A method for AlCu interconnect electromigration performance predicting and monitoring

The physical properties of (bottom)Si/SiO2/Ti(top) and (bottom)Si/SiO2/Ti/TiN/Al(0.5 wt.% Cu)(top) structures by different processes were compared and studied. The resistivities of thin Ti films and the reflectivities of thin Al alloy films were found to correlate to their microstructure as well as the mean time to fail (MTTF) in electromigration (EM) testing. A method to predict and monitor the EM performance of the AlCu interconnects was proposed.