US3552071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for polishing crystalline silicon
Assignee: Tizon Chemical Corp
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Filing: 1967-10-30
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Granted: 1971-01-05
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Expires: 1987-10-30
Abstract
Abstract A PROCESS IS PROVIDED FOR POLISHING CRYSTALLINE SILICON EMPLOYING AN AQUEOUS POLISHING SLURRY CONTAINING FROM ABOUT 0.25 TO ABOUT 50% OF AN ALKALINE EARTH METAL HYDROXIDE OF WHICH FROM ABOUT 0.05 TO ABOUT 50% IS UNDISSOLVED AND HAVING A PH OF AT LEAST 9. EXAMPLES OF SUCH POLISHING SLURRIES INCLUDE AQUEOUS SLURRIES OF CALCIUM HYDROXIDE AND STRONTIUM HYDROXIDE. THE AQUEOUS SLURRY OF THE ALKALINE EARTH METAL HYDROXIDE CAN BE FORMED BY MIXING THE ALKALINE EARTH METAL HYDROXIDE AND WATER, OF BY FORMING THE HYDROXIDE IS SITU IN WATER, E.G. BY REACTING AN ALKALINE EATRTH METAL COMPOUND WHICH REACTS IN AN AQUEOUS SYSTEM, WITH A BASE TO PRODUCE THE ALKALINE EARTH METAL HYDROXIDE.
Inventors
- 👤 Richard P Albanese
- 👤 Glenn H Mcintyre Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:28
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C09K3/1454; H; H10; H10P; H10P52/00; H10P52/40; H10P52/402
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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |