US-12619152-B2 - Method for producing actinic ray-sensitive or radiation-sensitive resin composition, pattern forming method, method for producing electronic device, and method for producing onium salt

US12619152B2US 12619152 B2US12619152 B2US 12619152B2US-12619152-B2

Abstract

A method for producing an actinic ray-sensitive or radiation-sensitive resin composition, the method including passing a solution including an acid compound having a pKa of 2.0 or more through a column packed with an ion-exchange resin, producing an onium salt by using the acid compound having been passed through the column, and mixing together the onium salt and a resin that undergoes an increase in polarity due to action of acid.

Inventors

Taro MIYOSHI
Shuhei Yamaguchi

Assignees

FUJIFILM CORPORATION

Dates

Publication Date: 20260505
Application Date: 20220809
Priority Date: 20210831

Claims (15)

1 . A method for producing an actinic ray-sensitive or radiation-sensitive resin composition, the method comprising: passing a solution including an acid compound (CA) having a pKa of 2.0 or more, through a column packed with an ion-exchange resin; producing an onium salt (C) by using the acid compound (CA) having been passed through the column; and mixing together the onium salt (C) and a resin (A) that undergoes an increase in polarity due to action of acid.
2 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the ion-exchange resin has, as an ion-exchange group, a strongly acidic cation-exchange group.
3 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 2 , wherein the strongly acidic cation-exchange group is a sulfonic group.
4 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the acid compound (CA) has a pKa of 3.0 or more.
5 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the acid compound (CA) is a carboxylic acid or a phenol.
6 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the acid compound (CA) is a compound represented by General formula (CA1) or (CA2) below, in General formula (CA1), j represents 0 or 1, Q C1 represents a substituent, m1 and m2 each independently represent 0 or 1, m3 represents an integer of 0 or more and (6+2j−m1−m2) or less, a sum of m1 and m2 is 1 or 2, and *'s each represent a direct bond connecting to the aromatic hydrocarbon described in General formula (CA1), and in General formula (CA2), Q C2 represents an alkyl group or a cycloalkyl group.
7 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein a value provided by subtracting, from the pKa of the acid compound (CA), a pKa of an ion-exchange group of the ion-exchange resin is 3.0 or more.
8 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the ion-exchange resin has a degree of crosslinking of 10% or less.
9 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the actinic ray-sensitive or radiation-sensitive resin composition includes the onium salt (C) in an amount of 10 mass % or more relative to a total solid content.
10 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the actinic ray-sensitive or radiation-sensitive resin composition further contains a compound (B) that generates acid in response to irradiation with an actinic ray or radiation, and the actinic ray-sensitive or radiation-sensitive resin composition has a mass-based content A C of the onium salt (C) and a mass-based content A B of the compound (B), and satisfies A C :A B =1:4 to 4:1.
11 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the resin (A) has at least one selected from the group consisting of a repeating unit represented by General formula (A1) below, a repeating unit represented by General formula (A2) below, and a repeating unit represented by General formula (A3) below, in General formula (A1), R a1 , R a2 , and R a3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, L a1 represents a single bond or a divalent linking group, Ar a1 represents an aromatic ring group, R a4 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, R a5 and R a6 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, R a4 and R a5 may be linked together to form a ring, and Ar a1 may be linked with R a3 or R a4 to form a ring, in General formula (A2), R a7 , R a8 , and R a9 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, L a2 represents a single bond or a divalent linking group, Ar a2 represents an aromatic ring group, R a10 , R a11 , and R a12 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, and two of R a10 , R a11 , and R a12 may be linked together to form a ring, and in General formula (A3), R a13 , R a14 , and R a15 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, L a3 represents a single bond or a divalent linking group, Ar a3 represents an aromatic ring group, R a16 , R a17 , and R a18 each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, and two of R a16 , R a17 , and R a18 may be linked together to form a ring.
12 . The method for producing an actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , wherein the resin (A) has a repeating unit having a group that generates acid in response to irradiation with an actinic ray or radiation.
13 . A pattern forming method comprising forming a resist film on a substrate by an actinic ray-sensitive or radiation-sensitive resin composition produced by the following method for producing an actinic ray-sensitive or radiation-sensitive resin composition, exposing the resist film, and developing the exposed resist film by a developer, said method for producing an actinic ray-sensitive or radiation-sensitive resin composition comprising the following steps: passing a solution including an acid compound (CA) having a pKa of 2.0 or more, through a column packed with an ion-exchange resin; producing an onium salt (C) by using the acid compound (CA) having been passed through the column; and mixing together the onium salt (C) and a resin (A) that undergoes an increase in polarity due to action of acid.
14 . A method for producing an electronic device, the method comprising the pattern forming method according to claim 13 .
15 . A method for producing an onium salt, the method comprising: passing a solution including an acid compound (CA) having a pKa of 2.0 or more, through a column packed with an ion-exchange resin; and producing an onium salt (C) by using the acid compound (CA) having been passed through the column.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is based on and claims priority under 35 U.S.C. § 119 from Japanese Patent Applications No. 2021-142005 filed on Aug. 31, 2021, No. 2021-201240 filed on Dec. 10, 2021, and No. 2022-100729 filed on Jun. 22, 2022, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method, a method for producing an electronic device, and a method for producing an onium salt. More specifically, the present invention relates to a method for producing an actinic ray-sensitive or radiation-sensitive resin composition suitably used for ultra-micro lithography processes applicable to fabrication processes of ultra-LSI (Large Scale Integration) and high-capacity microchips, nanoimprint mold formation processes, high-density data recording medium production processes, and the like and other photofabrication processes, a pattern forming method, a method for producing an electronic device, and a method for producing an onium salt. 2. Description of the Related Art In the related art, in the fabrication processes for semiconductor devices such as ICs (Integrated Circuits) and LSIs, lithographic microprocessing using photoresist compositions has been performed. In recent years, with an increase in the degree of integration of integrated circuits, formation of ultrafine patterns in the submicron range or the quarter micron range has come to be in demand. With this, there is also a trend for exposure wavelengths toward shorter wavelengths from the g-line to the i-line further to KrF excimer laser light; currently, exposure apparatuses using, as light sources, ArF excimer laser having the wavelength of 193 nm have been developed. In addition, as a technique of further increasing the resolving power, a technique in which the space between a projection lens and a sample is filled with a liquid having a high refractive index (hereafter, also referred to as “immersion liquid”), what is called, the immersion method has been developed. In addition, currently, lithography using, instead of excimer laser light, an electron beam (EB), X-rays, extreme ultraviolet rays (EUV), or the like has also been developed. With this, chemical amplification resist compositions that are effectively sensitive to various radiations and have high sensitivity and high resolution have been developed. For actinic ray-sensitive or radiation-sensitive resin compositions such as resist compositions, onium salts are often used. For example, WO99/54788A describes a resist composition including a resin having an aprotic onium salt. WO99/54788A describes a method for producing an aprotic onium salt compound having a hydroxyl anion by passing an aqueous solution of an aprotic onium salt compound having an acetate anion, through an anion-exchange resin, to exchange the acetate anion with a hydroxyl anion. SUMMARY OF THE INVENTION The inventors of the present invention performed studies and have found the following: in the case of using, for a resist composition, of onium salts, in particular, an onium salt including an anion whose a conjugate acid has a pKa of 2.0 or more, a resist pattern formed on a member to be processed such as a silicon wafer and etched tends to have large line width roughness (Line Width Roughness: LWR). Thus, a resist composition that includes an onium salt including an anion whose conjugate acid has a pKa of 2.0 or more and that has high post-etching LWR performance is in demand. The LWR performance means the performance of providing a pattern having a smaller LWR. An object of the present invention is to provide a method for producing an actinic ray-sensitive or radiation-sensitive resin composition that includes an onium salt including an anion whose conjugate acid has a pKa of 2.0 or more and that has high post-etching LWR performance. Another object of the present invention is to provide a pattern forming method and a method for producing an electronic device that use the method for producing an actinic ray-sensitive or radiation-sensitive resin composition, and a method for producing the onium salt. The inventors of the present invention studied the above-described objects and have found the following: for the purpose of purifying an onium salt including an anion whose conjugate acid has a pKa of 2.0 or more, subjecting the onium salt to passing through an ion-exchange resin or washing using acid causes, in addition to purification, protonation, which leads to degradation of the post-etching LWR performance. They also have found the following: a solution including an acid compound having a pKa of 2.0 or more is passed through a column packed with an ion-exchange resin and the acid compound having been passed through the column is used to produce an onium salt, to thereby suppress protona