US 2020/0192222 Al  20  Jun.  18,2020  -continued  n--(_/  cc,  r  ’i  ~  1 :&o;,V  O  ;  0  ~I  I  o~O  0  :_/  cc,  ~  0  0  I  I  (Aa)-2  (Aa)-1  (Ab)  (Aa)  [0066]  In formulae (A)-1 and (A)-2,  x+  is a sulfonium  cation having the formula (Aa) or ammonium cation having  the formula (Ab).  [0067]  In formula (Aa), R 6 , R 7  and R 8  are each indepen› dently fluorine, chlorine, bromine, iodine, or a C$_{1 }$-C$_{20 }$ monovalent hydrocarbon group which may contain a het› eroatom. R  6  and R  7  may bond together to form a ring with  the sulfur atom to which they are attached. The C$_{1 }$-C$_{20 }$ monovalent hydrocarbon group may be straight, branched or  [0070]  Examples of the sulfonium cation having formula  (Aa) are shown below, but not limited thereto.  [0069]  In formulae (Aa)-1 and (Aa)-2, R$^{13 }$to R$^{18 }$are each  independently a C$_{1 }$-C$_{14 }$ monovalent hydrocarbon group.  Examples of the monovalent hydrocarbon group include  C$_{1 }$-C$_{14 }$ alkyl,  C$_{2}$-C$_{14 }$ alkenyl,  CcC$_{14 }$ aryl, and  C$_{7}$-C$_{14 }$ aralkyl groups. In these groups, some or all hydrogen may  be substituted by hydroxyl, carboxyl, halogen, cyano, nitro,  sultone, sulfone, or sulfonium salt-containing moiety, or  some carbon may be replaced by ether bond, ester bond,  carbonyl, amide bond, carbonate or sulfonic ester bond. L is  a single bond, methylene, ether bond, thioether bond, or  carbonyl group. The subscripts z 1  to z 6  are each indepen› dently an integer of O to 5. Examples of the alkyl, alkenyl,  aryl and aralkyl groups are as exemplified above for R 5 •  [0068]  Preferred examples of the sulfonium cation having  formula (Aa) are those having the formulae (Aa)-1 and  (Aa)-2.  cyclic, and examples thereof include C$_{1 }$-C$_{20 }$ alkyl,  CcC$_{20 }$ aryl, and C$_{7}$ -C$_{20 }$aralkyl groups. In these groups, some or all  hydrogen may be substituted by hydroxyl, carboxyl, halo› gen, cyano, nitro, sultone, sulfone, or sulfonium salt-con› taining moiety, or an ether bond, ester bond, amide bond,  carbonyl moiety, carbonate moiety or sulfonate bond may  intervene between carbon atoms. 