Enhancement-mode Ga2O3 wrap-gate fin field-effect transistors on native (100) β-Ga2O3 substrate with high breakdown voltage

Sn-doped gallium oxide (Ga2O3) wrap-gate fin-array field-effect transistors (finFETs) were formed by top-down BCl3 plasma etching on a native semi-insulating Mg-doped (100) beta-Ga2O3 substrate. The fin channels have a triangular cross-section and are approximately 300 nm wide and 200 nm tall. FinFETs, with 20 nm Al2O3 gate dielectric and similar to 2 mu m wrap-gate, demonstrate normally-off operation with a threshold voltage between 0 and +1V during high-voltage operation. The I-ON/I-OFF ratio is greater than 10(5) and is mainly limited by high on-resistance that can be significantly improved. At V-G = 0, a finFET with 21 mu m gate-drain spacing achieved a three-terminal breakdown voltage exceeding 600V without a field-plate. (C) 2016 Author(s).