Patent US5170231A successfully refreshed from Google Patents.
US5170231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide field-effect transistor with improved breakdown voltage and low leakage current
Assignee: Sharp Corp
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Filing: 1991-05-24
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Granted: 1992-12-08
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Expires: 2011-05-24
Abstract
Abstract A silicon carbide field-effect transistor is provided which includes a semiconductor substrate, a channel formation layer of silicon carbide formed above the substrate, source and drain regions provided in contact with the channel formation layer, a gate insulator disposed between the source and drain regions, and a gate electrode formed on the gate insulator, wherein a first contact between the channel formation layer and the drain region exhibits different electric characteristics from those of a second contact between the channel formation layer and the source region. Also provided is a method for producing such a silicon carbide field-effect transistor.
Inventors
- 👤 Yoshihisa Fujii
- 👤 Akira Suzuki
- 👤 Katsuki Furukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D12/00; H10D12/01; H10D12/031; H10D64/00; H10D64/60; H10D64/64; H10D64/647
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
A silicon carbide field-effect transistor comprising a semiconductor substrate, a channel formation layer of silicon carbide formed above the substrate, source and drain regions provided in contact with the channel formation layer, a gate insulator disposed between the source and drain regions, and a gate electrode formed on the gate insulator, wherein a first contact between the channel formation layer and the drain region exhibits different electric characteristics from those of a second contact between the channel formation layer and the source region.
Claim 2
Dependent Claim
83 words
A silicon carbide field-effect transistor comprising a semiconductor substrate, a channel formation layer of silicon carbide formed above the substrate, source and drain regions provided in contact with the channel formation layer, a gate insulator disposed between the source and drain regions, and a gate electrode formed on the gate insulator, wherein a first contact between the channel formation layer and the drain region exhibits different electric characteristics from those of a second contact between the channel formation layer and the source region.
Claim 3
Dependent Claim
33 words
A silicon carbide field-effect transistor according to claim 1, wherein the source and drain regions are provided in the channel formation layer, and the gate insulator is formed on the channel formation layer.
Claim 4
Dependent Claim
31 words
A silicon carbide field-effect transistor according to claim 1, wherein the channel formation layer is formed on the drain region, and the source region is formed on the channel formation layer.
Claim 5
Dependent Claim
31 words
A silicon carbide field-effect transistor according to claim 1, wherein the channel formation layer is formed on the drain region, and the source region is provided in the channel formation layer.
Claim 6
Dependent Claim
43 words
A silicon carbide field-effect transistor according to claim 1, wherein the first contact is a p-n junction having excellent electric characteristics in the reverse direction thereof and the second contact is a p-n junction having excellent electric characteristics in the forward direction thereof.
Claim 7
Dependent Claim
43 words
A silicon carbide field-effect transistor according to claim 1, wherein the first contact is a p-n junction having excellent electric characteristics in the reverse direction thereof and the second contact is a Schottky junction having excellent electric characteristics in the forward direction thereof.
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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) | 1995-12-08 | 1996-06-08 | 1996-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-08 | 2000-06-08 | 2000-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-08 | 2004-06-08 | 2004-12-08 | $7700.00 | Window Closed / Lapsed |