# US 10,121,881 B2 · Semiconductor device and method for fabricating the same

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- Number: US 10,121,881 B2
- Document ID: US10121881B2
- Status: Granted
- Kind: B2
- Application number: 15/481,419
- Filed: 2017-04-06
- Published: 2017-09-14
- Granted: 2018-11-06
- Earliest claimed: 2016-03-08
- Assignees: United Microelectronics Corp.
- Applicants: United Microelectronics Corp.
- Inventors: Li-Wei Feng; Shih-Hung Tsai; Yi-Fan Li; Kun-Hsin Chen; Tong-Jyun Huang; Jyh-Shyang Jenq; Nan-Yuan Huang
- Web page: https://patentgrep.com/patent/US10121881B2

## CPC

- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H10D 30/62: Fin field-effect transistors [FinFET]
- H10D 30/751: {having composition variations in the channel regions}
- H10D 30/797: {being in source or drain regions, e.g. SiGe source or drain}
- H10D 30/798: {being provided in or under the channel regions}
- H10P 30/20: into semiconductor materials, e.g. for doping
- H10P 30/204: {into Group IV semiconductors}
- H10P 30/206: {into Group III-V semiconductors}
- H10P 30/208: {of electrically inactive species}
- H10P 30/21: {of electrically active species}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A semiconductor device preferably includes a substrate, a fin-shaped structure on the substrate, a buffer layer on the fin-shaped structure, and an epitaxial layer on the buffer layer. Preferably, the buffer layer is made of silicon germanium and including three or more than three elements. The buffer layer also includes dopants selected from the group consisting of P, As, Sb, Bi, C, and F.

## Claims

### Claim 1

A semiconductor device, comprising:
a substrate;
an active region and a peripheral region defined on the substrate, wherein a top surface of the substrate on the peripheral region is higher than a top surface of the substrate on the active region;
a fin-shaped structure on the substrate;
a buffer layer on top of the fin-shaped structure, wherein the buffer layer comprises three or more than three elements; and
an epitaxial layer on the buffer layer.

### Claim 2 (depends on 1)

The semiconductor device of claim 1, wherein the buffer layer comprises silicon and germanium.

### Claim 3 (depends on 1)

The semiconductor device of claim 1, wherein the buffer layer comprises dopants selected from the group consisting of P, As, Sb, Bi, C, and F.

### Claim 4 (depends on 1)

The semiconductor device of claim 1, wherein the buffer layer comprises dopants not carrying any charge.

### Claim 5 (depends on 1)

The semiconductor device of claim 1, wherein the buffer layer comprises dopants carrying charges.

### Claim 6 (depends on 1)

The semiconductor device of claim 1, wherein the epitaxial layer and the buffer layer comprise same material.

### Claim 7 (depends on 1)

The semiconductor device of claim 1, wherein the epitaxial layer and the buffer layer comprise different material.

### Claim 8 (depends on 1)

The semiconductor device of claim 1, wherein a top surface of the substrate on the peripheral region is even with a top surface of the epitaxial layer on the active region.

### Claim 9 (depends on 1)

The semiconductor device of claim 1, further comprising a well disposed in the substrate on the active region.

### Claim 10 (depends on 9)

The semiconductor device of claim 9, wherein the well and the buffer layer comprise same conductive type.

### Claim 11 (depends on 9)

The semiconductor device of claim 9, wherein a doping concentration of the buffer layer is higher than a doping concentration of the well.

### Claim 12 (depends on 1)

The semiconductor device of claim 1, further comprising a shallow trench isolation (STI) around the fin-shaped structure.

### Claim 13 (depends on 12)

The semiconductor device of claim 12, wherein a top surface of the STI is lower than a top surface of the buffer layer and higher than a bottom surface of the buffer layer.