A new seeding and electroless approach to alloying,direct patterning,and self-forming barriers for Cu thin-film nanostructures

In contrast to the previous studies involving sputter deposition to form Cu-alloy thin films with several atomic percentages of incorporated metallic solutes, this work examines the feasibility of using electroless deposition in conjunction with a new site-selective seeding process for the alloying and direct patterning of Cu thin-film nanostructures on dielectric layers. Very minute amounts (0.4 at.%) of manganese can be incorporated into the constituting Cu and segregated to form an interfacial layer at the SiO₂/Cu interface upon annealing in an Ar–H₂ atmosphere. The interfacial layer made up of only a few atomic layers is identified based on synchrotron X-ray spectroscopy and serves as a barrier for advanced technology nodes.