Effects of various surface treatments on gate leakage, subthreshold slope, and current collapse in AlGaN/GaN high-electron-mobility transistors

The reduction in the gate leakage current and the improvement in subthreshold characteristics and current collapse in AlGaN/GaN high-electron-mobility transistors (HEMTs) with various surface treatments were investigated. We applied wet treatment, digital etching (O-2 or N2O), or plasma treatment (CF4 or SF6) before SiNx passivation. Among these treatments, SF6 plasma treatment suppressed gate leakage current, reduced subthreshold slope, and improved pulsed current-voltage (I-V) characteristics most effectively. (C) 2014 The Japan Society of Applied Physics