50  US 8,900,791 B2  49  -continued  As the acid generator (A2), use can be made of a member  appropriately selected from among a photoinitiator for pho› tocationic polymerization, a photoinitiator for photoradical  polymerization, a photo-achromatic agent and photo-discol- oring agent for dyes, any of generally known compounds that  when exposed to actinic rays or radiation, generate an acid,  employed in microresists, etc., and mixtures thereof.  For example, as the acid generator, there can be mentioned  a diazonium salt, a phosphonium salt, a sulfonium salt, an  iodonium salt, an imide sulfonate, an oxime sulfonate, dia› zosulfone, disulfone or o-nitrobenzyl sulfonate.  Further, use can be made of compounds obtained by intro› ducing any of the above groups or compounds that when  exposed to actinic rays or radiation, generate an acid in a  polymer principal chain or side chain, for example, com› pounds described in U.S. Pat. No. 3,849,137, DE 3914407,  JP-A’ s-63-26653,  55-164824,  62-69263,  63-146038,  63-163452, 62-153853, 63-146029, etc.  Furthermore, use can be made of compounds that when  exposed to light, generate an acid described in U.S. Pat. No.  3,779,778 and EP 126,712.  As preferred compounds among the acid generators, there  can be mentioned those of the following general formulae  (ZI), (ZII)  and  (ZIII).  In the above general formula  (ZI),  each of R$_{201}$, R$_{202 }$and R$_{203 }$ independently represents an  organic group.  The number of carbon atoms of the organic group repre› sented by R$_{20}$i, R$_{202 }$and R$_{203 }$is generally in the range of 1 to  30, preferably 1 to 20.  Two of R$_{201 }$ to R$_{203 }$ may be bonded with each other to  thereby form a ring structure, and the ring within the same  may contain an oxygen atom, a sulfur atom, an ester bond, an  amido bond or a carbonyl group. As the group formed by  bonding of two of R$_{201 }$ to R$_{203}$ , there can be mentioned an  alkylene group (for example, a butylene group or a pentylene  group).  z- represents a normucleophilic anion.  As the normucleophilic anion represented by  z-,  there can  be mentioned, for example, a sulfonate anion, a carboxylate  anion, a sulfonylimido anion, a bis(alkylsulfonyl)imido  anion, a tris(alkylsulfonyl)methyl anion or the like.  The normucleophilic anion means an anion whose capa› bility of inducing a nucleophilic reaction is extremely low and  is an anion capable of inhibiting any temporal decomposition  by intramolecular nucleophilic reaction. This would realize  an enhancement of the temporal stability of the resist.  As the sulfonate anion, there can be mentioned, for  example, an aliphatic sulfonate anion, an aromatic sulfonate  anion, a camphor sulfonate anion or the like.  The photosensitive composition of the present invention  may contain, together with the acid generator (Al), another  acid generator. Hereinafter, the acid generator other than the  acid generator (Al) will be referred to as an "acid generator  (A2)."  [2] Compound that when Exposed to Actinic Rays or  Radiation, Generates an Acid (Acid Generator A2)  With respect to the counter cations, the conversion to  desired cation  M+  can be effected by, for example, a conver› sion method using an ion exchange resin or a generally known  anion exchange method as described in JP-A-6-184170, etc.  The compounds (Al) of the general formula  (I)  can be  synthesized by, for example, a method of sulfonating an aro› matic compound of cyclic aliphatic skeleton. For example,  the compounds substituted with a cycloalkyl group (Cy)  according to the present invention can be synthesized by the  following scheme.  The molecular weight of any of the compounds (Al) of the  general formula  (I)  is preferably in the range of 200 to 2000,  especially preferably 400 to 1000.  The total amount of compounds (Al) of the general for› mula  (I)  added, based on the total solid content of the photo› sensitive composition is preferably in the range of 0.1 to 40  mass %, more preferably 0.5 to 35 mass % and further pref› erably 3 to 30 mass%.  OH  lf  SY’)  S~OH  (A36)  ZI  z- ZII  z- ZIii  0  Alkyl halide  containing  alicyclic  group or  cycloalkene  Acid  ----- or  0  Sulfonation  (Cy)n  Base exchange  ~  (Cy)n 