Photoresist composition

Abstract

A photoresist composition includes a base polymer, a polymer and an acid generator. The base polymer includes a first structural unit that includes an acid-labile group. The polymer includes a second structural unit that includes an acid-labile group, and has a fluorine atom content higher than a fluorine atom content of the base polymer. The photoresist composition is developed using an organic solvent. The second structural unit is represented by a formula (1) or a formula (2). R 1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 is a divalent monocyclic hydrocarbon group having 5 or 6 carbon atoms or a divalent polycyclic hydrocarbon group having 7 to 10 carbon atoms. R 2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 3 is an alicyclic hydrocarbon group having 5 to 20 carbon atoms.

1 . A photoresist composition comprising:
 a base polymer that includes a first structural unit that includes an acid-labile group;   a polymer that includes a second structural unit that includes an acid-labile group, and has a fluorine atom content higher than a fluorine atom content of the base polymer; and   an acid generator,   the photoresist composition being developed using an organic solvent,   the second structural unit being represented by a formula (1) or a formula (2),   
       
         
           
           
               
               
           
         
       
       wherein
 R 1  is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, 
 Z 1  is a divalent monocyclic hydrocarbon group having 5 or 6 carbon atoms or a divalent polycyclic hydrocarbon group having 7 to 10 carbon atoms, 
 R 2  is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and 
 R 3  is an alicyclic hydrocarbon group having 5 to 20 carbon atoms. 
 
     
     
         2 . The photoresist composition according to  claim 1 , wherein the first structural unit is a structural unit represented by a formula (3) or a formula (4), 
       
         
           
           
               
               
           
         
       
       wherein
 R 4  is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, 
 R 5  is an alkyl group having 1 to 5 carbon atoms, 
 n is 0 or 1, 
 R 6  is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, 
 R 7  is an alkyl group having 2 to 5 carbon atoms, and 
 Z 2  is a divalent monocyclic hydrocarbon group having 5 or 6 carbon atoms or a divalent polycyclic hydrocarbon group having 7 to 15 carbon atoms. 
 
     
     
         3 . The photoresist composition according to  claim 1 , wherein the polymer further includes a third structural unit represented by a formula (5), 
       
         
           
           
               
               
           
         
       
       wherein
 R 8  is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, 
 X is a linking group, and 
 R 9  is a linear or branched alkyl group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 4 to 20 carbon atoms, wherein some or all of the hydrogen atoms of the alkyl group or the alicyclic hydrocarbon group represented by R 9  are substituted with a substituent, at least one substituent that substitutes some or all of the hydrogen atoms of the alkyl group or the alicyclic hydrocarbon group represented by R 9  being a fluorine atom.