An improved lift-off process for multilevel metal structure in the fabrication of integrated circuits by employing lift-off layer formed from polymers which undergo clean depolymerization under the influence of heat or radiation and allow rapid and residue-free release of an "expendable mask". An embedded interconnection metallurgy system is formed by application of the lift-off layer of this invention over a cured polymer film or on an oxygen RIE barrier layer previously deposited on organic or inorganic substrate, followed by another barrier over which is then coated a radiation sensitive resist layer. After definition of the desired resist pattern by imagewise exposure and development, the image is replicated into the barrier by sputter etching in a fluorine containing ambient and subsequently into the base layer down to the substrate by oxygen reactive ion etching which is followed by blanket metal evaporation and finally the lift-off by brief heat treatment at the depolymerization temperature of the lift-off layer, and brief solvent soak.