CN117790523B - Image sensor and manufacturing method thereof - Google Patents
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Abstract
The invention discloses an image sensor and a manufacturing method thereof, and belongs to the field of semiconductor manufacturing. Aiming at the problems of high dark current and crosstalk effect of a back-illuminated image sensor in the prior art, the invention provides an image sensor and a manufacturing method thereof, wherein the image sensor comprises a substrate; an isolation layer arranged on one side of the substrate; a shallow trench isolation structure extending inward from the other surface of the substrate and contacting the isolation layer; the deep trench isolation structure is positioned at one side of the isolation layer away from the shallow trench isolation structure; a grid structure disposed on the deep trench isolation structure; and the multilayer photoelectric sensing area is arranged in the area between the deep trench isolation structures and further comprises a filtering structure between the grid structures. By first removing a portion of the substrate region; forming a multi-layer photoelectric sensing region in the removing region; forming a deep trench isolation structure and a grid structure, and finally setting a filtering structure; it has the effects of reducing crosstalk effect, reducing dark current, and improving image quality.
Description
Technical Field
The present invention relates to the field of semiconductor manufacturing, and more particularly, to an image sensor and a method of manufacturing the same.
Background
The image sensor is a device for converting an optical signal into an electrical signal, and is widely used in fields such as photography and security systems, smart phones, facsimile machines, scanners, and medical electronics. With the continuous development of integrated circuits, the requirements on the pixel performance of the image sensor are increasing. The prior art provides a backside illuminated image sensor (Backside Illumination, BSI) with higher sensitivity, employing better wiring layout, and allowing high-speed recording, applied in the field with high pixel performance requirements for the image sensor. However, in the conventional BSI process, a high-energy ion implantation is used in the front-end process to form a Photodiode (PD), which causes damage and causes a so-called cross talk (cross talk) effect, high dark current, and blurred images.
Disclosure of Invention
Aiming at the problems of high dark current and crosstalk effect of the back-illuminated image sensor in the prior art, the invention provides an image sensor and a manufacturing method thereof, which have the effects of reducing the crosstalk effect, reducing the dark current and improving the image quality.
The aim of the invention is achieved by the following technical scheme: an image sensor, comprising:
a substrate;
An isolation layer arranged on one side of the substrate;
The shallow trench isolation structure extends inwards from the surface of the other side of the substrate to be in contact with the isolation layer;
The deep trench isolation structure is positioned at one side of the isolation layer away from the shallow trench isolation structure;
A grid structure disposed on the deep trench isolation structure; and
The multilayer photoelectric sensing area is arranged in the area between the deep trench isolation structures;
The multilayer photoelectric sensing area is also covered with a first oxide layer and a stabilizing layer which are sequentially arranged.
As an embodiment of the present invention, the multilayer photo-sensing region includes a silicon boride layer, a silicon arsenide layer, and a silicon antimonide layer sequentially disposed from the isolation layer.
As an embodiment of the present invention, the first oxide layer is a silicon dioxide layer.
As an embodiment of the present invention, the stabilizer layer is a titanium nitride layer.
As an implementation mode of the scheme, the deep trench isolation structure consists of an isolation medium layer, and the deep trench isolation structure is arranged corresponding to the shallow trench isolation structure.
As an embodiment of the present invention, the grating structure includes a first grating material layer, a second grating material layer, and a third grating material layer disposed on the isolation medium layer.
As an implementation mode of the scheme, the image sensor further comprises a light filtering structure, the light filtering structure is arranged on the multilayer photoelectric sensing area, and the top of the light filtering structure is in an outwards protruding arc shape.
The invention also provides a corresponding manufacturing method of the image sensor, which comprises the following steps:
providing a substrate;
forming a shallow trench isolation structure in the substrate, wherein the shallow trench isolation structure extends inwards from one surface of the substrate;
forming an isolation layer within the substrate; the isolation layer is contacted with one side of the shallow trench isolation structure;
removing a substrate region facing away from the shallow trench isolation structure by etching;
Depositing and forming a multi-layer photoelectric sensing region on one side of the isolation layer away from the shallow trench isolation structure;
Etching the multi-layer photoelectric sensing region to form a deep trench isolation region;
depositing an isolation medium layer in the deep trench isolation region;
Forming a grid structure layer on the multilayer photoelectric sensing region;
And removing the grid structure layer between the deep trench isolation structures to form a grid structure.
As an embodiment of the present invention, the multilayer photoelectric sensing region is formed by depositing a silicon boride layer, a silicon arsenide layer, and a silicon antimonide layer sequentially disposed from one side of the isolation layer.
As an implementation mode of the scheme, the multilayer photoelectric sensing region is further covered with a first oxide layer and a stabilizing layer which are sequentially deposited, and the first oxide layer and the stabilizing layer cover the bottom of the deep trench isolation region.
As an embodiment of the present invention, the grating structure layer is formed by depositing a first grating material layer, a second grating material layer, and a third grating material layer on the isolation medium layer.
As an embodiment of the present solution, the method further comprises forming a filtering structure between adjacent grid structures.
The scheme provides the corresponding image sensor and the manufacturing method thereof.
Compared with the prior art, the multi-layer photoelectric sensing structure has the unexpected effects that the crosstalk effect is avoided, the problem of non-ideal image imaging caused by the crosstalk effect is completely restrained, the generation of dark current is reduced, the yield of the image sensor is improved, the deep trench isolation structure of the multi-layer structure is increased, the end effect of the substrate can be restrained by the multi-layer structure, the crosstalk problem can be reduced, the dark current is reduced, the process is simple, the front-stage process cannot be influenced, new defects are avoided being introduced, and the imaging effect of the whole device is good.
Drawings
FIG. 1 is a schematic illustration of an embodiment of forming an isolation layer in a substrate;
FIG. 2 is a schematic diagram of removing a substrate on one side of an isolation layer according to an embodiment;
FIG. 3 is a schematic view of an embodiment in which three layers of photoelectric structures are disposed on one side of the isolation layer;
FIG. 4 is a schematic diagram of defining deep trench isolation regions according to one embodiment;
FIG. 5 is a schematic diagram of an embodiment of an oxide layer, a stabilizer layer, a dielectric spacer layer, and a grid material layer;
FIG. 6 is a schematic diagram of an embodiment of a grating structure;
fig. 7 is a schematic diagram illustrating an embodiment of a filter structure.
The reference numerals in the figures illustrate:
10. A substrate; 12. an isolation layer; 13. an etch stop layer; 14. a dielectric layer; 15. a silicon boride layer; 16. a silicon arsenide layer; 17. a silicon antimonide layer;
20. Shallow trench isolation structures; 30. a deep trench region;
41. A first oxide layer; 42. a stabilization layer; 43. an isolation dielectric layer; 44. a first layer of grill material; 45. a second layer of grill material; 46. a third layer of grill material;
50. and a light filtering structure.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention; moreover, the embodiments are not independent, and can be combined with each other as required, so that a better effect is achieved. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that the illustrations provided in the present embodiment merely schematically illustrate the basic idea of the present invention, and only the components related to the present invention are shown in the drawings, not according to the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be changed, and the layout of the components may be more complex.
In the present application, it should be noted that, as terms such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "center", and the like are used, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, only for convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated apparatus or element must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, as used herein, are used for descriptive and distinguishing purposes only and are not to be construed as indicating or implying a relative importance.
Noun interpretation:
Backside illuminated image sensor (Backside Illumination, BSI), BSI (backside illuminated CIS): after the silicon wafer is thinned, a CF and a Micro Lens are built on the back of the photodiode, light is injected from the back, the photosensitive area of the photoelectric element is increased, the loss of the light when the light passes through wiring is reduced, and the photosensitive capacity of the CIS in a weak light environment can be greatly improved; BSI technology has increased the sensitivity of CMOS imaging to a new level. The lenses are arranged on the silicon substrate behind the sensor instead of in front, the front wiring would limit the absorption of light. The sensitivity and light absorption amount under this technique are improved by 40% as compared with the old technique, and finer pixels can be formed. BSI process is complex and difficult, and the yield of early BSI development is a great obstacle. But as semiconductor processes develop, BSI processes are also becoming more mature. The yield rate rises faster. Since the BSI chip is in the form of a backside up, light will directly strike the silicon bulk material near the photodiode, which can be prone to cross-talk due to diffusion to adjacent pixels or recombination with incident light at the backside interface.
Cross talk (Cross talk): the SPAD array adopting the CMOS process has shared electrodes, which helps to improve the integration level. However, after the free electrons of one pixel are accelerated, the free electrons possibly permeate into adjacent pixels, and further trigger counting of the adjacent pixels, so that the image is blurred. BSI also has a corresponding crosstalk effect due to the CMOS process.
Dark current: the current observed in the absence of illumination of the target object is a non-ideal factor and the dark current is integrated into a dark charge and stored at the charge storage node within the pixel. The amount of dark charge is proportional to the integration time, is limited to full well capacity (full WELL CAPACITY), the presence of dark charge reduces the usable dynamic range (DYNAMIC RANGE, DR) of the imager, and it also changes the output voltage of the "dark" (no illumination) environment, resulting in an output other than 0, and therefore dark current levels should be considered as much as possible when restoring an image.
The invention will now be described in detail with reference to the drawings and the accompanying specific examples.
In the conventional back-illuminated image sensor manufacturing process, a high-energy ion implantation is used to form a Photodiode (PD) in the front-end process, which is easy to cause damage to the sensor, and causes a so-called crosstalk effect, and a high dark current, which causes blurring of the image sensor.
In view of the above problems, as shown in fig. 1-7, the present embodiment provides a new backside illuminated image sensor and a method for manufacturing the same.
The backside illuminated image sensor comprises a substrate 10, an isolation layer 12 is arranged on one side of the substrate 10, and a shallow trench isolation structure 20 extends inwards from the other side of the substrate 10 and is in contact with the isolation layer 12; the semiconductor device further comprises a deep trench isolation structure, the deep trench isolation structure is composed of an isolation medium layer 43, the deep trench isolation structure is located on one side, away from the shallow trench isolation structure 20, of the isolation layer 12, the deep trench isolation structure and the shallow trench isolation structure 20 are correspondingly arranged, a multi-layer photoelectric sensing area is arranged between the deep trench isolation structures, the multi-layer photoelectric sensing area shown in the embodiment comprises three layers, a silicon boride layer 15, a silicon arsenide layer 16 and a silicon antimonide layer 17 are sequentially arranged on one side of the isolation layer 12, and the multi-layer photoelectric sensing area is further covered with a first oxide layer 41 and a stabilizing layer 42; the first oxide layer 41 covers the multilayer photo-sensing region, and the stabilization layer 42 is disposed on the first oxide layer 41.
The deep trench isolation structure is further provided with a grating structure, the grating structure comprises a first grating material layer 44, a second grating material layer 45 and a third grating material layer 46 which are arranged on the isolation medium layer 43, a plurality of filtering structures 50 are arranged between the grating structures, and one filtering structure 50 is arranged between every two adjacent grating structures in the embodiment. The embodiment provides an image sensor, which forms a multi-layer photoelectric sensing structure, avoids the crosstalk effect, completely inhibits the problem of non-ideal image imaging caused by the crosstalk effect, reduces the generation of dark current, improves the yield of the image sensor, and does not influence the front-end processing in the technical process.
As shown in fig. 1, in the process of manufacturing the image sensor, a substrate 10, an etching stop layer 13 and a dielectric layer 14 are provided in sequence, where the substrate 10 may be any suitable semiconductor material, such as a silicon wafer, a ceramic wafer, a sapphire, a silicon carbide, a gallium nitride, an aluminum nitride, an indium nitride or a silicon germanium, or may be a laminated structure formed by any combination of materials conforming to the layers, such as the above material substrates, and specifically, the substrate 10 may be selected according to requirements. In the actual manufacturing process, the etching stop layer 13 may be multiple layers, for example, may be two layers, so that cracks of the etching stop layer can be prevented, failure of a metal connection structure can be avoided, other process problems can be avoided, and specific materials of the etching stop layer 13 may be silicon oxide, silicon carbonitride or silicon nitride and the like and are formed by chemical vapor deposition or physical vapor deposition and the like. After the etching stop layer 13 is formed, metal is deposited to form a part of the connection structure, and on the basis of the part of the connection structure, a dielectric layer 14 is formed, wherein the dielectric layer 14 is a silicon oxide layer or other low dielectric material layer, and is formed by methods such as chemical vapor deposition, physical vapor deposition and the like, so that the reliability of the formed metal connection structure is improved. After the dielectric layer 14 is formed, a metal layer is formed on the dielectric layer 14, and the metal layer and a part of the connection structure form a metal connection structure as a metal connection part of the device, and of course, the formation modes of the etching stop layer 13, the dielectric layer 14 and the metal connection structure can be varied. In the front end of line (front end of line, FEOL), corresponding shallow trench isolation structures 20 are formed on the substrate 10, and extend to the inner side of the substrate from the side of the substrate 10 close to the etching stop layer 13, and the specific shallow trench isolation structures 20 may be formed by any manner in the prior art, such as wet etching, dry etching or ion implantation, which will not be described herein.
The existing process method is that after the shallow trench isolation structure 20 is manufactured, the deep trench isolation structure is directly etched on the substrate 10, and then the photoelectric sensing region is formed by high-energy ion implantation, but this method causes damage to the device and causes a so-called crosstalk effect, the dark current is high, and the image blurring is caused, and the single-layer photoelectric sensing structure generally formed by implanting ions into the substrate is an important factor causing the crosstalk effect and the dark current is high. As an innovation point of the scheme, the scheme designs a multilayer photoelectric sensing structure, improves a corresponding manufacturing method and avoids the problems; specifically, after the shallow trench isolation structure 20 is formed, the isolation layer 12 is disposed in the substrate 10, and the isolation layer 12 is disposed at the other end of the shallow trench isolation structure 20, where the shallow trench isolation structure 20 is located in a range from one side of the substrate 10 to the isolation layer 12. The implantation may be performed using an ionized metal plasma (IMP, ionized METAL PLASMA), which may be referred to herein simply as ion implantation, which may be boron ions. IMP is a technique for sputter deposition of a metal target using plasma, and by further exciting sputtered metal ions to form a high density plasma, the deposition process is more efficient and uniform, and a high quality isolation layer 12 can be formed.
After forming the isolation layer 12, the substrate 10 on the other side of the isolation layer 12, i.e. the substrate region not containing the shallow trench isolation structure 20, is removed, as shown in fig. 2. The removal may be performed in several ways, for example, a planarization process such as chemical mechanical polishing may be used, so long as the corresponding region is removed, so that the other side of the isolation layer 12 is temporarily completely exposed.
As shown in fig. 3, after removing the redundant substrate area, a silicon boride layer 15, a silicon arsenide layer 16 and a silicon antimonide layer 17 are sequentially disposed on the exposed side of the isolation layer 12, the finally formed three-layer structure is a photoelectric sensing area, the silicon boride layer 15 is closest to the isolation layer 12, the silicon antimonide layer 17 is farthest from the isolation layer 12, the silicon arsenide layer 16 is disposed between the silicon boride layer 15 and the silicon antimonide layer 17, the three-layer photoelectric structure can be disposed by chemical vapor deposition (CVD, chemical Vapor Deposition) or other suitable methods, and Sb, as and P are respectively injected by CVD to form such a three-layer structure. Because the three-layer structure can finally form a multi-layer photoelectric sensing structure, the method is technically not a mode of directly forming a photoelectric sensing region by high-energy ion implantation, the method can avoid the crosstalk effect, and the problem of non-ideal image imaging caused by the crosstalk effect is completely restrained. The function of the photoelectric induction of the finally manufactured image sensor is performed by the photoelectric induction structure of the three-layer structure.
As shown in fig. 4, after the formation of the photo-sensing region, a deep trench region 30 is defined, the deep trench region 30 extends from the surface of the silicon antimonide layer 17 to contact with the isolation layer 12, and the deep trench region 30 is disposed corresponding to the shallow trench isolation structure 20, i.e. the center lines of the deep trench region 30 and the shallow trench isolation structure 20 in the depth direction are located on the same line. The specifically defined method may be performed by photolithography and dry etching, the position of the deep trench may be defined by using the patterned photoresist layer as a mask, or by using a mask plate, and then the deep trench region 30 may be formed by using an etching method, and may be performed by using dry etching, wet etching, or an etching method combining dry etching and wet etching, etc., where the dry etching is performed by using a plasma etching method, the region to be removed may be easily quantitatively removed, so as to ensure accurate formation of the deep trench region 30.
As shown in fig. 5, after the definition of the deep trench region 30 is completed, a first oxide layer 41, a stabilizing layer 42, an isolation dielectric layer 43, a first grid material layer 44, a second grid material layer 45 and a third grid material layer 46 are sequentially deposited, wherein the first oxide layer 41 forms a thin layer along the surface of the deep trench region 30 and the surface where the photoelectric sensing region is located, and can be enhanced by using plasma on the basis of the thin layer by using a chemical vapor deposition mode, the first oxide layer 41 can be composed of SiO 2, the first oxide layer 41 can be used as a substrate on the surface, and the end effect of the substrate can be suppressed, so that the crosstalk problem is reduced.
