On the voltage dependence of copper/low-k dielectric breakdown

We investigate the voltage dependence of porous low-k dielectric breakdown. We show that interconnect geometric variability will affect both intrinsic Weibull slope (β) and field acceleration. We proposed a new method to verify the low-k electric field dependence that uses complete failure time distributions instead of single median time to fail values measured at different voltages. Our results show that both E and √E model can describe failure distributions for high and low test voltages, while the failure time data at low-voltages is inconsistent with the prediction from power law, impact damage, and 1/E models.