| abstract |
Novel ester compounds having formulae (1) to (4) wherein A1 is a polymerizable functional group having a carbon-carbon double bond, A2 is oxygen, methylene or ethylene, R1 is a monovalent hydrocarbon group, R2 is H or a monovalent hydrocarbon group, any pair of R1 and/or R2 may form an aliphatic hydrocarbon ring, R3 is a monovalent hydrocarbon group, and n is 0 to 6 are polymerizable into polymers. Resist compositions comprising the polymers as a base resin are thermally stable and sensitive to high-energy radiation, have excellent sensitivity and resolution, and lend themselves to micropatterning with electron beam or deep-UV. |