Thermal phenomena in acrylic 193 nm resists

A combination of methods has been applied to determine the glass transition and decomposition temperatures for several series of methacrylic copolymers used in commercial 193 nm resists as a function of the environment experienced by the protective group. The deprotection of the MAdMA and MLMA monomers which are the basis of the commercial AZ(R)EXP AX-1000P system is not appreciably catalyzed by the presence of MAA comonomers, leading to the conclusion that there is no autocatalytic effect in the deprotection of photoresists using these groups. AZ(R)EXP AX1000P is found to have a high Tg of about 154 degrees C, which is corroborated by thermal flow measurements of developed resist features. Due to a decomposition process initiated by one of the other resist components, the formulation is presently not of the annealing type.