Abstract
YGeO x formed by thermal oxidation of Y/Ge structure was confirmed by X-ray photoelectron spectroscopy (XPS) and its eligibility as the passivation layer for Ge MOS devices was explored in this work. Because of the thermal oxidation nature of the process that effectively suppresses dielectric structural defects and incorporates sufficient Y atoms at the interface to well passivate the dangling bonds on Ge surface; the YGeO x enjoys a small amount of oxide traps and a low interface trap density (D it ) of 2.1 × 10 11 cm -2 eV -1 . In addition, the thermally grown YGeO x demonstrates a relatively high dielectric constant of 10.8 as compared to GeO 2 , tiny frequency dispersion in capacitance-voltage (C-V) characteristics, low leakage current of 3.1 × 10 -10 A/cm 2 at the effective electric field of 1 MV/cm, 13 mV flatband voltage (V fb ) shift for bias temperature instability measurement under the stress condition of 10 MV/cm for 8000 s at 85 C, these promising device characteristics attest to the eligibility of the YGeO x as the passivation layer for high-performance Ge MOS technology. ©2013 ElsevierB.V.Allrightsreserved.