# US 8,785,310 B2 · Method of forming conformal metal silicide films

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- Number: US 8,785,310 B2
- Document ID: US8785310B2
- Status: Granted
- Kind: B2
- Application number: 13/427,343
- Filed: 2012-03-22
- Published: 2013-08-01
- Granted: 2014-07-22
- Earliest claimed: 2012-01-27
- Assignees: Tokyo Electron Limited
- Applicants: Toshio Hasegawa; Kunihiro Tada; Hideaki Yamasaki; David L. O'Meara; Gerrit J. Leusink
- Inventors: Toshio Hasegawa; Kunihiro Tada; Hideaki Yamasaki; David L. O'Meara; Gerrit J. Leusink
- Web page: https://patentgrep.com/patent/US8785310B2

## CPC

- H10W 20/023: {the interconnections being through-semiconductor vias}
- C23C 16/42: Silicides
- C23C 16/45538: {Plasma being used continuously during the ALD cycle}
- H10D 1/047: {of conductor-insulator-semiconductor capacitors, e.g. trench capacitors}
- H10P 14/432: {using selective deposition}
- H10W 20/0245: {comprising use of blind vias during the manufacture}
- H10W 20/0261: {characterised by the filling method or the material of the conductive fill}
- H10W 20/049: {by diffusing alloying elements}
- H10D 1/042: {using deposition processes to form electrode extensions}
- H10D 1/716: {having vertical extensions}
- H10D 64/0112: {using conductive layers comprising silicides}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method is provided for forming a metal silicide layer on a substrate. According to one embodiment the method includes providing the substrate in a process chamber, exposing the substrate at a first substrate temperature to a plasma generated from a deposition gas containing a metal precursor, where the plasma exposure forms a conformal metal-containing layer on the substrate in a self-limiting process. The method further includes exposing the metal-containing layer at a second substrate temperature to a reducing gas in the absence of a plasma, where the exposing steps are alternatively performed at least once to form the metal silicide layer, and the deposition gas does not contain the reducing gas. The method provides conformal metal silicide formation in deep trenches with high aspect ratios.

## Claims

### Claim 1

A method of forming a metal silicide layer on a substrate, comprising:
a) providing the substrate in a process chamber;
b) exposing the substrate at a first substrate temperature to a plasma generated from a deposition gas containing a metal precursor, wherein the plasma exposure forms a conformal metal-containing layer on the substrate in a self-limiting process; and
c) exposing the metal-containing layer at a second substrate temperature to a reducing gas in the absence of a plasma, wherein b) and c) are alternatively performed at least once to form the metal silicide layer, and wherein the deposition gas does not contain the reducing gas.

### Claim 2 (depends on 1)

The method of claim 1, wherein the metal-precursor contains a titanium halide, a molybdenum halide, a tungsten halide, a tantalum halide, or a vanadium halide, or a combination of two or more thereof.

### Claim 3 (depends on 1)

The method of claim 1, wherein the metal silicide layer comprises titanium silicide, molybdenum silicide, tungsten silicide, tantalum silicide, or vanadium silicide, or a combination of two or more thereof.

### Claim 4 (depends on 1)

The method of claim 1, wherein the metal silicide layer is conformally deposited over the surfaces of a deep trench formed in the substrate.

### Claim 5 (depends on 4)

The method of claim 4, wherein the deep trench has a width between about 50 nm and 100 nm, a depth between about 2000 nm and 5000 nm, and an aspect ratio between about 40:1 and about 100:1.

### Claim 6 (depends on 1)

The method of claim 1, wherein the metal precursor comprises a titanium halide, the reducing gas comprises H2, and the metal silicide layer comprises titanium silicide.

### Claim 7 (depends on 6)

The method of claim 6, wherein the first and second substrate temperatures are between about 450° C. and about 650° C.

### Claim 8

A method of forming a metal silicide film on a substrate, comprising:
a) providing the substrate in a process chamber;
b) exposing the substrate at a first substrate temperature to a plasma generated from a deposition gas containing a metal precursor, wherein the plasma exposure deposits a conformal metal-containing layer on the substrate in a self-limiting process;
c) exposing the metal-containing layer at a second substrate temperature to a reducing gas in the absence of a plasma, wherein b) and c) are alternatively performed at least once to form a metal film on the substrate, and wherein the deposition gas does not contain the reducing gas; and
d) annealing the substrate at a third substrate temperature to form the metal silicide film, wherein the third substrate temperature is greater than the second substrate temperature.

### Claim 9 (depends on 8)

The method of claim 8, wherein d) further comprises:
depositing silicon on the metal film prior to the annealing.

### Claim 10 (depends on 8)

The method of claim 8, wherein the deposition gas comprises a titanium halide, a molybdenum halide, a tungsten halide, a tantalum halide, or a vanadium halide, or a combination of two or more thereof.

### Claim 11 (depends on 8)

The method of claim 8, wherein the metal silicide film contains titanium silicide, molybdenum silicide, tungsten silicide, tantalum silicide, or vanadium silicide, or a combination of two or more thereof.

### Claim 12 (depends on 8)

The method of claim 8, wherein the metal silicide film is conformally deposited over the surfaces of a deep trench formed in the substrate.

### Claim 13 (depends on 12)

The method of claim 12, wherein the deep trench has a width between about 50 nm and 100 nm, a depth between about 2000 nm and 5000 nm, and an aspect ratio between about 40:1 and about 100:1.

### Claim 14 (depends on 8)

The method of claim 8, wherein the metal precursor comprises a titanium halide, the reducing gas comprises H2, and the metal silicide layer comprises titanium silicide.

### Claim 15 (depends on 14)

The method of claim 14, wherein the first and second substrate temperatures are below about 450° C.

### Claim 16

A method of forming a metal silicide film on a substrate, comprising:
a) providing a substrate in a process chamber;
b) thermally exposing the substrate at a first substrate temperature to a deposition gas containing a metal precursor in the absence of a plasma, wherein the thermal exposure forms a conformal metal-containing layer on the substrate in a self-limiting process;
c) modifying the metal-containing layer at a second substrate temperature by an exposure to a plasma consisting of only a noble gas; and
d) exposing the modified metal-containing layer at a second substrate temperature to a reducing gas in the absence of a plasma, wherein the b)-d) are sequentially and alternatively performed at least once to form the metal silicide film.

### Claim 17 (depends on 16)

The method of claim 16, wherein the deposition gas comprises a titanium halide, a molybdenum halide, a tungsten halide, a tantalum halide, or a vanadium halide, or a combination of two or more thereof.

### Claim 18 (depends on 16)

The method of claim 16, wherein the metal silicide film contains titanium silicide, molybdenum silicide, tungsten silicide, tantalum silicide, or vanadium silicide, or a combination of two or more thereof.

### Claim 19 (depends on 16)

The method of claim 16, wherein the metal silicide film is conformally deposited over the surfaces of a deep trench formed in the substrate.

### Claim 20 (depends on 16)

The method of claim 16, wherein the deep trench has a width between about 50 nm and 100 nm, a depth between about 2000 nm and 5000 nm, and an aspect ratio between about 40:1 and about 100:1.

### Claim 21 (depends on 16)

The method of claim 16, wherein the metal precursor comprises a titanium halide, the reducing gas comprises H2, and the metal silicide layer comprises titanium silicide.

### Claim 22 (depends on 21)

The method of claim 21, wherein the first and second substrate temperatures are between about 450° C. and about 650° C.