US3767484A
Expired / Lapsed
US
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Method of manufacturing semiconductor devices
Assignee: Fujitsu Ltd
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Filing: 1971-10-06
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Granted: 1973-10-23
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Expires: 1991-10-06
Abstract
Abstract A method of manufacturing a semiconductor device which comprises: forming an oxide film containing an impurity on one surface of a semiconductor substrate; forming an oxidation preventing film on the portion of the oxide film above the region of said substrate into which the impurity is to be diffused; and heating the substrate in an oxidizing atmosphere containing steam to diffuse the impurity into only the region.
Inventors
- 👤 S Takagi
- 👤 M Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:37
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/40; H10D; H10D99/00; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/117; Y10S148/118; Y10S252/00; Y10S252/95; Y10S252/951
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
77 words
A method of manufacturing an insulated gate field effect transistor, comprising the steps of: a. forming an oxide film containing boron or phosphorous on one surface of a silicon substrate; b. forming silicon nitride films on the portion of said oxide film above the regions of said substrate in which a source and a drain are to be formed; and c. heating said substrate in an oxidizing atmosphere containing steam to form the source and the drain.
Claim 2
Dependent Claim
49 words
The method of claim 2, having the additional steps of removing said oxide film between the source and drain by the use of said silicon nitride films as the mask for chemical etching and forming a gate insulation film on the exposed silicon surface between the source and drain.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |