Development and evaluation of a Cu composite sheet with embedded high electric conduction path for new interconnect material

In this study, it was aimed to develop a novel interconnect material simultaneously possessing high electrical conductivity and strength. Cu composite sheets were fabricated by forming the high electrical conduction paths of Ag on the surface of high strength Cu alloy substrates by damascene electroplating. As a result, the electrical conductivity increased by 40% thanks to mesh type Ag conduction paths, while the ultimate tensile strength decreased by 20%. Because of macro damascene interface profile, the peel strength of Cu composite sheet prepared by damascene electroplating increased by above 50 times compared to Cu composite sheet by conventional electroplating. As Ag conduction path became finer, pressing formability improved. Al wire wedge bonding was able to be carried out without bondable pads patterning process.