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US4897149A
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Method of fabricating single-crystal substrates of silicon carbide
Assignee: Sharp Corp
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Filing: 1986-06-10
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Granted: 1990-01-30
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Expires: 2006-06-10
Abstract
Abstract A single-crystal substrate of silicon carbide comprising a single-crystal substrate member of a material other than α-SiC, and a single-crystal layer of α-SiC formed over the substrate member with a ground layer provided between the substrate member and the single-crystal layer, the ground layer comprising a single-crystal layer of nitride of AlN, GaN or Al x Ga 1-x N (0<x<1) having a hexagonal crystal structure or a crystal layer of the same structure made of a mixture of SiC and at least one of the nitrides; and a method for fabricating the same.
Inventors
- 👤 Akira Suzuki
- 👤 Katsuki Furukawa
- 👤 Mitsuhiro Shigeta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:06
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B29/00; C30B29/10; C30B29/36
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
139 words
A method of fabricating a single-crystal substrate of silicon carbide comprising: (a) forming a crystal substrate base layer selected from the group consisting of: (i) a single-crystal substrate ground layer of a nitride selected from the group consisting of Aln, GaN and Al x Ga 1-x N wherein 0<x<1, said single crystal substrate ground layer having a hexagonal crystal structure, and (ii) a crystal layer of the same structure comprising a mixture of SiC and at least one of said nitrides present in an amount within the range of 0.1-10 mole % by total weight of said mixture on a single crystal substrate of a material selected from a group of materials not including alpha-SiC at a temperature from 1,200 to 1,600° C. by a CVD method; and (b) growing a single crystal of alpha-SiC on said ground layer.
Claim 2
Independent Claim
139 words
A method of fabricating a single-crystal substrate of silicon carbide comprising: (a) forming a crystal substrate base layer selected from the group consisting of: (i) a single-crystal substrate ground layer of a nitride selected from the group consisting of Aln, GaN and Al x Ga 1-x N wherein 0<x<1, said single crystal substrate ground layer having a hexagonal crystal structure, and (ii) a crystal layer of the same structure comprising a mixture of SiC and at least one of said nitrides present in an amount within the range of 0.1-10 mole % by total weight of said mixture on a single crystal substrate of a material selected from a group of materials not including alpha-SiC at a temperature from 1,200 to 1,600° C. by a CVD method; and (b) growing a single crystal of alpha-SiC on said ground layer.
Claim 3
Dependent Claim
37 words
A method as defined in claim 1 wherein the crystal layer of the mixture contains at least about 1-10 mole percent of a nitride selected from the group consisting AlN, GaN and Al x Ga 1-x N.
Claim 4
Dependent Claim
21 words
A method as defined in claim 1 wherein the crystal layer of the mixture contains about 1 mole % of AlN.
Claim 5
Dependent Claim
17 words
A method as defined in claim 1 wherein the ground layer comprises a single-crystal layer of AlN.
Claim 6
Dependent Claim
23 words
A method as defined in claim 1 wherein the ground layer and the single crystal of α-SiC are formed and grown by CVD.
Claim 7
Dependent Claim
37 words
A method as defined in claim 1 wherein the ground layer is formed to a thickness of 0.1 to 5 μm, and the single crystal of α-SiC is grown to a thickness of 1 to 10 μm.
Claim 8
Dependent Claim
31 words
A method as defined in claim 1 wherein the single-crystal substrate member consists essentially of a single crystal selected from the group consisting of Si, Al 2 O 3 and beta-SiC.
Claim 9
Dependent Claim
20 words
A method as defined in claim 1 wherein the single-crystal substrate member consists essentially of a single crystal of beta-SiC.
Claim 10
Dependent Claim
20 words
A method as defined in claim 1 wherein the single-crystal substrate member has a thickness of 1 to 500 μm.
Claim 11
Dependent Claim
141 words
A single-crystal substrate of silicon carbide comprising: (a) a single crystal substrate member of a material selected from a group of materials not including alpha-SiC; (b) a ground layer selected from the group consisting of (i) a single crystal layer of a nitride selected from the group consisting of AlN, GaN, and Al x Ga 1-x N wherein, said single crystal substrate group layer having a hexagonal crystal structure; and (ii) a single crystal layer of the same structure comprising a mixture of SiC and at least one of said nitrides present in an amount within the range of 0.1-10% mole % by total weight of said mixture, said ground layer being formed over said substrate member at a temperature from 1,000° C. to 1,800° C. by a CVD method; and (c) a single-crystal of alpha-SiC grown on said ground layer.
Claim 12
Dependent Claim
141 words
A single-crystal substrate of silicon carbide comprising: (a) a single crystal substrate member of a material selected from a group of materials not including alpha-SiC; (b) a ground layer selected from the group consisting of (i) a single crystal layer of a nitride selected from the group consisting of AlN, GaN, and Al x Ga 1-x N wherein, said single crystal substrate group layer having a hexagonal crystal structure; and (ii) a single crystal layer of the same structure comprising a mixture of SiC and at least one of said nitrides present in an amount within the range of 0.1-10% mole % by total weight of said mixture, said ground layer being formed over said substrate member at a temperature from 1,000° C. to 1,800° C. by a CVD method; and (c) a single-crystal of alpha-SiC grown on said ground layer.
Claim 13
Dependent Claim
37 words
A substrate as defined in claim 10 wherein the crystal layer of the mixture contains at least 1-10 mole % of a nitride selected from the group consisting of AlN, GaN, and Al x Ga 1-x N.
Claim 14
Dependent Claim
21 words
A substrate as defined in claim 10 wherein the crystal layer of the mixture contains about 1 mole % of AlN.
Claim 15
Dependent Claim
17 words
A substrate as defined in claim 10 wherein the ground layer comprises a single-crystal layer of AlN.
Claim 16
Dependent Claim
33 words
A substrate as defined in claim 10 wherein the ground layer has a thickness of 0.1 to 5 μm, and the single-crystal layer of α-SiC has a thickness of 1 to 10 μm.
Claim 17
Dependent Claim
30 words
A substrate as defined in claim 10 wherein the single-crystal substrate member consists essentially of a single crystal selected from the group consisting of SiAl 2 O 3 and beta-SiC.
Claim 18
Dependent Claim
20 words
A substrate as defined in claim 10 wherein the single-crystal substrate member has a thickness of 1 to 500 μm.
References Cited (Backward Citations)
GB887942A
Cited
US3634149A
Cited
US3960619A
Cited
US4028149A
Cited
US4147572A
Cited
US4161743A
Cited
US4382837A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |