Method of manufacture of a silicon carbide MOSFET including a masking with a tapered shape and implanting ions at an angle

A method of manufacturing a silicon carbide (SiC) vertical MOSFET, the method comprising:

• forming an SiO2 mask on a surface of an epitaxial layer of SiC, the SiO2 mask having a tapered shape in cross-section, with side surfaces forming an angle with respect to a normal to the surface of the epitaxial layer of SiC in a range from 25° to 45°;
• implanting first ions into the epitaxial layer of SiC through the surface, using the SiO2 mask as an ion implantation mask, to produce a base region having a first conductivity type in the epitaxial layer of SiC;
• and
• implanting second ions into the epitaxial layer of SiC through the surface, using the SiO2 mask as an ion implantation mask, to produce a source region having a second conductivity type, opposite the first conductivity type, within the base region, so that at least the base region has an interface forming an angle with respect to the normal to the surface in a range from 30° to 60°.