Abstract: The reliability and electromigration performance of planarized metallization patterns in an electrical device, for example copper, inlaid in the surface of a layer of dielectric material overlying a semiconductor substrate, are enhanced by a method for more reliably and uniformly diffusing into a conductive fill alloying elements which reduce or substantially prevent electromigration. The method comprises depositing around a conductive fill metal alloy films and alloying layers comprising one or more alloying elements having physical and/or chemical attributes which are effective for minimizing or substantially preventing electromigration along grain boundaries and/or along the interface between the surfaces of the conductive fill and other surfaces. The metal alloy films and alloying layers are advantageously deposited where their particular physical and/or chemical attributes may be most beneficial for improving electromigration performance.