ESD Effects on Electromigration Performance of Aluminum Metallization Systems

The semiconductor industry continues to challenge designer’s ability to provide adequate protection for ESD by scaling to ever-smaller geometries. The metal lines used to connect these circuit elements are also scaled. The effect of non-destructive ESD events on aluminum metal lines is investigated showing a reduction in electromigration lifetime for ESD events close to the failure threshold of the metal. The mechanism contributing to the reduction is a change in the microstructure of the metal resulting in void formation similar to traditional electromigration damage rather than melting and crystallization into smaller grains.