9  US 10,781,276 B2  10  n$^{1 }$is an integer of 1 to 3, m$^{1 }$is an integer of Oto 4 when  n$^{1 }$is 1, m 1  is an integer ofO to 6 when n 1  is 2, and m$^{1 }$is 0  to 8 when n’ is 3.  Specific examples of the unit B are represented below.  In the formula (1 ), R  1 ,  Land Sp are the same as those in  the formula  (I).  The compounds represented by formulas  (VI) to (VIII) will be described later.  The polymer in an embodiment of the present invention  preferably further comprises a radical scavenger unit (here- inafter also referred to as "unit D") in addition to the units  A to C. The unit D is preferably a unit wherein a phenol  structure or a hindered amine structure bonds at any position  of the structure to the * portion of the formula (1 ).  The unit D is not limited as long as the unit D can stabilize  the radical generated by the unit A and the unit B, but  specific examples of the unit D is represented below.  (Unit D)  (Unit  C)  The polymer may include a unit C wherein at least one  compound represented by the general formulas (VI) to  (VIII) bonds at any position in the compound to the  * portion  of the following formula (1 ). When the polymer contains the  unit C the sensitivity to the particle beam or the electro- magnetic wave can be improved.  When the polymer contains the structure of the compound  represented by the general formula (VIII) as the unit C, x› of the onium salt which has high acidity such as BF $_{2}$ -,  PF $_{6}$ - or SbF $_{6}$ - is preferably selected. Thereby, the com- pound represented by the general formula (VIII) has an  especially high sensitizing effect.  [Chem. 7]  ~  ~  L’-.  Sp  L’-.  Sp  ~  ~  L’-.  Sp  L’-.  Sp  0  ~  ~  L’-.  Sp  L’-.  Sp  \  N  R 5  is any one selected from the group consisting of a  5  linear, branched or cyclic alkylene group which may have a  substituent, the alkylene group having 1 to 12 carbon atoms;  a linear, branched or cyclic alkyleneoxy group which may  have a substituent, the alkyleneoxy group having 1 to 12  carbon atoms; a linear, branched or cyclic alkenylene group  10  which may have a substituent, the alkenylene group having  1 to 12 carbon atoms; a linear, branched or cyclic alkenyle› neoxy group which may have a substituent, the alkenylene› oxy group having 1 to 12 carbon atoms; an arylene group  which may have a substituent, the arylene group having 6 to 15  14 carbon atoms; and a heteroarylene group which may have  a substituent, the heteroarylene group having 4 to 12 carbon  atoms.  [Chem. 8]  (1)  r  L’-.  Sp  /  ~  ~  L’-.  Sp  \  N  L’-.  Sp  -=  =- -continued 