Implications of damascene topography for electroplated copper interconnects

As-electroplated copper undergoes a gradual recrystallization at room tempe rature related to the plating chemistry. The influence of damascene topogra phy on the recrystallization as well as on the texture of Cu must be unders tood to optimize properties for superior interconnect performance. A low-te mperature anneal before CMP stabilizes the Cu microstructure and eliminates the (111) sidewall growth component that is observed if the overlying Cu i s removed before recrystallization.