Patent US4566460A successfully refreshed from Google Patents.
US2973253A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etching of semiconductor materials
Assignee: Texas Instruments Inc
•
Filing: 1957-12-09
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Granted: 1961-02-28
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Expires: 1977-12-09
Abstract
No abstract record available.
Inventors
- 👤 Richard R Stead
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:30
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; C; C09; C09K; C09K13/00; C09K13/04; C09K13/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
26 words
A METHOD OF ETCHING A SURFACE OF AN ELECTRICAL SEMICONDUCTOR WHICH COMPRISES ETCHING SAID SURFACE IN A SOLUTION OF NITRIC ACID, HYDROFLUORIC ACID, AND DI-SODIUM PHOSPHATE.
Claim 2
Independent Claim
26 words
A METHOD OF ETCHING A SURFACE OF AN ELECTRICAL SEMICONDUCTOR WHICH COMPRISES ETCHING SAID SURFACE IN A SOLUTION OF NITRIC ACID, HYDROFLUORIC ACID, AND DI-SODIUM PHOSPHATE.
References Cited (Backward Citations)
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US2619414A
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US2698780A
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US2893929A
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US2827367A
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US2847287A
Cited
US2871110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-02-28 | 1964-08-29 | 1965-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-28 | 1968-08-29 | 1969-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-28 | 1972-08-29 | 1973-02-28 | $7700.00 | Window Closed / Lapsed |