Metal-oxide-semiconductor devices with UHV-Ga2O3(Gd2O3) on Ge(100)

Ultra-high vacuum (UHV)-deposited high Ga2O3(Gd2O3) was proved to passivate Ge effectively, as evidenced by comprehensive investigations including structural, chemical, and electrical analyses. The Ga2O3(Gd2O3)/Ge interface is revealed to be abrupt even being subjected to a 500°C anneal, a high κ value of 14.5, a low leakage current density of ∼10−9A/cm² with a Fowler-Nordheim tunneling behavior, and well-behaved C-V characteristics are achieved. Furthermore, Ge self-aligned pMOSFETs with Al2O3/ Ga2O3(Gd2O3) as the gate dielectrics have demonstrated a high drain current and a peak transconductance up to 252mA/mm and 143mS/mm, respectively, of 1µm-gate length.