A Cluster Approach for the Modeling of the Layer-by-Layer Growth of Silicon Carbide Polytypes

Abstract

A cluster approach has been designed in order to confirm the physical bases of a previously presented dynamical model for chemical vapor deposition-chemical vapor infiltration S i c growth (Vignoles, G. L. J. Cryst. Growth 1992, 118,430). The clusters consist of two or three Si-C bilayers; the relaxation of the bond lengths in the upper bilayer of the clusters simulates the impingement of a new bilayer on the crystal surface. The quantities relevant to the model (energies and optimized geometries) have been calculated at the semiempirical level. The use of regular series of clusters allowed us to obtain extrapolated values for infinite surfaces. Qualitative agreement has been obtained between the cluster calculations and the assumptions made for the dynamical model.