Dependence of film surface roughness on surface migration and lattice size in thin film deposition

This work focuses on the study of the dependence of film surface roughness on surface migration and lattice size in thin film deposition processes. Two different models of thin film deposition processes, in both one-dimension and two dimensions, are considered: random deposition with surface relaxation model and deposition/migration model. Surface roughness is defined as the root-mean-squares of the surface height profile and is found to evolve (starting from a flat initial surface zero value) to steady-state values at large times. A linear and a logarithmic dependence of surface roughness square on lattice size are observed in the one-dimensional and two-dimensional lattice models, respectively, in both the random deposition with surface relaxation model and the deposition/migration model with zero activation energy contribution from each neighboring particle. Furthermore, a stronger lattice-size dependence is found in the deposition/migration model when the migration activation energy contribution from each neighboring particle becomes significant.