High performance Ga2O3(Gd2O3)/Ge MOS devices without interfacial layers

Excellent electrical performances have been demonstrated for the MOSCAPs and MOSFETs using Ga
₂
O
₃
(Gd
₂
O
₃
) gate dielectrics deposited at room temperature on Ge(100) without employing any interfacial layers. In this work, we report a very low interfacial density of state (D
_it
) of ~2times10
¹¹
cm
^-2
eV
^-1
, a low leakage current density (J
_g
) of ~10
^-9
A/cm
²
, well-behaved capacitance-voltage (C-V) characteristics including an excellent quasi-static C-V curve along with a high efficiency of 80% for the Fermi-level movement near the mid-gap. In addition, a high saturation drain current and a high transconductance of 496 muA/mum and 178 muS/mum, respectively, for the 1 mum-gate-length device have been obtained as well.