Wafer scale and reliability investigation of thin HfO2·AlGaN/GaN MIS-HEMTs

A wafer scale investigation of AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) fabricated with a 4 in. Si CMOS compatible technology is presented in this paper. High performance AlGaN/GaN MIS gated HEMT (MIS-HEMT) and passivated HEMT (i-HEMT) were fabricated using thin HfO2 and CVD Si3N4 as the gate and passivation insulator, respectively. Gate and drain leakage currents as well as dynamic I-V trapping were significantly improved with the MIS-HEMT architecture with almost no trade-off to the on-state. Preliminary assessment of the device off-state reliability has been performed at elevated temperatures up to 310 °C.