Silicon carbide semiconductor device and power converter

Abstract

Fluctuations in device characteristics are suppressed by suppressing local occurrences of a large current through a body diode of a field-effect transistor. A silicon carbide semiconductor device includes a silicon carbide semiconductor substrate, a semiconductor layer formed on the upper surface of the silicon carbide semiconductor substrate, and a backside electrode formed on the lower surface of the silicon carbide semiconductor substrate. A region in which electric resistivity takes a first value is regarded as a first resistance region, and a region where the electric resistivity takes a second value greater than the first value is regarded as a second resistance region. The second resistance region extends across a region boundary, i.e., the boundary between the active region and the termination region, in plan view.