Interaction of iron atoms with the silicon surface coated with a native oxide layer

Abstract

The solid-phase epitaxy of iron silicide on the Si(111) surface coated with a native oxide layer is studied by high-resolution photoelectron spectroscopy using synchrotron radiation and by atomic force microscopy. The iron deposition dose changes up to 1 nm, and the annealing temperature changes up to 500°C. At room temperature, the native oxide layer is shown to be impermeable to Fe atoms and an iron film grows on the sample surface. An increase in the annealing temperature to ∼100°C results in a change in the film morphology, increasing its heterogeneity. As the annealing temperature increases to ∼250°C, Fe and Si atoms diffuse through the oxide layer and undergo a solid-phase reaction. As a result, stable iron monosilicide ɛ-FeSi forms.