Patent ID: 7335928

Claim:
A silicon carbide semiconductor device having a vertical field effect transistor, said field effect transistor comprising: a substrate of a first conductivity type having a low concentration of impurity, said substrate constituting a semiconductor substrate, the band gap of which is 2.0 eV or more; a drain electrode formed over one surface of said substrate; an epitaxial layer of the first conductivity type formed on an opposite surface of said substrate and having a lower resistance than said substrate; a source region of the first conductivity type formed along the opposite surface of said semiconductor substrate; a plurality of first grooves formed from the opposite surface of said semiconductor substrate; a first gate region of a second conductivity type formed along said first grooves; a source contact layer formed on an opposite surface side of said source region; a source electrode in ohmic contact with said source contact layer; a second groove formed from the opposite surface of said semiconductor substrate; a second gate region of the second conductivity type formed along said second groove; a gate electrode in ohmic contact with a draw-out layer in said second gate region through a gate contact layer; and a metal conductor in ohmic contact with a contact layer in said gate region on the bottom of each said first groove independently of said gate electrode.