Silicon carbide semiconductor device and method of manufacturing the same

A method of manufacturing a silicon carbide semiconductor device, comprising the steps of:

• preparing a silicon carbide substrate including a first layer having a first conductivity type, a second layer provided in said first layer and having a second conductivity type different from said first conductivity type, and a third layer provided on said second layer as being spaced apart from said first layer and having said first conductivity type;
• forming a trench having a sidewall portion reaching said second layer through said third layer and a bottom portion including an exposed surface of said second layer, by removing a part of said third layer and said second layer;
• forming an implanted region extending from said bottom portion of said trench to said first layer and having said first conductivity type by implanting an impurity of said first conductivity type into said exposed surface of said second layer, said implanted region being integrated with said first layer;
• forming a gate insulating film covering said sidewall portion and said bottom portion of said trench;
• and
• forming a gate electrode on said trench with said gate insulating film being interposed.

A method of manufacturing a silicon carbide semiconductor device, comprising the steps of:

• preparing a silicon carbide substrate including a first layer having a first conductivity type, two second layers provided at a distance from each other in said first layer and having a second conductivity type different from said first conductivity type, and a third layer provided on said first layer and said second layer and having said first conductivity type;
• exposing said first layer by providing an opening in said third layer from above a region between said two second layers and forming a trench having a sidewall portion reaching said second layer through said third layer and a bottom portion including an exposed surface of said first layer;
• forming a gate insulating film covering said sidewall portion and said bottom portion of said trench;
• and
• forming a gate electrode on said trench with said gate insulating film being interposed.