High breakdown voltage normally off Ga2O3 transistors on silicon substrates using GaN buffer

Normally off beta-phase gallium oxide (β-Ga2O3) metal-oxide field-effect transistors (MOSFETs) on GaN-on-Si substrates were fabricated with a threshold voltage (VTH) of 3 V. β-Ga2O3 thin films were deposited using pulsed laser deposition. The device demonstrated an excellent breakdown voltage of ∼540 V at VGS = 0 V and an extremely low gate leakage current of ∼10−7 mA/mm. Additionally, it exhibited a low subthreshold swing (SS) of ∼167 mV/dec and a current on/off ratio of ∼106. The growth and fabrication of β-Ga2O3 MOSFETs on GaN-on-Si substrates are significant for high performance and their monolithic integration with GaN devices in future power-integrated circuits.