JP5138234B2 - Manufacturing method of resin for semiconductor lithography - Google Patents

Description

  The present invention relates to a method for producing a resin for semiconductor lithography.

In recent years, in the manufacture of semiconductor elements and the like, miniaturization has rapidly progressed due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, in the past, ultraviolet rays typified by g-line and i-line were used, but now KrF excimer laser (248 nm) is the center of mass production, and ArF excimer laser (193 nm) is mass-produced. It has begun to be introduced. Research is also being conducted on lithography technology using an F ₂ excimer laser (157 nm), EUV (extreme ultraviolet light), EB (electron beam) or the like as a light source (radiation source).

A resist material used for lithography using such a light source is required to have high sensitivity to the light source. Further improvements are also required for various lithography characteristics (resolution, depth of focus characteristics, resist pattern shape, etc.) other than sensitivity.
As one of resist materials satisfying such requirements, a chemically amplified resist composition containing a base resin and an acid generator that generates an acid upon exposure is known. The chemically amplified resist composition includes a positive type in which the alkali solubility in the exposed area increases and a negative type in which the alkali solubility in the exposed area decreases.
At present, as a base resin of a chemically amplified resist composition, for example, when a KrF excimer laser is used as a light source, a polyhydroxystyrene (PHS) resin is mainly used. When an ArF excimer laser is used as a light source, a resin (acrylic resin) having a structural unit derived from (α-lower alkyl) acrylic acid in the main chain is generally used. .
In the production of a base resin, the so-called temperature rising batch polymerization method, in which a raw material monomer, a polymerization initiator, and if necessary, a chain transfer agent are dissolved in a polymerization solvent and then polymerized by heating, is most commonly used. It has been.

However, the resist material as described above has a problem that defects are likely to occur on the surface of the resist pattern to be formed. Defects are general defects detected when a developed resist pattern is observed from directly above, for example, with a surface defect observation apparatus (trade name “KLA”) manufactured by KLA Tencor. Examples of such defects include scum, bubbles, dust, bridges (bridge structures between resist patterns), uneven color, and precipitates after development.
Improving the defect becomes important as a resist pattern having high resolution is required. In particular, when an ArF excimer laser is used, that is, when a fine pattern such as a resist pattern of 130 nm or less is formed using ArF excimer laser, F ₂ excimer laser, EUV, EB, etc. as a light source, the problem of defect resolution becomes more severe. ing.

As one of the causes of the defect, there may be a variation in the molecular weight of each molecule constituting the base resin, and a polarity deviation in the molecule.
In other words, the reaction system after the polymerization reaction has a wide range from those having relatively low molecular weights such as unreacted monomers, by-product oligomers and low molecular weight polymers to polymers having a high degree of polymerization and relatively high molecular weights. There is a molecular weight. Each of these molecules has a different solubility in a solvent or an alkaline developer, and this is considered to be one of the causes of worsening the defect.
Currently, in the production of a base resin, two or more types of monomers are usually used as raw material monomers in order to obtain good lithography characteristics. For example, Patent Document 1 discloses, as a monomer, a (meth) acrylic acid ester having an acid dissociable, dissolution inhibiting group in an ester portion, a (meth) acrylic acid ester having a lactone skeleton such as a γ-butyrolactone skeleton in an ester portion, and an ester portion. Describes a polymer using a (meth) acrylic acid ester having a polycyclic group containing a polar group such as a hydroxyl group. And these monomers differ in the reactivity (polymerization rate) in a polymerization reaction, respectively.
For this reason, in the base resin obtained by polymerizing these monomers, structural units derived from the respective monomers are likely to be unevenly distributed in the structure, which is also considered to be one of the causes of worsening the defect.

Variation in molecular weight can be reduced by purifying the resin after polymerization. For example, Patent Document 2 describes that the resin is washed with a lower alcohol such as methanol. This removes unreacted monomers, by-produced oligomers, low molecular weight polymers, and the like.
JP 2003-167347 A JP 2004-231834 A

However, even if a resin manufactured using a conventional purification method is used as a base resin (semiconductor lithography resin), it is difficult to sufficiently suppress the occurrence of defects, particularly bridge-type defects (bridge mode defects). is there.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a resin for semiconductor lithography capable of suppressing the occurrence of defects, particularly bridge mode defects.

The method for producing a resin for semiconductor lithography of the present invention that solves the above-described problem is a resin solution in which a resin for semiconductor lithography (A1) containing a structural unit (a2) having a lactone-containing cyclic group is dissolved in an organic solvent (S1). (R1) is brought into contact with a resin (A1 ′) having a solubility parameter in the range of 17 to 20 (J / cm ³ ) ^1/2 and a specific surface area in the range of 0.005 to ¹ m ² / g. It is characterized by.

In the present specification and claims, “structural unit” means a monomer unit constituting a polymer (resin).
“Exposure” is a concept that includes general irradiation of radiation.

  The present invention provides a method for producing a resin for semiconductor lithography capable of suppressing the occurrence of defects, particularly bridge mode defects.

In the method for producing a resin for semiconductor lithography of the present invention, the resin for semiconductor lithography (A1) (hereinafter sometimes simply referred to as resin (A1)) containing the structural unit (a2) having a lactone-containing cyclic group is organic. The resin solution (R1) dissolved in the solvent (S1) has a solubility parameter in the range of 17 to 20 (J / cm ³ ) ^1/2 and a specific surface area in the range of 0.005 to ¹ m ² / g. It is made to contact resin (A1 ').

<Semiconductor lithography resin (A1)>
Resin (A1) manufactured in this invention should just contain the structural unit (a2) which has a lactone containing cyclic group, and may be arbitrary resin currently used for semiconductor lithography. Specifically, for example, a hydroxystyrene resin, an acrylic resin, and the like can be given, and a resin produced by a radical polymerization reaction is preferable. The present invention is further suitable for the production of a resin proposed as a base resin for a chemically amplified resist composition.
Conventionally, as a resin proposed as a base resin for a chemically amplified resist composition, a resin whose alkali solubility is changed by the action of an acid has been used. Specifically, an alkali-soluble resin or an acid resin is used. Resins having a dissociable dissolution inhibiting group and increasing alkali solubility by the action of an acid are used. The former is for negative resist compositions, and the latter is for positive resist compositions. In the present invention, the resin (A1) may be used for a negative resist composition or a positive resist composition.

When the resin (A1) is for a negative resist composition, the resin (A1) is an alkali-soluble resin. The negative resist composition containing such a resin is blended with the resin, an acid generator component that generates acid upon exposure, and a crosslinking agent. In such a negative resist composition, when an acid is generated from an acid generator component (hereinafter referred to as the component (B)) by exposure during resist pattern formation, the acid acts between the alkali-soluble resin and the crosslinking agent. Crosslinking occurs and changes to alkali insoluble.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.

  When the resin (A1) is for a positive resist composition, the resin (A1) is a resin having an acid dissociable, dissolution inhibiting group and increasing alkali solubility by the action of an acid. The positive resist composition containing such a resin is blended with the resin and component (B). In such a positive resist composition, when an acid is generated from the component (B) by exposure at the time of resist pattern formation, the acid dissociates the acid dissociable, dissolution inhibiting group, whereby the resin (A1) becomes alkali-soluble. . Therefore, in the formation of the resist pattern, when the resist composition applied on the substrate is selectively exposed, the alkali solubility of the exposed portion increases and alkali development can be performed.

The resin (A1) is highly transparent to an exposure light source such as an ArF excimer laser, and has excellent lithographic properties such as resolution. Therefore, the resin (A1) is derived from acrylic acid in both positive and negative types. It is preferable to contain a unit.
Here, in the present specification and claims, “acrylic acid” means acrylic acid in the narrow sense (CH ₂ ═CHCOOH) and derivatives in which part or all of the hydrogen atoms are substituted with other groups or atoms. A concept that includes
Derivatives of acrylic acid include, for example, α-substituted acrylic acid in which a substituent (atom or group other than a hydrogen atom) is bonded to the α-position carbon atom of narrowly defined acrylic acid, or hydrogen of the carboxyl group of these acrylic acids Acrylic esters in which atoms are substituted with organic groups.
The organic group in the acrylate ester is not particularly limited. For example, in the structural units mentioned in the structural units (a1) to (a4) described later, a group (acid dissociation property) bonded to the ester side chain portion of the acrylate ester. Dissolution-inhibiting groups, lactone-containing cyclic groups, polar group-containing aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, and the like.
The α-position (α-position carbon atom) of acrylic acid is a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Examples of the substituent of α-substituted acrylic acid include a halogen atom, a lower alkyl group, a halogenated lower alkyl group and the like.
Examples of the halogen atom as the substituent at the α-position include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present specification, the lower alkyl group is an alkyl group having 1 to 5 carbon atoms.
Specific examples of the lower alkyl group as a substituent at the α-position include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. And a lower linear or branched alkyl group.
Examples of the halogenated lower alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the lower alkyl group have been substituted with the halogen atoms.
Bonded to the α-position of acrylic acid is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a fluorine atom, a lower alkyl group or a fluorinated lower alkyl group. More preferably, it is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.
“Structural unit derived from acrylic acid” means a structural unit formed by cleavage of an ethylenic double bond of acrylic acid.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
Examples of the structural unit derived from acrylic acid include structural units represented by the following general formula (a ″).

［式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｘは水素原子または１価の有機基である］

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and X is a hydrogen atom or a monovalent organic group]

Examples of the halogen atom, lower alkyl group or halogenated lower alkyl group for R include the same as the halogen atom, lower alkyl group or halogenated lower alkyl group as the substituent at the α-position.
Examples of the organic group for X include the same as the above-mentioned “organic group in acrylic ester”.

The resin (A1) preferably contains a structural unit derived from acrylic acid in a proportion of 50 to 100 mol% with respect to the total of all the structural units constituting the resin (A1), and is 70 to 100 mol. % Content is more preferable. In particular, since the effect of the present invention is particularly excellent, the resin (A1) is preferably composed of only a structural unit derived from acrylic acid.
Here, “consisting only of the structural unit (a)” means that the main chain of the resin (A1) is composed only of the structural unit derived from acrylic acid and does not include other structural units. To do.

・ Structural unit (a2)
Resin (A1) contains the structural unit (a2) having a lactone-containing cyclic group as an essential structural unit.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the resin (A1) is used for forming a resist film, the lactone-containing cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or increases the hydrophilicity. It is effective in increasing affinity.
The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Specifically, examples of the lactone-containing monocyclic group include groups obtained by removing one hydrogen atom from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
The lactone-containing monocyclic group may have a substituent on the ring, and examples of the substituent include a lower alkyl group such as a methyl group; an alkoxy group having 1 to 5 carbon atoms.

In the present invention, the structural unit (a2) preferably has a monocyclic or polycyclic lactone-containing cyclic group containing a γ-butyrolactone ring, and particularly contains a monocyclic or polycyclic lactone containing a γ-butyrolactone ring. It preferably has a cyclic group.
Here, “including a γ-butyrolactone ring” means that the lactone-containing cyclic group includes a γ-butyrolactone ring as a lactone ring in the structure, and the lactone-containing cyclic group is a monocyclic ring It may be a formula group or a polycyclic group.
Examples of the monocyclic group containing a γ-butyrolactone ring include the structural unit (a2-1) described later.
Examples of the polycyclic group containing a γ-butyrolactone ring include structural units (a2-2) to (a2-5) described later.

The structural unit (a2) is not particularly limited as long as it has such a lactone ring, and any structural unit proposed as a structural unit having a lactone ring in the base resin for a chemically amplified resist composition can be used. It can be used.
In the present invention, the structural unit (a2) is particularly preferably a structural unit derived from an acrylate ester having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units (a2-1) to (a2-5) represented by general formulas (a2-1) to (a2-5) shown below. .

［式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基であり、Ｒ’は水素原子、低級アルキル基、または炭素数１〜５のアルコキシ基であり、ｍは０または１の整数である。］

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, R ′ is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is 0 or It is an integer of 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as the lower alkyl group for R in the formula (a ″).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in formula (a ″). In general formulas (a2-1) to (a2-5), R ′ is commercially available. In consideration of ease and the like, a hydrogen atom is preferable.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

  Among these, it is preferable to use at least one selected from the general formulas (a2-1) to (a2-3), and it is preferable to use at least one selected from the general formula (a2-1). Further preferred. Specifically, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3) -2), at least one selected from (a2-3-9) and (a2-3-10) is preferably used, and in particular, the chemical formula (a2-1-1) or (a2-1-2) ) Is preferred.

In the resin (A1), as the structural unit (a2), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the resin (A1) is preferably from 5 to 70 mol%, more preferably from 10 to 60 mol%, based on the total of all structural units constituting the resin (A1). 60 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units, and as a resin for semiconductor lithography This is preferable.

・ Structural unit (a1)
In the present invention, when the resin (A1) is for a positive resist composition, the resin (A1) preferably has a structural unit (a1) containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire resin (A1) insoluble in alkali before dissociation, and changes the entire resin (A1) to alkali-soluble after dissociation. If it is a thing, the thing proposed until now as an acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resists can be used. Generally, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group of (meth) acrylic acid, or a group that forms a cyclic or chain alkoxyalkyl ester is widely known. . The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.

Here, the tertiary alkyl ester is an ester formed by replacing the hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O) —O). The structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the oxygen atom at the terminal of-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
The cyclic or chain alkoxyalkyl ester forms an ester by replacing the hydrogen atom of the carboxy group with an alkoxyalkyl group, and the carbonyloxy group (—C (O) —O—) A structure in which the alkoxyalkyl group is bonded to a terminal oxygen atom is shown. In this alkoxyalkyl ester, when an acid acts, a bond is cut between an oxygen atom and an alkoxyalkyl group.

  In the present invention, the structural unit (a1) is particularly preferably a structural unit derived from an acrylate ester having an acid dissociable, dissolution inhibiting group, and in particular, represented by the following general formula (a1-0-1) It is preferable to use 1 or more types selected from the group consisting of the structural unit represented and the structural unit represented by the following general formula (a1-0-2).

（式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。）

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ¹ represents an acid dissociable, dissolution inhibiting group.)

（式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２はアルキレン基または脂肪族環式基を示す。）

(Wherein R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. )

In the general formula (a1-0-1), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is a halogen atom, lower alkyl group or halogenated lower group which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include an alkoxyalkyl group, a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, and the like. Acid dissociable, dissolution inhibiting groups are preferred. Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. A polycyclic group is preferred. The carbon number of the aliphatic cyclic group is preferably 4-20.
Specific examples of such aliphatic cyclic groups include, for example, monocycloalkanes, bicycloalkanes, trialkyls which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. Examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as cycloalkane or tetracycloalkane. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The aliphatic branched acid dissociable, dissolution inhibiting group is preferably a tertiary alkyl group having 4 to 8 carbon atoms, and specific examples include a tert-butyl group and a tert-amyl group.
Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, specifically 2-methyl Examples include a 2-adamantyl group and a 2-ethyl-2-adamantyl group. Alternatively, as a structural unit represented by the following general formula, a group having an aliphatic cyclic group such as an adamantyl group and a branched alkylene group having a tertiary carbon atom bonded thereto can be given.

［式中、Ｒは上記と同じであり、Ｒ^１５、Ｒ^１６はアルキル基（直鎖、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R is the same as described above, and R ¹⁵ and R ¹⁶ represent an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). ]

  Moreover, as said alkoxyalkyl group, group shown by the following general formula (p1) is preferable.

（式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐状または環状のアルキル基である。または、Ｒ^１７とＲ^１９の末端が結合して環を形成していてもよい。）

(Wherein R ¹⁷ and R ¹⁸ are each independently a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ is a linear, branched or cyclic alkyl group, or R ^17. And the end of R ¹⁹ may be bonded to form a ring.)

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of R ^{19 and} the end of R ¹⁷ may be bonded to each other.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

In general formula (a1-0-2), R is the same as defined above. X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group.
When Y ² is a divalent aliphatic cyclic group, it is the same as the description of the “aliphatic cyclic group” in the structural unit (a1) except that a group in which two or more hydrogen atoms are removed is used. Can be used.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［上記式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；ｍは０または１を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; M represents 0 or 1; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

In the R ¹ ′ and R ² ′, at least one is preferably a hydrogen atom, and more preferably both are hydrogen atoms. n is preferably 0 or 1.

X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified in X ¹ above.
Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the description of “aliphatic cyclic group”.

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by General Formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) or (a1-1-35) to (a1- It is more preferable to use at least one selected from structural units represented by 1-41).
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formulas (a1-1-1) to (a1-1-4) The following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41) is also preferable.

（式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、ハロゲン原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す）

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3).

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

  In the resin (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 60 mol%, based on all structural units constituting the resin (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a3)
Resin (A1) includes a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a2) or in addition to the structural units (a1) and (a2). ). By having the structural unit (a3), the hydrophilicity of the resin (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). . As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (a3-3) The structural unit represented by is mentioned as a preferable thing.

（式中、Ｒは前記に同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the resin (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all the structural units constituting the polymer (A2). 5-25 mol% is more preferable.

・ Structural unit (a4)
The resin (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser, for KrF excimer laser (preferably ArF excimer laser). For example, a number of conventionally known resins can be used.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the resin (A1), the structural unit (a4) is contained in an amount of 1 to 30 mol%, preferably 10 to 10% with respect to the total of all the structural units constituting the resin (A1). It is preferable to contain 20 mol%.

  In the present invention, the resin (A1) is preferably a copolymer having at least the structural units (a1) and (a2). Examples of the copolymer include the structural unit (a1) and the structural unit ( a copolymer comprising a2), a copolymer comprising structural units (a1), (a2) and (a3), and a copolymer comprising the structural units (a1), (a2), (a3) and (a4) Etc. can be illustrated.

  In the present invention, the resin (A1) is particularly preferably a copolymer containing four types of structural units in the combination represented by the following general formula (A1-11).

In the formula, R is the same as R in the formula (a ″).
R ⁹ is a lower alkyl group, a lower alkyl group of R ⁹ is the same as the lower alkyl groups described above R, preferably a methyl group or an ethyl group, most preferably a methyl group.

The mass average molecular weight (Mw; polystyrene-converted mass average molecular weight by gel permeation chromatography) of the resin (A1) is not particularly limited, but is preferably 2000 to 30000, more preferably 2000 to 10000, and more preferably 3000 to 7000. preferable. By setting it within this range, a good dissolution rate in an alkaline developer can be obtained, which is preferable from the viewpoint of high resolution. Within this range, the lower the molecular weight, the better characteristics tend to be obtained.
The dispersity (Mw / Mn) is about 1.0 to 5.0, preferably 1.0 to 2.5.

Resin (A1) is a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl-2,2′-azobis (2-methylpropionate), which is a monomer derived from each structural unit. It can obtain by making it superpose | polymerize by well-known radical polymerization etc. using this.
In addition, the resin (A1) is used in combination with a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH at the time of the above-described polymerization. A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

<Organic solvent (S1)>
The organic solvent (S1) should just be what can melt | dissolve resin (A1) and can be set as a uniform solution. Moreover, it is preferable that the organic solvent (S1) does not dissolve the resin (A1 ′).

As the organic solvent (S1), for example, one or two or more kinds of conventionally known solvents for chemically amplified resists can be appropriately selected and used. Specifically, for example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and derivatives thereof;
A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate;
Derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or compounds having ether bonds such as monophenyl ether of the polyhydric alcohols or compounds having an ester bond ;
Cyclic ethers such as dioxane;
Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Examples include aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, amylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
The organic solvent (S1) is selected from the group consisting of propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA); propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether (PGME); and EL More than one species are preferred, among which propylene glycol monoalkyl ether acetate is preferred, and PGMEA is particularly preferred.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the organic solvent (S1), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
There is no restriction | limiting in particular in the usage-amount of an organic solvent (S1), For example, what is necessary is just to set suitably considering the contact method etc. of a resin solution (R1) and resin (A1 '). For example, when the resin solution (R1) is passed through a container filled with the resin (A1 ′), the resin (A1) concentration in the resin solution (R1) is in the range of 2 to 20% by mass in consideration of contact efficiency and the like. The quantity which becomes in the range of 5-15 mass% is more preferable.

<Resin solution (R1)>
The resin solution (R1) can be prepared by dissolving the resin (A1) in the organic solvent (S1).
The resin (A1) can be dissolved in the organic solvent (S1), for example, by simply mixing and stirring the above-mentioned components by a usual method, and if necessary, a dissolver, a homogenizer, a three-roll mill, etc. You may disperse and mix using a disperser. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

<Resin (A1 ′)>
The resin (A1 ′) has a solubility parameter (hereinafter sometimes referred to as “SP value”) in the range of 17 to 20 (J / cm ³ ) ^1/2 and a specific surface area of 0.005 to ¹ m ² / g. It is resin in the range of.
In the present invention, a resin (A1 ′) having an SP value and a specific surface area within such a specific range is brought into contact with an organic solvent (S1) solution of the specific resin (A1). Defects in forming a resist pattern using a resin are reduced.

This is because the resin (A1), which has a relatively high polarity and can cause defects, and the resin (A1 ′) have high affinity, and they are adsorbed on the surface of the resin (A1 ′). This is presumed to be removed from A1).
That is, in the resin (A1) containing the structural unit (a2) having a lactone-containing cyclic group, a monomer (lactone monomer) having a lactone-containing cyclic group used in the production thereof, Are included in the polymer (lactone rich polymer) containing the structural unit (a2) at a high ratio, and these are considered to contribute to the occurrence of defects. For example, lactone-rich polymers have almost no change in alkali solubility before and after exposure. Therefore, in the positive part, the exposed part is in the exposed part, and in the negative part, the part in which the lactone-rich polymer exists is dissolved in the unexposed part. It is considered that it remains as it is and causes a defect (especially a bridge mode defect).
On the other hand, the resin (A1 ′) used in the present invention has an SP value in the range of 17 to 20 (J / cm ³ ) ^1/2 , so that these compounds such as lactone monomers and lactone rich polymers (hereinafter, , Sometimes referred to as a lactone-rich compound)).
Moreover, when the specific surface area of resin (A1 ') is 0.005 m < ² > / g or more, the contact area at the time of making resin solution (R1) contact is large, and a specific surface area is 1 m < ² > / g or less. Thereby, the solution permeability at the time of supplying the resin solution (R1) is also good.
Therefore, by bringing the resin solution (R1) into contact with the resin (A1 ′), the lactone-rich compound contained in the resin solution (R1) is efficiently adsorbed and retained on the resin (A1 ′), and the resin solution ( It is presumed that the amount of the lactone-rich compound in R1) can be reduced to a level sufficient for defect improvement.

[SP value]
The SP value is a parameter representing the solubility of the compound in a solvent. The larger the SP value, the higher the solubility of the compound in a highly polar solvent or a hydrophilic solvent. The smaller the SP value, This means that the compound is highly soluble in a low polarity solvent or a hydrophobic solvent.
In the present invention, the SP value of the resin (A1 ′) is a value calculated using Fujitsu's computational chemistry software CAChe (product name). Specifically, the SP value of the resin (A1 ′) is such that, for each constituent unit of the resin (A1 ′), the atoms constituting the constituent unit and the bond type between the atoms (single bond, double bond, triple bond, etc.) Modeling that inputs the type of bond) as two-dimensional information, and using this two-dimensional information, PM5 method optimizes the structure in which atoms and bond types are arranged three-dimensionally so that the potential energy between atoms is minimized I do. And SP value is calculated about each structural unit which optimized the structure, and it calculates | requires by accumulating the product of the molar composition ratio of each structural unit of resin (A1 '), and SP value of each structural unit mentioned above. it can.
The specific operation method of the structure optimization of the PM5 method by the Fujitsu computational chemistry software CAChe (product name) is described after modeling the structural unit on the Workspace screen of the Fujitsu computational chemistry software CAChe (product name). Select “New” from the pull-down menu of “Experiment”, and in the newly appearing screen, the item “Profession of ::” is “chemical sample”, the item “Property:” is “optimized geometry”, and “Usage: The item “” is to select “Start” after selecting “PM5 geometry”, and the structure can be optimized by this operation.

Examples of the resin having an SP value in the range of 17 to 20 (J / cm ³ ) ^1/2 include the structural unit represented by the following formula (1-1) and the formula (1-2). And a polymer having a structural unit.

The structural unit represented by the formula (1-1) is a structural unit (hereinafter also referred to as GBLMA unit) derived from α-methacryloyloxy-γ-butyrolactone (hereinafter also referred to as GBLMA unit). The SP value of the unit is 18.5 (J / cm ³ ) ^1/2 .
The structural unit represented by the formula (1-2) is a structural unit (hereinafter also referred to as TMPTMA unit) derived from trimethylolpropane trimethacrylate (hereinafter also referred to as TMPTMA unit), and the SP of this structural unit. The value is 17.2 (J / cm ³ ) ^1/2 .
Therefore, for example, the SP value of the polymer of GBLMA unit / TMPTMA unit = 97 mol% / 3 mol% is 18.5 × 0.97 + 17.2 × 0.03 = 18.5 (J / cm ³ ) ^{1 / 2} .
In addition, since the SP values of the GBLMA unit and the TMPTMA unit are both in the range of 17 to 20 (J / cm ³ ) ^1/2 , the SP value of the polymer composed of these two kinds of constituent units is any The composition ratio is also in the range of 17-20 (J / cm ³ ) ^1/2 .

On the other hand, when the GBLMA unit is replaced with, for example, a structural unit derived from acrylonitrile (hereinafter also referred to as AN), the SP value of the AN unit is 24.6 (J / cm ³ ) ^1/2 . The SP value of the polymer of AN / TMPTMA = 97 mol% / 3 mol% is 24.6 × 0.97 + 17.2 × 0.03 = 24.4 (J / cm ³ ) ^1/2 , 17-20 (J / cm ³ ) Out of ^1/2 range.
Here, in the polymer composed of AN units and TMPTMA units, the composition ratio of TMPTMA units having an SP value in the range of 17 to 20 (J / cm ³ ) ^1/2 is increased, and AN / TMPTMA = 37.8 mol. % / 62.2 mol%, the composition ratio is 24.6 × 0.378 + 17.2 × 0.622 = 20.0 (J / cm ³ ) ^1/2 , and the SP value of this polymer is 17 It will be in the range of ˜20 (J / cm ³ ) ^1/2 .

As can be seen from the above examples, when the SP value of all the structural units of the polymer is in the range of 17 to 20 (J / cm ³ ) ^1/2 , the SP value of the polymer is whatever the composition ratio. 17-20 (J / cm ³ ) ^1/2 .
Moreover, when the SP value is larger than 20 (J / cm ³ ) ^1/2 among the structural units of the polymer, the other structural units (SP value is 20 (J / cm ³ ) ^1/2 It is possible to control the SP value of the polymer within the range of 17 to 20 (J / cm ³ ) ^1/2 by increasing the composition ratio of ² or less structural units.
Furthermore, among the structural units of the polymer, when a structural unit having an SP value smaller than 17 (J / cm ³ ) ^1/2 is included, other structural units (SP value is 17 (J / cm ³ ) ¹ By increasing the composition ratio of ^{/ 2} or more, the SP value of the polymer can be controlled in the range of 17 to 20 (J / cm ³ ) ^1/2 .
In this way, the SP value of the polymer is controlled in the range of 17 to 20 (J / cm ³ ) ^1/2 by controlling the composition ratio according to the SP value of each constituent unit of the polymer. It is possible.
In the present invention, it is easy to obtain an SP value in the range of 17 to 20 (J / cm ³ ) ^1/2 , so that the SP values of all the structural units are 17.0 to 20 (J / cm ^3). ) It is preferably in the range of ^1/2 .

[Specific surface area]
The specific surface area of the resin (A1 ′) is in the range of 0.005 to ¹ m ² / g.
The specific surface area is the surface area per unit mass of the powder particles and is determined by a nitrogen adsorption method.
The lower limit of the specific surface area of the resin (A1 ′) is preferably 0.01 m ² / g or more and more preferably 0.03 m ² / g or more from the viewpoint of adsorption and retention of the lactone-rich compound. In addition, the upper limit of the specific surface area of the resin (A1 ′) is preferably 0.8 m ² / g or less, more preferably 0.5 m ² / g or less, from the viewpoint of solution permeability.

The method for adjusting the specific surface area of the resin (A1 ′) to a range of 0.005 to 1 m ² / g is not particularly limited, and a method generally used for adjusting the specific surface area of the resin can be used. For example, when the polymerization of the monomer is performed by suspension polymerization or emulsion polymerization when the resin (A1 ′) is produced, particles of the resin (A1 ′) (suspension particles or emulsion particles) generated by the polymerization are used. What is necessary is just to adjust so that a diameter may become the range of about 6 micrometers-1.2 mm. In order to control these particle sizes, the addition amount of the surfactant may be adjusted in the case of suspension polymerization, and the addition amount of the emulsifier may be adjusted in the case of emulsion polymerization.

  The resin (A1 ′) is not particularly limited as long as it has the SP value and the specific surface area. In particular, since the effect of the present invention is excellent, the resin (A1 ′) preferably contains a structural unit (a2 ′) having a lactone-containing cyclic group. This is because the resin (A1) contains the structural unit (a2) having a lactone-containing cyclic group, and therefore the resin (A1 ′) contains the structural unit (a2 ′), whereby the resin solution of the resin (A1) It is presumed that the removal efficiency of the lactone-rich compound is improved when (R1) is brought into contact with the resin (A1 ′).

