Resist composition and patterning process

A resist composition comprising a base polymer, a quencher, and a sulfonium salt having the formula (A-1) or an iodonium salt having the formula (A-2):

• wherein R1 is a hydroxyl group, carboxyl group, fluorine, chlorine, bromine, amino group, or a straight, branched or cyclic C1-C20 alkyl, C1-C20 alkoxy, C2-C20 alkoxycarbonyl or C2-C20 acyloxy group which may contain fluorine, chlorine, bromine, hydroxyl, amino or alkoxy moiety, or —NR9—C(═O)—R10 or —NR9—C(═O)—O—R′°, R9 is hydrogen, or a straight, branched or cyclic C1-C6 alkyl group, R10 is a straight, branched or cyclic C1-C16 alkyl, straight, branched or cyclic C2-C16 alkenyl, or C6-C12 aryl group which may contain halogen, hydroxyl, alkoxy, acyl or acyloxy moiety,
• R2 is a single bond, or a divalent C1-C20 linking group which may contain oxygen, sulfur or nitrogen,
• Rf is fluorine or trifluoromethyl,
• R3, R4 and R5 are each independently fluorine, chlorine, bromine, iodine, C1-C12 straight, branched or cyclic alkyl group, C2-C12 straight, branched or cyclic alkenyl group, C6-C20 aryl group, or C7-C12 aralkyl or aryloxyalkyl group, at least one hydrogen in the foregoing groups being optionally substituted by hydroxyl, carboxyl, halogen, oxo, cyano, amide, nitro, sultone, sulfone, or sulfonium salt-containing moiety, or at least one carbon in the foregoing groups being optionally substituted by an ether, ester, carbonyl, carbonate or sulfonate moiety, or R3 and R4 may bond together to form a ring with the sulfur atom to which they are attached,
• R6 and R7 are each independently trifluoromethyl, a C6-C10 aryl group, C2-C6 alkenyl group, or C2-C6 alkynyl group, at least one hydrogen in the foregoing groups being optionally substituted by a halogen, trifluoromethyl, C1-C10 straight, branched or cyclic alkyl or alkoxy, hydroxyl, carboxyl, alkoxycarbonyl, nitro or cyano moiety,
• m is an integer of 1 to 5, n is an integer of 0 to 3, and p is an integer of 1 to 4.