A Study on the SBH(Schottky Barrier Height) of ICP(Inductively Coupled Plasma) Treated SiGe/Metal Contact

摘要

The effect of surface treatment of n-type SiGe using the inductively coupled plasma (ICP) was studied by current-voltage and x-ray photoemission spectroscopy measurements. The ICP treatment produced surface oxides and point defects at the surface of SiGe. The x-ray photoemission spectroscopy measurements showed that atomic ratio of Ge/Si was increased after the etching treatment. These results provide the evidence that Si vacancies were produced at the etched surface. Si vacancies acting as donor for electrons resulted in shift of Fermi level to near the conduction band. As a result, Fermi level could be pinned at such Si vacancies, leading to the remarkable reduction of Schottky barrier height and the reduced dependence of Schottky barrier height on metal work function.