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[0156] R$^{402 }$is a single bond or a C$_{1 }$-C$_{20 }$divalent linking group in case ofr=l, and a C$_{1}$-C$_{20 }$tri- or tetravalent linking group in case of r=2 or 3. The linking group may contain oxygen, sulfur or nitrogen. 

[0157] R11 to R11 $^{4 }$are each independently hydrogen, fluo› rine or trifluoromethyl, at least one thereof being fluorine or trifluoromethyl. Also R11 $^{1 }$and R11 2 , taken together, may form a carbonyl group. Most preferably both R11 1 and R11 2 are fluorine. 

[0158] R 403 , R 404 , R 405 , R $^{406 }$and R$^{407 }$are each indepen› dently a C$_{1 }$-C$_{20 }$monovalent hydrocarbon group which may contain a heteroatom. Any two ofR 403 , R $^{404 }$and R$^{405 }$may bond together to form a ring with the sulfur atom to which they are attached. The monovalent hydrocarbon group may be straight, branched or cyclic and examples thereof include C$_{1 }$-C$_{12 }$alkyl groups, C$_{2}$ -C$_{12 }$alkenyl groups, C$_{2}$ -C$_{12 }$alkynyl groups, CcC$_{20 }$ aryl groups, and C$_{7}$ -C$_{12 }$ aralkyl groups. In these groups, some or all hydrogen may be substituted by hydroxyl, carboxyl, halogen, cyano, amide, nitro, mercapto, sultone, sulfone, or sulfonium salt-containing moiety, or some carbon may be replaced by an ether bond, ester bond, carbonyl, carbonate or sulfonic acid ester bond. 

[0159] The subscript r is an integer of 1 to 3. The subscript sis an integer of 1 to 5, and tis an integer ofO to 3, meeting lss+ts5. Preferably, sis an integer of 1 to 3, more preferably 2 or 3, and t is an integer of O to 2. 

[0160] The cation moiety in the sulfonium salt having formula (3-1) is as exemplified above for the cation moiety in the sulfonium salt having formula (1-1 ). The cation moiety in the iodonium salt having formula (3-2) is as exemplified above for the cation moiety in the iodonium salt having formula (1-2). 

[0161] Examples of the anion moiety in the onium salts having formulae (3-1) and (3-2) are given below, but not limited thereto. Herein X is as defined above. 

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