Resist underlayer film-forming composition and method for forming resist pattern using the same
A composition for forming a resist underlayer film which make possible to form a desired high-adhesion resist pattern. A resist underlayer film-forming composition for lithography containing a polymer having the following structure Formula (1) or (2) at a terminal of a polymer chain, crosslinker, compound promoting crosslinking reaction, and organic solvent. (wherein R 1 is a C 1-6 alkyl group optionally having a substituent, phenyl group, pyridyl group, halogeno group, or hydroxy group, R 2 is a hydrogen atom, a C 1-6 alkyl group, hydroxy group, halogeno group, or ester group of —C(═O)O—X wherein X is a C 1-6 alkyl group optionally having a substituent, R 3 is a hydrogen atom, a C 1-6 alkyl group, hydroxy group, or halogeno group, R 4 is a direct bond or divalent C 1-8 organic group, R 5 is a divalent C 1-8 organic group, A is an aromatic ring or heteroaromatic ring, t is 0 or 1, and u is 1 or 2.)
1. A resist underlayer film-forming composition for lithography containing a polymer having a structure of Formula (1) or (2) below at a terminal of a polymer chain, a crosslinker, a compound promoting a crosslinking reaction, and an organic solvent
wherein the polymer is a reaction product of raw material monomers containing a compound of Formula (1a) below, a compound of Formula (2a) below, or both a compound of Formula (1b) below and a compound of Formula (3) below
(wherein R 1 is a C 1-6 alkyl group optionally having a substituent, a phenyl group, a pyridyl group, a halogeno group, or a hydroxy group, R 2 is a hydrogen atom, a C 1-6 alkyl group, a hydroxy group, a halogeno group, or an ester group of —C(═O)O—X wherein X is a C 1-6 alkyl group optionally having a substituent, R 3 is a hydrogen atom, a C 1-6 alkyl group, a hydroxy group, or a halogeno group, R 4 is a direct bond or a divalent C 1-8 organic group, R 5 is a divalent C 1-8 organic group, A is an aromatic ring or a heteroaromatic ring, t is 0 or 1, and u is 1 or 2).
2. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the polymer has a structural unit of Formula (4) below and a structural unit of Formula (5)below
(wherein Q 1 and Q 2 are each independently a divalent organic group having a C 1-13 hydrocarbon group and optionally having a substituent, a divalent organic group having an aromatic ring, or a divalent organic group having a heterocycle containing 1 to 3 nitrogen atoms).
3. The resist underlayer film-forming composition for lithography according to claim 2 , wherein the structural unit of Formula (4) is a structural unit of Formula (4a), (4b), or (4c) below
(wherein R 6 is a hydrogen atom, a C 1-6 alkyl group or allyl group, R 7 and R 8 are each independently a hydrogen atom or a C 1-6 alkyl group, Q 3 is a C 1-13 hydrocarbon group optionally having a substituent, or an aromatic ring optionally having a substituent, and two vs are each independently 0 or 1).
4. The resist underlayer film-forming composition for lithography according to claim 2 , wherein the structural unit of Formula (5) is a structural unit of Formula (5a), (5b), (5c), or (5d) below
(wherein R 9 and R 10 are each independently a hydrogen atom, a C 1-6 alkyl group, or an aromatic ring, R 11 is a C 1-6 alkyl group or allyl group, R 12 and R 13 are each independently a C 1-3 alkylene group, Q 4 is a C 1-13 hydrocarbon group optionally having a substituent, or an aromatic ring optionally having a substituent, and two ws are each independently 0 or 1).
5. The resist underlayer film-forming composition for lithography according to claim 2 , wherein the polymer is a polymer of Formula (6) or (7) below
(wherein R 1 is a C 1-6 alkyl group optionally having a substituent, a phenyl group, a pyridyl group, a halogeno group, or a hydroxy group, R 2 is a hydrogen atom, a C 1-6 alkyl group, a hydroxy group, a halogeno group, or an ester group of —C(═O)O—X wherein X is a C 1-6 alkyl group optionally having a substituent, R 3 is a hydrogen atom, a C 1-6 alkyl group, a hydroxy group, or a halogeno group, R 4 is a direct bond or a divalent C 1-8 organic group, R 5 is a divalent C 1-8 organic group, A is an aromatic ring or a heteroaromatic ring, t is 0 or 1, u is 1 or 2, and Y is a polymer chain having the structural unit of Formula (4) and the structural unit of Formula (5)).
6. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the polymer has a weight average molecular weight of 800 to 100,000.
7. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the organic solvent is one or a combination of two or more selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 1-ethoxy-2-propanol, ethyl lactate, butyl lactate, and cyclohexanone.
8. The resist underlayer film-forming composition for lithography according to claim 1 , further comprising an acid generator.
9. A method for forming a resist pattern comprising the steps of: applying the resist underlayer film-forming composition for lithography according to claim 1 to a semiconductor substrate, followed by baking to forming a resist underlayer film; forming a resist film on the resist underlayer film using a resist solution; exposing, through a photomask, the semiconductor substrate coated with the resist underlayer film and the resist film to radiation selected from the group consisting of a KrF excimer laser, an ArF excimer laser, an extreme ultraviolet light, and an electron beam; and developing the exposed substrate.