Gallium oxide (Ga2O3) metal-semiconductor field-effect transistors on single-crystal β-Ga2O3 (010) substrates

We report a demonstration of single-crystal gallium oxide (Ga2O3) metal-semiconductor field-effect transistors (MESFETs). A Sn-doped Ga2O3 layer was grown on a semi-insulating beta-Ga2O3 (010) substrate by molecular-beam epitaxy. We fabricated a circular MESFET with a gate length of 4 mu m and a source-drain spacing of 20 mu m. The device showed an ideal transistor action represented by the drain current modulation due to the gate voltage (V-GS) swing. A complete drain current pinch-off characteristic was also obtained for VGS < -20 V, and the three-terminal off-state breakdown voltage was over 250 V. A low drain leakage current of 3 mu A at the off-state led to a high on/off drain current ratio of about 10000. These device characteristics obtained at the early stage indicate the great potential of Ga2O3-based electrical devices for future power device applications. (C) 2012 American Institute of Physics. [doi:10.1063/1.3674287]