Sulfur atom-containing resist underlayer film forming composition and method for forming resist pattern
It is an object to provide a resist underlayer film forming composition having a selection ratio of dry etching rate larger than that of a resist film and exhibiting a low k value and a high n value at a short wavelength such as that of an ArF excimer laser, and enabling the formation of a resist pattern having a desired shape. When the composition is produced or used, it is required that odor due to a raw material monomer causes no problem. The object is solved by a resist underlayer film forming composition for lithography containing a polymer having in backbone thereof, a disulfide bond (S—S bond), and a solvent. The polymer may be a product of a reaction between at least one type of compound (diepoxy compound) containing two epoxy groups and at least one type of dicarboxylic acid containing a disulfide bond.
1. A resist underlayer film forming composition for lithography comprising:
a polymer having a disulfide bond in backbone thereof: and
a solvent:
wherein the polymer has a repeating unit structure of Formula (1):
where X is a group of Formula (2), Formula (3), or Formula (4):
where R 1 to R 5 are each independently a hydrogen atom, a C 1-6 alkyl group, a C 3-6 alkenyl group, a benzyl group, or a phenyl group, where the phenyl group is optionally substituted with at least one group selected from a group consisting of a C 1-6 alkyl group, a halogen atom, a C 1-6 alkoxy group, a nitro group, a cyan group, and a C 1-6 alkylthio group, and R 1 and R 2 or R 3 and R 4 are optionally bonded to each other to form a C 3-6 ring;
A 1 to A 6 are each independently a hydrogen atom, a methyl group, or an ethyl group;
Q 1 is a divalent group containing a disulfide bond; and
n is the number of repeating unit structures which is an integer of 5 to 100.
2. The resist underlayer film forming composition for lithography according to claim 1 , wherein Formula (1) is Formula (5):
where X is a group of Formula (2), Formula (3), or Formula (4); R 6 and R 7 are each independently a C 1-3 alkylene group or a direct bond; and p is the number of repeating unit structures which is an integer of 5 to 100.
3. The resist underlayer film forming composition for lithography according to claim 1 , further comprising:
a crosslinkable compound; and
a sulfonic acid compound.
4. The resist underlayer film forming composition for lithography according to claim 1 , further comprising a surfactant.
5. A method for forming a resist pattern used in the production of a semiconductor device comprising:
applying the resist underlayer film forming composition for lithography as claimed in claim 1 on a semiconductor substrate and baking the composition to form a resist underlayer film;
applying a resist on the resist underlayer film and baking the resist to form a resist film;
exposing the semiconductor substrate coated with the resist underlayer film and the resist film to light; and
developing the resist film after the exposure.
6. A resist underlayer film forming composition for lithography comprising:
a solvent; and
a polymer having a repeating unit structure of Formula (6):
where
X is a group of Formula (2), Formula (3), or Formula (4):
where R 1 to R 5 are each independently a hydrogen atom, a C 1-6 alkyl group, a C 3-6 alkenyl group, a benzyl group, or a phenyl group, where the phenyl group is optionally substituted with at least one group selected from a group consisting of a C 1-6 alkyl group, a halogen atom, a C 1-6 alkoxy group, a nitro group, a cyano group, and a C 1-6 alkylthio group, and R 1 and R 2 or R 3 and R 4 are optionally bonded to each other to form a C 3-6 ring:
R 6 and R 7 are each independently a C 1-3 alkylene group or a direct bond;
R 8 is a C 1-3 alkylene group;
m is 0 or 1; and
r is the number of repeating unit structures which is an integer of 5 to 100.
7. The resist underlayer film forming composition for lithography according to claim 6 , further comprising:
a crosslinkable compound; and
a sulfonic acid compound.
8. The resist underlayer film forming composition for lithography according to claim 6 , further comprising a surfactant.
9. A method for forming a resist pattern used in the production of a semiconductor device comprising:
applying the resist underlayer film forming composition for lithography as claim in claim 6 on a semiconductor substrate and baking the composition to form a resist underlayer film;
applying a resist on the resist underlayer film and baking the resist to form a resist film;
exposing the semiconductor substrate coated with the resist underlayer film and the resist film to light; and
developing the resist film after the exposure.