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 similar to e(-pi r2/zeta 2) to account for finite grain size effects with zeta 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 zeta and the roughness correlation length xi. For metallic films grain boundary scattering becomes significant for domain sizes comparable to the roughness correlation length xi. [S0163-1829(98)05236-9].