METHOD OF FABRICATING COPPER INTERCONNECTIONS IN SEMICONDUCTOR DEVICES

A method is provided for forming a copper interconnect, the method including forming a first dielectric layer above a structure layer, forming a first opening in the first dielectric layer, and forming a first copper structure in the first opening. The method also includes forming a sacrificial dielectric layer above the first dielectric layer and above the first copper structure, forming a second opening in the sacrificial dielectric layer above at least a portion of the first copper structure, and forming a second copper structure in the second opening, the second copper structure contacting the at least the portion of the first copper structure. The method further includes removing the sacrificial dielectric layer above the first dielectric layer and adjacent the second copper structure, and forming the copper interconnect by annealing the second copper structure and the first copper structure.