Heteroepitaxy of β-FeSi₂ on unstrained and strained Si(100) surfaces

Abstract

We have investigated factors influencing the heteroepitaxial growth of semiconducting β-FeSi2 on both unstrained and strained Si(100) surfaces under ultrahigh vacuum conditions using low energy electron diffraction, x-ray photoelectron spectroscopy, and scanning electron microscopy. We show that epitaxy and clear LEED patterns may be obtained by forming a template layer of FeSi2 followed by additional codeposition of reactants upon the template layer. Further improvement in the quality of the silicide layer is achieved by employing strained Si substrates. The dependence of the epitaxial silicide domain size on the lattice mismatch between the silicon substrate and the silicide layer is demonstrated.