Epitaxial Growth of Iron-Silicide Nanodots on Si Substrates Using Ultrathin SiO_2 Film Technique and Their Physical Properties

摘要

We developed a formation technique for iron silicide nanodots (NDs) on Si substrates using ultrathin SiO_2 film technique. In this technique, the NDs were epitaxially grown on Si substrates with ultrahigh density (＞10~(12) cm~(-2)). Furthermore, the crystal structures in formed NDs are controllable even though iron silicide has complicated phase diagram. The optical properties of semiconductor β-FeSi_2 NDs were measured on nanometer scale, which clarified their optical absorption band edges. Magnetic properties of formed Fe_3Si NDs were investigated, which indicated the magnetic dipole interactions in ultrahigh density ND system. This strongly depended on ND morphology demonstrating magnetic properties could be controlled by manipulating ND formation.