Effect of the crystallinity of a grain boundary on the self-diffusion of copper in thin-film interconnections

Abstract

In this study, the effect of the crystallinity and the characteristics of grain boundaries on the grain boundary diffusion was investigated experimentally. The crystallinity and characteristics of the grain boundaries were evaluated by using an EBSD (Electron Back-scattered Diffraction) method. The atomic diffusion of the grain boundary was also observed as the change of the surface morphology of interconnections by SPM (Scanning Probe Microscopy). It was found that the main diffusion paths during EM (Electro Migration) was random grain boundaries. The grain boundaries with low quality, regardless of crystallographic orientation, were also the main atomic diffusion paths.