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US4735920A
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Method for structuring silicon carbide
Assignee: Siemens AG
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Filing: 1987-02-04
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Granted: 1988-04-05
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Expires: 2007-02-04
Abstract
Abstract A method for structuring silicon carbide by photolithography and plasma etching wherein a substrate of silicon carbide is covered on a flat side with a structured silicon layer, and the plasma etching is then carried out with a gaseous mixture of a halogenated hydrocarbon and oxygen, the oxygen being present in an amount of at least 40% and preferably 70 to 95% by volume.
Inventors
- 👤 Dietrich Stephani
- 👤 Peter Lanig
- 👤 Guenther Ziegler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:08
CPC Classifications
H; H10; H10P; H10P50/00; Y; Y10; Y10S; Y10S148/00; Y10S148/148; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
85 words
A method of structuring silicon carbide which comprises: providing a planar substrate of silicon carbide, covering one flat surface of said substrate with a layer of silicon, etching said layer of silicon to provide a structured silicon mask, and plasma etching the underlying substrate through said structured silicon mask employing a gaseous mixture of a halogenated hydrocarbon and oxygen, said oxygen constituting at least 40% by volume of said mixture whereby said substrate of silicon carbide is etched more rapidly than said structured silicon mask.
Claim 2
Independent Claim
85 words
A method of structuring silicon carbide which comprises: providing a planar substrate of silicon carbide, covering one flat surface of said substrate with a layer of silicon, etching said layer of silicon to provide a structured silicon mask, and plasma etching the underlying substrate through said structured silicon mask employing a gaseous mixture of a halogenated hydrocarbon and oxygen, said oxygen constituting at least 40% by volume of said mixture whereby said substrate of silicon carbide is etched more rapidly than said structured silicon mask.
Claim 3
Dependent Claim
17 words
A method according to claim 1 wherein said mixture contains from 70 to 95% by volume oxygen.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein said halogenated hydrocarbon is carbon tetrafluoride.
Claim 5
Dependent Claim
13 words
A method according to claim 2 wherein said halogenated hydrocarbon is carbon tetrafluoride.
Claim 6
Dependent Claim
15 words
A method according to claim 1 wherein said silicon carbide is the hexagonal modification 6H-SiC
Claim 7
Independent Claim
85 words
A method of structuring a silicon carbide substrate which comprises: applying a layer of silicon over said substrate, applying a resist mask over said substrate, plasma etching said substrate through said mask using a mixture of carbon tetrafluoride and oxygen containing not more than 30% by volume oxygen to reproduce the pattern of said resist mask in a silcon mask and, thereafter plasma etching the substrate through said silicon mask with a mixture of carbon tetrafluoride and oxygen containing at least 40% by volume oxygen.
Claim 8
Independent Claim
85 words
A method of structuring a silicon carbide substrate which comprises: applying a layer of silicon over said substrate, applying a resist mask over said substrate, plasma etching said substrate through said mask using a mixture of carbon tetrafluoride and oxygen containing not more than 30% by volume oxygen to reproduce the pattern of said resist mask in a silcon mask and, thereafter plasma etching the substrate through said silicon mask with a mixture of carbon tetrafluoride and oxygen containing at least 40% by volume oxygen.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |