SILICON CARBIDE SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME
First Claim
1. A silicon carbide semiconductor device comprising a silicon carbide substrate having a main surface,said silicon carbide substrate includinga first impurity region that has a first conductivity type,a second impurity region that is provided on said first impurity region and that has a second conductivity type different from said first conductivity type, anda third impurity region that is provided on said second impurity region so as to be separated from said first impurity region, that forms said main surface, and that has said first conductivity type,said main surface of said silicon carbide substrate being provided with a trench,said trench having a side portion and a bottom portion, said side portion extending to said first impurity region through said third impurity region and said second impurity region, said bottom portion being located in said first impurity region,the silicon carbide semiconductor device further comprising:
- a gate insulating film in contact with a corner portion formed by said side portion and said main surface, said bottom portion, and said side portion;
a gate electrode in contact with said gate insulating film within said trench;
an interlayer insulating film in which an opening is formed to expose a portion of said gate electrode; and
a gate interconnection disposed in said opening and in contact with said gate electrode,when viewed in a cross section, said interlayer insulating film extending from above said third impurity region to above said gate electrode so as to cover said corner portion.
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Accused Products
Abstract
A silicon carbide semiconductor device includes a silicon carbide substrate, a gate insulating film, a gate electrode, an interlayer insulating film, and a gate interconnection. The silicon carbide substrate includes: a first impurity region; a second impurity region provided on the first impurity region; and a third impurity region provided on the second impurity region so as to be separated from the first impurity region. A trench has a side portion and a bottom portion, the side portion extending to the first impurity region through the third impurity region and the second impurity region, the bottom portion being located in the first impurity region. When viewed in across section, the interlayer insulating film extends from above the third impurity region to above the gate electrode so as to cover the corner portion.
17 Citations
22 Claims
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1. A silicon carbide semiconductor device comprising a silicon carbide substrate having a main surface,
said silicon carbide substrate including a first impurity region that has a first conductivity type, a second impurity region that is provided on said first impurity region and that has a second conductivity type different from said first conductivity type, and a third impurity region that is provided on said second impurity region so as to be separated from said first impurity region, that forms said main surface, and that has said first conductivity type, said main surface of said silicon carbide substrate being provided with a trench, said trench having a side portion and a bottom portion, said side portion extending to said first impurity region through said third impurity region and said second impurity region, said bottom portion being located in said first impurity region, the silicon carbide semiconductor device further comprising: -
a gate insulating film in contact with a corner portion formed by said side portion and said main surface, said bottom portion, and said side portion; a gate electrode in contact with said gate insulating film within said trench; an interlayer insulating film in which an opening is formed to expose a portion of said gate electrode; and a gate interconnection disposed in said opening and in contact with said gate electrode, when viewed in a cross section, said interlayer insulating film extending from above said third impurity region to above said gate electrode so as to cover said corner portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for manufacturing a silicon carbide semiconductor device, comprising the step of preparing a silicon carbide substrate having a main surface,
said silicon carbide substrate including a first impurity region that has a first conductivity type, a second impurity region that is provided on said first impurity region and that has a second conductivity type different from said first conductivity type, and a third impurity region that is provided on said second impurity region so as to be separated from said first impurity region, that forms said main surface, and that has said first conductivity type, said main surface of said silicon carbide substrate being provided with a trench, said trench having a side portion and a bottom. portion, said side portion extending to said first impurity region through said third impurity region and said second impurity region, said bottom portion being located, in said first impurity region, the method for manufacturing the silicon carbide semiconductor device further comprising the steps of: -
forming a gate insulating film in contact with a corner portion formed by said side portion and said main surface, said bottom portion, and said side portion; forming a gate electrode in contact with said gate insulating film within said trench; forming an interlayer insulating film in which an opening is formed to expose a portion of said gate electrode; and forming a gate interconnection disposed in said opening and in contact with said gate electrode, when viewed in a cross section, said interlayer insulating film extending from above said third impurity region to above said gate electrode so as to cover said corner portion. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification