Molecular dynamics simulations of solid-phase epitaxial growth in silicon

Abstract

Molecular dynamics (MD) simulations of solid-phase epitaxial growth of (0 0 1)silicon has already been performed in the literature in order to investigate the atomistic structure of the interface, the processes at the interface and the growth rate. For this purpose MD cells with about 10 3 Si atoms were used. In this paper, the topological structure of the amorphous Si/(0 0 1)Si interface and the growth rate are investigated by classical MD simulations based on the Stillinger–Weber potential using larger MD cells (about 5000 and 50,000 Si atoms). Especially, the dependence of the results on the size of the MD cell is studied. The a-Si/(0 0 1)Si system is prepared by melting and quenching the Si of one half of the initial (0 0 1)Si MD cell followed by a temperature treatment for a few nanoseconds. The growth rates are determined for different temperatures (800–1000 K), where the temperature dependence can be described by one activation energy. The topological structure of the interface is studied using a special procedure. The results depend remarkably on the size of the MD cell. Only by using the large MD cell it is possible to obtain a stationary interface which explains the large measured roughness of about 8 Å.