Comparison of Process Options for Improving Backend-of-Line Reliability in 28 nm Node Technologies and Beyond

This paper compares the most encouraging process options for improving electromigration performance in advanced technology nodes. Metal capping yields the best electromigration performance; however, this process is most challenging with respect to integration and may also suffer from significantly decreasing grain sizes in trench bottoms for future technologies. Alloying or silicidation techniques are less challenging to implement but can result in unacceptably high resistance increases. We analyze the respective results for each option and compare the performance on 45, 32, and 28 nm technology nodes. In addition, the impact of the various process options on stressmigration and time-dependent dielectric breakdown are discussed.