ACID-CATALYZED SINGLE-LAYER RESISTS FOR ARF LITHOGRAPHY

A positive-tone single-layer resist for use with 193-nm radiation has been developed. The system contains a terpolymer of methyl methacrylat e, methacrylic acid, and t-butyl methacrylate, along with a photoacid generator. The chemically amplified deprotection of the t-butyl methac rylate into methacrylic acid increases the polarity of the resist and allows selective dissolution in metal-ion-free aqueous-base solutions. The resist sensitivity is less than 10 mJ/cm2, and its inherent resol ution is better than 0.1 mum. These acrylate-based systems have the po tential to be both lower in cost and have better environmental stabili ty than the deep ultraviolet chemically amplified resists that use phe nolic resins.