Oct. 21, 2010  35  US 2010/0266955 Al  (a3-3)  -continued  [Chemical Formula 35]  (a4-1)  (a4-2)  (a4-3)  (a4-4)  In the formulas, R is the same as defined above; j is an integer  of 1 to 3; k is an integer of 1 to 3; t’ is an integer of 1 to 3; I is  an integer of 1 to 5; ands is an integer of 1 to 3.  [0214]  In formula (a3-l), j is preferably 1 or 2, and more  preferably  1.  When j is 2, it is preferable that the hydroxyl  groups be bonded to the 3rd and 5th positions of the adaman› tyl group. Whenj is 1, it is preferable that the hydroxyl group  be bonded to the 3rd position of the adamantyl group.  [0215]  j is preferably 1, and it is particularly desirable that  the hydroxyl group be bonded to the 3rd position of the  adamantyl group.  [0216]  In formula (a3-2), kis preferably  1.  Thecyano group  is preferably bonded to the 5th or 6th position of the norbomyl  group.  [0217]  In formula (a3-3), t’ is preferably 1.1 is preferably 1.  s is preferably  1.  Further, it is preferable that a 2-norbomyl  group or 3-norbornyl group be bonded to the terminal of the  carboxy group of the acrylic acid. The fluorinated alkyl alco› hol is preferably bonded to the 5th or 6th position of the  norbornyl group.  [0218]  As the structural unit (a3), one type of structural unit  may be used, or two or more types may be used in combina› tion.  [0219]  The amount of the structural unit (a3) within the  component (Al) based on the combined total of all structural  units constituting the component (Al) is preferably 5 to 50  mo! %, more preferably 5 to 40 mo! %, and still more pref› erably 5 to 25 mo!%. When the amount of the structural unit  (a3) is at least as large as the lower limit of the above-men› tioned range, the effect of using the structural unit ( a3) can be  satisfactorily achieved. On the other hand, when the amount  of the structural unit ( a3) is no more than the upper limit of the  above-mentioned range, a good balance can be achieved with  the other structural units.  [0220]  (Structural Unit (a4))  [0221]  The component (Al) may also have a structural unit  (a4) which is other than the above-mentioned structural units  (a0) and (al) to (a3), as long as the effects of the present  invention are not impaired.  [0222]  As the structural unit (a4), any other structural unit  which cannot be classified as one of the above structural units  (a0) and (al) to (a3) can, be used without any particular  limitation, and any of the multitude of conventional structural  units used within resist resins for ArF excimer lasers or KrF  excimer lasers (and particularly for ArF excimer lasers) can  be used.  [0223]  As the structural unit (a4), a structural unit derived  from an acrylate ester which contains a non-acid-dissociable  aliphatic polycyclic group is preferable. Examples of this  polycyclic group include the same groups as those described  above in relation to the aforementioned structural unit (al),  and any of the multitude of conventional polycyclic groups  used within the resin component of resist compositions for  ArF excimer lasers or KrF excimer lasers ( and particularly for  ArF excimer lasers) can be used.  [0224]  In consideration of industrial availability and the  like, at least one polycyclic group selected from amongst a  tricyclodecyl group, adamantyl group, tetracyclododecyl  group, isobomyl group, and norbornyl group is particularly  desirable. These polycyclic groups may be substituted with a  linear or branched alkyl group of 1 to 5 carbon atoms.  [0225]  Specific examples of the structural unit (a4) include  units with structures represented by general formulas (a4-1)  to (a4-5) shown below. 