20  US 8,652,712 B2  19  RTR$_{2}$ X+  wherein  x+  comprises a halogen and wherein Rl and  R$_{2 }$ comprise aliphatic or aromatic moieties optionally com› prising at least one substituent selected from halogen, alkyl,  alkyloxy, aryl, aryloxy, nitro, cyano, halogen-substituted  alkyl or halogen-substituted alkyloxy. The substituent  A- the photoacid generator comprises the anion of a carborane or  peracceptor-substituted organic anions, selected from at least  one compound comprising 4,5,6 or 7:  the general structure Ri, R$_{2}$ ,  R$_{3 }$ y+,  wherein R$_{1}$ ,  Rw  and R$_{3 }$ comprise aliphalic or aromatic moieties,  optionally comprising at least one substituent  selected from halogen, alkyl, alkyloxy, aryl, aryloxy,  nitro, cyano, halogen-substituted alkyl halogen-sub› stituted alkyloxy, fluorine, iodine, and  y+  comprises  0, Sor Se, or  wherein E comprises an electron-withdrawing group and the  ring-protonation eliminates aromaticity. The substituent E of  the photoacid generator comprises at least one of cyano (CN), 50  alkyl, alkyloxy, hydrogen, nitro, alkoxycarbonyl, halogen,  aryl, aryloxy or aryloxycarbonyl group, or atoms with low  EUV photoabsorption cross-sections according to FIG.  1.  Another aspect of the present invention comprises a process  of forming a patterned material feature on a substrate, the 55  process comprising:  c) providing a material surface on a substrate;  d) forming a photoresist layer over the material surface, the  photoresist comprising  (i) an acid-sensitive imaging polymer that is originally  insoluble in aqueous, alkaline developers, but becomes  soluble upon reaction with protons, with or without the  aid of heating;  A) an antenna group p+ comprising atoms with high 65  EUV photoabsorption cross-sections according to  FIG. 1 comprising an organic chalconium cation of  B) an antenna group p+ comprising an organic halonium  cation of the general structure RiR$_{2}$ X+,  wherein  FA  and R$_{2 }$ comprise aliphatic or aromatic moieties  optionally comprising at least one substituent  selected from halogen, alkyl, alkyloxy, aryl, aryloxy,  nitro, cyano, halogen-substituted alkyl or halogen› substituted alkyloxy, and  x+  comprises a halogen;  C)  an acid-forming group  A- comprising atoms with low  EUV photoabsorption cross-sections, comprised of, a  carborane or a peracceptor-substituted aromatic  anion, comprising at least one compound selected  from 4, 5, 6 or 7:  wherein E comprises at least one of cyano (CN), alkyl, alky› loxy, hydrogen, nitro, alkoxycarbonyl, halogen, aryl, aryloxy  or aryloxycarbonyl, alkylcarbonyloxy, arylcarbonyloxy or  atoms with low EUV photoabsorption cross-section accord› ing to FIG.  1.  (iii) a small amount of a base quencher;  (ii) a photoacid generator p+  A- comprising;  c) patternwise exposing the photoresist layer to radiation  thereby creating a pattern of radiation-exposed regions in the  photoresist layer;  E  F*F  E  E  4  E  E  E  E  E  E  E  E  E  E  E  E  E  E  E  E  E  7  E  F*F  E  E  E  E  E  E  E  E  E  E  E  E  E  E  7  E  E  E  E  E 