Work

Threshold Voltage Hysteresis and Gate Leakage in AlGaN/GaN HEMTs

Year: 2025

Type: article

Abstract: Temperature-dependent threshold voltage ($V_{\mathrm {TH}}$) hysteresis and gate leakage current are characterized in commercial AlGaN/GaN high electron mobility transistors (HEMTs). Significant peaks in$V_{\mathrm {TH}}$hysteresis are observed at$220 \; \pm \; 10$K. Gate leakage current increases with increasing temperature for as-processed devices and devices irradiated with 1.8-MeV protons atoff-state bias, due to Mott hopping. In contrast, gate leakage current for devices irradiated or stressed aton-bias increases strongly with decreasing temperature below 200 K. The increased gate leakage at low temperatures and large negative bias inon-bias stressed and/or irradiated devices is attributed primarily to trap-assisted tunneling through oxygen impurities (ON) in AlGaN. Dehydrogenation of ON-H impurity centers during stress and/oron-bias irradiation evidently plays a key role in enhanced cryogenic gate leakage at large negative bias in these devices.

Source: IEEE Transactions on Nuclear Science

DOI: 10.1109/tns.2025.3551268