Method for producing resin having phenolic hydroxyl group

Abstract

To provide a method for producing a resin having a phenolic hydroxyl group having good productivity.SOLUTION: A method for producing a resin including a repeating unit (a0) having a phenolic hydroxyl group includes (I) a step of polymerizing a monomer group including a monomer (i) having such a partial structure in which a phenolic hydroxyl group is protected with a structure represented by a specific general formula (1), and obtaining a high molecular weight body, and (II) a step of subjecting a protective part protected with the structure represented by the above general formula (1) in the obtained polymer to solvolysis, and thereby obtaining a phenolic hydroxyl group, in this order.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a resin having a phenolic hydroxyl group. [Background technology]

[0002] Traditionally, microfabrication has been performed by lithography using photoresist compositions in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs. In recent years, the increasing integration density of integrated circuits has led to a demand for ultrafine pattern formation in the submicron or quarter-micron range. Accordingly, there has been a trend toward shorter exposure wavelengths, from g-line to i-line and then to KrF excimer laser light, and currently, exposure machines using ArF excimer lasers with a wavelength of 193 nm as a light source have been developed. Furthermore, as a technology for further improving resolution, the so-called immersion method, in which a high-refractive-index liquid (hereinafter also referred to as "immersion liquid") is filled between the projection lens and the sample, has been developed.

[0003] Currently, in addition to excimer laser light, lithography using electron beams (EB), X-rays, extreme ultraviolet rays (EUV), etc. is also being developed. Accordingly, chemically amplified resist compositions and resins used therein that are effectively sensitive to various types of radiation and have excellent sensitivity and resolution have been developed.

[0004] Resins containing phenolic hydroxyl groups have been known as resins used in resist compositions, and methods for producing such resins have also been investigated.

[0005] For example, Patent Document 1 describes a method for producing a resin, in which a group of monomers containing p-acetoxystyrene is polymerized, and then the acetyl-protected portion of the p-acetoxystyrene is solvolyzed under basic conditions to obtain a hydroxystyrene unit. Furthermore, Patent Document 2 describes a method for producing a resin, in which a group of monomers containing p-(1-ethoxyethoxy)styrene is polymerized, and then the acetal protective moiety of p-(1-ethoxyethoxy)styrene is solvolyzed under acidic conditions to obtain a hydroxystyrene unit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-219162 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-104347 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the production method described in Patent Document 1 requires a long time for the solvolysis reaction and is therefore not industrially advantageous. In addition, the production method described in Patent Document 2 involves carrying out the solvolysis reaction under acidic conditions, which limits the types of other raw material monomers used in the production of the resin to those highly stable to acid, and raises concerns about corrosion of the reaction apparatus during production.

[0008] Therefore, an object of the present invention is to provide a method for producing a resin having a phenolic hydroxyl group with good productivity, specifically, a method for producing a resin having a phenolic hydroxyl group that has a short reaction time, has few restrictions on the resin raw materials, and can suppress corrosion of the reaction apparatus. [Means for solving the problem]

[0009] The present inventors have found that the above problems can be solved by the following configuration.

[0010] [1] A method for producing a resin containing a repeating unit (a0) having a phenolic hydroxyl group, comprising the steps of: (I) a step of polymerizing a group of monomers including a monomer (i) having a partial structure in which a phenolic hydroxyl group is protected with a structure represented by the following general formula (1) to obtain a polymer; (II) A step of obtaining the phenolic hydroxyl group of the repeating unit (a0) by solvolyzing the protecting moiety protected with the structure represented by the general formula (1) in the obtained polymer. A method for producing a resin, comprising the steps of:

[0011] [ka]

[0012] In general formula (1), X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1≦(n + m)≦(5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. * represents the bonding position of the phenolic hydroxyl group to the oxygen atom.

[0013] [2] The method for producing a resin according to [1], wherein the monomer (i) is a monomer represented by the following general formula (2) or (3):

[0014] [ka]

[0015] In general formula (2), Y1 represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, or a halogenated alkyl group. X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. R2 represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1 ≦ (n + m) ≦ (5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. l represents an integer of 0 to 2. o2 represents an integer of 0 to (4 + 2l). p2 represents an integer of 1 to (5 + 2l), provided that the relationship 1 ≦ (o2 + p2) ≦ (5 + 2l) is satisfied. When o2 represents an integer of 2 or greater, multiple R2s may be the same or different. When p2 represents an integer of 2 or more, multiple Xs, R1s, k, m, and n may be the same or different.

[0016] [ka]

[0017] In general formula (3), X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. R3 represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1 ≦ (n + m) ≦ (5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. o3 represents an integer of 0 to 5. p3 represents an integer of 1 to 6, provided that the relationship 1 ≦ (o3 + p3) ≦ 6 is satisfied. When o3 represents an integer of 2 or greater, multiple R3s may be the same or different. When p3 represents an integer of 2 or greater, multiple Xs, R1s, k, m, and n may be the same or different.

[0018] [3] The method for producing a resin according to [1] or [2], wherein X in the general formula (1), (2), or (3) represents a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C(=O)OR group (R represents a hydrocarbon group). [4] The method for producing a resin according to any one of [1] to [3], wherein the solvolysis in the step (II) is carried out in the presence of a basic compound. [5] The method for producing a resin according to [4], wherein an amine compound is used as the basic compound.

[0019] [6] (III) A method for producing the resin according to any one of [1] to [5], which comprises a step of contacting the polymer obtained after the step (II) with an acidic aqueous solution. [7] (IV) A method for producing the resin according to any one of [1] to [6], comprising a step of mixing the solution containing the polymer after completion of the step (II) with a poor solvent for the polymer. [Effects of the Invention]

[0020] According to the present invention, a method for producing a resin having a phenolic hydroxyl group with good productivity can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, when a group (atomic group) is represented without specifying whether it is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" encompasses not only unsubstituted alkyl groups (unsubstituted alkyl groups) but also substituted alkyl groups (substituted alkyl groups). Furthermore, in the present specification, the term "organic group" refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent.

[0022] In this specification, "actinic rays" or "radiation" refers to, for example, the bright line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV), X-rays, and electron beams (EB). In this specification, "light" means actinic rays or radiation. In this specification, unless otherwise specified, "exposure" includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, and X-rays, but also drawing using particle beams such as electron beams and ion beams. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0023] In this specification, the bonding direction of the divalent linking group is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "XYZ", Y may be -CO-O- or -O-CO-. The compound may be "X-CO-OZ" or "XO-CO-Z".

[0024] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic. In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (hereinafter also referred to as "molecular weight distribution") (Mw / Mn) are defined as polystyrene-equivalent values ​​measured using a Gel Permeation Chromatography (GPC) apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40°C, flow rate: 1.0 mL / min, detector: refractive index detector).

[0025] [Method for producing resin (A1)] The present invention provides a method for producing a resin containing a repeating unit (a0) having a phenolic hydroxyl group (hereinafter also referred to as "resin (A1)"), comprising the steps of: (I) a step of polymerizing a group of monomers including a monomer (i) having a partial structure in which a phenolic hydroxyl group is protected with a structure represented by the above general formula (1) to obtain a polymer; (II) A step of obtaining the phenolic hydroxyl group of the repeating unit (a0) by solvolyzing the protecting moiety protected with the structure represented by the general formula (1) in the obtained polymer. Contains, in this order: In the production method of the present invention, a monomer (i) having a specific partial structure protected by a structure represented by the above general formula (1) is used as a raw material monomer to polymerize the polymer. The above protected structure in the polymer can be deprotected in a short time under mild conditions, which is preferable from the viewpoint of industrial productivity. Furthermore, since no acidic compound is required for the deprotection reaction, there is no need to limit the types of other raw material monomers used in copolymerization to those highly stable to acid, which increases the flexibility of the resin composition. Furthermore, there is no problem of corrosion of the reaction equipment during production.

[0026] [Process (I)] The production method of the present invention includes, as step (I), a step of polymerizing a group of monomers including a monomer (i) having a partial structure in which a phenolic hydroxyl group is protected with a structure represented by the following general formula (1) to obtain a polymer. In the following, first, the polymer obtained in the above step (I) (hereinafter also referred to as "resin (A)") will be explained, and then step (I) will be explained.

[0027] <<Resin (A)>> <Repeating unit (a1) derived from monomer (i)> Resin (A) contains a repeating unit (a1) derived from a monomer (i) having a partial structure in which a phenolic hydroxyl group is protected with a structure represented by the following general formula (1): Repeating unit (a1) is a repeating unit that becomes repeating unit (a0) having a phenolic hydroxyl group in resin (A1) through step (II) described below. [ka]

[0028] In general formula (1), X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1≦(n + m)≦(5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. * represents the bonding position of the phenolic hydroxyl group to the oxygen atom.

[0029] In the general formula (1), X represents a halogen atom or an electron-withdrawing group. The halogen atom represented by X includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0030] Examples of the electron-withdrawing group represented by X include a halogenated alkyl group, a nitro group, a cyano group, and a -C(=O)OR group (wherein R represents a hydrocarbon group). Examples of halogenated alkyl groups include alkyl groups having 1 to 12 carbon atoms substituted with a halogen atom, and are preferably a trifluoromethyl group, a pentafluoroethyl group, or a nonafluorobutyl group, more preferably a trifluoromethyl group. Examples of the hydrocarbon group represented by R in the -C(=O)OR group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, and an aryl group. An alkyl group having 1 to 15 carbon atoms is preferred, and a methyl group is more preferred.

[0031] X is preferably a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C(=O)OR group, more preferably a fluorine atom, a bromine atom, an iodine atom, a trifluoromethyl group, a nitro group, or a -C(=O)OCH group, and even more preferably a fluorine atom or an iodine atom.

[0032] In the general formula (1), R1 represents a hydroxy group or an organic group. Examples of the organic group represented by R1 include an alkyl group (linear or branched), an alkoxy group (linear or branched), an alkenyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), and an aryl group (monocyclic or polycyclic).

[0033] Examples of the alkyl group include alkyl groups having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, and a t-butyl group, with a methyl group being preferred. Examples of the alkoxy group include alkoxy groups having 1 to 15 carbon atoms, such as a methoxy group, an ethoxy group, an n-propyloxy group, and a t-butyloxy group, with a methoxy group being more preferred. Examples of the alkenyl group include alkenyl groups having 2 to 15 carbon atoms, such as a vinyl group. Examples of the cycloalkyl group include cycloalkyl groups having 3 to 20 carbon atoms, such as a cyclopentyl group and a cyclohexyl group. The aryl group is preferably an aryl group having 6 to 15 carbon atoms such as a phenyl group or a naphthyl group, and more preferably a phenyl group. The organic group represented by R1 may further have a substituent, which may include a halogenated alkyl group such as a trifluoromethyl group, a -C(=O)OR group (where R represents a hydrocarbon group), a cyano group, a hydroxy group, a carboxy group, a -C-OR group (where R represents a hydrocarbon group), and the like.

[0034] R1 is preferably a hydroxyl group, an alkyl group, an alkoxy group, or an aryl group, and more preferably a hydroxyl group, a methyl group, a methoxy group, a phenyl group, or a trifluoromethylphenyl group.

[0035] In general formula (1), k represents an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

[0036] In the general formula (1), n ​​represents an integer of 0 to (4+2k), and m represents an integer of 1 to (5+2k), provided that the relationship 1≦(n+m)≦(5+2k) is satisfied. n is preferably an integer of 0 to 2, and 0 is more preferable. m is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0037] (Monomer represented by general formula (2) or (3)) The above monomer (i) is preferably a monomer represented by the following general formula (2) or (3).

[0038] [ka]

[0039] In general formula (2), Y1 represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, or a halogenated alkyl group. X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. R2 represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1 ≦ (n + m) ≦ (5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. l represents an integer of 0 to 2. o2 represents an integer of 0 to (4 + 2l). p2 represents an integer of 1 to (5 + 2l), provided that the relationship 1 ≦ (o2 + p2) ≦ (5 + 2l) is satisfied. When o2 represents an integer of 2 or greater, multiple R2s may be the same or different. When p2 represents an integer of 2 or more, multiple Xs, R1s, k, m, and n may be the same or different.

[0040] In the general formula (2), X, R1, k, n, and m have the same meanings as X, R1, k, n, and m in the general formula (1), and preferred examples are also the same.

[0041] In the general formula (2), Y1 represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, or a halogenated alkyl group. The halogen atom represented by Y1 includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group represented by Y1 includes a linear or branched alkyl group having 1 to 12 carbon atoms, preferably a methyl group or an ethyl group, and more preferably a methyl group. Examples of the halogenated alkyl group represented by Y1 include groups in which the above alkyl groups, such as trifluoromethyl, have been substituted with a halogen atom.

[0042] Y1 is preferably a hydrogen atom, a fluorine-substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a fluorine atom, more preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a fluorine atom, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0043] In the general formula (2), R2 represents a hydroxy group, a halogen atom, or an organic group. The halogen atom represented by R2 includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the organic group represented by R2 include the organic groups represented by R1 described above.

[0044] In the general formula (2), l represents an integer of 0 to 2, with 0 or 1 being preferred.

[0045] In the general formula (2), o2 represents an integer of 0 to (4+2l), and p2 represents an integer of 1 to (5+2l), provided that the relationship 1≦(o2+p2)≦(5+2l) is satisfied. o2 is preferably 0 or 1, and more preferably 0. p2 is preferably 1 or 2.

[0046] The monomer represented by the above general formula (2) is preferably a monomer represented by the following general formula (2-1) or (2-2).

[0047] [ka]

[0048] In general formula (2-1), Y1, X, R1, R2, l, o2, and p2 have the same meanings as Y1, X, R1, R2, l, o2, and p2 in general formula (2), and preferred examples are also the same.

[0049] In the general formula (2-1), n2 represents an integer of 0 to 4, and m2 represents an integer of 1 to 5, provided that the relationship 1≦(n2+m2)≦5 is satisfied. n2 is preferably an integer of 0 to 2, and 0 is more preferable. m2 is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0050] [ka]

[0051] In general formula (2-2), Y1, X, R1, R2, n2, m2, l, o2, and p2 have the same meanings as Y1, X, R1, R2, n2, m2, l, o2, and p2 in general formula (2-1), and preferred examples are also the same.

[0052] The monomer represented by the above general formula (2-1) or (2-2) is more preferably a monomer represented by the following general formula (2-1A) or (2-2A).

[0053] [ka]

[0054] In the general formula (2-1A), Y1, X, m2, l, and p2 have the same meanings as Y1, X, m2, l, and p2 in the general formula (2-1), and preferred examples are also the same.

[0055] [ka]

[0056] In the general formula (2-2A), Y1, X, m2, l, and p2 have the same meanings as Y1, X, m2, l, and p2 in the general formula (2-2), and preferred examples are also the same.

[0057] [ka]

[0058] In general formula (3), X represents a halogen atom or an electron-withdrawing group. R1 represents a hydroxy group or an organic group. R3 represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4 + 2k). m represents an integer of 1 to (5 + 2k), provided that the relationship 1 ≦ (n + m) ≦ (5 + 2k) is satisfied. When n represents an integer of 2 or greater, multiple R1s may be the same or different. When m represents an integer of 2 or greater, multiple Xs may be the same or different. o3 represents an integer of 0 to 5. p3 represents an integer of 1 to 6, provided that the relationship 1 ≦ (o3 + p3) ≦ 6 is satisfied. When o3 represents an integer of 2 or greater, multiple R3s may be the same or different. When p3 represents an integer of 2 or greater, multiple Xs, R1s, k, m, and n may be the same or different.

[0059] In the general formula (3), X, R1, k, n, and m have the same meanings as X, R1, k, n, and m in the general formula (1), and preferred examples are also the same.

[0060] In the general formula (3), R3 represents a hydroxy group, a halogen atom, or an organic group. The halogen atom represented by R3 includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the organic group represented by R3 include the organic groups represented by R1 described above.

[0061] In the general formula (3), o3 represents an integer of 0 to 5. p3 represents an integer of 1 to 6, provided that the relationship 1≦(o3+p3)≦6 is satisfied. o3 is preferably 0 or 1, and more preferably 0. p3 is preferably 1 or 2, and 1 is more preferred.

[0062] The monomer represented by the above general formula (3) is preferably a monomer represented by the following general formula (3-1).

[0063] [ka]

[0064] In the general formula (3-1), X, R1, R3, o3, and p3 have the same meanings as X, R1, R3, o3, and p3 in the general formula (3), and preferred examples are also the same.

[0065] In the general formula (3-1), n3 represents an integer of 0 to 4. m3 represents an integer of 1 to 5, provided that the relationship 1≦(n3+m3)≦5 is satisfied. n3 is preferably an integer of 0 to 2, and more preferably 0. m3 is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0066] The monomer represented by the above general formula (3-1) is more preferably a monomer represented by the following general formula (3-1A).

[0067] [ka]

[0068] In the general formula (3-1A), X, m3, and p3 have the same meanings as X, m3, and p3 in the general formula (3-1), and preferred examples are also the same.

[0069] Specific examples of the monomer (i) include, but are not limited to, the following: In the following specific examples, Me represents a methyl group.

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] The content of the repeating unit (a1) is preferably 2 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all repeating units in the resin (A), and the upper limit is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less, based on all repeating units in the resin (A).

[0074] <Repeating unit (a2)> The resin (A) preferably contains a group that decomposes under the action of an acid to increase its polarity (hereinafter also referred to as an "acid-decomposable group"), and contains a repeating unit (a2) having an acid-decomposable group. That is, it is preferable to use a monomer (ii) having an acid-decomposable group as the monomer group used in step (I). The repeating unit (a2) and the repeating unit (a3) ​​described below are repeating units that are contained as they are in the finally obtained resin (A1) as repeating units (a2) and (a3).

[0075] As described below, the finally obtained resin (A1) can be suitably used in a resist composition. When the resin (A), i.e., the resin (A1), has an acid-decomposable group, in a pattern formation method using a resist composition containing the resin (A1), typically, a positive pattern is suitably formed when an alkaline developer is used as the developer, and a negative pattern is suitably formed when an organic developer is used as the developer. As the repeating unit having an acid-decomposable group, a repeating unit having an acid-decomposable group containing an unsaturated bond is preferred in addition to the repeating units having an acid-decomposable group described below.

[0076] (Repeating unit having an acid-decomposable group) The acid-decomposable group refers to a group that decomposes under the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which a polar group is protected by a group (leaving group) that is released under the action of an acid. In other words, the resin (A) preferably has a repeating unit having a group that decomposes under the action of an acid to generate a polar group. The polarity of a resin having this repeating unit increases under the action of an acid, increasing its solubility in alkaline developers and decreasing its solubility in organic solvents. The polar group is preferably an alkali-soluble group, and examples thereof include acidic groups such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphate group, a sulfonamide group, a sulfonylimide group, an (alkylsulfonyl)(alkylcarbonyl)methylene group, an (alkylsulfonyl)(alkylcarbonyl)imide group, a bis(alkylcarbonyl)methylene group, a bis(alkylcarbonyl)imide group, a bis(alkylsulfonyl)methylene group, a bis(alkylsulfonyl)imide group, a tris(alkylcarbonyl)methylene group, and a tris(alkylsulfonyl)methylene group, as well as alcoholic hydroxyl groups. Of these, the polar group is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

[0077] Examples of the group that is eliminated by the action of an acid include groups represented by formulae (Y1) to (Y4). Formula (Y1):-C(Rx1)(Rx2)(Rx3) Formula (Y2):-C(=O)OC(Rx1)(Rx2)(Rx3) Formula (Y3):-C(R 36 )(R 37 )(OR 38 ) Formula (Y4):-C(Rn)(H)(Ar)

[0078] In formula (Y1) and formula (Y2), Rx1 to Rx3 each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), or an aryl group (monocyclic or polycyclic). When all of Rx1 to Rx3 are alkyl groups (linear or branched), it is preferable that at least two of Rx1 to Rx3 are methyl groups. In particular, it is preferable that Rx1 to Rx3 each independently represent a linear or branched alkyl group, and it is more preferable that Rx1 to Rx3 each independently represent a linear alkyl group. Two of Rx1 to Rx3 may be bonded to form a monocycle or polycycle. The alkyl groups of Rx1 to Rx3 are preferably alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The cycloalkyl groups of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The aryl group of Rx1 to Rx3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. The alkenyl group of Rx1 to Rx3 is preferably a vinyl group. The ring formed by combining two of Rx1 to Rx3 is preferably a cycloalkyl group. The cycloalkyl group formed by combining two of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. In the cycloalkyl group formed by bonding two of Rx1 to Rx3, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. In the group represented by formula (Y1) or formula (Y2), for example, Rx1 is preferably a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group. When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the alkyl group, cycloalkyl group, alkenyl group, or aryl group represented by Rx1 to Rx3, and the ring formed by bonding two of Rx1 to Rx3, further have a fluorine atom or an iodine atom as a substituent.

[0079] In formula (Y3), R 36 ~R 38 R each independently represents a hydrogen atom or a monovalent organic group. 37 and R 38 may be bonded to each other to form a ring. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. R 36 is also preferably a hydrogen atom. The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a group containing a heteroatom such as an oxygen atom and / or a heteroatom such as a carbonyl group. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more methylene groups may be replaced with a group containing a heteroatom such as an oxygen atom and / or a heteroatom such as a carbonyl group. R 38 may bond with another substituent on the main chain of the repeating unit to form a ring. 38 The group formed by bonding together the repeating unit and another substituent carried by the main chain of the repeating unit is preferably an alkylene group such as a methylene group. When the resist composition is, for example, a resist composition for EUV exposure, R 36 ~R 38 and a monovalent organic group represented by R 37 and R 38 It is also preferable that the ring formed by bonding these groups together further has a fluorine atom or an iodine atom as a substituent.

[0080] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0081] [ka]

[0082] Here, L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining these (for example, a group formed by combining an alkyl group and an aryl group). M represents a single bond or a divalent linking group. Q represents an alkyl group which may contain a heteroatom, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group combining these (for example, a group combining an alkyl group and a cycloalkyl group). The alkyl and cycloalkyl groups may, for example, have one methylene group replaced with a heteroatom such as an oxygen atom or a group containing a heteroatom such as a carbonyl group. Preferably, one of L1 and L2 is a hydrogen atom, and the other is an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining an alkylene group and an aryl group. At least two of Q, M, and L1 may be bonded to form a ring (preferably a 5- or 6-membered ring). From the viewpoint of pattern miniaturization, L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Examples of secondary alkyl groups include an isopropyl group, a cyclohexyl group, and a norbornyl group, and examples of tertiary alkyl groups include a tert-butyl group and an adamantane group. In these embodiments, Tg (glass transition temperature) and activation energy are increased, thereby ensuring film strength and suppressing fogging.

[0083] When the resist composition is, for example, a resist composition for EUV exposure, the alkyl groups, cycloalkyl groups, aryl groups, and groups combining these groups represented by L1 and L2 preferably further contain a fluorine atom or an iodine atom as a substituent. The alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups preferably contain a heteroatom such as an oxygen atom in addition to the fluorine atom or iodine atom. Specifically, the alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups may each have, for example, one methylene group replaced with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group. When the resist composition is, for example, a resist composition for EUV exposure, in the alkyl group which may contain a heteroatom, the cycloalkyl group which may contain a heteroatom, the aryl group which may contain a heteroatom, the amino group, the ammonium group, the mercapto group, the cyano group, the aldehyde group, and groups combining these, represented by Q, it is also preferable that the heteroatom is selected from the group consisting of a fluorine atom, an iodine atom, and an oxygen atom.

[0084] In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is preferably an aryl group. When the resist composition is, for example, a resist composition for EUV exposure, it is also preferable that the aromatic ring group represented by Ar and the alkyl group, cycloalkyl group, and aryl group represented by Rn have a fluorine atom or an iodine atom as a substituent.

[0085] In terms of excellent acid decomposition properties of the repeating unit, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in a leaving group protecting a polar group, it is also preferable that a ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0086] Other groups that are eliminated by the action of an acid include a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, and a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0087] The repeating unit (a2) having an acid-decomposable group is preferably a repeating unit derived from a monomer represented by any one of the following general formulas (4) to (6): That is, the monomer (ii) having an acid-decomposable group is preferably a monomer represented by any one of the following general formulas (4) to (6):

[0088] [ka]

[0089] In the general formula (4), Y4 represents a hydrogen atom, a fluorine atom, or an alkyl group. 41 , R 42 , and R 43 R each independently represents an organic group. 41 , R 42 , and R 43 Two of these may be bonded to each other to form a ring.

[0090] In the general formula (4), Y4 represents a hydrogen atom, a fluorine atom, or an alkyl group. The alkyl group represented by Y4 may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The alkyl group represented by Y4 may have a substituent, and examples of the substituent include a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Y4 is preferably a hydrogen atom or a methyl group.

[0091] In general formula (4), R 41 , R 42 , and R 43 R each independently represents an organic group. 41 , R 42 , and R 43 Examples of the organic group represented by include an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an aryl group (monocyclic or polycyclic), and a heteroaryl group (monocyclic or polycyclic).

[0092] R 41 , R 42 , and R 43 The alkyl group represented by is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. R 41 , R 42 , and R 43 The cycloalkyl group represented by is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. R 41 , R 42 , and R 43 The aryl group represented by is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group and a naphthyl group. R 41 , R 42 , and R 43The heteroaryl group represented by is preferably a heteroaryl group having 5 to 10 carbon atoms, and examples thereof include groups in which one hydrogen atom has been removed from a heterocycle such as thiophene, furan, or thiazole. R 41 , R 42 , and R 43 The alkenyl group represented by is preferably a vinyl group. R 41 , R 42 , and R 43 The ring formed by combining two of these is preferably a cycloalkyl group. 11 , R 12 , and R 13 The cycloalkyl group formed by bonding two of the above is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms. R 41 , R 42 , and R 43 In a cycloalkyl group formed by bonding two of the above, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

[0093] R 41 , R 42 , and R 43 The organic group represented by may further have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, or a monovalent organic group. Examples of the monovalent organic group include an alkyl group (having 1 to 4 carbon atoms), an alkoxy group (having 1 to 4 carbon atoms), an alkylcarbonyl group (having 2 to 5 carbon atoms), a halogenated alkyl group (having 1 to 4 carbon atoms) such as a trifluoromethyl group, a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms). The number of carbon atoms in the substituent is preferably 8 or less.

[0094] [ka]

[0095] In the general formula (5), Y5 represents a hydrogen atom, a fluorine atom, or an alkyl group. 51 , R 52 , and R 53 R each independently represents an organic group. 51 , R 52 , and R 53 Two of these may be bonded to each other to form a ring.

[0096] In the general formula (5), Y5 represents a hydrogen atom, a fluorine atom, or an alkyl group. Examples of the alkyl group represented by Y5 include the alkyl groups represented by Y4, and preferred examples are also the same. Y5 is preferably a hydrogen atom or a methyl group.

[0097] R in general formula (5) 51 , R 52 , and R 53 is R in general formula (4) 41 , R 42 , and R 43 The same applies to preferred examples.

[0098] [ka]

[0099] In the general formula (6), Y6 represents a hydrogen atom, a fluorine atom, or an alkyl group. 61 , R 62 , and R 63 R each independently represents an organic group. 61 , R 62 , and R 63 Two of these may be bonded to each other to form a ring.

[0100] In the general formula (6), Y6 represents a hydrogen atom, a fluorine atom, or an alkyl group. Examples of the alkyl group represented by Y6 include the alkyl groups represented by Y4, and preferred examples are also the same. Y6 is preferably a hydrogen atom or a methyl group.

[0101] R in general formula (6) 61 , R 62 , and R 63 is R in general formula (4) 41 , R 42 , and R 43 The same applies to preferred examples.

[0102] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (A).

[0103] [ka]

[0104] L1 represents a divalent linking group which may have a fluorine atom or an iodine atom, R1 represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom, and R2 represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom, provided that at least one of L1, R1, and R2 has a fluorine atom or an iodine atom. Examples of the divalent linking group represented by L1 which may have a fluorine atom or an iodine atom include -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, alkylene groups, cycloalkylene groups, alkenylene groups, arylene groups, etc.), and linking groups in which a plurality of these are linked together. Among these, L1 is preferably -CO-, an arylene group, or -arylene group-alkylene group having a fluorine atom or an iodine atom-, and more preferably -CO- or -arylene group-alkylene group having a fluorine atom or an iodine atom-. The arylene group is preferably a phenylene group. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0105] The alkyl group represented by R1 may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom, represented by R1, is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. The alkyl group represented by R1 may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0106] Examples of the leaving group represented by R2 which may have a fluorine atom or an iodine atom include leaving groups represented by the above formulae (Y1) to (Y4) which have a fluorine atom or an iodine atom.

[0107] The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by formula (AI).

[0108] [ka]

[0109] In formula (AI), Xa1 represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Rx1 to Rx3 each independently represent an alkyl group (straight-chain or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (straight-chain or branched), or an aryl group (monocyclic or polycyclic). However, when all of Rx1 to Rx3 are alkyl groups (straight-chain or branched), it is preferable that at least two of Rx1 to Rx3 are methyl groups. Two of Rx1 to Rx3 may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group).

[0110] The alkyl group represented by Xa1, which may have a substituent, is, for example, a methyl group or -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. 11 Examples of the monovalent organic group represented by the formula (I) include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, with an alkyl group having 3 or less carbon atoms being preferred, and a methyl group being more preferred. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0111] Examples of the divalent linking group for T include an alkylene group, an aromatic ring group, a -COO-Rt- group, and an -O-Rt- group, where Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

[0112] The alkyl group of Rx1 to Rx3 is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The cycloalkyl groups of Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The aryl group of Rx1 to Rx3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. The alkenyl group of Rx1 to Rx3 is preferably a vinyl group. The cycloalkyl group formed by combining two of Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Also preferred are polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Of these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferred. In the cycloalkyl group formed by combining two of Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. In the repeating unit represented by formula (AI), for example, Rx1 is a methyl group or an ethyl group, and Rx2 and Rx3 are bonded to form the above-mentioned cycloalkyl group.

[0113] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).The number of carbon atoms in the substituent is preferably 8 or less.

[0114] The repeating unit represented by formula (AI) is preferably an acid-decomposable (meth)acrylic acid tertiary alkyl ester repeating unit (a repeating unit in which Xa1 represents a hydrogen atom or a methyl group and T represents a single bond).

[0115] Specific examples of repeating units having an acid-decomposable group are shown below, but are not limited to these: In the formula, Xa1 represents H, CH3, CF3, or CH2OH, and Rxa and Rxb each independently represent a linear or branched alkyl group having 1 to 5 carbon atoms.

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] The resin (A) may have, as the repeating unit having an acid-decomposable group, a repeating unit having an acid-decomposable group containing an unsaturated bond. The repeating unit having an acid-decomposable group containing an unsaturated bond is preferably a repeating unit represented by formula (B).

[0122] [ka]

[0123] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent. L represents a single bond or a divalent linking group which may have a substituent. Ry1 to Ry3 each independently represent a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group, with the proviso that at least one of Ry1 to Ry3 represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group. Two of Ry1 to Ry3 may be bonded to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group).

[0124] The alkyl group represented by Xb, which may have a substituent, is, for example, a methyl group or -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, with an alkyl group having 3 or less carbon atoms being preferred, and a methyl group being more preferred. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0125] Examples of the divalent linking group for L include a -Rt- group, a -CO- group, a -COO-Rt- group, a -COO-Rt-CO- group, a -Rt-CO- group, and a -O-Rt- group, where Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, and an aromatic ring group is preferred. L is preferably a -Rt- group, a -CO- group, a -COO-Rt-CO- group, or a -Rt-CO- group, where Rt may have a substituent such as a halogen atom, a hydroxyl group, or an alkoxy group.

[0126] The alkyl groups Ry1 to Ry3 are preferably alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. The cycloalkyl groups of Ry1 to Ry3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The aryl group of Ry1 to Ry3 is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. The alkenyl group of Ry1 to Ry3 is preferably a vinyl group. The alkynyl group of Ry1 to Ry3 is preferably an ethynyl group. The cycloalkenyl groups of Ry1 to Ry3 are preferably monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, which have a structure containing a double bond in part thereof. The cycloalkyl group formed by combining two of Ry1 to Ry3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, etc. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. In the cycloalkyl group or cycloalkenyl group formed by combining two of Ry1 to Ry3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a carbonyl group, a group containing a heteroatom such as a -SO2- group or a -SO3- group, a vinylidene group, or a combination thereof. Furthermore, in these cycloalkyl groups or cycloalkenyl groups, one or more of the ethylene groups constituting the cycloalkane ring or cycloalkene ring may be replaced with a vinylene group. In the repeating unit represented by formula (B), for example, Ry1 is a methyl group, ethyl group, vinyl group, allyl group, or aryl group, and Ry2 and Ry3 are bonded to form the above-mentioned cycloalkyl group or cycloalkenyl group.

[0127] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).The number of carbon atoms in the substituent is preferably 8 or less.

[0128] The repeating unit represented by formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -CO- group), an acid-decomposable hydroxystyrene tertiary alkyl ether repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or an acid-decomposable styrene carboxylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -Rt-CO- group (Rt is an aromatic group)).

[0129] The content of the repeating units having an acid-decomposable group containing an unsaturated bond is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total repeating units in the resin (A), and the upper limit thereof is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less, based on the total repeating units in the resin (A).

[0130] Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond are shown below, but are not limited to these. In the formula, Xb and L1 represent any of the substituents and linking groups described above, Ar represents an aromatic group, R represents a substituent such as a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR'" or -COOR'"; R'" represents an alkyl group or a fluorinated alkyl group having 1 to 20 carbon atoms), or a carboxyl group, R' represents a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group, Q represents a heteroatom such as an oxygen atom, a carbonyl group, a group containing a heteroatom such as a -SO2- group or a -SO3- group, a vinylidene group, or a combination thereof, and n, m, and l represent integers of 0 or greater.

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] The content of the repeating unit (a2) having an acid-decomposable group is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on all repeating units in the resin (A).The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on all repeating units in the resin (A).

[0135] <Repeating unit (a3) ​​other than repeating units (a1) and (a2)> The resin (A) may contain at least one repeating unit selected from the group consisting of the following Group A: Group A: A group consisting of the following repeating units (20) to (25). (20) A repeating unit having an acid group, as described below (21) A repeating unit having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom, as described below. (22) A repeating unit having a lactone group, a sultone group, or a carbonate group, as described below. (23) A repeating unit having a photoacid generating group, which will be described later (24) A repeating unit represented by formula (V-1) or formula (V-2) described below: (25) Repeating units for reducing main chain mobility The repeating units represented by formulae (A) to (E), which will be described later, correspond to the repeating units for reducing the mobility of the main chain (25).

[0136] The resin (A) preferably has an acid group, and as described below, preferably contains a repeating unit having an acid group. The definition of the acid group will be explained later together with preferred embodiments of the repeating unit having an acid group. When the resin (A), i.e., the resin (A1), has an acid group, when the finally obtained resin (A1) is used in a resist composition together with a photoacid generator, the interaction between the resin (A1) and the acid generated from the photoacid generator is more excellent. As a result, the diffusion of the acid is further suppressed, and the cross-sectional shape of the formed pattern can be more rectangular.

[0137] Resin (A) may have at least one repeating unit selected from the group consisting of Group A. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, resin (A) preferably has at least one repeating unit selected from the group consisting of Group A. Resin (A) may contain at least one of a fluorine atom and an iodine atom. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, resin (A) preferably contains at least one of a fluorine atom and an iodine atom. When resin (A) contains both fluorine atoms and iodine atoms, resin (A) may have one repeating unit containing both fluorine atoms and iodine atoms, or resin (A) may contain both a repeating unit containing a fluorine atom and a repeating unit containing an iodine atom. Resin (A) may have a repeating unit having an aromatic group. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for EUV exposure, it is also preferable that Resin (A) have a repeating unit having an aromatic group. Resin (A) may have at least one repeating unit selected from the group consisting of Group B. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, resin (A) preferably has at least one repeating unit selected from the group consisting of Group B. When the resist composition is used as an actinic ray-sensitive or radiation-sensitive resin composition for ArF, it is preferable that the resin (A) contains neither fluorine atoms nor silicon atoms.

[0138] (Repeating unit having an acid group) The resin (A) may have a repeating unit having an acid group. The acid group preferably has a pKa of 13 or less. The acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10. When the resin (A) has an acid group with a pKa of 13 or less, the content of the acid group in the resin (A) is not particularly limited, but is often 0.2 to 6.0 mmol / g. Among these, 0.8 to 6.0 mmol / g is preferred, 1.2 to 5.0 mmol / g is more preferred, and 1.6 to 4.0 mmol / g is even more preferred. When the acid group content is within the above range, development proceeds well, and the formed pattern shape is excellent, and the resolution is also excellent. The acid group is preferably, for example, a carboxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group. In the hexafluoroisopropanol group, one or more (preferably one to two) fluorine atoms may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). The acid group thus formed, -C(CF3)(OH)-CF2-, is also preferred. One or more fluorine atoms may be substituted with a group other than a fluorine atom to form a ring containing -C(CF3)(OH)-CF2-. The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having a structure in which a polar group is protected with a group that is cleaved by the action of an acid, and a repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later. The repeating unit having an acid group may have a fluorine atom or an iodine atom.

[0139] Examples of the repeating unit having an acid group include the following repeating units.

[0140] [ka]

[0141] [ka]

[0142] The content of the repeating units having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less, based on all repeating units in the resin (A).

[0143] (Repeating units having neither an acid-decomposable group nor an acid group, and having a fluorine atom, a bromine atom, or an iodine atom) In addition to the repeating unit (a1) derived from monomer (i), the repeating unit (a2) having an acid-decomposable group, and the repeating unit having an acid group, resin (A) may also have a repeating unit having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom (hereinafter also referred to as unit X). The repeating unit having neither an acid-decomposable group nor an acid group, but having a fluorine atom, a bromine atom, or an iodine atom is preferably different from other types of repeating units belonging to Group A, such as the repeating units having a lactone group, a sultone group, or a carbonate group and the repeating units having a photoacid-generating group, which will be described later.

[0144] The unit X is preferably a repeating unit represented by formula (C).

[0145] [ka]

[0146] L5 represents a single bond or an ester group. R9 represents a hydrogen atom or an alkyl group which may have a fluorine atom or an iodine atom. R 10 represents a hydrogen atom, an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group which is a combination of these.

[0147] Examples of repeating units having a fluorine atom or an iodine atom are shown below.

[0148] [ka]

[0149] The content of units X is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all repeating units in resin (A), and the upper limit is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less, based on all repeating units in resin (A).

[0150] The total content of repeating units containing at least one of a fluorine atom, a bromine atom, and an iodine atom in the repeating units of the resin (A) is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 40 mol% or more, based on all repeating units of the resin (A). There is no particular upper limit, but it is, for example, 100 mol% or less based on all repeating units of the resin (A). Examples of the repeating unit containing at least one of a fluorine atom, a bromine atom, and an iodine atom include a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and an acid-decomposable group, a repeating unit having a fluorine atom, a bromine atom, or an iodine atom and an acid group, and a repeating unit having a fluorine atom, a bromine atom, or an iodine atom.

[0151] (Repeating units having a lactone group, a sultone group, or a carbonate group) The resin (A) may have a repeating unit (hereinafter also referred to as "unit Y") having at least one type selected from the group consisting of a lactone group, a sultone group, and a carbonate group. It is also preferred that the unit Y does not have a hydroxyl group or an acid group such as a hexafluoropropanol group.

[0152] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or the sultone structure is preferably a 5- to 7-membered cyclic lactone structure or a 5- to 7-membered cyclic sultone structure. Among these, a 5- to 7-membered cyclic lactone structure is more preferably fused with another ring structure to form a bicyclo structure or a spiro structure, or a 5- to 7-membered cyclic sultone structure is more preferably fused with another ring structure to form a bicyclo structure or a spiro structure. Resin (A) preferably has a repeating unit having a lactone group or sultone group formed by removing one or more hydrogen atoms from a ring atom of a lactone structure represented by any one of the following formulae (LC1-1) to (LC1-21) or a sultone structure represented by any one of the following formulae (SL1-1) to (SL1-3), and the lactone group or sultone group may be directly bonded to the main chain. For example, the ring atom of the lactone group or sultone group may constitute the main chain of Resin (A).

[0153] [ka]

[0154] The lactone structure or sultone structure may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple Rb2 may be different from each other, or multiple Rb2 may be bonded to form a ring.

[0155] Examples of repeating units having a group containing a lactone structure represented by any one of formulas (LC1-1) to (LC1-21) or a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) include repeating units represented by the following formula (AI):

[0156] [ka]

[0157] In formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred examples of the substituent that the alkyl group of Rb0 may have include a hydroxyl group and a halogen atom. Examples of the halogen atom of Rb0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb0 is preferably a hydrogen atom or a methyl group. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent linking group combining these. Among these, Ab is preferably a single bond or a linking group represented by -Ab1-CO2-. Ab1 is a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group. V represents a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any one of formulae (LC1-1) to (LC1-21), or a group obtained by removing one hydrogen atom from a ring member atom of a sultone structure represented by any one of formulae (SL1-1) to (SL1-3).

[0158] When optical isomers exist in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. One optical isomer may be used alone, or multiple optical isomers may be used in combination. When one optical isomer is primarily used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

[0159] The carbonate group is preferably a cyclic carbonate group. The repeating unit having a cyclic carbonate group is preferably a repeating unit represented by the following formula (A-1).

[0160] [ka]

[0161] In formula (A-1), R A 1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably a methyl group). n represents an integer of 0 or more. R A 2represents a substituent. When n is 2 or more, multiple R A 2 may be the same or different. A represents a single bond or a divalent linking group. The divalent linking group is preferably an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent linking group formed by combining these. Z represents an atomic group that forms a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

[0162] Examples of the unit Y are shown below: In the formula, Rx represents a hydrogen atom, -CH3, -CH2OH, or -CF3.

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] The content of the unit Y is preferably 1 mol% or more, more preferably 10 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on all repeating units in the resin (A).

[0167] (Repeating unit having a photoacid generating group) The resin (A) may contain, as a repeating unit other than those mentioned above, a repeating unit having a group that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as a "photoacid-generating group"). Examples of the repeating unit having a photoacid generating group include a repeating unit represented by formula (4).

[0168] [ka]

[0169] R 41 represents a hydrogen atom or a methyl group. 41 represents a single bond or a divalent linking group. 42 represents a divalent linking group. 40 represents a structural moiety that is decomposed by irradiation with actinic rays or radiation to generate an acid in the side chain. Examples of repeating units having a photoacid generating group are shown below.

[0170] [ka]

[0171] Other examples of the repeating unit represented by formula (4) include the repeating units described in paragraphs

[0094] to

[0105] of JP 2014-041327 A and the repeating unit described in paragraph

[0094] of WO 2018 / 193954 A.

[0172] The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less, based on all repeating units in the resin (A).

[0173] (Repeating unit represented by formula (V-1) or the following formula (V-2)) The resin (A) may have a repeating unit represented by the following formula (V-1) or the following formula (V-2). The repeating units represented by the following formula (V-1) and the following formula (V-2) are preferably repeating units different from the repeating units described above.

[0174] [ka]

[0175] During the ceremony, R6 and R7 each independently represent a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. The alkyl group is preferably a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. n3 represents an integer of 0 to 6. n4 represents an integer of 0 to 4. X4 is a methylene group, an oxygen atom, or a sulfur atom. Examples of the repeating unit represented by formula (V-1) or (V-2) are shown below. Examples of the repeating unit represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of WO 2018 / 193954.

[0176] (Repeating unit to reduce the mobility of the main chain) Resin (A) and the final resin (A1) preferably have a high glass transition temperature (Tg) in order to prevent excessive diffusion of the generated acid or pattern collapse during development. Tg is preferably higher than 90°C, more preferably higher than 100°C, even more preferably higher than 110°C, and particularly preferably higher than 125°C. In order to achieve a superior dissolution rate in a developer, Tg is preferably 400°C or lower, more preferably 350°C or lower. In this specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter referred to as "Tg of a repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting of each repeating unit contained in the polymer is calculated using the Bicerano method. Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg for each mass proportion is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these values ​​are summed to obtain the Tg (°C) of the polymer. The Bicerano method is described in Prediction of polymer properties, Marcel Dekker Inc., New York (1993). Calculation of Tg by the Bicerano method can be performed using polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0177] In order to increase the Tg of the resin (A) (preferably to make the Tg exceed 90°C), it is preferable to reduce the mobility of the main chain of the resin (A). Methods for reducing the mobility of the main chain of the resin (A) include the following methods (a) to (e). (a) Introduction of bulky substituents into the main chain (b) Introduction of multiple substituents into the main chain (c) Introduction of a substituent group that induces interactions between resins (A) near the main chain (d) Main chain formation in a cyclic structure (e) Linking of cyclic structures to the main chain The resin (A) preferably has a repeating unit that exhibits a homopolymer Tg of 130° C. or higher. The repeating units exhibiting a homopolymer Tg of 130° C. or higher are not particularly limited as long as they are repeating units exhibiting a homopolymer Tg of 130° C. or higher as calculated by the Bicerano method. Depending on the type of functional group in the repeating units represented by formulas (A) to (E) described below, they may be considered as repeating units exhibiting a homopolymer Tg of 130° C. or higher.

[0178] One example of a specific means for achieving the above (a) is to introduce a repeating unit represented by formula (A) into resin (A).

[0179] [ka]

[0180] Formula (A), R A represents a group containing a polycyclic structure. x represents a hydrogen atom, a methyl group, or an ethyl group. The group containing a polycyclic structure is a group containing a plurality of ring structures, and the plurality of ring structures may or may not be condensed. Specific examples of the repeating unit represented by formula (A) include those described in paragraphs

[0107] to

[0119] of WO 2018 / 193954.

[0181] One example of a specific means for achieving the above (b) is a method of introducing a repeating unit represented by formula (B) into resin (A).

[0182] [ka]

[0183] In formula (B), R b1 ~R b4 each independently represents a hydrogen atom or an organic group, R b1 ~R b4 At least two of these represent organic groups. When at least one of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, the types of the other organic groups are not particularly limited. Furthermore, when none of the organic groups has a ring structure directly connected to the main chain in the repeating unit, at least two of the organic groups are substituents having three or more constituent atoms excluding hydrogen atoms. Specific examples of the repeating unit represented by formula (B) include those described in paragraphs

[0113] to

[0115] of WO 2018 / 193954.

[0184] One example of a specific means for achieving the above (c) is a method of introducing a repeating unit represented by formula (C) into resin (A).

[0185] [ka]

[0186] In formula (C), R c1 ~R c4 each independently represents a hydrogen atom or an organic group, R c1 ~R c4 At least one of the groups is a group containing a hydrogen-bonding hydrogen atom within three atoms from the main chain carbon. In particular, in order to induce interaction between the main chains of the resin (A), it is preferable to have a hydrogen-bonding hydrogen atom within two atoms (closer to the main chain). Specific examples of the repeating unit represented by formula (C) include those described in paragraphs

[0119] to

[0121] of WO 2018 / 193954.

[0187] One example of a specific means for achieving the above (d) is to introduce a repeating unit represented by formula (D) into resin (A).

[0188] [ka]

[0189] In formula (D), "Cyclic" represents a group that forms a main chain with a cyclic structure. The number of atoms constituting the ring is not particularly limited. Specific examples of the repeating unit represented by formula (D) include those described in paragraphs

[0126] to

[0127] of WO 2018 / 193954.

[0190] One example of a specific means for achieving the above (e) is to introduce a repeating unit represented by formula (E) into resin (A).

[0191] [ka]

[0192] In formula (E), each Re independently represents a hydrogen atom or an organic group, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, each of which may have a substituent. "Cyclic" refers to a cyclic group containing carbon atoms in the main chain. There are no particular restrictions on the number of atoms contained in the cyclic group. Specific examples of the repeating unit represented by formula (E) include those described in paragraphs

[0131] to

[0133] of WO 2018 / 193954.

[0193] In addition to the repeating structural units described above, the resin (A) may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0194] The weight average molecular weight of the resin (A), as measured by GPC in terms of polystyrene, is preferably 30,000 or less, more preferably from 1,000 to 30,000, still more preferably from 3,000 to 30,000, and particularly preferably from 5,000 to 15,000. The polydispersity (molecular weight distribution) of the resin (A) is preferably from 1 to 5, more preferably from 1 to 3, even more preferably from 1.2 to 3.0, and particularly preferably from 1.2 to 2.0. The smaller the polydispersity, the better the resolution and resist shape, and further the smoother the sidewalls of the resist pattern and the better the roughness.

[0195] <Polymerization method> In the step (I), a group of monomers including the above-mentioned monomer (i) is polymerized to obtain a polymer (resin (A)). The polymerization method for the resin (A) is not particularly limited, and known methods can be used, such as radical polymerization. Examples of radical polymerization methods include bulk polymerization, in which a monomer species and an initiator are dissolved in a solvent and polymerized by heating, and dropwise polymerization, in which a solution of the monomer species and the initiator is added dropwise to a heated solvent over 1 to 10 hours, with dropwise polymerization being preferred.

[0196] The monomer species essentially includes the above-mentioned monomer (i), and, if necessary, raw material monomers for the repeating units (a2) and (a3), such as monomers represented by any of the above-mentioned general formulas (4) to (6). The ratio of each monomer used may be adjusted so that the repeating units derived from each monomer obtained by polymerization fall within the preferred range of the content of each repeating unit in the above-mentioned resin (A).

[0197] Examples of reaction solvents include ethers such as tetrahydrofuran, 1,4-dioxane, and diisopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate; amides such as dimethylformamide and dimethylacetamide; propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, methanol, ethyl lactate, and cyclohexanone. Among these, from the viewpoint of deprotection reactivity when the solution containing resin (A) obtained at the end of step (I) is used as is in the subsequent step (II), propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, methanol, ethyl lactate, cyclohexanone, and the like are preferred.

[0198] The polymerization reaction is preferably carried out under an inert gas atmosphere such as nitrogen and / or argon. Commercially available radical initiators (e.g., azo initiators and peroxides) can be used as the polymerization initiator. Azo initiators are preferred as the radical initiator, and azo initiators having an ester group, a cyano group, or a carboxyl group are more preferred. Specific examples of the polymerization initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, and dimethyl 2,2'-azobis(2-methylpropionate). If desired, the polymerization initiator is added additionally or in portions, and after the reaction is completed, the resin (A) is recovered. The concentration of the reactant is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. The reaction temperature is not particularly limited, but is generally preferably 10 to 150°C, more preferably 30 to 120°C, and even more preferably 60 to 100°C.

[0199] Examples of purification methods that can be used include: a liquid extraction method in which residual monomers and / or oligomers are removed by washing with water and / or by combining an appropriate solvent; a solution-state purification method such as ultrafiltration in which compounds having a specific molecular weight or less are extracted and removed; a reprecipitation method in which a solution containing a resin precursor is dropped into a poor solvent to solidify the resin precursor in the poor solvent, thereby removing residual monomers, etc.; and a solid-state purification method in which the filtered resin precursor slurry is washed with a poor solvent. Note that the solution containing resin (A) may be used directly in step (II) without undergoing the above purification procedures.

[0200] [Step (II)] The production method of the present invention includes, as step (II), a step of solvolyzing the protective moiety, which is protected with the structure represented by general formula (1), possessed by the repeating unit (a1) in the polymer (resin (A)) obtained in step (I) to obtain a repeating unit (a0) having a phenolic hydroxyl group. Solvolysis refers to the decomposition of a solute by reaction with a solvent.

[0201] <Solvent> The solvent used in solvolysis is preferably a protic solvent, such as a monohydric or polyhydric alcohol, water, or the like.

[0202] Examples of the monohydric alcohol include alkyl alcohols having 1 to 8 carbon atoms, such as methanol, ethanol, isopropyl alcohol, n-butanol, n-hexanol, n-octanol, tert-butyl alcohol, and isobutyl alcohol; benzyl alcohol; and 1-methoxy-2-propanol. Examples of polyhydric alcohols include ethylene glycol and propylene glycol.

[0203] The solvent used in the solvolysis may be a mixed solvent of the above-mentioned protic solvent and another organic solvent.

[0204] As the solvent to be used in the solvolysis, alcohols such as methanol, 1-methoxy-2-propanol, propylene glycol monomethyl ether, and the like, or mixed solvents of alcohols with other solvents are preferred from the viewpoints of reactivity and solubility.

[0205] <Basic compounds> The solvolysis is preferably carried out in the presence of a basic compound, such as an amine compound, an alkali metal hydroxide, an alkali metal alkoxide, or an alkali metal carbonate.

[0206] Examples of the amine compound include triethylamine, trimethylamine, tributylamine, t-butylamine, diisopropylethylamine, pyridine, N-methylpiperazine, 4-dimethylaminopyridine, 3-diethylaminopropylamine, pyrrole, 1,2-diaminopropane, piperidine, trioctylamine, 2-ethylhexylamine, dibenzylamine, diazabicycloundecene, and ammonia.

[0207] Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the alkali metal alkoxide include sodium methoxide. Examples of the alkali metal carbonate include sodium carbonate and cesium carbonate.

[0208] The basic compound is preferably an amine compound, and from the viewpoints of reactivity and ease of purification in a subsequent step, triethylamine, 4-dimethylaminopyridine, and diazabicycloundecene are more preferred.

[0209] <Solvolysis reaction> Solvolysis can be carried out, for example, by adding the above-mentioned protic solvent and basic compound to a solution containing the polymer (resin (A)) obtained in the above-mentioned step (I) and mixing the mixture with stirring.

[0210] The amount of the protic solvent to be added is preferably 5 equivalents or more per equivalent of the protecting group. When a basic compound is added, the amount added is preferably 1 equivalent or more per equivalent of the protecting group.

[0211] The reaction temperature for the solvolysis reaction is usually in the range of 0° C. to 150° C., and preferably in the range of 20° C. to 90° C. The reaction temperature may be adjusted appropriately depending on the type of polymer (resin (A)) used, the type of protic solvent, and the type of basic compound. The reaction time for the solvolysis reaction is about 0.5 to 8 hours, preferably in the range of 1 to 4 hours.

[0212] In the present invention, since the phenolic hydroxyl group is protected by the specific structure represented by the above general formula (1), deprotection by solvolysis reaction can be carried out in a short time. Furthermore, since no acidic compound is required for the deprotection reaction, there is no need to limit the types of raw material monomers used in the copolymerization to those with high acid stability, which increases the flexibility of the resin composition.Furthermore, there is no problem of corrosion of the reaction equipment during production.

[0213] [Step (III)] The resin (A1) containing the repeating unit (a0) having a phenolic hydroxyl group is obtained by the above steps (I) and (II). The production method of the present invention preferably includes step (III), in which the polymer obtained after step (II) is brought into contact with an acidic aqueous solution. By contacting the polymer with an acidic aqueous solution, impurities with high water solubility in the solution containing the polymer after completion of step (II) can be removed. Furthermore, when a basic compound is used in step (II), the phenolic hydroxyl groups in the polymer are converted into a pair salt (-O - M + ;M + is a cation derived from a basic compound), which can be further converted to an -OH group.

[0214] Examples of the acidic aqueous solution include an aqueous hydrochloric acid solution, an aqueous sulfuric acid solution, an aqueous acetic acid solution, and an aqueous oxalic acid solution, and it is preferable to use an aqueous hydrochloric acid solution.

[0215] The amount of acidic aqueous solution used should be such that it contains an amount of acid capable of converting the counter salt to an -OH group, and it is preferable that it contains at least 1 equivalent of acid per equivalent of the basic compound used.

[0216] The contact with the acidic aqueous solution can be carried out, for example, by adding the acidic aqueous solution to the solution containing the polymer after the completion of step (II) and stirring and mixing. In addition to the acidic aqueous solution, a solvent may be added as needed. Examples of the solvent include the above-mentioned protic solvents.

[0217] After contact with the acidic aqueous solution, a solvent capable of dissolving the solid precipitated by the contact is further added to dissolve the solid, and the organic layer is extracted, thereby obtaining a solution containing the desired resin (A1).

[0218] The solution containing the resin (A1) may be further subjected to a conventional purification treatment, for example, washing with an acidic aqueous solution or water to further remove impurities.

[0219] [Step (IV)] The production method of the present invention preferably includes, as step (IV), a step of mixing the solution containing the polymer after step (II) with a poor solvent for the polymer. By mixing with the poor solvent, the resin (A1) can be reprecipitated and purified.

[0220] As the solution containing the polymer after the step (II), it is preferable to use the solution after the step (III). That is, it is preferable to carry out the step (IV) after the step (III).

[0221] The poor solvent may be, for example, a hydrocarbon solvent, an ether, an ester, an alcohol, a ketone, water, or the like, although it depends on the type of polymer used. One poor solvent may be used, or two or more poor solvents may be mixed. Furthermore, the poor solvent may be a mixed solvent with a solvent other than those mentioned above.

[0222] The reprecipitated resin (A1) can be collected by filtration to obtain a solid resin (A1). The resin (A1) may be further subjected to a conventional purification treatment, for example, by washing with the poor solvent to further remove impurities.

[0223] <<Resin (A1)>> The above-described production method of the present invention allows for the efficient production of a resin (A1) containing a repeating unit (a0) having a phenolic hydroxyl group. The preferred ranges for the weight-average molecular weight and polydispersity of the resulting resin (A1) are the same as those for the weight-average molecular weight and polydispersity of the resin (A). The preferred contents of the repeating unit (a0), the repeating unit (a2), and the various repeating units (a3) ​​relative to the total repeating units in the resin (A1) are the same as those for the repeating unit (a1), the repeating unit (a2), and the various repeating units (a3) ​​relative to the total repeating units in the resin (A).

[0224] [Actinic ray-sensitive or radiation-sensitive resin composition] The resin (A1) obtained by the production method of the present invention can be suitably used in an actinic ray-sensitive or radiation-sensitive resin composition. The actinic ray-sensitive or radiation-sensitive resin composition is typically a resist composition, and may be a positive resist composition or a negative resist composition. The resist composition may be a resist composition for alkali development or a resist composition for organic solvent development. The resist composition may be a chemically amplified resist composition or a non-chemically amplified resist composition. The resist composition is typically a chemically amplified resist composition.

[0225] In addition to the resin (A1), the resist composition may contain various components that are typically used in resist compositions, such as a photoacid generator, an acid diffusion controller, a hydrophobic resin, a surfactant, a solvent, and other additives.

[0226] <Photoacid generator> The resist composition may contain a photoacid generator (B). The photoacid generator (B) may be in the form of a low molecular weight compound, or may be incorporated into a part of a polymer (for example, the above-mentioned resin (A1)). In addition, the form of a low molecular weight compound and the form of being incorporated into a part of a polymer (for example, the above-mentioned resin (A1)) may be used in combination. In this specification, the photoacid generator (B) is preferably in the form of a low molecular weight compound.

[0227] Examples of the photoacid generator (B) include "M + X - The compound is preferably an onium salt that generates an organic acid upon exposure to light. Examples of the organic acid include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimide acids, bis(alkylsulfonyl)imide acids, and tris(alkylsulfonyl)methide acids.

[0228] "M + X - In the compound represented by ", M + represents an organic cation. The organic cation is not particularly limited, and the valence of the organic cation may be monovalent or divalent or higher.

[0229] "M + X - In the compound represented by ", X - represents an organic anion. The organic anion is not particularly limited, and examples thereof include monovalent or divalent or higher organic anions. As the organic anion, an anion having a significantly low ability to cause a nucleophilic reaction is preferred, and a non-nucleophilic anion is more preferred.

[0230] The photoacid generator is not particularly limited, and any known photoacid generator can be used, such as those described in paragraphs

[0368] to

[0377] of JP 2014-41328 A, paragraphs

[0240] to

[0262] of JP 2013-228681 A (corresponding to paragraph

[0339] of U.S. Patent Application Publication No. 2015 / 004533), and paragraphs

[0144] to

[0173] of JP 2019-045864 A.

[0231] <Acid diffusion controller (C)> The resist composition may contain an acid diffusion controller. The acid diffusion controller traps the acid generated from the photoacid generator or the like during exposure, and acts as a quencher that inhibits the reaction of the acid-decomposable resin in the unexposed areas caused by excess acid generated. The type of acid diffusion controller is not particularly limited, and examples thereof include basic compounds (CA), low molecular weight compounds (CB) having a nitrogen atom and a group that is cleaved by the action of an acid, and compounds (CC) whose acid diffusion control ability is reduced or eliminated by irradiation with actinic rays or radiation. Examples of the compound (CC) include an onium salt compound (CD) that is a weak acid relative to the photoacid generator, and a basic compound (CE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation. Specific examples of basic compounds (CA) include those described in paragraphs

[0132] to

[0136] of WO 2020 / 066824. Specific examples of basic compounds (CE) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation include those described in paragraphs

[0137] to

[0155] of WO 2020 / 066824 and those described in paragraph

[0164] of WO 2020 / 066824. Specific examples of low molecular weight compounds (CB) having a nitrogen atom and a group that is released by the action of an acid include those described in paragraphs

[0156] to

[0163] of WO 2020 / 066824. Specific examples of onium salt compounds (CD) that are relatively weak acids compared to photoacid generators include those described in paragraphs

[0305] to

[0314] of WO 2020 / 158337.

[0232] In addition to the above, known compounds disclosed in, for example, U.S. Patent Application Publication No. 2016 / 0070167A1, paragraphs

[0627] to

[0664] , U.S. Patent Application Publication No. 2015 / 0004544A1, paragraphs

[0095] to

[0187] , U.S. Patent Application Publication No. 2016 / 0237190A1, paragraphs

[0403] to

[0423] , and U.S. Patent Application Publication No. 2016 / 0274458A1, paragraphs

[0259] to

[0328] can be suitably used as the acid diffusion controller.

[0233] <Hydrophobic resin (D)> The resist composition may further contain a hydrophobic resin that is different from the resin (A1). From the viewpoint of uneven distribution in the film surface layer, the hydrophobic resin preferably has one or more of a fluorine atom, a silicon atom, and a CH3 partial structure contained in a side chain portion of the resin, and more preferably has two or more of these. The hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be contained in the main chain of the resin or may be substituted on the side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of WO 2020 / 004306.

[0234] <Surfactant (E)> The resist composition may contain a surfactant, which can provide a pattern with superior adhesion and fewer development defects. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of fluorine-based and / or silicone-based surfactants include surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 193954.

[0235] <Solvent (F)> The resist composition preferably contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, chain ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2). Details of the components (M1) and (M2) are described in paragraphs

[0218] to

[0226] of WO 2020 / 004306, the contents of which are incorporated herein by reference.

[0236] <Other additives> The resist composition may further contain a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1000 or less, or an alicyclic or aliphatic compound containing a carboxyl group).

[0237] A resist composition containing the resin (A1) of this specification is suitably used as a photosensitive composition for EB exposure or a photosensitive composition for EUV exposure. [Example]

[0238] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0239] <Synthesis Example 1: Synthesis of Monomer M-80>

[0240] [ka]

[0241] M-80-a (15.0 g), triethylamine (18.7 g), and 4-dimethylaminopyridine (DMAP) (0.11 g) were dissolved in methylene chloride (dichloromethane) (300.0 g). The reaction mixture was cooled in an ice bath, and then 3,5-bis(trifluoromethyl)benzoyl chloride (26.6 g) was added. The mixture was stirred at room temperature (25°C) for 2 hours, after which water (100 g) was added. The solvent was distilled off from the organic layer to obtain M-80-b (35.7 g, 99% yield).

[0242] [ka]

[0243] M-80-b (10.0 g) and N-bromosuccinimide (NBS) (11.7 g) were dissolved in ethyl acetate (AcOEt) (80.0 g). The mixture was stirred at 80°C for 2 hours, diluted with ethyl acetate (200 mL), and washed with saturated aqueous sodium bicarbonate (150 mL) and distilled water (150 mL). The solvent was removed from the organic layer to give M-80-c (17.4 g) (yield 99%).

[0244] [ka]

[0245] M-80-c (17.4 g) and 1.2 mol / L potassium iodide aqueous solution (130 mL) were added to acetone (300.0 g). After stirring the mixture for 2 hours, ethyl acetate (300 mL) was added, the organic layer was washed with water (300 mL), and the solvent was distilled off. The crude product was recrystallized from methanol to obtain monomer M-80 (7.6 g) (yield 61%).

[0246] Monomer (M-80) 1 The results of H-NMR measurements are shown below. 1 H-NMR(CDCl3):δ=8.76(s,2H),8.20(s,1H),7.64-7.76(m,3H),7.54(t,1H),7.37(d,1H),7.07(dd,2H)

[0247] <Synthesis Example 2: Synthesis of Monomer M-81>

[0248] [ka]

[0249] M-80-a (15.0 g), triethylamine (18.7 g), and 4-dimethylaminopyridine (DMAP) (0.11 g) were dissolved in methylene chloride (dichloromethane) (300.0 g). The reaction mixture was cooled in an ice bath, and then 4-nitrobenzoyl chloride (17.2 g) was added. The mixture was stirred at room temperature (25°C) for 2 hours, after which water (100 g) was added. The solvent was distilled off from the organic layer to obtain M-81-b (27.8 g, 99% yield).

[0250] [ka]

[0251] M-81-b (10.0 g) and N-bromosuccinimide (NBS) (11.7 g) were dissolved in ethyl acetate (AcOEt) (80.0 g). The mixture was stirred at 80°C for 2 hours, diluted with ethyl acetate (200 mL), and washed with saturated aqueous sodium bicarbonate (150 mL) and distilled water (150 mL). The solvent was removed from the organic layer to give M-81-c (14.6 g) (yield 99%).

[0252] [ka]

[0253] M-81-c (14.6 g) and 1.2 mol / L potassium iodide aqueous solution (130 mL) were added to acetone (300.0 g). After stirring the mixture for 2 hours, ethyl acetate (300 mL) was added, the organic layer was washed with water (300 mL), and the solvent was distilled off. The crude product was recrystallized from methanol to obtain monomer M-81 (5.9 g) (yield 61%).

[0254] Monomer (M-81) 1 The results of H-NMR measurements are shown below. 1H-NMR(CDCl3):δ=8.46-8.54(m,2H),8.38-8.46(m,2H),7.75(d,1H),7.68(t,2H),7.54(dd,1H),7.39(d,1H),7.07(dd,2H)

[0255] <Synthesis Example 3: Synthesis of Monomer M-89>

[0256] [ka]

[0257] 4-Acetoxystyrene (500 g) was dissolved in ethyl acetate (929 g). The reaction solution was cooled to -15°C, and then a 28 wt% solution of sodium methoxide in methanol (238 g) was added. After stirring at 5°C or below for 1 hour, 1 mol / L aqueous hydrochloric acid (800 mL) was added and the organic layer was extracted. The organic layer was washed twice with 1 mol / L aqueous hydrochloric acid (500 mL) and then five times with distilled water (500 mL). The organic layer was concentrated to obtain 730 g of a 50 wt% solution of 4-hydroxystyrene in ethyl acetate (yield 99%).

[0258] [ka]

[0259] A 50 wt% ethyl acetate solution of 4-hydroxystyrene (60.0 g), triethylamine (53.0 g), and 4-dimethylaminopyridine (DMAP) (0.31 g) were dissolved in methylene chloride (dichloromethane) (300.0 g). The reaction mixture was cooled in an ice bath, and then 3,5-bis(trifluoromethyl)benzoyl chloride (72.5 g) was added. The mixture was stirred at room temperature (25°C) for 2 hours, followed by the addition of water (100 g). The solvent was removed from the organic layer, and column purification (eluent: hexane / ethyl acetate) yielded M-89 (70 g, 78% yield).

[0260] Monomer (M-89) 1 The results of H-NMR measurements are shown below. 1 H-NMR(CDCl3):δ=8.76(s,2H),8.20(s,1H),7.43-7.50(m,2H),7.08-7.14(m,2H),6.70(dd,1H),5.70(d,1H),5.23(d,1H)

[0261] <Synthesis Example 4: Synthesis of Resin A-1-1> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 51 g of a monomer represented by the following formula M-80 (Monomer (M-80)), 7 g of a monomer represented by the following formula M-4 (Monomer (M-4)), 42 g of a monomer represented by the following formula M-33 (Monomer (M-33)), 186 g of cyclohexanone, and 5.9 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-1-a solution.

[0262] [ka]

[0263] Methanol (80 g) and triethylamine (61 g) were added to the resulting A-1-1-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L hydrochloric acid aqueous solution (3000 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a mixed solution of heptane / ethyl acetate = 9 / 1 (mass ratio) (hereinafter, the ratio in the mixed solution is mass ratio unless otherwise specified) and then filtered. The obtained solid was reslurried and washed with a mixed solution of heptane / ethyl acetate = 9 / 1, filtered, and vacuum dried to obtain 63 g of resin A-1-1.

[0264] 13The composition ratio (molar percentage ratio; corresponding from left to right) of each repeating unit measured by C-NMR (nuclear magnetic resonance) was 34 / 8 / 58. The weight average molecular weight (Mw) was 5,800 and the polydispersity (Mw / Mn) was 1.58. The weight average molecular weight (Mw) and polydispersity (Mw / Mn) were measured by GPC (carrier: tetrahydrofuran (THF)) (amounts calculated as polystyrene).

[0265] [ka]

[0266] <Synthesis Example 5: Synthesis of Resin A-1-2> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 56 g of a monomer represented by the following formula M-89 (Monomer (M-89)), 13 g of a monomer represented by the following formula M-4 (Monomer (M-4)), 31 g of a monomer represented by the following formula M-31 (Monomer (M-31)), 192 g of cyclohexanone, and 5.9 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-2-a solution.

[0267] [ka]

[0268] Methanol (100 g) and triethylamine (63 g) were added to the resulting A-1-2-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L hydrochloric acid aqueous solution (3750 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixed solution and then filtered. The resulting solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixed solution, filtered, and vacuum dried to obtain 54 g of resin A-1-2.

[0269] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 40 / 13 / 47. The weight average molecular weight (Mw) was 6500, and the polydispersity (Mw / Mn) was 1.60.

[0270] [ka]

[0271] <Synthesis Example 6: Synthesis of Resin A-1-3> Cyclohexanone (27 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 32 g of a monomer represented by the following formula M-81 (monomer (M-81)), 17 g of a monomer represented by the following formula M-6 (monomer (M-6)), 51 g of a monomer represented by the following formula M-31 (monomer (M-31)), 88 g of cyclohexanone, and 9.2 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-3-a solution.

