Novel 193-nm positive photoresist composed of ester acetal polymer without phenyl group

1,3-adamantanedicarboxylic acid and acrylpimaric acid were reacted with an aliphatic divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, to give novel ester acetal polymers without phenyl group. These polymers can be dissolved in common solvents and possess high thermal stability. The ester acetal polymer can be quickly decomposed at the presence of strong acid generated by PAG above 100°C and become easily soluble in dilute aqueous base. Two-component photopolymer consisting of the ester acetal polymer and PAG can be used as positive photoresists. The polymer derived from 1,3-adamantanedicarboxylic acid displayed higher transparency at 193 nm and can be used for 193 nm photoresist.