Self-Formed Barrier Technology using CuMn Alloy Seed for Copper Dual-Damascene Interconnect with porous-SiOC/porous-PAr Hybrid Dielectric

Self-formed barrier technology using copper (Cu) manganese (Mn) alloy seed was applied for Cu dual-damascene interconnect with porous-SiOC/porous-PAr (k=2.3) hybrid dielectric for the first time. More than 90% yield for wiring and via-chain was obtained. 70% reduction in via resistance was confirmed compared with the conventional process. To estimate the moisture resistance property of self-formed barrier, via resistance change was measured with dummy density pattern. As the result, it was found that the resistance change ratio of via for self-formed barrier does not depend on the dummy density, probably due to the high moisture resistance property of self-formed oxide barrier. In addition, outgas at high temperature is found to be essential to form self-formed barrier for porous dielectric.