US4661176A
Expired / Lapsed
US
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Process for improving the quality of epitaxial silicon films grown on insulating substrates utilizing oxygen ion conductor substrates
Assignee: United States Department of the Air Force
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Filing: 1985-02-27
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Granted: 1987-04-28
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Expires: 2005-02-27
Abstract
Abstract The present invention accomplishes the thermal oxidation of the silicon side of the interface present in epitaxial silicon films grown on yttria-stabilized cubic zirconia, <Si>/<YSZ>, to form a dual-layer structure of <Si>/amorphous SiO 2 /<YSZ>. The SiO 2 films are formed in either dry oxygen (at 1100° C.) or in pyrogenic steam (at 925° C.) by the rapid diffusion of oxidizing species through a 425 μm thick cubic zirconia substrate. For instance, a 0.17 μm thick SiO 2 layer is obtained after 100 min in pyrogenic steam at 925° C. This relatively easy transport of oxidants is unique to YSZ and other insulators which are also superionic oxygen conductors, and cannot be achieved in other existing Si/insulator systems, such as silicon-on-sapphire.
Inventors
- 👤 Harold M. Manasevit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:04
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69395; H10P14/20; H10P14/29; H10P14/2901; H10P14/2921; H10P14/2926; H10P14/32; H10P14/3202; H10P14/3238; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P14/66; H10P14/662; H10P14/69396; H10P14/69397; Y; Y10; Y10S; Y10S117/00; Y10S117/915; Y10S148/00; Y10S148/003; Y10S148/117; Y10S148/15; Y10S438/00; Y10S438/967
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
96 words
A method for treating films, said method comprising the steps of: a. depositing a thin, heteroepitaxial silicon film onto a surface of an insulator substrate being an oxygen ion conductor thereby forming a silicon-substrate interface between said film and said substrate; b. protecting the surface of said silicon film from oxidation; c. subjecting said substrate to an oxidizing environment at a temperature and for a period of time sufficient to form a silicon dioxide layer at said interface; and d. removing said oxidizing environment from said substrate after said silicon dioxide layer reaches a predetermined thickness.
Claim 2
Independent Claim
96 words
A method for treating films, said method comprising the steps of: a. depositing a thin, heteroepitaxial silicon film onto a surface of an insulator substrate being an oxygen ion conductor thereby forming a silicon-substrate interface between said film and said substrate; b. protecting the surface of said silicon film from oxidation; c. subjecting said substrate to an oxidizing environment at a temperature and for a period of time sufficient to form a silicon dioxide layer at said interface; and d. removing said oxidizing environment from said substrate after said silicon dioxide layer reaches a predetermined thickness.
Claim 3
Dependent Claim
23 words
A method as defined in claim 1 wherein said oxidizing environmental is selected from the group consisting of dry oxygen and pyrogenic steam.
Claim 4
Dependent Claim
46 words
A method as defined in claim 1 wherein said substrate is subjected to said oxidizing environment maintained at about 925° C. and comprising, in sequence, a flow of nitrogen, a flow of said oxidizing environment, and a flow of nitrogen, said flows being for preselected times.
Claim 5
Dependent Claim
13 words
A method as defined in claim 1 wherein said substrate is cubic zirconia.
Claim 6
Dependent Claim
25 words
A method as defined in claim 4 wherein said substrate is stabilized with a compound selected from the group consisting of yttria and calcium oxide.
Claim 7
Dependent Claim
41 words
A method as defined in claim 5 wherein said substrate has the composition (Y 2 O 3 ) m (Z r O 2 ) 1-m and said yttria mole fraction is in the range of from about 0.09 to about 0.33.
Claim 8
Dependent Claim
28 words
A method as defined in claim 1 wherein a protective layer is deposited on said silicon film before exposing said substrate and said film to said oxidizng environment.
Claim 9
Dependent Claim
14 words
A method as defined in claim 7, wherein said protective layer is silicon nitride.
Claim 10
Dependent Claim
23 words
A method as defined in claim 1 wherein said substrate has an orientation selected for the group consisting of (111), (110) and (100).
Claim 11
Independent Claim
113 words
A method for treating films, said method comprising the steps of: a. depositing a thin, heteroepitaxial silicon film onto a surface of an insulator substrate being an oxygen ion conductor thereby forming a silicon-substrate interface between said film and said substrate; b. protecting the surface of said silicon film from oxidation; c. subjecting said substrate to an oxidizing environment at a temperature and for a period of time sufficient to form a silicon dioxide layer at said interface; d. removing said oxidizing environment from said substrate after said silicon dioxide layer reaches a predetermined thickness; and e. separating said silicon film from said substrate by dissolving said silicon dioxide layer at said interface.
Claim 12
Independent Claim
113 words
A method for treating films, said method comprising the steps of: a. depositing a thin, heteroepitaxial silicon film onto a surface of an insulator substrate being an oxygen ion conductor thereby forming a silicon-substrate interface between said film and said substrate; b. protecting the surface of said silicon film from oxidation; c. subjecting said substrate to an oxidizing environment at a temperature and for a period of time sufficient to form a silicon dioxide layer at said interface; d. removing said oxidizing environment from said substrate after said silicon dioxide layer reaches a predetermined thickness; and e. separating said silicon film from said substrate by dissolving said silicon dioxide layer at said interface.
Claim 13
Dependent Claim
23 words
A method as defined in claim 10 wherein said oxidizing environment is selected from the group consisting of dry oxygen and pyrogenic steam.
Claim 14
Dependent Claim
46 words
A method as defined in claim 10 wherein said substrate is subjected to said oxidizing environment maintained at about 925° C. and comprising, in sequence, a flow of nitrogen, a flow of said ozidizing environment, and a flow of nitrogen, said flows being for preselected times.
Claim 15
Dependent Claim
13 words
A method as defined in claim 10 wherein said substrate is cubic zirconia.
Claim 16
Dependent Claim
25 words
A method as defined in claim 13 wherein said substrate is stabilized with a compound selected from the group consisting of yttria and calcium oxide.
Claim 17
Dependent Claim
41 words
A method as defined in claim 10 wherein said substrate has the composition (Y 2 O 3 ) m (Z r O 2 ) 1-m and said yttria mole fraction is in the range of from about 0.09 to about 0.33.
Claim 18
Dependent Claim
28 words
A method as defined in claim 10 wherein a protective layer is deposited on said silicon film before exposing said substrate and said film to said oxidizing environment.
Claim 19
Dependent Claim
14 words
A method as defined in claim 16 wherein a protective layer is silicon nitride.
Claim 20
Dependent Claim
23 words
A method as defined in claim 10 wherein said substrate has an orientation selected for the group consisting of (111), (110) and (100).
References Cited (Backward Citations)
US4177321A
Cited
US4116751A
Cited
US4177084A
Cited
US4275093A
Cited
US4447497A
Cited
US4540452A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-04-27 | 1990-10-27 | 1991-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-27 | 1994-10-27 | 1995-04-28 | $3760.00 | Window Closed / Lapsed |
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