Electromigration-induced damage of Au conductor lines

Electromigration-induced evolution of surface morphology of Au conductor lines at different stages of their degradation and damage is investigated by optic microscopy and scanning tunneling microscopy (STM). The investigation of the surface morphology of Au films with STM showed, that formation, coalescense and migration of micropores resulted from electromigration lead to the accumulation and the depletion of the material transported along the direction of passing the electric current, inducing the following damage of Au films. It is shown that the density of electric current passing through thin conducting films greatly affect their lifetime. Fractal analysis is employed to estimate numerically changes of Au film surface relief. The fractal dimension is shown to be an optimum prefracture criterion of thin metal films during passing the electric current