Regularization of pattern formation in heteroepitaxial thin films through surface diffusivity modulation

A numerical study is presented to demonstrate the influence of local diffusion variation during laser-thermal treatment on the growth dynamics of silicon-germanium thin films. A surface morphology evolution equation is developed with the assumption that the diffusivity is a spatially varying function induced by a sinusoidal surface temperature profile. Results show that an initially flat film evolves into patterns through the thermal modulation, indicating that the growth can be controlled by enhancing local diffusivity. The present study is expected to provide a path for future laser-annealing experiments to produce regularized quantum dots.