Molecular design for novel radiation resist decomposable by electron detachment

Molecular structures that can be dissociated into two fragments in cryogenic solid by electron detachment have been investigated for constructing high-resolution radiation resists that are free from blur due to the migration of secondary electrons. Within examined molecules that are known to be dissociative by electron detachment in liquids, only the radical cations of (C₆H₅)₂(OH)C–CH(OH)C₆H₅ and [(CH₃C₆H₅)(C₆H₅)(OH)C–]₂ dissociate into benzyl-type radicals and cations. A polymer containing these molecules at the center of the skeleton can be used as a resist with high sensitivity and high spatial resolution, since the exposure of ionizing radiation causes stepwise reduction of the molecular weight by direct ionization.