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

Abstract

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 $\ensuremath{\sim}{e}^{\ensuremath{-}\ensuremath{\pi}{r}^{2}/{\ensuremath{\zeta}}^{2}}$ to account for finite grain size effects with \ensuremath{\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 \ensuremath{\zeta} and the roughness correlation length \ensuremath{\xi}. For metallic films grain boundary scattering becomes significant for domain sizes comparable to the roughness correlation length \ensuremath{\xi}.