US4010064A
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Controlling the oxygen content of Czochralski process of silicon crystals by sandblasting silica vessel
Assignee: International Business Machines Corp
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Filing: 1975-05-27
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Granted: 1977-03-01
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Expires: 1995-05-27
Abstract
Abstract The oxygen content of silicon crystals, which are drawn from a silicon melt contained in a silica vessel according to the Czochralski process, is controlled by changing the surface characteristics of the portion of the silica vessel which is in contact with the melt so as to provide an increased oxygen concentration in the melt during the crystal drawing process.
Inventors
- 👤 William John Patrick
- 👤 Salvatore James Scilla
- 👤 Wolfgang Alfred Westdorp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:43
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C30B15/00; C30B15/10; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1032
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
88 words
A process for increasing the oxygen content and reducing the oxygen concentration gradient through the length of a silicon crystal, which is drawn from a silicon melt contained in a silica vessel according to the Czochralski process, comprising: treating said vessel to change the characteristics of the silica surface which is in contact with said melt by roughening said surface by sandblasting until said surface becomes opaque, so as to provide a more uniform dissolution rate of said silica surface by said melt during the crystal growing process.
Claim 2
Dependent Claim
88 words
A process for increasing the oxygen content and reducing the oxygen concentration gradient through the length of a silicon crystal, which is drawn from a silicon melt contained in a silica vessel according to the Czochralski process, comprising: treating said vessel to change the characteristics of the silica surface which is in contact with said melt by roughening said surface by sandblasting until said surface becomes opaque, so as to provide a more uniform dissolution rate of said silica surface by said melt during the crystal growing process.
Claim 3
Dependent Claim
101 words
A process for increasing and tailoring through the length of a silicon crystal the oxygen content and producing a decreased oxygen content gradient through the length of the silicon crystal, which is drawn from a silicon melt contained in a silica vessel according to the Czochralski process, comprising: treating a portion of from about 50% to the entire silica surface which is in contact with the melt by roughening said portion of said surface by sandblasting until said portion become opaque, so as to provide a more uniform dissolution rate of said portion by said melt during the crystal growing process.
Claim 4
Dependent Claim
101 words
A process for increasing and tailoring through the length of a silicon crystal the oxygen content and producing a decreased oxygen content gradient through the length of the silicon crystal, which is drawn from a silicon melt contained in a silica vessel according to the Czochralski process, comprising: treating a portion of from about 50% to the entire silica surface which is in contact with the melt by roughening said portion of said surface by sandblasting until said portion become opaque, so as to provide a more uniform dissolution rate of said portion by said melt during the crystal growing process.
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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |