JP2023121675A - Method for producing resin having phenolic hydroxyl group - Google Patents

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 The present invention relates to a method for producing a resin having phenolic hydroxyl groups.

Conventionally, in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs, microfabrication is performed by lithography using a photoresist composition. 2. Description of the Related Art In recent years, as integrated circuits have become more highly integrated, there has been a demand for ultra-fine pattern formation in the submicron region or quarter micron region. Along with this, there is a tendency for the exposure wavelength to become shorter, from the g-line to the i-line and then to the KrF excimer laser light. At present, an exposure machine using an ArF excimer laser with a wavelength of 193 nm as a light source has been developed. ing. Further, as a technique for further improving the resolution, the so-called liquid immersion method, in which the space between the projection lens and the sample is filled with a liquid with a high refractive index (hereinafter also referred to as "immersion liquid"), has been developed.

In addition to excimer laser light, lithography using electron beams (EB), X-rays, and extreme ultraviolet rays (EUV) is currently under development. Along with this, chemically amplified resist compositions and resins used therein have been developed which effectively respond to various radiations and are excellent in sensitivity and resolution.

Conventionally, resins having phenolic hydroxyl groups have been known as resins used in resist compositions, and methods for producing resins have also been investigated.

For example, Patent Document 1 discloses a method for producing a resin in which a group of monomers containing p-acetoxystyrene is polymerized, and then the acetyl-protected portion of p-acetoxystyrene is solvolyzed under basic conditions to obtain hydroxystyrene units. Are listed.
Further, in Patent Document 2, after polymerizing a monomer group containing p-(1-ethoxyethoxy)styrene, the acetal protecting portion of p-(1-ethoxyethoxy)styrene is solvolyzed under acidic conditions to give hydroxystyrene. A method of making the resin is described, which yields the units.

Japanese Unexamined Patent Application Publication No. 2012-219162 JP-A-2006-104347

However, the production method described in Patent Document 1 requires a long time for the solvolysis reaction, and cannot be said to be an industrially advantageous method. In addition, in the production method described in Patent Document 2, since the solvolysis reaction is performed under acidic conditions, the other raw material monomer species used in the production of the resin are limited to raw materials with high acid stability. There is sometimes a problem of corrosion of the reactor.

Accordingly, an object of the present invention is to provide a method for producing a resin having a phenolic hydroxyl group with good productivity. Specifically, it is an object of the present invention to provide a method for producing a resin having a phenolic hydroxyl group, which has a short reaction time, little restriction on resin raw materials, and can suppress corrosion of a reactor.

The inventors have found that the above problems can be solved by the following configuration.

[1]
A method for producing a resin containing a repeating unit (a0) having a phenolic hydroxyl group,
(I) a step of polymerizing a monomer group containing 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 high molecular weight product;
(II) The step of obtaining the phenolic hydroxyl group of the repeating unit (a0) by solvolyzing the protected portion protected by the structure represented by the general formula (1) in the obtained high molecular weight product. Methods of making resins, including in order.

In general formula (1), X represents a halogen atom or an electron-withdrawing group. R ₁ represents a hydroxy group or an organic group. k represents an integer of 0 to 3; n represents an integer from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. * represents the bonding position with the oxygen atom of the phenolic hydroxyl group.

[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).

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. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. l represents an integer of 0 to 2; o2 represents an integer from 0 to (4+2l). p2 represents an integer from 1 to (5+2l). However, the relationship 1≤(o2+p2)≤(5+2l) is satisfied. When o2 represents an integer of 2 or more, multiple _R2 may be the same or different. When p2 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different.

In general formula (3), X represents a halogen atom or an electron-withdrawing group. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. o3 represents an integer of 0 to 5; p3 represents an integer of 1-6. However, the relationship 1≤(o3+p3)≤6 is satisfied. When o3 represents an integer of 2 or more, multiple _R3 may be the same or different. When p3 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different.

[3]
X in the above general formula (1), (2), or (3) is a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C (= O) OR group (R represents a hydrocarbon group ), the method for producing a resin according to [1] or [2].
[4]
The method for producing a resin according to any one of [1] to [3], wherein the solvolysis in step (II) is performed 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.

[6]
(III) A method for producing a resin according to any one of [1] to [5], which comprises a step of contacting the high molecular weight material after step (II) above with an acidic aqueous solution.
[7]
(IV) The resin according to any one of [1] to [6], including a step of mixing the solution containing the high molecular weight after the step (II) with a poor solvent for the high molecular weight. Production method.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of resin which has a favorable productivity and which has a phenolic hydroxyl group can be provided.

The present invention will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
Regarding the notation of a group (atomic group) in the present specification, as long as it does not contradict the spirit of the present invention, the notation that does not describe substituted or unsubstituted includes groups containing substituents as well as groups that do not have substituents. do. For example, an "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In addition, the term "organic group" as used herein refers to a group containing at least one carbon atom.
As a substituent, a monovalent substituent is preferable unless otherwise specified.

As used herein, "actinic ray" or "radiation" means, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme Ultraviolet), X-rays, and electron beams (EB : Electron Beam).
As used herein, "light" means actinic rays or radiation.
In the present specification, the term "exposure" means, unless otherwise specified, not only exposure by the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, and X-rays, but also electron beams and ion beams. It also includes drawing with particle beams such as beams.
As used herein, the term "to" is used to include the numerical values before and after it as lower and upper limits.

In the present specification, the binding direction of the divalent linking groups described is not limited unless otherwise specified. For example, in the compound represented by the formula "XYZ", when Y is -COO-, Y may be -CO-O- or -O-CO- good too. The compound may be "X—CO—O—Z" or "X—O—CO—Z."

As used herein, (meth)acrylate refers to acrylate and methacrylate, and (meth)acryl refers to acrylic and methacrylic.
In the present specification, weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (hereinafter also referred to as "molecular weight distribution") (Mw/Mn) are measured by GPC (Gel Permeation Chromatography) equipment (Tosoh Corporation). GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40 ° C., flow rate: 1.0 mL / min, detector : Defined as a polystyrene conversion value by a differential refractive index detector (Refractive Index Detector).

[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)"),
(I) a step of polymerizing a monomer group containing a monomer (i) having a partial structure in which the phenolic hydroxyl group is protected by the structure represented by the general formula (1) to obtain a high molecular weight product;
(II) The step of obtaining the phenolic hydroxyl group of the repeating unit (a0) by solvolyzing the protected portion protected by the structure represented by the general formula (1) in the obtained high molecular weight product. Including in order.
In the production method of the present invention, a monomer (i) having a specific partial structure protected by the structure represented by the general formula (1) is used as a raw material monomer to increase the molecular weight. The protective structure in the high-molecular-weight polymer is preferable for industrial productivity because it can be deprotected in a short period of time under mild conditions. In addition, since an acidic compound is not required for the deprotection reaction, there is no need to limit other raw material monomer species used for copolymerization to those having high acid stability, and the degree of freedom in resin composition can be increased. Also, there is no problem of corrosion of the reactor during production.

[Step (I)]
In the production method of the present invention, as step (I), a monomer group containing 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) is polymerized. to obtain a high molecular weight substance.
In the following, first, the high-molecular-weight material (hereinafter also referred to as "resin (A)") obtained by the above step (I) will be described, and then the step (I) will be described.

<<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 by a structure represented by the following general formula (1). The repeating unit (a1) is a repeating unit that becomes a repeating unit (a0) having a phenolic hydroxyl group in the resin (A1) through step (II) described below.

In general formula (1), X represents a halogen atom or an electron-withdrawing group. R ₁ represents a hydroxy group or an organic group. k represents an integer of 0 to 3; n represents an integer from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. * represents the bonding position with the oxygen atom of the phenolic hydroxyl group.

In general formula (1), X represents a halogen atom or an electron-withdrawing group.
A halogen atom represented by X includes a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

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

X is preferably a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C(=O) OR group, a fluorine atom, a bromine atom, an iodine atom, a trifluoromethyl group, a nitro group, or A —C(=O)OCH ₃ group is more preferred, and a fluorine atom or an iodine atom is even more preferred.

In general formula (1), R ₁ represents a hydroxy group or an organic group.
Examples of organic groups represented by R ₁ include alkyl groups (linear or branched), alkoxy groups (linear or branched), alkenyl groups (linear or branched), cycloalkyl groups (single cyclic or polycyclic), aryl groups (monocyclic or polycyclic), and the like.

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

R ₁ is preferably a hydroxyl group, an alkyl group, an alkoxy group, or an aryl group, more preferably a hydroxyl group, a methyl group, a methoxy group, a phenyl group, or a trifluoromethylphenyl group.

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

In general formula (1), n represents an integer from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied.
n is preferably an integer of 0 to 2, more preferably 0.
m is preferably an integer of 1 to 3, more preferably 1 or 2.

(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).

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. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. l represents an integer of 0 to 2; o2 represents an integer from 0 to (4+2l). p2 represents an integer from 1 to (5+2l). However, the relationship 1≤(o2+p2)≤(5+2l) is satisfied. When o2 represents an integer of 2 or more, multiple _R2 may be the same or different. When p2 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different.

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

In general formula (2), _Y1 represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group, or a halogenated alkyl group.
A halogen atom represented by Y ₁ includes a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.
The alkyl group represented by Y ₁ includes linear or branched alkyl groups having 1 to 12 carbon atoms, preferably a methyl group or an ethyl group, more preferably a methyl group.
Examples of the halogenated alkyl group represented by Y ₁ include a group in which the above alkyl group such as a trifluoromethyl group is substituted with a halogen atom.

Y ₁ 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. , a hydrogen atom or a methyl group is more preferred, and a hydrogen atom is particularly preferred.

In general formula (2), _R2 represents a hydroxy group, a halogen atom, or an organic group.
Halogen atoms represented by R ₂ include fluorine, chlorine, bromine and iodine atoms.
Examples of the organic group represented by R ₂ include the organic groups represented by R ₁ described above.

In general formula (2), l represents an integer of 0 to 2, preferably 0 or 1.

In general formula (2), o2 represents an integer from 0 to (4+2l). p2 represents an integer from 1 to (5+2l). However, the relationship 1≤(o2+p2)≤(5+2l) is satisfied.
o2 is preferably 0 or 1, more preferably 0.
Preferably, p2 is 1 or 2.

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

In general formula (2-1), Y ₁ , X, R ₁ , R ₂ , l, o2, and p2 are Y ₁ , X, R ₁ , R ₂ , l, o2, and p2, and preferred examples are also the same.

In general formula (2-1), n2 represents an integer of 0-4. m2 represents an integer of 1 to 5; However, the relationship 1≤(n2+m2)≤5 is satisfied.
n2 is preferably an integer of 0 to 2, more preferably 0.
m2 is preferably an integer of 1 to 3, more preferably 1 or 2.

In general formula (2-2), Y ₁ , X, R ₁ , R ₂ , n2, m2, l, o2 and p2 are Y ₁ , X, R ₁ and R in general formula (2-1) ₂ , n2, m2, l, o2, and p2, and preferred examples are also the same.

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) .

In general formula (2-1A), Y ₁ , X, m2, l, and p2 are synonymous with Y ₁ , X, m2, l, and p2 in general formula (2-1), and preferred examples are also It is the same.

In general formula (2-2A), Y ₁ , X, m2, l, and p2 are synonymous with Y ₁ , X, m2, l, and p2 in general formula (2-2), and preferred examples are also It is the same.

In general formula (3), X represents a halogen atom or an electron-withdrawing group. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. o3 represents an integer of 0 to 5; p3 represents an integer of 1-6. However, the relationship 1≤(o3+p3)≤6 is satisfied. When o3 represents an integer of 2 or more, multiple _R3 may be the same or different. When p3 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different.

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

In general formula (3), _R3 represents a hydroxy group, a halogen atom, or an organic group.
A halogen atom represented by _R3 includes a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.
Examples of the organic group represented by R ₃ include the organic groups represented by R ₁ described above.

In general formula (3), o3 represents an integer of 0-5. p3 represents an integer of 1-6. However, the relationship 1≤(o3+p3)≤6 is satisfied.
o3 is preferably 0 or 1, more preferably 0.
p3 is preferably 1 or 2, more preferably 1.

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

In general formula (3-1), X, R ₁ , R ₃ , o3, and p3 are synonymous with X, R ₁ , R ₃ , o3, and p3 in general formula (3), and preferred examples are also It is the same.

In general formula (3-1), n3 represents an integer of 0-4. m3 represents an integer of 1 to 5; However, the relationship 1≤(n3+m3)≤5 is satisfied.
n3 is preferably an integer of 0 to 2, more preferably 0.
m3 is preferably an integer of 1 to 3, more preferably 1 or 2.

The monomer represented by general formula (3-1) above is more preferably a monomer represented by general formula (3-1A) below.

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

Specific examples of the monomer (i) are shown below, but are not limited thereto. In the specific examples below, Me represents a methyl group.

The content of the repeating unit (a1) is preferably 2 mol % or more, more preferably 5 mol % or more, still more preferably 10 mol % or more, relative to all repeating units in the resin (A). Moreover, 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 all repeating units in the resin (A).

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

As will be described later, the finally obtained resin (A1) can be suitably used in a resist composition. When the resin (A), that is, the resin (A1) has an acid-decomposable group, the pattern forming method using the resist composition containing the resin (A1) typically employs an alkaline developer as the developer. In this case, a positive pattern is preferably formed, and when an organic developer is used as the developer, a negative pattern is preferably formed.
As the repeating unit having an acid-decomposable group, a repeating unit having an acid-decomposable group containing an unsaturated bond is preferable in addition to the repeating unit having an acid-decomposable group described below.

(Repeating unit having an acid-decomposable group)
An acid-decomposable group is a group that is decomposed by the action of an acid to form a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected with a group that is released by the action of an acid (leaving group). That is, the resin (A) preferably has a repeating unit having a group that is decomposed by the action of an acid to form a polar group. A resin having this repeating unit has an increased polarity under the action of an acid, thereby increasing the solubility in an alkaline developer and decreasing the solubility in an organic solvent.
The polar group is preferably an alkali-soluble group such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphoric acid group, a sulfonamide group, a sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkylcarbonyl)imide group, bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl) Methylene groups, acidic groups such as tris(alkylsulfonyl)methylene groups, and alcoholic hydroxyl groups are included.
Among them, 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.

Examples of groups that leave by the action of an acid include groups represented by formulas (Y1) to (Y4).
Formula (Y1): -C(Rx ₁ )(Rx ₂ )(Rx ₃ )
Formula (Y2): -C(=O)OC(Rx ₁ )(Rx ₂ )(Rx ₃ )
Formula (Y3): —C(R ₃₆ )(R ₃₇ )(OR ₃₈ )
Formula (Y4): -C(Rn)(H)(Ar)

In formulas (Y1) and (Y2), Rx ₁ to Rx ₃ each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched chain) or an aryl group (monocyclic or polycyclic). When all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched), at least two of Rx ₁ to Rx ₃ are preferably methyl groups.
Among them, Rx ₁ to Rx ₃ preferably each independently represent a linear or branched alkyl group, and Rx ₁ to Rx ₃ each independently represent a linear alkyl group. is more preferred.
Two of Rx ₁ to Rx ₃ may combine to form a monocyclic or polycyclic ring.
The alkyl groups of Rx ₁ to Rx ₃ are alkyl groups having 1 to 5 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
The cycloalkyl groups represented by Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. is preferred.
The aryl group represented by Rx ₁ to Rx ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
A vinyl group is preferable as the alkenyl group for Rx ₁ to Rx ₃ .
The ring formed by combining two of Rx ₁ to Rx ₃ is preferably a cycloalkyl group. The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, and a tetracyclododeca. A polycyclic cycloalkyl group such as a nyl group or an adamantyl group is preferable, and a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
In the cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ , one of the methylene groups constituting the ring is a group containing a heteroatom such as an oxygen atom, a heteroatom such as a carbonyl group, or a vinylidene group. may be replaced with In these cycloalkyl groups, one or more 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, Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ combine to form the above-described cycloalkyl group. is preferred.
For example, when the resist composition is a resist composition for EUV exposure, two of alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, and Rx ₁ to Rx ₃ represented by Rx ₁ to Rx ₃ are bonded It is also preferred that the ring formed by further has a fluorine atom or an iodine atom as a substituent.

In formula (Y3), R ₃₆ to R ₃₈ each independently represent a hydrogen atom or a monovalent organic group. R ₃₇ and R ₃₈ may combine with each other to form a ring. Monovalent organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups. It is also preferred that R ₃₆ is a hydrogen atom.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain a heteroatom such as an oxygen atom and/or a group containing a heteroatom such as a carbonyl group. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more of the methylene groups may be replaced with a heteroatom such as an oxygen atom and/or a group containing a heteroatom such as a carbonyl group. good.
R ₃₈ may combine with another substituent of the main chain of the repeating unit to form a ring. The group formed by bonding R ₃₈ and another substituent of the main chain of the repeating unit to each other is preferably an alkylene group such as a methylene group.
When the resist composition is, for example, a resist composition for EUV exposure, the monovalent organic groups represented by R ₃₆ to R ₃₈ and the ring formed by combining R ₃₇ and R ₃₈ with each other are Furthermore, it is also preferable to have a fluorine atom or an iodine atom as a substituent.

As the formula (Y3), a group represented by the following formula (Y3-1) is preferable.

Here, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group combining these (e.g., a group combining an alkyl group and an aryl group). .
M represents a single bond or a divalent linking group.
Q is an alkyl group optionally containing a heteroatom, a cycloalkyl group optionally containing a heteroatom, an aryl group optionally containing 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).
In alkyl groups and cycloalkyl groups, for example, one of the methylene groups may be replaced by a heteroatom such as an oxygen atom or a heteroatom-containing group such as a carbonyl group.
One of L ₁ and L ₂ is preferably a hydrogen atom, and the other is preferably an alkyl group, a cycloalkyl group, an aryl group, or a combination of an alkylene group and an aryl group.
At least two of Q, M, and _L1 may combine to form a ring (preferably a 5- or 6-membered ring).
From the viewpoint of pattern refinement, _L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Secondary alkyl groups include isopropyl, cyclohexyl, and norbornyl groups, and tertiary alkyl groups include tert-butyl and adamantane groups. In these embodiments, the Tg (glass transition temperature) and the activation energy are increased, so that the film strength can be ensured and fogging can be suppressed.

When the resist composition is, for example, a resist composition for EUV exposure, the alkyl group, cycloalkyl group, aryl group, and a group combining these represented by L ₁ and L ₂ are further substituents It is also preferable to have a fluorine atom or an iodine atom as. The alkyl group, cycloalkyl group, aryl group, and aralkyl group preferably contain a heteroatom such as an oxygen atom in addition to the fluorine atom and the iodine atom. Specifically, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, for example, one of the methylene groups is replaced with a heteroatom such as an oxygen atom, or a group containing a heteroatom such as a carbonyl group. may be
For example, when the resist composition is a resist composition for EUV exposure, the alkyl group represented by Q which may contain a heteroatom, the cycloalkyl group which may contain a heteroatom, the heteroatom-containing aryl group, amino group, ammonium group, mercapto group, cyano group, aldehyde group, and groups in which these are combined, the heteroatom is selected from the group consisting of a fluorine atom, an iodine atom and an oxygen atom. A heteroatom is also preferred.

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 combine with each other to form a non-aromatic ring. Ar is preferably an aryl group.
For example, when the resist composition is a resist composition for EUV exposure, the aromatic ring group represented by Ar and the alkyl group, cycloalkyl group and aryl group represented by Rn have fluorine as a substituent. It is also preferred to have an atom or an iodine atom.

From the viewpoint of excellent acid decomposability of the repeating unit, when a non-aromatic ring is directly bonded to a polar group (or a residue thereof) in a leaving group that protects a polar group, in the non-aromatic ring, It is also preferable that the ring member atoms adjacent to the ring member atoms directly bonded to the polar group (or residue thereof) do not have halogen atoms such as fluorine atoms as substituents.

Groups that can be eliminated by the action of an acid also include a 2-cyclopentenyl group having a substituent (such as an alkyl group) such as a 3-methyl-2-cyclopentenyl group, and a 1,1,4,4 A cyclohexyl group having a substituent (such as an alkyl group) such as a -tetramethylcyclohexyl group may also be used.

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 general formulas (4) to (6) below.

In general formula (4), _Y4 represents a hydrogen atom, a fluorine atom, or an alkyl group. R ₄₁ , R ₄₂ and R ₄₃ each independently represent an organic group. Two of R ₄₁ , R ₄₂ and R ₄₃ may combine with each other to form a ring.

In 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. Although the number of carbon atoms in the alkyl group is not particularly limited, it is preferably 1-10, more preferably 1-3.
The alkyl group represented by Y ₄ may have a substituent, and examples of the substituent include a halogen atom (such as a fluorine atom), a hydroxyl group, and a monovalent organic group.
_Y4 is preferably a hydrogen atom or a methyl group.

In general formula (4), R ₄₁ , R ₄₂ and R ₄₃ each independently represent an organic group. Organic groups represented by R ₄₁ , R ₄₂ and R ₄₃ include alkyl groups (linear or branched), cycloalkyl groups (monocyclic or polycyclic) and alkenyl groups (linear or branched). , an aryl group (monocyclic or polycyclic), a heteroaryl group (monocyclic or polycyclic), and the like.

The alkyl group represented by R ₄₁ , R ₄₂ and R ₄₃ includes 1 to 1 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. 5 alkyl groups are preferred.
The cycloalkyl groups represented by R ₄₁ , R ₄₂ and R ₄₃ include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl, norbornyl, tetracyclodecanyl, tetracyclododecanyl, And polycyclic cycloalkyl groups such as adamantyl groups are preferred.
The aryl group represented by R ₄₁ , R ₄₂ and R ₄₃ is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group and a naphthyl group.
The heteroaryl group represented by R ₄₁ , R ₄₂ and R ₄₃ is preferably a heteroaryl group having 5 to 10 carbon atoms. mentioned.
A vinyl group is preferable as the alkenyl group represented by R ₄₁ , R ₄₂ and R ₄₃ .
A cycloalkyl group is preferable as the ring formed by combining two of R ₄₁ , R ₄₂ and R ₄₃ . The cycloalkyl group formed by combining two of R ₁₁ , R ₁₂ and R ₁₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, norbornyl group, tetracyclodeca A polycyclic cycloalkyl group such as a nyl group, a tetracyclododecanyl group or an adamantyl group is preferable, and a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
In the cycloalkyl group formed by combining two of R ₄₁ , R ₄₂ and R ₄₃ , one of the methylene groups constituting the ring contains a heteroatom such as an oxygen atom or a heteroatom such as a carbonyl group. may be substituted with a group or a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

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

In general formula (5), _Y5 represents a hydrogen atom, a fluorine atom, or an alkyl group. R ₅₁ , R ₅₂ and R ₅₃ each independently represent an organic group. Two of R ₅₁ , R ₅₂ and R ₅₃ may combine with each other to form a ring.

In general formula (5), _Y5 represents a hydrogen atom, a fluorine atom, or an alkyl group.
Examples of the alkyl group represented by Y ₅ include the alkyl group represented by Y ₄ , and preferable examples are the same.
_Y5 is preferably a hydrogen atom or a methyl group.

R ₅₁ , R ₅₂ and R ₅₃ in general formula (5) have the same meanings as R ₄₁ , R ₄₂ and R ₄₃ in general formula (4), and preferred examples are also the same.

In general formula (6), _Y6 represents a hydrogen atom, a fluorine atom, or an alkyl group. R ₆₁ , R ₆₂ and R ₆₃ each independently represent an organic group. Two of R ₆₁ , R ₆₂ and R ₆₃ may combine with each other to form a ring.

In general formula (6), _Y6 represents a hydrogen atom, a fluorine atom, or an alkyl group.
The alkyl group represented by _Y6 includes the alkyl group represented by _Y4 , and preferable examples are the same.
_Y6 is preferably a hydrogen atom or a methyl group.

R ₆₁ , R ₆₂ and R ₆₃ in general formula (6) have the same meanings as R ₄₁ , R ₄₂ and R ₄₃ in general formula (4), and preferred examples are also the same.

As the repeating unit having an acid-decomposable group, a repeating unit represented by formula (A) is also preferred.

L ₁ represents a divalent linking group optionally having a fluorine atom or an iodine atom, and R ₁ is a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group optionally having a fluorine atom or an iodine atom , or represents an aryl group optionally having a fluorine atom or an iodine atom, and R ₂ represents a leaving group optionally having a fluorine atom or an iodine atom which is eliminated by the action of an acid. However, at least one of L ₁ , R ₁ and R ₂ has a fluorine atom or an iodine atom.
The divalent linking group optionally having a fluorine atom or an iodine atom represented by L ₁ includes -CO-, -O-, -S-, -SO-, -SO ₂ -, fluorine atom or a hydrocarbon group optionally having an iodine atom (eg, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, etc.), and a linking group in which a plurality of these are linked. Among them, L ₁ is preferably -CO-, an arylene group, or an -arylene group - an alkylene group having a fluorine atom or an iodine atom -, and -CO- or an -arylene group - a fluorine atom or an iodine atom. An alkylene group with - is more preferred.
A phenylene group is preferred as the arylene group.
Alkylene groups may be linear or branched. Although the number of carbon atoms in the alkylene group is not particularly limited, it is preferably 1-10, more preferably 1-3.
The total number of fluorine atoms and iodine atoms contained in the alkylene group having fluorine atoms or iodine atoms is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

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

The leaving group optionally having a fluorine atom or an iodine atom represented by R ₂ is represented by the above formulas (Y1) to (Y4) and having a fluorine atom or an iodine atom. groups.

As the repeating unit having an acid-decomposable group, a repeating unit represented by formula (AI) is also preferred.

In formula (AI), Xa ₁ represents a hydrogen atom or an optionally substituted alkyl group. T represents a single bond or a divalent linking group. Rx ₁ to Rx ₃ each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), or an aryl ( monocyclic or polycyclic) group. However, when all of Rx ₁ to Rx ₃ are alkyl groups (linear or branched), at least two of Rx ₁ to Rx ₃ are preferably methyl groups.
Two of Rx ₁ to Rx ₃ may combine to form a monocyclic or polycyclic ring (such as a monocyclic or polycyclic cycloalkyl group).

Examples of the optionally substituted alkyl group represented by Xa ₁ include a methyl group and a group represented by -CH ₂ -R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Examples of the monovalent organic group represented by R ₁₁ 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, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. Xa ₁ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The divalent linking group for T includes an alkylene group, an aromatic ring group, a --COO--Rt-- group, and a --O--Rt-- group. In the formula, 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, a -CH ₂ - group, a -(CH ₂ ) ₂ - group, or a -(CH ₂ ) ₃ - groups are more preferred.

The alkyl groups of Rx ₁ to Rx ₃ include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
Cycloalkyl groups of Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group. is preferred.
The aryl group represented by Rx ₁ to Rx ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
A vinyl group is preferable as the alkenyl group for Rx ₁ to Rx ₃ .
The cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group. Polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group are also preferred. Among them, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred.
A cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring contains a heteroatom such as an oxygen atom, a heteroatom such as a carbonyl group, or It may be substituted with a vinylidene group. In these cycloalkyl groups, one or more ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.
In the repeating unit represented by formula (AI), for example, Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are preferably combined to form the above-mentioned cycloalkyl group.

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

The repeating unit represented by the formula (AI) includes an acid-decomposable (meth)acrylic acid tertiary alkyl ester-based repeating unit (Xa ₁ represents a hydrogen atom or a methyl group, and T represents a single bond. ) is preferred.

Specific examples of repeating units having an acid-decomposable group are shown below, but are not limited thereto. In the formula, Xa ₁ represents H, CH ₃ , CF ₃ or CH ₂ OH, and Rxa and Rxb each independently represent a linear or branched alkyl group having 1 to 5 carbon atoms. represents

Resin (A) may have a repeating unit having an acid-decomposable group containing an unsaturated bond as the repeating unit having an acid-decomposable group.
As the repeating unit having an acid-decomposable group containing an unsaturated bond, a repeating unit represented by formula (B) is preferable.

In formula (B), Xb represents a hydrogen atom, a halogen atom, or an optionally substituted alkyl group. L represents a single bond or a divalent linking group which may have a substituent. Ry ₁ to Ry ₃ 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 . However, at least one of Ry ₁ to Ry ₃ represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group.
Two of Ry ₁ to Ry ₃ may combine to form a monocyclic or polycyclic ring (a monocyclic or polycyclic cycloalkyl group, cycloalkenyl group, etc.).

The optionally substituted alkyl group represented by Xb includes, for example, a methyl group and a group represented by —CH ₂ —R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, for example, an alkyl 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, preferably an alkyl group having 3 or less carbon atoms, and more preferably a methyl group. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

The divalent linking group of L includes -Rt- group, -CO- group, -COO-Rt- group, -COO-Rt-CO- group, -Rt-CO- group, and -O-Rt- groups. In the formula, Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, preferably an aromatic ring group.
L is preferably -Rt-, -CO-, -COO-Rt-CO- or -Rt-CO-. Rt may have substituents such as halogen atoms, hydroxyl groups, and alkoxy groups.

The alkyl groups represented by Ry ₁ to Ry ₃ include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group. preferable.
Cycloalkyl groups represented by Ry ₁ to Ry ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group and adamantyl group. Polycyclic cycloalkyl groups are preferred.
The aryl group represented by Ry ₁ to Ry ₃ is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
A vinyl group is preferable as the alkenyl group for Ry ₁ to Ry ₃ .
An ethynyl group is preferred as the alkynyl group for Ry ₁ to Ry ₃ .
Cycloalkenyl groups represented by Ry ₁ to Ry ₃ are preferably monocyclic cycloalkyl groups such as cyclopentyl groups and cyclohexyl groups, which partially contain a double bond.
The cycloalkyl group formed by combining two of Ry ₁ to Ry ₃ includes a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, and a tetracyclododeca. Polycyclic cycloalkyl groups such as a nyl group and an adamantyl group are preferred. Among them, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferable.
A cycloalkyl group formed by combining two of Ry ₁ to Ry ₃ or a cycloalkenyl group, for example, one of the methylene groups constituting the ring is a hetero atom such as an oxygen atom, a carbonyl group, or —SO ₂ It may be substituted with a group containing a heteroatom such as a - group and a -SO ₃ - group, a vinylidene group, or a combination thereof. In these cycloalkyl groups or cycloalkenyl groups, one or more 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, Ry ₁ is a methyl group, an ethyl group, a vinyl group, an allyl group, or an aryl group, and Ry ₂ and Ry ₃ combine to form the above-mentioned cycloalkyl A preferred embodiment forms a group or a cycloalkenyl group.

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

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

The content of the repeating unit having an acid-decomposable group containing an unsaturated bond is preferably 15 mol% or more, more preferably 20 mol% or more, and 30 mol% or more, based on the total repeating units in the resin (A). is more preferred. Moreover, 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 all repeating units in the resin (A).

Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond are shown below, but are not limited thereto. In the formula, Xb and L ₁ represent any of the substituents and linking groups described above, Ar represents an aromatic group, and R represents 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''' having 1 to 20 carbon atoms an alkyl group or a fluorinated alkyl group), or a substituent such as a carboxyl group; Alternatively, a monocyclic or polycyclic aryl group is represented, and Q is a heteroatom such as an oxygen atom, a carbonyl group, a heteroatom-containing group such as a —SO ₂ — group and a —SO ₃ — group, a vinylidene group, or any of these represents a combination, and n, m and l represent integers of 0 or more.

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 further preferably 30 mol% or more, based on the total repeating units in the resin (A). preferable. The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, and particularly 60 mol% or less, relative to all repeating units in the resin (A). preferable.

<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 Group A below.
Group A: A group consisting of the following repeating units (20) to (25).
(20) a repeating unit having an acid group, which will be described later; (21) a repeating unit, which has neither an acid-decomposable group nor an acid group, and has a fluorine atom, a bromine atom, or an iodine atom, as described later; a repeating unit having a lactone group, a sultone group, or a carbonate group; (23) a repeating unit having a photoacid-generating group, which will be described later; (25) a repeating unit for reducing the mobility of the main chain The repeating units represented by formulas (A) to (E), which will be described later, are (25) reducing the mobility of the main chain corresponds to a repeating unit for

Resin (A) preferably has an acid group, and preferably contains a repeating unit having an acid group, as described later. The definition of the acid group will be explained later along with preferred embodiments of repeating units having an acid group. When the resin (A), that is, 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 resin (A1) and the photoacid generator Interactivity with the generated acid is more excellent. As a result, diffusion of acid is further suppressed, and the cross-sectional shape of the formed pattern can be made more rectangular.

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

(Repeating unit having an acid group)
Resin (A) may have a repeating unit having an acid group.
As the acid group, an acid group having a pKa of 13 or less is preferable. The acid dissociation constant of the acid group is preferably 13 or less, more preferably 3-13, even more preferably 5-10.
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 them, 0.8 to 6.0 mmol/g is preferable, 1.2 to 5.0 mmol/g is more preferable, and 1.6 to 4.0 mmol/g is even more preferable. If the content of the acid group is within the above range, the development proceeds satisfactorily, the formed pattern shape is excellent, and the resolution is also excellent.
The acid group is preferably, for example, a carboxyl group, a fluoroalcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group.
In the hexafluoroisopropanol group, one or more (preferably 1 to 2) fluorine atoms may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group).
Also preferred as the acid group is -C(CF ₃ )(OH)-CF ₂ - thus formed. Also, one or more of the fluorine atoms may be substituted with a group other than a fluorine atom to form a ring containing -C(CF ₃ )(OH)-CF ₂ -.
The repeating unit having an acid group is different from the repeating unit having a structure in which the polar group is protected by a group that leaves under the action of an acid, and the repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later. It is preferably a repeating unit.
A repeating unit having an acid group may have a fluorine atom or an iodine atom.

Repeating units having an acid group include the following repeating units.

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

(Repeating unit having neither an acid-decomposable group nor an acid group and having a fluorine atom, a bromine atom, or an iodine atom)
In the resin (A), apart from the above <repeating unit (a1) derived from monomer (i)><repeating unit (a2) having an acid-decomposable group> and <repeating unit having an acid group>, It may have a repeating unit having neither an acid-decomposable group nor an acid group and 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 and having a fluorine atom, a bromine atom, or an iodine atom> referred to here is a <repeating unit having a lactone group, a sultone group, or a carbonate group> described later. , and <repeating unit having photoacid-generating group>.

As unit X, a repeating unit represented by formula (C) is preferable.

_L5 represents a single bond or an ester group. _R9 represents a hydrogen atom or an alkyl group optionally having a fluorine atom or an iodine atom. R ₁₀ may have a hydrogen atom, an alkyl group optionally having a fluorine atom or an iodine atom, a cycloalkyl group optionally having a fluorine atom or an iodine atom, a fluorine atom or an iodine atom represents an aryl group or a group combining these;

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

The content of the unit X is preferably 0 mol % or more, more preferably 5 mol % or more, still more preferably 10 mol % or more, relative to all repeating units in the resin (A). Moreover, the upper limit thereof is preferably 50 mol % or less, more preferably 45 mol % or less, and still more preferably 40 mol % or less, relative to all repeating units in the resin (A).

Among the repeating units of the resin (A), the total content of repeating units containing at least one of a fluorine atom, a bromine atom and an iodine atom is preferably 10 mol% or more with respect to all repeating units of the resin (A). , more preferably 20 mol % or more, still more preferably 30 mol % or more, and particularly preferably 40 mol % or more. Although the upper limit is not particularly limited, it is, for example, 100 mol % or less with respect to all repeating units of the resin (A).
The repeating unit containing at least one of a fluorine atom, a bromine atom and an iodine atom includes, for example, a repeating unit having a fluorine atom, a bromine atom or an iodine atom and having an acid-decomposable group, a fluorine atom, a bromine repeating units having an acid group, and repeating units having a fluorine atom, a bromine atom, or an iodine atom.

(Repeating unit having a lactone group, a sultone group, or a carbonate group)
Resin (A) may have a repeating unit (hereinafter also referred to as “unit Y”) having at least one selected from the group consisting of a lactone group, a sultone group and a carbonate group.
It is also preferable that the unit Y does not have a hydroxyl group and an acid group such as a hexafluoropropanol group.

The lactone group or sultone group may have a lactone structure or sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered ring lactone structure or a 5- to 7-membered ring sultone structure. Among them, a 5- to 7-membered ring lactone structure in which a bicyclo structure or spiro structure is formed and another ring structure is condensed with another ring structure, or a 5- to 7-membered ring sultone in a form to form a bicyclo structure or spiro structure. More preferably, the structure is condensed with another ring structure.
The resin (A) has a lactone structure represented by any one of the following formulas (LC1-1) to (LC1-21), or any one of the following formulas (SL1-1) to (SL1-3). It preferably has a repeating unit having a lactone group or a sultone group obtained by removing one or more hydrogen atoms from a ring member atom of a sultone structure, and the lactone group or sultone group may be directly bonded to the main chain. For example, ring member atoms of a lactone group or a sultone group may constitute the main chain of resin (A).

The lactone structure or sultone structure may have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, and carboxyl groups. , halogen atoms, cyano groups, and acid-labile groups. n2 represents an integer of 0-4. When n2 is 2 or more, multiple Rb ₂ may be different, and multiple Rb ₂ may combine to form a ring.

Repeat 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) Examples of units include repeating units represented by the following formula (AI).

In formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.
A halogen atom for Rb ₀ includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Rb ₀ is preferably a hydrogen atom or a methyl group.
Ab is 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 combination of these divalent linkages represents a group. Among them, Ab is preferably a single bond or a linking group represented by -Ab ₁ -CO ₂ -. Ab ₁ is a linear or branched alkylene group or a monocyclic or polycyclic cycloalkylene group, preferably a methylene group, ethylene group, cyclohexylene group, adamantylene group or norbornylene group.
V is a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any one of formulas (LC1-1) to (LC1-21), or formulas (SL1-1) to (SL1- 3) represents a group obtained by removing one hydrogen atom from a ring member atom of the sultone structure represented by any one of 3).

When optical isomers are present in repeating units having a lactone group or a sultone group, any optical isomers may be used. Moreover, one optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

As the carbonate group, a cyclic carbonate group is preferred.
As the repeating unit having a cyclic carbonate group, a repeating unit represented by the following formula (A-1) is preferable.

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 ² represents a substituent. When n is 2 or more, a plurality of R _A ² may be the same or different. A represents a single bond or a divalent linking group. The divalent linking group includes 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 combination of these. A valent linking group is preferred. Z represents an atomic group forming a monocyclic or polycyclic ring together with the group represented by -O-CO-O- in the formula.

The unit Y is exemplified below. In the formula, Rx represents a hydrogen atom, -CH ₃ , -CH ₂ OH or -CF ₃ .

The content of the unit Y is preferably 1 mol % or more, more preferably 10 mol % or more, relative to all repeating units in the resin (A). The upper limit is preferably 85 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, and particularly 60 mol% or less, relative to all repeating units in the resin (A). preferable.

(Repeating unit having a photoacid-generating group)
The resin (A) may have, as a repeating unit other than the above, a repeating unit having a group that generates an acid upon exposure to actinic rays or radiation (hereinafter also referred to as a "photoacid-generating group").
Repeating units having a photoacid-generating group include repeating units represented by formula (4).

^R41 represents a hydrogen atom or a methyl group. ^L41 represents a single bond or a divalent linking group. ^L42 represents a divalent linking group. ^R40 represents a structural site that is decomposed by exposure to actinic rays or radiation to generate an acid in the side chain.
Examples of repeating units having a photoacid-generating group are shown below.

In addition, the repeating unit represented by formula (4) includes, for example, repeating units described in paragraphs [0094] to [0105] of JP-A-2014-041327, and International Publication No. 2018/193954. Examples include repeating units described in paragraph [0094].

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

(Repeating unit represented by formula (V-1) or formula (V-2) below)
Resin (A) may have a repeating unit represented by the following formula (V-1) or the following formula (V-2).
Repeating units represented by the following formulas (V-1) and (V-2) below are preferably different repeating units from the repeating units described above.

During the ceremony,
R ₆ and R ₇ 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 the number of carbon atoms; 1 to 6 alkyl groups or fluorinated alkyl groups), 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 0-6.
_n4 represents an integer of 0-4.
_X4 is a methylene group, an oxygen atom, or a sulfur atom.
The repeating units represented by formula (V-1) or (V-2) are exemplified below.
Examples of the repeating unit represented by formula (V-1) or (V-2) include repeating units described in paragraph [0100] of WO 2018/193954.

(Repeating unit for reducing the mobility of the main chain)
The resin (A) and the finally obtained resin (A1) preferably have a high glass transition temperature (Tg) from the viewpoint of suppressing excessive diffusion of generated acid or pattern collapse during development. Tg is preferably greater than 90°C, more preferably greater than 100°C, even more preferably greater than 110°C, and particularly preferably greater than 125°C. The Tg is preferably 400° C. or less, more preferably 350° C. or less, from the viewpoint of excellent dissolution rate in the developer.
In the present specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter "Tg of repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting only of each repeating unit contained in the polymer is calculated by the Bicerano method. Next, the mass ratio (%) of each repeating unit to all repeating units in the polymer is calculated. Next, the Fox formula (described in Materials Letters 62 (2008) 3152, etc.) is used to calculate the Tg at each mass ratio, and these are totaled 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 a polymer physical property estimation software MDL Polymer (MDL Information Systems, Inc.).

In order to increase the Tg of the resin (A) (preferably to make the Tg higher than 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 substituents that induce interaction between the resin (A) into the vicinity of the main chain ( d) Main Chain Formation in Cyclic Structure (e) Linking of Cyclic Structure to Main Chain The resin (A) preferably has a repeating unit exhibiting a homopolymer Tg of 130° C. or higher.
The type of repeating unit exhibiting a homopolymer Tg of 130° C. or higher is not particularly limited as long as it is a repeating unit having 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 the formulas (A) to (E) described below, the homopolymers correspond to repeating units exhibiting a homopolymer Tg of 130° C. or higher.

A specific example of means for achieving the above (a) is a method of introducing a repeating unit represented by the formula (A) into the resin (A).

Formula (A), _RA represents a group containing a polycyclic structure. R _x represents a hydrogen atom, a methyl group, or an ethyl group. A group containing a polycyclic structure is a group containing multiple ring structures, and the multiple 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 WO2018/193954.

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

In formula (B), R _b1 to R _b4 each independently represent a hydrogen atom or an organic group, and at least two or more of R _b1 to R _b4 represent an organic group.
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 type of other organic group is not particularly limited.
Further, when none of the organic groups is a group in which the ring structure is directly linked to the main chain in the repeating unit, at least two of the organic groups have three or more constituent atoms excluding hydrogen atoms. is a substituent.
Specific examples of the repeating unit represented by formula (B) include those described in paragraphs [0113] to [0115] of WO2018/193954.

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

In formula (C), R _c1 to R _c4 each independently represent a hydrogen atom or an organic group, and at least one of R _c1 to R _c4 is hydrogen bonding hydrogen within 3 atoms from the main chain carbon It is a group containing atoms. Above all, it is preferable to have a hydrogen-bonding hydrogen atom within 2 atoms (closer to the main chain side) in order to induce interaction between the main chains of the resin (A).
Specific examples of the repeating unit represented by formula (C) include those described in paragraphs [0119] to [0121] of WO2018/193954.

A specific example of means for achieving the above (d) is a method of introducing a repeating unit represented by the formula (D) into the resin (A).

In formula (D), "Cyclic" represents a group forming a main chain with a cyclic structure. The number of constituent atoms of 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 WO2018/193954.

A specific example of means for achieving (e) above is a method of introducing a repeating unit represented by the formula (E) into the resin (A).

In formula (E), each Re independently represents a hydrogen atom or an organic group. Examples of organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups, which may have substituents.
A "Cyclic" is a cyclic group containing carbon atoms in the main chain. The number of atoms contained in the cyclic group is not particularly limited.
Specific examples of the repeating unit represented by formula (E) include those described in paragraphs [0131] to [0133] of WO2018/193954.

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

The weight average molecular weight of the resin (A) is preferably 30,000 or less, more preferably 1,000 to 30,000, still more preferably 3,000 to 30,000, further preferably 5,000 as a polystyrene equivalent value by GPC method. ~15,000 is particularly preferred.
The dispersity (molecular weight distribution) of the resin (A) is preferably 1 to 5, more preferably 1 to 3, still more preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. The smaller the degree of dispersion, the better the resolution and resist shape, the smoother the side walls of the resist pattern, and the better the roughness.

<Polymerization method>
In step (I), a monomer group containing the above monomer (i) is polymerized to obtain a high molecular weight material (resin (A)).
The method for polymerizing the resin (A) is not particularly limited, and known methods can be used, such as radical polymerization. The radical polymerization method includes a batch polymerization method in which a monomer species, an initiator, etc. are dissolved in a solvent and then polymerized by heating, and a solution of a monomer species and an initiator in a heated solvent over 1 to 10 hours. A dropping polymerization method, which is added dropwise, is exemplified, and the dropping polymerization method is preferred.

As the monomer species, the above-mentioned monomer (i) is essential, and if necessary, a monomer represented by any one of the above general formulas (4) to (6), etc., repeating units (a2) and (a3) may be used. In addition, the ratio of each monomer to be used should be adjusted so that the repeating unit derived from each monomer obtained by polymerization falls within the preferred content ratio range of each repeating unit in the resin (A) described above. Just do it.

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; dimethylformamide and dimethylacetamide. amides such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, methanol, ethyl lactate, and cyclohexanone;
Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ -Butyrolactone, methanol, ethyl lactate, cyclohexanone and the like are preferred.

The polymerization reaction is preferably carried out under an inert gas atmosphere such as nitrogen and/or argon. As the polymerization initiator, commercially available radical initiators (azo initiators, peroxides, etc.) can be used. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is more preferable. Specific examples of polymerization initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, and dimethyl 2,2'-azobis(2-methylpropionate). If desired, a polymerization initiator is added additionally or dividedly, and after completion of the reaction, the resin (A) is recovered. The concentration of the reactants is preferably 5-50% by mass, more preferably 10-30% by mass. The reaction temperature is not particularly limited, and is generally preferably 10 to 150°C, more preferably 30 to 120°C, even more preferably 60 to 100°C.

Purification methods include liquid extraction to remove residual monomers and/or oligomers by washing with water and/or a combination of appropriate solvents; solution such as ultrafiltration to extract and remove compounds with a specific molecular weight or less. 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 to remove residual monomers, etc.; A resin precursor slurry that has been filtered A purification method in a solid state such as washing with a poor solvent; The solution containing the resin (A) may be directly used in the step (II) without performing the purification operation.

[Step (II)]
In the production method of the present invention, as step (II), the structure represented by the above general formula (1) which the repeating unit (a1) in the high molecular weight body (resin (A)) obtained in step (I) has and a step of obtaining a repeating unit (a0) having a phenolic hydroxyl group by solvolyzing the protecting moiety protected with. Solvolysis refers to the decomposition of a solute upon reaction with a solvent.

<Solvent>
As the solvent used in the solvolysis, a protic solvent is preferably used. Examples of protic solvents include monohydric or polyhydric alcohols, water and the like.

Examples of monohydric alcohols 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; 1-methoxy -2-propanol and the like.
Examples of polyhydric alcohols include ethylene glycol and propylene glycol.

Moreover, the solvent used in the solvolysis may be a mixed solvent of the protic solvent described above and another organic solvent.

Solvents used in solvolysis include alcohols such as methanol, 1-methoxy-2-propanol, and propylene glycol monomethyl ether, or mixed solvents of alcohols and other solvents, from the viewpoint of reactivity and solubility. preferable.

<Basic compound>
The solvolysis is preferably carried out in the presence of a basic compound. Examples of basic compounds include amine compounds, alkali metal hydroxides, alkali metal alkoxides, alkali metal carbonates, and the like.

Amine compounds include triethylamine, trimethylamine, tributylamine, t-butylamine, diisopropylethylamine, pyridine, N-methylpiperazine, 4-dimethylaminopyridine, 3-diethylaminopropylamine, pyrrole, 1,2-diaminopropane, piperidine. , trioctylamine, 2-ethylhexylamine, dibenzylamine, diazabicycloundecene, ammonia and the like.

Alkali metal hydroxides include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like.
Alkali metal alkoxides include sodium methoxide and the like.
Alkali metal carbonates include sodium carbonate and cesium carbonate.

The basic compound is preferably an amine compound, more preferably triethylamine, 4-dimethylaminopyridine, or diazabicycloundecene from the viewpoint of reactivity and easiness of purification in the post-process.

<Solvolysis reaction>
Solvolysis is carried out by, for example, adding the above protic solvent and a basic compound to the solution containing the high molecular weight material (resin (A)) obtained in step (I) above, and stirring and mixing. be able to.

The amount of the protic solvent to be added is preferably 5 equivalents or more with respect to 1 equivalent of the protective group.
When the basic compound is added, it is preferably added in an amount of 1 equivalent or more with respect to 1 equivalent of the protective group.

The reaction temperature for the solvolysis reaction is usually in the range of 0°C to 150°C, preferably in the range of 20°C to 90°C. The reaction temperature may be appropriately adjusted according to 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 1 to 4 hours.

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 period of time.
In addition, since an acidic compound is not required for the deprotection reaction, there is no need to limit other raw material monomer species used for copolymerization to those having high acid stability, and the degree of freedom in resin composition can be increased. Also, there is no problem of corrosion of the reactor during production.

[Step (III)]
A resin (A1) containing a repeating unit (a0) having a phenolic hydroxyl group is obtained by the above steps (I) and (II). It is preferable to have a step of contacting the high molecular weight material of with an acidic aqueous solution.
By bringing the high molecular weight substance into contact with the acidic aqueous solution, it is possible to remove highly water-soluble impurities in the solution containing the high molecular weight substance after step (II). Further, when a basic compound is used in step (II), the phenolic hydroxyl group in the high molecular weight compound is in a counter salt state with the basic compound (-O ^- M ⁺ ; M ⁺ is derived from the basic compound cation), which can be further converted into —OH groups.

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

The amount of the acidic aqueous solution to be added should only contain an acid that can convert the counter salt to an —OH group, and 1 equivalent or more of acid is included relative to 1 equivalent of the basic compound used. is preferred.

The contact with the acidic aqueous solution can be carried out, for example, by adding the acidic aqueous solution to the solution containing the high molecular weight substance after the step (II), and stirring and mixing. If necessary, a solvent may be added in addition to the acidic aqueous solution. Solvents include, for example, the protic solvents described above.

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 to obtain a solution containing the desired resin (A1). .

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

[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.

As the solution containing the polymer after step (II) is completed, the solution after step (III) is preferably used. That is, step (IV) is preferably performed after step (III).

As the poor solvent, depending on the type of polymer used, for example, hydrocarbon solvents, ethers, esters, alcohols, ketones, water and the like can be used. The poor solvent may be used singly or in combination of two or more. Moreover, a mixed solvent with other solvents other than the above may be used.

A solid resin (A1) can be obtained by filtering the reprecipitated resin (A1). The resin (A1) may be further subjected to ordinary purification treatment, for example, it may be washed with the above poor solvent to further remove impurities.

<<Resin (A1)>>
By the production method of the present invention described above, the resin (A1) containing the repeating unit (a0) having a phenolic hydroxyl group can be produced with good productivity. The preferred ranges of the weight-average molecular weight and the dispersity of the obtained resin (A1) are the same as the preferred ranges of the weight-average molecular weight and the dispersity of the resin (A) described above. In addition, the preferable content of the repeating unit (a0), the repeating unit (a2), and various repeating units (a3) with respect to all repeating units in the resin (A1) is , repeating unit (a1), repeating unit (a2), and various repeating units (a3).

[Actinic ray-sensitive or radiation-sensitive resin composition]
The resin (A1) obtained by the production method of the present invention can be suitably used for actinic ray-sensitive or radiation-sensitive resin compositions. 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.

In addition to the resin (A1), the resist composition contains various components such as a photoacid generator, an acid diffusion controller, a hydrophobic resin, a surfactant, a solvent, and other additives that can be used in ordinary resist compositions. sell.

<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 in the form of being incorporated into a part of a polymer (for example, resin (A1) described above). Moreover, the form of a low-molecular-weight compound and the form of being incorporated into a part of a polymer (for example, resin (A1) described above) may be used in combination.
In this specification, the photoacid generator (B) is preferably in the form of a low molecular weight compound.

Examples of the photoacid generator (B) include compounds (onium salts) represented by “M ⁺ X ⁻ ”, and compounds that generate an organic acid upon exposure are preferred.
Examples of the organic acid include sulfonic acid (aliphatic sulfonic acid, aromatic sulfonic acid, camphorsulfonic acid, etc.), carboxylic acid (aliphatic carboxylic acid, aromatic carboxylic acid, aralkylcarboxylic acid, etc.), carbonylsulfonylimide, acids, bis(alkylsulfonyl)imidic acids, and tris(alkylsulfonyl)methide acids.

In the compound represented by "M ⁺ X ^- ", M ⁺ represents an organic cation.
There are no particular restrictions on the organic cation. The valence of the organic cation may be 1 or 2 or more.

In the compound represented by “M ⁺ X ⁻ ”, X ⁻ represents an organic anion.
The organic anion is not particularly limited, and includes organic anions having a valence of 1, 2 or more.
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.

The photoacid generator is not particularly limited, and known photoacid generators can be used. (Corresponding US Patent Application Publication No. 2015/004533, paragraph 0339), JP 2019-045864, paragraphs 0144 to 0173, and the like.

<Acid diffusion control agent (C)>
The resist composition may contain an acid diffusion control agent.
The acid diffusion control agent traps the acid generated from the photoacid generator or the like during exposure, and acts as a quencher that suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid.
The type of acid diffusion controller is not particularly limited, and examples include basic compounds (CA), low-molecular-weight compounds (CB) having nitrogen atoms and groups that leave under the action of acids, and actinic rays or radiation. and a compound (CC) whose ability to control acid diffusion decreases or disappears upon irradiation.
As the compound (CC), an onium salt compound (CD), which becomes a relatively weak acid with respect to the photoacid generator, and a basic compound (CE), whose basicity is reduced or lost by irradiation with actinic rays or radiation. mentioned.
Specific examples of the basic compound (CA) include, for example, those described in paragraphs [0132] to [0136] of WO2020/066824, and the basicity is reduced or reduced by exposure to actinic rays or radiation. Specific examples of the disappearing basic compound (CE) include those described in paragraphs [0137] to [0155] of WO 2020/066824, and paragraph [0164] of WO 2020/066824. Specific examples of the low-molecular compound (CB) having a nitrogen atom and a group that leaves under the action of an acid include paragraphs [0156] to [0163] of International Publication No. 2020/066824. ] include those described in .
Specific examples of the onium salt compound (CD), which is a relatively weak acid with respect to the photoacid generator, include those described in paragraphs [0305] to [0314] of International Publication No. 2020/158337. .

In addition to the above, for example, paragraphs [0627] to [0664] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0095] to [0187] of US Patent Application Publication No. 2015/0004544A1, US Patent Application Publication No. 2016/0237190A1 and paragraphs [0259] to [0328] of US Patent Application Publication No. 2016/0274458A1 can be suitably used as acid diffusion control agents.

<Hydrophobic resin (D)>
The resist composition may further contain a hydrophobic resin different from the resin (A1).
From the viewpoint of uneven distribution on 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 the side chain portion of the resin. It is more preferable to have The hydrophobic resin preferably has a hydrocarbon group with 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on the side chain.
Hydrophobic resins include compounds described in paragraphs [0275] to [0279] of WO2020/004306.

<Surfactant (E)>
The resist composition may contain a surfactant. When a surfactant is contained, it is possible to form a pattern with excellent adhesion and fewer development defects.
The surfactant is preferably a fluorine-based and/or silicon-based surfactant.
Fluorinated and/or silicon-based surfactants include surfactants disclosed in paragraphs [0218] and [0219] of WO2018/193954.

<Solvent (F)>
The resist composition preferably contains a solvent.
Solvent consists of (M1) propylene glycol monoalkyl ether carboxylate and (M2) propylene glycol monoalkyl ether, lactate, acetate, alkoxypropionate, linear ketone, cyclic ketone, lactone, and alkylene carbonate. It is preferable to include at least one selected from the group. The solvent may further contain components other than components (M1) and (M2).
Details of component (M1) and component (M2) are described in paragraphs [0218] to [0226] of WO2020/004306, the contents of which are incorporated herein.

<Other additives>
The resist composition contains 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 a carboxyl group alicyclic or aliphatic compounds containing) may further be included.

A resist composition containing the resin (A1) of the present specification is suitably used as a photosensitive composition for EB exposure and a photosensitive composition for EUV exposure.

The present invention will be described in more detail based on examples below. Materials, usage amounts, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the examples shown below.

<Synthesis Example 1: Synthesis of Monomer M-80>

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). After cooling the reaction solution in an ice bath, 3,5-bis(trifluoromethyl)benzoyl chloride (26.6 g) was added. After the mixture was stirred at room temperature (25° C.) for 2 hours, water (100 g) was added, and the solvent was evaporated from the organic layer to obtain M-80-b (35.7 g, yield 99%). got

M-80-b (10.0 g) and N-bromosuccinimide (NBS) (11.7 g) were dissolved in ethyl acetate (AcOEt) (80.0 g). After the mixture was stirred at 80° C. for 2 hours, it was diluted with ethyl acetate (200 mL) and washed with saturated aqueous sodium hydrogencarbonate solution (150 mL) and distilled water (150 mL). By evaporating the solvent from the organic layer, M-80-c (17.4 g) was obtained (yield 99%).

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%).

¹ H-NMR measurement results of the monomer (M-80) are shown below.
¹ H-NMR (CDCl ₃ ): 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)

<Synthesis Example 2: Synthesis of Monomer M-81>

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). After cooling the reaction solution in an ice bath, 4-nitrobenzoyl chloride (17.2 g) was added. After the mixture was stirred at room temperature (25° C.) for 2 hours, water (100 g) was added, and the solvent was evaporated from the organic layer to obtain M-81-b (27.8 g, yield 99%). got

M-81-b (10.0 g) and N-bromosuccinimide (NBS) (11.7 g) were dissolved in ethyl acetate (AcOEt) (80.0 g). After the mixture was stirred at 80° C. for 2 hours, it was diluted with ethyl acetate (200 mL) and washed with saturated aqueous sodium hydrogencarbonate solution (150 mL) and distilled water (150 mL). By evaporating the solvent from the organic layer, M-81-c (14.6 g) was obtained (yield 99%).

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%).

The measurement results of ¹ H-NMR of the monomer (M-81) are shown below.
¹ H-NMR (CDCl ₃ ): 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)

<Synthesis Example 3: Synthesis of Monomer M-89>

4-acetoxystyrene (500 g) was dissolved in ethyl acetate (929 g). After cooling the reaction solution to −15° C., a 28 wt % methanol solution (238 g) of sodium methoxide was added. After stirring at 5° C. or lower for 1 hour, 1 mol/L hydrochloric acid aqueous solution (800 mL) was added to extract the organic layer. The organic layer was washed twice with a 1 mol/L hydrochloric acid aqueous solution (500 mL) and then washed five times with distilled water (500 mL). By concentrating the organic layer, 730 g of a 50 wt % ethyl acetate solution of 4-hydroxystyrene was obtained (yield 99%).

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). . After cooling the reaction solution in an ice bath, 3,5-bis(trifluoromethyl)benzoyl chloride (72.5 g) was added. After the mixture was stirred at room temperature (25° C.) for 2 hours, water (100 g) was added, the solvent was distilled off from the organic layer, and column purification (developing solvent: hexane/ethyl acetate) was performed. M-89 (70 g, 78% yield) was obtained.

¹ H-NMR measurement results of the monomer (M-89) are shown below.
¹ H-NMR (CDCl ₃ ): 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)

<Synthesis Example 4: Synthesis of Resin A-1-1>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, a monomer represented by the following formula M-80 (monomer (M-80)) (51 g) and 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 dimethyl 2,2′-azobisisobutyrate [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 dropwise addition was completed, the reaction solution was stirred at 85° C. for an additional 2 hours to obtain an A-1-1-a solution.

Methanol (80 g) and triethylamine (61 g) were added to the obtained A-1-1-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1 (mass ratio) (hereinafter, the ratio in the mixed solution is the mass ratio unless otherwise specified), and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 63 g of Resin A-1-1.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR (nuclear magnetic resonance) was 34/8/58. Also, the weight average molecular weight (Mw) was 5800 and the degree of dispersion (Mw/Mn) was 1.58. The weight average molecular weight (Mw) and the degree of dispersion (Mw/Mn) were measured by GPC (carrier: tetrahydrofuran (THF)) (in terms of polystyrene).

<Synthesis Example 5: Synthesis of Resin A-1-2>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, a monomer represented by the following formula M-89 (monomer (M-89)) (56 g) and a monomer represented by the following formula M-4 (monomer (M-4)) (13 g) , a monomer represented by the following formula M-31 (monomer (M-31)) (31 g), cyclohexanone (192 g), and dimethyl 2,2'-azobisisobutyrate [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 dropwise addition was completed, the reaction solution was stirred at 85° C. for another 2 hours to obtain an A-1-2-a solution.

Methanol (100 g) and triethylamine (63 g) were added to the obtained A-1-2-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 54 g of Resin A-1-2.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 40/13/47. Also, the weight average molecular weight (Mw) was 6500, and the degree of dispersion (Mw/Mn) was 1.60.

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

Methanol (65 g) and triethylamine (41 g) were added to the obtained A-1-3-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 54 g of Resin A-1-3.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 22/12/66. Also, the weight average molecular weight (Mw) was 7100 and the degree of dispersion (Mw/Mn) was 1.60.

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

Methanol (114 g) and triethylamine (72 g) were added to the obtained A-1-4-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid dissolved, and then 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 50 g of resin A-1-4.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 38/9/53. Also, the weight average molecular weight (Mw) was 6800, and the degree of dispersion (Mw/Mn) was 1.56.

<Synthesis Example 8: Synthesis of Resin A-1-1B>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, a monomer represented by the following formula M-80 (monomer (M-80)) (51 g) and 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 dimethyl 2,2′-azobisisobutyrate [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 dropwise addition was completed, the reaction solution was stirred at 85° C. for an additional 2 hours to obtain an A-1-1-a solution.

Methanol (80 g), triethylamine (61 g) and 4-dimethylaminopyridine (10 g) were added to the obtained A-1-1-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 59 g of resin A-1-1B.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 34/8/58. Also, the weight average molecular weight (Mw) was 6100 and the degree of dispersion (Mw/Mn) was 1.55.

<Synthesis Example 9: Synthesis of Resin A-1-1C>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, a monomer represented by the following formula M-80 (monomer (M-80)) (51 g) and 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 dimethyl 2,2′-azobisisobutyrate [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 dropwise addition was completed, the reaction solution was stirred at 85° C. for an additional 2 hours to obtain an A-1-1-a solution.

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 the mixture was stirred at 80° C. for 3 hours. Stirred. 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The resulting solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the resulting solid was vacuum-dried to obtain 59 g of resin A-1-1C.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 34/8/58. Also, the weight average molecular weight (Mw) was 6100 and the degree of dispersion (Mw/Mn) was 1.55.

<Synthesis Example 10: Synthesis of Resin A-1-1D>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, a monomer represented by the following formula M-80 (monomer (M-80)) (51 g) and 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 dimethyl 2,2′-azobisisobutyrate [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 dropwise addition was completed, the reaction solution was stirred at 85° C. for an additional 2 hours to obtain an A-1-1-a solution.

1-Methoxy-2-propanol (80 g) and triethylamine (61 g) were added to the obtained A-1-1-a solution, and the mixture was 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 the mixture was stirred until the precipitated solid was 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 with distilled water (1000 mL) five times. The washed organic layer was reprecipitated with a mixed solution of heptane/ethyl acetate=9/1, and filtered. The obtained solid was reslurry-washed with a mixed solution of heptane/ethyl acetate=9/1, filtered, and the obtained solid was vacuum-dried to obtain 63 g of Resin A-1-1.

The compositional ratio (mol% ratio; corresponding from left to right) of each repeating unit measured by ¹³ C-NMR was 34/8/58. Also, the weight average molecular weight (Mw) was 5800 and the degree of dispersion (Mw/Mn) was 1.58.

<Comparative Synthesis Example 1>
Cyclohexanone (45 g) was heated to 85° C. under a stream of nitrogen. While stirring this liquid, 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 dimethyl 2,2′-azobisisobutyrate [V-601, Wako Pure Chemical Industries, Ltd. )] (5.9 g) was added dropwise over 6 hours to obtain a reaction solution. After the dropwise addition was completed, the reaction solution was stirred at 85° C. for an additional 2 hours to obtain an A′-1-1-a solution.

Methanol (80 g) and triethylamine (51 g) were added to the resulting A'-1-1-a solution, 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 confirmed, it was found that the deprotection reaction did not proceed sufficiently (that is, the following reaction proceeded insufficiently).

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

Methanol (114 g) and triethylamine (72 g) were added to the resulting A'-1-4-a solution, 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 confirmed, it was found that the deprotection reaction did not proceed sufficiently (that is, the following reaction proceeded insufficiently).

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of resin which has a favorable productivity and which has a phenolic hydroxyl group can be provided.
On the other hand, according to Comparative Synthesis Examples, some repeating units that could not be deprotected remained, so that a resin containing repeating units having a phenolic hydroxyl group in a desired ratio could not be obtained.

Claims (7)

A method for producing a resin containing a repeating unit (a0) having a phenolic hydroxyl group,
(I) a step of polymerizing a monomer group containing 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 high molecular weight product;
(II) The step of obtaining the phenolic hydroxyl group of the repeating unit (a0) by solvolyzing the protected portion protected by the structure represented by the general formula (1) in the obtained high molecular weight product. Methods of making resins, including in order.

In general formula (1), X represents a halogen atom or an electron-withdrawing group. R ₁ represents a hydroxy group or an organic group. k represents an integer of 0 to 3; n represents an integer from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. * represents the bonding position with the oxygen atom of the phenolic hydroxyl group. 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).

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. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. l represents an integer of 0 to 2; o2 represents an integer from 0 to (4+2l). p2 represents an integer from 1 to (5+2l). However, the relationship 1≤(o2+p2)≤(5+2l) is satisfied. When o2 represents an integer of 2 or more, multiple _R2 may be the same or different. When p2 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different.

In general formula (3), X represents a halogen atom or an electron-withdrawing group. R ₁ 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 from 0 to (4+2k). m represents an integer from 1 to (5+2k). However, the relationship 1≤(n+m)≤(5+2k) is satisfied. When n represents an integer of 2 or more, multiple R _1s may be the same or different. When m represents an integer of 2 or more, multiple X's may be the same or different. o3 represents an integer of 0 to 5; p3 represents an integer of 1-6. However, the relationship 1≤(o3+p3)≤6 is satisfied. When o3 represents an integer of 2 or more, multiple _R3 may be the same or different. When p3 represents an integer of 2 or more, multiple X, R ₁ , k, m and n may be the same or different. X in the general formula (1), (2), or (3) is a halogen atom, a halogenated alkyl group, a nitro group, a cyano group, or a -C (= O) OR group (R represents a hydrocarbon group ), the method for producing a resin according to claim 1 or 2. The method for producing a resin according to any one of claims 1 to 3, wherein the solvolysis in step (II) is performed 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. (III) The method for producing a resin according to any one of claims 1 to 5, comprising a step of contacting the high molecular weight material after completion of step (II) with an acidic aqueous solution. (IV) The method for producing a resin according to any one of claims 1 to 6, comprising a step of mixing a solution containing a high molecular weight material after completion of step (II) with a poor solvent for the high molecular weight material. .