Kinetics of Electromigration Mass Transfer in the Interface Elements of Micro- and Nanoelectronics Depending on the Strength of Thin-Film Connections

Abstract

This study improves and expands the scope of application of the theoretical model previously proposed by the authors, which describes the relationship between the strength and electromigration (diffusion) properties of interfaces formed by connected materials. In the developed model, a linear relationship is established between the values of the work of reversible interface separation \({{W}_{a}}\) and electromigration activation energy \({{H}_{{EM}}}\) in the interface. Estimates are made and the coefficients of the resulting relation are compared with experiments studying electromigration in a copper conductor coated with a protective dielectric. Using also the model previously developed by the authors, which describes the dependence of the quantity \({{W}_{a}}\) on the concentrations of nonequilibrium lattice defects presenting in the volumes of connected materials, a number of effects due to the influence of such defects on processes caused by electromigration are predicted and studied. This study shows that by introducing nonequilibrium lattice defects in the form of atomic interstitial or substitutional impurities into the volumes of the joined materials, we can effectively influence on the characteristics of the electromigration instability of the shape of the interlayer boundary. For interstitial impurities, quantitative analytical estimates of the impurity concentration required to significantly change (both increase and decrease) the characteristic growth time of the instability of the shape of an initially flat interface are performed.