Pattern-forming method and composition for resist pattern-refinement

Abstract

A pattern-forming method comprises forming a prepattern that is insoluble or hardly soluble in an organic solvent. A first composition is applied on at least lateral faces of the prepattern to fort i a resin layer. Adjacent regions to the prepattern of the resin layer are insolubilized or desolubilized in the organic solvent without being accompanied by an increase in a molecular weight by heating the prepattern and the resin layer. Regions other than the adjacent regions insolubilized or desolubilized of the resin layer are removed with the organic solvent. The first composition comprises a first polymer having a solubility in the organic solvent to be decreased by an action of an acid. At least one selected from the following features (i) and (ii) is satisfied: (i) the first polymer comprises a basic group; and (ii) the first composition further comprises a basic compound.

1 . A resist pattern-refinement composition, comprising
 a polymer comprising a basic group and having a solubility in an organic solvent to be decreased by an action of an acid.   
     
     
         2 . The resist pattern-refinement composition according to  claim 1 , wherein the polymer comprises a structural unit comprising an aromatic ring, and a proportion of the structural unit with respect to total structural units in the polymer is no less than 20 mol %. 
     
     
         3 . The resist pattern-refinement composition according to  claim 1 , wherein the polymer has a weight average molecular weight of no less than 13,000 and no greater than 150,000. 
     
     
         4 . A resist pattern-refinement composition, comprising
 a polymer having a solubility in an organic solvent to be decreased by an action of an acid; and   a basic compound.   
     
     
         5 . The resist pattern-refinement composition according to  claim 4 , wherein the polymer comprises a structural unit comprising an aromatic ring, and a proportion of the structural unit with respect to total structural units in the polymer is no less than 20 mol %. 
     
     
         6 . The resist pattern-refinement composition according to  claim 4 , wherein the polymer has a weight average molecular weight of no less than 13,000 and no greater than 150,000. 
     
     
         7 . A resist pattern-refinement composition, comprising a basic compound and an organic solvent, and not comprising a polymer having a solubility in an organic solvent to be decreased by an action of an acid. 
     
     
         8 . The resist pattern-refinement composition according to  claim 1 , wherein the polymer further comprises an acid-labile group. 
     
     
         9 . The resist pattern-refinement composition according to  claim 1 , wherein the basic group is a group represented by formula (a), a group represented by formula (b) or a combination thereof, 
       
         
           
           
               
               
           
         
         wherein, in the formula (b), L represents a single bond, a divalent chain hydrocarbon group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms; and R A  and R B  each independently represent a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or L and R A  optionally taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which L and R A  bond. 
       
     
     
         10 . The resist pattern-refinement composition according to  claim 1 , wherein the composition further comprises an acid incrementor. 
     
     
         11 . The resist pattern-refinement composition according to  claim 1 , wherein the polymer further comprises a hydroxy group, a carboxy group, an oxo group, a group comprising a lactone structure, a group comprising a cyclic carbonate structure, a group comprising a sultone structure, or a combination thereof. 
     
     
         12 . The resist pattern-refinement composition according to  claim 1 ,
 wherein the polymer further comprises:   an acid-labile group; and   a hydroxy group, a carboxy group, an oxo group, a group comprising a lactone structure, a group comprising a cyclic carbonate structure, a group comprising a sultone structure, or a combination thereof, and   wherein the basic group is a group represented by formula (a), a group represented by formula (b) or a combination thereof,   
       
         
           
           
               
               
           
         
         wherein, in the formula (b), L represents a single bond, a divalent chain hydrocarbon group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms; and R A  and R B  each independently represent a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or L and R A  optionally taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which L and R A  bond. 
       
     
     
         13 . The resist pattern-refinement composition according to  claim 4 , wherein the polymer comprises an acid-labile group. 
     
     
         14 . The resist pattern-refinement composition according to  claim 4 , wherein the basic compound is represented by formula (X), a compound represented by formula (Y) or a combination thereof, 
       
         
           
           
               
               
           
         
         wherein, in the formula (X), X +  represents a monovalent onium cation; and Y −  represents a monovalent carboxylate anion or a monovalent sulfonamide anion, and 
         in the formula (Y), R X , R Y  and R Z  each independently represent an unsubstituted, hydroxy-substituted or amino-substituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms or an unsubstituted, hydroxy-substituted or amino-substituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or at least two of R X , R Y  and R Z  taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which the at least two of R X , R Y  and R Z  bond and the rest of R X , R Y  and R Z  represents an unsubstituted, hydroxy-substituted or amino-substituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms or an unsubstituted, hydroxy-substituted substituted or amino-substituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. 
       
     
     
         15 . The resist pattern-refinement composition according to  claim 4 , wherein the composition further comprises an acid incrementor. 
     
     
         16 . The resist pattern-refinement composition according to  claim 4 , wherein the polymer comprises a hydroxy group, a carboxy group, an oxo group, a group comprising a lactone structure, a group comprising a cyclic carbonate structure, a group comprising a sultone structure, or a combination thereof. 
     
     
         17 . The resist pattern-refinement composition according to  claim 4 ,
 wherein the polymer comprises:   an acid-labile group; and   a hydroxy group, a carboxy group, an oxo group, a group comprising a lactone structure, a group comprising a cyclic carbonate structure, a group comprising a sultone structure, or a combination thereof, and   wherein the basic compound is represented by formula (X), a compound represented by formula (Y) or a combination thereof,   
       
         
           
           
               
               
           
         
         wherein, in the formula (X), X +  represents a monovalent onium cation; and Y −  represents a monovalent carboxylate anion or a monovalent sulfonamide anion, and 
         in the formula (Y), R X , R Y  and R Z  each independently represent an unsubstituted, hydroxy-substituted or amino-substituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms or an unsubstituted, hydroxy-substituted or amino-substituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or at least two of R X , R Y  and R Z  taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which the at least two of R X , R Y  and R Z  bond and the rest of R X , R Y  and R Z  represents an unsubstituted, hydroxy-substituted or amino-substituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms or an unsubstituted, hydroxy-substituted or amino-substituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.