Examples of the structural unit (a2 ′) include (meth) acrylate having a δ-valerolactone ring, methylene having a δ-valerolactone ring, norbornene having a δ-valerolactone ring, and tetracyclohexane having a δ-valerolactone ring. Dodecene, (meth) acrylate having γ-butyrolactone ring, methylene having γ-butyrolactone ring, norbornene having γ-butyrolactone ring, tetracyclododecene having γ-butyrolactone ring, (meth) acrylate having alicyclic lactone And a structural unit derived from a monomer having a lactone-containing cyclic group and having a chain polymerization property, such as methylene having an alicyclic lactone, and a derivative having a substituent on the lactone ring of these compounds.
Here, “(meth) acrylate” means one or both of methacrylate and acrylate.
“Alicyclic lactone” means a lactone ring containing a bridged cyclic hydrocarbon group.
Although it does not restrict | limit especially as a monomer which has this lactone containing cyclic group and has chain polymerization property, For example, the monomer represented by following formula (10-1)-(10-37) is mentioned. In formulas (10-1) to (10-37), R represents a hydrogen atom or a methyl group.
Among these, from the viewpoint of good chain polymerizability, monomers represented by the formulas (10-1) to (10-29), and geometric isomers and optical isomers thereof are preferable.

  Examples of the structural unit (a2 ′) include a diol having a δ-valerolactone ring, a dicarboxylic acid having a δ-valerolactone ring, a diamine having a δ-valerolactone ring, a diol having a γ-butyrolactone ring, γ A dicarboxylic acid having a butyrolactone ring, a diamine having a γ-butyrolactone ring, a diol having an alicyclic lactone, a dicarboxylic acid having an alicyclic lactone, a diamine having an alicyclic lactone, and a substituent on the lactone ring of these compounds. And a structural unit derived from a monomer having a lactone-containing cyclic group and having a polycondensation property, such as a derivative thereof.

  Although it does not restrict | limit especially as a monomer which has a lactone containing cyclic group and has polycondensation property, For example, the monomer represented by following formula (10-101)-(10-103) is mentioned.

  In the present invention, the lactone-containing cyclic group in the structural unit (a2 ′) and the lactone-containing cyclic group in the structural unit (a2) preferably have the same structure.

In the resin (A1 ′), as the structural unit (a2 ′), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2 ′) in the resin (A1 ′) is 40 mol% or more with respect to the adsorption and retention of the lactone-rich compound with respect to the total of all the structural units constituting the resin (A1 ′). Preferably, 50 mol% or more is more preferable, and 60 mol% or more is more preferable. In consideration of resistance to the organic solvent (S1) used in the resin solution (R1) to be brought into contact with the resin (A1 ′), 100 mol% or less is preferable, and 99.9 mol% or less is more preferable. 99.5 mol% or less is particularly preferable, 99 mol% or less is more preferable, and 98 mol% or less is most preferable.

The resin (A1 ′) preferably further has a structural unit (a5 ′) derived from a crosslinking agent. When the resin (A1 ′) is a polymer (crosslinked polymer) having such a structural unit, resistance to the organic solvent (S1) and the like are improved.
The crosslinking agent that derives the structural unit (a5 ′) may be any one that can be copolymerized with the monomer that derives the structural unit (a2 ′), and examples thereof include a polyfunctional vinyl monomer (m1).
The polyfunctional vinyl monomer (m1) is a vinyl monomer containing two or more structures having radical polymerizability or ion polymerizability (for example, ethylenic carbon-carbon double bond) in one molecule.
The polyfunctional vinyl monomer (m1) is not particularly limited, and a known polyfunctional vinyl monomer (m1) can be used, for example, a polyfunctional (meth) acrylate monomer, an aromatic polyfunctional monomer Vinyl monomers and aliphatic polyfunctional vinyl monomers can be used. Among these, a polyfunctional (meth) acrylic acid ester monomer is preferable from the viewpoint of polymerizability.

Examples of polyfunctional (meth) acrylic acid ester monomers include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, etc. Alkylene glycol di (meth) acrylates;
Trimethylol ethane tri (meth) acrylate, trimethylol propane tri (meth) acrylate, tetramethylol propane tri (meth) acrylate, tetramethyl roll methane tri (meth) acrylate, tetramethyl roll methane tetra (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2-hydroxy-1,3-di (meth) acryloxypropane, Roxy-1-acryloxy-3-methacryloxypropane, urethane (meth) diacrylate, glycerol di (meth) acrylate, glycerol acrylate methacrylate, 1,10-di (meth) acryloxy-4,7-dioxadecane-2,9- Diol, 1,10-di (meth) acryloxy-5-methyl-4,7-dioxadecane-2,9-diol, 1,11-di (meth) acryloxy-4,8-dioxaoundegan-2,6 , 10-triol, vinyl (meth) acrylate, allyl (meth) acrylate, and the like.
Examples of the aromatic polyfunctional vinyl monomer include divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene, and trivinylbenzene.
Examples of the aliphatic polyfunctional vinyl monomer include 1,3-butadiene.

As the crosslinking agent for deriving the structural unit (a5 ′), a compound having two or more acryloyloxy groups is particularly preferable.
Here, the “acryloyloxy group” is a group represented by the general formula CH ₂ ═CHR—COO—, and examples of R include the same groups as R in the general formula (a ″) described above.
Examples of the structural unit derived from a compound having two or more acryloyloxy groups include a structural unit represented by the following general formula (a5′-1).

［式中、Ｒは上記と同様であり、Ｒ^３は（ｆ＋１）価の飽和炭化水素基であり、ｆは１〜３の整数である。］

[Wherein, R is the same as described above, R ³ is a (f + 1) -valent saturated hydrocarbon group, and f is an integer of 1 to 3. ]

f is an integer of 1 to 3, preferably 1 or 2, and most preferably 2.
R ³ is a (f + 1) valent, that is, a divalent to tetravalent saturated hydrocarbon group, and a divalent saturated hydrocarbon group or a trivalent saturated hydrocarbon group is particularly preferable.
The saturated hydrocarbon group for R ³ may be any of a chain (straight chain, branched chain) and a ring (including only a ring and a chain saturated hydrocarbon group bonded to the ring), A linear or branched saturated hydrocarbon group is more preferred. The saturated hydrocarbon group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 6 carbon atoms.
In the saturated hydrocarbon group for R ³ , the hydrogen atom may be substituted with an atom other than a hydrogen atom. Examples of the other atoms include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom.
R ³ also includes a group in which a part of the carbon atoms of the saturated hydrocarbon group as described above is substituted with a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom.

Examples of the trivalent linear or branched saturated hydrocarbon group include groups in which three hydrogen atoms have been removed from methane, ethane, propane, butane, pentane, hexane, heptane, octane and the like.
The trivalent cyclic saturated hydrocarbon group is a cyclic group obtained by removing three hydrogen atoms from a saturated hydrocarbon ring such as cyclopentane, cyclohexane, cycloheptane, norbornane, isobornane, adamantane, tricyclodecane, and tetracyclododecane. And a group in which a linear or branched alkylene group is bonded to the cyclic group.
Examples of the divalent straight chain or branched saturated hydrocarbon group include a methylene group, an ethylene group, a propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, a pentylene group, an isopentylene group, and a neopentylene group. Is mentioned.
Examples of the divalent cyclic saturated hydrocarbon group include a cyclic group obtained by removing two hydrogen atoms from a saturated hydrocarbon ring such as cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, and tetracyclododecane. And a group in which a linear or branched alkylene group is bonded to the formula group.
R ³ is particularly preferably a trivalent linear or branched saturated hydrocarbon group, and most preferably a group in which three hydrogen atoms have been removed from methane.

In the resin (A1 ′), as the structural unit (a5 ′), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a5 ′) in the resin (A1 ′) is preferably 0.1 mol% or more, more preferably 0.5 mol% or more with respect to the total of all the structural units constituting the resin (A1 ′). More preferably, it is more preferably 1 mol% or more, and particularly preferably 2 mol% or more. Moreover, from the point of adsorption | suction and holding | maintenance of a lactone rich compound, 60 mol% or less is preferable, 50 mol% or less is more preferable, and 40 mol% or less is further more preferable.

The resin (A1 ′) may further contain a structural unit (a6 ′) other than the structural units (a2 ′) and (a5 ′).
The structural unit (a6 ′) is not particularly limited as long as it is derived from a monomer copolymerizable with the monomer that derives the structural unit (a2 ′).
Examples of the monomer copolymerizable with the monomer that derives the structural unit (a2 ′) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and (meth) acrylic acid n. -Propyl, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, methoxymethyl (meth) acrylate, n-propoxyethyl (meth) acrylate, iso-propoxy (meth) acrylate Ethyl, n-butoxyethyl (meth) acrylate, iso-butoxyethyl (meth) acrylate, tert-butoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxy (meth) acrylate Propyl, (meth) acrylic acid 2-hydroxy-n-propyl, (meth) a 4-hydroxy-n-butyl crylate, 2-ethoxyethyl (meth) acrylate, 1-ethoxyethyl (meth) acrylate, 1-adamantyl (meth) acrylate, norbornyl (meth) acrylate, (meth) Tricyclodecanyl acrylate, isobornyl (meth) acrylate, 1- (3-hydroxy) adamantyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, (meth) acrylic acid 2 , 2,3,3-tetrafluoro-n-propyl, 2,2,3,3,3-pentafluoro-n-propyl (meth) acrylate, methyl α-trifluoromethyl acrylate, α-fluoroacrylic acid Methyl, ethyl α-trifluoromethyl acrylate, ethyl α-fluoroacrylate, α-trifluoromethyl acrylate 2-ethyl Ruhexyl, 2-ethylhexyl α-fluoroacrylate, n-propyl α-trifluoromethyl acrylate, n-propyl α-fluoroacrylate, iso-propyl α-trifluoromethyl acrylate, iso-propyl α-fluoroacrylate Α-trifluoromethyl acrylate, n-butyl α-fluoroacrylate, iso-butyl α-trifluoromethyl acrylate, iso-butyl α-fluoroacrylate, tert-α-trifluoromethyl acrylate Butyl, tert-butyl α-fluoroacrylate, methoxymethyl α-trifluoromethyl acrylate, methoxymethyl α-fluoroacrylate, ethoxyethyl α-trifluoromethyl acrylate, ethoxyethyl α-fluoroacrylate, α-trimethyl Fluoromethyla N-propoxyethyl laurate, n-propoxyethyl α-fluoroacrylate, iso-propoxyethyl α-trifluoromethyl acrylate, iso-propoxyethyl α-fluoroacrylate, n-butoxyethyl α-trifluoromethyl acrylate , Α-fluoroacrylic acid n-butoxyethyl, α-trifluoromethyl acrylate iso-butoxyethyl, α-fluoroacrylic acid iso-butoxyethyl, α-trifluoromethyl acrylate tert-butoxyethyl, α-fluoroacrylic acid (meth) acrylic acid ester or α-fluorine-substituted (meth) acrylic acid ester having a linear or branched structure such as tert-butoxyethyl;

  Styrene, α-methylstyrene, vinyltoluene, p-hydroxystyrene, p-tert-butoxycarbonylhydroxystyrene, 3,5-di-tert-butyl-4-hydroxystyrene, 3,5-dimethyl-4-hydroxystyrene, aromatic alkenyl compounds such as p-tert-perfluorobutylstyrene and p- (2-hydroxy-iso-propyl) styrene;

Unsaturated carboxylic acids and carboxylic anhydrides such as (meth) acrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride;
Examples include ethylene, propylene, norbornene, tetrafluoroethylene, acrylamide, N-methylacrylamide, N, N-dimethylacrylamide, vinyl chloride, vinyl fluoride, vinylidene fluoride, and vinylpyrrolidone.

Here, “(meth) acrylic acid” means “methacrylic acid or acrylic acid”.
The “α-fluorine-substituted (meth) acrylic acid ester” means α-fluoromethylacrylic acid in which the hydrogen atom of the methyl group bonded to the α-position carbon atom of methacrylic acid is substituted with a fluorine atom, or acrylic acid The α-fluoroacrylic acid ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a fluorine atom.
In the resin (A1 ′), as the structural unit (a6 ′), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a6 ′) in the resin (A1 ′) is not particularly limited, but is preferably 50 mol% or less with respect to the total of all the structural units constituting the resin (A1 ′).

The resin (A1 ′) used in the present invention is a solid resin and is preferably one that does not dissolve in the organic solvent (S1).
The shape of the resin (A1 ′) is not particularly limited, but is preferably granular in view of contact efficiency with the resin solution (R1). When it is granular, the particle diameter is preferably in the range of about 6 μm to 1.2 mm in consideration of the specific surface area and the like as described above.

[Production of resin (A1 ′)]
The production method of the resin (A1 ′) is not particularly limited, and can be obtained, for example, by polymerizing a monomer that derives each structural unit by a known polymerization method, for example, a chain polymerization method such as radical polymerization.
Specifically, for example, the resin (A1 ′) can be produced by thermal polymerization or photopolymerization of the monomer for deriving each structural unit with a radical polymerization initiator or an ionic polymerization initiator.

  The method for producing the resin (A1 ′) by a chain polymerization method such as radical polymerization is not particularly limited, such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc. From the point that it is easy to form a particle shape, Suspension polymerization and emulsion polymerization are preferred, and suspension polymerization is more preferred from the viewpoint of good powder handleability of the resulting resin (A1 ′).

Although the dispersing agent used when manufacturing resin (A1 ') by suspension polymerization is not specifically limited, For example, poly (meth) acrylic acid alkali metal salt, (meth) acrylic acid, and (meth) acrylic An alkali metal salt of a copolymer of methyl acid, polyvinyl alcohol having a saponification degree of 70 to 100%, methyl cellulose and the like can be mentioned. One or more of these can be appropriately selected and used.
The amount of the dispersant used is preferably in the range of 0.001 to 10% by mass in the aqueous suspension. This is because by making the amount of the dispersant 0.001% by mass or more, the dispersion stability during polymerization tends to be good. More preferably, it is 0.01 mass% or more. Moreover, it is because there exists a tendency for the dehydrating property and drying property of resin (A1 ') to become favorable by setting it as 10 mass% or less. More preferably, it is 1 mass% or less.
As a method for suspension polymerization in the present invention, one or more of the above-mentioned dispersants are dissolved in water, a monomer mixture containing a polymerization initiator is added while stirring, and dispersed into droplets of about 0.05 to 1 mm. The polymerization is preferably performed under heating. At this time, for the purpose of improving the dispersion stability of the droplets, an electrolyte and a pH adjuster can be used as necessary.

Moreover, the addition method of the monomer mixture containing a polymerization initiator may be added to water at once, may be divided into several times, and may be added continuously. Furthermore, when dividing addition or continuous addition is performed using a plurality of monomers, the composition ratio of the monomers may be constant or may be changed. The resin (A1 ′) produced when the monomer composition ratio is changed forms a core-shell type structure in the case of divided addition, and a gradient type structure in the case of continuous addition.
The polymerization temperature during suspension polymerization is not particularly limited, but is preferably in the range of 50 to 130 ° C. This is because, when the temperature is set to 50 ° C. or higher, a polymer can be produced in a relatively short time. More preferably, it is 60 ° C. or higher. Moreover, it is because stability at the time of superposition | polymerization tends to increase by setting it as 130 degrees C or less. More preferably, it is 100 degrees C or less.

The polymerization initiator used during suspension polymerization is not particularly limited, and examples thereof include azo initiators such as azobisisobutyronitrile, peroxide initiators such as benzoyl peroxide, and the like. it can. One or more of these can be appropriately selected and used.
In addition, a chain transfer agent can be used as necessary during suspension polymerization. The chain transfer agent that can be used is not particularly limited, and examples thereof include mercaptans such as n-dodecyl mercaptan, thioglycolic acid esters such as octyl thioglycolate, and α-methylstyrene dimer. These can be appropriately selected and used as necessary.

The resin (A1 ′) can be separated from the aqueous medium by filtering the polymer slurry obtained by suspension polymerization. The separated resin (A1 ′) can be further washed and dried. The resin (A1 ′) subjected to the drying treatment can be extracted with a desired particle diameter by sieving.
The filtration method after suspension polymerization is not particularly limited, but it is preferable to use a filter cloth having an opening of 20 to 100 μm. This is because the emulsified fine particles and the secondary aggregates thereof can be discharged together with the filtrate by setting the mesh size to 20 μm or more. More preferably, it is 40 μm or more. Moreover, it is because it becomes possible to collect | recover favorable resin (A1 ') with a sufficient yield by setting it as 100 micrometers or less. More preferably, it is 75 μm or less.

The washing method after suspension polymerization is not particularly limited, but it is preferable to repeat washing until the filtrate becomes almost transparent using a solvent or water that does not dissolve the resin (A1 ′).
Further, the drying method and the drying temperature are not particularly limited, but it is preferable that the drying is performed under the condition that the residual amount of water or the solvent used for washing is 2% by mass or less. This is to prevent elution of impurities when the resin (A1 ′) is dispersed in various solvents by setting it to 2% by mass or less. More preferably, it is 1 mass% or less.

The resin (A1 ′) obtained in the present invention can be used by being dispersed in an organic solvent such as acetone, ethyl acetate, methyl ethyl ketone, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, and γ-butyrolactone.
The method of dispersing the resin (A1 ′) in the solvent is not particularly limited. For example, the solvent is added to a vessel equipped with a stirring blade and a cooling pipe, and the resin (A1 ′) is gradually added with stirring. After that, it is preferable to maintain the state heated to about 40 to 80 ° C. for about 2 hours.

  At this time, when the monomer for deriving the structural unit (a5 ′) described above is used as the monomer, for example, the polyfunctional vinyl monomer (m1), the crosslinking reaction proceeds from the polyfunctional vinyl monomer (m1), and the crosslinked polymer. Is formed.

  In the production of the resin (A1 ′), the polymer obtained as described above may be further crosslinked by the following method (1) and / or (2) to obtain a crosslinked polymer.

(1) Method using reaction of carboxylic acid or anhydride thereof with epoxy group or isocyanate group In this method, the polymer obtained as described above contains carboxylic acid and / or anhydride thereof, and It can be applied when it contains an epoxy group and / or an isocyanate group.
In this case, the resin (A1 ′) is prepared by mixing a polymer (p1) containing a carboxylic acid and / or an anhydride thereof with a polymer (P2) containing an epoxy group and / or an isocyanate group. The polymer of
After mixing a polymer (P1) containing a carboxylic acid and / or its anhydride and a compound (C1) containing an epoxy group and / or an isocyanate group, these polymers and the compound may be crosslinked,
A compound (C2) containing a carboxylic acid and / or anhydride thereof and a polymer (P2) containing an epoxy group and / or an isocyanate group are mixed, and then the polymer and the compound are crosslinked. be able to.

The polymer (P1) containing a carboxylic acid and / or anhydride thereof is particularly limited as long as the carboxylic acid and / or anhydride thereof is present in the molecular structure (for example, main chain, side chain, terminal, etc.). It will never be done.
The polymer (P1) containing carboxylic acid and / or anhydride thereof uses at least one of a monomer having carboxylic acid or anhydride, an initiator having carboxylic acid, and a chain transfer agent having carboxylic acid. Can be obtained.

  Examples of the monomer having carboxylic acid or its anhydride include unsaturated monocarboxylic acids such as (meth) acrylic acid, α-ethylacrylic acid, crotonic acid, cinnamic acid, vinyl acetic acid, isocrotonic acid, tiglic acid, and angelic acid. Acids; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, alkenyl succinic acid, itaconic acid, mesaconic acid, dimethylmaleic acid, dimethylfumaric acid, monoester derivatives, anhydrides and α- or β-alkyl derivatives thereof Is mentioned.

Examples of the initiator having a carboxylic acid include 4,4′-azobis (4-cyanovaleric acid).
Examples of the chain transfer agent having a carboxylic acid include mercaptoacetic acid, thiosalicylic acid, dithiodiglycolic acid, 3,3′-dithiodipropionic acid, 2,2′-dithiodibenzene acid, DL-2-mercaptomethyl- 3-guanidinoethylthiopropanoic acid, 2-mercapto-4-methyl-5-thiazoleacetic acid, p-mercaptophenol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, (5-mercapto-1,3, 4-thiadiazol-2-ylthio) acetic acid, 2- (5-mercapto-1,3,4-thiadiazol-2-ylthio) propionic acid, 3- (5-mercapto-1,3,4-thiadiazol-2-ylthio) ) Propionic acid, 2- (5-mercapto-1,3,4-thiadiazol-2-ylthio) succinic acid, etc. And the like.

The polymer (P2) containing an epoxy group and / or an isocyanate group is particularly limited as long as a carboxylic acid and / or an anhydride thereof are present in the molecular structure (for example, main chain, side chain, terminal). Never happen.
The polymer (P2) containing an epoxy group and / or an isocyanate group can be obtained by using at least one of a monomer having an epoxy group, a monomer having an isocyanate group, and a chain transfer agent having an epoxy group.

Examples of the monomer having an epoxy group include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, allyl glycidyl ether, allyl β-methyl glycidyl ether, bisglycidyl (meth) acrylate; glycidyl alcohol and unsaturated. Examples thereof include esters of carboxylic acid.
Examples of the monomer having an isocyanate group include 2- (meth) acryloyloxyethyl isocyanate and 1,1-bis (acryloyloxymethyl) ethyl isocyanate.
Examples of the chain transfer agent having an epoxy group include epoxy methyl mercaptan.

The compound (C1) containing an epoxy group and / or an isocyanate group is not particularly limited as long as the epoxy group and / or isocyanate group is present in the molecular structure, but from the viewpoint of the degree of crosslinking, the epoxy group Alternatively, it is preferable that two or more isocyanate groups exist in the molecular structure.
Examples of the compound containing two or more epoxy groups include 1,2: 8,9-diepoxy limonene, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexene carboxylate, and the like.
Examples of the compound containing two or more isocyanate groups include diphenylmethane diisocyanate, toluylene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, trans-1,4-cyclohexane diisocyanate, 1,3-bis- (isocyanatomethyl-benzene). -4,4'-dicyclohexylmethane diisocyanate, 1,3-bis- (isocyanatomethyl) -cyclohexane, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5'-trimethylcyclohexyl isocyanate, meta-tetramethylxylene Examples thereof include diisocyanate and para-tetramethylxylene diisocyanate.

The compound (C2) containing a carboxylic acid and / or an anhydride thereof is not particularly limited as long as the carboxylic acid and / or an anhydride thereof is present in the molecular structure. It is preferable that two or more carboxylic acids exist in the molecular structure, or a cyclic carboxylic acid anhydride.
Examples of the compound containing two or more carboxylic acids in the molecular structure include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, merophanic acid, planitic acid, and pyromellitic acid.
Examples of the cyclic carboxylic acid anhydride include succinic anhydride, phthalic anhydride, naphthalene-1,8: 4,5-tetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic acid = 3. , 4-anhydride.

As a method for producing a polymer (P1) containing a carboxylic acid and / or an anhydride thereof and a polymer (P2) containing an epoxy group and / or an isocyanate group, bulk polymerization, solution polymerization, suspension polymerization, Although it does not specifically limit, such as emulsion polymerization, Solution polymerization and suspension polymerization are preferable from the viewpoint that it is easy to form a sheet shape or a fiber shape.
When the polymer (P1) or the polymer (P2) is produced by solution polymerization, the polymerization method for solution polymerization is not particularly limited, and may be batch polymerization or dropping polymerization. Among them, a polymerization method called dropping polymerization in which a monomer is dropped into a polymerization vessel is preferable because a polymer having a narrow composition distribution and / or molecular weight distribution can be easily obtained. The monomer to be dropped may be a monomer alone or a solution in which the monomer is dissolved in an organic solvent.

In the dropping polymerization method, for example, an organic solvent is charged in a polymerization vessel in advance (this organic solvent is also referred to as a “charged solvent”), heated to a predetermined polymerization temperature, and then a monomer and a polymerization initiator are each independently or arbitrarily selected. In combination, a solution dissolved in an organic solvent (this organic solvent is also referred to as “dropping solvent”) is dropped into the charged solvent. The monomer may be dropped without dissolving in the dropping solvent. In that case, the polymerization initiator may be dissolved in the monomer, or a solution in which only the polymerization initiator is dissolved in the organic solvent is dropped into the organic solvent. May be. Further, the monomer or the polymerization initiator may be dropped into the polymerization vessel in a state where the charged solvent is not in the polymerization vessel.
The monomer and the polymerization initiator may be directly dropped from an independent storage tank to a charged solvent heated to a predetermined polymerization temperature, or immediately before being dropped from an independent storage tank to a charged solvent heated to a predetermined polymerization temperature. And may be added dropwise to the charged solvent.

Furthermore, the timing of dropping the monomer or the polymerization initiator into the charging solvent may be delayed after the monomer has been dropped first, or the polymerization initiator may be dropped with a delay after the monomer has been dropped first. The monomer may be dropped, or the monomer and the polymerization initiator may be dropped at the same timing. These dropping speeds may be constant until the dropping is completed, or may be changed in multiple stages according to the consumption speed of the monomer or the polymerization initiator, or intermittently dropping. May be stopped or started.
Although the polymerization temperature in the dropping polymerization method is not particularly limited, it is usually preferably in the range of 50 to 150 ° C.

As an organic solvent used in the dropping polymerization method, a known solvent can be used as a polymerization solvent. For example, a chain ether such as ether (diethyl ether, propylene glycol monomethyl ether (hereinafter also referred to as “PGME”), tetrahydrofuran ( (Hereinafter also referred to as “THF”), cyclic ethers such as 1,4-dioxane), esters (methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate (hereinafter also referred to as “PGMEA”). ), Ketone (acetone, methyl ethyl ketone (hereinafter also referred to as “MEK”), methyl isobutyl ketone (hereinafter also referred to as “MIBK”), amide (N, N-dimethylacetamide, N, N-dimethylformamide). ), Sulfoxide Such as dimethyl sulfoxide), hydrocarbons (benzene, toluene, xylene and like aromatic hydrocarbons, aliphatic hydrocarbons such as hexane, and alicyclic hydrocarbons such as cyclohexane), and mixtures of these solvents.
These solvents may be used alone or in combination of two or more.

The amount of the polymerization solvent used is not particularly limited and may be determined as appropriate. Usually, it is preferable to use within the range of 30-700 mass parts with respect to 100 mass parts of monomer whole quantity used for copolymerization.
In the dropping polymerization method, when two or more polymerization solvents are used, the mixing ratio of the polymerization solvent in the dropping solvent and the charged solvent can be set at an arbitrary ratio.
The monomer concentration of the monomer solution dropped into the organic solvent is not particularly limited, but is preferably in the range of 5 to 50% by mass.
In addition, the amount of the charged solvent is not particularly limited and may be determined as appropriate. Usually, it is preferable to use within the range of 30-700 mass parts with respect to 100 mass parts of monomer whole quantity used for copolymerization.

  The polymer (P1) and the polymer (P2) are usually polymerized in the presence of a polymerization initiator, respectively, with a monomer having a carboxylic acid or its anhydride and a monomer composition containing an epoxy group and / or an isocyanate group. Is obtained. The polymerization initiator is preferably one that generates radicals efficiently by heat. Examples of such a polymerization initiator are 2,2′-azobisisobutyronitrile (hereinafter also referred to as AIBN) and dimethyl-2,2′-azobisisobutyrate (hereinafter also referred to as DAIB). ), 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and the like; 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, di (4 -Tert-butylcyclohexyl) peroxydicarbonate and other organic peroxides.

In consideration of safety during polymerization, the polymerization initiator preferably has a 10-hour half-life temperature of 60 ° C. or higher.
The amount of the polymerization initiator used is not particularly limited, but from the viewpoint of increasing the yield of the polymer, 0.3 mol part or more is preferable with respect to 100 mol parts of the total amount of monomers used for polymerization, and 1 mol part or more is preferable. More preferably, from the viewpoint of narrowing the molecular weight distribution of the copolymer, 30 mole parts or less is preferable with respect to 100 mole parts of the total amount of monomers used for the polymerization.

  When producing the polymer (P1) or the polymer (P2), the polymer (P1) or the polymer (P2) has a chain transfer agent or epoxy group having a carboxylic acid as long as the crosslinking reaction of the polymer (P1) or the polymer (P2) is not hindered. A chain transfer agent other than the chain transfer agent (hereinafter also referred to as chain transfer agent B) may be used. Examples of such chain transfer agent B include 1-butanethiol, 2-butanethiol, 1-octanethiol, 1-decanethiol, 1-tetradecanethiol, cyclohexanethiol, 2-methyl-1-propanethiol, 2 -Hydroxyethyl mercaptan etc. are mentioned.

The polymer solution produced by solution polymerization is diluted to a suitable solution viscosity with a good solvent such as 1,4-dioxane, acetone, THF, MEK, MIBK, γ-butyrolactone, PGMEA, and PGME as necessary. Then, it is dropped into a large amount of poor solvent such as methanol, water, hexane, heptane, etc. to precipitate the polymer. This process is generally called reprecipitation and is very effective for removing unreacted monomers, polymerization initiators and the like remaining in the polymerization solution. If these unreacted substances remain as they are, there is a possibility of adversely affecting the resist performance. Therefore, it is preferable to remove them as much as possible. The reprecipitation process may be unnecessary depending on circumstances.
Thereafter, the precipitate is filtered off and sufficiently dried to obtain a polymer (P1) and a polymer (P2). Moreover, after filtering off, it can also be used with a wet powder, without drying.

  Moreover, when manufacturing a polymer (P1) and a polymer (P2) by suspension polymerization, the method of suspension polymerization is as above-mentioned.

As a method for producing a resin (A1 ′) by reacting a carboxylic acid or its anhydride with an epoxy group or an isocyanate group using the polymer (P1) or polymer (P2) produced by the above-described method. Is a combination of polymer (P1) and polymer (P2), polymer (P1) and compound (C1), polymer (P2) and compound (C2), dissolved in various solvents, It is preferable to perform a crosslinking reaction by forming a film, spinning or the like and heating the molded product.
The end point of the reaction between the carboxylic acid or its anhydride and the epoxy group or the isocyanate group is a cross-linking reaction point in the reaction liquid by using liquid chromatography (LC) or gas chromatography (GC) as the reaction liquid. The end point of the reaction can be confirmed by analyzing the carboxylic acid, the epoxy group, or the isocyanate group and not having these crosslinking reaction points remaining. Even during the reaction, a large amount of a compound containing only one epoxy group and / or isocyanate group or a compound containing only one carboxylic acid and / or its anhydride is added to the reaction solution. The reaction can also be terminated by deactivating the crosslinking reaction point.

(2) Method Using Reaction of Hydroxyl Group with Isocyanate Group This method can be applied when the polymer obtained as described above contains a hydroxyl group and / or contains an isocyanate group.
In this case, the resin (A1 ′) is prepared by mixing the polymer (P3) containing a hydroxyl group and the polymer (P4) containing an isocyanate group, and then crosslinking these polymers.
After mixing the polymer (P3) containing a hydroxyl group and the compound (C3) containing an isocyanate group, these polymers and the compound may be crosslinked,
The compound (C4) containing a hydroxyl group and the polymer (P4) containing an isocyanate group can be mixed, and then the polymer and the compound can be crosslinked.

The polymer (P3) containing a hydroxyl group is not particularly limited as long as a hydroxyl group is present in the molecular structure (eg, main chain, side chain, terminal).
The polymer (P3) containing a hydroxyl group can be obtained by using at least one of a monomer having a hydroxyl group, an initiator having a hydroxyl group, and a chain transfer agent having a hydroxyl group.

Examples of the monomer having a hydroxyl group include vinyl phenol, vinyl naphthol, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.
Examples of the initiator having a hydroxyl group include 2,2′-azobis (2-methyl-N- (1,1-bis (hydroxymethyl) -2-hydroxyethyl) propionamide), 2,2′-azobis ( 2-methyl-N- (2- (1-hydroxybutyl)) propionamide), 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) propionamide) and the like.
Examples of the chain transfer agent having a hydroxyl group include 2-mercaptoethanol and thioglycerol.

The polymer (P4) containing an isocyanate group is not particularly limited as long as the isocyanate group exists in the molecular structure (for example, main chain, side chain, terminal).
The polymer (P4) containing an isocyanate group can be obtained by using a monomer having an isocyanate group.
Examples of the monomer having an isocyanate group include 2- (meth) acryloyloxyethyl isocyanate and 1,1-bis (acryloyloxymethyl) ethyl isocyanate.

The isocyanate group-containing compound (C3) is not particularly limited as long as the isocyanate group is present in the molecular structure, but two or more isocyanate groups are present in the molecular structure from the viewpoint of the degree of crosslinking. It is preferable.
Examples of the compound containing two or more isocyanate groups include diphenylmethane diisocyanate, toluylene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, trans-1,4-cyclohexane diisocyanate, 1,3-bis- (isocyanatomethyl-benzene). -4,4'-dicyclohexylmethane diisocyanate, 1,3-bis- (isocyanatomethyl) -cyclohexane, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5'-trimethylcyclohexyl isocyanate, meta-tetramethylxylene Examples thereof include diisocyanate and para-tetramethylxylene diisocyanate.

The hydroxyl group-containing compound (C4) is not particularly limited as long as a hydroxyl group is present in the molecular structure, but it is preferable that two or more hydroxyl groups are present in the molecular structure from the viewpoint of the degree of crosslinking. .
Examples of the compound containing two or more hydroxyl groups include 1,2-propanediol, 5-methyl-1,3-benzenediol, 2-hydroxybenzenemethanol, 2-((9-hydroxynonyl) oxy) phenol, and the like. Can be mentioned.

A method for producing a polymer (P3) containing a hydroxyl group or a polymer (P4) containing an isocyanate group is not particularly limited, such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc. In view of easy formation of the fiber shape, solution polymerization and suspension polymerization are preferable.
When the polymer (P3) or the polymer (P4) is produced by solution polymerization, the solution polymerization method is the same as that of the polymer (P1) or polymer (P2) described above.
Moreover, when manufacturing a polymer (P1) and a polymer (P2) by suspension polymerization, the method of suspension polymerization is the same as that of the above-mentioned polymer (P1) and polymer (P2).
And as a method of manufacturing resin (A1 ') of this invention by reaction of a hydroxyl group and an isocyanate group using the polymer (P3) manufactured by the above-mentioned method, a polymer (P4), etc., it is heavy. The polymer (P3) and the polymer (P4), the polymer (P3) and the compound (C3), the combination of the polymer (P4) and the compound (C4), dissolved in various solvents, and then formed into a film by a known method. A method is preferred in which the crosslinking reaction is carried out by performing molding such as spinning and spinning and heating the molded product.
The end point of the reaction between the hydroxyl group and the isocyanate group is determined by analyzing the hydroxyl acid or isocyanate group, which is a crosslinking reaction point in the reaction solution, using LC or GC as the reaction solution, and these crosslinking reaction points remain. By not doing so, the end point of the reaction can be confirmed. In addition, even during the reaction, a compound containing only one isocyanate group or a compound containing only one hydroxyl group is put in a large amount in the reaction solution to deactivate the crosslinking reaction point. Can also be terminated.

(Purification of resin (A1 ′))
Resin (A1 ′) after polymerization or cross-linking contains unnecessary substances such as unreacted monomers, oligomers and other low molecular weight components, polymerization initiators, chain transfer agents and reaction residues thereof. ) Is preferably subjected to a purification treatment after polymerization.

In the present invention, the resin (A1 ′) is preferably purified by the following purification method (P1) because the effect of reducing defects, particularly bridge mode defects, is excellent.
Purification method (P1): Step (i) of washing the resin (A1 ′) with an organic solvent (S1 ′) having a solubility parameter in the range of 17.0 to 20.5 (J / cm ³ ) ^1/2 Having a purification method.

The polymerized resin (A1 ′) is a lactone-rich polymer containing a relatively low molecular weight compound (unreacted monomer, by-product oligomer), a low molecular weight polymer, and a structural unit (a2 ′) in a high proportion. (Hereinafter these are collectively referred to as unnecessary items). In the purification method (P1), it is presumed that these unnecessary substances, particularly lactone-rich polymers can be effectively removed by carrying out step (i).
That is, in this purification method, in step (i), washing is performed using an organic solvent (S1 ′) having a solubility parameter in the range of 17.0 to 20.5 (J / cm ³ ) ^1/2. Therefore, it is considered that unnecessary substances existing on the surface and / or inside of the resin (A1 ′) are dissolved in the organic solvent (S1 ′) to remove impurities.

-Process (i):
The organic solvent (S1 ′) used in the step (i) is an organic solvent having a solubility parameter in the range of 17.0 to 20.5 (J / cm ³ ) ^1/2 .
Since the organic solvent (S1 ′) is used for washing the resin (A1 ′), it is preferably a solvent that does not dissolve the resin (A1 ′).
As the organic solvent (S1 ′), γ-butyrolactone (SP value 18.4 (J / cm ³ ) ^1/2 ), propylene glycol monomethyl ether acetate (SP value 17.8 (J / cm ³ ) ^1/2 ) , Tetrahydrofuran (SP value 18.6 (J / cm ³ ) ^1/2 ), ethyl acetate (SP value 18.6 (J / cm ³ ) ^1/2 ), methyl ethyl ketone (SP value 19.0 (J / cm ³⁾ ) ^1/2 ), toluene (SP value 18.2 (J / cm ³ ) ^1/2 ), and cyclohexanone (SP value 20.3 (J / cm ³ ) ^1/2 ) It is preferable to include. Among these, γ-butyrolactone is most preferable from the viewpoints of excellent effects of the present invention and availability.
In the present invention, the SP value of the organic solvent (S1 ′) is a value calculated using the computational chemical software CAChe (product name) manufactured by Fujitsu.

  Cleaning may be performed once or may be performed twice or more.

In the step (i), the washing can be performed, for example, by adding an organic solvent (S1 ′) in an amount not less than the mass of the resin (A1 ′) to the resin (A1 ′).
The temperature at which the resin (A1 ′) is washed is not particularly limited, but is preferably 20 ° C. or higher, and more preferably 30 ° C. or higher in order to increase the solubility of impurities. Moreover, in order to prevent quality change of resin (A1 '), 100 degrees C or less is preferable and 80 degrees C or less is more preferable.
The amount of the organic solvent (S1 ′) used is not particularly limited, but is preferably 1.5 times by mass or more with respect to the mass (solid content) of the resin (A1 ′) because it is excellent in the effects of the present invention. It is more preferably at least 0 times by mass. The upper limit is preferably 20 times by mass or less and more preferably 15 times by mass or less in consideration of processing efficiency, cost, and the like.

