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.