22  21  US 9,423,690 B2  In Formula (1-0),  The alkyl group as Ri, R$_{2}$ ,  Ru to R$_{13 }$is preferably an alkyl  group having 1 to 10 carbon atoms, examples thereof  include a methyl group, an ethyl group, a propyl group, an  isopropyl group, an-butyl group, a sec-butyl group, at-butyl  group, a neopentyl group, a hexyl group, a 2-ethylhexyl  group, an octyl group, a dodecyl group and the like.  That is, the electron beam-sensitive or extreme ultraviolet  ray-sensitive resin composition relating to the present inven› tion may be used as an electron beam-sensitive or extreme  ultraviolet ray-sensitive resin composition for an organic  solvent development, which is used for development using  a developer containing an organic solvent. Here, the term,  for an organic solvent development refers to a use that is  used in a step of developing using a developer including at  least an organic solvent.  As such, the present invention relates to an electron  beam-sensitive or extreme ultraviolet ray-sensitive resin  composition provided in the pattern forming method of the  present invention.  It is preferred that the electron beam-sensitive or extreme  ultraviolet ray-sensitive resin composition of the present  invention is typically a resist composition and a negative  type resist composition (that is, a resist composition for an  organic solvent development), because a particularly good  effect may be obtained. In addition, the composition relating  to the present invention is typically a chemical amplification  resist composition.  The resin (A) has the repeating unit represented by the  following Formula (1-0), and the content of the repeating  unit represented by the following Formula (1-0) is 45 mo!%  or more based on the whole repeating units of the resin (A).  Because the above content is 45 mo! % or more, high  contrast (y value is high) may be achieved. In the case of  forming a fine isolated space pattern, resolution and space  width roughness may be improved, and in the case of  forming a fine hole pattern, high resolution, good EL,  uniformity of local pattern dimension may be achieved.  [1] Resin (A)  The repeating unit represented by the following Formula  (1-0) is the repeating unit having the structure protected by  the leaving group in which the carboxyl group as a polar  group is decomposed by the action of an acid and left, and  thus, the resin (A) is a resin in which the solubility to the  develop contacting an organic solvent may be reduced by the  action of an acid.  The alkyl group ofR$_{1 }$ and R$_{2 }$ is preferably an alkyl group  having 2 to 10 carbon atoms, more preferably, R$_{1 }$ and R$_{2 }$ both are an ethyl group, from the viewpoint of achieving the  effect of the present invention surely.  The alkyl group of Ru and R$_{12 }$is preferably alkyl group  having 1 to 6 carbon atoms, more preferably, a methyl group  or and ethyl group, and particularly preferably a methyl  group.  R$_{13 }$ is preferably a hydrogen atom or a methyl group.  Ru and R$_{12 }$ may be particularly preferably bound with  form an alkylene group and to from a ring, and Ru and R$_{13 }$ may be bound with from an alkylene group and then to form  a ring.  The ring which Ru and R$_{12 }$ are bound with form is  preferably a 3- to 8-membered ring, and more preferably a  5- to 6-membered ring.  The ring which Ru and R$_{13 }$ are bound with form is  preferably a 3- to 8-membered ring, and more preferably a  5- to 6-membered ring.  When Ru and R$_{13 }$ are bound with each other to form a  ring is preferably the when Ru and R$_{12 }$are bound with each  other to form a ring.  The ring formed by Ru and R$_{12 }$ (or Ru and R$_{13}$ ) being  bound with each other is more preferably an alicyclic group  described as X of Formula (1-1).  The alkyl group ofR$_{1}$ ,  R$_{2}$ ,  Ru to R$_{13}$, and the ring formed  by Ru and R$_{12 }$( or Ru and R 13 ) being bound with each other,  may further have a substituent.  Examples of the further substituent possessed by the alkyl  group ofR$_{1}$ , R 2 , Ru to R 13 , and the ring formed by Ru and  R$_{12 }$ (or Ru and R$_{13}$ ) being bound with each other may  include a cycloalkyl group, an aryl group, an amino group,  a hydroxyl group, a carboxyl group, a halogen atom, an  alkoxy group, an arakyloxy group, a thioether group, an acyl  group, an acyloxy group, an alkoxycarbonyl group, a cyano  group and a nitro group and the like. The substituents may  be bound with each other to form a ring. When the substitu› ents are bound with each other to form a ring, the ring  includes a cycloalkyl group or phenyl group having 3 to 10  carbon atoms.  The alkyl group of Ra may have a substituent, and is  preferably an alkyl group having 1 to 4 carbon atoms.  Preferred examples of the substituent which may be  possessed by the alkyl group of Ra may include a hydroxyl  group, and a halogen atom.  The halogen atom of Ra includes a fluorine atom, a  chlorine atom, a bromine atom, and an oxo atom.  Ra is preferably a hydrogen atom, a methyl group, a  hydroxymethyl group, a perfluoroalkyl group (for example,  trifluoromethyl group) having 1 to 4 carbon atoms, and  particularly preferably methyl group, from the viewpoint of  improving the glass transition temperature (Tg), the resolu› tion, and the space width roughness of resin (A).  But, if L$_{1 }$ is a phenylene group, Ra is preferably a  hydrogen atom.  The divalent linking group represented by L$_{1 }$ includes an  alkylene group, a divalent aromatic ring group, -COO› Lu-, -0-Lu -, a group in combination of two or more  thereof, and the like. Here, Lu represents an alkylene group,  R$_{1 }$ and R$_{2 }$ each independently represent an alkyl group,  Ru and R$_{12 }$ each independently represent an alkyl group,  and R$_{13 }$ represents a hydrogen atom or an alkyl group. Ru  and R$_{12 }$may be bound with each other to form a ring, and  Ru and R$_{13 }$may be bound with each other to form a ring.  Ra represents a hydrogen atom, an alkyl group, a cyano  group or a halogen atom, and L$_{1 }$ represents a single bond or  a divalent linking group.  In Formula (1-0), 