Attempts to improve the reliability of narrow passivated Al/Cu conductors as defmed by the performance in an accelerated electromigration test are reviewed. The results are explained in terms of the effect of thermally induced stress and stress voiding on electromigration lifetime. Other processing variations which produced small or inconsequential changes are also discussed. In addition, it was observed that electromigration perfonnance in samples susceptible to stress voiding was degraded as a function of storage time at room temperature.