In this work, we demonstrated a low current collapse normally on Al2O3/AlGaN/GaN MIS-HEMT with in situ H-radical surface treatment on AlGaN. The in situ atomic pretreatment was performed in a specially designed chamber prior to the thermal ALD-Al2O3 deposition, which improved the Al2O3/AlGaN interface with Dit of ~2 × 1012 cm−2 eV−1, and thus effectively reduced the current collapse and the dynamic Ron degradation. The devices showed good electrical performance with low Vth hysteresis and peak trans-conductance of 107 mS/mm. Additionally, when the devices operated under 25 °C pulse-mode stress measurement with VDS,Q = 40 V (period of 1 ms, pulse width of 1 μs), the dynamic Ron increase of ~14.1% was achieved.
