Composition for forming resist underlayer film for nanoimprint

Abstract

There is provided a composition for curing a resist underlayer film used as an underlayer of a resist for nanoimprint in nanoimprint lithography of a pattern forming process by heat-baking, light-irradiation or both of them to form the resist underlayer film. A composition for forming a resist underlayer film used for nanoimprint in a pattern forming process using nanoimprint by performing heat-baking, light-irradiation, or both of them, the composition comprising a silicon atom-containing polymerizable compound (A), a polymerization initiator (B) and a solvent (C). The polymerizable compound (A) may contain silicon atoms in a content of 5 to 45% by mass. The polymerizable compound (A) may be a polymerizable compound having at least one cation polymerizable reactive group, a polymerizable compound having at least one radical polymerizable reactive group, or a combination of them, and the polymerization initiator (B) may be a photopolymerization initiator.

1 . A composition for forming a resist underlayer film used for nanoimprint in a pattern forming process using nanoimprint by performing heat-baking, light-irradiation, or both of them, the composition comprising:
 a silicon atom-containing polymerizable compound (A);   a polymerization initiator (B); and   a solvent (C).   
     
     
         2 . The composition for forming the resist underlayer film according to  claim 1 , wherein the polymerizable compound (A) contains silicon atoms in a content of 5 to 45% by mass. 
     
     
         3 . The composition for forming the resist underlayer film according to  claim 1 , wherein the polymerizable compound (A) is a polymerizable compound having at least one cation polymerizable reactive group, a polymerizable compound having at least one radical polymerizable reactive group, or both of them and the polymerization initiator (B) is a photopolymerization initiator. 
     
     
         4 . The composition for forming the resist underlayer film according to  claim 1 , wherein the polymerizable compound (A) is a polymerizable compound having at least one cation polymerizable reactive group, a polymerizable compound having at least one radical polymerizable reactive group, or both of them and the polymerization initiator (B) is a thermopolymerization initiator. 
     
     
         5 . The composition for forming the resist underlayer film according to  claim 3 , wherein the cation polymerizable reactive group is an epoxy group, an oxetane group, or an organic group containing any one of or both of them. 
     
     
         6 . The composition for forming the resist underlayer film according to  claim 3 , wherein the radical polymerizable reactive group is a vinyl group or an organic group containing a vinyl group. 
     
     
         7 . The composition for forming the resist underlayer film according to  claim 1 , wherein the polymerizable compound (A) is a silicon atom-containing polymerizable compound (A1) containing at least one of organic silicon compound selected from a group consisting of
 an organic silicon compound of Formula (I):
   (R 1 ) a (R 3 ) b Si(R 2 ) 4−(a+b)    Formula (I)
 
   (where R 1  is an epoxy group, an oxetane group, a vinyl group, or a polymerizable organic group which contains one to three of an epoxy group, an oxetane group, and a vinyl group and is bonded to a silicon atom through a Si—C bond; R 3  is an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, or an organic group which has a mercapto group, an amino group, or a cyano group and is bonded to a silicon atom through a Si—C bond; R 2  is a halogen atom, a C 1-8  alkoxy group, or an acyloxy group; and a is an integer of 1, b is an integer of 0, 1, or 2, where a+b is an integer of 1, 2, or 3) and an organic silicon compound of Formula (II):
   [(R 4 ) c Si(R 5 ) 3−c ] 2 Y   Formula (II)
 
   (where R 4  is an epoxy group, an oxetane group, a vinyl group, or a polymerizable organic group which contains one to three of an epoxy group, an oxetane group, and a vinyl group and is bonded to a silicon atom through a Si—C bond; R 5  is a halogen atom, a C 1-8  alkoxy group, or an acyloxy group; Y is an oxygen atom, a methylene group, or a C 2-20  alkylene group; and c is an integer of 1 or 2), a hydrolysis product thereof, a hydrolysis-condensation product thereof, or a mixture thereof.   
     
