CHEMICALLY AMPLIFIED NEGATIVE RESIST COMPOSITION AND PATTERNING PROCESS

• US 20110212390A1
• Filed: 02/24/2011
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Watanabe, Satoshi, Ohsawa, Youichi, Hatakeyama, Jun, Domon, Daisuke, Masunaga, Keiichi
• Granted Patent: US 8,859,181 B2
• Time in Patent Office: Days
• US Class Current: 430/5
• CPC Class Codes: G03F 1/62 Pellicles, e.g. pellicle assemblies, e.g. having membrane on support frame; Preparation thereof
• CPC Class Codes: G03F 7/0045 with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• CPC Class Codes: G03F 7/0046 with perfluoro compounds, e.g. for dry lithography G03F7/0048 takes precedence
• CPC Class Codes: G03F 7/0382 the macromolecular compound being present in a chemically amplified negative photoresist composition
• CPC Class Codes: Y10S 430/11 Vinyl alcohol polymer or derivative
• CPC Class Codes: Y10S 430/111 Polymer of unsaturated acid or ester

Abstract

A chemically amplified negative resist composition is provided comprising (A) an alkali-soluble base polymer, (B) an acid generator, and (C) a nitrogen-containing compound, the base polymer (A) turning alkali insoluble under the catalysis of acid. A polymer having a fluorinated carboxylic acid onium salt on a side chain is included as the base polymer. Processing the negative resist composition by a lithography process may form a resist pattern with advantages including uniform low diffusion of acid, improved LER, and reduced substrate poisoning.

Claims

1. A chemically amplified negative resist composition comprising (A) a base polymer which is soluble in an aqueous alkaline developer, (B) an acid generator capable of generating an acid catalyst, and (C) a nitrogen-containing compound as a basic component, said base polymer as component (A) turning alkali insoluble under the action of the acid catalyst in the presence or absence of a crosslinker, wherein

a polymer comprising recurring units of a fluorinated carboxylic acid onium salt having the general formula (1) and having a weight average molecular weight of 1,000 to 50,000 is included as at least a portion of said base polymer,

2. The resist composition of claim 1 wherein the recurring units of a fluorinated carboxylic acid onium salt having the general formula (1) are recurring units of a fluorinated carboxylic acid onium salt having the general formula (2):

3. The resist composition of claim 1, wherein the polymer comprising recurring units of a fluorinated carboxylic acid onium salt further comprises units having the general formula (3):

4. The resist composition of claim 1, wherein the polymer comprising recurring units of a fluorinated carboxylic acid onium salt further comprises units having the general formula (4):

5. The resist composition of claim 1, further comprising a polymer free of recurring units of formula (1) as a portion of said base polymer.

6. The resist composition of claim 1, further comprising (D) a crosslinker which reacts with component (A) in the presence of the acid catalyst for turning component (A) alkali insoluble.

7. A pattern forming process comprising the steps of:

applying the negative resist composition of claim 1 onto a processable substrate to form a resist film,

exposing the film patternwise to high-energy radiation, and

developing the exposed film with an alkaline developer to form a resist pattern.

8. The process of claim 7 wherein the high-energy radiation is EUV or electron beam.

9. The process of claim 7 wherein the processable substrate comprises a chromium-containing material at the outermost surface.

10. The process of claim 7 wherein the processable substrate is a photomask blank.