US3814641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of fabricating silicon photomask
Assignee: INSTR Inc
•
Filing: 1972-07-20
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Granted: 1974-06-04
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Expires: 1992-07-20
Abstract
Abstract AN IMPROVED "SEE-THROUGH" PHOTOMASK OF SILICON PATTERNED ON GLASS IS PRODUCED BY THE LOW-TEMPERATURE DEPOSITION OF SILICON, FOLLOWED BY THE LOW-TEMPERATURE DEPOSITION OF SILICON NITRIDE OR SILICON OXIDE ON THE SILICON. THE NITRIDE OR OXIDE IS THEN PATTERNED BY SELECTIVE ETCHING FOR USE AS AN ETCH-RESISTANT MASK IN THE SELECTIVE ETCHING OF THE SILICON TO PRODUCE THE PHOTOMASK. PREFERABLY, THE NITRIDE OR OXIDE PATTERN IS LEFT ON THE SILICON PATTERN AS AN ANTI-REFLECTION COATING.
Inventors
- 👤 A Reinberg
- 👤 J Fish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:37
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/50; Y; Y10; Y10S; Y10S148/00; Y10S148/051; Y10S148/085; Y10S148/106; Y10S148/15
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) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |