Study of surface roughening of tensily strained Si_(1-x-y)Ge_xC_y films grown by ultra high vacuum-chemical vapor deposition

摘要

In this paper, we study the kinetics of carbon incorporation in Si_(1-x-y)Ge_xC_y/Si(0001), by ultra high vacuum-chemical vapor deposition. Layers were grown with a Ge content of 3% and substitutional C content up to 1.7%. All the layers were tensily strained. Using a simple model derived from the commonly accepted growth mechanism for silicon from SiH_4, we deduced an expression for the growth rate as a function of the temperature and the SiH_4 partial pressure. A qualitative model for surface roughening due to carbon incorporation is proposed. From that, we observed that the surface diffusion of carbon adatoms is limited by hydrogen coverage.