Method for manufacturing image sensor and image sensor
By forming a filling structure in a photodiode and filling it with a high-k dielectric, the bottleneck in improving pixel performance of image sensors has been solved, resulting in improved optical response and full-well capacitance, reduced pixel white point and dark current, reduced process complexity and cost, and improved infrared response.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GALAXYCORE SHANGHAI
- Filing Date
- 2024-12-04
- Publication Date
- 2026-06-05
AI Technical Summary
Existing image sensors face bottlenecks in improving pixel performance, particularly in balancing manufacturing costs and process difficulty in reducing pixel size, increasing full-well capacitance, reducing pixel white point and dark current, and improving infrared response.
A filling structure extending along a first direction is formed in the photodiode, and a cavity scheme is designed in the filling structure to fill the high-k dielectric to improve the full-well capacitance and optical response, while improving pixel white point and dark current phenomena. The process uses the same manufacturing process for the isolation structure between pixels to reduce complexity and cost.
It significantly improves the optical response and full-well capacitance of the image sensor, reduces pixel white point and dark current, reduces process complexity and manufacturing cost, enhances infrared response capability, and avoids optical crosstalk between pixels.
Smart Images
Figure CN122161192A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of image sensors, and more particularly to a method for manufacturing an image sensor and an image sensor itself. Background Technology
[0002] Image sensors utilize the photoelectric conversion function of photoelectric devices in a pixel array to convert the light image on the photosensitive surface into an electrical signal proportional to the light image. This signal is then processed and stored by peripheral circuits to record image information.
[0003] like Figure 1 The image shown is an example of a conventional pixel in an image sensor, where adjacent photodiodes 001 (corresponding pixels) formed in a semiconductor substrate are separated by an isolation structure 02. However, it is difficult to further improve the pixel performance of image sensors manufactured using conventional techniques. Performance bottlenecks exist in areas such as reducing pixel size, increasing full-well capacitance (FWC), reducing pixel white point and dark current, and improving infrared response, making it difficult to balance the needs of manufacturing cost and process complexity. Summary of the Invention
[0004] Based on the problems described above, this invention proposes a method for manufacturing an image sensor and an image sensor in general. The method involves forming a filling structure extending along a first direction within a photodiode, the filling structure having a portion corresponding to a second type (e.g., N-type) of the photodiode. Building upon this method, to design high-quality front-illuminated / back-illuminated image sensors, this invention designs and forms the filling structure with a cavity to significantly improve optical response and increase full-well capacitance. To design high-quality back-illuminated image sensors, in addition to designing the filling structure with a cavity to improve optical response and full-well capacitance, this invention further provides filling the cavity of the filling structure with an isolation dielectric (high-K dielectric) to further improve full-well capacitance and optical response, while also further improving pixel white point and dark current phenomena. Furthermore, the process for the filling structure shares the same manufacturing process as the isolation structure between pixels, which can greatly reduce process complexity and manufacturing costs. Simultaneously, the material composition of the filling structure can be improved by utilizing the corresponding material in existing processes, further improving issues such as pixel white point, dark current, and optical response. Furthermore, the filling structure formed in the photodiode also helps to improve the infrared response. The filling structure is in one or a combination of shapes such as annular, blocky hole, curved, and straight in the plane perpendicular to the first direction. In particular, the filling structure is formed in a generally annular shape, which helps the photodiode to focus the light in the corresponding photodiode and avoid light crosstalk between pixels.
[0005] In a first aspect, embodiments of the present invention provide a method for manufacturing an image sensor, the method comprising: A first-type semiconductor substrate having a first side and a second side is provided; A filling structure extending along a first direction is formed in some or all of the photodiodes; wherein the formation of the filling structure includes the following steps: Step S1: Form a trench from the first surface of the semiconductor substrate into the semiconductor substrate; Step S2: A region corresponding to the second type of photodiode is formed on the outer wall portion of the trench.
[0006] In one specific embodiment, after step S2, a photodiode is constructed in the semiconductor substrate, and a first circuit layer and a second circuit layer are formed on the first surface.
[0007] In one specific embodiment, the groove is in the shape of one or a combination of multiple shapes, such as annular, blocky hole, curved, or straight, in a plane perpendicular to the first direction.
[0008] In one specific embodiment, the trenches located in different photodiodes may have different or the same dimensions.
