Patent US2717086A successfully refreshed from Google Patents.
US3650796A
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US
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Photolithographic masks
Assignee: STC PLC
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Filing: 1969-05-27
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Granted: 1972-03-21
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Expires: 1989-05-27
Abstract
Abstract A method of making a photolithographic mask comprising the steps of depositing upon a transparent substrate a thin film of a polymeric material which is capable of being pyrolized to form thin film on the substrate, heating the film in order that the film is pyrolized, and removing selected areas of the pyrolized film in an oxidizing atmosphere by means of a laser beam to form the desired mask pattern.
Inventors
- 👤 Thomas Meirion Jackson
- 👤 Eric Langley Bush
- 👤 Thomas John Rowe
- 👤 David John Moule
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:23
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03F1/56; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
42 words
A method according to claim 1, wherein said film is pyrolized by heating said film for approximately 5 minutes at a temperature of approximately 150* C. and then heating said film for about 5 minutes at a temperature of approximately 400* C.
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) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |