Effects of crystalline microstructure on epitaxial growth.

Abstract

The results of kinetic Monte Carlo simulations of epitaxial growth on fcc(100) and bcc(100) surfaces in which the correct crystal geometry is taken into account are reported. The existence of downward funneling to fourfold hollow sites leads to a downward current for large angles and to angle selection as observed in a variety of experiments. We have used our model to simulate Fe/Fe(100) deposition at room temperature and have compared our results with recent experiments. Excellent agreement is found for the selected angle, mound coarsening exponent n, and kinetic roughening exponent \ensuremath{\beta} as well as for the mound morphology. A theoretical analysis also leads to an accurate prediction of the observed mound angle for Fe/Fe(100) deposition at room temperature. The general dependence of the surface skewness, mound angle, and coarsening kinetics on temperature, deposition rate, and strength of the step barrier to interlayer diffusion is also studied and compared with recent experiments. While for a moderate step barrier we find an effective coarsening exponent n\ensuremath{\simeq}0.16--0.25, for the case of a very large step barrier we find n\ensuremath{\simeq}1/3, which is significantly larger than found in previous models but in agreement with recent experiments on Rh/Rh(111). \textcopyright{} 1996 The American Physical Society.