-continued  R  ~  CH3, C2Hs, C3H7, C4H9  X1  I  -----f CH2 -C-,-- OAO  \Si(OSiMe;)s  110  US 8,962,233 B2  109  tiator having an alkali soluble group to thereby introduce the  same in a polymer chain terminal.  The content of repeating units having an alkali soluble  group (x) is preferably in the range of 1 to 50 mo! %, more  preferably 3 to 35 mo!% and still more preferably 5 to 20 mo!  % based on all the repeating units of the polymer.  Specific examples of the repeating units having an alkali  soluble group (x) will be shown below, which however in no  way limit the scope of the present invention.  In the formulae, Rx represents H, CH$_{3}$ ,  CF$_{3 }$ or CH$_{2}$OH.  Moreover, the hydrophobic resin (HR) may have at least  one group selected from among the following groups (x) to  (z):  (x) an alkali soluble group,  (z) a group that is decomposed by the action of an acid.  As the alkali soluble group (x), there can be mentioned a  phenolic hydroxyl group, a carboxylate group, a fluoroalco› hol group, a sulfonate group, a sulfonamido group, a sulfa- nylimido group, an (alkylsulfonyl)(alkylcarbonyl)methylene  group, an (alkylsulfonyl)(alkylcarbonyl)imido group, a bis  (alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imido  group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfo› nyl)imido group, a tris(alkylcarbonyl)methylene group, a tris  (alkylsulfonyl)methylene group and the like.  (y) a group that is decomposed by the action of an alkali  developer, resulting in an increase of solubility in the alkali  developer, and  As preferred alkali soluble groups, there can be mentioned  a fluoroalcohol group (preferably hexafluoroisopropanol), a  sulfonimido group and a bis(carbonyl)methylene group.  As the repeating unit having an alkali soluble group (x),  preferred use is made of any of a repeating unit resulting from  direct bonding of an alkali soluble group to the principal chain  of a resin like a repeating unit of acrylic acid or methacrylic  acid, a repeating unit resulting from bonding, via a connect› ing group, of an alkali soluble group to the principal chain of  a resin and a repeating unit resulting from polymerization  with the use of a chain transfer agent or polymerization ini- Rx  I  -----f CH2 - C-,-- I  C=O  I  OH  Rx  I  -----f CH2 - C-,-- r=  O  COOR  OD  -q --+CH,-CH+- COOH  ¢  COOR  --+CH::r:,COOH -+CH;:r:› u  ~  COOR  -----fCHJ:› UOH  -----fCH::r:,OH -----fCH¢ 2 ;H-,-- u  ~I  SO3H 