Three-dimensional simulation of void migration at the interface between thin metallic film and dielectric under electromigration

Abstract

A kinetic Monte Carlo simulation of the electromigration-induced void migration behavior of three-dimensional nanovoids at the interface between a metal conductor and its dielectric overlayer is presented. Major stages of the recently observed failure mode of surface void migration and accumulation at the cathode via of Cu damascene interconnects were simulated, including the trapping at and detachment from grain boundaries (GBs) and GB triple junctions. The migration and shape evolution of voids along the interface and along the grain boundaries intersecting this interface have also been investigated in detail. The main results of the simulation correlate well with in situ observations as well as with simple analytical models of void trapping and detachment from GBs and their junctions.