Jul.  18,  2019  68  US 2019/0219920 Al  -continued  -continued  (al0-1-41)  OH  (al0-1-44)  OH  OH  (al0-1-42)  OH  OH  (al0-1-43)  OH  [0663]  In the resist composition of the present embodi› ment, the resin component (Al’) contains a polymer having  the structural unit (a0) and the structural unit (al0). As the  component (Al’), 1 kind of the polymer may be used, or 2  or more kinds of the polymers may be used in combination.  [0662]  Examples of other structural units include a struc› tural unit (al) containing an acid decomposable group that  exhibits increased polarity by the action of acid, (provided  that the structural unit (a0) is excluded); a structural unit (a2)  containing a lactone-containing cyclic group, an -SO$_{2}$ - containing cyclic group or a carbonate-containing cyclic  group; a structural unit (a3) containing a polar group› containing aliphatic hydrocarbon group (provided that the  structural units (a0), (al) and (a2) are excluded); a structural  unit (a4) containing an acid non-dissociable aliphatic cyclic  group; and a structural unit derived from styrene or a  derivative thereof. The structural units (al), (a2), (a3), (a4)  and the structural unit derived from styrene or a derivative  thereof are the same as defined for the structural units (al),  (a2), (a3), (a4) and the structural unit derived from styrene  or a derivative thereof described above regarding the resist  composition of the first aspect.  [0661]  If desired, the component (Al’) may include, in  addition to the structural units (a0) and (al0), other struc› tural unit.  [0660]  Other Structural Units:  [0659]  When the amount of the structural unit (al0) is at  least as large as the lower limit of the above preferable  range, the sensitivity may be more reliably enhanced. On the  other hand, when the amount of the structural unit (al0) is  no more than the upper limit of the above-mentioned range,  a good balance may be reliably achieved with the other  structural units.  [0658]  When the component (Al’) includes the structural  unit (al0), the amount of the structural unit (al0) based on  the combined total of all structural units constituting the  component (Al’) (100 mo! % ) is preferably 20 to 70 mo! %,  more preferably 25 to 60 mo! %, still more preferably 30 to  50 mo! %, and most preferably 40 to 50 mo! %.  [0657]  As the structural unit (al0) contained in the com› ponent (Al’), 1 kind of structural unit may be used, or 2 or  more kinds of structural units may be used.  [Chemical Formula 62] 