US3677848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and material for etching semiconductor bodies
Assignee: RCA Corp
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Filing: 1970-07-15
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Granted: 1972-07-18
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Expires: 1990-07-15
Abstract
Abstract AN ETCHANT FOR UNIFORMLY ETCHING BODIES OF SILICON OR GERMANIUM WHICH PROVIDES AN ETCHED SURFACE WHICH IS FREE FROM PITS AND PEAKS. THE BODY IS ETCHED BY IMMERSING A SURFACE OF THE BODY IN A MIXTURE OF HYDROFLUORIC ACID, NITRIC ACID, ACETIC ACID AND EITHER SODIUM CHLORITE OR SODIUM NITRITE AND BUBBLING A GAS INTO THE ETCHANT SO THAT AT LEAST SOME OF THE GAS BUBBLES IMPINGE ON THE SURFACE OF THE BODY.
Inventors
- 👤 Arthur Irwin Stoller
- 👤 Stephen Thomas Opresko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:25
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; C; C09; C09K; C09K13/00; C09K13/04; C09K13/08; H10P50/00; H10P50/60; H10P50/64; H10P50/642
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |