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where E comprises a strong electron-withdrawing substitu› ent, and in one embodiment this substituent comprises low photoabsorption cross-section in EUV, comprising the cyano group CN. However, the electron-withdrawing group is not limited to the cyano group (CN), but E can be the same or different. Other substituents, E, comprise an alkyl, alkyloxy, hydrogen, nitro, alkoxycarbonyl, halogen, aryl, aryloxy or aryloxycarbonyl group. These anions with low EUV absorp› tion are not limited to the anions 4, 5, 6 and 7; but could be anions of carboranes and other art-known anions as well that also exhibit low EUV absorption. R. P. Meagley, United States Patent Appl. 2005/0221220 gives examples of such carboranes. 

Disclosed anions A-, however, can also comprise aliphatic sulfonates, comprising perfluoroaliphatic sulfonates, substi› tuted or unsubstituted arylsulfonates, when used in conjunc- tion with a cation p+ that comprise atoms with high photoab› sorption cross-section in EUV light. 

PAGs p+ A- of the invention comprise cations p+, atoms with high photoabsorption cross-section in EUV, such as the above-mentioned sulfonium, selenium or iodonium cations comprising fluorine as substituents of the groups R$_{1}$ , R$_{2}$ , and/or R$_{3}$ , and of anions A- comprising atoms with low photoabsorption cross-section in EUV, comprise, e.g., such above-mentioned cyclic organic anions that are substituted with strong electron withdrawing groups, comprising e.g. CN. 

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II. Specifically, and in one embodiment, PAGs p+ A-, com- prise: 

1. p+ comprising; 

a) a sulfonium cation, comprising, 

b) a selenium cation, comprising; 

c) an iodonium cation, comprising, 

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and d), 

2. A- comprises the anion of a very strong acid, compris› ing: 

a), 

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