Patent ID: 8728717

Claim:
A method for making an enclosed air-gap structure comprising: forming either a sacrificial polymer bilayer film (PAG bilayer) on a substrate or a sacrificial polymer unilayer film (PAG-doped unilayer) on said substrate where both the bilayer film and the unilayer film comprise a photoacid generator moiety having a concentration gradient therethrough; imagewise exposing said bilayer or unilayer film to actinic radiation thereby forming exposed portions and unexposed portions thereof; heating said exposed bilayer or unilayer film to a first temperature (T 1 ) effective for decomposing the sacrificial polymer of said exposed portions; forming an overcoat layer overlying said unexposed portions; and heating said unexposed portions to a second temperature (T 2 ) effective for decomposing the sacrificial polymer thereof, where decomposition products of such decomposing permeate through said overcoat layer thereby forming said enclosed air-gap structure.