FIELD EFFECT TRANSISTOR AND METHOD FOR MANUFACTURING SAME

摘要

Disclosed is a group III nitride semiconductor field effect transistor having excellent operation stability which is able to be manufactured at high yield. Specifically disclosed is an HJFET (100) comprising a group III nitride semiconductor layer structure including a heterojunction between a GaN channel layer (112) and an AlGaN electron supply layer (113), a source electrode (101) and a drain electrode (103) formed separately from each other on the group III nitride semiconductor layer structure, and a gate electrode (102) arranged between the source electrode (101) and the drain electrode (103). An SiN film (121) is provided on the group III nitride semiconductor layer structure in a region between the gate electrode (102) and the drain electrode (103). At the interface between the SiN film (121) and the AlGaN electron supply layer (113), the impurity concentration in the AlGaN electron supply layer (113) is not more than 1E17 atoms/cm<SUP>3</SUP>.