Growth of Sb-Doped β-FeSi2 Epitaxial Films and Optimization of Donor Activation Conditions

Abstract

Sb-doped β-FeSi2 epitaxial films on Si(111) were grown by molecular beam epitaxy to control an electron density of β-FeSi2. After an optimization of donor activation conditions in the Sb-doped β-FeSi2, the electron density of 6 × 1018 cm-3 at 300 K was achieved by thermal annealing in a N2 ambient. In the temperature dependence of carrier density, the n-type conduction was changed to p-type conduction at low temperatures in the film annealed at high temperature (600 °C). Raman spectra of the annealed films showed that both Fe and Si sites were substituted by the doped Sb in β-FeSi2 lattice.