SEMICONDUCTOR FIELD EFFECT TRANSISTOR AND METHOD FOR FABRICATING THE SAME

摘要

A gallium nitride based field effect transistor having good current hysteresis characteristics in which forward gate leakage can be reduced. In a gallium nitride-based field effect transistor (100) having a gate insulation film (108), a part or all of a material constituting the gate insulation film (108) is a dielectric material having a dielectric constant of 9-22, and a semiconductor crystal layer A (104) in contact with the gate insulation film (108) and a semiconductor crystal layer B (103) in the vicinity of the semiconductor crystal layer A (104) and having a larger electron affinity than the semiconductor crystal layer A (104) constitute a hetero junction. A hafnium oxide such as HfO<SUB>2</SUB>, HfAlO, HfAlON or HfSiO is preferably contained, at least partially, in the material constituting the gate insulation film (108).