US3560280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of selective removal of oxide coatings in the manufacture of semiconductor devices
Assignee: Hitachi Ltd
•
Filing: 1969-11-21
•
Granted: 1971-02-02
•
Expires: 1989-11-21
Abstract
Abstract AN OXIDE FILM FORMED ON A SEMICONDUCTOR SUBSTRATE IS SELECTIVELY ETCHED BY DIFFUSING A METAL SUCH AS ALUMINUM OR CHROMIUM INTO THE OXIDE FILM PRIOR TO ETCHING THE FILM. THE DIFFUSED METAL HARDENS THE OXIDE FILM AND PREVENTS EXCESSIVE SIDE ETCHING. OTHER METALS SUCH AS, FOR EXAMPLE, ZIRCONIUM ZINC, TITANIUM, MOLYBDUNUM, RHODIUM, GOLD, NIOBIUM, CALCIUM, MAGNESIUM AND BARIUM AND THE OXIDES OF THESE METALS MAY BE EMPLOYED.
Inventors
- 👤 Sumio Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:27
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/73; H10P50/20; H10P50/28; H10P50/282; H10P50/283; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/051; Y10S438/00; Y10S438/914; Y10S438/924
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) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |