The Detrimental Effect of a Passivation on the Electromigration Lifetime of Narrow Al-Si-Cu Lines

Abstract

Abstract2 mm long, 0.8 μm wide and 0.8 μ thick Al-Si-Cu lines, passivated with a 1.14 μm thick PETEOS SiO2 were found to have a lower electromigration lifetime compared to identical unpassivated lines. The high tensile stress in the passivated lines is assumed to accelerate electromigration failure. This is confirmed by the very low activation energy for electromigration failure in the passivated lines and by the multiple events of recovery during and after electromigration testing, suggesting failure sites are slit voids.