Patent US3701659A successfully refreshed from Google Patents.
US3701659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photolithographic masks of semiconductor material
Assignee: International Business Machines Corp
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Filing: 1970-06-01
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Granted: 1972-10-31
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Expires: 1990-06-01
Abstract
Abstract A PHOTOLITHOGRAPHIC MASK COMPRISING A SUBSTRATE OF QUARTZ OR GLASS AND A PATTERN-DEFINING LAYER OF A SEMICONDUCTOR MATERIAL SUCH AS SILICON. THE PATTERN IS DEFINED IN THE SEMICONDUCTOR MATERIAL BY ETCHING OF THE SEMICONDUCTOR, INVOLVING DISPLACEMENT OF THE SEMICONDUCTOR IN SELECTED AREAS WITH A METAL SUCH AS COPPER. IN THIS WAY, A HIGH RESOLUTION MASK IS OBTAINABLE HAVING THE ADDED FEATURE OF BEING PARTIALLY TRANSPARENT.
Inventors
- 👤 Ven Y Doo
- 👤 Joseph Regh
- 👤 David K Seto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:14
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54
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) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |