377  US 9,323,150 B2  378  c+  represents a counter cation.  The counter cation is preferably an onium cation. More  particularly, as preferred examples thereof, there can be men› tioned a sulfonium cation described above as being expressed  by  s+  (R$_{201}$’)(R$_{202}$’)(R$_{203}$’) of general formula  (ZI)  and an  iodonium cation described above as being expressed by 1+  (R$_{204}$’)(R$_{205}$’) of general formula  (ZII)  in connection with  photoacid generators.  Non-limiting specific examples of the compounds (PA) are  given below.  (PA-1)  (PA-3)  0  0-s+  -03S(CF2)3S02-N8-N8--t- (PA-5)  (PA-7)  (PA-9)  (PA-2)  (PA-4)  (PA-6)  Q  0-s+  (PA-8)  (PA-10)  (PA-11)  H02C--O-s+  -03S(CF2)3S02-NC)----NQ 