# US 2018/0323302 A1 · Method for fabricating a curve on sidewalls of a fin-shaped structure

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- Number: US 2018/0323302 A1
- Document ID: US20180323302A1
- Status: Published application
- Kind: A1
- Application number: 16/036,831
- Filed: 2018-07-16
- Published: 2018-11-08
- Earliest claimed: 2017-03-23
- Assignees: United Microelectronics Corp.
- Applicants: United Microelectronics Corp.
- Inventors: Yi-Fan Li; I-Cheng Hu; Chun-Jen Chen; Tien-I Wu; Yu-Shu Lin; Chun-Yuan Wu
- Web page: https://patentgrep.com/patent/US20180323302A1

## CPC

- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 30/6211: {having fin-shaped semiconductor bodies integral with the bulk semiconductor substrates}
- H10D 30/6212: {having fin-shaped semiconductor bodies having non-rectangular cross-sections}
- H10D 62/221: {of FETs}
- H10D 84/0158: {the components including FinFETs}
- H10D 84/016: {the components including vertical IGFETs}
- H10D 84/0193: {the components including FinFETs}
- H10D 84/834: {comprising FinFETs}
- H10P 50/242: {of Group IV materials}
- H10P 50/283: {by chemical means}
- H10P 50/694: {characterised by their behaviour during the process, e.g. soluble masks or redeposited masks}
- H10W 10/011: {of isolation regions comprising dielectric materials}
- H10W 10/0121: {in regions recessed from the surface, e.g. in trenches or grooves}
- H10W 10/014: {using trench refilling with dielectric materials, e.g. shallow trench isolations}
- H10W 10/10: Isolation regions comprising dielectric materials
- H10W 10/13: formed using local oxidation of silicon [LOCOS], e.g. sealed interface localised oxidation [SILO] or side-wall mask isolation [SWAMI]
- H10W 10/17: formed using trench refilling with dielectric materials, e.g. shallow trench isolations
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A method for fabricating semiconductor device includes the steps of: forming a fin-shaped structure on a substrate; forming a shallow trench isolation (STI) around the fin-shaped structure; forming a liner on the fin-shaped structure; and removing the liner and part of the fin-shaped structure so that a sidewall of the fin-shaped structure comprises a curve. Moreover, the method includes forming an epitaxial layer around the sidewall of the fin-shaped structure while a top surface of the fin-shaped structure is exposed.

## Claims

### Claim 1

A method for fabricating semiconductor device, comprising:
forming a fin-shaped structure on a substrate;
forming a shallow trench isolation (STI) around the fin-shaped structure; and
removing part of the fin-shaped structure so that a sidewall of the fin-shaped structure comprises a curve.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
forming a liner on the fin-shaped structure; and
removing the liner and part of the fin-shaped structure to form the curve.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
using an etching gas to remove the liner completely and part of the fin-shaped structure, wherein the etching gas is selected from the group consisting of CH4 and CH2F2.

### Claim 4 (depends on 2)

The method of claim 2, wherein the liner comprises silicon oxide.

### Claim 5 (depends on 1)

The method of claim 1, further comprising forming an epitaxial layer around the sidewall of the fin-shaped structure while a top surface of the fin-shaped structure is exposed.

### Claim 6 (depends on 5)

The method of claim 5, further comprising using a gas selected from the group consisting of dichlorosilane (DCS), GeH4, and HCl to form the epitaxial layer.

### Claim 7 (depends on 5)

The method of claim 5, further comprising using a gas selected from the group consisting of SiH4, GeH4, and HCl to form the epitaxial layer.

### Claim 8 (depends on 5)

The method of claim 5, wherein the epitaxial layer comprises an inner sidewall overlapping the sidewall of the fin-shaped structure and an outer sidewall opposite to the inner sidewall.

### Claim 9 (depends on 8)

The method of claim 8, wherein the outer sidewall comprises a planar portion extending from the bottom surface of the fin-shaped structure upward and a curved portion extending from the top surface of the fin-shaped structure downward.

### Claim 10 (depends on 1)

The method of claim 1, wherein the curve comprises a planar portion extending from the top surface of fin-shaped structure downward and a curved portion extending from the bottom surface of the fin-shaped structure upward.