Effect of nanoscale surface morphology on the phase stability of 3C-AlN films on Si(111)

Abstract

In this work, we report on the stabilization of 3C-AlN polytype by molecular-beam epitaxy (MBE) on 3C-SiC∕Si(111) pseudosubstrates. The main purpose of the present studies is to analyze the mechanisms forcing the epitaxy of the 3C-AlN at typical MBE conditions. The forces driving the cubic polytype formation have been considered including supersaturation, macroscopic stress, interfacial energy, and interface morphology. We conclude that the growth of 3C-AlN phase can be stabilized on the “rough” 3C-SiC(111) surface by the polytype replication due to the lateral character of the nucleation and the reduction in the total energy of the film provided by periodical undulations of the template surface.