content_image/907777.jpg content_image/907772.jpg content_image/907773.jpg content_image/907774.jpg content_image/907775.jpg content_image/907776.jpg
Herein RA is hydrogen or methyl, R 1 is hydrogen or an acid labile group, R 2 is a C 1 -C$_{6 }$ straight, branched or cyclic alkyl group or halogen other than bromine, X 1 is a single bond, phenylene group, or a C 1 -C$_{12 }$ straight, branched or cyclic alkylene group which may contain an ester moiety or lactone ring, X 2 is ---0-, -O----CH 2 - or -NH-, m is an integer of 1 to 4, preferably 2 to 4, and n is an integer of Oto 3. [0017] The polymer may further comprise recurring units having a group capable of polarity switch under the action of acid. The polarity switch under the action of acid takes place by elimination reaction. [0018] Preferably the recurring units having a group capable of polarity switch under the action of acid have the formula (bl) or (b2). 

Herein RA is each independently hydrogen or methyl, R 11 and R 12 are each independently an acid labile group, R 13 is fluorine, trifluoromethyl, cyano, a C 1 -C$_{6 }$ straight, branched or cyclic alkyl or alkoxy group, or a C 2 -C$_{7 }$ straight, branched or cyclic acyl, acyloxy or alkoxycarbonyl group, R 14 is a single bond or a C 1 -C$_{6 }$ straight or branched alkylene group in which at least one carbon atom may be substituted by an ether or ester moiety, p is 1 or 2, q is an integer of O to 4, Y 1 is a single bond, phenylene group, naphthylene group, or a C 1 -C$_{12 }$ linking group which may contain an ester moiety, ether moiety or lactone ring, and Y 2 is a single bond, -C(=O)---0- or ----C(=O)-NH-. 

[0019] The polymer may further comprise recurring units having an adhesive group selected from among hydroxyl, 

<img src='content_image/907777.jpg'>

<img src='content_image/907772.jpg'>

<img src='content_image/907773.jpg'>

carboxyl, lactone ring, carbonate, thiocarbonate, carbonyl, cyclic acetal, ether, ester, sulfonic acid ester, cyano, amide, and -O----C(=O)-G- wherein G is -S- or -NH-. [0020] The polymer may further comprise recurring units of at least one type selected from the formulae ( dl) to ( d3). 

Herein RA is each independently hydrogen or methyl; Z 1 is a single bond, phenylene group, ---O-Z 12 -, or ----C(=O)-Z 11 -, Z 12 -, Z $^{11 }$is ---0- or -NH-, Z 12 is a C 1 -C$_{6 }$ straight, branched or cyclic alkylene group, C 2 -C$_{6 }$ straight, branched or cyclic alkenylene group, or phenylene group, which may contain a carbonyl, ester, ether or hydroxyl moiety; R 31 to R 38 are each independently a C 1 -C$_{12 }$ straight, branched or cyclic alkyl group which may contain a carbonyl, ester or ether moiety, or a CcC$_{12 }$ aryl group or C$_{7}$ -C$_{20 }$aralkyl group, in which at least one hydro› gen may be substituted by a C 1 -C$_{10 }$ straight, branched or cyclic alkyl moiety, halogen, trifluoromethyl, cyano, nitro, hydroxyl, mercapto, C 1 -C$_{10 }$ straight, branched or cyclic alkoxy moiety, C 2 -C$_{10 }$ straight, branched or cyclic alkoxy› carbonyl moiety, or C 2 -C$_{10 }$ straight, branched or cyclic acyloxy moiety; Z 2 is a single bond, a C 1 -C$_{12 }$ straight, branched or cyclic alkylene group or C 2 -C$_{12 }$ straight, branched or cyclic alkenylene group which may contain an ether moiety, ester moiety or lactone ring, or C$_{6}$-C$_{10 }$arylene group; Z 3 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, ---O-Z 32 -, or ----C(=O)-Z 31 - Z32 -, Z $^{31 }$is ---0- or -NH-, Z 32 is a straight, branched or cyclic C 1 -C$_{12 }$ alkylene or C 2 -C$_{12 }$ alkenylene group which may contain a carbonyl, ester or ether moiety, or phenylene group, in which at least one hydrogen atom may be substi› tuted by fluorine or hydroxyl; and M- is a non-nucleophilic counter ion. 

[0021] The resist composition may further comprise an organic solvent, acid generator, basic compound, and/or surfactant. 

<img src='content_image/907774.jpg'>

<img src='content_image/907775.jpg'>

<img src='content_image/907776.jpg'>

