US3607384A
Expired / Lapsed
US
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Thin-film resistors having positive resistivity profiles
Assignee: AT&T Inc
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Filing: 1968-07-11
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Granted: 1971-09-21
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Expires: 1988-07-11
Abstract
Abstract A thin-film resistor is provided having variable or nonhomogeneous resistivity which varies in a positive resistivity profile from the substrate to the film surface such that the resistivity at the surface of the thin-film is higher than the resistivity of the film adjacent to the substrate. Thin-film resistors, such as of tantalum nitride having a resistivity which varies either progressively or stepwise in a positive resistivity profile are obtained by (a) decreasing the voltage from one level to a lower level during sputtering, and/or (b) increasing the nitrogen concentration from one level to a higher level during vacuum deposition.
Inventors
- 👤 Frank D Banks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:21
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/02; H01C7/021; C; C23; C23C; C23C14/00; C23C14/0021; C23C14/0036; C23C14/0084; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
46 words
A tantalum nitride thin-film resistor comprising: a. a substrate; and b. a tantalum nitride thin film on said substrate, said tantalum nitride thin film having a resistivity which varies progressively from a low resistivity closest to the substrate to a higher resistivity furthest from said substrate.
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) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |