# US 9,437,649 B2 · Semiconductor structure, method for forming the same and method for suppressing hot cluster

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,437,649 B2
- Document ID: US9437649B2
- Status: Granted
- Kind: B2
- Application number: 14/195,764
- Filed: 2014-03-03
- Published: 2014-09-04
- Granted: 2016-09-06
- Earliest claimed: 2013-03-04
- Assignees: Himax Imaging Limited
- Applicants: Himax Imaging, Inc.
- Inventors: Yang Wu; Feixia Yu; Chung-Wei Chang
- Web page: https://patentgrep.com/patent/US9437649B2

## CPC

- H10F 39/026: {Wafer-level processing}
- H10F 39/014: {of CMOS image sensors}
- H10F 39/182: {Colour image sensors}
- H10F 39/807: {Pixel isolation structures}
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION

## Abstract

A semiconductor structure for suppressing hot clusters includes a substrate of a first dopant concentration, an epitaxial layer having a second dopant concentration smaller than the first dopant concentration and directly disposed on the substrate, a dopant gradient region disposed in the epitaxial layer and having a gradient decreasing from the substrate to the epitaxial layer, a shallow trench isolation disposed between a first element region and a second element region, and a shallow trench doping region surrounding the shallow trench isolation and near the dopant gradient region to suppress a hot cluster formed by the first element region to jeopardize the second element region.

## Claims

### Claim 1

A semiconductor structure for suppressing a hot cluster, comprising:
a substrate of a first dopant concentration;
an epitaxial layer disposed on and directly contacting said substrate, and having a second dopant concentration smaller than said first dopant concentration;
a dopant gradient region disposed in said epitaxial layer and having a dopant gradient decreasing from said substrate to said epitaxial layer;
a first element region disposed in said epitaxial layer and comprising a first element doping region and a first element;
a second element region disposed in said epitaxial layer and comprising a second element doping region and a second element; and
a shallow trench isolation region disposed between said first element region and said second element region, and comprising a shallow trench isolation completely disposed inside said shallow trench isolation region, wherein said shallow trench isolation region is substantially adjacent to said dopant gradient region to suppress a hot cluster formed by said first element region jeopardizing said second element region.

### Claim 2 (depends on 1)

The semiconductor structure for suppressing a hot cluster of claim 1, wherein said first element and said second element are respectively a CMOS image sensor.

### Claim 3 (depends on 2)

The semiconductor structure for suppressing a hot cluster of claim 2, wherein said shallow trench isolation region substantially overlap said dopant gradient region to suppress a dark current travelling from said first element region through said epitaxial layer to said second element region.

### Claim 4 (depends on 1)

The semiconductor structure for suppressing a hot cluster of claim 1, wherein said shallow trench isolation region is closer to said dopant gradient region than at least one of said first element region and said second element region.