# US 10,319,816 B2 · Silicon germanium fin channel formation

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- Number: US 10,319,816 B2
- Document ID: US10319816B2
- Status: Granted
- Kind: B2
- Application number: 16/016,021
- Filed: 2018-06-22
- Published: 2018-10-18
- Granted: 2019-06-11
- Earliest claimed: 2015-07-15
- Assignees: International Business Machines Corporation; STMicroelectronics S.r.l.
- Applicants: International Business Machines Corporation; STMicroelectronics, Inc.
- Inventors: Hong He; Nicolas Loubet; Junli Wang
- Web page: https://patentgrep.com/patent/US10319816B2

## CPC

- H10D 30/751: {having composition variations in the channel regions}
- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H10D 30/0245: {by further thinning the channel after patterning the channel, e.g. using sacrificial oxidation on fins}
- H10D 30/62: Fin field-effect transistors [FinFET]
- H10D 62/832: being Group IV materials comprising two or more elements, e.g. SiGe
- H10D 62/834: further characterised by the dopants
- 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 64/021: {using multiple gate spacer layers, e.g. bilayered sidewall spacers}
- H10D 64/667: {the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN workfunction layers (having lateral variation H10D64/671)}
- H10P 14/3411: {Silicon, silicon germanium or germanium}
- H10P 14/3454: {Amorphous}
- H10P 14/6308: {of Group IV semiconductors}
- H10P 32/1412: {through the applied layer}
- H10P 32/171: {being group IV material}
- H10P 50/283: {by chemical means}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A fin field effect transistor includes a Si fin including a central portion between end portions of the fin, and a SiGe channel region disposed on the central portion of the fin. The SiGe channel region includes a facet free SiGe region having Ge atoms diffused into the Si fin and includes a same shape as the Si fin outside the central portion.

## Claims

### Claim 1

A fin field effect transistor, comprising:
a Si fin including a central portion between end portions of the fin; and
a SiGe channel region disposed on the central portion of the fin, the SiGe channel region including a facet free SiGe region having Ge atoms diffused into the Si fin and including a same shape as the Si fin outside the central portion.

### Claim 2 (depends on 1)

The transistor as recited in claim 1, wherein the SiGe channel region includes about 10 to about 100 at % Ge.

### Claim 3 (depends on 1)

The transistor as recited in claim 1, further comprising a gate structure formed over the central portion of the fin, wherein the gate structure includes a gate dielectric on the channel region, a gate conductor on the gate dielectric and a cap layer on the gate conductor.

### Claim 4 (depends on 3)

The transistor as recited in claim 3, wherein a vertical height of the cap layer is about half of a vertical height of the gate conductor.

### Claim 5 (depends on 3)

The transistor as recited in claim 3, wherein the gate conductor includes two or more conductive materials.

### Claim 6 (depends on 3)

The transistor as recited in claim 3, wherein the gate conductor includes a conductor, an intermediary metal and a work function metal.

### Claim 7 (depends on 6)

The transistor as recited in claim 6, wherein the conductor has a cross-sectional shape, the shape including a T-shaped cross section.

### Claim 8 (depends on 6)

The transistor as recited in claim 6, wherein the intermediary metal is formed over the work function metal.

### Claim 9 (depends on 6)

The transistor as recited in claim 6, wherein the cap layer contacts the gate conductor and the intermediary metal.

### Claim 10 (depends on 3)

The transistor as recited in claim 3, wherein the gate conductor includes a work function metal in contact with the gate dielectric layer.

### Claim 11 (depends on 10)

The transistor as recited in claim 10, further comprising an intermediary metal formed over the work function metal.

### Claim 12 (depends on 11)

The transistor as recited in claim 11, wherein the cap layer contacts the gate conductor and the intermediary metal.

### Claim 13 (depends on 10)

The transistor as recited in claim 10, wherein the work function metal contacts a bottom portion of the gate dielectric layer.

### Claim 14 (depends on 10)

The transistor as recited in claim 10, wherein the work function metal has a cross-sectional shape, the shape including a U-shaped channel.

### Claim 15 (depends on 1)

The transistor as recited in claim 1, wherein the SiGe channel with the same shape as the Si fin outside the central portion includes a rectangular shape.

### Claim 16

A fin field effect transistor, comprising:
a Si fin including a central portion between end portions of the fin;
a SiGe channel region disposed on the central portion of the fin, the SiGe channel region including a facet free SiGe region having Ge atoms diffused into the Si fin and including a same shape as the Si fin outside the central portion; and
source and drain regions formed on or in the fin on opposite sides of the SiGe channel region, wherein the SiGe channel region extends vertically from a top of the fin to a bottom of the fin.

### Claim 17 (depends on 16)

The transistor as recited in claim 16, wherein the SiGe channel region includes about 10 to about 100 at % Ge.

### Claim 18

A fin field effect transistor, comprising:
a Si fin including a central portion between end portions of the fin;
a gate structure formed over the central portion of the fin; and
a SiGe channel region disposed on the central portion of the fin corresponding to the gate structure, the SiGe channel region including a facet free SiGe region having Ge atoms diffused into the Si fin and including a same shape as the Si fin outside the central portion.

### Claim 19 (depends on 18)

The transistor as recited in claim 18, wherein the SiGe channel region includes about 10 to about 100 at % Ge.

### Claim 20 (depends on 19)

The transistor as recited in claim 19, wherein the gate conductor includes two or more conductive metals, and wherein the cap layer contacts the two or more conductive metals.