Current-induced dark layer formation for metallization in electronic devices

A method of forming a microelectronic device, the method comprising:

• providing a substrate;
• depositing over the substrate a base layer comprising an alloy of Cu and/or Mo with 0.5 weight %-50 weight % of one or more anodizable alloying elements selected from the list consisting of Ta, Nb, Al, Hf, Zr, Ti, and Mg;
• anodizing the base layer to form a bilayer barrier layer comprising (i) a dielectric layer and (ii) a remaining portion of the base layer disposed beneath the dielectric layer;
• and
• depositing a conductor layer over the barrier layer.