Patent ID: 8828870

Claim:
A method of forming a metal interconnect structure, comprising: forming a dielectric material layer containing a recessed line pattern; forming a metallic barrier layer on the dielectric material layer at sidewalls of the recessed line pattern; forming a copper-containing seed layer on the metallic barrier layer; electroplating a copper-containing layer on the copper-containing seed layer, wherein at least one of the copper-containing seed layer and the copper-containing layer comprises a copper-manganese alloy containing a manganese concentration from about 1 ppm to about 10 atomic percent; and planarizing the copper-containing layer, wherein a remaining portion of the copper-containing seed layer and the copper-containing layer constitutes a copper-manganese alloy line, wherein a grain size measured at a bottom of the copper-manganese alloy line exceeds a width of the copper-manganese alloy line at least every “Blech” length.