Metal-oxide-semiconductor devices with UHV-Ga 2 O 3 (Gd 2 O 3 ) on Ge(100)

Ultra-high vacuum (UHV)-deposited high Ga 2 O 3 (Gd 2 O 3 ) was proved to passivate Ge effectively, as evidenced by comprehensive investigations including structural, chemical, and electrical analyses. The Ga 2 O 3 (Gd 2 O 3 )/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 −9 A/cm 2 with a Fowler-Nordheim tunneling behavior, and well-behaved C-V characteristics are achieved. Furthermore, Ge self-aligned pMOSFETs with Al 2 O 3 / Ga 2 O 3 (Gd 2 O 3 ) 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.