An integrated circuit with increased electromigration lifetime and
allowable current density and methods of forming same are disclosed. In
one embodiment, an integrated circuit includes a conductive line
connected to at least one functional via, and at least one dummy via
having a first, lower end electrically connected to the conductive line
and a second upper end electrically unconnected (isolated) to any
conductive line. Each dummy via extends vertically upwardly from the
conductive line and removes a portion of a fast diffusion path, i.e.,
metal to dielectric cap interface, which is replaced with a metal to
metallic liner interface. As a result, each dummy via reduces metal
diffusion rates and thus increases electromigration lifetimes and allows
increased current density.