163  US 9,360,753 B2  164  Acid generator: PAGl of the following structural formula  ~~  0  0  0  0  ¢  ~o  OH  HN--{  0  Polymer 15  Mw~7,600  Mw/Mn~ 1.76  Positive resist compositions in solution form were pre- pared by dissolving a polymer (Polymers 1 to 15) and com- ponents in a solvent in accordance with the formulation of  Table 1 and filtering through a filter with a pore size of0.2 µm.  The solvent contained 100 ppm of surfactant FC-4430 ( com- mercially available from 3M). The components in Table 1 are  identified below.  Organic Solvents:  PGMEA (propylene glycol monomethyl ether acetate)  CyH (cyclohexanone)  CyP ( cyclopentanone)  PGME (propylene glycol monomethyl ether)  PGEE (propylene glycol monoethyl ether)  PGPE (propylene glycol monopropyl ether)  PAGl  9  0-s+  -6  0  Amine  1  0  o- Fe $^{3}$+  -continued  Basic compound: Amine 1 of the following structural formula  Metal compounds: the following structural formulae  2,4-pentadionatosodium  bis(2,4-pentadionato )magnesium  b is(2,2,6 ,6-tetrametbyl-3 ,5- heptanedionato)  chromiwn  tris (2 ,2 ,6 ,6-tetrametby 1-3 ,5- heptanedionato)  manganese  tris (2 ,2 ,6 ,6-tetrametby 1-3 ,5- heptanedionato)  iron  Mn $^{3}$+ 