US2998362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of selectively electrolytically etching semiconductor silicon materials
Assignee: Transitron Electronic Corp
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Filing: 1958-10-16
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Granted: 1961-08-29
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Expires: 1978-10-16
Abstract
No abstract record available.
Inventors
- 👤 Roderic E Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:22
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/61; H10P50/613
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A METHOD OF ETCHING ONE LAYER ONLY OF A PIECE OF SEMICONDUCTOR SILICON MATERIALS WHEREIN SAID PIECE HAS A PLURALITY OF LAYERS OF DONOR AND ACCEPTOR IMPURITIES COMPRISING SUBMERGING SAID PIECE IN A SOLUTION CONSISTING ESSENTIALLY OF HYDROFLUORIC ACID, WATER AND AN ORGANIC ACID, WHEREIN 400 CC. OF SAID SOLUTION HAS BETWEEN SUBSTANTIALLY 60 AND 180 CC. HYDROFLUORIC ACID AND 20 TO 40 GRAMS OF ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF ACETIC ACID, CITRIC ACID, MANDELIC ACID, TATRARIC AND MALEIC, ACID, SECURING ONE END LAYER ONLY OF SAID PIECE TO A POSITIVE ELECTRODE SUBSTANTIALLY INSULATED FROM SAID
Claim 2
Independent Claim
99 words
A METHOD OF ETCHING ONE LAYER ONLY OF A PIECE OF SEMICONDUCTOR SILICON MATERIALS WHEREIN SAID PIECE HAS A PLURALITY OF LAYERS OF DONOR AND ACCEPTOR IMPURITIES COMPRISING SUBMERGING SAID PIECE IN A SOLUTION CONSISTING ESSENTIALLY OF HYDROFLUORIC ACID, WATER AND AN ORGANIC ACID, WHEREIN 400 CC. OF SAID SOLUTION HAS BETWEEN SUBSTANTIALLY 60 AND 180 CC. HYDROFLUORIC ACID AND 20 TO 40 GRAMS OF ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF ACETIC ACID, CITRIC ACID, MANDELIC ACID, TATRARIC AND MALEIC, ACID, SECURING ONE END LAYER ONLY OF SAID PIECE TO A POSITIVE ELECTRODE SUBSTANTIALLY INSULATED FROM SAID
References Cited (Backward Citations)
US2656496A
Cited
US2802159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-08-28 | 1965-02-27 | 1965-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-28 | 1969-02-27 | 1969-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-28 | 1973-02-27 | 1973-08-29 | $7700.00 | Window Closed / Lapsed |