US4981723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical vapor deposition of tungsten silicide using silicon sub-fluorides
Assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Filing: 1988-10-17
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Granted: 1991-01-01
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Expires: 2008-10-17
Abstract
Abstract A process for depositing tungsten silicide films on a silicon substrate by chemical vapor deposition, comprises the steps of producing a silicon sub-fluoride by passing SiF 4 over pieces of silicon heated in a tubular oven about 1200°-1500° K., mixing gaseous WF 6 with the silicon sub-fluoride, and then immediately depositing the tungsten silicide films on said silicon substrate.
Inventors
- 👤 Ikuo Hirase
- 👤 Denis Rufin
- 👤 Michael Schack
- 👤 Tooru Sumiya
- 👤 Masamichi Matsuura
- 👤 Sadayuki Urishima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:26
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/30; C23C16/42; H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10P; H10P14/00; H10P14/40; H10P14/412; H10P14/414
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
61 words
A process for depositing tungsten silicides on a silicon substrate by vapor phase chemical deposition, comprising the steps of: producing a silicon sub-fluoride by passing SiF 4 over pieces of silicon heated in a tubular oven at about 1200°-1500° K.; mixing in gaseous form WF 6 with said silicon sub-fluoride, and then immediately depositing said tungsten silicides on said silicon substrate.
Claim 2
Dependent Claim
61 words
A process for depositing tungsten silicides on a silicon substrate by vapor phase chemical deposition, comprising the steps of: producing a silicon sub-fluoride by passing SiF 4 over pieces of silicon heated in a tubular oven at about 1200°-1500° K.; mixing in gaseous form WF 6 with said silicon sub-fluoride, and then immediately depositing said tungsten silicides on said silicon substrate.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein said silicon substrate is heated in the deposition step through a quartz plate underlying the silicon substrate.
Claim 4
Dependent Claim
21 words
The process of claim 1, wherein said deposition is carried out in a reactor with cold walls maintained under partial vacuum.
Claim 5
Dependent Claim
18 words
The process of claim 1, wherein said WF 6 and silicon sub-fluoride are mixed with a carrier gas.
Claim 6
Dependent Claim
22 words
The process of claim 4, wherein said carrier gas is selected from the group consisting of Ar, He, and H 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-31 | 1994-07-02 | 1995-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-31 | 1998-07-02 | 1999-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-31 | 2002-07-02 | 2003-01-01 | $7700.00 | Window Closed / Lapsed |