Damage of Interconnects by Electromigration Induced Surface Evolution

Under intensive electric current, exposed aluminum interconnects undergo surface evolution driven by electromigration. The evolution of the surface morphology induces fluctuations in electric field. When the surface diffusivity is inhomogeneous, surface damage appears under electric current as a combination of stationary solution and transients. The experimental observations confirm the above theoretical predictions and raise the reliability issue of electromigration in polycrystalline interconnects.