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As the structural unit (a2L), it is preferable to use at least one structural unit selected from the group consisting of structural units represented by the aforementioned general formulas ( a2-1) to ( a2-5), more preferably at least one struc› tural unit selected from the group consisting of structural units represented by the aforementioned general formulas (a2-1) to (a2-3), and most preferably at least one structural unit selected from the group consisting of structural units represented by the aforementioned general formulas (a2-1) and (a2-3). 

Specifically, it is preferable to use at least one structural unit selected from the group consisting of formulas (a2-l-1) (a2-l-2) (a2-2-1 ), (a2-2-7), (a2-2-12), (a2-2-14), (a2-3-l) and (a2-3-5). 

Further, as the structural unit (a2L), a structural unit repre› sented by formula (a2-6) or (a2-7) shown below is also pref- erable. 

[Chemical Formula 69] 

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In the formulae, Rand R$^{29 }$are the same as defined above. 

In the polymeric compounds (Al) and (Al’), as the struc› tural unit (a2), one type of structural unit may be used, or two or more types may be used in combination. For example, as the structural unit (a2), a structural unit (a2s) may be used alone, or a structural unit (a2L), or a combination of these structural units may be used. 

Further, as the structural unit (a2s) or the structural unit (a2L), either a single type of structural unit may be used, or two or more types may be used in combination. 

In the polymeric compound (Al) or (Al’), the amount of the structural unit (a2) based on the combined total of all structural units constituting the polymeric compound (Al) or (Al’) is preferably 1 to 80 mo! %, more preferably 10 to 70 mo! %, still more preferably 10 to 65 mo! %, and most preferably 10 to 60 mo! %. 

When the amount of the structural unit (a2) is at least as large as the lower limit of the above-mentioned range, the effect of using the structural unit (a2) can be satisfactorily achieved. On the other hand, when the amount of the struc› tural unit (a2) is no more than the upper limit of the above› mentioned range, a good balance can be achieved with the other structural units, and various lithography properties such as DOF and CDU and pattern shape can be improved. 

## (Structural Unit (a3)) 

The structural unit (a3) is a structural unit containing a polar group. When the polymeric compound includes the structural unit (a3), the hydrophilicity of the polymeric com› pound is enhanced, thereby contributing to improvement in resolution. 

The structural unit (a3) is preferably a structural unit (a3- 12-21) derived from an acrylate ester which may have the hydrogen atom bonded to the carbon atom on the a-position substituted with a substituent and contains a polar group› containing aliphatic hydrocarbon group. 

Examples of the polar group include -OH, -COOH, ----CN, -SO$_{2}$NH$_{2}$ , ----CONH$_{2 }$ and a hydroxyalkyl group in which part of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms. Of these, -OH is preferable. 

The structural unit (a3) is preferably a structural unit con- taining a hydrocarbon group in which part of the hydrogen atoms has been substituted with a polar group. The hydrocar› bon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Among these, as the hydrocar- bon group, an aliphatic hydrocarbon group is preferable. 

Examples of the aliphatic hydrocarbon group as the hydro› carbon group include linear or branched hydrocarbon groups (preferably alkylene groups) of 1 to 10 carbon atoms, and aliphatic cyclic groups (monocyclic groups and polycyclic groups). 

These aliphatic cyclic groups (monocyclic groups and polycyclic groups) can be selected appropriately from the multitude of groups that have been proposed for the resins of 

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