SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME
First Claim
1. A semiconductor device comprising:
- a substrate made of silicon carbide and having a first trench and a second trench formed therein, said first trench having an opening at a side of one main surface, said second trench having an opening at the side of said main surface and being shallower than said first trench;
a gate insulating film disposed on and in contact with a wall surface of said first trench;
a gate electrode disposed on and in contact with said gate insulating film; and
a contact electrode disposed on and in contact with a wall surface of said second trench,said substrate includinga source region including said main surface of said substrate and said wall surface of said first trench,a body region making contact with said source region and including said wall surface of said first trench, anda drift region making contact with said body region and including said wall surface of said first trench,said first trench being formed to extend through said source region and said body region and reach said drift region,said second trench being formed to extend through said source region and reach said body region.
1 Assignment
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Accused Products
Abstract
A MOSFET includes: a substrate made of silicon carbide and having a first trench and a second trench formed therein, the first trench having an opening at the main surface side, the second trench having an opening at the main surface side and being shallower than the first trench; a gate insulating film; a gate electrode; and a source electrode disposed on and in contact with a wall surface of the second trench. The substrate includes a source region, a body region, and a drift region. The first trench is formed to extend through the source region and the body region and reach the drift region. The second trench is formed to extend through the source region and reach the body region.
25 Citations
10 Claims
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1. A semiconductor device comprising:
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a substrate made of silicon carbide and having a first trench and a second trench formed therein, said first trench having an opening at a side of one main surface, said second trench having an opening at the side of said main surface and being shallower than said first trench; a gate insulating film disposed on and in contact with a wall surface of said first trench; a gate electrode disposed on and in contact with said gate insulating film; and a contact electrode disposed on and in contact with a wall surface of said second trench, said substrate including a source region including said main surface of said substrate and said wall surface of said first trench, a body region making contact with said source region and including said wall surface of said first trench, and a drift region making contact with said body region and including said wall surface of said first trench, said first trench being formed to extend through said source region and said body region and reach said drift region, said second trench being formed to extend through said source region and reach said body region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for manufacturing a semiconductor device comprising the steps of:
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preparing a substrate made of silicon carbide and having a main surface; forming an active region in said substrate; forming a first trench having an opening at a side of said main surface of said substrate; forming a second trench having an opening at the side of said main surface of said substrate and shallower than said first trench; disposing a gate insulating film on and in contact with a wall surface of said first trench; disposing a gate electrode on and in contact with said gate insulating film; and disposing a contact electrode on and in contact with a wall surface of said second trench, in the step of forming said active region, a source region, a body region, and a drift region being formed, said source region including said main surface of said substrate, said body region making contact with said source region, said drift region making contact with said body region, in the step of forming said first trench, said first trench having said wall surface being formed to extend through said source region and said body region, reach said drift region, and expose said source region, said body region, and said drift region, in the step of forming said second trench, said second trench being formed to extend through said source region and reach said body region.
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Specification