integrated circuits include networks of electrical components that are typically wired , or interconnected , together with aluminum wires . in recent years , researchers have begun using copper in combination with diffusion barriers , rather than aluminum , to form the wires . unfortunately , typical diffusion barriers add appreciable resistance to the wiring and require costly fabrication methods . accordingly , the inventors devised one or more exemplary methods for making integrated - circuit wiring from materials , such as copper -, silver -, and gold - based metals . one exemplary method removes two or more masks in a single removal procedure , forms a low - resistance diffusion barrier on two or more wiring levels in a single formation procedure , and fills insulative material around and between two or more wiring levels in a single fill procedure . this and other embodiments hold the promise of simplifying fabrication of integrated - circuit wiring .