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US4554045A
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Method for producing metal silicide-silicon heterostructures
Assignee: Nokia Bell Labs
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Filing: 1982-11-29
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Granted: 1985-11-19
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Expires: 2002-11-29
Abstract
Abstract Described is a method for producing semiconductor heterostructures incorporating a metal layer. The metal layer, typically a metal-silicide, can be produced by, e.g., co-deposition or reaction with the substrate. The resulting silicide is typically epitaxial and of high crystalline perfection.
Inventors
- 👤 John C. Bean
- 👤 Kin-Chung R. Chiu
- 👤 John M. Poate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:42
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10D48/362; H10D62/00; H10D62/80; H10D62/82; Y; Y10; Y10S; Y10S117/00; Y10S117/905
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
87 words
A method for forming a silicon-metal silicide heterostructure comprising essentially monocrystalline silicide grown epitaxially on a single crystal silicon substrate, the method comprising: exposing the substrate to a vapor comprising silicon and a silicide forming metal while heating the substrate to a temperature in the range of 550-850 degrees C., thereby reacting in situ the metal as it deposits and silicon to form a metal silicide essentially single crystal layer, leaving at least a portion of the substrate with said essentially single crystal metal silicide layer thereover.
Claim 2
Independent Claim
87 words
A method for forming a silicon-metal silicide heterostructure comprising essentially monocrystalline silicide grown epitaxially on a single crystal silicon substrate, the method comprising: exposing the substrate to a vapor comprising silicon and a silicide forming metal while heating the substrate to a temperature in the range of 550-850 degrees C., thereby reacting in situ the metal as it deposits and silicon to form a metal silicide essentially single crystal layer, leaving at least a portion of the substrate with said essentially single crystal metal silicide layer thereover.
Claim 3
Dependent Claim
52 words
The method of claim 1 including the additional step of epitaxially depositing silicon on the metal silicide layer while heating at least the surface of the metal silicide layer to a temperature in the range of 550-750 degrees C. thus forming a single crystal layer of silicon on the metal silicide layer.
Claim 4
Dependent Claim
21 words
The method of claim 1 or 2 in which the temperature is in the range of 600 to 700 degrees C.
Claim 5
Dependent Claim
17 words
The method of claim 1 or 2 in which the silicide forming metal is nickel or cobalt.
Claim 6
Dependent Claim
13 words
The method of claim 4 in which the silicide forming metal is nickel.
Claim 7
Dependent Claim
40 words
The method of claim 1 wherein the substrate is exposed to the vapor within a vacuum deposition chamber in which at least during part of the heterostructure-formation process a pressure of no more than about 10 -9 Torr is maintained.
Claim 8
Dependent Claim
22 words
The method of claim 1, wherein the proportion of Si to silicide forming metal in the vapor is substantially 2 to 1.
Claim 9
Independent Claim
112 words
A method for producing an article comprising an essentially monocrsytalline epitaxial layer consisting essentially of metal silicide, the layer overlying a single crystal substrate consisting essentially of silicon, the layer having χ min no larger than 10%, where χ min is the ratio of Rutherford backscattering yield for the channeling direction substantially normal to the layer to the yield in a random direction, the layer produced by a fabrication process comprising: exposing the substrate to a vapor comprising silicon and a silicide forming metal while heating the substrate to a temperature in the range of 550-850 degrees C., thereby reacting in situ the metal and silicon to form said essentially monocrystalline layer.
Claim 10
Independent Claim
112 words
A method for producing an article comprising an essentially monocrsytalline epitaxial layer consisting essentially of metal silicide, the layer overlying a single crystal substrate consisting essentially of silicon, the layer having χ min no larger than 10%, where χ min is the ratio of Rutherford backscattering yield for the channeling direction substantially normal to the layer to the yield in a random direction, the layer produced by a fabrication process comprising: exposing the substrate to a vapor comprising silicon and a silicide forming metal while heating the substrate to a temperature in the range of 550-850 degrees C., thereby reacting in situ the metal and silicon to form said essentially monocrystalline layer.
Claim 11
Dependent Claim
14 words
The method of claim 8 wherein the silicide is nickel silicide or cobalt silicide.
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) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |