# US 7,608,872 B2 · Complementary metal oxide semiconductor image sensor and method for fabricating the same

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- Number: US 7,608,872 B2
- Document ID: US7608872B2
- Status: Granted
- Kind: B2
- Application number: 11/303,059
- Filed: 2005-12-13
- Published: 2007-03-15
- Granted: 2009-10-27
- Earliest claimed: 2005-09-14
- Inventors: Sang-Young Kim
- Web page: https://patentgrep.com/patent/US7608872B2

## CPC

- H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors
- H10F 39/014: {of CMOS image sensors}
- H10F 39/80: {Constructional details of 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 complementary metal oxide semiconductor (CMOS) device and a method for fabricating the same are provided. The CMOS image sensor includes: a first conductive type substrate including a trench; a channel stop layer formed by using a first conductive type epitaxial layer over an inner surface of the trench; a device isolation layer formed on the channel stop layer to fill the trench; a second conductive type photodiode formed in a portion of the substrate in one side of the channel stop layer; and a transfer gate structure formed on the substrate adjacent to the photodiode to transfer photo-electrons generated from the photodiode.

## Claims

### Claim 1

A complementary metal oxide semiconductor (CMOS) image sensor, comprising:
a first conductive type substrate including a trench;
a channel stop layer formed by using a first conductive type epitaxial layer over an inner surface of the trench;
a device isolation layer formed on the channel stop layer to fill the trench;
a second conductive type photodiode formed in a portion of the substrate in one side of the channel stop layer;
a transfer gate structure formed on the substrate adjacent to the photodiode to transfer photo-electrons generated from the photodiode; and
a floating diffusion region formed in a portion of the substrate opposite to the photodiode and adjacent to the transfer gate structure to receive the photo-electrons from the transfer gate structure,
wherein bottom portions of the channel stop Layer are located in a deeper position from the surface of the first conductive type substrate than bottom portions of the second conductive type photodiode.

### Claim 2 (depends on 1)

The CMOS image sensor of claim 1, further including a first conductive type impurity diffusion region on the substrate in which the photodiode is formed.

### Claim 3 (depends on 2)

The CMOS image sensor of claim 2, wherein the device isolation layer is formed with a predetermined height from a lower portion of the trench to prevent a conductive material of the transfer gate structure from remaining inside the trench.