US Patent 9543248 Integrated circuit devices and methods

An integrated circuit device includes a first metal layer including aluminum. The integrated circuit device includes a second metal layer including an interconnect structure. The interconnect structure includes a layer of first material including aluminum. The integrated circuit device includes an inter-diffusion layer that includes aluminum. The inter-diffusion layer is proximate to the first metal layer and proximate to the layer of first material including aluminum. The integrated circuit device includes a self-forming barrier layer that includes aluminum. The self-forming barrier layer is proximate to a dielectric layer and proximate to the layer of first material including aluminum.