High performance refractory metal / copper interconnects to eliminate electromigration

Abstract

An interconnect structure and method of making the same. A preferred interconnect structure has a first interconnect including a first dual damascene via and narrow line and a second interconnect at the same level as the first including a second dual damascene via and wider line. The first and second interconnects may have different aspect ratio and may have different line heights while being co-planar with each other. The second line of the second interconnect may abut or partially surround the first line of the first interconnect. The first interconnect includes a refractory metal material as the main conductor, whereas the second interconnect includes a lower resistivity material as its main conductor.