Thickness dependent thermal capacitance of thin films with rough boundaries

We investigated the thickness dependence of the thermal capacitance of thin films with evolving boundary roughness as a function of film thickness. Besides dynamic roughness evolution, also thickness variations of the film thermal conductivity were taken into account for the more general case of polycrystalline films. Nevertheless, the roughness evolution with film thickness is shown to be the dominant factor, modified by details of the corresponding scattering mechanisms that determine charge and heat carrier transport at low film thickness in comparison with the heat carrier mean bulk mean free path.