Semiconductor structures with airgaps and/or metal linings and methods of manufacture are provided. The method of forming an airgap in a wiring level includes forming adjacent wires in a dielectric layer. The method further includes forming a masking layer coincident with the adjacent wire and forming a first layer on the masking layer to reduce a size of an opening formed in the masking layer between the adjacent wires. The method further includes removing exposed portions of the first layer and the dielectric layer to form trenches between the adjacent wires. The method further includes forming an interlevel dielectric layer upon the dielectric layer, where the interlevel dielectric layer is pinched off from filling the trenches so that an airgap is formed between the adjacent wires. A metal liner can also be formed in the trenches, prior to the formation of the airgap.