[0009] In one specific embodiment, step S2 specifically involves: forming an epitaxial layer that lines the inner wall of the trench through at least one epitaxial process, and closing the opening of the epitaxial layer to form a first cavity.
[0010] In one specific embodiment, after step S2, the formation of the filling structure further includes the following steps for forming a back-illuminated image sensor: Step S3: Thin the second side of the semiconductor substrate to expose the first cavity; Step S4: Fill the first cavity with an isolation dielectric; Alternatively, after step S2, the formation of the filling structure does not include steps S3 and S4 for forming a front-illuminated or back-illuminated image sensor.
[0011] In one specific embodiment, the isolation dielectric completely fills the first cavity, or the isolation dielectric fills the first cavity in a manner that forms a second cavity.
[0012] In one specific embodiment, one or more of the filling structures are formed in a single photodiode.
[0013] In one specific embodiment, the filling structure is formed at the center of the photodiode and / or at a position off-center.
[0014] In one specific embodiment, the isolation dielectric includes one or more combinations of hafnium oxide (HfO), aluminum oxide (AlO), zirconium oxide (ZrO), titanium oxide (TiO), strontium oxide (SrO), barium oxide (BaO), barium titanate (BaTiO3), tantalum oxide (Ta2O3), lanthanum oxide (La2O3), yttrium oxide (Y2O3), and Ta2O5.
[0015] In one specific embodiment, in addition to the isolation dielectric, the first cavity is also filled with one or more combinations of silicon oxide and polycrystalline silicon.
[0016] In one specific embodiment, the method further includes forming an isolation structure for isolating adjacent photodiodes; and the isolation structure is formed by the same or different method as the filling structure.
[0017] In one specific embodiment, the filling structure and the isolation structure are formed by the same method and the same process.
[0018] Secondly, embodiments of the present invention also provide an image sensor, which is formed according to the manufacturing method of the image sensor according to any of the foregoing embodiments.
[0019] Compared with existing technologies, the technical solution of this invention has the following beneficial effects: The image sensor manufacturing method and image sensor proposed in this invention, by forming a filling structure extending along a first direction in a photodiode, wherein the filling structure has a portion corresponding to the second type (e.g., N-type) of the photodiode, can improve the full-well capacitance, which is beneficial for further miniaturization of pixel size. Based on this method, in order to design a high-quality front-illuminated / back-illuminated image sensor, this invention particularly designs the filling structure with a cavity to significantly improve optical response and full-well capacitance, thereby overcoming the disadvantage of front-illuminated / back-illuminated image sensors in optical response; in order to design a high-quality back-illuminated image sensor, in addition to designing the filling structure with a cavity to improve optical response and full-well capacitance, it further provides filling the cavity of the filling structure with an isolation dielectric (high-K dielectric) to further improve full-well capacitance and optical response, while also further improving pixel white point and dark current phenomena. Furthermore, the filling structure shares the same manufacturing process as the isolation structure between pixels, which can greatly reduce process complexity and manufacturing costs. Simultaneously, it can utilize existing materials in the corresponding process to improve the material composition of the filling structure, further improving issues such as pixel white points and dark current without increasing process difficulty or cost. Moreover, this filling structure formed in the photodiode also helps improve infrared response. The filling structure, in a plane perpendicular to the first direction, takes the shape of one or a combination of multiple shapes, including annular, blocky hole, curved, and straight lines. Furthermore, the filling structure is generally annular, which helps the photodiode focus light within the corresponding photodiode, avoiding light crosstalk between pixels. Attached Figure Description
[0020] The accompanying drawings, which form part of this specification, are used to further understand the invention. The drawings illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.
[0021] Figure 1 For the pixel pattern of an existing image sensor.
[0022] Figures 2A-2B These are planar screenshots or longitudinal cross-sectional views taken during the fabrication process of an image sensor according to an embodiment of the present invention.
[0023] Figures 3A-3H This is an embodiment of the pixel pattern of the image sensor of the present invention.
[0024] Figures 4A-4E This is an embodiment of the manufacturing method of the back-illuminated image sensor of the present invention; wherein, Figures 4A-4C Another embodiment of the manufacturing method of the front-illuminated / back-illuminated image sensor applicable to the present invention.
[0025] Figure 4E ´For appendix Figure 4E Another embodiment of the manufacturing steps of the back-illuminated image sensor of the present invention. Detailed Implementation
[0026] The following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, 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 invention pertains.
[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the present invention.
[0028] In a first aspect, embodiments of the present invention provide a method for manufacturing an image sensor, the method comprising: providing a first-type (e.g., P-type) semiconductor substrate having a first surface and a second surface; as... Figure 2B As shown, the semiconductor substrate 01 has a first surface A and a second surface B; a filling structure 02' extending along a first direction (e.g., from the first surface A to the second surface B) is formed in part or all of the photodiode 001, as illustrated in FIG3, where a filling structure 02' is formed in part of the photodiode 001; further, the formation of the filling structure 02' includes the following steps: Step S1: Form a trench from the first surface of the semiconductor substrate into the semiconductor substrate; such as Figure 2A The diagram illustrates that a trench 0011 is formed in a portion of the photodiode 001.
[0029] Step S2: A region corresponding to the second type (e.g., N type) of the photodiode is formed on the outer wall portion of the trench 0011, as shown in the epitaxial layer 003 in FIG3.
[0030] In one specific embodiment, the trench 0011 used to form the filling structure 02' has one or a combination of shapes among annular, blocky hole, curved, and straight shapes in a plane perpendicular to the first direction. The dimensions of the trenches located in different photodiodes can be the same or different. Preferably, the trenches 0011 used to form the filling structure 02' in the same image sensor have two or more different sizes to suit structures such as large and small pixels. In the final image sensor, the depth of the trench 0011 preferably satisfies the requirement that the fabricated filling structure 02' penetrates the first surface A and the second surface B of the semiconductor substrate 01, in order to better balance the needs of performance bottlenecks, manufacturing costs, and process difficulty.
[0031] like Figure 3AAs shown, the groove 0011 used to form the filling structure 02' has a circular hole shape in a plane perpendicular to the first direction; however, it is not limited to a circle, and can also be a square, elongated, rhomboid, hexagonal, octagonal, or other regular or irregular shape. Preferably, as Figure 3B The hole shown is shaped like the number 8. Figure 3C Examples of crescent-shaped hollows, such as Figure 3D The image shown is in the shape of a radial star, as... Figure 3E As shown, it is shaped like a cross. By designing the shape of the void plane, the PN junction area can be increased, which can significantly improve the full-well capacitance.
[0032] Further preferred, such as Figure 3F As shown, groove 0011 is annular in shape in a plane perpendicular to the first direction. The accompanying drawing illustrates a circular shape, but the embodiments of the present invention are not limited to this; any other annular shape is within the scope of the present invention. For example, as shown in the attached drawing… Figure 3G , 3H Examples of annular structures with different inner and outer ring shapes are provided. By designing the planar shape of the trench 0011, filling structures 02' with different quality performance can be obtained to improve the imaging quality of the image sensor. Furthermore, embodiments of the present invention, by setting the trench 0011 to be annular in a plane perpendicular to the first direction, facilitate the formation of a filling structure 02' including a region corresponding to the second type (e.g., N-type) of the photodiode on the outer wall portion of the trench 0011 to improve the full-well capacitance. At the same time, the annular shape of the filling structure 02' also helps to confine the light to the corresponding photodiode region when incident light irradiates the photodiode, thereby avoiding optical crosstalk between adjacent pixels.
[0033] In the previous embodiments, a single photodiode was described as having a filling structure formed in its center; however, the present invention is not limited thereto, and multiple filling structures may also be formed in a single photodiode. For example, the filling structure is preferably formed in the center of the photodiode; however, furthermore, the filling structure is preferably and / or may be located off-center.
[0034] In one specific embodiment, the method of the present invention includes the step of forming an isolation structure 02 for isolating adjacent photodiodes; and the filling structure 02' of the present invention can be formed with the isolation structure 02 using the same or different methods. In a preferred embodiment, the filling structure 02' of the present invention and the isolation structure 02 are formed using the same method and the same process to improve performance bottlenecks while reducing manufacturing costs and process difficulty.
[0035] The following example illustrates the manufacturing method of the image sensor of the present invention.
[0036] First, trenches are formed. Trench 0011 is formed in the P-type semiconductor substrate 01 using various processes such as photolithography / etching. In this embodiment of the invention, the process used to form trench 0011, the depth of trench 0011, the opening size of trench 0011, and the side surface shape of trench 0011 are not specifically limited. The formation of the filling structure 02' may specifically include the following steps: such as... Figure 4A As shown, step S1, which forms a trench 0011 from the first surface A of the semiconductor substrate into the semiconductor substrate 01, can be formed simultaneously with the trench 002 forming the isolation structure 02.
[0037] Second, epitaxial growth. After the trench 0011 is formed, an epitaxial process is performed; during the epitaxial growth process, one or more epitaxial operations can be performed to form an epitaxial layer that backs up the inner wall of the trench, and the opening of the epitaxial layer is closed to form a first cavity. Preferably, the present invention also spontaneously forms the first cavity in the epitaxial layer by adjusting the epitaxial growth process during the formation of the epitaxial layer; the size and formation area of the first cavity are not limited by the present invention; optionally, after epitaxial growth, various processes such as etch-back / CMP / wet etching can be performed to treat the surface of the semiconductor substrate 01. In a preferred embodiment, the epitaxial layer is N-type doped to form the N-type junction region of the photodiode. Figure 4B As shown, an epitaxial layer 003 corresponding to the second type (e.g., N-type) of the photodiode is formed on the outer wall portion of the trench 0011. This step (S2) can also be formed simultaneously with the step of forming the epitaxial layer within the trench 002 of the isolation structure 02, for example... Figure 4B The example shows that the epitaxial layer 003 is formed in both trenches 0011 and 002, and first cavities 0012 and 0021 are formed in trenches 0011 and 002 respectively.
[0038] The epitaxial layer 003 formed by epitaxy is not limited to the doping type; it can be one or more of the following: N-type doped, P-type doped, or undoped epitaxial material. For example, the doping concentration can be between 0 and 1E22.
[0039] Third, image sensor device fabrication. Following this, the image sensor device fabrication process is performed, using FEOL and BEOL processes on the semiconductor substrate 01 to construct the photodiode 001 and peripheral circuitry. For example... Figure 4C As shown, a photodiode 001 is constructed in a semiconductor substrate 01, and a first circuit layer 004 and a second circuit layer 005 are formed on the first surface A. Preferably, after the image sensor device is formed, the fabrication of the front-illuminated / back-illuminated image sensor can be completed by continuing the usual steps of the front-illuminated or back-illuminated image sensor; more preferably, the following fourth and fifth process steps are designed to improve the optical response and full-well capacitance of the pixels of the back-illuminated image sensor.
[0040] Fourth, thinning of the semiconductor substrate. After the BEOL process is completed, a bonding process is performed to thin the semiconductor substrate; for example, thinning can be achieved through CMP. Preferably, as a preferred example of the formation of the filling structure after step S2, it includes step S3: as... Figure 4D As shown, the second surface B of the semiconductor substrate 01 is thinned to expose the first cavity 0021. In the illustrated example, the filling structure and the isolation structure 02 are formed simultaneously, at which point both the first cavity 0012 and the first cavity 0021 can be exposed.
[0041] Fifth, filling the isolation dielectric. Filling the first cavity with an isolation dielectric is step S4 after step S3. For example, an oxidation (DPO) process can be performed to form an oxide layer (not shown) on the surface of the epitaxial layer 003; subsequently, the isolation dielectric is filled, preferably with a high-K dielectric. The type / thickness of the high-K dielectric is not limited in this invention; in one example embodiment, AlO and Ta2O5 layers can be deposited sequentially; in other embodiments, other dielectric layers can be further filled; after the high-K dielectric is filled, the first cavity is preferably completely filled through process adjustments, such as... Figure 4E As shown, an isolation dielectric layer 006 is formed. Preferably, the first cavity can also retain a portion of its area through process adjustments, forming a second cavity to fill the first cavity, as shown below. Figure 4E As shown, the isolation dielectric layer 006 has second cavities 0013 and 0022 corresponding to trenches 0011 and 002. Exemplarily, the isolation dielectric includes one or more combinations of hafnium oxide (HfO), aluminum oxide (AlO), zirconium oxide (ZrO), titanium oxide (TiO), strontium oxide (SrO), barium oxide (BaO), barium titanate (BaTiO3), tantalum oxide (Ta2O3), lanthanum oxide (La2O3), yttrium oxide (Y2O3), and Ta2O5. In other embodiments, in addition to the isolation dielectric, the first cavity is also filled with one or more combinations of silicon oxide and polycrystalline silicon.
[0042] Sixth, the usual steps of image sensor fabrication are followed to complete the image sensor fabrication. Preferably, the steps "fourth, thinning of the semiconductor substrate" and "fifth, filling the isolation dielectric" can be omitted; after the aforementioned "third, device formation of the image sensor," the usual steps of image sensor fabrication are followed to complete the fabrication of the front-illuminated / back-illuminated image sensor. The front-illuminated / back-illuminated image sensor with the cavity-filled structure designed in this invention has advantages in terms of significantly improved optical response and full-well capacitance without affecting other performance aspects, thereby greatly improving the performance of the front-illuminated / back-illuminated image sensor. In other alternative embodiments, the filling structure of the front-illuminated / back-illuminated image sensor can also be filled with material and does not contain a cavity.
[0043] Preferably, after the aforementioned "third, image sensor device formation," the process continues with "fourth, semiconductor substrate thinning" and "fifth, filling with isolation dielectric," followed by the usual steps for image sensor fabrication to complete the back-illuminated image sensor. The back-illuminated image sensor with the filling structure of the isolation dielectric (high-K dielectric) designed in this invention has further advantages in terms of significantly improved full-well capacitance and optical response, without affecting other performance aspects, thereby greatly improving the dynamic range of the back-illuminated image sensor and enhancing imaging performance. In other optional embodiments, the filling structure of the back-illuminated image sensor may not be filled with an isolation dielectric (high-K dielectric) to retain a cavity, or the isolation dielectric may not be filled completely, forming another cavity within the isolation dielectric.
[0044] Furthermore, the preceding embodiments described the case of a first-type (e.g., P-type) semiconductor substrate. Preferably, a second-type (e.g., N-type) epitaxial layer is formed. After the first cavity is formed, an isolation dielectric is filled. The filling of the isolation dielectric can be formed by self-alignment, which is beneficial to improving the uniformity of the pixels. The N-type deep implantation of the photodiode can be formed by doping the N-type epitaxial layer, thereby reducing the N-type deep implantation. At the same time, the process of the embodiments of the present invention can avoid the BDTI (backside deep trench isolation) etching process, which can simplify the process flow and optimize pixel white point and dark current phenomena.
[0045] Secondly, embodiments of the present invention also provide an image sensor, which is formed according to the manufacturing method of the image sensor according to any of the foregoing embodiments.
[0046] Furthermore, the image sensor and its manufacturing method involved in this invention can, in particular, improve the capacitance of the PN junction of the photodiode by controlling the concentration and thickness of the epitaxial layer 003. Simultaneously, the formation of a cavity-filled structure allows for sufficient light transmission within the photodiode region, significantly improving its optical response and thus mitigating the disadvantages of front-illuminated / back-illuminated image sensors in terms of optical response and full-well capacitance. Furthermore, for front-illuminated / back-illuminated image sensors, the introduction of an isolation dielectric 006 (especially an HK dielectric layer) into the cavity of the filling structure can effectively reduce the depletion potential of the N-type region of the photodiode, significantly increasing the full-well capacitance (FWC), thereby providing further possibilities for improving the dynamic range and reducing the size of the image sensor. Moreover, the epitaxial layer 003 formation process employed in this invention can reduce or avoid the defects associated with deep ion implantation of the photodiode. Furthermore, the introduction of the isolation dielectric 006 (especially the HK dielectric layer) can effectively reduce pixel white points and dark current. At the same time, it should be noted that the formation of the filling structure 02', especially the introduction of the isolation dielectric 006 (especially the HK dielectric layer) within it, can further increase the optical path of infrared light in the photodiode, thereby effectively improving the infrared response of the pixel and significantly enhancing the imaging quality of the image sensor.
[0047] In summary, compared with the prior art, the technical solution of the present invention has the following beneficial effects: The image sensor manufacturing method and image sensor proposed in this invention form a filling structure extending along a first direction in a photodiode, the filling structure having a portion corresponding to the second type (e.g., N-type) of the photodiode. Based on this method, for designing high-quality front-illuminated / back-illuminated image sensors, the present invention particularly designs the filling structure with a cavity to significantly improve optical response and full-well capacitance, overcoming the disadvantage of front-illuminated / back-illuminated image sensors in optical response; for designing high-quality back-illuminated image sensors, in addition to designing the filling structure with a cavity to improve optical response and full-well capacitance, the present invention further provides filling the cavity of the filling structure with an isolation dielectric (high-K dielectric) to further improve full-well capacitance and optical response, while also further improving pixel white point and dark current phenomena. Furthermore, the filling structure is formed in a generally ring shape, which is beneficial for the photodiode to focus light into the corresponding photodiode, avoiding optical crosstalk between pixels. Furthermore, the filling structure shares the same manufacturing process as the isolation structure between pixels, which can greatly reduce process complexity and manufacturing costs. Simultaneously, it can utilize existing materials in the corresponding processes to improve the material composition of the filling structure, further improving issues such as pixel white points and dark current without increasing process difficulty or cost. Moreover, this filling structure formed in the photodiode also helps to improve infrared response.
[0048] The basic concepts have been described above. It is clear that the detailed disclosure above is merely illustrative and does not constitute a limitation of the present invention. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to the present invention by those skilled in the art. Such modifications, improvements, and corrections are suggested in this invention and therefore remain within the spirit and scope of the exemplary embodiments of the present invention.
[0049] It should be understood that the embodiments described in this invention are merely illustrative of the principles of the invention. Other modifications may also fall within the scope of this invention. Therefore, alternative configurations of the embodiments of this invention are considered as examples and not limitations, and are regarded as consistent with the teachings of this invention. Accordingly, the embodiments of this invention are not limited to those explicitly described and illustrated herein.
Claims
1. A method for manufacturing an image sensor, the method comprising: A first-type semiconductor substrate having a first side and a second side is provided; A filling structure extending along a first direction is formed in some or all of the photodiodes; wherein the formation of the filling structure includes the following steps: Step S1: Form a trench from the first surface of the semiconductor substrate into the semiconductor substrate; Step S2: A region corresponding to the second type of photodiode is formed on the outer wall portion of the trench.
2. The method according to claim 1, characterized in that, The groove is in the shape of one or a combination of multiple shapes, such as annular, blocky hole, curved, or straight, in a plane perpendicular to the first direction.
3. The method according to claim 2, characterized in that, The trenches located in different photodiodes may have the same or different dimensions.
4. The method according to claim 1, characterized in that, Step S2 specifically involves forming an epitaxial layer that lines the inner wall of the trench through at least one epitaxial process, and closing the opening of the epitaxial layer to form a first cavity.
5. The method according to claim 4, characterized in that, After step S2, a photodiode is constructed in the semiconductor substrate, and a first circuit layer and a second circuit layer are formed on the first surface.
6. The method according to claim 4, characterized in that, Following step S2, the formation of the filling structure further includes the following steps for forming a back-illuminated image sensor: Step S3: Thin the second side of the semiconductor substrate to expose the first cavity; Step S4: Fill the first cavity with an isolation dielectric; Alternatively, after step S2, the formation of the filling structure does not include steps S3 and S4 for forming a front-illuminated or back-illuminated image sensor.
7. The method according to claim 6, characterized in that, The isolation dielectric completely fills the first cavity, or the isolation dielectric fills the first cavity in a manner that forms a second cavity.
8. The method according to claim 1, characterized in that, One or more of the filling structures are formed in a single photodiode.
9. The method according to claim 8, characterized in that, The filling structure is formed at the center of the photodiode and / or at a position off-center.
10. The method according to claim 6, characterized in that, The isolation dielectric includes one or more of the following: hafnium oxide (HfO), aluminum oxide (AlO), zirconium oxide (ZrO), titanium oxide (TiO), strontium oxide (SrO), barium oxide (BaO), barium titanate (BaTiO3), tantalum oxide (Ta2O3), lanthanum oxide (La2O3), yttrium oxide (Y2O3), and Ta2O5.
11. The method according to claim 6, characterized in that, In addition to the isolation dielectric, the first cavity is also filled with one or more combinations of silicon oxide and polycrystalline silicon.
12. The method according to claim 1 or 4, characterized in that, The method further includes forming an isolation structure for isolating adjacent photodiodes; and the isolation structure is formed by the same or different method as the filling structure.
13. The method according to claim 12, characterized in that, The filling structure and the isolation structure are formed by the same method and the same process.
14. An image sensor, characterized in that, The image sensor is formed according to the manufacturing method of the image sensor according to any one of claims 1 to 13.