Impact of via geometry and line extension on via-electromigration in nano-interconnects.

Via topology and line extension length can impact current crowding, stress distribution and void dynamics in the cathode region of nano-interconnects and therefore have an impact on electromigration lifetimes. In this study, a 2D physics-based model is employed to capture the effect of line extension and via taper angle on stress evolution and void dynamics, quantitatively. Varying via taper angle is shown to have higher impact on peak stress reduction (similar to 0.8 MPa/nm of extra space) compared to line extension (similar to 0.08 MPa/nm of extra space).