US3645686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of ultrapure semiconductor materials
Assignee: Dow Silicones Corp
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Filing: 1970-05-04
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Granted: 1972-02-29
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Expires: 1990-05-04
Abstract
Abstract A method of reducing the contamination of ultrapure materials, such as silicon, with impurities from carbon bodies used in the production of said material s which method comprises pretreating the carbon bodies with water vapor at high temperature whereby the impurities react with the water vapor and either diffuse to the surface of the carbon body and are removed or remain complexed within the carbon body.
Inventors
- 👤 Thomas N Tucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:08
CPC Classifications
H; H05; H05B; H05B7/00; H05B7/02; H05B7/06; H05B7/08; H05B7/085; C; C01; C01B; C01B32/00; C04; C04B; C04B35/00; C04B35/515; C04B35/52; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/145
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
In a process for the production of ultrapure semiconductor material wherein said semiconductor material is contaminated with impurities from carbon bodies, the method of reducing said contamination which comprises pretreating said carbon bodies with an atmosphere comprising a gas chosen from the group consisting of argon, hydrogen and nitrogen at a temperature of at least 800* C., said gas having been saturated with water at room temperature prior to subjecting the bodies to said atmosphere.
Claim 2
Dependent Claim
22 words
The method as defined in claim 2, wherein said atmosphere further includes up to 100 parts per million (atomic) of free oxygen.
Claim 3
Dependent Claim
23 words
The method as defined in claim 3, wherein said body is heated to about 1,100* C. while it is subjected to said atmosphere.
Claim 4
Dependent Claim
23 words
The method as defined in claim 2, wherein said body is heated to about 1,100* C. while it is subjected to said atmosphere.
Claim 5
Dependent Claim
13 words
The method as defined in claim 1, wherein said semiconductor material is silicon.
Claim 6
Dependent Claim
13 words
The method as defined in claim 1, wherein said carbon bodies are electrodes.
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |