US 10,606,172 B2  83  84  PAG 1 to PAG 4 of the following structural formulae  Acid Generators:  Examples and Comparative Examples  Resist compositions were prepared by dissolving the  polymer and selected components in a solvent in accordance  with the recipe shown in Tables 1 and 2, and filtering  through a filter having a pore size of 0.2 µm. The solvent  contained 100 ppm of surfactant FC-4430 (3M). The com- ponents in Tables 1 and 2 are as identified below.  Organic Solvents:  PGMEA (propylene glycol monomethyl ether acetate)  GBL (y-butyrolactone)  CyH (cyclohexanone)  PGME (propylene glycol monomethyl ether)  Polymer 3  Mw~7,900  Mw/Mn~ 1.83  Polymer 2  Mw~ 8,100  Mw/Mn~ 1.65  PAGl  \-j  s  -0-o)--cc,  -03S-CF2  PAG2  H  PAG3  ~o  i\  "P)---cz,  I  ~~  ro  SOi  I  0 