FIELD-EFFECT SEMICONDUCTOR DEVICE AND FABRICATION METHOD THEREOF

摘要

A buried gate region, a buried gate contact region and a gate contact region are provided on an SiC substrate. Thereby, a depletion layer expands in the channel region, and a high withstand voltage is attained in the normally off state. By applying a voltage of the built-in voltage or less to a gate, the depletion layer in the channel region becomes narrower and an ON-state resistance becomes low. Furthermore, when a voltage of the built-in voltage or more is applied to the gate, holes are injected from the gate so as to cause the conductivity modulation, and the ON-state resistance becomes further low.