US 2012/0003590 Al  62  Jan. 5, 2012  substituted. Examples of the substituent which the alkyl  group, cycloalkyl group, aryl group and electron-withdraw› ing group may have include a halogen atom, an alkoxy group  (for example, having a carbon number of 1 to 5), a hydroxyl  group, a cyano group and a nitro group.  [0336]  R$_{209 }$is preferably a substituted orunsubstituted aryl  group.  [0337]  R$_{210 }$ is preferably an electron-withdrawing group.  This electron-withdrawing group is preferably a cyano group  or a fluoroalkyl group.  [0338]  A represents an alkylene group, an alkenylene group  or an arylene group. These alkylene group, alkenylene group  and arylene group may have a substituent.  [0339]  Specific examples of the aryl group of Ar$_{3}$ ,  Ar$_{4}$ ,  R$_{208}$, R$_{209 }$and R$_{210 }$are the same as specific examples of the  aryl group as R$_{201}$ , R $_{202 }$and R$_{203 }$in formula (ZI-1).  [0340]  Specific examples of the alkyl group and cycloalkyl  group of R$_{208}$ , R 209  and R$_{210 }$ are the same as specific  examples of the alkyl group and cycloalkyl group as R$_{201}$,  R$_{202 }$and R$_{203 }$in formula (ZI-2).  [0341]  The alkylene group of A includes an alkylene group  having a carbon number of 1 to 12 (e.g., methylene group,  ethylene group, propylene group, isopropylene group, buty› lenes group, isobutylene group); the alkenylene group of A  includes an alkenylene group having a carbon number of 2 to  12 (e.g., ethynylene group, propenylene group, butenylene  group); and the arylene group of A includes an arylene group  having a carbon number of 6 to 10 (e.g., phenylene group,  tolylene group, naphthylene group).  [0342]  As the photo-acid generator, a compound having a  plurality of structures represented by formula (ZVI) is also  preferred. For example, the compound includes a compound  having a structure where R$_{209 }$or R$_{210 }$in a compound repre› sented by formula (ZVI) is bonded to R$_{209 }$or R$_{210 }$in another  compound represented by formula  (ZVI).  [0343]  The photo-acid generator is preferably a compound  represented by any of formulae  (ZI)  to  (ZIII),  more preferably  a compound represented by formula  (ZI).  [0344]  Specific examples of the photo-acid generator are  illustrated below, but the present invention is not limited  thereto.  (  Gs c,c-s~  3  B-1  B-2  3  B-3  B-4  -t-0-s.- C4F9-S03- - b  H 3 c-o-O-s  +  C4F9-S03- - b  B-5  B-6  (  +ors c,c,-so;  (Ys.  c,c,-s~  B-7  B-8  0-0-s+  C4F9-S03- - b 