Abstract: A fabrication method, a product structure, a fabrication method, and a sputtering target for the deposition of a conductive barrier or other liner layer in an interconnect structure. The barrier layer comprises a conductive metal of a refractory noble metal alloy, such as a ruthenium/tantalum alloy, which may be amorphous though it is not required to be so. The barrier layer may be sputtered from a target of similar composition. The barrier and target composition may be chosen from a combination of the refractory metals and the platinum-group metals as well as RuTa. A copper noble seed layer may be formed of an alloy of copper and ruthenium in contact to a barrier layer over the dielectric.