A series of styrene monomers was prepared having the structure R-4-t-butoxycarbonyloxystyrene, (R = 2-CH3, 3-Cl). The monomers were copolymerized with sulfur dioxide to give copolymers (PMTBSS and PClTBSS, respectively) with the ratio of styrene to SO2 of approximately 2:1. The polymers were evaluated as single component deep-ultraviolet (DUV) and x-ray resists and compared to PTBSS, the copolymer of 4-t-butoxycarbonyloxystyrene and sulfur dioxide. No enhancement in sensitivity was observed for either new material under standard processing conditions for either DUV or x-ray (1.4 nm) radiation. However, the enhanced thermal stability of PMTBSS allowed higher postexposure bake (PEB) temperatures (150 versus 140-degrees-C), and using a PEB of 150-degrees-C, PMBTSS showed an x-ray sensitivity of 8-10 mJ/cm2 as compared to 18 mJ/cm2 for PTBSS.