Patent US4091781A successfully refreshed from Google Patents.
Patent US4975387A successfully refreshed from Google Patents.
US4975387A
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Formation of epitaxial si-ge heterostructures by solid phase epitaxy
Assignee: United States Department of the Navy
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Filing: 1989-12-15
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Granted: 1990-12-04
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Expires: 2009-12-15
Abstract
Abstract Epitaxial Si-Ge heterostructures are formed by depositing a layer of amorphous Si-Ge on a silicon wafer. The amorphous Si-Ge on the silicon wafer is then subjected to a wet oxidation in order to form an epitaxial Si-Ge heterostructure. Any size wafer may be used and no special precaustions need be taken to ensure a clean amorphous Si-Ge/Si interface.
Inventors
- 👤 Sharka M. Prokes
- 👤 Wen F. Tseng
- 👤 Aristos Christou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:13
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2926; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/36; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/048; Y10S148/059; Y10S148/072; Y10S148/154
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
41 words
A method of forming epitaxial Si-Ge heterostructures comprising: depositing a layer of amorphous Si-Ge on a silicon wafer; and wet oxidizing said amorphous Si-Ge deposited on said silicon wafer at a temperature and time sufficient to form an epitaxial Si-Ge heterostructure.
Claim 2
Independent Claim
41 words
A method of forming epitaxial Si-Ge heterostructures comprising: depositing a layer of amorphous Si-Ge on a silicon wafer; and wet oxidizing said amorphous Si-Ge deposited on said silicon wafer at a temperature and time sufficient to form an epitaxial Si-Ge heterostructure.
Claim 3
Dependent Claim
27 words
A method as described in claim 1 wherein said silicon wafer is selected from the group comprising Si(100) at about 0° to about 6° to <010> wafers.
Claim 4
Dependent Claim
15 words
A method as described in claim 2 wherein said silicon wafer is an Si(100) wafer.
Claim 5
Dependent Claim
25 words
A method as described in claim 1 wherein said silicon wafer is doped prior to depositing said layer of amorphous Si-Ge on said silicon wafer.
Claim 6
Dependent Claim
20 words
A method as described in claim 4 wherein said dopant is selected from the group comprising boron, phosphorous and arsenic.
Claim 7
Dependent Claim
24 words
A method as described in claim 4 wherein said silicon wafer is doped at a range of between about 0.1Ω-cm to about 300Ω-cm resistivity.
Claim 8
Dependent Claim
19 words
A method as described in claim 1 wherein said silicon wafer has any contaminants removed from said silicon wafer.
Claim 9
Dependent Claim
19 words
A method as described in claim 7 wherein said contaminants are removed by means of an RCA cleaning method.
Claim 10
Dependent Claim
21 words
A method as described in claim 1 wherein said amorphous Si-Ge layer is deposited by means of vacuum evaporation or sputtering.
Claim 11
Dependent Claim
13 words
A method as described in claim 9 wherein the means is vacuum evaporation.
Claim 12
Dependent Claim
29 words
A method as described in claim 1 wherein the ratio of Si to Ge is Si x Ge 1-x where x is less than 1 and greater than 0.
Claim 13
Dependent Claim
16 words
A method as described in claim 11 wherein x is between about 0.1 and about 0.9.
Claim 14
Dependent Claim
27 words
A method as described in claim 1 wherein the temperature is high enough to produce epitaxial Si-Ge but low enough so that the Ge does not evaporate.
Claim 15
Dependent Claim
18 words
A method as described in claim 13 wherein the temperature is between about 800° C. and about 1000°C.
Claim 16
Dependent Claim
14 words
A method as described in claim 14 wherein the temperature is about 900° C.
Claim 17
Independent Claim
74 words
A method of forming epitaxial Si-Ge heterostructures comprising: doping a silicon wafer to form a doped silicon wafer; removing contaminants from said doped silicon wafer to form a cleaned doped silicon wafer; depositing a layer of amorphous Si-Ge on said cleaned doped silicon wafer to form an amorphous Si-Ge/Si wafer; removing contaminants from said Si-Ge/Si wafer; wet oxidizing said amorphous Si-Ge/Si wafer at a temperature and time sufficient to form an epitaxial Si-Ge heterostructure.
Claim 18
Independent Claim
74 words
A method of forming epitaxial Si-Ge heterostructures comprising: doping a silicon wafer to form a doped silicon wafer; removing contaminants from said doped silicon wafer to form a cleaned doped silicon wafer; depositing a layer of amorphous Si-Ge on said cleaned doped silicon wafer to form an amorphous Si-Ge/Si wafer; removing contaminants from said Si-Ge/Si wafer; wet oxidizing said amorphous Si-Ge/Si wafer at a temperature and time sufficient to form an epitaxial Si-Ge heterostructure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |