Resist composition and patterning process

Patent metadata

Field	Value
Publication number	US-10620533-B2
Application number	US-201615296662-A
Country	US
Kind code	B2
Filing date	Oct 18, 2016
Priority date	Oct 19, 2015
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A resist composition comprising a base polymer and a sulfonium or iodonium salt of sulfonic acid containing a morpholino group offers dimensional stability on PPD and a satisfactory resolution.

First claim

The invention claimed is:

1. A resist composition comprising a base polymer, a photoacid generator, and a sulfonium or iodonium salt having the formula (A):

wherein R 1 is a straight, branched or cyclic C 1 -C 24 alkylene group which may contain an alkoxy, ether, ester, sulfonic acid ester moiety, double bond, triple bond or aromatic moiety,
A + is a sulfonium cation having the formula (B) or iodonium cation having the formula (C):

wherein R 2 , R 3 and R 4 are each independently a straight,branched or cyclic C 1 -C 12 alkyl or oxoalkyl group, a straight, branched or cyclic C 2 -C 12 alkenyl or oxoalkenyl group, C 6 -C 20 aryl group, or C 7 -C 12 aralkyl or aryloxoalkyl group, in which at least one hydrogen of at least one of R 2 , R 3 and R 4 is substituted by a substituent containing an ether, ester, carbonyl, carbonate, hydroxyl, carboxyl, halogen, cyano, amide, nitro, sultone, sulfonic acid ester, sulfone, thiol moiety or sulfonium salt, or R 2 and R 3 may bond together to form a ring with the sulfur atom to which they are attached,
R 5 and R 6 are each independently a C 6 -C 20 aryl group in which at least one hydrogen may be substituted by a straight, branched or cyclic C 1 -C 10 alkyl or alkoxy moiety, and
the sulfonium or iodonium cation is selected from the group consisting of the following formulae:

2. The resist composition of claim 1 , wherein the photoacid generator is capable of generating sulfonic acid, imide acid or methide acid.

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

4. 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 11 and R 13 are each independently hydrogen or methyl, R 12 and R 14 are each independently an acid labile group, X is a single bond, ester group, phenylene group, naphthylene group or a C 1 -C 12 linking group containing lactone ring, and Y is a single bond or ester group.

5. The resist composition of claim 4 , further comprising a dissolution inhibitor.

6. The resist composition of claim 4 which is a chemically amplified positive resist composition.

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

8. The resist composition of claim 7 , further comprising a crosslinker.

9. The resist composition of claim 7 which is a chemically amplified negative resist composition.

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

wherein R 51 , R 55 and R 59 each are hydrogen or methyl,
R 52 is a single bond, phenylene, —O—R 63 —, or —C(═O)—Y 1 —R 63 —, Y 1 is —O— or —NH—, R 63 is a straight, branched or cyclic C 1 -C 6 alkylene or alkenylene group which may contain a carbonyl, ester, ether or hydroxyl moiety, or phenylene group,
R 53 , R 54 , R 56 , R 57 , R 58 , R 60 , R 61 , and R 62 are each independently a straight, branched or cyclic C 1 -C 12 alkyl group which may contain a carbonyl, ester or ether moiety, or a C 6 -C 12 aryl group, C 1 -C 20 aralkyl group or mercaptophenyl group,
A 1 is a single bond, —A 0 —C(═O)—O—, —A 0 —O— or —A 0 —O—C(═O)—, A 0 is a straight, branched or cyclic C 1 -C 12 alkylene group which may contain a carbonyl, ester or ether moiety,
A 2 is hydrogen or trifluoromethyl,
Z 1 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, —O—R 64 —, or —C(═O)—Z 2 —R 64 —, Z 2 is —O— or —NH—, R 64 is a straight, branched or cyclic C 1 -C 6 alkylene or alkenylene group which may contain a carbonyl, ester, ether or hydroxyl moiety, or phenylene, fluorinated phenylene or trifluoromethyl-substituted phenylene group,
M − is a non-nucleophilic counter ion, and f1, f2 and f3 are numbers in the range: 0≤f1≤0.5, 0≤f2≤0.5, 0≤f3≤0.5, and 0<f1+f2+f3≤0.5.

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

12. 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.

13. The process of claim 12 wherein the high-energy radiation is ArF excimer laser radiation of wavelength 193 nm or KrF excimer laser radiation of wavelength 248 nm.

14. The process of claim 12 wherein the high-energy radiation is electron beam or extreme ultraviolet radiation of wavelength 3 to 15 nm.

15. The resist composition of claim 1 wherein the anion in the sulfonium or iodonium salt having formula (A) are selected from the group consisting of the following formulae:

Assignees

• Shinetsu Chemical Co

Inventors

• Hatakeyama Jun
• Ohashi Masaki

Classifications

• C08F228/06

  by a heterocyclic ring containing sulfur · CPC title

• C08F220/301

  and one oxygen in the alcohol moiety · CPC title

• C07C303/32

  of salts of sulfonic acids · CPC title

• G03F7/0397

  the macromolecular compound having an alicyclic moiety in a side chain · CPC title

• C08F220/24

  containing perhaloalkyl radicals · CPC title