Physical analysis of electromigration damage under bidirectional (BC) and pulsed DC (PDC) conditions

Physical failure analysis has been performed on Al-Si metal interconnects stressed for electromigration under bidirectional (BC) and pulsed unidirectional (PDC) currents. Electrically measured resistance changes due to void formation have been compared in estimates obtained from direct void observation under the SEM and a correlation between them has been established. The results provide support to the average current model proposed for EM by J.A. Maiz (1989). The influence of microstructural and geometrical parameters in EM void generation has also been studied and it has been concluded that the type and location of the PDC and BC Em generated voids are similar to that observed under DC conditions.<
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