Surface Void Migration in Copper (Cu) VLSI Interconnect

Electromigration-induced void evolutions in various dual-inlaid Copper (Cu) interconnect structures were simulated by applying a phenomenological model resorting to Monte Carlo based simulations, which considers redistribution of heterogeneously nucleated voids and/or pre-existing vacancy clusters at the Cu/dielectric cap interface during electromigration. The results indicate that this model can qualitatively explain the electromigration-induced void evolutions observations in many studies reported by several researchers heretofore. These findings warrant need to reinvestigate technologically important electromigration mechanisms by developing rigorous models based on similar concepts.