Oct. 21, 2010  14  US 2010/0266955 Al  [0164]  In the formulas shown below,  Ra  represents a hydro› gen atom, a methyl group or a trifluoromethyl group.  (al-1-1)  [Chemical Formula 17]  (al-2)  -continued  (al-3)  (al-1-2)  (al-4)  (al-1-3)  (al-1-4)  (al-1-5)  (al-1-6)  In the formulas, X’ represents a tertiary alkyl ester-type acid  dissociable, dissolution inhibiting group; Y represents a  lower alkyl group of 1 to 5 carbon atoms or an aliphatic cyclic  group; n represents an integer of 0 to 3; Y 2  represents a  divalent linking group ( excluding divalent hydrocarbon  groups which may have a substituent); R is the same as  defined above; and each ofR 1 ’  and R 2 ’  independently repre› sents a hydrogen atom or a lower alkyl group of 1 to 5 carbon  atoms.  [0160]  Examples of the tertiary alkyl ester-type acid disso› ciable, dissolution inhibiting group for X’ include the same  tertiary alkyl ester-type acid dissociable, dissolution inhibit› ing groups as those described above for X  1 .  [0161]  As R 1 ’, R 2 ’, n and Y are respectively the same as  defined for R  1 ’, R  2 ’, n and Yin general formula  (p  1) described  above in connection with the "acetal-type acid dissociable,  dissolution inhibiting group".  [0162]  As examples of Y 2 ,  the same groups as those  described above forY 2  in general formula (al-O-2) can be  given.  [0163]  Specific examples of structural units represented by  general formula (al-1) to (al-4) are shown below.  ; H 2  R}  c,..._I  C  I  O=C  \ $_{0 }$ I •  I  2•  R -C-R  I  $^{0 }$\---- CH2  f-.._:.,,  n  y  ; H2  R}  c,..._I  C  I  o=c  ’o  I  y2  I  o=c  I  X’  ; H 2  R}  c......._l  C  I  o=c  ’o  I  y2  I  O=C  ’o  I •  I  2•  R -C-R  I  $^{0 }$\---- CH2  f-.._:.,,  n  y 