Method of forming copper interconnect capping layers with improved interface andadhesion

摘要

The integrity of the interface and adhesion between a barrier or capping layer and a Cu or Cu alloy interconnect member is significantly enhanced by delaying and/or slowly ramping up the introduction of silane to deposit a silicon nitride capping layer after treating the exposed planarized surface of the Cu or Cu alloy with an ammonia-containing plasma. Other embodiments include purging the reaction chamber with nitrogen at elevated temperature to remove residual gases prior to introducing the wafer for plasma treatment.