US3679501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of polishing gallium phosphide
Assignee: International Business Machines Corp
•
Filing: 1970-04-13
•
Granted: 1972-07-25
•
Expires: 1990-04-13
Abstract
Abstract A METHOD OF POLISHING GALLIUM PHOSPHIDE USED IN THE MANUFACTURE OF SEMICONDUCTIVE DEVICES. A GALLIUM PHOSPHIDE WAFER IS IMMERSED IN A SOLUTION CONSISTING OF FROM ABOUT 15 TO 20 PARTS BY VOLUME OF CONCENTRATED HYDROFLUORIC ACID AND FROM ABOUT 3 TO ABOUT 0.5 PARTS OF CONCENTRATED NITRIC ACID. TREATMENT BY THE HF-HNO3 SOLUTION OF THIS INVENTION LEAVES THE WAFER SUBSTANTIALLY PIT FREE WITH A MIRROR-LIKE SURFACE.
Inventors
- 👤 Richard J Chicotka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:13
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |