Process characteristics of an all-organic chemically amplified deep-ultraviolet resist

An all-organic chemically amplified positive deep-ultraviolet resist has been developed that demonstrates 0.35-mu-m resolution at a dose of approximately 18 mJ/cm2 of 248 nm KrF laser radiation. Good critical dimension uniformity and process latitude were demonstrated. Additionally, use of an overcoat material applied immediately after resist coating reduces the dependence of the resist on the time delay between exposure and post-exposure bake. Efforts relating to process optimization will be described in conjunction with current process performance capabilities and limitations. Additionally, a comparison between triphenylsulfonium hexafluoroarsenate onium salt and nitrobenzyl ester resist formulations will be discussed for select process steps.