Resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-10613437-B2
Application number	US-201815920744-A
Country	US
Kind code	B2
Filing date	Mar 14, 2018
Priority date	Mar 17, 2017
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A resist composition comprising a base polymer and a sulfonium or iodonium salt capable of generating sulfonic acid bonded to iodized benzene ring offers a high sensitivity and minimal LWR independent of whether it is of positive or negative tone.

First claim

The invention claimed is:

1. A resist composition comprising a base polymer and a sulfonium salt having the formula (A-1) and/or an iodonium salt having the formula (A-2):

wherein R 1 is a hydroxyl group, carboxyl group, C 1 -C 6 straight, branched or cyclic alkyl or alkoxy group, C 2 -C 6 straight, branched or cyclic acyloxy group, fluorine, chlorine, bromine, amino, —NR 8 —C(═O)—R 9 , or —NR 8 —C(═O)—O—R 9 , R 8 is hydrogen or a C 1 -C 6 straight, branched or cyclic alkyl group, R 9 is a C 1 -C 6 straight, branched or cyclic alkyl group or C 2 -C 8 straight, branched or cyclic alkenyl group;
R 2 is a C 2 -C 12 straight, branched or cyclic alkylene group or C 6 -C 10 arylene group, at least one hydrogen in the alkylene group being optionally substituted by a halogen other than fluorine, at least one hydrogen in the arylene group being optionally substituted by a C 1 -C 10 straight, branched or cyclic alkyl or alkoxy moiety, halogen other than fluorine, or hydroxyl moiety,
R 3 , R 4 and R 5 are each independently fluorine, chlorine, bromine, iodine, C 1 -C 12 straight, branched or cyclic alkyl group, C 2 -C 12 straight, branched or cyclic alkenyl group, C 6 -C 20 aryl group, or C 7 -C 12 aralkyl or aryloxoalkyl group, at least one hydrogen in the foregoing groups being optionally substituted by a hydroxyl, carboxyl, halogen, oxo, cyano, amide, nitro, sultone, sulfone or sulfonium salt-containing moiety, or at least one carbon in the foregoing groups being optionally substituted by an ether, ester, carbonyl, carbonate or sulfonate moiety, or R 3 and R 4 may bond together to form a ring with the sulfur atom to which they are attached,
R 6 and R 7 are each independently trifluoromethyl, a C 6 -C 10 aryl group, C 2 -C 6 straight, branched or cyclic alkenyl group, or C 2 -C 6 straight, branched or cyclic alkynyl group, at least one hydrogen in the foregoing groups being optionally substituted by a halogen, trifluoromethyl, C 1 -C 10 straight, branched or cyclic alkyl or alkoxy, hydroxyl, carboxyl, C 2 -C 10 straight, branched or cyclic alkoxycarbonyl, nitro or cyano moiety,
X 1 is a single bond, or a (p+1)-valent C 1 -C 20 linking group which may contain an ether, carbonyl, ester, amide, sultone, lactam, carbonate, halogen, hydroxyl or carboxyl moiety,
X 2 is an ether group or —NR 10 —, R 10 is hydrogen or C 1 -C 4 straight or branched alkyl group,
m is an integer of 1 to 5, n is an integer of 0 to 3, and p is an integer of 1 to 3.

2. The resist composition of claim 1 wherein m is equal to 3.

3. The resist composition of claim 1 wherein the sulfonium salt and/or iodonium salt functions as a quencher.

4. The resist composition of claim 3 , further comprising an acid generator capable of generating a sulfonic acid, imide acid or methide acid.

5. The resist composition of claim 1 wherein the sulfonium salt and/or iodonium salt functions as an acid generator.

6. The resist composition of claim 5 , further comprising a quencher.

7. The resist composition of claim 1 , further comprising an organic solvent.

8. The resist composition of claim 1 wherein the base polymer comprises recurring units having the formula (a1) or recurring units having the formula (a2):

wherein R A is each independently hydrogen or methyl, R 11 and R 12 each are an acid labile group, Y 1 is a single bond, phenylene group, naphthylene group, or C 1 -C 12 linking group containing an ester moiety and/or lactone ring, and Y 2 is a single bond or ester group.

9. The resist composition of claim 8 , further comprising a dissolution inhibitor.

10. The resist composition of claim 8 which is a chemically amplified positive resist composition.

11. The resist composition of claim 1 wherein the base polymer is free of an acid labile group.

12. The resist composition of claim 11 , further comprising a crosslinker.

13. The resist composition of claim 11 which is a chemically amplified negative resist composition.

14. The resist composition of claim 1 , further comprising a surfactant.

15. The resist composition of claim 1 wherein the base polymer further comprises recurring units of at least one type selected from the formulae (f1) to (f3):

wherein R A is each independently hydrogen or methyl,
Z 1 is a single bond, phenylene group, —O—Z 12 — or —C(═O)—Z 11 —Z 12 —, Z 11 is —O— or —NH—, Z 12 is a C 1 -C 6 straight, branched or cyclic alkylene group, C 2 -C 6 straight, branched or cyclic alkenylene group or phenylene group, which may contain a carbonyl, ester, ether or hydroxy moiety,
R 21 to R 28 are each independently a C 1 -C 12 straight, branched or cyclic alkyl group which may contain a carbonyl, ester or ether moiety, or a C 6 -C 12 aryl group or C 7 -C 20 aralkyl group, in which at least one hydrogen may be substituted by a C 1 -C 10 straight, branched or cyclic alkyl moiety, halogen, trifluoromethyl, cyano, nitro, hydroxyl, mercapto, C 1 -C 10 straight, branched or cyclic alkoxy moiety, C 2 -C 10 straight, branched or cyclic alkoxycarbonyl moiety, or C 2 -C 10 straight, branched or cyclic acyloxy moiety, any two of R 23 , R 24 and R 25 , or any two of R 26 , R 27 and R 28 may bond together to form a ring with the sulfur atom to which they are attached,
Z 2 is a single bond, —Z 21 —C(═O)—O—, —Z 21 —O— or —Z 21 —O—C(═O)—, Z 21 is a C 1 -C 12 straight, branched or cyclic alkylene group which may contain a carbonyl, ester or ether moiety,
A is hydrogen or trifluoromethyl,
Z 3 is a single bond, methylene group, ethylene group, phenylene group, fluorinated phenylene group, —O—Z 32 —, or —C(═O)—Z 31 —Z 32 —, Z 31 is —O— or —NH—, Z 32 is a C 1 -C 6 straight, branched or cyclic alkylene group, a phenylene, fluorinated phenylene or trifluoromethyl-substituted phenylene group, or C 2 -C 6 straight, branched or cyclic alkenylene group, which may contain a carbonyl, ester, ether or hydroxyl moiety, and
M − is a non-nucleophilic counter ion.

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

17. The process of claim 16 wherein the high-energy radiation is ArF excimer laser radiation of wavelength 193 nm or KrF excimer laser radiation of wavelength 248 nm.

18. The process of claim 16 wherein the high-energy radiation is electron beam or extreme ultraviolet radiation of wavelength 3 to 15 nm.

19. The resist composition of claim 1 wherein X 1 is a single bond.

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Fujiwara Takayuki

Classifications

• G03F7/2041

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

• C07C309/30

  of six-membered aromatic rings substituted by alkyl groups · CPC title

• G03F7/2006

  using coherent light; using polarised light · CPC title

• C07C309/07

  containing oxygen atoms bound to the carbon skeleton · CPC title

• C07C309/32

  containing at least two non-condensed six-membered aromatic rings in the carbon skeleton · CPC title