Patent ID: 9490319
Filing Date: 2016-11-08
CPC Classification: H01L

Claim Text:
1. A silicon carbide semiconductor device, comprising: a silicon carbide layer having a first main surface and a second main surface opposite to said first main surface, said silicon carbide layer including said second main surface of said silicon carbide layer being provided with one or more trenches, said one or more trenches having a sidewall surface passing through said third layer and said second layer to reach said first layer and a bottom portion located in said first layer, said sidewall surface having a first sidewall surface and a second sidewall surface which are opposed to each other in a cross-sectional view, said one or more trenches further having, in a cross-sectional view, a first corner portion which is an intersection between said first sidewall surface and said bottom portion and a second corner portion which is an intersection between said second sidewall surface and said bottom portion, said first layer having one or more second-conductivity-type regions located on a side of said first main surface relative to said bottom portion and having said second conductivity type, in a cross-sectional view, said one or more second-conductivity-type regions being arranged to intersect with a line which passes through any of said first corner portion of said one or more trenches and said second corner portion of said one or more trenches and is in parallel to a <0001> direction of a silicon carbide crystal forming said silicon carbide layer, and a ratio calculated by dividing SP by ST being not lower than 20% and not higher than 130%, where ST represents a total area of said one or more trenches in a boundary surface between said first layer and said second layer and SP represents a total area of said one or more second-conductivity-type regions in a plan view, wherein said one or more second-conductivity-type regions being distant from said bottom portion, below said first corner portion, and below said second corner portion of one of said one or more trenches.