A method of forming at least a partial air gap within a semiconducting device and the resulting devices, said method comprising the steps of: (a) depositing a sacrificial polymeric composition in one or more layers of the device during its formation; (b) coating the device with one or more layers of a relatively non-porous, organic, polymeric, insulating dielectric material (hardmask) having a density less than 2.2 g/cm³; and (c) decomposing the sacrificial polymeric composition such that the decomposition products permeate at least partially through the one or more hardmask layers, thereby forming at least a partial air gap within the device.