MOSFET, semiconductor device using the same and production process therefor

摘要

A MOSFET includes: a first conductivity type a semiconductor substrate having a trench formed in a surface area thereof, a gate electrode formed on the semiconductor substrate; and a trench gate electrode which is adjacent to the gate electrode and is buried in the trench, and which generates an output by AND logic in response to inputs to the gate electrode and the trench gate electrode, wherein an impurity concentration directly below the gate electrode is higher than an impurity concentration directly below the trench gate electrode.