Siloxane and silsesquioxane copolymers have been synthesized and first evaluated as
potential components of 157 nm resist materials. In block copolymers of dimethylsiloxane
and tert-butyl methacrylate negative imaging chemistry dominates at 157 nm, due to the
presence of the siloxane component, although positive imaging in aqueous base
developers via chemical amplification was obtained at longer wavelengths (248 nm). The
same behavior is observed in graft copolymers of dimethylsiloxane and tert-butyl …