Resist underlayer film forming composition for lithography, containing aromatic fused ring-containing resin

Abstract

There is provided a resist underlayer film forming composition for lithography, which in order to prevent a resist pattern from collapsing after development in accordance with the miniaturization of the resist pattern, is applied to multilayer film process by a thin film resist, has a lower dry etching rate than resists and semiconductor substrates, and has a satisfactory etching resistance relative to a substrate to be processed in the processing of the substrate. A resist underlayer film forming composition used in lithography process by a multiplayer film, comprises a polymer containing a unit structure having an aromatic fused ring, a unit structure having a protected carboxyl group or a unit structure having an oxy ring. A method of forming a pattern by use of the resist underlayer film forming composition. A method of manufacturing a semiconductor device by utilizing the method of forming a pattern.

1 . A resist underlayer film forming composition used in a lithography process for producing a semiconductor device comprising:
 a polymer containing at least one type of a unit structure selected from a group consisting of unit structures represented by Formula (1), Formula (2) and Formula (3):   
     
       
         
         
             
             
         
       
     
     (where
 X represents a hydrogen atom or an aromatic fused ring, 
 Y represents an aromatic fused ring, and X and Y may be bonded to each other to form a fused ring, 
 R 1 , R 2 , R 3 , R 4 , R 5 , R 10 , R 11  and R 12  individually represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 3 carbon atom, 
 R 6 , R 7  and R 8  individually represent a hydrogen atom or a chained or cyclic alkyl group having 1 to 10 carbon atom, 
 R 9  represents a chained or cyclic alkyl group having 1 to 10 carbon atom or an aromatic group having 6 to 20 carbon atoms, 
 R 7  and R 8  may be bonded to each other to form a ring, 
 M and Q individually represent a direct bond or a linking group, and 
 n represents an integer of 0 or 1), or a combination of more than one such polymer, in which when a total number of all unit structures constituting the polymer is assumed to be 1.0, a ratio of a number (a) of a unit structure represented by Formula (1), a ratio of a number (b) of a unit structure represented by Formula (2) and a ratio of a number (c) of a unit structure represented by Formula (3) satisfy 0.3≦a≦0.95, 0.005≦b≦0.7, 0≦c≦0.45. 
 
   
   
       2 . A resist underlayer film forming composition used in a lithography process for producing a semiconductor device comprising:
 a polymer containing unit structures represented by Formula (1) and Formula (2) as described in  claim 1 , in which when a total number of all unit structures constituting the polymer is assumed to be 1.0, a ratio of a number (a) of a unit structure represented by Formula (1) and a ratio of a number (b) of a unit structure represented by Formula (2) satisfy 0.305≦a+b≦1, 0.3≦a≦0.95, 0.005≦b≦0.7; and   a compound having an oxy ring represented by Formula (4):   
     
       
         
         
             
             
         
       
     
     (where n represents an integer of 0 or 1). 
   
   
       3 . A resist underlayer film forming composition used in a lithography process for producing a semiconductor device comprising:
 a polymer containing unit structures represented by Formula (1) and Formula (3) as described in  claim 1 , in which when a total number of all unit structures constituting the polymer is assumed to be 1.0, a ratio of a number (a) of a unit structure represented by Formula (1) and a ratio of a number (c) of a unit structure represented by Formula (3) satisfy 0.35≦a+c≦1, 0.3≦a≦0.95, 0.05≦c≦0.7; and   a compound having a protected carboxyl group represented by Formula (5):   
     
       
         
         
             
             
         
       
     
     (where
 R 6 , R 7  and R 8  individually represent a hydrogen atom or a chained or cyclic alkyl group having 1 to 10 carbon atom, 
 R 9  represents a chained or cyclic alkyl group having 1 to 10 carbon atom or an aromatic group having 6 to 20 carbon atoms, and 
 R 7  and R 8  may be bonded to each other to form a ring). 
 
   
   
       4 . A resist underlayer film forming composition used in a lithography process for producing a semiconductor device comprising:
 a polymer containing unit structures represented by Formula (1), Formula (2) and Formula (3) as described in  claim 1 , in which when a total number of all unit structures constituting the polymer is assumed to be 1.0, a ratio of a number (a) of a unit structure represented by Formula (1), a ratio of a number (b) of a unit structure represented by Formula (2) and a ratio of a number (c) of a unit structure represented by Formula (3) satisfy 0.355≦a+b+c≦1, 0.3≦a≦0.9, 0.005≦b≦0.65, 0.05≦c≦0.65.   
   
   
       5 . The resist underlayer film forming composition according to  claim 1 , wherein the unit structure represented by Formula (1) as described in  claim 1  is a unit structure containing vinyl naphthalene, acenaphthylene, vinyl anthracene, vinyl carbazole or a derivative thereof. 
   
   
       6 . A resist underlayer film obtained by applying the resist underlayer film forming composition as described in  claim 1  on a semiconductor substrate and by calcining the composition. 
   
   
       7 . A method of forming a resist pattern used in production of a semiconductor comprising:
 applying the resist underlayer film forming composition as described in  claim 1  on a semiconductor substrate; and   calcining the composition to form an underlayer film.   
   
   
       8 . A method of manufacturing a semiconductor device comprising:
 (1) forming an underlayer film on a semiconductor substrate by using the resist underlayer film forming composition as described in  claim 1 ;   (2) forming a resist film on the underlayer film;   (3) forming a resist pattern by irradiating light or an electron ray and by developing the pattern;   (4) etching the underlayer film with the resist pattern; and   (5) processing the semiconductor substrate with the patterned underlayer film.   
   
   
       9 . A method of manufacturing a semiconductor device comprising:
 (1) forming an underlayer film on a semiconductor substrate by using the resist underlayer film forming composition as described in  claim 1 ;   (2) forming a hard mask on the underlayer film;   (3) further forming a resist film on the hard mask;   (4) forming a resist pattern by irradiating light or an electron ray and by developing the pattern;   (5) etching the hard mask with the resist pattern;   (6) etching the underlayer film with the patterned hard mask; and   (7) processing the semiconductor substrate with the patterned underlayer film.