content_image/902913.jpg content_image/902914.jpg content_image/902911.jpg content_image/902912.jpg content_image/902908.jpg content_image/902909.jpg content_image/902910.jpg
<img src='content_image/902913.jpg'>

<img src='content_image/902914.jpg'>

wherein RA is hydrogen, fluorine, methyl or trifluorom› ethyl, zA is a single bond, phenylene group, naphthyl› ene group or (backbone)-C(=O)---0-Z’-, Z’ is a straight, branched or cyclic C$_{1 }$-C$_{10 }$ alkylene group which may contain a hydroxyl moiety, ether bond, ester bond or lactone ring, or phenylene group or naphthyl› ene group, XA is an acid labile group, and yA is hydrogen or a polar group having at least one structure selected from the group consisting of hydroxyl, cyano, carbonyl, carboxyl, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, lactone ring, sultone ring and carboxylic anhydride. 

8. The resist composition of claim 6, further comprising an organic solvent. 

9. The resist composition of claim 6, further comprising a photoacid generator other than the photoacid generator comprising the sulfonium compound of formula (I). 

10. The resist composition of claim 9 wherein the other photoacid generator has the formula ( 4) or (5): 

<img src='content_image/902911.jpg'>

wherein R 101 , R 102 and R 103 are each independently a straight, branched or cyclic C$_{1 }$-C$_{20 }$monovalent hydro› carbon group which may contain a heteroatom, any two ofR 101 , R $^{102 }$and R $^{103 }$may bond together to form a ring with the sulfur atom to which they are attached, and x› is an anion selected from the formulae (4A) to (4D): 

<img src='content_image/902912.jpg'>

(4A) 

<img src='content_image/902908.jpg'>

<img src='content_image/902909.jpg'>

wherein R: 1 \ R:11’1, R:11’ 2 , R’c1, R’c 2 and R’c3 are each independently fluorine or a straight, branched or cyclic C$_{1 }$-C$_{40 }$ monovalent hydrocarbon group which may contain a heteroatom, or a pair ofR:11’$^{1 }$and R:11’ 2 , or R’c1 and R’c 2 may bond together to form a ring with the carbon atom to which they are attached and any inter› vening atoms, R’d is a straight, branched or cyclic C$_{1 }$-C$_{40 }$ monovalent hydrocarbon group which may contain a heteroatom, 

<img src='content_image/902910.jpg'>

wherein R 121 , R 122 and R 123 are each independently a straight, branched or cyclic C$_{1 }$-C$_{20 }$alkyl group, Lis a single bond, ether bond, or a straight, branched or cyclic C$_{1 }$-C$_{20 }$ divalent hydrocarbon group which may contain a heteroatom, X1, X 2 , X 3 and X 4 are each independently hydrogen, fluorine or trifluoromethyl, at least one of X1, X 2 , X 3 and X 4 is fluorine or trifluo› romethyl, pl and p2 are each independently an integer of 0 to 5, and p3 is an integer of Oto 4. 

11. The resist composition of claim 6, further comprising an onium salt having the formula (6) or (7): 

wherein R$^{151 }$and R$^{152 }$are each independently hydrogen or a straight, branched or cyclic C$_{1 }$-C$_{40 }$ monovalent hydrocarbon group which may contain a heteroatom, exclusive of hydrocarbon groups in which the hydrogen atom in bond with the carbon atom at a-position relative to the sulfa group is replaced by a fluorine atom or fluoroalkyl moiety, and M+ is an onium cation. 

-continued 

(6) 

(7) 

