US3665599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making refractory metal carbide thin film resistors
Assignee: Corning Glass Works
•
Filing: 1970-04-27
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Granted: 1972-05-30
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Expires: 1990-04-27
Abstract
Abstract The resistance value of a refractory metal carbide film resistor is adjusted and stabilized at any desired resistance value up to approximately 100 times the resistance value of the originally deposited film by heat treating the metal carbide film in an oxidizing atmosphere at temperatures above the anticipated operating range of the resistor. The heat treatment increases the resistance of the applied film by converting a layer of the exposed film to a non-conductive oxide.
Inventors
- 👤 Andrew Herczog
- 👤 Harold R Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:49
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/26; H01C17/265; H01C7/00; H01C7/22; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
22 words
The method of claim 1 wherein the insulating substrate is selected from the group consisting of alkali-free glass and thermally oxidized silicon.
Claim 2
Dependent Claim
25 words
The method of claim 1 further comprising the step of applying electrically conductive terminals to the substrate prior to depositing the refractory metal carbide film.
Claim 3
Dependent Claim
19 words
The method of claim 3 wherein the electrically conductive terminals are an alloy made from aluminum, gold and chrome.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the step of depositing said film of refractory metal carbide is by vacuum vapor deposition.
Claim 5
Dependent Claim
15 words
The method of claim 5 wherein said film of refractory metal carbide is titanium carbide.
Claim 6
Dependent Claim
34 words
The method of claim 6 further comprising the step of degassing the titanium carbide in a vacuum not less that 10 4 torr at approximately 1,000* C. prior to being deposited on said substrate.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein said converting and stabilizing steps are performed simultaneously.
Claim 8
Dependent Claim
18 words
The method of claim 8 wherein the converting and stabilizing steps are continued for at least 1 hour.
Claim 9
Dependent Claim
38 words
The method of claim 1 further comprising the step of masking portions of the film surface prior to any heat treatment to prevent refractory metal carbide below said masked surface from being convErted to a refractory metal oxide.
Claim 10
Dependent Claim
44 words
The method of claim 10 further comprising the steps of patterning said mask to increase the length-to-width ratio of the masked portions of refractory metal carbide, and then converting the unmasked portions of refractory metal carbide, throughout its entire thickness, to refractory metal oxide.
Claim 11
Dependent Claim
19 words
The method of claim 1 further comprising the step of applying a layer of glass over said combination film.
Claim 12
Independent Claim
181 words
A method of producing thin film resistors comprising the steps of providing an alkali-free glass substrate, forming spaced terminals from an aluminum, gold and chrome alloy at desired locations on said substrate, depositing a 100 A.-5,000 A. film of degassed titanium carbide over said terminals and the surface of said substrate by vacuum vapor deposition, converting a layer of said titanium carbide to a non-conductive titanium oxide to form a combination film of conductive titanium carbide and non-conductive titanium oxide which has a higher sheet resistance than the deposited all titanium carbide film thereby adjusting the sheet resistance of said deposited titanium carbide film by heating the substrate-titanium carbide film structure in an oxidizing atmosphere to a temperature between 200* C. and 260* C., and stabilizing the sheet resistance of said combination film by heating said combination film in oxidizing atmosphere to a temperature between 180* C. and 220* C., which temperature is no greater than the temperature used for converting the layer of titanium carbide to titanium oxide, said step of converting occurring no later than said step of stabilizing.
Claim 13
Dependent Claim
14 words
The method of claim 13 wherein said converting and stabilizing steps are performed simultaneously.
Claim 14
Dependent Claim
18 words
The method of claim 14 wherein the converting and stabilizing steps are continued for at least 1 hour.
Claim 15
Dependent Claim
35 words
The method of claim 13 further comprising the step of masking portions of the film surface prior to any heat treatment to prevent titanium carbide below said masked surface from being converted to titanium oxide.
Claim 16
Dependent Claim
42 words
The method of claim 16 further comprising the steps of patterning said mask to increase the length-to-width ratio of the masked portions of titanium carbide, and then completely converting the unmasked portions of titanium carbide throughout its entire thickness, to titanium oxide.
Claim 17
Dependent Claim
19 words
The method of claim 13 further comprising the step of applying a layer of glass over said combination film.
Claim 18
Independent Claim
103 words
A method of producing thin film resistors comprising the steps of providing an insulating substrate, depositing a 100 A.-5,000 A. film of a refractory metal carbide on the surface of said insulating substrate, said refractory metal being selected from the group consisting of titanium, zirconium, vanadium, niobium, tantalum, hafnium, chromium, tungsten, molybdenum, and combinations thereof, masking portions of the surface of said film with a patterned mask, converting the entire thickness of the unmasked portions of said film to a refractory metal oxide, thereby producing a patterned resistive film of refractory metal carbide having a large effective length-to-width ratio, and removing said mask.
Claim 19
Dependent Claim
156 words
The method of claim 19 further comprising the steps of converting a layer of said refractory metal carbide to a non-conductive refractory metal oxide to form a combination film of refractory metal carbide and refractory metal oxide which has a higher sheet resistance than the deposited all refractory metal carbide film thereby adjusting the sheet resistance of the remaining refractory metal carbide film by heating the substrate-film structure in an oxidizing atmosphere to a temperature between 180* C. and 400* C., and stabilizing the sheet resistance of the combination film by heating the substrate-film structure in an oxidizing atmosphere to a tempErature between 150* C. and 220* C., which temperature is no greater than the temperature used for converting the layer of refractory metal carbide to a refractory metal oxide, the step of converting the sheet resistance of the deposited film occuring no later than the step of stabilizing the sheet resistance of the combination film.
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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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |