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US5614749A
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Silicon carbide trench MOSFET
Assignee: Fuji Electric Co Ltd
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Filing: 1996-01-25
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Granted: 1997-03-25
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Expires: 2016-01-25
Abstract
Abstract A silicon carbide trench MOSFET is provided that includes a first conductivity type semiconductor substrate made of silicon carbide. A first conductivity type drift layer and a second conductivity type base layer, both made of silicon carbide, are sequentially formed by epitaxial growth on the semiconductor substrate. The first conductivity type drift layer has a lower impurity concentration than the semiconductor substrate. A first conductivity type source region is formed in a part of a surface layer of the second conductivity type base layer. A gate electrode is received through an insulating film, in a first trench extending from a surface of the first conductivity type source region to reach the first conductivity type drift layer. A Shottky electrode disposed on an inner surface of a second trench having a greater depth than the first trench.
Inventors
- 👤 Katsunori Ueno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 00:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/668; H10D12/00; H10D12/01; H10D12/031; H10D30/01; H10D30/021; H10D30/028; H10D30/0291; H10D30/0295; H10D30/0297; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D64/00; H10D64/20; H10D64/23; H10D64/251; H10D64/252; H10D64/2527; H10D64/256; H10D84/00; H10D84/101; H10D84/141; H10D84/146; H10D64/60; H10D64/64; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
157 words
A silicon carbide trench MOSFET comprising: a first conductivity type semiconductor substrate comprising silicon carbide; a first conductivity type drift layer and a second conductivity type base layer both comprising silicon carbide and sequentially formed by epitaxial growth on said semiconductor substrate, said first conductivity type drift layer having a lower impurity concentration than the semiconductor substrate; a first conductivity type source region formed in a part of a surface layer of said second conductivity type base layer; a first trench extending from a surface of said first conductivity type source region to reach said first conductivity type drift layer, a gate electrode formed in said first trench; an insulating film located between said gate electrode and said first conductivity type source region, said second conductivity type base layer and said first conductivity type drift layer; and a Shottky electrode disposed on an inner surface of a second trench having a greater depth than said first trench.
Claim 2
Dependent Claim
157 words
A silicon carbide trench MOSFET comprising: a first conductivity type semiconductor substrate comprising silicon carbide; a first conductivity type drift layer and a second conductivity type base layer both comprising silicon carbide and sequentially formed by epitaxial growth on said semiconductor substrate, said first conductivity type drift layer having a lower impurity concentration than the semiconductor substrate; a first conductivity type source region formed in a part of a surface layer of said second conductivity type base layer; a first trench extending from a surface of said first conductivity type source region to reach said first conductivity type drift layer, a gate electrode formed in said first trench; an insulating film located between said gate electrode and said first conductivity type source region, said second conductivity type base layer and said first conductivity type drift layer; and a Shottky electrode disposed on an inner surface of a second trench having a greater depth than said first trench.
Claim 3
Dependent Claim
31 words
A silicon carbide trench MOSFET as defined in claim 1, wherein said Shottky electrode is formed of a metal selected from the group consisting of Ti, Au, Pt, and Al-Ti alloy.
Claim 4
Dependent Claim
114 words
A silicon carbide trench MOSFET comprising: a first conductivity type semiconductor substrate comprising silicon carbide; a first conductivity type drift layer, a second conductivity type base layer and a first conductivity type source layer each comprising silicon carbide and sequentially formed by epitaxial growth on said semiconductor substrate, said first conductivity type drift layer having a lower impurity concentration than the semiconductor substrate; a first trench extending from a surface of said first conductivity type source layer to reach said first conductivity type drift layer; a gate electrode formed in said first trench; and a Shottky electrode disposed on an inner surface of a second trench having a greater depth than said first trench.
Claim 5
Dependent Claim
114 words
A silicon carbide trench MOSFET comprising: a first conductivity type semiconductor substrate comprising silicon carbide; a first conductivity type drift layer, a second conductivity type base layer and a first conductivity type source layer each comprising silicon carbide and sequentially formed by epitaxial growth on said semiconductor substrate, said first conductivity type drift layer having a lower impurity concentration than the semiconductor substrate; a first trench extending from a surface of said first conductivity type source layer to reach said first conductivity type drift layer; a gate electrode formed in said first trench; and a Shottky electrode disposed on an inner surface of a second trench having a greater depth than said first trench.
Claim 6
Dependent Claim
31 words
A silicon carbide trench MOSFET as defined in claim 3, wherein said Shottky electrode is formed of a metal selected from the group consisting of Ti, Au, Pt, and Al-Ti alloy.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-03-24 | 2000-09-23 | 2001-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-24 | 2004-09-23 | 2005-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-24 | 2008-09-23 | 2009-03-25 | $7700.00 | Window Closed / Lapsed |