US5211801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing single-crystal silicon carbide
Assignee: Infineon Technologies AG
•
Filing: 1991-07-15
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Granted: 1993-05-18
•
Expires: 2011-07-15
Abstract
Abstract Single crystals of silicon carbide (SiC) can be manufactured by subliming and partially decomposing a base material of crystalline silicon carbide powder and by growing the single crystals from seed crystals. According to the present invention, an excess of silicon is added to the silicon carbide base material. Using this technique, high purity, single-crystal silicon carbide is obtained.
Inventors
- 👤 Rene Stein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:53
CPC Classifications
C; C30; C30B; C30B23/00; C30B29/00; C30B29/10; C30B29/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
81 words
A method for the growth of single-crystal silicon carbide in a reaction vessel having a protective atmosphere and a small temperature gradient in the direction of growth, comprising: adding excess silicon to a crystalline silicon carbide powder; subliming and partially decomposing the crystalline silicon carbide powder; and growing, on a seed crystal, single crystals of silicon carbide from the sublimed and partially decomposed crystalline silicon carbide powder; wherein said excess silicon is in an amount of from about 0.1% to 5%.
Claim 2
Independent Claim
81 words
A method for the growth of single-crystal silicon carbide in a reaction vessel having a protective atmosphere and a small temperature gradient in the direction of growth, comprising: adding excess silicon to a crystalline silicon carbide powder; subliming and partially decomposing the crystalline silicon carbide powder; and growing, on a seed crystal, single crystals of silicon carbide from the sublimed and partially decomposed crystalline silicon carbide powder; wherein said excess silicon is in an amount of from about 0.1% to 5%.
Claim 3
Dependent Claim
25 words
The method for the manufacture of single-crystal silicon carbide as recited in claim 1, wherein the crystalline silicon carbide powder is manufactured from highly-purified silicon.
Claim 4
Dependent Claim
39 words
The method for the manufacture of single-crystal silicon carbide as recited in claim 1, wherein the crystalline silicon carbide powder is industrial silicon carbide and the method further comprises purifying the industrial silicon carbide before adding the excess silicon.
Claim 5
Dependent Claim
25 words
The method for the manufacture of single-crystal silicon carbide as recited in claim 1, wherein the excess silicon is added in a finely dispersed form.
Claim 6
Dependent Claim
28 words
The method for the manufacture of single-crystal silicon carbide as recited in claim 1 wherein the crystalline silicon carbide powder has a molar Si:C ratio greater than 1.
Claim 7
Dependent Claim
28 words
The method for the manufacture of single-crystal silicon carbide as recited in claim 1, wherein said excess silicon is in an amount of from about 1% to 2%.
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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) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |