(meth)acrylate derivative, polymer and photoresist composition having lactone structure, and method for forming pattern by using it

Abstract

Photoresist material for lithography using a light of 220 nm or less comprising at least a polymer represented by following formula (2) and a photo-acid generator for generating an acid by exposure: wherein R 1 , R 2 , R 3 and R 5 , each a hydrogen atom or a methyl group; R 4 , an acid-labile group or one of a specified subset of alicyclic hydrocarbon groups, alicyclic hydrocarbon groups, or hydrocarbon groups; R 6 , a hydrogen atom, a specified subset of hydrocarbon groups or alicyclic hydrocarbon groups; x, y and z are optional values which meet x+y+z=1, 0<x≦1, 0≦y<1 and 0≦z<1; resin having a (meth)acrylate unit of an alicyclic lactone structure represented by formula (3): wherein R 8 , a hydrogen atom or a methyl group, and R 9 , one of a specified subset of hydrocarbon groups.

1 .- 4 . (canceled) 
     
     
         5 . A photoresist material comprising:
 a polymer which is represented by the formula (2) and has a weight-average molecular weight of 2000 to 200000; and   
       
         
           
           
               
               
           
         
         a photo-acid generator for generating an acid by exposure, 
       
       wherein R 1 , R 2 , R 3  and R 5  are each a hydrogen atom or a methyl group; R 4  is an acid-labile group, an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has an acid•labile group, an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has a carboxyl group, or a hydrocarbon group having 3 to 13 carbon atoms, which has an epoxy group; R 6  is a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 7 to 13 carbon atoms, which has a carboxyl group; and x, y and z are optional values which meet x+y+z=1, 0<x≦1, 0≦y<1 and 0≦z<1, 
       wherein said photo-acid generator for generating an acid by exposure comprises derivatives of triphenylsulfonium salts. 
     
     
         6 . The photoresist material according to  claim 5 ,
 said photo-acid generator for generating an acid by exposure is triphenylsulfonium triflate.   
     
     
         7 . A photoresist material comprising:
 a polymer; and   a photo-acid generator for generating an acid by exposure,   
       wherein said polymer which is obtained by polymerizing a (meth)acrylate derivative or by copolymerizing a (meth)acrylate derivative with another polymerizable compound, and has a weight-average molecular weight of 2000 to 200000, 
       wherein said (meth)acrylate derivative has an alicyclic lactone structure which is represented by the formula (4): 
       
         
           
           
               
               
           
         
       
       wherein R 8  is a hydrogen atom or a methyl group; R 9  is a hydrocarbon group of 7 to 16 carbon atoms having an alicyclic lactone structure, 
       wherein said photo-acid generator for generating an acid by exposure comprises derivatives of triphenylsulfonium salts. 
     
     
         8 . The photoresist material according to  claim 7 ,
 said photo-acid generator for generating an acid by exposure is triphenylsulfonium triflate.