211  US 9,323,153 B2  212  -continued  [Chem. 45-2]  OH  In formulae, Rx represents H, CH$_{3}$_ CF $_{3 }$and CH$_{2}$OH.  Examples of the group (y) of which the degree of solubility  increases in an alkali developer include a lactone group, a  carboxylic ester group (--COO-), an anhydride group (---C  (O)OC(O)-), an acid imide group (-NHCONH-), a car› boxylic thioester group (-COS-), a carbonic ester group 55  (---OC(O)O-), a sulfuric ester group (-OSO$_{2}$O-), a sul› fonic ester group (-SO$_{2}$O-), or the like, and a lactone group  is preferable.  Specific examples of the repeating unit (by) having a group  capable of increasing the solubility in an alkali developer are  illustrated below, but the present invention is not limited  thereto. In addition, specific examples of the repeating unit  (A3) of the resin (Ab) can be also included as specific  examples of the repeating unit (by).  Ra represents a hydrogen atom, a fluorine atom, a methyl  group, or a trifluoromethyl group.  [Chem. 46-1]  Ra  :t  o---co .... ,o  0  ••-n  ’o  "--><  F  F  F  F 