Axial orientation of molecular-beam-epitaxy-grown FeSi/Ge hybrid structures and its degradation

Maeda, Yoshihito; Jonishi, Takafumi*; Narumi, Kazumasa; Ando, Yuichiro*; Ueda, Koji*; Kumano, Mamoru*; Sado, Taizo*; Miyao, Masanobu*

Applied Physics Letters, 91(17), p.171910_1 - 171910_3, 2007/10

https://doi.org/10.1063/1.2801705

The axial orientation of molecular-beam-epitaxy (MBE)-grown FeSi(111)/Ge(111) hybrid structures was investigated by Rutherford backscattering spectroscopy. We confirmed that during MBE above 300C, the interdiffusion of Fe and Ge atoms results in a composition change and the epitaxial growth of FeGe in FeSi. Low-temperature (200 C) MBE can realize fully ordered DO-FeSi with highly axial orientation [minimum yield ()=2.2%]. Postannealing above 400 C results in a composition change and the degradation of axial orientation in the off-stoichiometric FeSi. The significance of stoichiometry with regard to thermal stability and the interfacial quality of FeSi(111)/Ge(111) hybrid structures was also discussed.