[0272] [ka]

[0273] Methanol (65 g) and triethylamine (41 g) were added to the resulting A-1-3-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L hydrochloric acid aqueous solution (2500 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixed solution and then filtered. The obtained solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixed solution, filtered, and vacuum dried to obtain 54 g of resin A-1-3.

[0274] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 22 / 12 / 66. The weight average molecular weight (Mw) was 7100 and the polydispersity (Mw / Mn) was 1.60.

[0275] [ka]

[0276] <Synthesis Example 7: Synthesis of Resin A-1-4> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 52 g of a monomer represented by the following formula M-89 (Monomer (M-89)), 14 g of a monomer represented by the following formula M-80 (Monomer (M-80)), 34 g of a monomer represented by the following formula M-31 (Monomer (M-31)), 170 g of cyclohexanone, and 5.6 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-4-a solution.

[0277] [ka]

[0278] Methanol (114 g) and triethylamine (72 g) were added to the resulting A-1-4-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L hydrochloric acid aqueous solution (4300 mL) were added and stirred for 30 minutes. Ethyl acetate (2000 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixed solution and then filtered. The resulting solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixed solution, filtered, and vacuum dried to obtain 50 g of resin A-1-4.

[0279] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 38 / 9 / 53. The weight average molecular weight (Mw) was 6,800 and the polydispersity (Mw / Mn) was 1.56.

[0280] [ka]

[0281] <Synthesis Example 8: Synthesis of Resin A-1-1B> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 51 g of a monomer represented by the following formula M-80 (Monomer (M-80)), 7 g of a monomer represented by the following formula M-4 (Monomer (M-4)), 42 g of a monomer represented by the following formula M-33 (Monomer (M-33)), 186 g of cyclohexanone, and 5.9 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-1-a solution.

[0282] [ka]

[0283] Methanol (80 g), triethylamine (61 g), and 4-dimethylaminopyridine (10 g) were added to the resulting A-1-1-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L hydrochloric acid solution (3000 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixture and then filtered. The resulting solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixture, filtered, and vacuum dried to obtain 59 g of resin A-1-1B.

[0284] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 34 / 8 / 58. The weight average molecular weight (Mw) was 6100, and the polydispersity (Mw / Mn) was 1.55.

[0285] [ka]

[0286] <Synthesis Example 9: Synthesis of Resin A-1-1C> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 51 g of a monomer represented by the following formula M-80 (Monomer (M-80)), 7 g of a monomer represented by the following formula M-4 (Monomer (M-4)), 42 g of a monomer represented by the following formula M-33 (Monomer (M-33)), 186 g of cyclohexanone, and 5.9 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-1-a solution.

[0287] [ka]

[0288] 1-Methoxy-2-propanol (80 g), methanol (40 g), triethylamine (51 g), and diazabicycloundecene (10 g) were added to the resulting A-1-1-a solution and stirred at 80°C for 3 hours. After stirring, methanol (100 g) and 0.2 mol / L aqueous hydrochloric acid (3000 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L aqueous hydrochloric acid (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixture and then filtered. The resulting solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixture, filtered, and vacuum dried to obtain 59 g of Resin A-1-1C.

[0289] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 34 / 8 / 58. The weight average molecular weight (Mw) was 6100, and the polydispersity (Mw / Mn) was 1.55.

[0290] [ka]

[0291] <Synthesis Example 10: Synthesis of Resin A-1-1D> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 51 g of a monomer represented by the following formula M-80 (Monomer (M-80)), 7 g of a monomer represented by the following formula M-4 (Monomer (M-4)), 42 g of a monomer represented by the following formula M-33 (Monomer (M-33)), 186 g of cyclohexanone, and 5.9 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A-1-1-a solution.

[0292] [ka]

[0293] 1-Methoxy-2-propanol (80 g) and triethylamine (61 g) were added to the resulting A-1-1-a solution and stirred at 80°C for 3 hours. After stirring was completed, methanol (100 g) and 0.2 mol / L hydrochloric acid aqueous solution (3000 mL) were added and stirred for 30 minutes. Ethyl acetate (1570 g) was added and stirred until the precipitated solid dissolved, after which the organic layer was extracted. The extracted organic layer was washed with 0.2 mol / L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (1000 mL). The washed organic layer was reprecipitated in a 9 / 1 heptane / ethyl acetate mixed solution and then filtered. The resulting solid was reslurried and washed with a 9 / 1 heptane / ethyl acetate mixed solution, filtered, and vacuum dried to obtain 63 g of resin A-1-1.

[0294] 13 The composition ratio of the repeating units (mol % ratio; corresponding from left to right) measured by C-NMR was 34 / 8 / 58. The weight average molecular weight (Mw) was 5800 and the polydispersity (Mw / Mn) was 1.58.

[0295] [ka]

[0296] <Comparative Synthesis Example 1> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of a monomer represented by the following formula M'-1 (monomer (M'-1)) (51 g), a monomer represented by the following formula M-4 (monomer (M-4)) (7 g), a monomer represented by the following formula M-33 (monomer (M-33)) (42 g), cyclohexanone (186 g), and 2,2'-azobisisobutyric acid dimethyl ester (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) (5.9 g) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred at 85°C for an additional 2 hours to obtain an A'-1-1-a solution.

[0297] [ka]

[0298] To the resulting A'-1-1-a solution, methanol (80 g) and triethylamine (51 g) were added, and the mixture was stirred at 80°C for 3 hours in the same manner as in Synthesis Example 4 above. When the obtained product was checked, it was found that the deprotection reaction had not proceeded sufficiently (that is, the reaction described below had not proceeded sufficiently).

[0299] [ka]

[0300] <Comparative Synthesis Example 2> Cyclohexanone (45 g) was heated to 85°C under a nitrogen stream. While stirring this solution, a mixed solution of 52 g of a monomer represented by the following formula M'-2 (monomer (M'-2)), 14 g of a monomer represented by the following formula M'-3 (monomer (M'-3)), 34 g of a monomer represented by the following formula M-31 (monomer (M-31)), 170 g of cyclohexanone, and 5.6 g of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise over 6 hours to obtain a reaction solution. After the addition was completed, the reaction solution was stirred for an additional 2 hours at 85°C to obtain an A'-1-4-a solution.

[0301] [ka]

[0302] To the resulting A'-1-4-a solution, methanol (114 g) and triethylamine (72 g) were added, and the mixture was stirred at 80°C for 3 hours in the same manner as in Synthesis Example 7 above. When the obtained product was checked, it was found that the deprotection reaction had not proceeded sufficiently (that is, the reaction described below had not proceeded sufficiently).

[0303] [ka]

[0304] According to the present invention, a method for producing a resin having a phenolic hydroxyl group with good productivity can be provided. On the other hand, in the comparative synthesis example, some repeating units remained that could not be deprotected, and therefore it was not possible to obtain a resin containing repeating units having phenolic hydroxyl groups in the desired ratio.

Claims

1. A method for producing a resin containing a repeating unit (a0) having a phenolic hydroxyl group, comprising the steps of: (I) a step of polymerizing a group of monomers including a monomer (i) having a partial structure in which a phenolic hydroxyl group is protected with a structure represented by the following general formula (1) to obtain a polymer; (II) A step of solvolyzing the protecting moiety protected with the structure represented by the general formula (1) in the obtained polymer to obtain the phenolic hydroxyl group of the repeating unit (a0). A method for producing a resin, comprising the steps of: 【Chemistry 1】 In the general formula (1), X represents a halogen atom or an electron-withdrawing group. １ represents a hydroxy group or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4+2k). m represents an integer of 1 to (5+2k), provided that the relationship 1≦(n+m)≦(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R １ may be the same or different. When m is an integer of 2 or more, the multiple Xs may be the same or different. * indicates the bonding position of the phenolic hydroxyl group to the oxygen atom.

2. The method for producing a resin according to claim 1, wherein the monomer (i) is a monomer represented by the following general formula (2) or (3): 【Chemistry 2】 In general formula (2), Y １ represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, or a halogenated alkyl group. X represents a halogen atom or an electron-withdrawing group. R １ represents a hydroxy group or an organic group. ２ represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4+2k). m represents an integer of 1 to (5+2k), provided that the relationship 1≦(n+m)≦(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R １ may be the same or different. When m represents an integer of 2 or more, the multiple Xs may be the same or different. l represents an integer of 0 to 2. o2 represents an integer of 0 to (4+2l). p2 represents an integer of 1 to (5+2l), provided that the relationship 1≦(o2+p2)≦(5+2l) is satisfied. When o2 represents an integer of 2 or more, the multiple R ２ When p2 represents an integer of 2 or more, a plurality of X, R １ , k, m, and n may be the same or different. 【Transformation 3】 In the general formula (3), X represents a halogen atom or an electron-withdrawing group. １ represents a hydroxy group or an organic group. ３ represents a hydroxy group, a halogen atom, or an organic group. k represents an integer of 0 to 3. n represents an integer of 0 to (4+2k). m represents an integer of 1 to (5+2k), provided that the relationship 1≦(n+m)≦(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R １ may be the same or different. When m represents an integer of 2 or more, multiple Xs may be the same or different. o3 represents an integer of 0 to 5. p3 represents an integer of 1 to 6, provided that the relationship 1≦(o3+p3)≦6 is satisfied. When o3 represents an integer of 2 or more, multiple R ３ When p3 represents an integer of 2 or more, a plurality of X, R １ , k, m, and n may be the same or different.

3. The method for producing a resin according to claim 1 or 2, wherein X in the general formula (1), (2), or (3) represents a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C(=O)OR group (R represents a hydrocarbon group).

4. The method for producing a resin according to any one of claims 1 to 3, wherein the solvolysis in the step (II) is carried out in the presence of a basic compound.

5. The method for producing a resin according to claim 4 , wherein an amine compound is used as the basic compound.

6. (III) A method for producing a resin according to any one of claims 1 to 5, further comprising a step of contacting the polymer obtained after step (II) with an acidic aqueous solution.

7. (IV) mixing the solution containing the polymer after the step (II) with a poor solvent for the polymer.

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