US4227944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of making composite conductive structures in integrated circuits
Assignee: General Electric Co
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Filing: 1979-06-11
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Granted: 1980-10-14
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Expires: 1999-06-11
Abstract
Abstract A method of making a composite conductive structure is described. The structure includes an insulating substrate on which is provided a conductor of a refractory metal substantially nonreactive with silicon dioxide covered by a layer of a silicide of the refractory metal and a layer of silicon dioxide. The method includes depositing a layer of polycrystalline silicon over the conductor and the insulating substrate, reacting the layer of polycrystalline silicon with the conductor to form a refractory metal silicide, removing the unreacted portion of the layer of polycrystalline silicon, and then oxidizing the exposed surface of the refractory metal silicide into a layer of silicon dioxide.
Inventors
- 👤 Dale M. Brown
- 👤 Tat-Sing P. Chow
- 👤 James F. Gibbons
- 👤 Paul A. McConnelee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:40
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01322; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/066; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4437; H10W20/4441; Y; Y10; Y10S; Y10S148/00; Y10S148/103; Y10S148/141; Y10S148/147
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
199 words
A method of forming a composite structure comprising providing a substrate of semiconductor material having an overlying layer of insulating material, forming a conductor of a refractory metal which is substantially nonreactive with silicon dioxide in a desired pattern overlying said layer of insulating material, forming over said conductor of metallic material and said layer of insulating material a layer of polycrystalline silicon, heating said substrate including said conductor of metallic material and said overlying layer of polycrystalline silicon to a temperature and for a time to cause said layer of polycrystalline silicon to react with a portion of said conductor to form a layer of a silicide of said metallic material overlying a remaining portion of said conductor unconverted to a silicide thereof, removing the portion of said layer of polycrystalline silicon which has not reacted with said metallic material, heating said substrate including said conductor and said layer of said metal silicide in an oxidizing atmosphere at a temperature and for a time to cause said oxidizing atmosphere to react with said layer of said silicide to convert a portion thereof to silicon dioxide overlying another portion of said layer of said silicide unconverted to silicon dioxide.
Claim 2
Independent Claim
199 words
A method of forming a composite structure comprising providing a substrate of semiconductor material having an overlying layer of insulating material, forming a conductor of a refractory metal which is substantially nonreactive with silicon dioxide in a desired pattern overlying said layer of insulating material, forming over said conductor of metallic material and said layer of insulating material a layer of polycrystalline silicon, heating said substrate including said conductor of metallic material and said overlying layer of polycrystalline silicon to a temperature and for a time to cause said layer of polycrystalline silicon to react with a portion of said conductor to form a layer of a silicide of said metallic material overlying a remaining portion of said conductor unconverted to a silicide thereof, removing the portion of said layer of polycrystalline silicon which has not reacted with said metallic material, heating said substrate including said conductor and said layer of said metal silicide in an oxidizing atmosphere at a temperature and for a time to cause said oxidizing atmosphere to react with said layer of said silicide to convert a portion thereof to silicon dioxide overlying another portion of said layer of said silicide unconverted to silicon dioxide.
Claim 3
Dependent Claim
23 words
The method of claim 1 in which said refractory metal is selected from the class consisting of molybdenum, tungsten, tantalum, platinum and palladium.
Claim 4
Dependent Claim
12 words
The method of claim 2 in which said metallic material is molybdenum.
Claim 5
Dependent Claim
12 words
The method of claim 2 in which said metallic material is tungsten.
Claim 6
Dependent Claim
12 words
The method of claim 2 in which said metallic material is tantalum.
Claim 7
Dependent Claim
12 words
The method of claim 2 in which said metallic material is platinum.
Claim 8
Dependent Claim
12 words
The method of claim 2 in which said metallic material is palladium.
Claim 9
Dependent Claim
36 words
The method of claim 1 in which the unreacted portion of said layer of polycrystalline silicon is removed by etching with an etchant which etches polycrystalline silicon substantially faster than said silicide of said metallic material.
Claim 10
Dependent Claim
16 words
The method of claim 8 in which said etchant is an aqueous solution of potassium hydroxide.
Claim 11
Dependent Claim
20 words
The method of claim 1 in which said layer of polycrystalline silicon is provided by chemical vapor deposition of silicon.
Claim 12
Dependent Claim
31 words
The method of claim 1 in which the temperature to which said substrate is heated to cause said layer of polycrystalline silicon to react with said conductor is above 1000° C.
Claim 13
Dependent Claim
31 words
The method of claim 1 in which said substrate is heated at a temperature and for a time to convert substantially all of said layer of said silicide to silicon dioxide.
Claim 14
Dependent Claim
13 words
The method of claim 1 in which said insulating material is silicon dioxide.
Claim 15
Dependent Claim
34 words
The method of claim 1 in which said layer of insulating material is constituted of a layer of silicon nitride overlying a layer of silicon dioxide, said conductor overlying said layer of silicon nitride.
Claim 16
Dependent Claim
19 words
The method of claim 1 in which said insulating material is a composite of silicon dioxide and silicon nitride.
Claim 17
Dependent Claim
12 words
The method of claim 1 in which said semiconductor material is silicon.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |