US3862852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of obtaining high-quality thick films of polycrystalline silicone from dielectric isolation
Assignee: Fairchild Semiconductor Corp
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Filing: 1973-06-01
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Granted: 1975-01-28
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Expires: 1993-06-01
Abstract
Abstract A polycrystalline silicon film is formed in an environment with minimum oxygen, thereby to reduce or substantially eliminate bowing of the wafer on which the polycrystalline silicon film is formed.
Inventors
- 👤 Theodore I Kamins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:58
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/24; Y; Y10; Y10S; Y10S148/00; Y10S148/085; Y10S148/097; Y10S148/122
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
18 words
The method of claim 1 wherein said deposition of polycrystalline silicon takes place by the decomposition of dichlorosilane.
Claim 2
Dependent Claim
44 words
The method of claim 2 wherein said dichlorosilane flows at a rate of 1.3 liters per minute, said hydrogen flows at a rate of 67 liters per minute and the polycrystalline silicon is formed on a substrate held at a temperature of 1,100* C.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the ratio of oxygen to hydrogen is held beneath ten parts of oxygen to each million parts of hydrogen.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |