Effects of source materials on fabrication of β-FeSi₂ thin films by RDE method

Abstract

The reactive deposition epitaxial (RDE) growth method has been employed extensively in the β-FeSi2 thin film growth. It has been already clarified also that the Fe/Si ratio of source materials affects on the quality of deposited β-FeSi2 thin films by ion beam sputter deposition under high-vacuum condition. On the other hand, to provide methods capable of depositing a high-quality β-FeSi2 thin films inexpensively are important as well. In this study, we used a conventional vacuum deposition system and a few different kinds of iron silicides of Fe2Si, α-FeSi2 and ε-FeSi, which each contains Si, as the source materials in the RDE growth. We found that the depositing Fe2Si onto heated Si substrate helps improving the film flatness and the electric properties of the obtained β-FeSi2 thin films compared to that of Fe-deposited films, even at the relatively low vacuum depositing.