111  US 10,915,021 B2  112  Of the foregoing PAGs, those compounds having an anion  of formula (IA’) or (ID) are especially preferred because of  reduced acid diffusion and high solubility in resist solvent,  and those compounds having an anion of formula (2’) are  especially preferred because of minimized acid diffusion.  Also sulfonium and iodonium salts of iodized benzoy- loxy-containing fluorinated sulfonic acid having the formu› lae (3-1) and (3-2) are useful as the PAG.  -continued  F  F 