MOLECULAR-BEAM EPITAXIAL-GROWTH OF SI(001) - A MONTE-CARLO STUDY

The results of a Monte Carte (MC) simulation study of epitaxial growth dynamics of Si(001) over a wide range of deposition rates (0.001-100 monolayers/s) and substrate temperatures (500-1000 K) are reported. Th e MC model, which allows the formation of bulk vacancies and overhangs in the tetrahedral coordination of silicon, is proposed. Surface rela xation (dimerization) and atom-atom interactions extending as far out as second-neighbour sites are included in the model. Our results demon strate that the effect of the formation of vacant sites is pronounced only at low temperatures, where there is no active hopping of atoms, w hile at high temperatures this effect is washed out by intensive hoppi ng of atoms.