22  US 9 104 101 B2  21  containing polycyclic groups in which one hydrogen atom  has been removed from a lactone ring-containing bicycloal› kane  tricycloalkane or tetracycloalkane.  In the latter case  examples of the substituent include the  same substituents as those described above for the linear or  branched saturated hydrocarbon group  and an alkyl group of  1  to 5 carbon atoms.  Further  the saturated hydrocarbon group for R  711   R  811  and  R 911  may be a combination of a linear or branched saturated  hydrocarbon group and a cyclic saturated hydrocarbon group.  Examples of combinations of a linear or branched satu› rated hydrocarbon group and a cyclic saturated hydrocarbon  group include groups in which a cyclic saturated hydrocarbon  group is bonded as a substituent to a linear or branched  saturated hydrocarbon group (such as a 1-(1-adamantyl)me› thyl group)  and groups in which a linear or branched satu› rated hydrocarbon group is bonded as a substituent to a cyclic  saturated hydrocarbon group.  The linear or branched saturated hydrocarbon group pref› erably contains  1  to 25 carbon atoms  more preferably  1  to 15  carbon atoms  and still more preferably  4  to  10  carbon atoms.  Examples of the linear saturated hydrocarbon group  include a methyl group  ethyl group  propyl group  butyl  group  pentyl group  hexyl group  heptyl group  octyl group   nonyl group and decyl group.  Examples of the branched saturated hydrocarbon group  include the tertiary alkyl groups mentioned above within the  description of R 56 . Further  other examples of the branched  saturated hydrocarbon group  excluding tertiary alkyl groups   include a 1-methylethyl group  1-methylpropyl group  2-me› thylpropyl group  1-methylbutyl group  2-methylbutyl group   3-methylbutyl group  1-ethylbutyl group  2-ethylbutyl group   1-methylpentyl group  2-methylpentyl group  3-methylpen› tyl group and 4-methylpentyl group.  The aliphatic unsaturated hydrocarbon group for R 711   R 811  and R$^{911 }$is preferably a linear or branched group. Examples of  the linear aliphatic unsaturated hydrocarbon group include a  vinyl group  propenyl group (ally! group)  and butynyl group.  Examples of the branched aliphatic unsaturated hydrocarbon  group include a 1-methylpropenyl group and 2-methylprope› nyl group. The linear or branched aliphatic unsaturated  hydrocarbon group may have a substituent. Examples of the  substituent include the same substituents as those described  above for the linear or branched saturated hydrocarbon group.  The alkoxy group as the substituent for the linear or  branched saturated hydrocarbon group is preferably an  alkoxy group having  1  to 5 carbon atoms  more preferably a  methoxy group  ethoxy group  n-propoxy group  iso-propoxy  group  n-butoxy group or tert-butoxy group  and most pref› erably a methoxy group or an ethoxy group.  Examples of the halogen atom as the substituent for the  linear or branched saturated hydrocarbon group include a  fluorine atom  chlorine atom  bromine atom and iodine atom   and a fluorine atom is preferable.  Examples of the halogenated alkyl group as the substituent  for the linear or branched saturated hydrocarbon group  include groups in which part or all of the hydrogen atoms  within an aforementioned linear or branched saturated hydro- carbon group have each been substituted with an aforemen› tioned halogen atom.  The cyclic saturated hydrocarbon group for R 711   R 811  and  R 911  preferably contains 3 to 20 carbon atoms. The cyclic  saturated hydrocarbon group may be either a polycyclic  group or a monocyclic group. Examples include groups in  which one hydrogen atom has been removed from a mono› cycloalkane  and groups in which one hydrogen atom has  been removed from a polycycloalkane such as a bicycloal› kane  tricycloalkane or tetracycloalkane. More specific  examples include groups in which one hydrogen atom has  been removed from a monocycloalkane such as cyclopen› tane  cyclohexane  cycloheptane or cyclooctane  and groups  in which one hydrogen atom has been removed from a poly› cycloalkane such as adamantane  norbomane  isobomane   tricyclodecane or tetracyclododecane.  The cyclic saturated hydrocarbon group may have a sub› stituent. For example  a portion of the carbon atoms that  constitute a ring within the cyclic saturated hydrocarbon  group may be substituted with a hetero atom  or a hydrogen  atom bonded to a ring within the cyclic saturated hydrocarbon  group may be substituted with a substituent.  Among the aforementioned non-aromatic divalent sub- stituents containing a hetero atom  a substituent that substi› tutes a portion of the carbon atoms that constitute the ring  structure of a cyclic alkyl group is preferably ---0-   ----C(=O)---O- -S- -S(=O)$_{2}$-or-S(=O)$_{2}$---0-.  Specific examples of cyclic alkyl groups having such a sub- Specific examples of the "non-aromatic divalent substitu› ent containing a hetero atom" that substitutes a portion of the  carbon  atoms  include  -0-   -C(=O)---0-   ----C(=O)-   ---0----C(=O)---O-   -C(=O)-NH-   -NH- (wherein H may be substituted with a substituent  such as an alkyl group or an acyl group)  -S-   -S(=O)$_{2}$ - and -S(=O)$_{2}$-O-.  Of the above non-aromatic substituents  examples of the  substituent that substitutes a portion of the carbon atoms that  constitute the alkyl group include non-aromatic divalent sub› stituents containing a hetero atom. There are no particular  limitations on the hetero atom in such substituents  provided  it is an atom other than a carbon atom or a hydrogen atom.  Examples of the hetero atom include a halogen atom  oxygen  atom  sulfur atom and nitrogen atom. Examples of the halo› gen atom include a fluorine atom  chlorine atom  iodine atom  and bromine atom. The substituent may consist solely of the  hetero atom  or may be a group that contains the hetero atom  and a group or atom other than the hetero atom.  Among the various possibilities described above  the non› aromatic substituent that substitutes a hydrogen atom of the  aforementioned alkyl group is preferably at least one sub› stituent selected from among an alkyl group  halogen atom   oxo group (=0)  alkoxyalkyloxy group  alkoxycarbonyla› lkyloxy group  ----C-(=O)---0-R 711   ---O-C(=O)-R 811  and-O-R 911 •  Of the various possibilities described above  each of R  711    R  811  and R 911  is preferably a hydrogen atom  a linear or  branched saturated hydrocarbon group of  1  to 15 carbon  atoms  or a cyclic saturated hydrocarbon group of 3 to 20  carbon atoms  as such groups yield superior lithography prop› erties and resist pattern shape. 