| abstract |
A layered structure includes a substrate; an underlayer including a reversibly crosslinked polymer and/or oligomer interconnected by ester functionalities; a silicon-containing mask overlaying the underlayer; and a photoresist overlaying the silicon-containing hardmask layer. Also described are multilayer lithographic processes and processes of forming the underlayer, which generally includes coating an underlayer composition onto a surface of the substrate at a thickness effective to provide a planar upper surface, wherein the underlayer composition includes a polymer including terminal alcohol groups, a multifunctional anhydride, and a solvent. The underlayer composition is heated to a temperature to effect a crosslinking reaction between the multifunctional anhydride and the terminal alcohol groups to form the ester functionalities, which can be selectively removed (reversibly crosslinked) using a wet etchant. |