Dec.  27,  2018  2  US 2018/0373148 Al  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 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; 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.  (bl)  (b2)  (dl)  ~  zl  I  R31_ 8 +_R32  M- (d2)  R33  I  +s-R34  I  R35  (d3)  R36  I  +s-R37  I  R3s  (a)  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, 