Patent US5477808A successfully refreshed from Google Patents.
US5477808A
Expired / Lapsed
US
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Process for reducing the oxygen incorporation into a single crystal of silicon
Assignee: Siltronic AG
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Filing: 1994-02-28
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Granted: 1995-12-26
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Expires: 2014-02-28
Abstract
Abstract A process and an apparatus reduces the oxygen incorporation into a single crystal of silicon which is drawn by the Czochralski method. If a molding is immersed at least temporarily in the melt between the single crystal and the crucible wall during drawing of the single crystal, the oxygen content of the single crystal is reduced compared with the oxygen content of a single crystal which has been drawn without the use of the molding.
Inventors
- 👤 Hans Oelkrug
- 👤 Franz Segieth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:18
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C30B15/00; H; H10; H10P; H10P14/00; H10P14/20; H10P14/34; H10P14/3451; H10P14/3452; H10P14/3458; H10P14/60; H10P14/69; H10P14/6903
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
78 words
A process for reducing the oxygen incorporation into a single crystal of silicon, said single crystal being drawn from a melt, which is present in a quartz-lined crucible, comprising immersing a molding in the melt between the single crystal and an inner wall of the crucible and keeping the molding stationary during drawing of the single crystal; and moving the molding and the melt relative to one another, while the molding offers a high resistance to the melt.
Claim 2
Dependent Claim
78 words
A process for reducing the oxygen incorporation into a single crystal of silicon, said single crystal being drawn from a melt, which is present in a quartz-lined crucible, comprising immersing a molding in the melt between the single crystal and an inner wall of the crucible and keeping the molding stationary during drawing of the single crystal; and moving the molding and the melt relative to one another, while the molding offers a high resistance to the melt.
Claim 3
Dependent Claim
15 words
The process as claimed in claim 1, wherein the depth of immersion is 10-20 mm.
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) | 1998-12-25 | 1999-06-26 | 1999-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-25 | 2003-06-26 | 2003-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-25 | 2007-06-26 | 2007-12-26 | $7700.00 | Window Closed / Lapsed |