After the first oxide layer 41 is fabricated, a process of the stabilizing layer 42 is performed, and as a mode of this embodiment, the stabilizing layer 42 is a TiN layer, the Ti target material may be bombarded by Ar ions through physical vapor deposition (Physical Vapor Deposition, PVD) mode, ti reacts with N2 to generate TiN, and TiN is deposited, where the TiN layer can prevent interdiffusion between Al and silicon dioxide, and T has an effect of improving electromigration. A TiN layer is covered over the first oxide layer 41 to form a thin layer. The thickness of each layer can be adjusted according to the needs, and is not limited. The first oxide layer 41 and the stabilizing layer are fabricated in combination with the multi-layer photo-sensing region, which comprehensively avoids diffusion of the image sensor to adjacent pixels or diffusion at the back interface from recombining with incident light, and avoids crosstalk effects by suppressing and stabilizing light through the three-layer photo-sensing region and the corresponding end effect.
After the first oxide layer 41 and the stabilizing layer 42 are completed, which means that the deep trench region 30 is paved with a bottom layer, then an isolation medium is deposited on the stabilizing layer 42, the isolation medium can be Hot-Al, a deposition device is adopted to deposit Hot aluminum, the whole deep trench region 30 is filled, and an isolation medium layer 43 with a certain thickness is formed on the whole stabilizing layer 42, so that the setting of the isolation medium layer 43 is completed; then, the first grating material layer 44, the second grating material layer 45 and the third grating material layer 46 are disposed, the first grating material layer 44 is disposed on the isolation medium layer 43, the second grating material layer 45 is disposed on the first grating material layer 44, the third grating material layer 46 is disposed on the second grating material layer 45, in a specific embodiment, the first grating material layer 44 may be an alumina layer (Al 2O3), the second grating material layer 45 is a tungsten layer (W), the third grating material layer 46 is a silica layer (SiO 2), and the three-layer grating material layer may be disposed by deposition, such as chemical deposition or physical deposition, so that a complete multi-layer isolation is formed around the photo-sensing region by disposing multiple oxide layers, thereby preventing crosstalk between adjacent photo-sensing regions and improving the imaging quality of the image sensor. The thickness of each layer can be adjusted according to the needs, and is not limited.
As shown in fig. 6, after three grating material layers are formed, the positions of the grating structure are defined, the grating structure is disposed in the vertical direction of the deep trench region 30, specifically, the positions of the grating structure can be defined by using the patterned photoresist layer as a mask, or by using a mask plate, then the grating structure is formed by using an etching method, specifically, the etching method such as dry etching, wet etching or a combination of dry etching and wet etching is used, and the dry etching is adopted in this embodiment. The filter structure 50 is subsequently disposed between the grating structures, and the three grating materials between the grating structures and the isolation medium layer 43 are removed after etching, so that the stabilizing layer 42 is exposed. At this time, the bottom layer of the deep trench isolation structure is the isolation dielectric layer 43, and the isolation dielectric layer 43 is equivalent to a portion protruding from the surface of the stabilizing layer 42, so that the isolation effect is more excellent.
As shown in fig. 7, after the grating structure is completed, a Filter structure 50 (Color Filter) is disposed between adjacent grating structures, and the Filter structure 50 is located on the photo sensing region. The filter structure 50 includes, for example, a plurality of color filters, and the plurality of color filters form a color filter array. Each color filter corresponds to one photoelectric sensing area. In this embodiment, the filtering structure may include color filters of at least three primary colors, and may be arranged in any suitable combination. A transparent filter sheet, a blue filter sheet, a green filter sheet, a red filter sheet and a transparent filter sheet can be arranged in a staggered manner. The color filter may be a polymeric material such as a negative photoresist based on an acrylic polymer, and may contain a color dye. After the light passes through the color filter, the color can be changed, the high transmittance of a certain wave band is maintained, and the photoelectric conversion effect is further enhanced. In an embodiment of the invention, the top of the optical filtering structure is in an outwards convex arc shape, so that incident light can be focused on the photoelectric sensing area, the curvature of the surface of the optical filtering structure can be changed according to the light focusing requirement, and the light sensing efficiency is improved. After the formation of the filter structure 50, the formation of the microlens structure on the filter structure may be continued, and the microlens structure may be formed in any manner selected to form the microlens structure, which is not particularly limited in the present invention. The number of the photo-sensing regions and the number of the filtering structures can be set according to practical requirements, which is only an example in the present embodiment.
In summary, the present invention provides an image sensor and a method for manufacturing the same, which unexpectedly has the effects that the multilayer structure formed by the multilayer photoelectric sensing structure and the stable layer oxide layer arranged on the deep trench isolation structure avoids the crosstalk effect, avoids the ion implantation with high energy from the process, prevents the damage of devices, completely suppresses the problem of non-ideal image imaging caused by the crosstalk effect, reduces the generation of dark current, improves the yield of the image sensor, does not affect the front-end process in the process, increases the deep trench isolation structure of the multilayer structure, and the multilayer structure not only can suppress the end effect of the substrate, but also can reduce the crosstalk problem, reduce the dark current, and has simple process. The image sensor with high quality is obtained by the method. The top of the light filtering structure is arranged in an arc shape with the protruding outside, the curvature of the surface of the light filtering structure can be selected, incident light is focused on the photoelectric sensing area, and the light sensing efficiency is improved.
The foregoing has been described schematically the invention and embodiments thereof, which are not limiting, but are capable of other specific forms of implementing the invention without departing from its spirit or essential characteristics. The drawings are also intended to depict only one embodiment of the invention, and therefore the actual construction is not intended to limit the claims, any reference number in the claims not being intended to limit the claims. Therefore, if one of ordinary skill in the art is informed by this disclosure, a structural manner and an embodiment similar to the technical scheme are not creatively designed without departing from the gist of the present invention. In addition, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" preceding an element does not exclude the inclusion of a plurality of such elements. The various elements recited in the product claims may also be embodied in software or hardware. The terms first, second, etc. are used to denote a name, but not any particular order.
Claims (7)
1. An image sensor, comprising:
a substrate;
An isolation layer arranged on one side of the substrate;
a shallow trench isolation structure extending inward from the other surface of the substrate and contacting the isolation layer;
the deep groove isolation structure is positioned at one side of the isolation layer, which is away from the shallow groove isolation structure, and the deep groove isolation structure consists of an isolation medium layer;
A grid structure disposed on the deep trench isolation structure; and
The multilayer photoelectric sensing area is arranged in the area between the deep trench isolation structures;
the multilayer photoelectric sensing region is also covered with a first oxide layer and a stabilizing layer which are sequentially arranged, and the first oxide layer and the stabilizing layer cover the top surface and the side wall of the multilayer photoelectric sensing region and extend to the position below the bottom surface of the deep trench isolation structure;
The first oxide layer is a silicon oxide layer, the stabilizing layer is a titanium nitride layer, and the isolating medium layer is an aluminum layer.
2. The image sensor of claim 1, wherein the multi-layered photo-sensing region comprises a silicon boride layer, a silicon arsenide layer, and a silicon antimonide layer sequentially disposed from one side of the isolation layer.
3. The image sensor of claim 1, wherein the deep trench isolation structures are disposed corresponding to the shallow trench isolation structures.
4. The image sensor of claim 1 wherein the grating structure comprises a first layer of grating material, a second layer of grating material, and a third layer of grating material disposed on the isolation dielectric layer.
5. A method for manufacturing an image sensor comprises the following steps:
providing a substrate;
forming a shallow trench isolation structure in the substrate, wherein the shallow trench isolation structure extends inwards from one surface of the substrate;
Forming an isolation layer in the substrate by ion implantation; the isolation layer is contacted with one side of the shallow trench isolation structure;
removing a substrate region facing away from the shallow trench isolation structure by etching;
Depositing and forming a multi-layer photoelectric sensing region on one side of the isolation layer away from the shallow trench isolation structure;
Etching the multi-layer photoelectric sensing region to form a deep trench isolation region;
Sequentially depositing a first oxide layer and a stabilizing layer, wherein the first oxide layer and the stabilizing layer cover the bottom surface and the side wall of the deep trench isolation region and cover the top surface of the multi-layer photoelectric sensing region, the first oxide layer is a silicon oxide layer, and the stabilizing layer is a titanium nitride layer;
Depositing and forming an isolation medium layer in the deep trench isolation region, wherein the isolation medium layer is an aluminum layer;
Forming a grid structure layer on the multilayer photoelectric sensing region;
And removing the grid structure layer between the deep trench isolation structures to form a grid structure.
6. The method of claim 5, wherein the multi-layer photo-sensing region is formed by depositing a silicon boride layer, a silicon arsenide layer, and a silicon antimonide layer sequentially from one side of the isolation layer.
7. The method of claim 5, further comprising forming a filter structure between adjacent grid structures.
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