Integration of High Performance and Low Cost Cu/Ultra Low-k SiOC(k=2.0) Interconnects with Self-formed Barrier Technology for 32nm-node and Beyond

A method of integrating high performance and low-cost Cu ultra low-k (ULK) SiOC(k=2.0) hybrid interconnects with SiOC(k=2.65) hard mask structure has been developed. The method combines Cu/ULK interconnects with the self-formed MnO x barrier layer that was shown to have lower resistance and higher reliability than Cu alloys. Moreover, dual-damascene (DD) interconnects with MnO x barrier layer showed excellent stress-induced voiding performance and significantly longer electromigration lifetime and required no additional pore-sealing process. It is concluded that this self-formed barrier process is the most feasible technology for 32 nm-node Cu/ULK interconnects.