Epitaxial multilayers of <i>β</i>-FeSi2 nanodots/Si for Si-based nanostructured electronic materials

Abstract

Epitaxial growth method for multilayered structures of ultrasmall β-FeSi2 nanodots (NDs)/Si was developed as a Si-based material for thermoelectric or optical devices by applying our ultrathin SiO2 film technique. In this technique, strain-relaxed β-FeSi2 NDs were epitaxially grown with high density. For the formation of multilayered structures, Si growth on these β-FeSi2 NDs was carefully investigated. Si grew epitaxially on the NDs in three-dimension because of the lattice mismatch strain with the underlying NDs. As a result of three-dimensional Si growth, thicker Si (&amp;gt;20 monolayer) was needed to completely cover the NDs. The authors demonstrated that strain-relaxed β-FeSi2 NDs and the Si covering are two important factors for the formation of multilayered structures of β-FeSi2 NDs/Si.