Patent ID: 9613809
Date: 2017-04-04
CPC Classifications: H01L

Claim:
1. A method of manufacturing a silicon carbide semiconductor device, comprising steps of: preparing a silicon carbide substrate having a first main surface and a second main surface opposite to each other; forming a first mask layer in contact with said first main surface of said silicon carbide substrate, said first mask layer including a first layer disposed in contact with said first main surface, an etching stop layer disposed in contact with said first layer and made of a material different from that for said first layer, and a second layer disposed in contact with a surface of said etching stop layer opposite to the surface in contact with said first layer; forming a recess in said first mask layer by etching said second layer and said etching stop layer; and forming a first impurity region having a first conductivity type in said silicon carbide substrate using said first mask layer with said recess, said first mask layer not including a metallic element, and further comprising a step of forming a second mask layer on said second main surface of said silicon carbide substrate, said second mask layer not including a metallic element.