ALD grown polycrystalline HfO2 dielectric layer on (−2 0 1) β-Ga2O3 for MOS capacitors

Polycrystalline HfO2 dielectrics grown on (−2 0 1) beta-gallium oxide (β-Ga2O3) using high temperature ALD process is investigated. A low capacitance–voltage (C-V) hysteresis of <60 mV is obtained, and the high quality interface is verified via the temperature-dependent C-V characterizations, showing low interface trap density (Dit < 1.3 × 1012 cm−2eV−1) distributions over the extended energy range. The proposed polycrystalline HfO2/(−2 0 1) β-Ga2O3 MOS structure can be an attractive candidate for β-Ga2O3 based MOSFET devices.