US4837376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for refining silicon and silicon purified thereby
Assignee: SolarWorld Industries Sachsen GmbH
•
Filing: 1987-10-05
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Granted: 1989-06-06
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Expires: 2007-10-05
Abstract
Abstract Highly pure silicon is produced by refining impure silicon to remove deleterious impurities by contacting a melt of the impure silicon with a reacitve gas which comprises a gaseous halogen compound mixed with steam, hydrogen or a stem/hydrogen mixture.
Inventors
- 👤 Ingo Schwirtlich
- 👤 Horst Lange
- 👤 Werner Kannchen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:15
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/02; C01B33/037
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
62 words
A process for refining silicon to remove impurities which comprises contacting a silicon melt with a reactive gas which comprises a gaseous halogen compound mixed with steam, hydrogen, or a steam/hydrogen mixture wherein the halogen compound is at least one halogen silane of the formula Si n X 2n+2 , wherein n is 1 to 4 and X represents halogen and/or hydrogen.
Claim 2
Dependent Claim
62 words
A process for refining silicon to remove impurities which comprises contacting a silicon melt with a reactive gas which comprises a gaseous halogen compound mixed with steam, hydrogen, or a steam/hydrogen mixture wherein the halogen compound is at least one halogen silane of the formula Si n X 2n+2 , wherein n is 1 to 4 and X represents halogen and/or hydrogen.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the halogen compound is silicon tetrachloride.
Claim 4
Dependent Claim
19 words
A process according to claim 1 wherein the reactive gas is a mixture of silicon tetrachloride, steam and hydrogen.
Claim 5
Dependent Claim
16 words
A process according to claim 1 wherein an inert gas is added to the reactive gas.
Claim 6
Dependent Claim
12 words
A process according to claim 4 wherein the inert gas is argon.
Claim 7
Dependent Claim
25 words
A process according to claim 1 wherein the silicon melt is subsequently degasses by a vacuum treatment at pressures of 10 -1 mbar or less.
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US3442622A
Cited
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Cited
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Cited
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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) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |