CN-224234082-U - Pixel sensor array

Abstract

The utility model provides a pixel sensor array including a photodiode in a substrate, a deep trench isolation structure laterally surrounding the photodiode in the substrate, a diffusion structure in a recess in the substrate, and a doped implant region in the substrate. The deep trench isolation structure includes a conformal liner, a dielectric layer over the conformal liner, and an elongated metal insert in the dielectric layer. A diffusion structure is over the photodiode and within an inner perimeter of the deep trench isolation structure, and a doped implant region is between the photodiode and the diffusion structure. The diffusion structure can be formed to distribute incident light for a particular optical wavelength and/or a wider range of optical bandwidths, which can improve the quantum effect of the pixel sensor.

Inventors

• HUANG ZHENGYU
• ZHUANG JUNHAO
• JIANG WEIJIE
• DING SHIFA

Assignees

• 台湾积体电路制造股份有限公司

Dates

Publication Date

20260512

Application Date

20250416

Priority Date

20240515

Claims (10)

1. 1. A pixel sensor array comprising a plurality of pixel electrodes, characterized by comprising the following steps: A photodiode in the substrate; a deep trench isolation structure laterally surrounding the photodiode in the substrate, comprising: A conformal liner; a dielectric layer over the conformal liner, and An elongated metal insert in the dielectric layer; A diffusion structure in a recess in the substrate, wherein the diffusion structure is above the photodiode and within an inner perimeter of the deep trench isolation structure, and A doped implant region in the substrate, wherein the doped implant region is between the photodiode and the diffusion structure.
2. 2. The pixel sensor array of claim 1, wherein the doped implant region comprises a blanket implant region extending between opposite sides of the inner perimeter of the deep trench isolation structure in a cross-sectional view of the pixel sensor array, and Wherein the blanket implant region extends between a top and a bottom of the recess in the substrate where the diffusion structure is located.
3. 3. The pixel sensor array of claim 1, wherein the doped implant region comprises a conformal implant region extending between opposite sides of the inner perimeter of the deep trench isolation structure in a cross-sectional view of the pixel sensor array, and Wherein the conformal implant region conforms to a cross-sectional profile of the recess in the substrate in which the diffusion structure is located.
4. 4. The pixel sensor array of claim 1, wherein the diffusion structure is in direct physical contact with the substrate in the recess, and Wherein the conformal liner extends over and above the diffusion structure.
5. 5. The pixel sensor array of claim 1, wherein the material of the elongated metal inserts is selected based on an operating wavelength range of incident light of the pixel sensor array.
6. 6. The pixel sensor array of claim 1, wherein the elongated metal inserts extend above a backside surface of the substrate.
7. 7. The pixel sensor array of claim 1, wherein the diffusion structure has a V-shaped cross-sectional profile, a circular cross-sectional profile, or a U-shaped cross-sectional profile.
8. 8. The pixel sensor array of claim 1, wherein the doped implant region extends between a top and a bottom of the recess in the substrate.
9. 9. The pixel sensor array of claim 1, further comprising: and a passivation layer over the deep trench isolation structure and over the diffusion structure.
10. 10. The pixel sensor array of claim 1, further comprising: A metal mesh structure over the deep trench isolation structure and around the photodiode, the metal mesh structure including an opening over the photodiode.

Description

Pixel sensor array Technical Field Embodiments of the present utility model relate to a semiconductor structure, and more particularly, to a pixel sensor array. Background Complementary metal oxide semiconductor (Complementary metal oxide semiconductor, CMOS) image sensors utilize photosensitive CMOS circuitry to convert light energy (e.g., photons) into electrical energy. The photosensitive CMOS circuit may include a photodiode formed in a silicon substrate. When the photodiode is exposed to light, an electric charge (referred to as a photocurrent) is induced in the photodiode. The photodiode may be coupled to a switching transistor for sampling the charge of the photodiode. The color can be determined by placing filters over the light sensitive CMOS circuitry. Disclosure of utility model Embodiments of the present utility model provide a pixel sensor array including a photodiode in a substrate, a deep trench isolation structure laterally surrounding the photodiode in the substrate, a diffusion structure in a recess in the substrate, and a doped implant region in the substrate. The deep trench isolation structure includes a conformal liner, a dielectric layer over the conformal liner, and an elongated metal insert in the dielectric layer. The diffusion structure is over the photodiode and within an inner perimeter of the deep trench isolation structure, and the doped implant region is between the photodiode and the diffusion structure. Based on the foregoing, embodiments of the present utility model form the metal insert after forming the diffusion structure to prevent the material of the metal insert from limiting the size and/or shape of the diffusion structure, which provides greater manufacturing flexibility in forming the diffusion structure. The greater flexibility in selecting the size and/or shape of the diffusing structure enables the diffusing structure to be formed to distribute incident light for a particular optical wavelength and/or a wider range of optical bandwidths. This may increase the quantum effect of the pixel sensor. Additionally and/or alternatively, forming the metal insert by planarization rather than etching enables use of a metal with high reflectivity for the metal insert. This may increase the reflectivity of the deep trench isolation structure, which may increase the optical isolation provided by the deep trench isolation structure. Furthermore, completely filling the recess with a dielectric material results in fewer semiconductor processing operations than partially filling the recess with a dielectric layer and then completely filling the recess after forming the metal insert, which may reduce the cost, complexity, and/or time for manufacturing the pixel sensor. In order to make the above features and advantages of embodiments of the present utility model more comprehensible, embodiments accompanied with figures are described in detail below. Drawings Fig. 1 is a diagram of an example of a pixel sensor as described herein. Fig. 2A-2C are diagrams of examples of image sensor devices described herein. Fig. 3A-3E are diagrams of examples of pixel sensors that may be included in a pixel sensor array of an image sensor device described herein. Fig. 4A-4E are diagrams of examples of pixel sensors that may be included in a pixel sensor array of an image sensor device described herein. Fig. 5A-5E are diagrams of exemplary embodiments of forming a circuit die (or portion thereof) as described herein. Fig. 6A-6F are diagrams of exemplary embodiments forming a sensor die (or portion thereof) as described herein. Fig. 7A and 7B are diagrams of exemplary embodiments forming an image sensor device (or a portion thereof) described herein. Fig. 8A-8I are diagrams of exemplary embodiments of pixel sensor arrays forming a sensor die (or a portion thereof) as described herein. Fig. 9A-9I are diagrams of exemplary embodiments of pixel sensor arrays forming a sensor die (or a portion thereof) as described herein. FIG. 10 is a flow chart of an example process associated with forming a pixel sensor array as described herein. FIG. 11 is a flow chart of an example process associated with forming a pixel sensor array as described herein. Detailed Description The following disclosure provides many different embodiments, or examples, for implementing different features of the disclosure. Specific examples of components and arrangements are set forth below to simplify the present disclosure. These are, of course, merely examples and are not intended to limit the scope of the present disclosure. For example, in the following description, a first feature is formed "on" or "over" a second feature, which may include embodiments in which the first feature and the second feature are formed in direct contact, as well as embodiments in which additional features are formed between the first feature and the second feature such that the first feature and the second feature are not in direct contact. In addition,