Silicon carbide semiconductor device and method of manufacturing silicon carbide semiconductor device

Abstract

In forming an ohmic electrode on a back surface of an n-type SiC substrate, an n-type semiconductor region is formed in a surface layer of the back surface of an n-type epitaxial substrate by ion implantation. In this ion implantation, the impurity concentration of the n-type semiconductor region is a predetermined range and preferably a predetermined value or less, and an n-type impurity is implanted by acceleration energy of a predetermined range such that the n-type semiconductor region has a predetermined thickness or less. Thereafter, a nickel layer and a titanium layer are sequentially formed on the surface of the n-type semiconductor region, the nickel layer is heat treated to form a silicide, and the ohmic electrode formed from nickel silicide is formed. In this manner, a back surface electrode that has favorable properties can be formed while peeling of the back surface electrode can be suppressed.