     
         8 . The composition for forming the resist underlayer film according to  claim 1 , wherein the polymerizable compound (A) is a combination of a silicon atom-containing polymerizable compound (A1) containing at least one of organic silicon compound selected from a group consisting of
 the organic silicon compound of Formula (I) and the organic silicon compound of Formula (II), a hydrolysis product thereof, a hydrolysis-condensation product thereof, or a mixture thereof, and a silicon atom-containing polymerizable compound (A2) containing at least one of organic silicon compound selected from a group consisting of an organic silicon compound of General Formula (III):
   (R 11 ) a     1   (R 13 ) b     1   Si(R 12 ) 4−(a     1     +b     1     )    Formula (III)
 
   (where R 11  and R 13  are individually an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, or an organic group which has a mercapto group, an amino group, or a cyano group and is bonded to a silicon atom through a Si—C bond; R 12  is a halogen atom, a C 1-8  alkoxy group, or an acyloxy group; and a 1  and b 1  are individually an integer of 0, 1, or 2, where a 1 +b 1  is an integer of 0, 1, or 2) and an organic silicon compound of Formula (IV):
   [(R 14 ) c     1   Si(X) 3−c     1   ] 2 Y   Formula (IV)
 
   (where R 14  is a C 1-5  alkyl group; X is a halogen atom, a C 1-8  alkoxy group, or an acyloxy group; Y 1  is a methylene group or a C 2-20  alkylene group; and c 1  is an integer of 0 or 1), a hydrolysis product thereof, a hydrolysis-condensation product thereof, or a mixture thereof.   
     
     
         9 . The composition for forming the resist underlayer film according to  claim 1 , wherein the silicon atom-containing polymerizable compound (A) contains a combination of a polymerizable compound (A1) and a polymerizable compound (A2) in which an abundance ratio between silicon atoms in (A1) and silicon atoms in (A2) in a molar ratio is 100:0 to 50, and is a polymerizable organic group-containing condensation product having a weight average molecular weight of 100 to 100,000 produced by hydrolyzing the polymerizable compound (A1) and the polymerizable compound (A2) and by condensing the resultant hydrolyzed products. 
     
     
         10 . The composition for forming the resist underlayer film according to  claim 1 , wherein the silicon atom-containing polymerizable compound (A): contains the organic silicon compound of Formula (I) or a combination of the organic silicon compound of Formula (I) and the organic silicon compound of Formula (III); contains an organic silicon compound in which a value of a+b or a value of a+b and a value of a 1 +b 1  become(s) 1 in the organic silicon compound of Formula (I) or in both of the organic silicon compound of Formula (I) and the organic silicon compound of Formula (III) in a ratio of 5 to 75% by mass; and is a polymerizable organic group-containing condensation product having a weight average molecular weight of 100 to 1,000,000 produced by hydrolyzing the above organic silicon compounds and by condensing the resultant hydrolyzed products. 
     
     
         11 . The composition for forming the resist underlayer film according to  claim 7 , wherein the polymerizable compound (A) contains a thermally cation polymerizable reactive group and a photo radical polymerizable reactive group in a molar ratio of 10:90 to 90:10. 
     
     
         12 . The composition for forming the resist underlayer film according to  claim 1 , further containing a crosslinkable compound, a surface modifier, or both of them. 
     
     
         13 . A forming method of a laminated structure used in a pattern forming process using nanoimprint, the forming method comprising:
 a process of applying the composition for forming the resist underlayer film as claimed in  claim 1  on a substrate to form a resist underlayer film;   a process of performing heat-baking, light-irradiation, or both of them relative to the resist underlayer film to cure the resist underlayer film; and   a process of applying a resist composition for nanoimprint on the resist underlayer film and heat-baking the resultant coating to form a resist for nanoimprint.   
     
     
         14 . A forming method of a laminated structure used in a pattern forming process using nanoimprint, the forming method comprising:
 a process of applying the composition for forming the resist underlayer film as claimed in  claim 1  on a substrate to form a resist underlayer film;   a process of performing heat-baking, light-irradiation, or both of them relative to the resist underlayer film to cure the resist underlayer film;   a process of applying a resist composition for nanoimprint on the resist underlayer film and heat-baking the resultant coating to form a resist for nanoimprint; and   a process of imprinting by a step and repeat method.   
     
     
         15 . The forming method according to  claim 13 , wherein the substrate is a substrate which has a hole having an aspect ratio represented by height/diameter of 0.01 or more or a step having an aspect ratio represented by height/width of 0.01 or more. 
     
     
         16 . The forming method according to  claim 13 , wherein the light-irradiation is performed by a light having a wavelength of 250 nm to 650 nm.