Barrier metal effects on electromigration of layered aluminum metallization

An investigation was conducted of the electromigration (EM) in Al-1% Si, Al-1% Si-0.5% Cu, and Al-2% Cu films with Ti:W and CVD-W barrier metals. The EM test results indicate that the rough surface texture of the underlying CVD-W layer degrades the electromigration performance of the Al-1% Si and Al-1% Si-0.5% Cu films. However, the EM performance of Al-2% Cu multilayered metallization was found to be independent of the barrier metal type. The failure kinetics of multilayered metallization was studied by investigating the resistance rise mechanism. The resistance rise during EM testing of CVD-W/Al-1% Si-0.5% Cu and Ti:W/Al-1% Si-0.5% Cu seems to be well behaved and follows a power law dependence