16  US 8,283,102 B2  15  -continued  [Chemical formula 19]  [Chemical formula 20]  and  [Chemical formula 21]  wherein, a, b, c, d, and e may respectively satisfy 0.01 ~a/  (a+b+c+d+e)<0.4; 0.01 <b/(a+b+c+d+e)<0.3; 0.01 <c/(a+b+  c+d+e )<0.3; 0.01 ~d/(a+b+c+d+e )<0.3; 0.01 ~e/(a+b+c+d+  e)<0.15.  In addition, the chemically amplified resist composition  according to an exemplary embodiment of the invention may  include the copolymer and a solvent, and a main chain of the  copolymer is connected with the PAG. The chemically ampli- fled resist composition according to an exemplary embodi- ment of the invention may further include other additives. The  other additives are not particularly limited, however, for  example, a surfactant and water-soluble alcohols may be used  alone or in any combination thereof. The chemically ampli› fied resist composition according to an exemplary embodi› ment of the invention may further include a separate PAG. 