US3629670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical contact to silicon carbide
Assignee: General Electric Co
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Filing: 1970-09-23
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Granted: 1971-12-21
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Expires: 1990-09-23
Abstract
Abstract Yttrium metal provides a low-resistance electrical contact to a silicon carbide wafer, useful in the manufacture of solid-state lamps. A preferred method comprises the steps of placing a small piece of yttrium on a silicon carbide wafer, and heating to cause fusion to occur.
Inventors
- 👤 Ronald J Perusek
- 👤 Ralph M Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:20
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/871; H10P; H10P32/00; H10P32/10; H10P32/17; H10P32/171; H10P32/172; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0115; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
20 words
A contact as claimed in claim 1, in which said yttrium metal is in fusion contact with said silicon carbide.
Claim 2
Dependent Claim
44 words
A contact as claimed in claim 1, in which said silicon carbide is in the form of a wafer having a PN-junction at the interface of a P-type region and an N-type region, said contact being positioned at the surface of said N-type region.
Claim 3
Independent Claim
38 words
A method of making an electrical contact to silicon carbide, comprising the steps of placing a piece of yttrium metal on said silicon carbide, and heating the combination to cause fusion of the yttrium with the silicon carbide.
Claim 4
Dependent Claim
41 words
A method as claimed in claim 4, in which said heating comprises bringing the combination to a temperature of about 2, 100* C. until fusion commences, reducing the temperature to about 1,650* C. for a few seconds, and allowing to cool.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 5, in which said heating is carried out in an atmosphere of argon.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 5, in which said heating is carried out in an atmosphere of argon containing nitrogen.
Claim 7
Dependent Claim
46 words
A method as claimed in claim 4, in which said silicon carbide is in the form of a wafer having a PN-junction at the interface of a P-type region and an N-type region, said piece of yttrium being placed on the surface of said N-type region.
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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |