Progress in 193 nm positive resists

We used the tertiary-butyl ester protecting group for the construction of our 193-nm resists.[l] This paper describes an investigation of the impact of acid-cleavable protecting group structure on the properties of a series of model acrylic polymers. In this investigation, factors such as thermochemical stability, reactivity to photogenerated acid, and dissolution properties of exposed films as a function of dose were examined. The impact of photo-add structure and its role in the dissolution properties of exposed films will also be discussed. Additionally, we will introduce a new cycloaliphatic polymer family (polynorbomenes) with superior etch resistance, significantly broadening the polymer chemistry available for the construction of new 193-nm photoresists. [2] ©1996 TAPJ.