US5298458A
Expired / Lapsed
US
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Method of forming tungsten film
Assignee: Fujitsu Semiconductor Ltd
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Filing: 1992-10-28
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Granted: 1994-03-29
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Expires: 2012-10-28
Abstract
Abstract A tungsten film is deposited on a substrate by a CVD process using a source gas comprising WF 6 , a silane group compound such as SiH 4 , Si 2 H 6 , Si 3 H 8 or Si 4 H 10 , and hydrogen fluoride or fluorine, at a lower temperature than in the prior art. The resultant tungsten film has low sheet resistance and good step coverage. The tungsten film may be selectively deposited.
Inventors
- 👤 Fumitake Mieno
- 👤 Yuji Furumura
- 👤 Toshihiko Ono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:20
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/06; C23C16/08; H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10W; H10W20/00; H10W20/01; H10W20/031
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
50 words
A method of forming a tungsten film on a substrate by a chemical vapor deposition (CVD) process using a source gas, wherein a gaseous mixture comprising tungsten hexafluoride gas, a gas whose molecules consist of silicon and hydrogen, and hydrogen fluoride or fluorine gas is used as the source gas.
Claim 2
Independent Claim
50 words
A method of forming a tungsten film on a substrate by a chemical vapor deposition (CVD) process using a source gas, wherein a gaseous mixture comprising tungsten hexafluoride gas, a gas whose molecules consist of silicon and hydrogen, and hydrogen fluoride or fluorine gas is used as the source gas.
Claim 3
Dependent Claim
43 words
The method of claim 1, wherein the gas whose molecules consist of silicon and hydrogen is selected from the group consisting of SiH 4 , Si 2 H 6 , Si 3 H 8 , Si 4 H 10 , or mixtures thereof.
Claim 4
Dependent Claim
18 words
The method of claim 1, wherein the tungsten film is deposited on the whole surface of the substrate.
Claim 5
Dependent Claim
22 words
The method of claim 1, wherein the tungsten film is deposited on the portion or portions of the surface of the substrate.
Claim 6
Dependent Claim
19 words
The method of claim 1, wherein the tungsten film is deposited at a temperature of 300° to 400° C.
Claim 7
Dependent Claim
19 words
The method of claim 3, wherein the tungsten film is deposited at a pressure of 50 to 100 Torr.
Claim 8
Dependent Claim
19 words
The method of claim 4, wherein the tungsten film is deposited at a pressure of 0.01 to 1.0 Torr.
Claim 9
Dependent Claim
21 words
The method of claim 4, wherein the molar ratio of silicon to fluorine in the source gas is 1:4 or more.
References Cited (Backward Citations)
US4902645A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-28 | 1997-09-27 | 1998-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-28 | 2001-09-27 | 2002-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-28 | 2005-09-27 | 2006-03-29 | $7700.00 | Window Closed / Lapsed |