On the scaling of thermal stresses in passivated nanointerconnects

Much work has been done in the approximation of the stress state of microelectronic interconnects on chips. The thermally induced stresses in passivated interconnects are of interest as they are used as input in interconnect reliability failure models (stress-driven void growth, electromigration-driven void growth). The classical continuum mechanics and physics typically used is, however, intrinsically size independent. This is in contradiction to the physical fact that at the size scale of a few nanometers, the elastic state is size dependent and a departure from classical mechanics is expected. In this work, we address the various physical causes (and the affiliated mathematical modeling) of the size dependency of mechanical stresses in nanointerconnects. In essence, we present scaling laws for mechanical stresses valid for nanosized interconnects. (C) 2004 American Institute of Physics.