Abstract
In this study, the change of the crystallographic quality of electroplated copper thin-film interconnections due to stress-induced migration was investigated by using an EBSD (Electron Back Scatter Diffraction) method. This EBSD analysis clearly showed that the crystallinity of the annealed electroplated copper thin-film was degraded during the storage of the interconnection even at room temperature without any loading. This is due to the stress-induced migration caused by high tensile residual stress which occurred in the film after annealing. Molecular dynamics simulations showed that the diffusivity of copper atoms along grain boundaries with low crystallinity was enhanced significantly by high tensile residual stress. Therefore, the grain boundary diffusion accelerated by tensile residual stress is the main reason for the degradation of crystallinity the thin film interconnection after annealing.
