Patent ID: 7449573

Claim:
A photosensitive compound which, upon irradiation with one of KrF excimer laser light, ArF excimer laser light, electron beam and EUV light, generates an acid represented by one of formulae (IA), (IB), (IC) and (I′): wherein A 1 represents a divalent connecting group; A 2 and A 3 each independently represents a single bond, an oxygen atom, or —N(Rx)-; Rx and Rx′ each independently represents a hydrogen atom, an aryl group, an alkyl group, or a cycloalkyl group; A 4 represents a single bond or —C(═O)—; A 5 represents an alkylene group or an arylene group; Ra′ represents an organic group, provided that Ra′ and Rx′ in formula (IA) are bonded to each other to form a ring; Ra″ represents an alkyl group, an aryl group, an aralkyl group, or an alkenyl group, provided that Ra″ in formula (IB) represents an aryl group having a substituent; n represents 2 or 3; n1 represents an integer of 1 to 10; n2 represents an integer of 0 to 10; Rb represents a connecting group having a valence of n; and when A 3 is —N(Rx)-, Rx may be bonded to Rb to form a ring.