Patent ID: 7527912

Claim:
A photoacid generator for chemically amplified resist compositions which generates a sulfonic acid upon exposure 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): RC(═O)R 1 —COOCH(CF 3 )CF 2 SO 3 − H + (1a) wherein R is selected from the group consisting of a hydroxyl group, a substituted or unsubstituted straight, branched or cyclic C 1 -C 20 alkyl group, a substituted or unsubstituted C 6 -C 15 aryl or C 4 -C 15 hetero-aryl group, a substituted or unsubstituted straight, branched or cyclic C 1 -C 20 alkoxy group, and a substituted or unsubstituted C 6 -C 15 aryloxy or C 4 -C 15 hetero-aryloxy group, R 1 is a divalent C 1 -C 20 organic group which may have a substituent group containing a heteroatom selected from oxygen, nitrogen and sulfur atoms, or R 1 may form at least one cyclic structure with R.