A semiconductor device is disclosed that includes a semiconductor substrate having
a first surface and a second surface and a first conductivity type and at least
one epitaxial layer on the first surface of the semiconductor substrate. The epitaxial
layer is formed of a material with a dissociation temperature below that of the
semiconductor substrate. A zone of increased carrier concentration is in the semiconductor
substrate and extends from the second surface of the semiconductor material toward
the first surface. A layer of metal is deposited on the second surface of the semiconductor
substrate and forms an ohmic contact at the interface of the metal and the zone
of increased carrier concentration.
