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 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. 711 811 

The cyclic saturated hydrocarbon group for R , R 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. 

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. 711 811 

Further, the saturated hydrocarbon group for R , R 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. 711 811 

The aliphatic unsaturated hydrocarbon group for R , R 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. 711 

Of the various possibilities described above, each of R , 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. 

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 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. 

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-. 

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- 

