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 500degC anneal, a high kappa value of 14.5, a low leakage current density of ~10^-9 A/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 252 mA/mm and 143 mS/mm, respectively, of 1 mum-gate length.