Discrete and Half Bridge Module using GaN HFETs for High Temperature Applications more than 200°C

AlGaN/GaN HFETs are expected to be a good candidates for power switching application at high temperatures. We optimized the fabrication process of the AlGaN/GaN HFET. A low specific on-state resistance of 6.3 mOmegacm² and a large breakdown voltage of 600 V were achieved at 225degC. We also designed and fabricated a half bridge module using the AlGaN/GaN HFETs and SiC SBDs. Switching characteristics of the AlGaN/GaN HFET were investigated. The small turn-on delay of 7.2 nsec, which is 1/10 of Si MOSFET, was observed. The switching characteristics of the HFET showed no significant degradation up to 225degC.