Characteristics of Fluorine Implantation for HfO_2 Gate Dielectrics with High-Temperature Postdeposition Annealing

摘要

In this work, we describe the characteristics of silicon surface fluorine implantation (SSFI) for HfO_2 films with high-temperature postdeposition annealing. The thermal stability of HfO_2 gate dielectrics is much improved owing to the incorporation of fluorine into HfO_2 thin films. The gate leakage current of the SSFI HfO_2 films is about three orders less than that of samples without any fluorine implantation. In addition, improvements in stress-induced leakage current (SILC) and charge trapping characteristics are realized in the HfO_2 films with the SSFI. The incorporation of fluorine atoms into the HfO_2 films reduces not only interface dangling bonds but also bulk traps, which is responsible for the improvements in properties.