Selective PVD growth of copper on patterned structures by selectively resputtering and sputtering areas of a substrate

摘要

Features, e.g., vias or lines, are formed of copper by using selective PVD growth. A patterned structure is formed having a underlayer of a material that will accumulate copper by sputtering. An overlayer resputters the copper so that it does not accumulate a layer of copper. Copper is resputtered onto the underlayer using a sputtering ion that has a higher molecular weight than the copper. Copper is used to fill the gap defining the desired feature, and to cover an overlayer. Polishing and etchback are then used to remove the resputtered thin material and remove all of the copper on the upper surface, leaving the copper feature.