Vertical-type metal insulator semiconductor field effect transistor device, and production method for manufacturing such transistor device

Abstract

In a vertical-type metal insulator field effect transistor device having a first conductivity type drain region layer, a plurality of second conductivity type base regions are produced and arranged in the first conductivity type drain region layer, and a first conductivity type source region is produced in each of the second conductivity type base regions. Both a gate insulating layer and a gate electrode layer are formed on the first conductivity type drain region layer such that a plurality of unit transistor cells are produced in conjunction with the second conductivity type base regions and the first conductivity type source regions, and each of the unit transistor cells includes respective span portions of the gate insulating layer and the gate electrode layer, which bridge a space between the first conductivity type source regions formed in two adjacent second conductivity base regions. A buried-insulator region is produced in the first conductivity type drain region layer beneath each of the portions of the gate electrode layer.