Numerical Modeling of Electromigration in Al(0.25 at. % Cu) Interconnects

ElectromigrationElectromigration is a failure mechanism of major interest in the microelectronicsMicroelectronics industry. It is well known that introducing Cu solute into Al interconnectsAl interconnects greatly increases the resistance against electromigrationElectromigration degradation. AlAl electromigrationElectromigration is significantly slowed by the presence of Cu solutes until they are preferentially electromigrated away, and it only occurs within the Cu-depleted region where a resulting short-range stress gradient was hypothesized. In this study, a numerical model is developed to simulate the effects of Cu solute on electromigrationElectromigration induced short-range stress development in an AlAl(0.25 at.% Cu) interconnect. The simulation results are compared with a recent set of experimental observations by an X-ray microbeam technique to extract materialMaterials parameters related to the electromigrationElectromigration processProcess in AlAl(Cu) alloy. This study could further our understanding of electromigrationElectromigration mitigation, particularly for alloy-based interconnects in advanced IC technologiesTechnology.