US3793175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film circuits with interconnecting contacts
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
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Filing: 1971-10-20
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Granted: 1974-02-19
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Expires: 1991-10-20
Abstract
Abstract In thin film circuits made of tantalum nitride an underlayer of tantalum is provided on the tantalum nitride layer before deposition of the contact metal layer. It is preferred to deposit the three layers in the same vacuum equipment, and to successively etch first the contacts and then the circuit pattern.
Inventors
- 👤 J Joly
- 👤 M Moulin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:34
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/18; H10; H10N; H10N97/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
17 words
A manufacturing process for thin film circuits according to claim 1 in which said metal is gold.
Claim 2
Dependent Claim
104 words
A process for manufacturing thin film circuits incorporating a tantalum nitride resistor pattern comprising the following steps: introducing a clean dielectric substrate into a vacuum vessel; sputtering a continuous tantalum nitride film on said substrate; sputtering a continuous tantalum oxide film on said substrate; sputtering a continuous tantalum film on said nitride film; sputtering a continuous contact metal film more conductive than tantalum on said tantalum film; removing the resulting multi-layer sandwich from the vacuum vessel; etching away portions of said metal film by a first photoengraving step; and etching away portions of said tantalum and tantalum nitride films by a second photo-engraving step.
Claim 3
Dependent Claim
116 words
A manufacturing process for thin film circuits incorporating a tantalum nitride resistor pattern comprising the following steps: introducing a clean dielectric substrate into a vacuum vessel; sputtering a continuous tantalum oxide film on said substrate; sputtering a continuous tantalum nitride film on said substrate; sputtering a continuous tantalum film on said nitride film; sputtering a continuous contact metal film more conductive than tantalum on said tantalum film; removing the resulting multi-layer sandwich from the vacuum vessel; etching away portions of said film by a first photoengraving step; etching away portions of said tantalum and tantalum nitride films by a second photo-engraving step; and etching away portions of said tantalum film from said tantalum nitride etched film.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |