiO2). The above-mentioned photoelectric sensing region 113 is also called a photodiode (PD), which can be Figure 1The front end of line (FEOL) process shown is formed by implanting ions into the substrate 111 from the bottom surface of the substrate 111 .

[0053] Figure 1 The middle substrate 111 is located on the surface of the second dielectric layer 122, and the second dielectric layer 122 is located on the surface of the first dielectric layer 121. A pad 123 is arranged on the bottom surface of the first dielectric layer 121. The pad 123 is connected to the polysilicon structure 125 arranged in the second dielectric layer 122 through a connection structure 124 arranged in the first dielectric layer 121. The material used by the pad 123 is, for example, copper (Cu). A mask material layer 130 is arranged on the surface of the substrate 111, and a grid 140 formed by stacking different materials is arranged on the surface of the mask material layer 130. The mask material layer 130 includes a first mask layer 131, a second mask layer 132, a third mask layer 133 and a fourth mask layer 134, wherein the materials used by the first mask layer 131 and the fourth mask layer 134 may be silicon oxide, the material used by the second mask layer 132 may be aluminum oxide (Al2O3), and the material used by the third mask layer 133 may be tantalum oxide (Ta2O5). The thickness of the substrate 111 may be 3 um, the thickness of the first mask layer 131 may be 120 angstroms, the thickness of the second mask layer 132 may be 75 angstroms, the thickness of the third mask layer 132 may be 520 angstroms, and the thickness of the fourth mask layer 134 may be 1800 angstroms.

[0054] like Figure 1 As shown, the existing image sensor usually uses silicon oxide to make the deep trench isolation structure 112, the isolation effect between adjacent photoelectric sensing regions 113 is not good, and there is signal crosstalk between adjacent photoelectric sensing regions 113, so that the imaging performance of the existing image sensor is adversely affected.

[0055] In view of this, one embodiment of the present application provides an image sensor. Figure 2 FIG. 1 is a cross-sectional schematic diagram of an exemplary image sensor provided according to an embodiment of the present application, as shown in FIG. Figure 2As shown, the image sensor includes: a substrate 210, a photoelectric sensing region 220 disposed on the substrate 210, an isolation structure 230 disposed between adjacent photoelectric sensing regions 220 on the substrate 210, a filter element 240 disposed on the photoelectric sensing region 220, and a grid 250 disposed on the isolation structure 230. The main improvement of the image sensor in the embodiment of the present application is that the isolation structure 230 adopts a grid structure with a light-blocking function formed by stacking multiple material layers, so that the isolation structure 230 can not only prevent the crosstalk of electrical signals between adjacent photoelectric sensing regions 220, but also prevent the crosstalk of optical signals between adjacent photoelectric sensing regions 220, so that the signal crosstalk problem between adjacent photoelectric sensing regions 220 is effectively solved, and the imaging performance of the image sensor can be effectively improved.

[0056] Figure 2 The isolation structure 230 in the exemplary image sensor shown includes a first deep trench isolation structure 231 and a second deep trench isolation structure 232. The isolation structure 230 uses a grid structure with light-shielding function formed by stacking multiple material layers. This is mainly reflected in that the first deep trench isolation structure 231 is a grid structure with light-shielding function formed by stacking multiple material layers. Specifically, refer to Figure 2 The first deep trench isolation structure 231 includes a high-k dielectric layer 231a, a metal layer 231b, a barrier layer 231c and an oxide layer 231d stacked sequentially from bottom to top on the substrate 210, so that the first deep trench isolation structure 231 includes multiple material layers commonly used by the grid 250, that is, the first deep trench isolation structure 231 includes a composite metal grid (CMG) structure, so that the first deep trench isolation structure 231 can effectively prevent the crosstalk of optical signals between adjacent photoelectric sensing regions 220. Figure 2 The first deep trench isolation structure 231 shown includes a metal layer 231b. The doping layer adjacent to the metal layer 231b among the multiple doping layers included in the photoelectric sensing region 220 does not contain metal elements, so that electrons between adjacent photoelectric sensing regions 220 do not flow through the metal layer 231b included in the isolation structure 230, so that the isolation structure 230 can well balance preventing optical signal crosstalk and preventing electrical signal crosstalk.

[0057] Figure 2The middle grid 250 includes a high-k dielectric layer 251, a metal layer 252, and a barrier layer 253 stacked sequentially from bottom to top on the isolation structure 230. Specifically, the high-k dielectric layer 251 included in the grid 250 and the high-k dielectric layer 231a included in the first deep trench isolation structure 231 can each be made of tantalum oxide, the metal layer 252 included in the grid 250 and the metal layer 231b included in the first deep trench isolation structure 231 can each be made of aluminum, and the barrier layer 253 included in the grid 250 and the barrier layer 231c included in the first deep trench isolation structure 231 can each be made of titanium nitride (TiN). In addition, the oxide layer 231d included in the first deep trench isolation structure 231 can be made of silicon oxide.

[0058] Figure 2 The multiple doping layers included in the middle photoelectric sensing region 220 are divided into a first doping layer group and a second doping layer group. The first doping layer group and the second doping layer group are stacked, wherein the first doping layer group includes a doping layer 221, a doping layer 222 and a doping layer 223, and the three doping layers are stacked; the second doping layer group includes a doping layer 224 and a doping layer 225, and the two doping layers are alternately arranged along the direction in which the photoelectric sensing region 220 and the isolation structure 230 are alternately arranged. The stacked and alternately arranged doping layers in the photoelectric sensing region 220 can produce a good conductivity gradient, thereby optimizing the migration path of photogenerated carriers, significantly reducing the recombination rate of photogenerated carriers, and increasing the number of photogenerated carriers that generate effective electrical signals, which plays an important role in improving the photoelectric conversion performance of the image sensor. Among the multiple doping layers included in the photoelectric sensing region 220, the doping layer 222 is adjacent to the metal layer 231b in the first deep trench isolation structure 231, and the doping layer 222 is a silicon material doped with arsenic (As). In addition, the doping layer 221, the doping layer 223 and the doping layer 225 are silicon materials doped with phosphorus (P), and the doping layer 224 is silicon material doped with antimony (Sb), wherein the doping layer 221 is adjacent to the high-k dielectric layer 231a in the first deep trench isolation structure 231, the doping layer 223 is adjacent to the barrier layer 231c in the first deep trench isolation structure 231, and the doping layer 224 is adjacent to the oxide layer 231d in the first deep trench isolation structure 231.

[0059] Corresponding to the image sensor provided in the above embodiment, another embodiment of the present application further provides a method for manufacturing an image sensor. Figure 3 The method for manufacturing the image sensor provided by the embodiment of the present application is shown as follows: Figure 3 As shown, the manufacturing method includes:

[0060] Step S110, providing a substrate;

[0061] Step S120, forming a photoelectric sensing region on the substrate and forming an isolation structure between adjacent photoelectric sensing regions on the substrate, wherein the isolation structure is a grid structure with light-blocking function formed by stacking multiple material layers;

[0062] Step S130 , forming a filter element on the photoelectric sensing area and forming a grid on the isolation structure.

[0063] Figure 4a to Figure 4h This is a schematic diagram of an execution process of step S120. Figure 4a to Figure 4h Step S120 will be described in detail.

[0064] Step S120 may include: forming an isolation layer on the substrate, and then etching the isolation layer to form a second deep trench isolation structure included in the isolation structure at a preset position of the isolation structure.

[0065] Specifically, a substrate may be provided first, and then ion implantation may be performed into the substrate to form Figure 4a The isolation layer 211 shown in the figure, the material used for the substrate can be silicon material, and the ions implanted are, for example, gallium (Ga) ions. The formed isolation layer 211 divides the substrate into a substrate 210 and an epitaxial layer 212, and then the epitaxial layer 212 is removed, so as to Figure 4b As shown in FIG. 1 , an isolation layer 211 is formed on the substrate 210. The epitaxial layer 212 can be removed by chemical mechanical polishing (CMP), so that the surface of the isolation layer 211 is flattened while the epitaxial layer 212 is removed. A shallow trench isolation structure 213 is pre-formed in the substrate 210. The etching of the isolation layer 211 is as follows: Figure 4c The second deep trench isolation structure 232 is formed one-to-one with the shallow trench isolation structure 213, and the second deep trench isolation structure 232 can be formed by dry etching. The shallow trench isolation structure 213, the first deep trench isolation structure 231 formed later, and the second deep trench isolation structure 232 are combined to achieve isolation between adjacent photoelectric sensing regions 220.

[0066] Step S120 may also include: forming a first stacked structure on the surface of the substrate, the first stacked structure including multiple material layers stacked together; etching the first stacked structure to form a first groove and a first deep trench isolation structure located at a preset position of the isolation structure separated by the first groove; and forming a photoelectric sensing region including multiple doping layers in the first groove.

[0067] Specifically, the types of the multiple material layers included in the first stacked structure, the thickness of each material layer, and the stacking order of the multiple material layers are determined by the role of the first deep trench isolation structure formed after etching, and the relevant description of the first deep trench isolation structure in the above embodiment can be referred to, and no further description is given here. The projection of the edge of the first deep trench isolation structure formed by etching the first stacked structure on the surface of the second deep trench isolation structure can be controlled to fall within the edge of the surface of the second deep trench isolation structure, so that the photoelectric sensing area formed in the first groove has a larger space for photoelectric conversion as a whole, and the surface of the photoelectric sensing area has a larger area for photosensitivity, thereby ensuring that the photoelectric conversion performance of the image sensor is basically not affected.

[0068] The above-mentioned formation of a photoelectric sensing region including a plurality of doped layers in the first groove may include: forming a plurality of doped layers in the first groove in sequence by deposition or epitaxy (EPI) to form a first doped layer group included in the photoelectric sensing region; further, it may include: forming a target doped layer on the surface of the first doped layer group by deposition or epitaxy in the first groove, the target doped layer including a first region and a second region arranged alternately along the direction in which the photoelectric sensing region and the isolation structure are alternately arranged; diffusing the doped elements in the first region by an annealing process, and implanting a doped element different from that in the second region in the first region by an ion implantation process to form a second doped layer group included in the photoelectric sensing region. The first doped layer group is a stacked structure formed by different doped layers, and the second doped layer group is a mixed structure formed by different doped layers. The formation of the doped layer in the first groove by deposition or epitaxy in the above-mentioned step is to ensure that the plurality of doped layers are closely combined, thereby avoiding leakage current in the photoelectric sensing region during the use of the image sensor. In view of this, chemical vapor deposition (CVD) is often used for this deposition method.

[0069] Figure 4d Shown to form Figure 2 In the exemplary image sensor process shown, a first stacked structure including a high-k dielectric layer 231a, a metal layer 231b, a barrier layer 231c and an oxide layer 231d is formed on a substrate 210 by multiple deposition processes; Figure 4e The first groove 233 formed by etching the first stacked structure and the first deep trench isolation structure 231 separated by the first groove 233 are shown; Figure 4f The doping layer 221, the doping layer 222 and the doping layer 223 are sequentially formed in the first groove 233. Figure 4g The target doping layer 224' is formed on the surface of the first doping layer group in the first groove 233 by epitaxy. The target doping layer 224' includes a first region in the dotted frame and a second region outside the dotted frame. Figure 4hThe doping layer 224 formed in the first region and the doping layer 225 formed in the second region by combining an annealing process with an ion implantation process are shown.

[0070] Figure 4i to Figure 4j This is a schematic diagram of an execution process of step S130. Figure 4i to Figure 4j Step S130 will be described in detail.

[0071] Step S130 may include: forming a second stacked structure on the surface of the photoelectric sensing region and the surface of the isolation structure; etching the second stacked structure to form a second groove and a grid formed by the second groove and located on the surface of the isolation structure; and forming a filter element in the second groove.

[0072] Specifically, the types of the multiple material layers included in the second stacked structure and the stacking order of the multiple material layers are determined by the role of the grid formed after etching, and the relevant description of the grid in the above embodiment can be referred to, which will not be repeated here.

[0073] Figure 4i Shown to form Figure 2 In the exemplary image sensor process shown in FIG. 1 , a second stacked structure including a high-k dielectric layer 251, a metal layer 252 and a barrier layer 253 is formed on the surface of the photoelectric sensing region 220 and the surface of the isolation structure 230. Figure 4j The second groove 254 formed by etching the second stacked structure and the grid 250 separated by the second groove 254 are shown. The grid 250 is a composite metal grid, which can well reduce the generation of dark current. Figure 4j The second groove 254 shown in FIG. Figure 2 The filter element 240 shown in the figure includes a blue filter element 241, a green filter element 242 and a red filter element 243. It should be noted that the filter element 240 includes a color filter and a micro lens located on the surface of the color filter. Since the surface of the micro lens is convex, Figure 2 The blue filter element 241 , the green filter element 242 , and the red filter element 243 are all in a convex shape.

[0074] The embodiments of the present application are described above, and these embodiments do not describe all the details in detail, nor do they limit the application to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. An image sensor, characterized in that: include: substrate; A photoelectric sensing region disposed on the substrate and an isolation structure disposed between adjacent photoelectric sensing regions on the substrate, wherein the isolation structure is a grid structure having a light-blocking function formed by stacking a plurality of material layers; A filter element is arranged on the photoelectric sensing area and a grid is arranged on the isolation structure.

2. The image sensor according to claim 1, characterized in that The isolation structure includes a plurality of material layers, which are a high-k dielectric layer, a metal layer, a barrier layer and an oxide layer from bottom to top on the substrate; The photoelectric sensing region includes a plurality of doping layers, and the doping layer in the photoelectric sensing region adjacent to the metal layer in the isolation structure does not contain metal elements.

3. The image sensor according to claim 2, characterized in that The photoelectric sensing region includes a plurality of doped layers divided into a first doped layer group and a second doped layer group, wherein the first doped layer group and the second doped layer group are stacked; The doped layers in the first doped layer group are stacked, and the doped layers in the second doped layer group are alternately arranged along the direction in which the photoelectric sensing regions and the isolation structures are alternately arranged.

4. The image sensor according to claim 2, characterized in that: The grid includes a high-k dielectric layer, a metal layer and a barrier layer which are sequentially stacked from bottom to top on the isolation structure.

5. A method for manufacturing an image sensor, characterized in that: include: providing a substrate; forming a photoelectric sensing region on the substrate and forming an isolation structure between adjacent photoelectric sensing regions on the substrate, wherein the isolation structure is a grid structure with light-blocking function formed by stacking multiple material layers; A filter element is formed on the photoelectric sensing area and a grid is formed on the isolation structure.

6. The method for manufacturing an image sensor according to claim 5, characterized in that: The isolation structure includes a first deep trench isolation structure, a photoelectric sensing region is formed on the substrate, and an isolation structure is formed between adjacent photoelectric sensing regions on the substrate, including: forming a first stacked structure on the surface of the substrate, wherein the first stacked structure includes a plurality of material layers stacked; Etching the first stacked structure to form a first groove and the first deep trench isolation structure formed by the first groove and located at a preset position of the isolation structure; The photoelectric sensing region including a plurality of doping layers is formed in the first groove.

7. The method for manufacturing an image sensor according to claim 6, characterized in that: The photoelectric sensing region including a plurality of doped layers is formed in the first groove, comprising: forming a plurality of doped layers in the first groove in sequence by deposition or epitaxy to form a first doped layer group included in the photoelectric sensing region.

8. The method for manufacturing an image sensor according to claim 7, characterized in that: The photoelectric sensing region including a plurality of doping layers is formed in the first groove, and further comprising: forming a target doping layer on the surface of the first doping layer group in the first groove by deposition or epitaxy, wherein the target doping layer includes first regions and second regions alternately arranged along a direction in which the photoelectric sensing regions and the isolation structures are alternately arranged; The doping elements in the first region are diffused by an annealing process, and a doping element different from that in the second region is implanted into the first region by an ion implantation process to form a second doping layer group included in the photoelectric sensing region.

9. The method for manufacturing an image sensor according to claim 6, wherein: The isolation structure further includes a second deep trench isolation structure, a photoelectric sensing region is formed on the substrate, and an isolation structure is formed between adjacent photoelectric sensing regions on the substrate, and further includes: forming an isolation layer before forming the first stacked structure on the substrate; The isolation layer is etched to form the second deep trench isolation structure at a preset position of the isolation structure, wherein a projection of an edge of the first deep trench isolation structure on a surface of the second deep trench isolation structure falls within an edge of the surface of the second deep trench isolation structure.

10. The method for manufacturing an image sensor according to claim 5, characterized in that: Forming a filter element on the photoelectric sensing area and forming a grid on the isolation structure, comprising: forming a second stacked structure on the surface of the photoelectric sensing region and the surface of the isolation structure; Etching the second stacked structure to form a second groove and a grid formed by the second groove and located on the surface of the isolation structure; The filter element is formed in the second groove.

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