US4682143A
Expired / Lapsed
US
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Thin film chromium-silicon-carbon resistor
Assignee: Advanced Micro Devices Inc
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Filing: 1985-10-30
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Granted: 1987-07-21
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Expires: 2005-10-30
Abstract
Abstract An improved thin film resistor material is disclosed which comprises a chromium-silicon-carbon material containing from about 25 to 35 wt. % chromium, about 45 to 55 wt. % silicon, and about 20 to 30 wt. % carbon. The resistor material is further characterized by a resistivity of greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 160 ppm per degree Centigrade, and a lifetime stability of less than 0.1% change in resistivity. In the preferred embodiment, the resistor material contains 31 wt. % chromium, 46 wt. % silicon, and 24 wt. % carbon.
Inventors
- 👤 John W. Chu
- 👤 Bradley J. Bereznak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:53
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/075; H01C7/00; H01C7/006; Y; Y10; Y10S; Y10S428/00; Y10S428/901
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
79 words
An improved thin film chromium-silicon-carbon resistor material comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon, and about 20 to 30 wt. % carbon and characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity.
Claim 2
Dependent Claim
79 words
An improved thin film chromium-silicon-carbon resistor material comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon, and about 20 to 30 wt. % carbon and characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity.
Claim 3
Dependent Claim
43 words
The thin film resistor material of claim 1 wherein the chromium content comprises from about 27 to 33 wt. %, the silicon content comprises from about 44 to 50 wt. %, and the carbon content comprises from about 21 to 26 wt. %.
Claim 4
Dependent Claim
43 words
The thin film resistor material of claim 2 wherein the chromium content comprises from about 28 to 31 wt. %, the silicon content comprises from about 46 to 48 wt. %, and the carbon content comprises from about 23 to 24 wt. %.
Claim 5
Dependent Claim
25 words
The thin film resistor material of claim 3 wherein said material comprises 31 wt. % chromium, 46 wt. % silicon, and 23 wt. % carbon.
Claim 6
Dependent Claim
24 words
The thin film resistor material of claim 1 wherein the material is further characterized by a temperature coefficient of expansion substantially matching silicon dioxide.
Claim 7
Dependent Claim
41 words
The thin film resistor material of claim 1 further characterized by an annealability at temperatures below 500° C. to avoid damage to any aluminum which may be already present in an integrated circuit structure to which said resistor material is applied.
Claim 8
Dependent Claim
30 words
The thin film resistor material of claim 6 which is further characterized by a resistance value which does not substantially change during subsequent processing at temperatures below the annealing temperature.
Claim 9
Dependent Claim
43 words
The thin film resistor material of claim 1 which is further characterized as a material which may be applied to a substrate by sputtering at a gas pressure of 2.0×10 -7 Torr and at a voltage range of from 1000 to 1400 volts.
Claim 10
Dependent Claim
29 words
The thin film resistor material of claim 1 which is further characterized by a uniformity of film resistance on a substrate of less than about 14% difference in resistivity.
Claim 11
Dependent Claim
189 words
An improved integrated circuit structure comprising a silicon oxide material having formed thereon one or more improved thin film chromium-silicon-carbon resistors comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon and about 20 to 30 wt. % carbon which is applicable to said structure by sputtering at a gas pressure of 2.0×10 -7 Torr or less and at a voltage range of from 1000-1400 volts and which is annealable at a temperature of less than 500° C. to provide a resistance film which will not substantially change in resistance value during subsequent exposure during processing to temperatures lower than the annealing temperature;, said resistor film being further characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a uniformity across the resistor film of not more than 14% difference in resistivity, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity and a temperature coefficient of expansion substantially matching that of the underlying silicon oxide.
Claim 12
Dependent Claim
189 words
An improved integrated circuit structure comprising a silicon oxide material having formed thereon one or more improved thin film chromium-silicon-carbon resistors comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon and about 20 to 30 wt. % carbon which is applicable to said structure by sputtering at a gas pressure of 2.0×10 -7 Torr or less and at a voltage range of from 1000-1400 volts and which is annealable at a temperature of less than 500° C. to provide a resistance film which will not substantially change in resistance value during subsequent exposure during processing to temperatures lower than the annealing temperature;, said resistor film being further characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a uniformity across the resistor film of not more than 14% difference in resistivity, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity and a temperature coefficient of expansion substantially matching that of the underlying silicon oxide.
Claim 13
Independent Claim
124 words
A method of making an improved resistor for an integrated circuit structure which comprises: (a) applying to said structure a thin film of a chromium-silicon-carbon resistor material comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon, and about 20 to 30 wt. % carbon; (b) applying a mask over said film; (c) patterning said mask; and (d) etching exposed portions of said resistor film to produce one or more resistors characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity.
Claim 14
Independent Claim
124 words
A method of making an improved resistor for an integrated circuit structure which comprises: (a) applying to said structure a thin film of a chromium-silicon-carbon resistor material comprising from about 25 to 35 wt. % chromium, about 40 to 55 wt. % silicon, and about 20 to 30 wt. % carbon; (b) applying a mask over said film; (c) patterning said mask; and (d) etching exposed portions of said resistor film to produce one or more resistors characterized by a resistivity of from greater than about 800 ohms per square to less than about 1200 ohms per square, a temperature coefficient of resistance of less than 200 ppm per degree Centigrade, and lifetime absolute and matching stability of less than 0.1% change in resistivity.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |