US3666473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive photoresists for projection exposure
Assignee: International Business Machines Corp
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Filing: 1970-10-06
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Granted: 1972-05-30
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Expires: 1990-10-06
Abstract
Abstract A FAST POSITIVE PHOTORESIST COMPOSITION EMPLOYS A MIXTURE OF PHENOL-FORMALDEHYDE NOVOLAK AND RESOLE RESINS, EACH HAVING A PARTICULAR MOLECULAR WEIGHT DISTRIBUTION AS DETERMINED BY THEIR SOLUBILITIES IN AQUEOUS ALKALINE SOLUTION, TOGETHER WITH A CONVENTIONAL DIAZOKETONE TYPE OF PHOTOSENSITIZER.
Inventors
- 👤 Lucas A Colom
- 👤 Harold A Levine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:17
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/022; G03F7/023; G03F7/0233; G03F7/0236
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |