US4579609A
Expired / Lapsed
US
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Growth of epitaxial films by chemical vapor deposition utilizing a surface cleaning step immediately before deposition
Assignee: Massachusetts Institute of Technology
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Filing: 1984-06-08
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Granted: 1986-04-01
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Expires: 2004-06-08
Abstract
Abstract A method and apparatus for low temperature deposition of epitaxial films using low pressure chemical vapor deposition (CVD) with and without plasma enhancement. More specifically, the process enables CVD of epitaxial silicon at temperatures below 800° C. by use of an in situ argon plasma sputter cleaning treatment of the silicon substrate prior to deposition.
Inventors
- 👤 L. Rafael Reif
- 👤 Thomas J. Donahue
- 👤 Wayne R. Burger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:51
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/158; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
117 words
A chemical vapor deposition process for forming epitaxial films on a substrate at relatively low temperatures comprising the steps of: (a) cleaning the surface of the substrate in a reaction chamber to remove material which impedes epitaxial growth, while concurrently maintaining the substrate at a predetermined temperature near the deposition temperature of less than 800° C.; and (b) terminating said cleaning step (a) and immediately introducing a gaseous reactant into said reaction chamber at relatively low chamber pressure of about 10 -1 Torr or less, said reactant containing an element of the film to be deposited while maintaining the substrate at the desired deposition temperature to promptly form on said surface an epitaxial film of said element.
Claim 2
Dependent Claim
117 words
A chemical vapor deposition process for forming epitaxial films on a substrate at relatively low temperatures comprising the steps of: (a) cleaning the surface of the substrate in a reaction chamber to remove material which impedes epitaxial growth, while concurrently maintaining the substrate at a predetermined temperature near the deposition temperature of less than 800° C.; and (b) terminating said cleaning step (a) and immediately introducing a gaseous reactant into said reaction chamber at relatively low chamber pressure of about 10 -1 Torr or less, said reactant containing an element of the film to be deposited while maintaining the substrate at the desired deposition temperature to promptly form on said surface an epitaxial film of said element.
Claim 3
Dependent Claim
55 words
The process of claim 1 in which the substrate is single crystalline semiconductor, the material to be removed is SiO 2 , and the gas reactant is a gas containing Si and the cleaning is accomplished by ion bombardment caused by ions from an inert gas introduced into the chamber and evacuated before step (b).
Claim 4
Dependent Claim
19 words
The process of claim 2 in which the substrate surface temperature is 800° C. or less during film formation.
Claim 5
Dependent Claim
25 words
The process of claim 3 in which the pressure in the chamber is in the range of about 10 -3 Torr to 10 -1 Torr.
Claim 6
Dependent Claim
37 words
The process of claim 1 in which the cleaning is accomplished by ionizing an inert gas in the chamber to form a plasma and directing the ions from said inert gas towards the surface of the substrate.
Claim 7
Dependent Claim
24 words
The process of claim 5 in which the substrate surface is immersed in the inert gas plasma during step (b) to enhance film formation.
Claim 8
Dependent Claim
16 words
The process of claims 5 and 6 in which the inert gas is argon or neon.
Claim 9
Dependent Claim
94 words
An epitaxy process for depositing an epitaxial Si film comprising: (a) cleaning the surface of silicon substrate disposed in a reaction chamber to remove epitaxially growth impeding substances found on the substrate surface while keeping the substrate temperature near the deposition temperature of less than 800° C. and (b) introducing a gas reactant containing Si into the chamber at a relatively low chamber pressure of 10 -1 Torr or less to form an epitaxial film of Si from said reactant gas on said surface by chemical vapor deposition upon terminating the cleaning step (a).
Claim 10
Dependent Claim
94 words
An epitaxy process for depositing an epitaxial Si film comprising: (a) cleaning the surface of silicon substrate disposed in a reaction chamber to remove epitaxially growth impeding substances found on the substrate surface while keeping the substrate temperature near the deposition temperature of less than 800° C. and (b) introducing a gas reactant containing Si into the chamber at a relatively low chamber pressure of 10 -1 Torr or less to form an epitaxial film of Si from said reactant gas on said surface by chemical vapor deposition upon terminating the cleaning step (a).
Claim 11
Dependent Claim
31 words
The process of claim 8 in which the substrate surface temperature is maintained between the range of 400° C. to less than 800° C. during steps (a) and (b) film formation.
Claim 12
Dependent Claim
45 words
The process of claim 8 in which the cleaning in step (a) is accomplished by ion bombardment caused by ionizing an inert gas in the chamber to form a plasma and electrically directing the ions from said inert gas towards the surface of the substrate.
Claim 13
Independent Claim
158 words
A method of growing epitaxial films on a surface of substrate comprising the steps of: (a) disposing the substrate in a reaction chamber; (b) while in the reaction chamber, subjecting the surface of the substrate to a cleaning process to remove for a period of time epitaxial growth impeding substances found on the surface; (c) during a portion of the cleaning time in step (b), including just prior to termination of said cleaning, heating the substrate to bring it to a temperature at or near the deposition temperature; (d) immediately thereafter step (c) bringing the substrate to a deposition temperature of about 800° C. or less in the presence of a gas having molecules to be deposited on said surface and at a chamber pressure in the order of about 10 -1 to 10 -3 Torr to decomposed said gas and cause said decomposed elements to deposite on said surface without plasma enhancement and form an epitaxial film.
Claim 14
Independent Claim
158 words
A method of growing epitaxial films on a surface of substrate comprising the steps of: (a) disposing the substrate in a reaction chamber; (b) while in the reaction chamber, subjecting the surface of the substrate to a cleaning process to remove for a period of time epitaxial growth impeding substances found on the surface; (c) during a portion of the cleaning time in step (b), including just prior to termination of said cleaning, heating the substrate to bring it to a temperature at or near the deposition temperature; (d) immediately thereafter step (c) bringing the substrate to a deposition temperature of about 800° C. or less in the presence of a gas having molecules to be deposited on said surface and at a chamber pressure in the order of about 10 -1 to 10 -3 Torr to decomposed said gas and cause said decomposed elements to deposite on said surface without plasma enhancement and form an epitaxial film.
Claim 15
Dependent Claim
75 words
The method of claim 11 in which the substrate is Si, the cleaning is accomplished by ion bombardment and the ions are argon or neon ions formed by subjecting the inert gas to an RF field and the film is a silicon film and the gas used for deposition is taken from the group comprising: SiH 4 , SiCl 4 , SiHCl 3 , SiH 2 Cl 2 , or Si 2 H 6 .
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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) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |