# US 2017/0256390 A1 · Semiconductor structure with etched fin structure

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- Number: US 2017/0256390 A1
- Document ID: US20170256390A1
- Status: Published application
- Kind: A1
- Application number: 15/599,225
- Filed: 2017-05-18
- Published: 2017-09-07
- Earliest claimed: 2014-12-19
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Shiang-Bau WANG
- Web page: https://patentgrep.com/patent/US20170256390A1

## CPC

- H10P 14/6304: {Formation by oxidation, e.g. oxidation of the substrate}
- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H10D 30/797: {being in source or drain regions, e.g. SiGe source or drain}
- H10D 62/82: Heterojunctions
- H10D 62/822: comprising only Group IV materials heterojunctions, e.g. Si/Ge heterojunctions
- H10D 64/017: {using dummy gates in processes wherein at least parts of the final gates are self-aligned to the dummy gates, i.e. replacement gate processes}
- H10D 64/691: {comprising metallic compounds, e.g. metal oxides or metal silicates (insulators comprising nitrogen H10D64/693)}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

Semiconductor structures are provided. The semiconductor structure includes a substrate and a first fin structure and a second fin structure formed over the substrate. The semiconductor structure further includes an isolation structure formed around the second fin structure and covering the first fin structure and a gate structure formed over the first fin structure and the second fin structure. The semiconductor structure further includes the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the gate structure and the first fin structure are separated by the isolation structure.

## Claims

### Claim 1

A semiconductor structure, comprising:
a substrate;
a first fin structure and a second fin structure formed over the substrate;
an isolation structure formed around the second fin structure and covering the first fin structure; and
a gate structure formed over the first fin structure and the second fin structure,
wherein the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the gate structure and the first fin structure are separated by the isolation structure.

### Claim 2 (depends on 1)

The semiconductor structure as claimed in claim 1, wherein the first fin structure has blunt corners at its top portion.

### Claim 3 (depends on 1)

The semiconductor structure as claimed in claim 1, further comprising:
an oxide structure formed over the first fin structure; and
a first sidewall layer formed on a sidewall of the oxide structure, wherein the first sidewall layer further extends onto a sidewall of the first fin structure.

### Claim 4 (depends on 3)

The semiconductor structure as claimed in claim 3, wherein the first sidewall layer is in direct contact with the gate structure.

### Claim 5 (depends on 4)

The method for manufacturing a semiconductor structure as claimed in claim 4, wherein the first sidewall layer is a nitride layer.

### Claim 6 (depends on 3)

The semiconductor structure as claimed in claim 3, further comprising:
a second sidewall layer formed over the first sidewall layer,
wherein the first sidewall layer and the second sidewall layer are both in direct contact with the gate structure.

### Claim 7 (depends on 6)

The semiconductor structure as claimed in claim 6, wherein the first sidewall layer is made of oxide and the second sidewall layer is made of nitride.

### Claim 8

A semiconductor structure, comprising:
a substrate;
a first fin structure and a second fin structure formed over the substrate;
an isolation structure formed around sidewalls of the second fin structure; and
a gate structure formed over the first fin structure and the second fin structure,
wherein the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the first fin structure has blunt corners at its top portion.

### Claim 9 (depends on 8)

The semiconductor structure as claimed in claim 8, wherein the top portion of the first fin structure is covered by the isolation structure.

### Claim 10 (depends on 8)

The semiconductor structure as claimed in claim 8, further comprising:
an oxide structure formed over the first fin structure, wherein the oxide structure is positioned between the first fin structure and the isolation structure.

### Claim 11 (depends on 10)

The semiconductor structure as claimed in claim 10, further comprising:
a first sidewall layer formed on sidewalls of the first fin structure, sidewalls of the oxide structure, and the sidewalls of the second fin structure.

### Claim 12 (depends on 11)

The semiconductor structure as claimed in claim 11, wherein the first sidewall layer is in direct contact with a bottom surface of the gate structure.

### Claim 13 (depends on 12)

The method for manufacturing a semiconductor structure as claimed in claim 12, wherein the first sidewall layer is a nitride layer.

### Claim 14 (depends on 10)

The semiconductor structure as claimed in claim 10, wherein the oxide structure is in contact with a bottom of the gate structure.

### Claim 15

A semiconductor structure, comprising:
a substrate;
a first fin structure and a second fin structure formed over the substrate;
an oxide structure formed over the first fin structure;
an isolation structure formed adjacent to the second fin structure and covering the oxide structure; and
a gate structure formed over the isolation structure and extending across the second fin structure,
wherein the gate structure and the first fin structure are separated by the isolation structure.

### Claim 16 (depends on 15)

The semiconductor structure as claimed in claim 15, wherein the first fin structure has blunt corners at its top portion.

### Claim 17 (depends on 15)

The semiconductor structure as claimed in claim 15, further comprising:
a first sidewall layer extending onto a sidewall of oxide structure, a sidewall of the first fin structure, and a sidewall of the second fin structure.

### Claim 18 (depends on 17)

The semiconductor structure as claimed in claim 17, further comprising:
a second sidewall layer formed over the first sidewall layer,
wherein the first sidewall layer and the second sidewall layer are both in direct contact with the gate structure.

### Claim 19 (depends on 15)

The semiconductor structure as claimed in claim 15, wherein a bottom surface of the gate structure is in direct contact with the second fin structure.

### Claim 20 (depends on 15)

The semiconductor structure as claimed in claim 15, wherein the oxide structure is in direct contact with the gate structure.