Acid Generation Mechanism for Extreme Ultraviolet Resists Containing Pinanediol Monosulfonate Acid Amplifiers: A Pulse Radiolysis Study

Very highly sensitive resists are required for extreme ultraviolet (EUV, 13.5 nm) lithography, which is regarded as the most promising next-generation lithography. Chemically amplified resists have been proposed to increase acid yield and sensitivity through the use of an acid amplifier. There are two steps for acid generation in chemically amplified resists: initial acid generation and acid amplification. The first systematic research on the acid generation mechanisms of chemically amplified resists showing the involvement of acid amplifiers has been performed by both time-resolved pulse radiolysis and spectrophotometric titration methods. The role of acid amplifiers in acid generation processes, initiated by exposure, has been clarified using toluene and trifluoromethylbenzene derivatives of pinanediol monosulfonate. (C) 2012 The Japan Society of Applied Physics