Integrated circuits with improved contact structures are provided. In an exemplary embodiment, an integrated circuit includes a semiconductor substrate disposed with a device therein and/or thereon. The integrated circuit includes a contact structure in electrical contact with the device. The contact structure includes a plug metal and a barrier layer, and the barrier layer is selected from fluorine-free tungsten (FFW), tungsten carbide, and tungsten nitride. The integrated circuit further includes a dielectric material overlying the semiconductor substrate. Also, the integrated circuit includes an interconnect formed within the dielectric material and in electrical contact with the contact structure.