66  US 7,851,130 B2  65  -continued  It  is preferred for the alicyclic hydrocarbon-based acid- decomposable resin in the invention to have a repeating unit  having an alkali-soluble group, and it is more preferred to  have a repeating unit having a carboxyl group, by which the  resolution in the use for contact hole is enhanced. As the  repeating units having a carboxyl group, both a repeating unit  having a carboxyl group directly bonded to the main chain of  resin such as a repeating unit by acrylic acid or methacrylic  acid, and a repeating unit having a carboxyl group bonded to  the main chain of resin via a linking group are preferred, and  the linking group may have a monocyclic or polycyclic  hydrocarbon structure. The repeating unit by acrylic acid or  methacrylic acid is most preferred.  The alicyclic hydrocarbon-based acid-decomposable resin  in the invention may have a repeating unit having one to three  groups represented by the following formula (Fl), by which  line edge roughness property is improved.  In formula (Fl), R$_{50}$, R 5 i, $^{R}$52, R 53 , R $_{54 }$and R$_{55 }$ each  represents a hydrogen atom, a fluorine atom, or an alkyl  group, provided that at least any one ofR$_{50 }$to R$_{55 }$represents  a fluorine atom, or an alkyl group in which at least one  hydrogen atom is substituted with a fluorine atom.  Rx represents a hydrogen atom or an organic group (pref› erably an acid-decomposable protective group, an alkyl  group, a cycloalkyl group, an acyl group, or an alkoxycarbo- nyl group).  The alkyl group represented by R$_{50 }$to R$_{55 }$may be substi› tuted with a halogen atom, e.g., a fluorine atom, or a cyano  group, and preferably an alkyl group having from 1 to 3  carbon atoms, e.g., a methyl group and a trifluoromethyl  group can be exemplified.  It  is preferred that all of R$_{50 }$ to R$_{55 }$ represent a fluorine  atom.  As the organic group represented by Rx, an acid-decom- posable protective group, and an alkyl group, a cycloalkyl  group, an acyl group, an alkylcarbonyl group, an alkoxycar› bonyl group, an alkoxycarbonylmethyl group, an alkoxym› ethyl group, and a 1-alkoxyethyl group, each of which may  have a substituent, are preferred.  The repeating unit having the group represented by for- mula (Fl) is preferably a repeating unit represented by the  following formula (F2).  As the specific examples of the repeating units represented  by formula (VIII), the following compounds are exemplified,  but the invention is not restricted thereto.  In formula (VIII), Z$_{2}$ represents---O-or-N(R$_{41}$)-. R 41  represents a hydrogen atom, a hydroxyl group, an alkyl  group, or -OS0$_{2}$-R$_{42}$. R$_{42 }$represents an alkyl group, a  cycloalkyl group, or a camphor residue. The alkyl group  represented by R$_{41 }$and R$_{42 }$may be substituted with a halogen  atom (preferably a fluorine atom) and the like.  The alicyclic hydrocarbon-based acid-decomposable resin  in the invention may have a repeating unit represented by the  following formula (VIII).  (Fl)  (VIII)  ox:{o ox:{o ox:{o  H  I  OH  ~O  ~H  ~OH  ~OH  HO  HO 