The activation energy for electromigration in bamboo-type passivated lines was determined by performing high-resolution resistance measurements. The very early stages (with a non-linear behavior of the resistance) and the subsequent stages (characterized by an approximately constant rate of resistance change) were analyzed by using a model that correlated electromigration and mechanical stress evolution. An activation energy could be deduced only under conditions of linear resistance increase. Its value was 0.95eV. It was suggested that diffusion at the interface between Al-Si and the barrier metal or the passivation could be responsible for this activation energy.

I.De Munari, A.Scorzoni, F.Tamarri, F.Fantini: Semiconductor Science and Technology, 1995, 10[3], 255-9