Patent US2729700A successfully refreshed from Google Patents.
Patent US4510178A successfully refreshed from Google Patents.
US4510178A
Expired / Lapsed
US
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Thin film resistor material and method
Assignee: Motorola Solutions Inc
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Filing: 1983-02-14
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Granted: 1985-04-09
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Expires: 2003-02-14
Abstract
Abstract Improved thin film resistors and electrical devices and circuits with thin film resistors are fabricated utilizing a chromium, silicon, and nitrogen compound formed preferably by rf reactive sputtering of chromium and silicon in a nitrogen bearing atmosphere. An annealing step is used to produce time-stable resistance values and in combination with variations in the partial pressure of nitrogen during sputter deposition to control the temperature coefficient of resistivity to have positive, negative or zero values.
Inventors
- 👤 Wayne M. Paulson
- 👤 David W. Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:07
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/006; H01C17/00; H01C17/06; H01C17/075; H01C17/12; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
57 words
A process for fabricating a thin film resistor material on a surface of a substrate, comprising: exposing said surface to one or more sources of Cr, Si, and nitrogen; forming on said surface a thin film comprising a compound of Cr, Si, and nitrogen derived from said sources; annealing said thin film to produce said resistor material.
Claim 2
Dependent Claim
57 words
A process for fabricating a thin film resistor material on a surface of a substrate, comprising: exposing said surface to one or more sources of Cr, Si, and nitrogen; forming on said surface a thin film comprising a compound of Cr, Si, and nitrogen derived from said sources; annealing said thin film to produce said resistor material.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein at least one of said sources of Cr, Si, nitrogen, or combinations thereof is gaseous.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein said forming step comprises creating a compound of Cr, Si, and nitrogen of thickness exceeding 5 nm.
Claim 5
Dependent Claim
37 words
The process of claim 3 wherein said forming step comprises preparing a compound having a composition after annealing in the range of, expressed in atomic percent, Cr (5-75%), Si (5-85%), and nitrogen (1-60%) totalling substantially 100 percent.
Claim 6
Dependent Claim
33 words
The process of claim 3 wherein said forming step comprises preparing a compound having a composition after annealing in the range of Cr (15-35%), Si (47-83%), and nitrogen (2-18%) expressed in atomic percent.
Claim 7
Dependent Claim
33 words
The process of claim 3 wherein said forming step comprises preparing a compound having a composition after annealing in the range of Cr (25-29%), Si (55-67%), and nitrogen (8-16%) expressed in atomic percent.
Claim 8
Dependent Claim
25 words
The process of claim 4 wherein said annealing step comprises heating said thin film to a temperature less than 1000° C. in a dry atmosphere.
Claim 9
Dependent Claim
24 words
The process of claim 7 wherein said atmosphere comprises N 2 , O 2 , H 2 , Ar, He, or dry mixtures thereof.
Claim 10
Dependent Claim
21 words
The process of claim 8 wherein said forming step comprises reactive sputtering of Cr and Si in a nitrogen bearing gas.
Claim 11
Dependent Claim
15 words
The process of claim 9 wherein said nitrogen bearing gas comprises N 2 and Ar.
Claim 12
Dependent Claim
39 words
The process of claim 10 wherein said forming process comprises rf reactive sputtering and said N 2 and Ar are in a pressure ratio of 1-20% partial pressure of nitrogen in a predetermined total pressure of argon plus nitrogen.
Claim 13
Dependent Claim
21 words
The process of claim 11 wherein said total pressure is in the range 4 to 50 microns (0.53 to 6.7 Pa).
Claim 14
Dependent Claim
22 words
The process of claim 12 wherein said total pressure is in the range of 6 to 20 microns (0.8 to 2.7 Pa).
Claim 15
Dependent Claim
29 words
The process of claim 13 wherein said reactive sputtering step includes depositing a layer comprising Cr, Si, and nitrogen having a thickness in the range 40 to 100 nm.
Claim 16
Dependent Claim
17 words
The process of claim 14 wherein said heating step is carried out between 400° to 800° C.
Claim 17
Dependent Claim
11 words
The process of claim 15 wherein said substrate comprises a semiconductor.
Claim 18
Dependent Claim
13 words
The process of claim 15 wherein said surface has thereon an insulator layer.
Claim 19
Dependent Claim
12 words
The process of claim 17 wherein said insulator layer comprises silicon oxide.
Claim 20
Dependent Claim
19 words
The process of claim 18 wherein said insulator layer comprises silicon oxide and an outer layer of silicon nitride.
References Cited (Backward Citations)
US3381255A
Cited
US3477935A
Cited
FR1543297A
Cited
US3847658A
Cited
US4042479A
Cited
FR2351478A1
Cited
US4079349A
Cited
US4217570A
Cited
US4288776A
Cited
US4298505A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |