US 9,557,643 B2  86  85  2 or more, the dissolution contrast for an organic solvent› containing developer can be more enhanced and in turn, the  limiting resolution and roughness characteristics can be  more improved.  m is an integer of 1 or more. m is preferably an integer of  1 to 3, more preferably 1 or 2.  1 an integer of O or more. 1 is preferably O or 1.  p is an integer of  O  to 3.  Specific examples of the repeating unit having a group  capable of decomposing by the action of an acid to produce  an alcoholic hydroxy group are illustrated below. In specific  examples, Ra and OP have the same meanings as in formu› lae (I-1) to (I-3). In the case where a plurality of OP’s are  combined to form a ring, the corresponding ring structure is  denoted by "O-P---0" for the sake of convenience.  Ra  Ra  •:t  •:–:  06  d7  Af’oP  OP  OP  -continued 