The thermodynamic properties and interfacial characteristics of Hf O2 thin films that were deposited by the direct plasma atomic layer deposition (DPALD) method are investigated. The as-deposited Hf O2 films that were deposited by the DPALD method show crystallization of the Hf O2 layers, which initiates at approximately the 35th cycle (about 2.8 nm) of the DPALD process. Medium-energy ion scattering analysis reveals that the direct O2 plasma causes a compositional change in the interfacial layer as the process progresses. With an increase in the number of process cycles, the Si content decreases and the O content increases at that position, so that the Hf O2 -like Hf-silicate layer is formed on top of the interfacial layer. The enhanced physical reactivity of the oxygen ions in the direct plasma and the Hf-silicate layer may be the driving forces that accelerate the early crystallization of the Hf O2 layer in the DPALD process in the as-deposited state.
Bibliographical noteFunding Information:
This study was supported by the National Program for Tera-level Nano-devices of the Ministry of Science and Technology as one of the 21st Century Frontier Programs.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)