Characteristics of Circular β-Ga 2 O 3 MOSFETs with High Breakdown Voltage (>1,000 V)

In this study, MOSFETs fabricated on Si-doped, MBE-grown β-Ga2O3 are demonstrated. A Si-doped Ga2O3 epitaxial layer was grown on a Fe-doped, semi-insulating 1.5 cm × 1 cm Ga2O3 substrate using molecular beam epitaxy (MBE). The fabricated devices are circular type MOSFETs with a gate length of 3 μm, a source-drain spacing of 20 μm, and a gate width of 523 μm. The device exhibited a good pinch-off characteristic, a high on-off drain current ratio of approximately 2.7×10, and a high breakdown voltage of 1,080 V, which demonstrates the potential of Ga2O3 for power device applications including electric vehicles, railways, and renewable energy.