Patent ID: 8008199

Claim:
A method of forming a metal interconnect structure comprising: providing a dielectric material layer containing a recessed line pattern; forming a metallic barrier layer directly on said dielectric material layer at sidewalls of said recessed line pattern; forming a copper-containing seed layer directly on said metallic barrier layer; electroplating a copper-containing layer directly on said copper-containing seed layer, wherein at least one of said copper-containing seed layer and said copper-containing layer comprises a copper-cobalt alloy containing a cobalt concentration from about 1 ppm to about 10 atomic percent; and increasing grain size and decreasing resistance within said copper-containing seed layer and said copper-containing layer, wherein said copper-containing seed layer and said copper-containing layer form a bamboo microstructure within said recessed line pattern, and wherein each grain boundary within said bamboo microstructure extends to a bottom surface of said copper-containing layer.