Patent US4331710A successfully refreshed from Google Patents.
US4331710A
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US
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Method of forming an insulation film on semiconductor device surface
Assignee: Fujitsu Ltd
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Filing: 1979-02-19
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Granted: 1982-05-25
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Expires: 1999-02-19
Abstract
Abstract In a method of forming an insulating film on the surface of a silicon substrate, a silicon nitride film is formed on such surface by direct thermal nitridation. The nitridation is initially in an ambient gas of nitrogen whereby a comparatively thick silicon nitride film is formed. The ambient gas is then changed to ammonia or a mixture of an inert gas and ammonia to densify the silicon nitride film. The resultant film is useful as an insulating film in semiconductor devices, masks for impurity diffusion and selective oxidation in the manufacture thereof.
Inventors
- 👤 Takao Nozaki
- 👤 Takashi Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:19
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6322; H10P14/6316; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/66; H10P14/662; H10P14/69; H10P14/694; H10P14/6943; H10P14/69433; Y; Y10; Y10S; Y10S148/00; Y10S148/112; Y10S148/114
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
76 words
A method of forming a silicon nitride film on the surface of a silicon substrate, said method comprising the steps of forming a silicon nitride film on the surface of a substrate by direct thermal nitridation in an ambient gas of nitrogen; and changing the ambient gas to a reaction gas of one of ammonia and a mixture of an inert gas and ammonia to further the direct thermal nitridation to densify the silicon nitride film.
Claim 2
Independent Claim
76 words
A method of forming a silicon nitride film on the surface of a silicon substrate, said method comprising the steps of forming a silicon nitride film on the surface of a substrate by direct thermal nitridation in an ambient gas of nitrogen; and changing the ambient gas to a reaction gas of one of ammonia and a mixture of an inert gas and ammonia to further the direct thermal nitridation to densify the silicon nitride film.
References Cited (Backward Citations)
US3520722A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |