Copper Electromigration Improvement Through Aluminum Barrier and Related Process Optimization

Electromigration (EM) failure is one of the major concerns for back-end-of-line (BEOL) with Cu interconnects. Many factors contribute to Cu EM failure. Study shows Cu Al barrier, and the related process has a significant role in managing Cu EM issue in the thick Cu process. In this paper, we reviewed possible EM failure mechanisms and, a significant improvement of EM lifetime is achieved for a thick Cu process by optimization of Al barrier and related processes.