Electromigration behaviour of 0.3 /spl mu/m damascene vs. plasma-etched interconnects: a lifetime and drift analysis

The electromigration behaviour of 0.3 /spl mu/m wide Al(Cu) damascene interconnects has been studied both by lifetime testing and drift experiments and results are compared to equivalent plasma-etched lines. The lifetime degradation observed for the damascene implementation is consistent with the relative contribution of incubation time and diffusivity, as extracted from the drift study. This is shown to be an intrinsic effect related to the different nature of the interfaces in both metallization schemes.