Adhesion between a copper metallization layer and a dielectric barrier film may be promoted by stabilizing a flow of a silicon-containing precursor in a divert line leading to the chamber exhaust. The stabilized gas flow is then introduced to the processing chamber to precisely form a silicide layer over the copper. This silicidation step creates a network of strong Cu—Si bonds that prevent delamination of the barrier layer, while not substantially altering the sheet resistance and other electrical properties of the resulting metallization structure.