CHEMICALLY AMPLIFIED NEGATIVE RESIST COMPOSITION FOR EB OR EUV LITHOGRAPHY AND PATTERNING PROCESS

• US 20110200942A1
• Filed: 02/15/2011
• Published: 08/18/2011
• Est. Priority Date: 02/16/2010
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Tanaka, Akinobu, Watanabe, Satoshi, Domon, Daisuke, Masunaga, Keiichi
• Granted Patent: US 8,470,511 B2
• Time in Patent Office: Days
• US Class Current: 430/285.1
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G03F 7/0382 the macromolecular compound being present in a chemically amplified negative photoresist composition

Abstract

A chemically amplified negative resist composition is provided comprising (A) an alkali-soluble polymer, (B) an acid generator, and (C) a nitrogen-containing compound as a basic component, the polymer (A) turning alkali insoluble under the catalysis of acid. A basic polymer having a secondary or tertiary amine structure on a side chain serves as components (A) and (C). Processing the negative resist composition by EB or EUV lithography process may form a fine size resist pattern with advantages including uniform diffusion of base, improved LER, controlled deactivation of acid at the substrate interface, and a reduced degree of undercut.

Claims

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

a basic polymer PB comprising recurring units of the general formulae (1) and (2) and having a weight average molecular weight of 1,000 to 50,000 serves as both components (A) and (C),

2. The resist composition of claim 1 wherein said basic polymer PB further comprises units of the general formula (3):

3. The resist composition of claim 1 wherein said basic polymer PB further comprises units of the general formula (4) and/or (5):

4. The resist composition of claim 1, further comprising a polymer free of recurring units of formula (2) as part of component (A).

5. The resist composition of claim 1, further comprising a basic compound having a molecular weight of up to 1,000 as part of component (C), the basic compound being present in an amount of up to 1/20 mole per mole of the acid generator (B).

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

7. The resist composition of claim 1, further comprising a polymer comprising recurring units of the general formula M-1 or M-2 as component (A), wherein the resist composition is free of a crosslinker,

8. 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 EB or EUV radiation, and

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

9. The process of claim 8 wherein the processable substrate comprises a chromium-containing material at the outermost surface.

10. The process of claim 8 wherein the processable substrate is a photomask blank.