High-Voltage AlGaN/GaN High-Electron-Mobility Transistors Using Thermal Oxidation for NiOx Passivation

  • Kim, Minki (Dept. of Electrical Engineering and Computer Science, Seoul National University, Power Control Device Lab., Electronics and Telecommunications Research Institute) ;
  • Seok, Ogyun (Dept. of Electrical Engineering and Computer Science, Seoul National University) ;
  • Han, Min-Koo (Dept. of Electrical Engineering and Computer Science, Seoul National University) ;
  • Ha, Min-Woo (Korea Electronics Technology Institute)
  • Received : 2012.12.21
  • Accepted : 2013.04.03
  • Published : 2013.09.01


We proposed AlGaN/GaN high-electron-mobility transistors (HEMTs) using thermal oxidation for NiOx passivation. Auger electron spectroscopy, secondary ion mass spectroscopy, and pulsed I-V were used to study oxidation features. The oxidation process diffused Ni and O into the AlGaN barrier and formed NiOx on the surface. The breakdown voltage of the proposed device was 1520 V while that of the conventional device was 300 V. The gate leakage current of the proposed device was 3.5 ${\mu}A/mm$ and that of the conventional device was 1116.7 ${\mu}A/mm$. The conventional device exhibited similar current in the gate-and-drain-pulsed I-V and its drain-pulsed counterpart. The gate-and-drain-pulsed current of the proposed device was about 56 % of the drain-pulsed current. This indicated that the oxidation process may form deep states having a low emission current, which then suppresses the leakage current. Our results suggest that the proposed process is suitable for achieving high breakdown voltages in the GaN-based devices.


Supported by : KETEP


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