US3791948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preferential etching in g a p
Assignee: AT&T Inc
•
Filing: 1971-11-01
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Granted: 1974-02-12
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Expires: 1991-11-01
Abstract
Abstract THE SPECIFICATION DESCRIBES A PROCESS FOR ETCHING N-TYPE GALLIUM PHOSPHIDE IN PREFERENCE TO P-TYPE. THE N-TYPE MATERIAL IS ANODIZED IN A SOLUTION OF SODIUM OR POTASSIUM HYPOCHLORITE AND HYDROCHLORIC ACID.
Inventors
- 👤 T Mcgahan
- 👤 R Dixon
- 👤 W Hackett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:26
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; C; C25; C25F; C25F3/00; C25F3/02; C25F3/12; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/924
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |