# US 12,224,330 B2 · Silicide structures in transistors and methods of forming

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- Number: US 12,224,330 B2
- Document ID: US12224330B2
- Status: Granted
- Kind: B2
- Application number: 18/520,326
- Filed: 2023-11-27
- Published: 2024-03-21
- Granted: 2025-02-11
- Earliest claimed: 2020-05-22
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Kai-Di Tzeng; Chen-Ming Lee; Fu-Kai Yang; Mei-Yun Wang
- Web page: https://patentgrep.com/patent/US12224330B2

## CPC

- H10D 64/0112: {using conductive layers comprising silicides}
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10D 30/024: {of fin field-effect transistors [FinFET]}
- H10D 30/62: Fin field-effect transistors [FinFET]
- H10D 30/6219: {characterised by the source or drain electrodes}
- H10D 64/01: Manufacture or treatment
- 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 84/017: {Manufacturing their source or drain regions, e.g. silicided source or drain regions}
- H10D 84/0193: {the components including FinFETs}
- H10D 84/038: {using silicon technology, e.g. SiGe}
- H10D 84/853: {comprising FinFETs}
- H10P 14/43: Chemical deposition, e.g. chemical vapour deposition [CVD]
- H10P 14/432: {using selective deposition}
- H10W 20/033: {in openings in dielectrics}
- H10W 20/048: {by using plasmas or gaseous environments, e.g. by nitriding}
- H10D 84/0149: {Manufacturing their interconnections or electrodes, e.g. source or drain electrodes}
- 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 device includes a gate stack; a gate spacer on a sidewall of the gate stack; a source/drain region adjacent the gate stack; a silicide; and a source/drain contact electrically connected to the source/drain region through the silicide. The silicide includes a conformal first portion in the source/drain region, the conformal first portion comprising a metal and silicon; and a conformal second portion over the conformal first portion, the conformal second portion further disposed on a sidewall of the gate spacer, the conformal second portion comprising the metal, silicon, and nitrogen.

## Claims

### Claim 1

A method comprising:
patterning an opening through an interlayer dielectric (ILD), wherein the opening exposes a surface of a source/drain region;
forming a silicide in the opening, wherein forming the silicide comprises:
performing a first deposition process to form a first metal-comprising portion on the source/drain region;
performing a second deposition process to form a second metal-comprising portion on the first metal-comprising portion; and
performing a passivation treatment on the second metal-comprising portion to convert the second metal-comprising portion to a nitride; and
forming a source/drain contact in the opening over the silicide.

### Claim 2 (depends on 1)

The method of claim 1, wherein performing the first deposition process comprises performing a first plasma process to convert TiCl4 to TiCl3 and TiCl2, an amount of TiCl3 being greater than TiCl2 in the first deposition process.

### Claim 3 (depends on 2)

The method of claim 2, wherein performing the second deposition process comprises performing a second plasma process to convert TiCl4 to TiCl3 and TiCl2, an amount of TiCl3 being less than TiCl2 in the second deposition process.

### Claim 4 (depends on 3)

The method of claim 3, wherein a radio-frequency (RF) power of the first deposition process is lower than a RF power of the second deposition process.

### Claim 5 (depends on 3)

The method of claim 3, wherein a pressure of the first deposition process is lower than a pressure of the second deposition process.

### Claim 6 (depends on 3)

The method of claim 3, wherein a gas flow of the first deposition process is lower than a gas flow of the second deposition process.

### Claim 7 (depends on 1)

The method of claim 1, wherein performing the passivation treatment comprises a third plasma process.

### Claim 8 (depends on 1)

The method of claim 1, wherein the first deposition process and the second deposition process are each performed at a temperature of at least 400° C.

### Claim 9 (depends on 8)

The method of claim 8, wherein no separate annealing process is performed between performing the passivation treatment and forming the source/drain contact.

### Claim 10 (depends on 1)

The method of claim 1, wherein the first deposition process deposits the first metal-comprising portion to have a greater thickness than the second deposition process deposits the second metal-comprising portion.

### Claim 11

A method comprising:
etching an opening through a dielectric layer to expose a source/drain region; and
forming a silicide in the opening, the silicide comprising:
a first portion extending into the source/drain region, the first portion comprising a metal and silicon; and
a second portion over the first portion, the second portion further disposed on a sidewall of the opening, the second portion comprising the metal, silicon, and nitrogen, wherein the silicide further comprises chlorine.

### Claim 12 (depends on 11)

The method of claim 11, wherein the metal is titanium.

### Claim 13 (depends on 11)

The method of claim 11, wherein a chlorine concentration of silicide is less than 0.5 at %.

### Claim 14 (depends on 11)

The method of claim 11, wherein the first portion of the silicide comprises chlorine.

### Claim 15 (depends on 11)

The method of claim 11, wherein the second portion of the silicide comprises chlorine.

### Claim 16

A method comprising:
exposing a surface of a source/drain region through an opening in a dielectric layer;
forming a silicide in the opening, wherein forming the silicide comprises:
performing a first deposition process to form a first titanium-comprising portion of the silicide on a surface of the source/drain region;
performing a second deposition process to form a second titanium-comprising portion of the silicide on the first titanium-comprising portion, wherein the second deposition process has a higher power, pressure, gas flow, or a combination thereof than the first deposition process; and
depositing a source/drain contact in the opening over the silicide.

### Claim 17 (depends on 16)

The method of claim 16, wherein the second deposition process further forms the second titanium-comprising portion of the silicide on sidewalls of the opening.

### Claim 18 (depends on 16)

The method of claim 16, wherein forming the silicide in the opening further comprises performing a nitridation process on the second titanium-comprising portion of the silicide.

### Claim 19 (depends on 16)

The method of claim 16, wherein the first deposition process comprises converting TiCl4 to TiCl3.

### Claim 20 (depends on 16)

The method of claim 16, wherein the second deposition process comprises converting TiCl4 to TiCl2.