Localization and Analysis of Metal-Coating-Related Electromigration Degradation in the 65 Nm Technology Node

With the introduction of 65 nm technology, the cross-sectional dimensions of copper interconnect in some layers are now smaller than 100 nm, which translates to current densities on the order of several MA/cm2. Electromigration as a root cause for chip failure is thus a major concern and is still being examined. In this article, the authors present recent failure analysis studies on metal-coated copper interconnects, using OBIRCH techniques in combination with FIB cross-sectioning and SEM and TEM imaging.