An interconnect structure of the single or dual damascene type and a method of forming the same, which substantially reduces the electromigration problem that is exhibited by prior art interconnect structures, are provided. In accordance with the present invention, a grain growth promotion layer, which promotes the formation of a conductive region within the interconnect structure that has a bamboo microstructure and an average grain size of larger than 0.05 microns is utilized. The inventive structure has improved performance and reliability.