Concluding remarks

With shrinking device size and interconnect dimension, electromigration (EM) in the interconnects had become the main failure mechanism that determined IC reliability. The conventional physics based 3D EM models were at the “localized” regions and thus could not represent the EM reliability of an entire circuit. As current density was no longer the sole factor that determined the EM reliability, and the temperature and thermo-mechanical stress distributions of the interconnects in an IC were greatly affected by the interconnect structures and the surrounding materials, the 2D EM circuit simulators based only on current density were no longer adequate. Thus, there is a need for 3D EM modeling at circuit layout level.