US5358603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the removal of a silicon coating from a surface
Assignee: Albemarle Corp
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Filing: 1992-10-06
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Granted: 1994-10-25
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Expires: 2012-10-06
Abstract
Abstract This invention relates to a process for etching a silicon coat on the inside wall of a tube. The tube may be a product discharge tube associated with a fluidized bed reactor used in the thermal production of silicon from a silicon containing compound, e.g., silane. The process features: a) heating the silicon coat to a temperature within the range of from about 500° to about 750° C., such heating occurring principally with radiant heat from a heating means inserted within the interior of the tube; and (b) contacting the heated silicon coat with a mineral acid which etches the heated silicon coat.
Inventors
- 👤 Jameel Ibrahim
- 👤 Richard J. Fendley
- 👤 Troy E. DeSoto
- 👤 Jerry G. Hitchens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:15
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/4401; C23C16/4407; B; B01; B01J; B01J8/00; B01J8/18; B01J8/1872
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
103 words
A process for etching a silicon coating from a product withdrawal tube, which tube is used to discharge polysilicon granules from a fluidized bed reactor, the process comprising: (a) shutting down the reactor; (b) inserting a heating means into the interior of the withdrawal tube while the withdrawal tube is still associated with the reactor; (c) using the heating means to heat the silicon coat about the interior wall of the withdrawal tube whereby the coat is heated to a temperature within the range of from about 500° C. to about 750° C.; and (d) etching the heated coat with a mineral acid.
Claim 2
Dependent Claim
103 words
A process for etching a silicon coating from a product withdrawal tube, which tube is used to discharge polysilicon granules from a fluidized bed reactor, the process comprising: (a) shutting down the reactor; (b) inserting a heating means into the interior of the withdrawal tube while the withdrawal tube is still associated with the reactor; (c) using the heating means to heat the silicon coat about the interior wall of the withdrawal tube whereby the coat is heated to a temperature within the range of from about 500° C. to about 750° C.; and (d) etching the heated coat with a mineral acid.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein the heating of the silicon coating is effected by inserting a tubular, elongated heater within the interior of the product withdrawal tube.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the mineral acid is hydrochloric acid.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein the heating of the silicon coating is effected by inserting a tubular, elongated heater within the interior of the product withdrawal tube.
References Cited (Backward Citations)
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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) | 1997-10-24 | 1998-04-25 | 1998-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-24 | 2002-04-25 | 2002-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-24 | 2006-04-25 | 2006-10-25 | $7700.00 | Window Closed / Lapsed |