Patent US3615938A successfully refreshed from Google Patents.
US3615938A
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Method for diffusion of acceptor impurities into semiconductors
Assignee: Westinghouse Electric Corp
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Filing: 1969-01-28
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Granted: 1971-10-26
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Expires: 1989-01-28
Abstract
Abstract A diffusion process for acceptor impurities is provided wherein, after deposition of the impurity on the semiconductor surface, the surface is covered by a deposited insulating layer to avoid out diffusion during the heating to drive in the deposited impurity.
Inventors
- 👤 Joseph C Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:02
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D84/00; H10D84/40; H10D84/401; H10D84/403; H10D84/80; H10D84/82; H10D84/83; H10D84/85; H10D84/858; H10D99/00; H10P32/00; H10P32/10; H10P32/14; H10P32/1404; H10P32/17; H10P32/171; Y; Y10; Y10S; Y10S148/00; Y10S148/106; Y10S438/00; Y10S438/965
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
10 words
forming at least a first window within said first layer;
Claim 2
Dependent Claim
13 words
depositing boron on said surface within the area defined by said first window;
Claim 3
Dependent Claim
33 words
depositing on the surface of saiD first layer and on said surface within the area defined by said first window a second layer of an oxide of silicon formed by a vapor reaction;
Claim 4
Dependent Claim
20 words
forming a second window within said second layer where said second layer is at least partially within said first window;
Claim 5
Dependent Claim
71 words
heating to redistribute the deposited boron in an atmosphere that oxidizes said surface whereby said boron forms a P-type region that penetrates more deeply and has a higher surface concentration under said second layer than under said second window within said second layer, and thereafter selectively diffusing a pair of spaced N-type regions in said P-type region, thereby defining a field effect channel region therebetween of material under said second window.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |