Composition for forming resist underlying film
R 1 a R 2 b Si(R 3 ) 4-(a+b) (1) A composition for a silicon-containing resist underlying film and for forming a resist underlying film that can be removed by a conventional method employing dry etching, but also by a method employing wet etching using a chemical liquid in a step for processing a semiconductor substrate or the like; and a composition for forming a resist underlying film for lithography and for forming a resist underlying film that has excellent storage stability and produces less residue in a dry etching step. A composition for forming a resist underlying film, the composition including a hydrolysis condensate of a hydrolysable silane mixture containing an alkyltrialkoxy silane and a hydrolysable silane of formula (1), wherein the contained amount of the alkyltrialkoxy silane in the mixture is 0 mol % or more but less than 40 mol % with respect to the total amount by mole of all of the hydrolysable silane contained in the mixture.
1 . A resist underlayer film-forming composition comprising a hydrolysis condensate of a hydrolyzable silane mixture containing an alkyltrialkoxysilane and a hydrolyzable silane of the following Formula (1):
R 1 a R 2 b Si(R 3 ) 4-(a+b) (1)
wherein R 1 is a group bonded to the silicon atom, and is an organic group containing at least one group containing a succinic anhydride skeleton,
R 2 is a group bonded to the silicon atom, and is each independently a substitutable alkyl group, a substitutable halogenated alkyl group, a substitutable alkoxyalkyl group, or an organic group containing an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or any combination of these;
R 3 is a group or atom bonded to the silicon atom, and is each independently an alkoxy group, an aralkyloxy group, an acyloxy group, or a halogen atom;
a is 1;
b is an integer of 0 to 2; and
4−(a+b) is an integer of 1 to 3, wherein the amount of the alkyltrialkoxysilane contained in the hydrolyzable silane mixture is 0% by mole or more and less than 40% by mole relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
2 . The resist underlayer film-forming composition according to claim 1 , wherein the hydrolyzable silane mixture further contains a hydrolyzable silane of the following Formula (2):
R 4 c Si(R 5 ) 4-c (2)
wherein R 4 is a group bonded to the silicon atom, and is each independently a substitutable alkyl group, a substitutable halogenated alkyl group, a substitutable alkoxyalkyl group, or an organic group containing an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or any combination of these;
R 5 is a group or atom bonded to the silicon atom, and is each independently an alkoxy group, an aralkyloxy group, an acyloxy group, or a halogen atom; and
c is an integer of 0 to 3.
3 . The resist underlayer film-forming composition according to claim 1 , wherein the amount of the compound of Formula (1) contained in the hydrolyzable silane mixture is 5% by mole or more relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
4 . The resist underlayer film-forming composition according to claim 1 , wherein the amount of the compound of Formula (1) wherein R 1 is an organic group containing a succinic anhydride skeleton contained in the hydrolyzable silane mixture is 1% by mole or more relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
5 . The resist underlayer film-forming composition according to claim 1 , wherein the composition has a pH of 2 to 5.
6 . A pattern formation method comprising:
a step of forming an organic underlayer film on a semiconductor substrate;
a step of applying, onto the organic underlayer film, the resist underlayer film-forming composition according to claim 1 ;
a step of baking the composition, to thereby form a silicon-containing resist underlayer film;
a step of applying a resist film-forming composition onto the silicon-containing resist underlayer film, to thereby form a resist film;
a step of exposing the resist film to light, and developing the resist film, to thereby form a resist pattern;
a step of etching the silicon-containing resist underlayer film with the resist pattern as a mask; and
a step of etching the organic underlayer film with the patterned silicon-containing resist underlayer film as a mask.
7 . The pattern formation method according to claim 6 , wherein the method further comprises a step of removing the silicon-containing resist underlayer film by a wet process using a chemical after the step of etching the organic underlayer film.
8 . The pattern formation method according to claim 7 , wherein the chemical is a basic chemical.
9 . A resist underlayer film-forming composition comprising a hydrolysis condensate of a hydrolyzable silane mixture containing an alkyltrialkoxysilane and at least two hydrolyzable silanes, comprising a first and a second hydrolyzable silane, of the following Formula (1):
R 1 a R 2 b Si(R 3 ) 4-(a+b) (1)
wherein in both the first and the second hydrolysable silane:
R 2 is a group bonded to the silicon atom, and is each independently a substitutable alkyl group, a substitutable halogenated alkyl group, a substitutable alkoxyalkyl group, or an organic group containing an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or any combination of these;
R 3 is a group or atom bonded to the silicon atom, and is each independently an alkoxy group, an aralkyloxy group, an acyloxy group, or a halogen atom;
a is 1;
b is an integer of 0 to 2; and
4−(a+b) is an integer of 1 to 3,
wherein in the first hydrolyzable silane, R 1 is a group bonded to the silicon atom, and is an organic group containing a succinic anhydride skeleton, and
wherein in the second hydrolyzable silane, R 1 is a group bonded to the silicon atom, and is a group of the following Formula (1-2):
wherein X 101 is any of groups of the following Formula (1-3) to (1-5), and the carbon atom of the ketone group in each of the following Formula (1-4) and (1-5) is bonded to the nitrogen atom bonded to R 102 in Formula (1-2):
wherein R 103 to R 107 are each independently a hydrogen atom, a substitutable alkyl group, a substitutable alkenyl group, or an organic group containing an epoxy group or a sulfonyl group;
R 101 is each independently a hydrogen atom, a substitutable alkyl group, a substitutable alkenyl group, or an organic group containing an epoxy group or a sulfonyl group;
R 102 is each independently an alkylene group, a hydroxyalkylene group, a sulfide bond (—S—), an ether bond (—O—), or an ester bond (—C(═O)—O— or —O—C(═O)—); and
wherein the amount of the alkyltrialkoxysilane contained in the hydrolyzable silane mixture is 0% by mole or more and less than 40% by mole relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
10 . The resist underlayer film-forming composition according to claim 9 , wherein the hydrolyzable silane mixture further contains a hydrolyzable silane of the following Formula (2):
R 4 c Si(R 5 ) 4-c (2)
wherein R 4 is a group bonded to the silicon atom, and is each independently a substitutable alkyl group, a substitutable halogenated alkyl group, a substitutable alkoxyalkyl group, or an organic group containing an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, an amide group, an alkoxy group, a sulfonyl group, or a cyano group, or any combination of these;
R 5 is a group or atom bonded to the silicon atom, and is each independently an alkoxy group, an aralkyloxy group, an acyloxy group, or a halogen atom; and
c is an integer of 0 to 3.
11 . The resist underlayer film-forming composition according to claim 9 , wherein a total amount of the hydrolyzable silanes of Formula (1) contained in the hydrolyzable silane mixture is 5% by mole or more relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
12 . The resist underlayer film-forming composition according to claim 9 , wherein an amount of the first hydrolyzable silane contained in the hydrolyzable silane mixture is 1% by mole or more relative to the total amount by mole of all hydrolyzable silanes contained in the hydrolyzable silane mixture.
13 . The resist underlayer film-forming composition according to claim 9 , wherein the composition has a pH of 2 to 5.
14 . A pattern formation method comprising:
a step of forming an organic underlayer film on a semiconductor substrate;
a step of applying, onto the organic underlayer film, the resist underlayer film-forming composition according to claim 9 ;
a step of baking the composition, to thereby form a silicon-containing resist underlayer film;
a step of applying a resist film-forming composition onto the silicon-containing resist underlayer film, to thereby form a resist film;
a step of exposing the resist film to light, and developing the resist film, to thereby form a resist pattern;
a step of etching the silicon-containing resist underlayer film with the resist pattern as a mask; and
a step of etching the organic underlayer film with the patterned silicon-containing resist underlayer film as a mask.
15 . The pattern formation method according to claim 14 , wherein the method further comprises a step of removing the silicon-containing resist underlayer film by a wet process using a chemical after the step of etching the organic underlayer film.
16 . The pattern formation method according to claim 15 , wherein the chemical is a basic chemical.