Semiconductor device including normally-off type junction transistor and method of manufacturing the same

Abstract

In a junction FET of a normally-off type, a technique capable of achieving both of improvement of a blocking voltage and reduction of an ON resistance is provided. In a junction FET using silicon carbide as a substrate material, impurities are doped to a vicinity of a p-n junction between a gate region and a channel-formed region, the impurities having a conductive type which is reverse to that of impurities doped in the gate region and same as that of impurities doped in the channel-formed region. In this manner, an impurity profile of the p-n junction becomes abrupt, and further, an impurity concentration of a junction region forming the p-n junction with the gate region in the channel-formed region is higher than those of a center region in the channel-formed region and of an epitaxial layer.