US3874129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of haze-free semiconductor surfaces
Assignee: Siltronic AG
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Filing: 1973-09-25
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Granted: 1975-04-01
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Expires: 1993-09-25
Abstract
Abstract Producing semiconductors with exceptionally smooth haze-free surfaces in a multistage polishing process wherein polishing the semiconductor with a first and conventional polishing agent containing a silicon compound suspended in water is followed by polishing with a modified polishing agent comprising said first polishing agent in major proportion containing minor but effective additions of polyvinyl alcohol and a 3 to 5 carbon monohydroxy aliphatic alcohol.
Inventors
- 👤 Helmut Deckert
- 👤 Wolfgang Heinke
- 👤 Herbert Jacob
- 👤 Helmut Kirschner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:01
CPC Classifications
H; H10; H10P; H10P52/00; H10P52/40; H10P52/402
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
IN A PROCESS FOR THE PRODUCTION OF A SEMICONDUCTOR HAVING A HAZE-FREE POLISHED SURFACE BY POLISHING THE SEMICONDUCTOR WITH A POLISHING AGENT CONTAINING A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF QUARTS, A SLICIC ACID GELS OR SOLS, A SILICATE, A FLUOSILICATE, AND MIXTURES THEREOF, SAID SUBSTANCE HAVING A PARTICLE SIZE BETWEEN ABOUT 5 AND ABOUT 200 MU THE IMPROVEMENT WHICH COMPRISES FURTHER POLISHING THE SEMICONDUCTOR IN A SECOND POLISHING STEP WITH A MODIFIED POLISHING AGENT CONTAINING SAID FIRST POLISHING AGENT AND FROM ABOUT 0.01 PERCENT TO ABOUT 0.5 PERCENT BY WEIGHT OF POLYVINYL ALCOHOL CALCULATED ON THE WEIGHT OF SAID FIRST POLISHING AGENT, AND FROM ABOUT 1 PERCENT TO ABOUT 10 PERCENT BY VOLUME OF A SATURATED MONOHYDROXY ALCOHOL HAVING FROM 3 TO 5 CARBON ATOMS, BASED ON THE VOLUME CONTENT ON SAID FIRST POLISHING AGENT.
Claim 2
Dependent Claim
137 words
IN A PROCESS FOR THE PRODUCTION OF A SEMICONDUCTOR HAVING A HAZE-FREE POLISHED SURFACE BY POLISHING THE SEMICONDUCTOR WITH A POLISHING AGENT CONTAINING A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF QUARTS, A SLICIC ACID GELS OR SOLS, A SILICATE, A FLUOSILICATE, AND MIXTURES THEREOF, SAID SUBSTANCE HAVING A PARTICLE SIZE BETWEEN ABOUT 5 AND ABOUT 200 MU THE IMPROVEMENT WHICH COMPRISES FURTHER POLISHING THE SEMICONDUCTOR IN A SECOND POLISHING STEP WITH A MODIFIED POLISHING AGENT CONTAINING SAID FIRST POLISHING AGENT AND FROM ABOUT 0.01 PERCENT TO ABOUT 0.5 PERCENT BY WEIGHT OF POLYVINYL ALCOHOL CALCULATED ON THE WEIGHT OF SAID FIRST POLISHING AGENT, AND FROM ABOUT 1 PERCENT TO ABOUT 10 PERCENT BY VOLUME OF A SATURATED MONOHYDROXY ALCOHOL HAVING FROM 3 TO 5 CARBON ATOMS, BASED ON THE VOLUME CONTENT ON SAID FIRST POLISHING AGENT.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |