US 9,513,547 B2  32  31  cyano group) and which does not exhibit acid decompos› ability is preferably 10 to 60 mo!% or more with respect to  all of the repeating units in the resin (A) and even more  preferably 20 to 50 mo! % from the viewpoint of sufficiently  decreasing the solubility with respect to the organic based 5  developer in the exposure portion while sufficiently main› taining the solubility of the unexposed portions and improv› ing the dissolution contrast and from the viewpoint of  imparting etching resistance.  In the present invention, the resin (A) may include only  one type of repeating unit represented by general formula  (1), and may include two or more types.  The content (in a case where a plurality of types are  contained, the total thereof) of the repeating unit represented  by the general formula (1) is preferably 70 mo! % or less  with respect to all of the repeating units in the resin (A),  more preferably 1 to 60 mo! %, and even more preferably 1  to 50 mo! %, and particularly preferably 1 to 40 mo! % from  the viewpoint of sufficiently decreasing the solubility with  respect to the organic based developer in the exposure  portion while sufficiently maintaining the solubility of the  unexposed portions and improving the dissolution contrast  and from the viewpoint of imparting etching resistance.  Other Repeating Units  The resin (A) may further have a repeating unit having a  lactone structure.  The resin (A) may or may not have a repeating unit having  a lactone structure resin (A); however, not having the  repeating unit is preferable in practice. More specifically, the  content of the repeating unit having a lactone structure in the  resin (A) is preferably 40 mo! % or less with respect to all  of the repeating units in the resin (A), more preferably 25  mo! % or less, even more preferably 10 mo! % or less,  ideally  O  mo! %, that is, not having a repeating unit having  a lactone structure is particularly preferable.  Below, specific examples of the repeating unit having a  lactone structure in resin (A) are shown; however, the  present invention is not limited thereto. In the formula, Rx  represents  H, CH$_{3}$ ,  CH$_{2}$0H,  or  CFy  [Chem. 21]  Rx  Rx  Rx  ~  ~~  &o  p  0  Rx  Rx  ~~  ~  LltCN  0  0  [Chem. 22]  Rx  Rx  ~  ~  Qf  Q(COOMe  0  0  Rx  $^{~ }$vt  0  -continued 