Effects of post CF(4) plasma treatment on the HfO(2) thin film

Abstract

In this study, a novel approach was proposed to improve the characterization of HfO(2). Fluorine was incorporated by CF(4) plasma to improve the HfO(2) gate dielectric properties including leakage current, breakdown voltage and hysteresis. The hysteresis of capacitance-voltage characteristics can be reduced to approximately 10% hysteresis voltage for the samples with CF(4) plasma treatment. An inner-interface trapping model is presented to explain the hysteresis. The secondary-ion mass spectroscopy (SIMS) results show that there is a significant incorporation of fluorine (F) at the interface between the HfO(2) thin film and silicon substrate. The incorporation of F effectively suppressed leakage current and improved carrier trapping without an increase in interfacial layer thickness.