Method For Forming Resist Underlayer Film And Patterning Process

Patent metadata

Field	Value
Publication number	US-2025060670-A1
Application number	US-202418786730-A
Country	US
Kind code	A1
Filing date	Jul 29, 2024
Priority date	Aug 16, 2023
Publication date	Feb 20, 2025
Grant date	—

Abstract

The present invention provides a method for forming by plasma irradiation a resist underlayer film with excellent dry etching resistance and film thickness uniformity, the method including: (i) applying a composition containing (A) a polymer and (B) an organic solvent, and performing heat treatment; and (ii) forming a resist underlayer film by plasma irradiation, where the polymer (A) contains a constitutional unit of formula (1) and has a weight-average molecular weight of 2,500 to 20,000:

where Ar 1 and Ar 2 represent a benzene ring or naphthalene ring, X represents a structure of formula (1A), Y represents an organic group, “k” represents 0 or 1,

where “n 1 ” represents 0 or 1, “n 2 ” represents 1 or 2, R 2 represents a hydrogen atom, an organic group, or a structure of formula (1B), R 3 represents a hydrogen atom, an alkyl group, an aryl group, or a group of formula (1C), “n 3 ” represents 0 to 2,

where R A represents an organic group, R B represents a hydrogen atom or an organic group, and

where R 4 represents a hydrogen atom or hydrocarbon group.

First claim

1 . A method for forming a resist underlayer film on a substrate, the method comprising the steps of:
(i) forming an underlayer-film-precursor film by applying a composition for forming a resist underlayer film onto the substrate, the composition containing (A) a polymer and (B) an organic solvent, and subjecting the composition to heat treatment at a temperature of 100° C. or higher and 800° C. or lower for 10 seconds to 7,200 seconds to cure the composition; and (ii) forming a resist underlayer film by subjecting the substrate having the underlayer-film-precursor film formed to plasma irradiation, wherein the polymer (A) contains a constitutional unit represented by the following general formula (1) and has a weight-average molecular weight of 2,500 to 20,000 as measured by gel permeation chromatography in terms of polystyrene,

wherein Ar 1 and Ar 2 each independently represent a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthalene ring, X represents a structure represented by the following general formula (1A), Y represents a divalent organic group having 6 to 50 carbon atoms, and “k” represents 0 or 1,

wherein “n 1 ” represents 0 or 1, “n 2 ” represents 1 or 2, R 2 represents a hydrogen atom or an organic group having 1 to 10 carbon atoms or has a structure represented by one of the following general formulae (1B), R 3 represents a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a group represented by the following general formula (1C), “n 3 ” represents 0, 1, or 2, “*” represents an attachment point to the methylene group, and “**” represents an attachment point to the quaternary carbon atom of the fluorene,

wherein “*” represents an attachment point to the oxygen atom, R A represents a divalent organic group having 1 to 10 carbon atoms, and R B represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms,

wherein R 4 represents a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, a hydrogen atom on the benzene ring in the formula optionally being substituted with a methyl group or a methoxy group.

2 . The method for forming a resist underlayer film according to claim 1 , wherein the Y in the general formula (1) has a structure represented by any of the following formulae (Y-1),

wherein a hydrogen atom of the structures is optionally substituted with a hydroxy group or a monovalent organic group having 1 to 10 carbon atoms.

3 . The method for forming a resist underlayer film according to claim 1 , wherein the R 2 in the general formula (1A) is a hydrogen atom.

4 . The method for forming a resist underlayer film according to claim 1 , wherein the R 2 in the general formula (1A) is a hydrogen atom or has the structure represented by the general formula (1B), and in the structure constituting the R 2 , a proportion “a” of hydrogen atoms and a proportion “b” of the structure represented by the general formula (1B) satisfy relationships a+b=1 and 0.1≤b≤0.9.

5 . The method for forming a resist underlayer film according to claim 1 , wherein the Ar 1 and Ar 2 in the general formula (1) are each an unsubstituted benzene ring, and in the general formula (1A), “n 1 ” is 0, “n 2 ” is 1 or 2, and “n 3 ” is 0.

6 . The method for forming a resist underlayer film according to claim 1 , wherein the “k” in the general formula (1) is 0.

7 . The method for forming a resist underlayer film according to claim 1 , wherein the polymer (A) has a weight-average molecular weight of 7000 to 15,000 as measured by gel permeation chromatography in terms of polystyrene.

8 . The method for forming a resist underlayer film according to claim 1 , wherein the composition for forming a resist underlayer film further contains one or more of: (C) a crosslinking agent; (D) a surfactant; (E) an acid generator; and (F) a plasticizer.

9 . The method for forming a resist underlayer film according to claim 1 , wherein the organic solvent (B) is a mixture of one or more kinds of organic solvent having a boiling point of lower than 180° C. and one or more kinds of (B-1) a high-boiling-point solvent, being an organic solvent having a boiling point of 180° C. or higher.

10 . The method for forming a resist underlayer film according to claim 1 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

11 . The method for forming a resist underlayer film according to claim 2 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

12 . The method for forming a resist underlayer film according to claim 3 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

13 . The method for forming a resist underlayer film according to claim 4 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

14 . The method for forming a resist underlayer film according to claim 5 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

15 . The method for forming a resist underlayer film according to claim 6 , wherein the plasma irradiation in the step (ii) is performed under an atmosphere of N 2 , NF 3 , H 2 , fluorocarbon, a rare gas, or a mixture of any thereof.

16 . The method for forming a resist underlayer film according to claim 1 , wherein the heat treatment in the step (i) is performed under an atmosphere with an oxygen concentration of 1% or more and 21% or less.

17 . The method for forming a resist underlayer film according to claim 1 , wherein the heat treatment in the step (i) is performed under an atmosphere with an oxygen concentration of less than 1%.

18 . A patterning process for forming a pattern in a substrate to be processed, comprising the steps of:
(I-1) forming a resist underlayer film on a substrate to be processed by the method for forming a resist underlayer film according to claim 1 ; (I-2) forming a resist middle layer film on the resist underlayer film; (I-3) forming a resist upper layer film on the resist middle layer film by using a photoresist material; (I-4) subjecting the resist upper layer film to pattern exposure and then development with a developer to form a pattern in the resist upper layer film; (I-5) transferring the pattern to the resist middle layer film by dry etching while using the resist upper layer film having the formed pattern as a mask; (I-6) transferring the pattern to the resist underlayer film by dry etching while using the resist middle layer film having the transferred pattern as a mask; and (I-7) processing the

Assignees

• Shinetsu Chemical Co

Inventors

• Kobayashi Naoki
• Ishiwata Kenta
• Kori Daisuke
• Yano Toshiharu

Classifications

• G03F7/11 Primary

  having cover layers or intermediate layers, e.g. subbing layers {(G03F7/091 - G03F7/093, B41N3/03 take precedence)} · CPC title

• G03F7/09

  characterised by structural details, e.g. supports, auxiliary layers (supports for printing plates in general B41N) · CPC title

• G03F7/168

  Finishing the coated layer, e.g. drying, baking, soaking · CPC title

• G03F7/16 Primary

  Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74) · CPC title

• C08G10/02

  of aldehydes · CPC title