Copolymers of camphorsulfonyloxymaleimide and t-BOC protected vinyllactams for applications as single-component resists

N-(10-Camphorsulfonyloxy)maleimide (CSOMI) have been copolymerized with two t-BOC protected vinyllactams, 3-(t-butoxycarbonyl)-1-vinyl-2-pyrrolidinone (BCVP) and 3-(t-butoxycarbonyl)-1-vinylcaprolactam (BCVC) to make photoacid-generating polymers P(CSOMI/BCVP) and P(CSOMI/BCVC), respectively. The thermal and photoacidolytic deprotection of the t-BOG protected copolymers readily underwent by UV exposure and solubilities of the polymers were remarkably changed thereafter. The polymers were proved to have the capability of a single-component, chemically amplified resist system in the deep-UV region without addition of any photoacid generator, because the polymers themselves photochemically generate a bulky 10-camphorsulfonic acid (SCA). The polymer films gave positive tone images by irradiation with electron beam (EB) and development with aqueous base solutions.