Resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-9846360-B2
Application number	US-201615196865-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Jun 30, 2015
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A resist composition is provided comprising (A) a fluorine-containing polymer, (B) a base resin, (C) an acid generator, and (D) a solvent mixture of a first solvent which is a C 5 -C 8 ketone, C 4 -C 6 alcohol, C 3 -C 6 ether or C 4 -C 9 ester and a second solvent which is a lactone ring-containing C 6 -C 9 compound. A pattern is formed by coating the resist composition, prebake, exposure, and development. In immersion lithography, the resist film is improved in water slip. In EB or EUV lithography, outgassing is suppressed and edge roughness is reduced.

First claim

The invention claimed is:

1. A resist composition comprising
(A) a fluorine-containing polymer,
(B) a base resin adapted to increase its solubility in alkaline developer under the action of acid,
(C) an acid generator, and
(D) an organic solvent mixture containing (D-1) a first solvent selected from the group consisting of C 5 -C 8 ketones, C 4 -C 6 alcohols having at least one group selected from alkoxy, carbonyl and ester groups, C 3 -C 6 ethers having a hydroxyl group or two ether groups, and C 4 -C 9 esters having an ether or hydroxyl group, and (D-2) a second solvent which is a monocyclic lactone ring-containing C 6 -C 9 compound, the second solvent being added in an amount of more than 200 parts to 1,000 parts by weight per 100 parts by weight of the base resin.

2. The resist composition of claim 1 wherein
the C 5 -C 8 ketones include cyclohexanone, cyclopentanone, 2-heptanone, and 2-octanone,
the C 4 -C 6 alcohols having at least one group selected from alkoxy, carbonyl and ester groups include 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol,
the C 3 -C 6 ethers having a hydroxyl group or two ether groups include propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether, and
the C 4 -C 9 esters having an ether or hydroxyl group include ethylene glycol monoacetate, propylene glycol monoacetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethyl lactate, ethyl pyruvate, butyl pyruvate, butyl acetate, pentyl acetate, isopentyl acetate, hexyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, and propylene glycol mono-t-butyl ether acetate.

3. The resist composition of claim 1 wherein the second solvent is at least one member selected from the group consisting of γ-hexalactone, δ-hexalactone, γ-heptalactone, δ-heptalactone, γ-octalactone, and δ-octalactone.

4. The resist composition of claim 1 wherein the fluorine-containing polymer contains an α-trifluoromethylhydroxy group and/or fluorinated hydrocarbon group.

5. The resist composition of claim 4 wherein the fluorine-containing polymer comprises recurring units having the formula (1) and/or recurring units having the formula (2):

wherein R 1 and R 4 are each independently hydrogen or methyl,
R 2 is a single bond, a straight, branched or cyclic C 1 -C 12 alkylene group which may contain an ether, ester or carbonyl moiety, or a phenylene group,
R 3 is hydrogen, fluorine, methyl, trifluoromethyl or difluoromethyl, or R 3 may bond with R 2 to form a ring which may contain an ether, fluorinated alkylene or trifluoromethyl moiety,
R 5 is a single bond or a straight, branched or cyclic C 1 -C 12 alkylene group which may contain an ether, ester or carbonyl moiety,
R 6 is a fluorinated, straight, branched or cyclic C 1 -C 10 alkyl or phenyl group, which may contain an ether, ester, sulfone, sulfonic acid ester or sulfonamide moiety,
m is 1 or 2,
in case of m=1, X 1 is a single bond, phenylene group, —O—, —C(═O)—O—R 7 — or —C(═O)—NH—R 7 —, R 7 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain an ester or ether moiety,
in case of m=2, X 1 is benzenetriyl, —C(═O)—O—R 8 ═ or —C(═O)—NH—R 8 ═, R 8 is an optionally ester or ether-containing, straight, branched or cyclic C 1 -C 10 alkylene group, with one hydrogen atom eliminated,
X 2 is a single bond, phenylene group, —O—, —C(═O)—O—R 7 — or —C(═O)—NH—R 7 —,
a1 and a2 are numbers satisfying 0≦a1<1.0, 0≦a2<1.0, and 0.5≦a1+a2≦1.0.

6. The resist composition of claim 1 wherein the base resin comprises recurring units having the formula (7) and/or recurring units having the formula (8):

wherein R 10 and R 12 are each independently hydrogen or methyl,
R 11 and R 14 are each independently an acid labile group,
Y 1 is a single bond, phenylene, naphthylene or —C(═O)—O—R 15 —, R 15 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain an ether moiety, ester moiety, lactone ring or hydroxyl moiety, a phenylene group or naphthylene group,
Y 2 is a single bond, phenylene, naphthylene,

—C(═O)—O—R 16 —, —C(═O)—NH—R 16 —, —O—R 16 — or —S—R 16 —, R 16 is a straight, branched or cyclic C 1 -C 10 alkylene group which may contain an ether moiety, ester moiety, lactone ring or hydroxyl moiety,
R 13 is a single bond, a straight, branched or cyclic C 1 -C 16 divalent to pentavalent aliphatic hydrocarbon group which may contain an ether or ester moiety, or a phenylene group,
d1 and d2 are numbers satisfying 0≦d1<1.0, 0≦d2<1.0, and 0<d1+d2≦1.0, and n is an integer of 1 to 4.

7. The resist composition of claim 1 wherein 0.1 to 15 parts by weight of the fluorine-containing polymer is present per 100 parts by weight of the base resin.

8. A pattern forming process comprising the steps of coating the resist composition of claim 1 onto a substrate, prebaking the composition to form a resist film, exposing the resist film, and developing the exposed resist film.

9. The process of claim 8 wherein the exposure step is to expose the resist film to KrF excimer laser of wavelength 248 nm, ArF excimer laser of wavelength 193 nm, EUV of wavelength 3 to 15 nm, or EB.

10. The process of claim 9 wherein the exposure step is to expose the resist film to ArF excimer laser by immersion lithography.

11. The resist composition of claim 1 wherein the second solvent is at least one member selected from the group consisting of γ-hexalactone, δ-hexalactone, γ-heptalactone, and δ-heptalactone.

12. The resist composition of claim 1 wherein the first solvent is added in an amount of 200 to 5,000 parts by weight per 100 parts by weight of the base resin.

13. The resist composition of claim 1 wherein the acid generator (C) has the formula (13):

wherein R 300 and R 310 are each independently a straight, branched or cyclic C 1 -C 30 monovalent hydrocarbon group which may contain a heteroatom, R 320 is a straight, branched or cyclic C 1 -C 30 divalent hydrocarbon group which may contain a heteroatom, any two or more of R 300 , R 310 and R 320 may bond together to form a ring with the sulfur atom to which they are attached, L A is a single bond, ether group, or a straight, branched or cyclic C 1 -C 20 divalent hydrocarbon group which may contain a heteroatom, X A , X B , X C and X D are each independently hydrogen, fluorine or trifluoromethyl, with the proviso that at least one of X A , X B , X C and X D is fluorine or trifluoromethyl.

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Adachi Teppei

Classifications

• H10P76/2041

  Photolithographic processes · CPC title

• G03F7/38

  Treatment before imagewise removal, e.g. prebaking {(G03F7/265 takes precedence)} · CPC title

• G03F7/2041

  in the presence of a fluid, e.g. immersion; using fluid cooling means · CPC title

• G03F7/2037

  Exposure with X-ray radiation or corpuscular radiation, through a mask with a pattern opaque to that radiation · CPC title

• G03F7/0048 Primary

  characterised by the solvents or agents facilitating spreading, e.g. tensio-active agents · CPC title