Photoresist undercoat-forming material and patterning process

• US 20060204891A1
• Filed: 03/10/2006
• Published: 09/14/2006
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Hatakeyama, Jun
• Granted Patent: US 7,358,025 B2
• Time in Patent Office: Days
• US Class Current: 430/271.100
• CPC Class Codes: G03F 7/0392 the macromolecular compound being present in a chemically amplified positive photoresist composition
• CPC Class Codes: G03F 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement

Abstract

A material comprising a specific bisphenol compound with a group of many carbon atoms is useful in forming a photoresist undercoat. The undercoat-forming material, optionally combined with an intermediate layer having an antireflective effect, has an absorptivity coefficient sufficient to provide an antireflective effect at a thickness of at least 200 nm and a high etching resistance as demonstrated by slow etching rates with CF₄/CHF₃ and Cl₂/BCl₃ gases for substrate processing.

Claims

1. A photoresist undercoat-forming material comprising a bisphenol compound having the general formula (1):

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

4. The material of claim 1, further comprising a crosslinker and an acid generator.

5. A patterning process comprising the steps of:

applying the undercoat-forming material of claim 1 onto a processable substrate to form an undercoat layer,

applying a photoresist composition onto the undercoat layer to form a photoresist layer,

exposing the photoresist layer in a predetermined region to radiation,

developing the photoresist layer with a developer to form a photoresist pattern, and

processing the undercoat layer and the substrate through the patterned photoresist layer as a mask, by means of a dry etching apparatus.

6. The patterning process of claim 5, wherein said photoresist composition comprises a silicon atom-containing polymer, and the processing step includes dry etching the undercoat layer through the photoresist layer as a mask with an oxygen-based etching gas.

7. A patterning process comprising the steps of:

applying the undercoat-forming material of claim 1 onto a processable substrate to form an undercoat layer,

applying a silicon atom-containing intermediate layer over the undercoat layer,

applying a photoresist composition onto the intermediate layer to form a photoresist layer,

exposing the photoresist layer in a predetermined region to radiation,

developing the photoresist layer with a developer to form a photoresist pattern,

processing the intermediate layer through the patterned photoresist layer as a mask,

removing the patterned photoresist layer, and

processing the undercoat layer and then the substrate through the processed intermediate layer as a mask,

the processing steps using a dry etching apparatus.

8. The patterning process of claim 7, wherein said photoresist composition comprises a silicon atom-free polymer, and the step of processing the undercoat layer includes dry etching with an oxygen-based etching gas.

2. A photoresist undercoat-forming material comprising a resin comprising recurring units derived by novolac formation of a bisphenol compound, as represented by the general formula (2):