Patent ID: 8658503

Claim:
A method of fabricating a semiconductor device comprising: forming a first silicon carbide layer of a first conductive type on a first main surface of a silicon carbide substrate; forming a first ion implantation mask formed of first mask materials and a second mask material, above a top surface of the first silicon carbide layer, the first mask materials including two regions which are substantially perpendicular to the first main surface, and the second mask material being filled between the first mask materials; ion-implanting an impurity of a second conductive type into the first silicon carbide layer using the first ion implantation mask to form first silicon carbide regions; forming a second ion implantation mask formed of the first mask materials, by removing the second mask material, and ion-implanting an impurity of the second conductive type into the first silicon carbide layer using the second ion implantation mask to form a fourth silicon carbide region between the facing first silicon carbide regions with the first silicon carbide layer therebetween; forming a third ion implantation mask above the top surface of the first silicon carbide layer and ion-implanting an impurity of the first conductive type into the first silicon carbide layer using the third ion implantation mask to form second silicon carbide regions; forming a fourth ion implantation mask above the top surface of the first silicon carbide layer and ion-implanting an impurity of the second conductive type into the first silicon carbide layer using the fourth ion implantation mask to form third silicon carbide regions; forming a gate insulating film continuously on surfaces of the first silicon carbide regions, the first silicon carbide layer, and the fourth silicon carbide region; forming a gate electrode on the gate insulating film; forming an interlayer insulating film on the gate electrode; forming a first electrode which is electrically connected to the second silicon carbide regions and the third silicon carbide regions; and forming a second electrode on a second main surface of the silicon carbide substrate.