Improved operation stability of Al2O3/AlGaN/GaN MOS high-electron-mobility transistors grown on GaN substrates

This paper presents electrical characterization of Al2O3/AlGaN/GaN metal-oxide-semiconductor (MOS) high-electron-mobility transistors (HEMTs) grown on GaN substrates. The postmetallization annealing (PMA) at 300 degrees C achieved effective reduction of electronic states at the Al2O3/AlGaN interface, leading to improved gate controllability and current linearity of the MOS HEMTs. The MOS HEMT with PMA showed a subthreshold slope of 68 mV dec(-1). In addition, excellent operation stability of the MOS HEMT was observed at high temperatures. Even at 150 degrees C, the HEMT showed low leakage current of 1.5 x 10(-9) A mm(-1) and a threshold voltage drift of only 0.25 V from its room temperature value. (c) 2019 The Japan Society of Applied Physics