Surface roughening in homoepitaxial growth: A lattice gas cellular automaton model

Abstract

We study the structural evolution of a growing thin film on time scales in the order of seconds and even minutes. This requires solving the problem of bridging large time and length scale gaps in simulating atomistic processes during thin film deposition. We describe a new simulation approach inspired by lattice gas cellular automata to address this problem. The approach is based on a discrete description of atoms so that the unit length scale coincides with the atomic diameter. For homoepitaxial thin film deposition, the local driving force is the propensity of an atom to establish as many chemical bonds as possible to the underlying substrate atoms when it executes surface diffusion. The interaction between atoms is defined using a coarse-grained approach to boost the computation speed without heavily sacrificing the atomistic details. Simulation results of Si layers deposited on a Si(001) substrate are presented. © Springer-Verlag 2004.