Numerical simulation of Ga atoms migration in molecular-beam epitaxy of GaAs

The results of computational experiments with stochastic model of molecular-beam epitaxial growth of the GaAs crystal are presented. In these experiments the growth of GaAs on flat and vicinal (001) surfaces at various molecular flux densitis and substrate temperatures is simulated by Monte-Carlo method. The quantitative characteristics of Ga atoms migration such as free path length, migration time, diffusion coefficient, and the characteristics of crystal such as As surface concentration, surface roughness, bulk vacancy concentration are determined in the simulations. The resuits of simulation demonstrate the dependency of migration upon growth conditions and the influence of migration on crystal quality.