Lactone-containing compound, polymer, resist composition, and patterning process

摘要

Lactone-containing compounds having formula (1) are novel wherein R 1 is H, F, methyl or trifluoromethyl, R 2 and R 3 are H or monovalent hydrocarbon groups, or R 2 and R 3 may together form an aliphatic hydrocarbon ring, R 4 is H or CO 2 R 5 , R 5 is a monovalent hydrocarbon group, W is CH 2 , O or S, and k 1 is 3, 4 or 5. They are useful as monomers to produce polymers which are transparent to radiation s 500 nm. Radiation-sensitive resist compositions comprising the polymers as base resin exhibit excellent properties including resolution, LER, pattern density dependency and exposure margin.