Patent US6139624A successfully refreshed from Google Patents.
US6139624A
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Process for producing an electrical contact on a SIC surface
Assignee: Infineon Technologies AG
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Filing: 1996-03-29
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Granted: 2000-10-31
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Expires: 2016-03-29
Abstract
Abstract Method for producing an electrical contact on a SiC surface A carbon coating (4), preferably a graphite coating, is first created on the silicon carbide surface (3). Said carbon coating (4) is then converted, with a carbide-forming metal (Me), into a metal carbide coating (7). The SiC/metal carbide contact produced thereby forms, in particular, an almost perfect Schottky contact.
Inventors
- 👤 Roland Rupp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:39
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D64/00; H10D64/01; H10D64/012; H10D64/0121; H10D64/0123
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
76 words
A method for producing an electrical contact on a silicon carbide surface (3), comprising the steps of: a) producing by epitaxial deposition a SiC crystal (2) having said silicon carbide surface (3); b) producing a carbon coating (4) on said silicon carbide surface (3) by interrupting silicon delivery during said epitaxial deposition and by delivering only carbon; and c) converting the carbon coating (4) at least largely into metal carbide with at least one carbide-forming metal.
Claim 2
Independent Claim
76 words
A method for producing an electrical contact on a silicon carbide surface (3), comprising the steps of: a) producing by epitaxial deposition a SiC crystal (2) having said silicon carbide surface (3); b) producing a carbon coating (4) on said silicon carbide surface (3) by interrupting silicon delivery during said epitaxial deposition and by delivering only carbon; and c) converting the carbon coating (4) at least largely into metal carbide with at least one carbide-forming metal.
Claim 3
Dependent Claim
24 words
The method as defined in claim 1, wherein the SiC single crystal (2) and the carbon coating (4) are produced by chemical vapor deposition.
Claim 4
Dependent Claim
24 words
The method as defined in claim 1, wherein the SiC single crystal (2) and the carbon coating (4) are produced by molecular beam epitaxy.
Claim 5
Dependent Claim
63 words
The method as defined in claim 1, wherein the silicon carbide surface (3) is formed with a silicon plane of the SiC single crystal (2) that corresponds in the case of a cubic polytype of SiC (β-SiC) to a (1 1 1) crystal surface, and that corresponds in the case of a non-cubic polytype (α-SiC) to a (0 0 0 1) crystal surface.
Claim 6
Dependent Claim
63 words
The method as defined in claim 1, wherein the silicon carbide surface (3) is formed with a carbon plane of the SiC single crystal (2) that corresponds in the case of a cubic polytype of SiC (β-SiC) to a (-1 -1 -1) crystal surface, and that corresponds in the case of a non-cubic polytype (α-SiC) to a (0 0 0 -1) crystal surface.
Claim 7
Dependent Claim
23 words
The method as defined in claim 1, wherein the carbon coating (4) has a substantially graphite crystalline structure or a graphite-like crystalline structure.
Claim 8
Dependent Claim
23 words
The method as defined in claim 1, wherein the carbon coating (4) is created to have a thickness of less than 1 nm.
Claim 9
Dependent Claim
37 words
The method as defined in claim 1, wherein an element selected from the group consisting of tungsten (W), titanium (Ti), tantalum (Ta), boron (B), aluminum (Al), nickel (Ni), and scandium (Sc) is used as the carbide-forming metal.
Claim 10
Dependent Claim
23 words
The method as defined in claim 1, wherein the at least one carbide-forming metal is brought to the carbon coating (4) by sputtering.
Claim 11
Dependent Claim
36 words
The method as defined in claim 9, wherein the kinetic energy of the metal atoms or metal ions is set to be at least as great as the chemical formation energy of the associated metal carbide.
Claim 12
Dependent Claim
34 words
The method as defined in claim 1, wherein the carbide-forming metal is first applied onto the carbon coating (4) and then caused to react chemically with the carbon by means of a temperature treatment.
Claim 13
Dependent Claim
18 words
The method as defined in claim 11, wherein the carbide-forming metal is evaporated onto the carbon coating (4).
Claim 14
Independent Claim
102 words
A method for producing an electrical contact on a silicon surface (3), comprising the steps of: a) producing a SiC crystal (2) by epitaxial deposition at a temperature between approximately 1000° C. and approximately 1800° C. said SiC single crystal (2) having said silicon carbide surface (3), immediately followed by b) cooling the SiC single crystal (2) in vacuum or in an inert gas atmosphere, wherein the carbon coating (4) is produced by evaporating silicon atoms off from said silicon carbide surface (3), and c) converting the carbon coating (4) at least largely into metal carbide with at least one carbide-forming metal.
Claim 15
Independent Claim
102 words
A method for producing an electrical contact on a silicon surface (3), comprising the steps of: a) producing a SiC crystal (2) by epitaxial deposition at a temperature between approximately 1000° C. and approximately 1800° C. said SiC single crystal (2) having said silicon carbide surface (3), immediately followed by b) cooling the SiC single crystal (2) in vacuum or in an inert gas atmosphere, wherein the carbon coating (4) is produced by evaporating silicon atoms off from said silicon carbide surface (3), and c) converting the carbon coating (4) at least largely into metal carbide with at least one carbide-forming metal.
Claim 16
Dependent Claim
19 words
The method as defined in claim 13, wherein the SiC single crystal (2) is produced by chemical vapour deposition.
Claim 17
Dependent Claim
19 words
The method as defined in claim 13, wherein the SiC single crystal (2) is produced by molecular beam epitaxy.
Claim 18
Dependent Claim
63 words
The method as defined in claim 13, wherein the silicon carbide surface (3) is formed with a silicon plane of the SiC single crystal (2) that corresponds in the case of a cubic polytype of SiC (β-SiC) to a (1 1 1) crystal surface, and that corresponds in the case of a non-cubic polytype (α-SiC) to a (0 0 0 1) crystal surface.
Claim 19
Dependent Claim
63 words
The method as defined in claim 13, wherein the silicon carbide surface (3) is formed with a carbon plane of the SiC single crystal (2) that corresponds in the case of a cubic polytype of SiC (β-SiC) to a (--1 -1 -1) crystal surface, and that corresponds in the case of a non-cubic polytype (α-SiC) to a (0 0 0 -1) crystal surface.
Claim 20
Dependent Claim
23 words
The method as defined in claim 13, wherein the carbon coating (4) has a substantially graphite crystalline structure or a graphite-like crystalline structure.
Claim 21
Dependent Claim
23 words
The method as defined in claim 13, wherein the carbon coating (4) is created to have a thickness of less than 1 nm.
Claim 22
Dependent Claim
37 words
The method as defined in claim 13, wherein an element selected from the group consisting of tungsten (W), titanium (Ti), tantalum (Ta), boron (B), aluminum (Al), nickel (Ni), and scandium (Sc) is used as the carbide-forming metal.
Claim 23
Dependent Claim
23 words
The method as defined in claim 13, wherein the at least one carbide-forming metal is brought to the carbon coating (4) by sputtering.
Claim 24
Dependent Claim
36 words
The method as defined in claim 21, wherein the kinetic energy of the metal atoms or metal ions is set to be at least as great as the chemical formation energy of the associated metal carbide.
Claim 25
Dependent Claim
34 words
The method as defined in claim 13, wherein the carbide-forming metal is first applied onto the carbon coating (4) and then caused to react chemically with the carbon by means of a temperature treatment.
Claim 26
Dependent Claim
18 words
The method as defined in claim 23, wherein the carbide-forming metal is evaporated onto the carbon coating (4).
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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) | 2003-10-31 | 2004-05-01 | 2004-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-31 | 2008-05-01 | 2008-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-31 | 2012-05-01 | 2012-10-31 | $7700.00 | Window Closed / Lapsed |