Electrical and Structural Characterization of Electromigration in Al-Si/Ti Multilayer Interconnects

In this work we investigate the correlation between the resistance behaviour and the mass transport in narrow line interconnects with a laminated structure incorporating multiple layers of Ti in Al-Si. For comparison, homogeneous Al-Si films are also studied. The electromigration resistance is evaluated by applying a temperature-ramp resistance analysis (TRACE) at direct wafer level. The improved stability against electromigration in the laminated structures is related to the formation of a continuous barrier of the intermetallic compound TiAl3, preventing voids from propagating across the film.