Resist underlayer film-forming composition comprising polymer having structural unit having urea linkage

Patent metadata

Field	Value
Publication number	US-12025915-B2
Application number	US-201816483686-A
Country	US
Kind code	B2
Filing date	Feb 1, 2018
Priority date	Feb 3, 2017
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

A resist underlayer film-forming composition having a dramatically improved crosslinking ability over conventional compositions, and further, a resist underlayer film-forming composition that crosslinks with a component of a resist material, in order to improve the adhesion of a resist underlayer film to a resist pattern. A resist underlayer film-forming composition for lithography including a copolymer having a structural unit of formula (1) and a structural unit of formula (2):

(wherein each R 1 is independently a hydrogen atom or a methyl group; each R 2 is independently a C 1-3 alkylene group; R 3 is a single bond or a methylene group; A is a linear, branched, or cyclic aliphatic group having a carbon atom number of 1 to 12 and optionally having a substituent, or a C 6-16 aromatic or heterocyclic group optionally having a substituent; and Pr is a protecting group); a crosslinking agent; an organic acid catalyst; and a solvent.

First claim

The invention claimed is:

1. A resist underlayer film-forming composition for lithography comprising:
a copolymer having a structural unit of formula (1) and a structural unit of formula (2):

wherein each R is independently a hydrogen atom or a methyl group; each R 2 is independently a C 1-3 alkylene group; R 3 is a single bond or a methylene group; A is a linear, branched, or cyclic aliphatic group having a carbon atom number of 1 to 12 and optionally having a substituent, or a C 6-16 aromatic or heterocyclic group optionally having a substituent;

and Pr is a protecting group;
a crosslinking agent;
an organic acid catalyst; and
a solvent.

2. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the copolymer has, in addition to the structural unit of formula (1) and the structural unit of formula (2), a structural unit of formula (3):

wherein R 1 is as defined in formula (1) above; and R 4 is a linear, branched, or cyclic aliphatic group having a carbon atom number of 1 to 12, in which at least one hydrogen atom is substituted with a fluoro group, the aliphatic group optionally further having at least one hydroxy group as a substituent.

3. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the structural unit of formula (1) is any of structural units of formulae (1a) to (1j):

wherein R 1 , R 2 , and R 3 are as defined in formula (1) above; X 1 and X 2 are each independently a hydrogen atom, a hydroxy group, a halogeno group, or a methyl group in which at least one hydrogen atom is optionally substituted with a fluoro group; Y is a hydrogen atom, a methyl group, or an ethyl group; Z 1 and Z 2 are each independently a linear or branched alkyl group having a carbon atom number of 1 to 3, in which at least one hydrogen atom is optionally substituted with a fluoro group or a hydroxy group; and m is an integer from 0 to 2.

4. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the structural unit of formula (2) is a structural unit of formula (2a), a structural unit of formula (2b), a structural unit of formula (2c), or a structural unit of formula (2d):

wherein R and R 2 are as defined in formula (1) above; two R 5 s are each independently a hydrogen atom, a methyl group, or an ethyl group; R 6 is a methyl group or an ethyl group; b is an integer from 0 to 3; R 7 is a linear or branched alkyl group having a carbon atom number of 1 to 6, or a linear or branched alkoxyalkyl group having a carbon atom number of 1 to 6; R 8 is a linear or branched alkoxy group having a carbon atom number of 1 to 6; and R 9 is a hydrogen atom, or a linear or branched alkoxycarbonyl group having a carbon atom number of 2 to 6.

5. The resist underlayer film-forming composition for lithography according to claim 1 , wherein the copolymer has a weight average molecular weight of 1,500 to 20,000.

6. A method for forming a resist pattern comprising the steps of:
forming a resist underlayer film having a thickness of 1 to 25 nm by applying the resist underlayer film-forming composition for lithography according to claim 1 onto a substrate, and baking the composition;
forming a resist film by applying a resist solution onto the resist underlayer film, and heating the resist solution;
exposing the resist film to radiation selected from the group consisting of a KrF excimer laser, an ArF excimer laser, and extreme ultraviolet radiation through a photomask; and
after the exposure, developing the resist film with a developer.

7. A monomer of formula (a), (b-3), (b-4), (b-5), (b-6), (b-7), (b-8), (c), (d), (e), (g), (i), (j-3), or (j-4):

wherein:
each R 1 is independently a hydrogen atom or a methyl group;
each R 2 is independently a C 1 -3 alkylene group;
R 3 is a single bond or a methylene group in each of formula (a), (c), and (i), and R 3 is a methylene group in each of formula (d), (e), and (g);
X 2 is a hydrogen atom, a halogeno group, or a methyl group in which at least one hydrogen atom is optionally substituted with a fluoro group;
Y is a hydrogen atom, a methyl group, or an ethyl group;
Z 1 is a linear or branched alkyl group having a carbon atom number of 1 to 3, in which at least one hydrogen atom is optionally substituted with a fluoro group or a hydroxy group; and
m is an integer of 1 or 2.

Assignees

• Nissan Chemical Corp

Inventors

• Nishita Tokio
• Goto Yuichi
• Sakamoto Rikimaru
• Son Gun

Classifications

• H10P76/00

  Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title

• G03F7/11 Primary

  having cover layers or intermediate layers, e.g. subbing layers {(G03F7/091 - G03F7/093, B41N3/03 take precedence)} · CPC title

• G03F7/2053

  using a laser (ablative removal B41C) · CPC title

• C08F220/34

  Esters containing nitrogen {, e.g. N,N-dimethylaminoethyl (meth)acrylate} · CPC title