Numerical Simulation of Threshold Current Density of Electromigration Damage in Cu Interconnect Tree

As silicon integrated circuits (ICs) continue to scale down, several reliability issues have emerged. Electromigration — the transportation of metallic atoms by the electron wind — has been recognized as one of the key damage mechanisms in metallic interconnects. It is known that there is the threshold current density of electromigration damage in via-connected line. The evaluation of the threshold current density is one of the great interests from the viewpoint of IC reliability. Recently, the threshold current density in interconnect tree was evaluated. However, it might not be so accurate because of evaluation of two-dimensional structure by combining one-dimensional analysis. In this study, the evaluation method of the threshold current density based on the numerical simulation is applied to several kinds of interconnect tree.