Patent ID: 8114570

Claim:
A photoacid generator for chemically amplified resist compositions which generates a sulfonic acid in response to high-energy radiation selected from UV, deep-UV, EUV, electron beam, x-ray, excimer laser, gamma-ray and synchrotron radiation, said sulfonic acid having the general formula (1a): ROC(═O)R 1 —COOCH 2 CF 2 SO 3 − H + (1a) wherein RO is hydroxyl or a substituted or unsubstituted, straight, branched or cyclic C 1 -C 20 organoxy group, R 1 is a divalent C 1 -C 20 aliphatic group which may contain a substituent group having a heteroatom such as oxygen, nitrogen or sulfur, or may form a mono- or polycyclic structure with RO.