Patent US5502003A successfully refreshed from Google Patents.
US5502003A
Expired / Lapsed
US
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Silicon carbide electronic device manufacturing method
Assignee: Fuji Electric Co Ltd
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Filing: 1995-03-01
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Granted: 1996-03-26
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Expires: 2015-03-01
Abstract
Abstract Reciprocal diffusion is prevented in a SiC electronic device by interposing an intermediate layer composed of W or a W-Si alloy rather than forming the Ni electrode directly on a SiC base, providing a stable electrode for which the contact resistance does not increase even when high temperatures are maintained. Bonding is facilitated when Au layer is formed on top of the Ni layer.
Inventors
- 👤 Shinji Ogino
- 👤 Tatsuo Urushidani
- 👤 Hiroshi Kanemaru
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:17
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0115; H10D64/60; H10D64/62; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
66 words
A method of manufacturing a silicon carbide electronic device, said method comprising: forming a tungsten layer on top of an n-type silicon carbide substrate; forming a conductive metal layer on the tungsten layer, wherein the conductive metal layer includes a nickel layer formed in contact with the tungsten layer; and applying a heat treatment after the conductive metal layer has been formed on the tungsten layer.
Claim 2
Independent Claim
66 words
A method of manufacturing a silicon carbide electronic device, said method comprising: forming a tungsten layer on top of an n-type silicon carbide substrate; forming a conductive metal layer on the tungsten layer, wherein the conductive metal layer includes a nickel layer formed in contact with the tungsten layer; and applying a heat treatment after the conductive metal layer has been formed on the tungsten layer.
Claim 3
Dependent Claim
31 words
A method of manufacturing the silicon carbide electronic device as described in claim 1, wherein a temperature of the heat treatment is in a range of 1,100° C. to 1,300° C.
Claim 4
Independent Claim
69 words
A method of manufacturing a silicon carbide electronic device, said method comprising; forming a tungsten-silicon alloy layer on top of an n-type silicon carbide substrate; forming a conductive metal layer on the tungsten-silicon alloy layer, wherein the conductive metal layer includes a nickel layer formed in contact with the tungsten-silicon alloy layer; and applying a heat treatment after the conductive metal layer is formed on the tungsten-silicon alloy layer.
Claim 5
Independent Claim
69 words
A method of manufacturing a silicon carbide electronic device, said method comprising; forming a tungsten-silicon alloy layer on top of an n-type silicon carbide substrate; forming a conductive metal layer on the tungsten-silicon alloy layer, wherein the conductive metal layer includes a nickel layer formed in contact with the tungsten-silicon alloy layer; and applying a heat treatment after the conductive metal layer is formed on the tungsten-silicon alloy layer.
Claim 6
Dependent Claim
35 words
A method of manufacturing a silicon carbide electronic device described in claim 3, wherein the composition of the tungsten in the tungsten-silicon alloy is in a range of 25 atomic % to 67 atomic %.
Claim 7
Dependent Claim
30 words
A method of manufacturing a silicon carbide electronic device described in claim 3, wherein a temperature of the heat treatment is in a range of 800° C. to 1,300° C.
Claim 8
Dependent Claim
30 words
A method of manufacturing a silicon carbide electronic device described in claim 4, wherein a temperature of the heat treatment is in a range of 800° C. to 1,300° C.
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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) | 1999-03-26 | 1999-09-25 | 2000-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-26 | 2003-09-25 | 2004-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-26 | 2007-09-25 | 2008-03-26 | $7700.00 | Window Closed / Lapsed |