Enhanced field-effect mobility (>250 cm²/V·s) in GaN MOSFETs with deposited gate oxides via mist CVD

We report an enhanced field-effect mobility (>250 cm 2 ·V −1 ·s −1 ) in GaN MOSFETs. High mobility was achieved by reducing the oxidation of the GaN surface, which was a major factor affecting channel mobility in GaN MOSFETs. Among various gate oxide deposition methods, mist CVD using O 3 suppressed GaN surface oxidation. The best field-effect mobility was observed using mist CVD-deposited gate oxides, achieving a peak mobility of 266 cm 2 ·V −1 ·s −1 with a high threshold voltage of 4.8 V.