A sharp-interface model for solid-state dewetting with wetting potential

Abstract: We propose a sharp-interface model for solid-state dewetting of thin films with wetting potential, where the wetting effect is incorporated through a thickness-dependent surface energy. The model is governed by surface diffusion together with natural boundary conditions, and describes the morphological evolution of the film-vapor interface. For its numerical approximation, we develop an efficient semi-implicit finite element method based on a Taylor expansion of the wetting-potential term. Numerical simulations in two dimensions show that the proposed model and method can capture various dewetting phenomena. They also indicate that, as the range of the wetting potential tends to zero, the proposed model approaches the sharp-interface model with thickness-independent surface energy proposed in [1]. The model and numerical method are further extended to three dimensions, where the computations capture complex morphological evolution in solid-state dewetting.