US Patent 8035112 SIC power DMOSFET with self-aligned source contact

An intermediate product in the fabrication of a MOSFET, including a silicon carbide wafer having a substrate and a drift layer on said substrate, said drift layer having a plurality of source regions formed adjacent an upper surface thereof; a first oxide layer on said upper surface of said drift layer; a plurality of polysilicon gates above said first oxide layer, said plurality of polysilicon gates including a first gate adjacent a first of said source regions; an oxide layer over said first source region of greater thickness than said first oxide layer; and, an oxide layer over said first gate of substantially greater thickness than said oxide layer over said first source region.