Improvements of ozone surface treatment on the electrical characteristics and reliability in HfO2 gate stacks

Abstract

In this study, we improved the interfacial properties of high-kappa gate stacks with the surface treatment of ozonated water prior to deposition of hafnium oxide (HfO2). We demonstrated that the Ozone-oxide improved the electrical properties of the HfO2 gate stack interface in terms of its smoother interface, lower leakage current density, narrower hysteresis width, superior charge trapping effect, and reliability. From these experimental results, we believe that treatment with ozone is an efficient method for the preparation of high-quality interfaces between HfO2 and silicon surfaces.