Characteristics of the HfO2 Thin Films Grown by Remote Plasma Atomic Layer Deposition Method on the Plasma Oxidized Si Substrate

Abstract

We investigated the electrical and physical characteristics of HfO2/SiO2/Si structure grown by remote plasma atomic layer deposition (RPALD) method. The surface preparation of Si (100) substrate was performed on HF-cleaned Si substrate by remote plasma oxidation (RPO) process and yielded about 0.5-nm-thick SiO2 layer. HfO2 films were deposited on both HF-cleaned and RPO-treated Si substrates by the RPALD method, respectively. Results show that the RPO-treated substrate effectively suppressed the diffusion of oxygen or/and silicon into the film during film deposition. Therefore, the RPO-treated samples have thinner initial Hf silicate layers than those without RPO treated substrate. And we have also observed a decreasing of the hysteresis and effective charge density (Qeff) as well as an improvement of the equivalent oxide thickness (EOT) in RPO treated samples.