US3730720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication of integrated optical circuits
Assignee: AT&T Inc
•
Filing: 1970-08-05
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Granted: 1973-05-01
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Expires: 1990-08-05
Abstract
Abstract IN THIS DISCLOSURE A PROCESS IS DESCRIBED FOR THE FABRICATION OF OPTICAL INTEGRATED CIRCUITS. TTHE PROCESS CONSISTS OF FORMING A FILM OF A METAL OR ALLOY ON A SUBSTRATE, REMOVING PART OF THE FILM BY PHOTTOLITHOGRAPHIC TECHNIQUES SO AS TO FORM THE DESIRED PATTERN, AND THEN OXIDIZING THIS FILM TO THE CORRESPONDING METAL OXIDE. THE METAL OXIDE FILM ON THE SUBSTRATE FORMS THE OPTICAL INTEGRATED CIRCUIT. AN ADVANTAGE OF THIS PROCESS IS THAT PHOTOLITHOGRAPHIC TECHNIQUES CAN BE USED TO PRODUCE QUITE COMPLICATED PATTERNS OF SMALL DIMENSIONS.
Inventors
- 👤 J Cuthbert
- 👤 D Hensler
- 👤 W Orr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:31
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/0005; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |