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4. A chemically amplified resist composition comprising 

(A) the sulfonium salt of claim 1, 2 or 3, 

(B) a polymer as a base resin, and 

(E) an organic solvent, 

said polymer comprising recurring units having the general formulae (2) and (3): 

-continued 

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wherein R 1 is hydrogen, fluorine, methyl or trifluorom› ethyl, Z is a single bond, phenylene, naphthylene or (backbone)-C(=O)---0-Z’-, Z’ is a straight C$_{1}$-C$_{10 }$ or branched or cyclic C$_{3}$-C$_{10 }$alkylene group which may contain a hydroxyl radical, ether bond, ester bond, or la ct one ring, or a pheny lene or naphthy lene group, XA is an acid labile group, andYL 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, sulfonate bond, carbonate bond, lac› tone ring, sultone ring, and carboxylic anhydride. 

5. The resist composition of claim 4 wherein the polymer further comprises recurring units (dl) or (d2) having the general formula: 

<img src='content_image/885127.jpg'>

wherein R1, R 2 , R 3 , and R 4 are as defined above, L’ is a single bond or C$_{2}$-C$_{5 }$ alkylene group, RY is a straight C$_{1}$-C$_{20 }$or branched or cyclic C$_{3}$ -C$_{20 }$monovalent hydro› carbon group which may be substituted with or sepa› rated by a heteroatom, A is hydrogen or trifluoromethyl, L" is a single bond or a straight C$_{1 }$-C$_{20 }$or branched or cyclic C$_{3}$-C$_{20 }$divalent hydrocarbon group which may be substituted with or separated by a heteroatom, n is 0 or 1, with the proviso that n is 0 when L" is a single bond. 

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