Single β-Ga2O3 nanowire back-gate field-effect transistor

Abstract In this work, a normally-on single-monocrystal β -Ga 2 O 3 nanowire (NW) back-gate field-effect transistor (FET) has been demonstrated by transferring metal-organic chemical vapor deposition-grown β -Ga 2 O 3 NWs on sapphire onto SiO 2 (300 nm)/ p + -Si substrate. When the gate voltage ( V G ) exceeds −14 V, the device is pinched off, with an on/off ratio greater than 10 8 and a drain leakage current density as low as ∼7.34 fA. The maximum field-effect carrier mobility for these n -doped single β -Ga 2 O 3 NW FETs reaches ∼62.2 cm 2 (V s) −1 . A prompt degradation in the on/off ratio for these β -Ga 2 O 3 NW back-gate FETs is observed as the operation temperature increased up to 400 K. With strong evidence, the temperature-dependent degradation in the performance is determined by the activation of self-trapped holes and intrinsic vacancy-related defects, both of which would lead to a rapid increase in the channel leakage current at high temperatures.