When a repeating unit having a cyano group is further  added to the resin, the sensitivity of a composition containing  the resin can be further improved.  When a repeating unit having a lactone group is further  added to the resin, dissolution contrast in a developer con› taining an organic solvent can be further improved, by which  it also becomes possible to further improve the  dry  etching  resistance, coating stability and adhering property to sub› strate of the composition containing the resin.  As such a polar group, a group having the site represented,  for example, by N+ or s+ is exemplified.  The specific examples of partial structures that "polar  group" can contain are shown below.  ( 4) A Functional Group Having an Ionic Site  (3) A Functional Group Containing the Structure in which  Two Atoms Different in Electronegativity by 0.5 or More are  Bonded by a Double Bond or a Triple Bond  As such a polar group, a group containing the structure  represented, for example, by C  N, C=O, N=O, S=O or  C  N is exemplified.  96  95  US 9,170,489 B2  When a repeating unit having a group containing a lactone  structure having a cyano group is further added to the resin,  dissolution contrast in a developer containing an organic sol› vent can be further improved, by which it also becomes pos- sible to further improve the sensitivity,  dry  etching resistance,  coating stability and adhering property to substrate of the  composition containing the resin. In addition to the above, it  is possible for a single repeating unit to bear functions result› ing from each of the cyano group and the lactone group, thus  the degree of freedom of design of the resin can further be  increased.  When the polar group that repeating unit (b) has is an  alcoholic hydroxyl group, repeating unit (b) is preferably  represented by at least one formula selected from the group  consisting of the following formulae (I-1 H) to (I-1 OH), more  preferably represented by at least one formula selected from  the group consisting of formulae (I-lH) to (I-3H), and still  more preferably represented by formulae (I-lH).  -OH -COOR -C- -C-O- 11  II  0  0  -o-c-o- -CN  -NC  11  0  I  -C=N  \  I  -C-N  II  \  I  -O-C-N  II  \  I  ;  -N-C-N  II  \  0  0  -C-N-C- 11  I II  0  H  -N- 0  0  0  0  II  -NO  -S- Ii  0  0  II  /  II  -S- -S-N  -S-O- II  II  \  0  0  Ii  0  0  0  0  II  II  II  -S-N-S- -S-N-C- g  I  g  g  I  g  10  0  [  0  10  -y- x  -coo-y- /  -N0 0X  "  -s~ ex  [-coo 0  "Polar group" that repeating unit (b) can contain is prefer- ably at least one selected from the group consisting of (I) a  hydroxyl group, (II) a cyano group, (III) a lactone group, (IV)  a carboxylic acid group or a sulfonic acid group, (V) an amido  group, a sulfonamide group, or a group corresponding to the  derivative thereof, (VI) an ammonium group or a sulfonium  group, and a group obtained by combining two or more of  these groups.  (I-4H)  (I-3H)  (I-2H)  (1-lH) 