Resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-9250523-B2
Application number	US-201314012441-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Sep 5, 2012
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A polymer capable of increasing alkali solubility under the action of acid, as a base resin is blended with a copolymer comprising recurring units derived from acenaphthylene, indene, benzofuran or benzothiophene and fluorine-containing recurring units, as a polymeric additive to formulate a resist composition. The photoresist film formed using the resist composition is effective for minimizing outgassing therefrom during the EUV lithography. The resist film has a hydrophilic surface and is effective for suppressing formation of blob defects after development.

First claim

The invention claimed is:

1. A resist composition comprising
a polymer capable of increasing alkali solubility under the action of acid, as a base resin and
a copolymer comprising recurring units derived from at least one monomer selected from the group consisting of indene, benzofuran, and benzothiophene, and recurring units having at least one fluorine atom, as a polymeric additive,
said copolymer having the general formula (1):

wherein R 2 is hydrogen, or C 1 -C 4 straight or branched alkyl, alkoxy, acyloxy, hydroxyl, carboxyl, alkoxycarbonyl, or —OC(═O)R, wherein R is a C 1 -C 6 straight or branched alkyl or fluoroalkyl group,
R 3 and R 6 each are hydrogen or methyl,
X 2 is a single bond, —O—, —C(═O)—O—R 8 — or —C(═O)—NH—R 8 —, wherein R 8 is a single bond or a C 1 -C 4 straight or branched alkylene group which may contain an ester or ether moiety,
n is 1 or 2,
in case of n=1, X 1 is a single bond, —O—, —C(═O)—O—R 8 — or —C(═O)—NH—R 8 —, wherein R 8 is a single bond or a C 1 -C 4 straight or branched alkylene group which may be substituted with fluorine and which may contain an ester or ether moiety,
in case of n=2, X 1 is —C(═O)—O—R 9 ═ or —C(═O)—NH—R 9 ═, wherein R 9 is a trivalent group obtained by eliminating one hydrogen from a C 1 -C 10 straight, branched or cyclic alkylene group, which may be substituted with fluorine and which may contain an ester or ether moiety,
R 4 is a C 1 -C 12 straight, branched or cyclic alkylene group, phenylene group, or a combination thereof, which may be substituted with fluorine and which may contain an ester or ether moiety,
R 5 is hydrogen, fluorine, methyl, trifluoromethyl or difluoromethyl, or R 5 may bond with R 4 to form a ring which may have an ether, fluorinated alkylene or trifluoromethyl moiety,
R 7 is a C 1 -C 20 straight, branched or cyclic alkyl group which is substituted with at least one fluorine atom and which may contain an ether, ester or sulfonamide moiety,
M is a methylene group, oxygen atom or sulfur atom,
subscripts p-2, q-1 and q-2 are numbers in the range: 0<(p-2)<1.0, 0≦(q-1)<1.0, 0≦(q-2)<1.0, 0<(q-1)+(q-2)<1.0 and 0.5≦(p-2)+(q-1)+(q-2)≦1.0.

2. The resist composition of claim 1 wherein the polymer serving as a base resin comprises recurring units having an acid labile group and recurring units having a hydroxyl group and/or lactone ring as an adhesive group.

3. A pattern forming process comprising the steps of applying the resist composition of claim 1 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

4. The process of claim 3 wherein the high-energy radiation is KrF excimer laser of wavelength 248 nm, ArF excimer laser of wavelength 193 nm, electron beam or soft x-ray of wavelength 3 to 15 nm.

5. The process of claim 3 wherein the high-energy radiation is soft x-ray of wavelength 3 to 15 nm.

6. A resist composition comprising
a polymer capable of increasing alkali solubility under the action of acid, as a base resin and
a copolymer comprising recurring units derived from at least one monomer selected from the group consisting of acenaphthylene, and recurring units having at least one fluorine atom, as a polymeric additive,
said copolymer having the general formula (1):

wherein R 1 is hydrogen, or C 1 -C 4 straight or branched alkyl, alkoxy, acyloxy, hydroxyl, carboxyl, alkoxycarbonyl, or —OC(═O)R, wherein R is a C 1 -C 6 straight or branched alkyl or fluoroalkyl group,
R 3 is hydrogen or methyl,
n is 1 or 2,
in case of n=1, X 1 is a single bond, —O—, —C(═O)—O—R 8 — or —C(═O)—NH—R 8 —, wherein R 8 is a single bond or a C 1 -C 4 straight or branched alkylene group which may be substituted with fluorine and which may contain an ester or ether moiety,
in case of n=2, X 1 is —C(═O)—O—R 9 ═ or —C(═O)—NH—R 9 ═, wherein R 9 is a trivalent group obtained by eliminating one hydrogen from a C 1 -C 10 straight, branched or cyclic alkylene group, which may be substituted with fluorine and which may contain an ester or ether moiety,
R 4 is a C 1 -C 12 straight, branched or cyclic alkylene group, phenylene group, or a combination thereof, which may be substituted with fluorine and which may contain an ester or ether moiety,
R 5 is hydrogen, fluorine, methyl, trifluoromethyl or difluoromethyl, or R 5 may bond with R 4 to form a ring which may have an ether, fluorinated alkylene or trifluoromethyl moiety,
subscripts p-1 and q-1 are numbers in the range: 0<(p-1)<1.0, 0<(q-1)<1.0, and 0.5≦(p-1)+(q-1)≦1.0.

7. A pattern forming process comprising the steps of applying the resist composition of claim 6 onto a substrate to form a coating, baking, exposing the coating to high-energy radiation, and developing the exposed coating in a developer.

8. The process of claim 7 wherein the high-energy radiation is KrF excimer laser of wavelength 248 nm, ArF excimer laser of wavelength 193 nm, electron beam or soft x-ray of wavelength 3 to 15 nm.

9. The process of claim 7 wherein the high-energy radiation is soft x-ray of wavelength 3 to 15 nm.

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Funatsu Kenji
• Katayama Kazuhiro

Classifications

• G03F7/30

  Imagewise removal using liquid means · CPC title

• G03F7/11

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

• G03F7/0045

  with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors · CPC title

• G03F7/20

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

• G03F7/202

  Masking pattern being obtained by thermal means, e.g. laser ablation · CPC title