Fluorinated sulfonate esters of aryl ketones for non-ionic photo-acid generators

Patent metadata

Field	Value
Publication number	US-9983475-B2
Application number	US-201615235410-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Aug 12, 2016
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

Non-ionic photo-acid generating (PAG) compounds were prepared that contain an aryl ketone group having a perfluorinated substituent alpha to the ketone carbonyl. The non-polymeric PAGs release a sulfonic acid when exposed to high energy radiation such as deep UV or extreme UV light. The photo-generated sulfonic acid has a low diffusion rate in an exposed resist layer subjected to a post-exposure bake (PEB) at 100° C. to 150° C., resulting in formation of good line patterns after development. At higher temperatures, the PAGs can also undergo a thermal reaction to form a sulfonic acid. The perfluorinated substituent provides improved thermal stability and hydrolytic/nucleophilic stability.

First claim

What is claimed is:

1. A compound of formula (3):

wherein
n is a positive integer having a value of 1-4,
Ar is a monovalent aryl radical comprising one or more aromatic rings,
L′ is a single bond or a divalent C 1 -C 10 linking group,
R 1 is a monovalent perfluorinated C 1 -C 10 radical, wherein R 1 has a molecular formula consisting of elements carbon and fluorine, and
R 2 is a C 1 -C 50 radical having a valency of n.

2. The compound of claim 1 , wherein Ar is selected from the group consisting of

3. The compound of claim 1 , wherein n is 1.

4. The compound of claim 1 , wherein R 1 is selected from the group consisting of trifluoromethyl (*—CF 3 ), perfluoroethyl (*—CF 2 CF 3 ), perfluoro-n-propyl (*—CF 2 CF 2 CF 3 ), and perfluoro-n-butyl (*—CF 2 CF 2 CF 2 CF 3 ).

5. The compound of claim 1 , wherein L′ is selected from the group consisting of
i)

wherein nitrogen 3 is linked to R 2 ,
ii)

wherein oxygen 3 is linked to R 2 ,
iii)

wherein oxygen 3 is linked to R 2 , and
iv)

wherein nitrogen 3 is linked to R 2 , and wherein carbon 1 of each of the foregoing groups is linked to the sulfur of formula (3).

6. The compound of claim 1 , wherein R 2 comprises an adamantyl group.

7. The compound of claim 1 , wherein R 2 comprises a silsesquioxane group of formula (5):

wherein
L″ is a divalent C 1 -C 6 linking group, and
Z is a C 1 -C 6 alkyl group.

8. The compound of claim 7 , wherein the Z is isobutyl.

9. The compound of claim 1 , wherein the compound is selected from the group consisting of

10. The compound of claim 1 , wherein n is 2.

11. The compound of claim 10 , wherein R 2 is 1,3-phenylene.

12. The compound of claim 10 , wherein R 2 is hexan-1,6-diyl (*—CH 2 (CH 2 ) 4 CH 2 —*).

13. The compound of claim 10 , wherein the compound is selected from the group consisting of:

14. A resist formulation, comprising:
a solvent;
a resin capable of chemical amplification;
a base quencher; and
the compound of claim 1 ;
wherein
the resin, the base quencher, and the compound are in contact with the solvent, and
the resist formulation is suitable for use in a lithographic process.

15. The resist formulation of claim 14 , wherein the resist formulation is positive-tone.

16. The resist formulation of claim 14 , wherein the resist formulation is negative-tone.

17. The resist formulation of claim 14 , wherein the compound is capable of forming an acid when exposed to radiation.

18. The resist formulation of claim 17 , wherein the radiation is selected from the group consisting of electron beam, deep ultraviolet light, and extreme ultraviolet light.

19. The resist formulation of claim 14 , wherein the compound is capable of forming an acid when heated to a temperature of about 150° C. or higher.

20. A method, comprising:
casting a resist formulation comprising a solvent, a resin capable of chemical amplification, a base, and the compound of claim 1 on a surface of a substrate and removing the solvent, thereby forming a layered structure, the layered structure comprising a resist layer disposed on the surface of the substrate, the resist layer comprising the resin, the base quencher, and the compound;
optionally baking the resist layer;
exposing the resist layer pattern-wise to radiation, thereby forming an exposed resist layer comprising exposed regions of the resist layer and non-exposed regions of the resist layer, the exposed regions of resist layer comprising an acid formed by exposing the compound to the radiation;
heating the exposed resist layer, thereby forming a heated exposed resist layer comprising heated exposed regions and heated non-exposed regions; and
selectively removing the heated exposed regions or the heated non-exposed regions, thereby forming a patterned resist layer disposed on the surface of the substrate.

21. The method of claim 20 , comprising transferring the patterned resist layer to the substrate.

22. The method of claim 20 , comprising heating the patterned resist layer at a temperature effective in forming an acid by a thermal reaction of the compound, thereby forming a patterned resist layer that is soluble in the given alkaline developer.

23. The method of claim 20 , wherein the heated exposed regions are selectively removed using an given alkaline developer, and the patterned resist layer comprises the heated non-exposed regions.

24. The method of claim 20 , wherein the heated non-exposed regions are selectively removed using an organic developer, and the patterned resist layer comprises the heated exposed regions.

Assignees

• IBM
• Central Glass Co Ltd

Inventors

• Ishimaru Takehisa
• Narizuka Satoru
• Sanders Daniel P
• Sooriyakumaran Ratnam
• Truong Hoa D
• Wojtecki Rudy J

Classifications

• G03F7/0382

  the macromolecular compound being present in a chemically amplified negative photoresist composition · CPC title

• G03F7/2004

  characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light · CPC title

• C07C317/26

  having sulfone or sulfoxide groups and nitrogen atoms, not being part of nitro or nitroso groups, bound to the same carbon skeleton · CPC title

• C07C309/69

  of a carbon skeleton substituted by nitrogen atoms, not being part of nitro or nitroso groups · CPC title

• C07C309/70

  of a carbon skeleton substituted by carboxyl groups · CPC title