Computer simulations of the self-organized 3-D islanding in epitaxial thin film systems?

3-D computer simulations were carried out to investigate the effects of surface energy anisotropy and initial surface roughness on the self-organization of 3-D islands in epitaxial thin film systems. Under the present scheme, the driving force for surface diffusion is the gradient of surface chemical potential, which includes strain energy and surface energy. The simulations demonstrate that the typical sequence of surface evolution is from an initial random surface to a rippled surface, then to irregular islands and then to self-organized islands. Whether the final islands an regular or not depends on both the form of surface energy anisotropy and initial surface roughness. However, the stability and shape transition of the epitaxially strained islands are associated with the form of surface energy anisotropy. The comparisons between the simulations and various experiments were also discussed.