Improved electrical properties of Pt/HfO2/Ge using in situ water vapor treatment and atomic layer deposition

Abstract

The effects of water vapor treatment (WVT) on a Ge substrate were investigated in order to understand the improved electrical properties of Pt/HfO2/Ge metal-oxide-semiconductor (MOS) capacitors. The WVT and HfO2 deposition were performed in situ using an atomic layer deposition technique to avoid air exposure. As a result, the WVT on cleaned Ge substrates reduced the native oxide effectively and enhanced the initial growth of the HfO2 film. The improved interface qualities with WVT enhanced Ge-based device performance through a smoother capacitance-voltage curve, less increase in the inversion capacitance, and lower density of interface states.