Simulation on surface roughness variation of Au thin films by microwave post annealing

A simulation study was performed in order to interpret the experimental results in the previous report on roughness reduction in Au thin films by microwave post annealing in comparison with an electric furnace. The simulation model of this study is based on one-dimensional capillary driven surface diffusion with incorporation of electromigration force due to microwave irradiation. It was shown that alternating microwave electric field does not cancel the atomic migration completely, because of the capillary driven (thermal) effects simultaneously occurring within the alternation period, but is not adequate to account for the variation of the film profiles and the observed wave number spectra. In this study, capillary model was applied to the furnace annealing, and an anisotropic factor in atomic transport by electromigration was introduced in microwave annealing simulations. We reproduced the profiles and spectra changes observed in the experiments by both annealing methods.