SEMICONDUCTOR DEVICE HAVING SCHOTTKY JUNCTION ELECTRODE

摘要

A GaN semiconductor device improved in the heat resistance of a Schottky junction electrode and excellent in power performance and reliability. A semiconductor device having a Schottky gate electrode (17) in contact with an AlGaN electron supply layer (14), wherein the gate electrode (17) has a laminate structure consisting of a first metal layer (171) formed of any one of Ni, Pt, Pd, a second metal layer (172) formed of any one of Mo, Pt, W, Ti, Ta, MoSi, PtSi, WSi, TiSi, TaSi, MoN, WN, TiN, TaN, and a third metal layer formed of any one of Au, Cu, Al, Pt. The second metal layer, consisting of a material having a high melting point, acts as a barrier against the mutual diffusion between a first-metal-layer metal and a third-metal-layer metal to restrict gate characteristics deterioration due to a high-temperature operation. The first-metal-layer metal in contact with the AlGaN electron supply layer (14) has a large work function to thereby provide a high Schottky barrier and hence a good Schottky contact.