US3672980A
Expired / Lapsed
US
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Method of rapidly detecting contaminated semiconductor surfaces
Assignee: United States Department of the Army
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Filing: 1970-12-01
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Granted: 1972-06-27
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Expires: 1990-12-01
Abstract
Abstract A SILICON SUBSTRATE IS RAPIDLY SCREENED FOR SURFACE CONTAMINATION BY EXPOSING THE SUBSTRATE SURFACE TO A CHEMICAL VAPOR ENVIRONMENT OF NITRIC OXIDE, HYDROGEN FLUORIDE AND WATER AT ABOUT 27 DEGREES C. TO OBTAIN A TRANSPARENT SURFACE FILM OF ABOUT 50 TO 100 ANGSTROMS IN THICKNESS, AND THEN EXAMINING THE FILM FOR SURFACE UNIFORMITY AND FOR THE PRESENCE OF GEOMETRIC SHAPES.
Inventors
- 👤 William B Glendinning
- 👤 Wellington B Pharo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:08
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/18; G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/8803; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P70/12; H10P70/125; H10P76/00; H10P76/40; H10P95/00; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
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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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |