The electromigration (EM) behaviour of damasene Al(Cu) - interconnects has been studied for the first time by drift experiments and results directly compared to plasma-etched lines. For the latter EM is known to occur through sequential stages: an incubation period, needed for Cu-depletion, and an Al-drift stage. It is shown that using a damascene implementation, the incubation time significantly increases but the Al-drift velocity does as well. This is demonstrated to be an intrinsic effect, directly related to the technological nature of both metallization schemes. Implications on lifetime prediction at operating conditions are discussed.
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