Surface roughness and grain boundary scattering effects on the electrical conductivity of thin films

In this work, we investigate surface/interface roughness and grain boundary scattering effects on the electrical conductivity of polycrystalline thin films in the Born approximation. We assume for simplicity a random Gaussian roughness convoluted with a domain size distribution ~e^-πr^2/ζ^2 to account for finite grain size effects with ζ, the average domain size. For semiconducting quantum wells a peculiar interplay takes place between quantum mechanical and roughness-grain boundary scattering effects as a function of the domain size ζ and the roughness correlation length ξ. For metallic films grain boundary scattering becomes significant for domain sizes comparable to the roughness correlation length ξ