Method for forming a tungsten interconnect structure with enhanced sidewall coverage of the barrier layer

摘要

By performing a re-sputter process during the formation of a barrier layer for a contact opening in a tungsten-based process, the reliability of the tungsten deposition, as well as the performance of the resulting contact plug, may be enhanced. During the re-sputtering process, a thickness of the titanium-based barrier layer may be reduced at the contact bottom, while at the same time the material is re-condensed on critical lower sidewall portions of the contact opening.