# US 12,218,222 B2 · FinFET device and method of forming same

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- Number: US 12,218,222 B2
- Document ID: US12218222B2
- Status: Granted
- Kind: B2
- Application number: 17/805,581
- Filed: 2022-06-06
- Published: 2022-09-22
- Granted: 2025-02-04
- Earliest claimed: 2018-10-31
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Chien-Wei Lee; Che-Yu Lin; Hsueh-Chang Sung; Yee-Chia Yeo
- Web page: https://patentgrep.com/patent/US12218222B2

## CPC

- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H01J 37/32724: {Temperature}
- H10D 30/6211: {having fin-shaped semiconductor bodies integral with the bulk semiconductor substrates}
- H10D 62/021: {Forming source or drain recesses by etching e.g. recessing by etching and then refilling}
- H10D 62/151: {of IGFETs (of IGFETs having LDD or DDD structure H10D30/601; of thin film transistors H10D30/6713)}
- H10D 62/405: {Orientations of crystalline planes}
- 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 84/0193: {the components including FinFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 84/83135: {the IGFETs characterised by having different gate conductor materials or different gate conductor implants}
- H10D 84/8314: {the IGFETs characterised by having gate insulating layers with different properties}
- H10D 84/853: {comprising FinFETs}
- H10P 50/242: {of Group IV materials}
- H10P 70/20: {Cleaning during device manufacture}
- H10P 72/0421: {for drying etching}
- H10P 72/0432: {mainly by conduction}
- H10P 72/7616: {characterised by a coating, a hardness or a material}
- H10W 10/014: {using trench refilling with dielectric materials, e.g. shallow trench isolations}
- H10W 10/17: formed using trench refilling with dielectric materials, e.g. shallow trench isolations
- H01J 37/321: {the radio frequency energy being inductively coupled to the plasma}
- H01J 37/32449: {Gas control, e.g. control of the gas flow}
- H01J 2237/334: Etching
- H01J 2237/335: Cleaning
- H10D 30/0227: {having both lightly-doped source and drain extensions and source and drain regions self-aligned to the sides of the gate, e.g. lightly-doped drain [LDD] MOSFET or double-diffused drain [DDD] MOSFET}
- H10D 30/6219: {characterised by the source or drain electrodes}
- H10D 30/797: {being in source or drain regions, e.g. SiGe source or drain}
- H10D 62/822: comprising only Group IV materials heterojunctions, e.g. Si/Ge heterojunctions
- H10D 64/021: {using multiple gate spacer layers, e.g. bilayered sidewall spacers}
- H10P 30/204: {into Group IV semiconductors}
- H10P 30/21: {of electrically active species}
- H10P 30/22: using masks
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- 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 includes forming a fin over a substrate, forming an isolation region adjacent the fin, forming a dummy gate structure over the fin, and recessing the fin adjacent the dummy gate structure to form a first recess using a first etching process. The method also includes performing a plasma clean process on the first recess, the plasma clean process including placing the substrate on a holder disposed in a process chamber, heating the holder to a process temperature between 300° C. and 1000° C., introducing hydrogen gas into a plasma generation chamber connected to the process chamber, igniting a plasma within the plasma generation chamber to form hydrogen radicals, and exposing surfaces of the recess to the hydrogen radicals. The method also includes epitaxially growing a source/drain region in the first recess.

## Claims

### Claim 1

A system for performing a plasma cleaning process, comprising:
a process chamber;
a plasma generation chamber separated from the process chamber;
a showerhead located within the process chamber, wherein the showerhead is connected to the plasma generation chamber by a plurality of conduits, wherein the showerhead comprises a stack of gas distribution plates, wherein each gas distribution plate is separated from the process chamber, wherein each gas distribution plate is laterally separated from interior sidewalls of the process chamber, wherein each gas distribution plate comprises a plurality of openings, wherein the plurality of openings of each gas distribution plate are laterally offset from the plurality of openings of a neighboring gas distribution plate, wherein each gas distribution plate is electrically grounded; and
a holder disposed within the process chamber and configured to hold a wafer, the holder comprising a heating element, wherein the heating element is configured to generate a process temperature within the process chamber between 300° C. and 1000° C. during the plasma cleaning process.

### Claim 2 (depends on 1)

The system of claim 1 further comprising a source of hydrogen gas connected to the plasma generation chamber, wherein the plasma generation chamber is configured to generate hydrogen radicals from the hydrogen gas.

### Claim 3 (depends on 1)

The system of claim 1, wherein the holder comprises a holder material tolerant to a process temperature of 1000° C.

### Claim 4 (depends on 3)

The system of claim 3, wherein the holder material comprises an aluminum nitride material.

### Claim 5 (depends on 1)

The system of claim 1, wherein at least one gas distribution plate comprises openings that are more closely spaced in regions near an edge of that gas distribution plate than in regions near a center of that gas distribution plate.

### Claim 6 (depends on 1)

The system of claim 1, wherein the plurality of openings of at least one gas distribution plate comprises first openings having a first diameter in first regions near an edge of that gas distribution plate and second openings having a second diameter in second regions near a center of that gas distribution plate, wherein the first diameter is different from the second diameter, wherein the second regions near the center of that gas distribution plate are free of the first openings.

### Claim 7 (depends on 6)

The system of claim 6, wherein the first diameter is greater than the second diameter.

### Claim 8 (depends on 6)

The system of claim 6, wherein the plurality of openings of that gas distribution plate further comprises third openings having a third diameter in third regions between the first regions and the second regions, wherein the third diameter is between the first diameter and the second diameter.

### Claim 9

A system, comprising:
a plasma generation chamber operable to ignite a gas within into plasma products;
a process chamber separated from the plasma generation chamber, wherein interior surfaces of the process chamber are coated in a metallic protective material;
a showerhead within the process chamber, wherein the showerhead comprises a gas distribution plate at a bottom side of the showerhead;
a primary conduit coupled to the plasma generation chamber and to a top side of the showerhead, wherein the primary conduit is configured to introduce plasma products from the plasma generation chamber into the showerhead at the top of the showerhead;
a plurality of secondary conduits coupled to the plasma generation chamber and to a sidewall of the showerhead, wherein the plurality of secondary conduits are configured to transport plasma products from the plasma generation chamber into the showerhead at the sidewall of the showerhead; and
a platform within the process chamber, wherein the platform is coated in the metallic protective material.

### Claim 10 (depends on 9)

The system of claim 9, wherein the plurality of secondary conduits are coupled to the primary conduit.

### Claim 11 (depends on 9)

The system of claim 9, wherein the plurality of secondary conduits are coupled to the plasma generation chamber.

### Claim 12 (depends on 9)

The system of claim 9, wherein the secondary conduits are arranged radially around the sidewall of the showerhead.

### Claim 13 (depends on 9)

The system of claim 9, wherein the secondary conduits direct the plasma products toward a center of the showerhead.

### Claim 14 (depends on 9)

The system of claim 9, wherein the secondary conduits direct the plasma products in directions that are laterally offset from a center of the showerhead.

### Claim 15 (depends on 9)

The system of claim 9, wherein the gas distribution plate comprises openings that have a greater density near an edge of the gas distribution plate than near a center of the gas distribution plate.

### Claim 16 (depends on 9)

The system of claim 9, wherein the metallic protective material comprises iron, nickel, or cobalt.

### Claim 17

A plasma etching system, comprising:
a hydrogen gas supply connected to a plasma generator chamber, wherein the plasma generator chamber is configured to generate plasma products from hydrogen gas, wherein the plasma products comprise hydrogen radicals and hydrogen ions;
a showerhead comprising a plurality of distribution plates, wherein neighboring distribution plates are vertically separated, wherein each distribution plate comprises a plurality of apertures arranged in a plurality of concentric ring formations, wherein each distribution plate is electrically grounded, wherein the showerhead is configured to filter hydrogen ions out of the plasma products;
a first conduit physically connected to a first surface of the showerhead, wherein the first conduit is configured to transport plasma products from the plasma generator chamber to the plurality of distribution plates within the showerhead;
a second conduit physically connected to a second surface of the showerhead, wherein the second conduit is configured to transport plasma products from the plasma generator chamber to the plurality of distribution plates within the showerhead.

### Claim 18 (depends on 17)

The plasma etching system of claim 17 further comprising a magnetic filter coupled to the first conduit.

### Claim 19 (depends on 17)

The plasma etching system of claim 17, wherein the first surface is perpendicular to the second surface.

### Claim 20 (depends on 17)

The plasma etching system of claim 17, wherein the plurality of distribution plates comprises at least three distribution plates.