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

Abstract

We report an enhanced field-effect mobility (> 250 cm2·V-1·s-1) in GaN MOSFETs. High mobility was achieved by reducing the oxidation of the GaN surface that was a major factor affecting channel mobility in GaN MOSFETs. Among various gate oxide deposition methods, mist CVD using O3 suppressed GaN surface oxidation. The best field-effect mobility was observed using mist CVD-deposited gate oxides, achieving a peak mobility of 266 cm2·V-1·s-1 with a high threshold voltage of 4.8 V.