The present disclosure relates to an integrated chip comprising a substrate. A first conductive wire is over the substrate. A second conductive wire is over the substrate and is adjacent to the first conductive wire. A first dielectric cap is laterally between the first conductive wire and the second conductive wire. The first dielectric cap laterally separates the first conductive wire from the second conductive wire. The first dielectric cap includes a first dielectric material. A first cavity is directly below the first dielectric cap and is laterally between the first conductive wire and the second conductive wire. The first cavity is defined by one or more surfaces of the first dielectric cap.