Patent ID: 6238980
Filing Date: 2001-05-29
Classification: H01L

Abstract:
A method for manufacturing a silicon carbide MOS semiconductor device, comprising the steps of:laminating a first conductivity type drift layer comprising silicon carbide, on a silicon carbide substrate;forming a second conductivity type base region in a selected portion of a surface layer of said first conductivity type drift layer, using a first mask, said second conductivity type base region comprising mutually spaced portions;forming a first conductivity type source region in a selected portion of said second conductivity type base region, using a second mask;forming a gate electrode layer on a gate insulating film, over a surface of said second conductivity type base region that is interposed between said first conductivity type source region and an exposed surface portion of said first conductivity type drift layer;forming a source electrode in contact with surfaces of both of said first conductivity type source region and said second conductivity type base region; andforming a drain electrode on a rear surface of said silicon carbide substrate;wherein each of said first mask and said second mask used for forming said second conductivity type base region and said first conductivity type source region, respectively, comprises a polysilicon film or an oxide film thereof, said second conductivity type base region and said first conductivity type source region being positioned with respect to each other, utilizing a difference in the position of edges of said first and second masks due to oxidation or removal of the oxide film.