Misfet

Abstract

P-type active region; n-type source/drain regionsand; gate insulating filmmade of a thermal oxide film; gate electrode; source/drain electrodesand, are provided over a p-type SiC substrate. In the active region, p-type heavily doped layers, which are thin enough to create a quantum effect, and thick undoped layersare alternately stacked. When carriers flow, scattering of impurity ions in the active region is reduced, and the channel mobility increases. In the OFF state, a depletion layer expands throughout the active region, and the breakdown voltage increases. As a result of reduction in charges trapped in the gate insulating film or near the interface between the gate insulating film and the active region, the channel mobility further increases.