US3709749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of etching insulating films
Assignee: Fujitsu Ltd
•
Filing: 1970-11-24
•
Granted: 1973-01-09
•
Expires: 1990-11-24
Abstract
Abstract A METHOD OF ETCHING INSULATING FILM WHEREIN A SUBSTRATE HAVING A SILICON NITRIDE FILM OR A SILICON OXIDE FILM IS DIPPED IN HIGH TEMPERATURE WATER OF ABOVE 100* C. D R A W I N G
Inventors
- 👤 J Sato
- 👤 T Tanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:10
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |