4  US 8,900,791 B2  3  (15) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (5) above, wherein the resin  (B) contains at least one repeating unit selected from among  2-alkyl-2-adamantyl (meth)acrylates and dialkyl(l-adaman- tyl)methyl (meth)acrylates, at least one repeating unit having  a lactone structure and at least one repeating unit having two  or more hydroxyl groups.  n is an integer of 1 or greater.  A represents any one, or a combination of two or more  members selected from a single bond, an alkylene group,  -0-,  -S-, -C(=0)-, -S(=0)-, -S(=0)$_{2}$-and  -0S(=0)$_{2}$ -,  provided that ----C(=0)0- is excluded.  B represents a group containing a hydrocarbon group hav› ing 4 or more carbon atoms wherein either a tertiary or a  quaternary carbon atom is contained.  Whennis 2 or greater, the two or more -(A-B) groups may  be identical to or different from each other.  M+  represents an organic onium ion.  (2) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (1) above, wherein in the  general formula  (I), B represents a cycloaliphatic group hav› ing 4 or more carbon atoms.  (16) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (15) above, wherein the resin  (B) further contains a carboxylated repeating unit.  (17) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (5) above, wherein the resin  (B) contains at least one repeating unit selected from among  2-alkyl-2-adamantyl (meth)acrylates and dialkyl(l-adaman- tyl)methyl (meth)acrylates and at least one repeating unit  having a hydroxystyrene structure.  (18) A method of forming a pattern, comprising the steps of  forming the actinic ray-sensitive or radiation-sensitive resin  composition according to any of items (1) to (17) above into  a film, exposing the film and developing the exposed film.  (19) The method of forming a pattern according to item  (18) above, wherein the exposure is carried out by use of  X-rays, electron beams or EUV.  (20) A compound of general formula  (I) below.  (3) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (1) or (2) above, characterized  by further containing a resin (B) that is decomposed by the  action of an acid to thereby exhibit an increased solubility in  an alkali developer.  (5) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (3) above, wherein the resin  (B) contains a repeating unit having a hydroxystyrene struc› ture.  (6) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (3) above, wherein the resin  (B) contains a repeating unit having a cyclic hydrocarbon  structure of a single ring or multiple rings.  (8) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (7) above, wherein the repeat› ing unit having an alcoholic hydroxyl group of the resin (B) is  a repeating unit having at least one member selected from  among a monohydroxyadamantane structure, a dihydroxy› adamantane structure and a trihydroxyadamantane structure.  In the formula,  Ar represents an aromatic ring that may have a substituent  other than the -(A-B) groups, and  n is an integer of 1 or greater.  A represents any one, or a combination of two or more  members selected from among a single bond, an alkylene  group,  ---0-,  -S-,  ----C(=0)-,  -S(=0)-,  -S(=0)$_{2}$ - and ---OS(=0)$_{2}$ - (provided that -C(=0)  0- is excluded).  B represents a group containing a hydrocarbon group hav- ing 4 or more carbon atoms wherein either a tertiary or a  quaternary carbon atom is contained.  Whennis 2 or greater, the two or more -(A-B) groups may  be identical to or different from each other.  M+  represents an organic onium ion.  (21) A compound of general formula  (I) below that when  exposed to actinic rays or radiation, generates an acid.  In the formula,  Ar represents an aromatic ring that may have a substituent  other than the -(A-B) groups, and  n is an integer of 1 or greater.  A represents any one, or a combination of two or more  members selected from among a single bond, an alkylene  (14) The actinic ray-sensitive or radiation-sensitive resin  composition according to any of items (5) to (13) above,  further containing a basic compound (F) and/or a fluorinated  and/or siliconized surfactant (G).  (13) The actinic ray-sensitive or radiation-sensitive resin  composition according to any of items (5) to (12) above,  further containing a dissolution inhibiting compound of3000 60  or less molecular weight (E) that is decomposed by the action  of an acid to thereby increase the solubility in an alkali devel› oper.  (12) The actinic ray-sensitive or radiation-sensitive resin 55  composition according to item (3) above, characterized in  that the resin (B) has a hexafluoro-2-propanol structure.  (11) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (3) above, wherein the resin  (B) has a fluorine atom in its principal chain or side chain.  (10) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (3) above, wherein the resin  (B) is a resin containing at least one methacrylic ester repeat- ing unit or at least one acrylic ester repeating unit.  (9) The actinic ray-sensitive or radiation-sensitive resin  composition according to item (3) above, wherein the resin  (B) contains a repeating unit having a lactone structure.  (I)  ~(A-B), M’  (I) 