Interfacial structure of Fe₃Si/FeSi₂ layered films deposited on si(111) at elevated substrate-temperatures

Influence of substrate-temperature on the interfacial structure of Fe ₃Si/FeSi₂ layered films deposited on a Si(111) substrate were studied. Fe₃Si/FeSi₂ films with sharp interfaces were grown at room substrate-temperature. At a substrate-temperature of 300 °C, interfaces between the Fe₃Si and FeSi₂ layers were obviously unsharpened, while the crystallinity of Fe₃Si was enhanced. The compositional periodic structure was barely unsharpened and it was nearly the same as that of the films deposited at room substrate-temperature. Epitaxial growth of Fe₃Si layers across FeSi₂ layers was carried out. This substrate-temperature is the upper limit at which the heterostructure formation takes place. At 400 °C, ε-FeSi was formed due to activated interdiffusion, and the structure of Fe₃Si changed partially from B2-type to DO₃-type.