AC and pulsed-DC stress electromigration failure mechanisms in Cu interconnects

Abstract

The effects of AC and pulsed-DC (PDC) waveforms on electromigration failure distributions in Cu / low-k interconnects are examined. No failures are observed with a 1MHz pure AC stress, consistent with average current density controlled kinetics and complete recovery of damage during current reversal. Failure distributions with PDC stress are consistent with a degradation process that is determined by average current density and void growth kinetics.