US 2020/0209747 Al  45  Jul. 2, 2020  -continued  -continued  OH  OH  OH  I  OH  OH  RA  RA  RA  I  I  I  I  OH  OH  RA  &,  &OH  OH  OH  #  I  [0115]  Recurring units (dl) to (d3) have the function of  acid generator. The attachment of an acid generator to the  polymer main chain is effective in restraining acid diffusion,  thereby preventing a reduction of resolution due to blur by  acid diffusion. Also LWR is improved since the acid gen› erator is uniformly distributed. When a base polymer com› prising recurring units ( d) is used, an acid generator of  addition type (to be described later) may be omitted.  [0116]  The base polymer may further include recurring  units (e) which contain iodine, but not amino group.  Examples of the monomer from which recurring units ( e) are  derived are shown below, but not limited thereto.  RA  is as  defined above. 