Electron beam resists based on oxirane functionalised polystyrenes

Copolymers consisting of styrene and 4-ethenyl-phenyloxirane (epoxystyrene) can be synthesised by radical copolymerisation. The flexibility offered by this simple method of synthesis allows the production of a variety of copolymers. The possibility of altering the lithographic parameters by modification of the copolymer makes this method of production highly attractive for the purposes of lithographic optimisation. More so than for the analogous systems based upon epoxy novolak resins which suffer because a range of different polymers that, would allow a worthwhile structure/process optimisation, is not available.