Non-ionic low diffusing photo-acid generators

Patent metadata

Field	Value
Publication number	US-9950999-B2
Application number	US-201615235342-A
Country	US
Kind code	B2
Filing date	Aug 12, 2016
Priority date	Aug 12, 2016
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Non-ionic photo-acid generating (PAG) compounds were prepared that contain an aryl ketone group. The disclosed non-polymeric PAGs release a strong 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 undergo a thermal reaction to form a sulfonic acid.

First claim

What is claimed is:

1. A compound of formula (3):

wherein
n is 1,
Ar is a monovalent aryl radical selected from the group consisting of

and
R′ is 1-adamantyl.

2. The compound of claim 1 , wherein Ar is

3. The compound of claim 1 , wherein Ar is

4. The compound of claim 3 , wherein Ar is

5. The compound of claim 4 , wherein Ar is

6. The compound of claim 3 , wherein Ar is

7. The compound of claim 3 , wherein Ar is

8. The compound of claim 7 , wherein Ar is

9. The compound of claim 1 , wherein Ar is

10. A compound of formula (3):

wherein
n is 2,
Ar is a monovalent aryl radical selected from the group consisting of

R′ is 1,6-hexylene (*—CH 2 (CH 2 ) 4 CH 2 —*).

11. The compound of claim 10 , wherein Ar is

12. The compound of claim 11 , wherein Ar is

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

14. The resist formulation of claim 13 , wherein the resist formulation is positive-tone.

15. The resist formulation of claim 13 , wherein the resist formulation is negative-tone.

16. The resist formulation of claim 13 , wherein the PAG compound is capable of forming an acid when exposed to radiation.

17. The resist formulation of claim 15 , wherein the radiation is selected from the group consisting of electron beam, deep ultraviolet light, and extreme ultraviolet light.

18. The resist formulation of claim 13 , wherein the PAG compound is capable of forming an acid when heated to a temperature of about 150° C. or higher.

19. A method, comprising:
casting a resist formulation comprising a solvent, a resin capable of chemical amplification, a base, and the PAG 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 PAG 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 PAG compound to the radiation;
heating the exposed resist layer, thereby forming a heated exposed resist layer comprising heated exposed regions of the exposed resist layer and heated non-exposed regions of the exposed resist layer, wherein the heated exposed regions have greater solubility in a given alkaline developer compared to the heated non-exposed regions; and
selectively removing the heated exposed regions using the given alkaline developer, thereby forming a patterned resist layer disposed on the surface of the substrate, the patterned resist layer comprising the heated non-exposed regions of the heated exposed resist layer.

20. The method of claim 19 , comprising transferring the patterned resist layer to the substrate.

21. The method of claim 19 , comprising heating the patterned resist layer at a temperature effective in forming an acid by a thermal reaction of the PAG compound, thereby forming a patterned resist layer that is soluble in the given alkaline developer.

22. A method, comprising:
casting a resist formulation comprising a solvent, a resin capable of chemical amplification, a base, and the PAG compound of claim 1 on a surface of a substrate and removing the solvent, thereby forming a layered structure comprising a resist layer disposed on the surface of the substrate, the resist layer comprising the resin, the base quencher, and the PAG compound;
optionally baking the resist layer;
exposing the resist layer pattern-wise to radiation, thereby forming an exposed resist layer comprising exposed regions and non-exposed regions of the exposed resist layer, the exposed regions of exposed resist layer comprising an acid formed by exposing the PAG 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 of the heated exposed resist layer, wherein the heated exposed regions have lower solubility in a given developer compared to the heated non-exposed regions; and
selectively removing the heated non-exposed regions using the given developer, thereby forming a patterned resist layer disposed on the surface of the substrate, the patterned resist layer comprising the heated exposed regions of the heated exposed resist layer.

Assignees

• IBM
• Central Glass Co Ltd

Inventors

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

Classifications

• G03F7/0392

  the macromolecular compound being present in a chemically amplified positive 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

• C07C309/69 Primary

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

• G03F7/0046

  with perfluoro compounds, e.g. for dry lithography (G03F7/0048 takes precedence) · CPC title

• G03F7/38

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