Large periphery AlInN/AlN/GaN metal-oxide-semiconductor heterostructure field-effect transistors on sapphire substrate

We report on the study of multi-gate AlInN/InN/GaN metal-oxide semiconductor field-effect transistors (MOSHFET) over a sapphire substrate with gate widths varying from 0.25 mm-5 mm. A high saturation output current of similar to 1.3 A and a maximum extrinsic transconductance of 210 mS are demonstrated for the 5 mm wide device with a gate length of 1.8 mu m and a source-drain spacing of 12 mu m. The maximum saturation output current and the maximum extrinsic transconductance appear to scale nearly linearly with the gate width up to 1 mm, beyond which joule heating dominates. These results show the potential of these MOSHFETs for high-voltage and high power operation.