CN-122002930-A - Image sensor color film manufacturing process and image sensor

CN122002930ACN 122002930 ACN122002930 ACN 122002930ACN-122002930-A

Abstract

The application discloses a manufacturing process of a color film of an image sensor and the image sensor, which belong to the field of manufacturing processes of semiconductor integrated circuits, wherein the process comprises the steps of providing an image sensor wafer; the image sensor wafer comprises at least one image sensor chip of an unprocessed color film, a first structure and a second structure are respectively formed by carrying out differentiation treatment on a target area and a non-target area of the surface of the image sensor wafer, the first structure at least comprises a color layer, the second structure at least comprises a color material residual layer, and the color material residual layer is removed based on the difference of the first structure and the second structure to form the color filter. The application can selectively remove the color interference outside the target color layer, restore the original color, effectively reduce the color mixing phenomenon among different color layers, and improve the color purity of the color film of the image sensor, thereby greatly improving the optical quantum efficiency.

Inventors

WU DAWEI
WANG WEI
WANG YONG

Assignees

成都微光集电科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (11)

1. The manufacturing process of the color film of the image sensor is characterized by comprising the following steps of: providing an image sensor wafer, wherein the image sensor wafer comprises at least one image sensor chip with an unprocessed color film; Performing differentiation processing on a target area and a non-target area on the surface of the image sensor wafer to respectively form a first structure and a second structure, wherein the first structure at least comprises a color layer; and removing the residual layer of the color material based on the difference between the first structure and the second structure to form a color filter.
2. The process for manufacturing the color film of the image sensor according to claim 1, wherein the performing the differentiation processing on the target area and the non-target area of the surface of the image sensor wafer to form the first structure and the second structure respectively includes: forming the color layer in the target area of the surface of the image sensor wafer by adopting a photoetching process, and forming the color material residual layer in the non-target area of the surface of the image sensor wafer, wherein the color layer forms the first structure; correspondingly, the removing the color material residual layer based on the difference between the first structure and the second structure to form a color filter comprises: And carrying out slight ashing treatment on the surface of the image sensor wafer based on the thickness difference of the first structure and the second structure, removing the residual layer of the color material, and removing part of the color layer with the thickness to form the color filter.
3. The process of claim 2, wherein the performing a light ashing process on the surface of the image sensor wafer based on the thickness difference between the first structure and the second structure, removing the residual layer of color material, and removing a portion of the color layer, after forming the color filter, comprises: and forming a nanoscale transparent protective layer on the surface of the image sensor wafer with the color filter.
4. The process for manufacturing the color film of the image sensor according to claim 1, wherein the performing the differentiation processing on the target area and the non-target area of the surface of the image sensor wafer to form the first structure and the second structure respectively includes: Forming a sacrificial layer on the non-target area of the surface of the image sensor wafer by adopting a first photoetching process; Forming the color layer on the target area of the surface of the image sensor wafer with the sacrificial layer by adopting a second photoetching process, and forming the color material residual layer on the surface of the sacrificial layer in the non-target area; the first photoetching process and the second photoetching process adopt the same photomask, the color layer forms the first structure, and the sacrificial layer and the color material residual layer which are arranged in a stacked way form the second structure; correspondingly, the removing the color material residual layer based on the difference between the first structure and the second structure to form a color filter comprises: And removing the sacrificial layer based on the structural difference of the first structure and the second structure to remove the residual layer of the color material carried by the sacrificial layer, thereby forming the color filter.
5. The process of claim 4, wherein forming a sacrificial layer on the non-target area of the image sensor wafer surface using a first photolithography process comprises: coating a transparent layer on the surface of the image sensor wafer; Exposing the transparent layer based on the photomask, wherein the transparent layer of the non-target area on the surface of the image sensor wafer after exposure has a first state, and the transparent layer of the target area has a second state, and the first state is opposite to the second state; And developing the transparent layer after exposure by adopting a first developing solution, and dissolving the transparent layer with the second state to form the sacrificial layer.
6. The process of claim 5, wherein forming the color layer on the target area of the image sensor wafer surface having the sacrificial layer and forming the residual layer of color material on the sacrificial layer surface of the non-target area using a second photolithography process comprises: coating the color layer on the surface of the image sensor wafer with the sacrificial layer, wherein the color layer and the transparent layer have opposite photosensitive characteristics; Exposing the color layer based on the same photomask, wherein the color layer of the non-target area of the surface of the image sensor wafer after exposure has the second state, and the color layer of the target area has the first state; And developing the exposed color layer by adopting a second developing solution, dissolving the color layer in the second state, forming the color layer in the target area, and forming the residual color material layer on the surface of the sacrificial layer in the non-target area, wherein the second developing solution and the first developing solution have the same dissolving characteristic.
7. The process of claim 5, wherein forming the color layer on the target area of the image sensor wafer surface having the sacrificial layer and forming the residual layer of color material on the sacrificial layer surface of the non-target area using a second photolithography process comprises: Coating the color layer on the surface of the image sensor wafer with the sacrificial layer, wherein the color layer and the transparent layer have the same photosensitive characteristic; Exposing the color layer based on the same photomask, wherein the color layer of the non-target area of the surface of the image sensor wafer after exposure has the first state, and the color layer of the target area has the second state; And developing the exposed color layer by adopting a second developing solution, dissolving the color layer in the first state, forming the color layer in the target area, and forming the residual color material layer on the surface of the sacrificial layer in the non-target area, wherein the second developing solution and the first developing solution have opposite dissolving characteristics.
8. The process for manufacturing the color film of the image sensor according to claim 4, wherein the material of the sacrificial layer comprises a transparent photoresist, the transparent photoresist comprises 2-heptanone, the stripping solution comprises dimethyl sulfoxide and N-methylpyrrolidone, and the removing the sacrificial layer comprises: dissolving by interaction of the dimethyl sulfoxide and the N-methyl pyrrolidone of the stripping liquid with the 2-heptanone of the sacrificial layer; The dissolved substances were removed by pure water.
9. The process for manufacturing the color film of the image sensor according to claim 4, wherein the material of the sacrificial layer comprises a thermal decomposition material or a photo decomposition material, and the removing the sacrificial layer comprises: the sacrificial layer is decomposed or volatilized by heat treatment or ultraviolet irradiation.
10. The process of claim 1, wherein the removing the residual layer of color material based on the difference between the first structure and the second structure, after forming the color filter, further comprises: and repeating the steps of performing differentiation processing on the target area and the non-target area of the surface of the image sensor wafer to form a first structure and a second structure respectively, and removing the residual layer of the color material based on the difference between the first structure and the second structure to form a color filter, wherein the color filters with different colors are formed in different areas of the surface of the image sensor wafer.
11. An image sensor, which is characterized by comprising the image sensor color film prepared by the image sensor color film manufacturing process according to any one of claims 1 to 10.

Description

Image sensor color film manufacturing process and image sensor Technical Field The present application relates to the field of semiconductor integrated circuit manufacturing processes, and in particular, to a color film manufacturing process for an image sensor and an image sensor. Background With the rapid development of the fields of smart phones, automatic driving, security monitoring, medical imaging, the Internet of things and the like, the performance requirements of the market on the image sensor are increasingly improved. The core performance metrics of the image sensor include higher resolution, faster frame rate, lower noise, and better photosensitivity. The photosensitivity is directly determined by the quantum efficiency of the pixel, and one of the quantum efficiency losses is the light loss of the color filter, namely, in order to realize color imaging, red, green and blue filters are integrated above the pixel, and the filters can selectively absorb other color light, so that part of incident light is wasted. For example, a red filter absorbs green and blue light, allowing only red light to pass through, with an upper limit on its theoretical light transmittance. How to maximize the optical quantum efficiency under the existing color filter technology is a technical problem that needs to be solved by those skilled in the art at present. In the prior art, the corresponding color filters are processed by the conventional photoetching process, and the corresponding color filters can be processed by the mature manufacturing scheme to enable light of different wave bands to pass through corresponding pixels, but in the actual processing process, the processing sequences of the color filters of different colors are different, and as the photoetching process can not completely remove the film layer of the non-target area of the current color filter, residues are generated at the bottoms or the tops of the color filters of other colors, so that the optical quantum efficiency is affected. Therefore, how to completely remove the residual effect from the bottom or top of the different color filters and other color filters results in lower optical quantum efficiency is a technical problem that needs to be solved by those skilled in the art. Disclosure of Invention The application aims to provide a manufacturing process of a color film of an image sensor and the image sensor, which can selectively remove color interference except a target color layer, thereby greatly improving optical quantum efficiency. In order to achieve the above object, the present application provides a process for manufacturing a color film of an image sensor, comprising: providing an image sensor wafer, wherein the image sensor wafer comprises at least one image sensor chip with an unprocessed color film; Performing differentiation processing on a target area and a non-target area on the surface of the image sensor wafer to respectively form a first structure and a second structure, wherein the first structure at least comprises a color layer; and removing the residual layer of the color material based on the difference between the first structure and the second structure to form a color filter. Optionally, the performing differentiation processing on the target area and the non-target area on the surface of the image sensor wafer to form a first structure and a second structure respectively includes: forming the color layer in the target area of the surface of the image sensor wafer by adopting a photoetching process, and forming the color material residual layer in the non-target area of the surface of the image sensor wafer, wherein the color layer forms the first structure; correspondingly, the removing the color material residual layer based on the difference between the first structure and the second structure to form a color filter comprises: And carrying out slight ashing treatment on the surface of the image sensor wafer based on the thickness difference of the first structure and the second structure, removing the residual layer of the color material, and removing part of the color layer with the thickness to form the color filter. Optionally, the performing a slight ashing process on the surface of the image sensor wafer based on the thickness difference between the first structure and the second structure, removing the residual layer of the color material, and removing a part of the thickness of the color layer, after forming the color filter, includes: and forming a nanoscale transparent protective layer on the surface of the image sensor wafer with the color filter. Optionally, the performing differentiation processing on the target area and the non-target area on the surface of the image sensor wafer to form a first structure and a second structure respectively includes: Forming a sacrificial layer on the non-target area of the surface of the image sensor wafer by adopting a first photoetching process; Forming the c