Effect of Buffer Layer for HfO2 Gate Dielectrics Grown by Remote Plasma Atomic Layer Deposition

Abstract

Three different buffer layers on a Si substrate were grown to investigate the interfacial layer effect during deposition and thermal annealing. The three different buffer layers were the very thin , remote plasma nitridation (RPN)-treated , and RPN-treated films. films were then grown on these three different buffer layers by a remote plasma atomic layer deposition method. The films with RPN-treated buffer layers retarded silicate formation or growth of an interfacial layer more effectively than those without RPN treatment. The films with an RPN-treated buffer layer showed the lowest effective oxide thickness and those with an RPN-treated buffer layer exhibited low leakage current density. The effective fixed-oxide charge density of the film with an RPN-treated buffer layer showed the lowest value of compared to the other films. As the annealing temperature increased, the flatband voltage for the films was shifted and became close to the ideal . The interface stability of with a nitrided buffer layer formed by RPN treatments resulted in the improvement of the electrical properties of films.