US3788913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon nitride on silicon oxide coatings for semiconductor devices
Assignee: Hitachi Ltd
•
Filing: 1970-08-20
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Granted: 1974-01-29
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Expires: 1990-08-20
Abstract
Abstract D R A W I N G A METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE WHEREIN A SILICON NITRIDE FILM COVERS THE EXPOSED SURFACES OF AN OXIDE FILM AND THE EXPOSED MAJOR SURFACE OF A SEMICONDUCTOR BODY, AND WHEREIN HOLES ARE FORMED BY CHEMICAL ETCHING ONLY IN THE PORTION OF SAID SILICON NITRIDE FILM DIRECTLY CONTACTING SAID MAJOR SURFACE, THEREBY OBTAINING PRECISE ETCHING OF THE INSULATING COVERING.
Inventors
- 👤 M Ono
- 👤 T Momoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:34
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/40; H10P; H10P95/00; H10W74/43; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 0
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |