US 2020/0192222 Al  2  Jun.  18,2020  [[ 9’RlN~R’,~1  A’  (A)-4  [  9’RlN’R’,,,  (A)-3  (A)-2  (A)-1  Herein R 1  is hydroxyl, fluorine, chlorine, bromine, amino,  nitro, cyano, or a C 1  -C 6  alkyl group, C 1  -C 6  alkoxy group,  C 2 -C 6  acyloxy group or C 1  -C 4  alkylsulfonyloxy group,  which may be substituted with halogen, or -NR  IA  ----C  (=O)-R 1$_{B}$ $_{or-NR}$1 A----C(=O)-O-R 1$_{B,}$ $_{R}$1 A is hydro› gen or a C 1  -C 6  alkyl group,  RIB  is a C 1  -C 6  alkyl group or  C 2 -C$_{8 }$ alkenyl group. R 2  is a single bond or a C 1  -C$_{20 }$divalent  linking group which may contain ether bond, carbonyl  moiety, ester bond, amide bond, sultone moiety, lactam  moiety, carbonate moiety, halogen, hydroxyl moiety or  carboxyl moiety. R 3  is a C 1  -C$_{10 }$alkyl group or CcC$_{10 }$aryl  group, which may be substituted with amino, nitro, cyano,  C 1  -C$_{12 }$ alkyl, C 1  -C$_{12 }$ alkoxy, C 2 -C$_{12 }$ alkoxycarbonyl,  C 2 -C$_{12 }$ acyl, C 2 -C$_{12 }$ acyloxy, hydroxyl or halogen. R 4  is a  C 1  -C$_{20 }$ divalent hydrocarbon group which may contain an  ester bond or ether bond. Rs is hydrogen, nitro, or a C 1  -C$_{20 }$ monovalent  hydrocarbon  group  which  may  contain  hydroxyl, carboxyl, ether bond, ester bond, thiol, nitro,  cyano, halogen or amino, with the proviso that in case of  p=l, groups Rs may bond together to form a ring with the  nitrogen atom to which they are attached, the ring optionally  containing a double bond, oxygen, sulfur or nitrogen; m is  an integer of  1  to 5, n is an integer of  O  to  4,  meeting  lsm+ns5, p is  1,  2 or 3, q is  1  or 2.  Aq- is a carboxylate  anion, fluorine-free sulfonimide anion, sulfonamide anion,  or halide ion.  x+  is a sulfonium cation having the formula  (Aa) or ammonium cation having the formula (Ab):  Herein  RA  is each independently hydrogen or methyl, R 21  is  a single bond or methylene, R 22  is hydrogen or a C 1 -C 4  alkyl  group, X 1  is a single bond, ether bond, ester bond, amide  bond, ----C(=O)---0-R 23 -, phenylene, -Ph-C(=O)› O-R24-, or -Ph-R 2 s-O----C(=O)-R 26 -, wherein Ph  stands for phenyl, R 23  is a C 1 -C$_{10 }$ alkanediyl group which  may contain an ether bond or ester bond, R 24 , R 2 s and R 26  are each independently a single bond or a C 1  -C 6  straight or  Herein R  6 , R  7  and R  8  are each independently fluorine,  chlorine, bromine, iodine, or a C 1  -C$_{20 }$ monovalent hydro› carbon group which may contain a heteroatom, R 6  and R 7  may bond together to form a ring with the sulfur atom to  which they are attached. R $^{9 }$to R  12  are each independently  hydrogen or a C 1  -C 24  monovalent hydrocarbon group which  may contain halogen, hydroxyl, carboxyl, thiol, ether bond,  ester bond, thioester bond, thionoester bond, dithioester  bond, amino, nitro, sulfone or ferrocenyl, R 9  and R $^{10 }$may  bond together to form a ring, R $^{9 }$and R  $^{10 }$taken together may  form =C(R $^{9}$A)(R  10 A),  R 9 A  and R  lOA  are each independently  hydrogen or a C 1  -C 16  monovalent hydrocarbon group,  R 9 A  and R  lOA  may bond together to form a ring with the carbon  and nitrogen atoms to which they are attached, the ring  optionally containing a double bond, oxygen, sulfur or  nitrogen.  [0024]  The resist composition may further comprise an  acid generator capable of generating sulfonic acid, imidic  acid or methide acid.  [0025]  In a preferred embodiment, the iodized base poly› mer comprises recurring units having the formula (al) or  recurring units having the formula (a2).  -continued  (Ab)  (Aa)  (al)  (a2) 