Multiscale modeling of epitaxial growth processes: Level sets and atomistic models

Epitaxy is the growth of a thin film by attachment to an existing substrate in which the crystalline properties of the film are determined by those of the substrate. No single model is able to address the wide range of length and time scales involved in epitaxial growth, so that a wide range of different models and simulation methods have been developed. This talk reviews several of these models - molecular dynamics (MD), kinetic Monte Carlo (KMC), island dynamics and continuum equations - in the context of layered semiconductors applied to nanoscale devices. We describe a level set method for simulation of the island dynamics model, validation of the model by comparison to KMC results, and the inclusion of nucleation. This model uses both atomistic and continuum scaling, since it includes island boundaries that are of atomistic height, but describes these boundaries as smooth curves.