EM behaviors depend on not only metal materials but also the structure of the interconnects.
The Cu line fed with a W contact has a shorter lifetime than that of Cu fed with a Cu contact.
Mean time-to-failure for Cu interconnects can be enhanced under AC and pulsed DC.
Mean time-to-failure for Cu interconnects was independent of the frequency of the pulsed DC.
Mean time-to-failure for Cu interconnects increased with the off-time period.