The resin (A1 ′) after the step (i) contains the organic solvent (S1 ′) used during purification.
Such a resin (A1 ′) may be obtained by removing the organic solvent (S1 ′) by drying under reduced pressure or the like, or may be used as it is in a purification process of a resin for lithography.

-Process (ii):
In the purification method (P1), after the step (i), the resin (A1 ′) washed in the step (i) is not dissolved in the resin (A1 ′) and the organic solvent (S1 ′). The step (ii) of washing with an organic solvent (S2 ′) that is miscible with A may be performed.
The organic solvent (S2 ′) used in the step (ii) does not dissolve the resin (A1 ′) and is miscible with the organic solvent (S1 ′).
Here, “having miscibility with the organic solvent (S1 ′)” means that when a double amount of the organic solvent (S1 ′) is added at 80 ° C., a uniform solution is obtained.
Further, since the organic solvent (S2 ′) is used for washing the resin (A1 ′), it needs to be a solvent that does not dissolve the resin (A1 ′).

Specific examples of the organic solvent (S2 ′) include propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, methyl ethyl ketone, propylene glycol monomethyl ether, and cyclohexanone.
When the organic solvent (S1 ′) is the above-mentioned γ-butyrolactone, the organic solvent (S2 ′) is a propylene glycol monoalkyl in terms of good miscibility with γ-butyrolactone and availability. Ether acetate is preferred, and PGMEA is particularly preferred.

In step (ii), the washing can be performed, for example, by adding an organic solvent (S2 ′) in an amount equal to or larger than the mass of the resin (A1 ′) to the resin (A1 ′).
The temperature at which the resin (A1 ′) is washed is not particularly limited, but is preferably 20 ° C. or higher, and more preferably 40 ° C. or higher in order to increase the solubility of impurities. Moreover, in order to fully prevent the resin (A1 ′) from being deteriorated, the temperature is preferably 100 ° C. or lower, and more preferably 80 ° C. or lower.
The amount of the organic solvent (S2 ′) used is not particularly limited, but is preferably 1.5 times by mass or more with respect to the mass (solid content) of the resin (A1 ′) because it is excellent in the effects of the present invention. It is more preferably at least 0 times by mass. The upper limit is preferably 20 times by mass or less and more preferably 15 times by mass or less in consideration of processing efficiency, cost, and the like.

Cleaning may be performed once or may be performed twice or more. In the present invention, it is preferable to perform washing with the organic solvent (S2 ′) until the organic solvent (S1 ′) can be completely removed from the resin (A1 ′).
Whether or not the organic solvent (S1 ′) has been completely removed from the resin (A1 ′) can be determined by, for example, analyzing the organic solvent (S2 ′) after washing the resin (A1 ′) by gas chromatography (GC) or the like. This can be confirmed by measuring the concentration of the organic solvent (S1 ′) in the organic solvent (S2 ′). When the organic solvent (S1 ′) is contained in the organic solvent (S2 ′), the cleaning process is repeated until the organic solvent (S1 ′) cannot be detected.

The resin (A1 ′) after the step (ii) contains the organic solvent (S2 ′) used during purification.
Such resin (A1 ′) may be obtained by removing the organic solvent (S2 ′) by drying under reduced pressure or the like, or may be used as it is in a purification process of a resin for lithography.

-Process (iii):
In the purification method (P1), after the step (i) or (ii), the organic solvent (S1 ′) or (S2 ′) is not dissolved in the resin (A1 ′) and the organic solvent. You may perform the process (iii) substituted with the organic solvent (S3 ') of lower boiling point than (S1') or (S2 ').

  When the organic solvent (S1 ′) or (S2 ′) is the above-described propylene glycol monoalkyl ether acetate, the organic solvent (S3 ′) has good miscibility with propylene glycol monoalkyl ether acetate, From the standpoint of ease, tetrahydrofuran (THF; boiling point 66 ° C.) is preferable.

  The amount of the organic solvent (S3 ') used is not particularly limited as long as the organic solvent (S2') can be completely removed from the resin (A1 '). Usually, it is preferably in the range of 1.5 to 20 times by mass and more preferably in the range of 2 to 15 times by mass with respect to the mass of the resin (A1 ′). When it is at least the lower limit value, the effect of removing the organic solvent (S2 ') is excellent, and when it is at most the upper limit value, the solvent can be replaced in a short time.

After the solvent replacement, the organic solvent (S3 ′) may be removed, or may be used as it is for the purification process of the lithography resin.
The removal of the organic solvent (S3 ′) from the resin (A1 ′) can be performed, for example, by heating at a temperature not higher than the boiling point of the organic solvent (S3 ′).

More specifically, the purification method (P1) can be performed, for example, by the following procedure.
First, the organic solvent (S1 ′) is added to the solid resin (A1 ′), and the mixture is stirred for 0.5 to 10 hours at 20 to 80 ° C. to absorb the organic solvent (S1 ′) in the resin (A1 ′). (Swell).
Next, washing is performed by optionally adding and removing the organic solvent (S2 ′) to the resin (A1 ′). The addition / removal of the organic solvent (S2 ′) is preferably performed until the organic solvent (S1 ′) in the resin (A1 ′) is completely removed.
Next, optionally, an organic solvent (S3 ′) is added to the resin (A1 ′), and the mixture is stirred at 20 to 80 ° C. for 0.5 to 10 hours to remove the organic solvent (S3 ′). Dry.
In this way, a purified resin (A1 ′) is obtained.

<Contact method>
The method for bringing the resin solution (R1) in which the resin (A1) is dissolved in the organic solvent (S1) into contact with the resin (A1 ′) is not particularly limited. For example, it is generally used for bringing a liquid and a solid into contact with each other. For example, filling a resin (A1 ′) into a liquid-permeable container such as a column and passing the resin-permeable container through the resin solution (R1); into the resin solution (R1) Examples thereof include a method of adding and stirring the resin (A1 ′).

In the present invention, from the viewpoint of easy separation of the resin solution (R1) and the resin (A1 ′), the resin (A1 ′) is filled in a liquid-permeable container, and the liquid can be passed. A method of passing the inside of the container through the resin solution (R1) is preferable.
As a method for allowing the resin solution (R1) to pass through the container through which liquid can flow, for example, the resin solution (R1) is put in a cylindrical container filled with the resin (A1 ′) and then dropped (eluted) by gravity. ) And a method of continuously passing the resin solution (R1) through the cylindrical container filled with the resin (A1 ′).
As shown in FIG. 1, the cylindrical container can prevent the granular resin (A1 ′) 2 filled in the casing from flowing out to both ends of the cylindrical casing 1, and can be a resin solution (R1). It is preferable to be able to install filters 3 and 4 that can pass through, and as such containers, for example, commercially available columns can be used.
Instead of the filters 3 and 4, a fiber having the same function, for example, a fiber such as cotton may be packed at both ends of the cylindrical container.
As a method of using such a cylindrical container, for example, as shown in FIG. 1, a filter 4 is disposed at one end of the cylindrical casing 1, for example, below, and the granular resin (A1 ′) 2 is dispersed. The resin (A1 ′) 2 is filled by pouring the liquid into the housing 1, and then the filter 3 is disposed thereon. And the resin solution (R1) is poured from the upper part of the filter-3, and the resin solution (R1) is continuously passed through the cylindrical container filled with the resin (A1 ′) by dropping (eluting) by gravity. By allowing the liquid to pass, the resin solution (R1) can be brought into contact with the resin (A1 ′).
Among these, the method of dropping (eluting) is preferable because the effect of removing the lactone-rich polymer is high and the effect of the present invention is excellent.
The elution rate at the time of dropping is not particularly limited and is preferably in the range of 0.1 to 5 ml / second, more preferably 0.15 to 4 ml / second, and 0.2 to 3.5 ml / second. Further preferred. Within the above range, the bridge mode defect reduction effect is excellent. Further, when it is at least the lower limit value, the production efficiency is good, and when it is at most the upper limit value, the total number of defects can be reduced.

(Other processes)
Moreover, in this invention, before making resin solution (R1) and resin (A1 ') contact, an organic solvent (S4) is added to resin solution (R1), and the density | concentration of resin (A1) is reduced. It is preferable to perform a process (dilution process). As a result, by-products contained in the resin (A1) (for example, oligomers or low molecular weight polymers produced as a by-product in the polymerization reaction, or polymers having a higher molecular weight than the target mass average molecular weight, in particular, the content ratio of a specific structural unit) The amount of the polymer, oligomer, etc. having a high composition bias can be reduced, and the effect of the present invention is further improved.

As an organic solvent (S4), the thing similar to what was illustrated as an organic solvent (S1) is mentioned.
The addition amount of the organic solvent (S4) is preferably 2 times or more, more preferably 4 to 5 times the mass of the resin solution (R1).
At this time, when the concentration of the resin (A1) in the resist composition in which the resin (A1) is used is C1, and the concentration of the resin (A1) in the diluted resin solution (R1) is C2. It is preferable to add the organic solvent (S4) so that C2 is smaller than C1, because the effects of the present invention are excellent.
Here, in general, the wavelength of the exposure light source is 248 nm or less (for example, KrF, ArF, or F ₂ excimer laser light, Extreme UV (extreme ultraviolet light), EB (electron beam), or X-ray). Although it does not specifically limit as base resin density | concentration C1 in corresponding resist composition, Since it can provide the suitable film thickness with respect to an exposure light source, Preferably it is 2-20 mass%, More preferably, it is 5-15 mass%. Has been prepared.
C2 should just be prepared so that it may become smaller than C1, as mentioned above, The numerical value is not limited. Therefore, C2 should just be less than the numerical value of said C1.

  In the diluting step, for example, the organic solvent (S4) is added to the resin solution (R1), and preferably stirred at 10 to 40 ° C., preferably at 20 to 30 ° C., for 10 to 60 minutes, preferably 25 to 35 minutes. It can be carried out by performing a process or the like.

In the present invention, before bringing the resin solution (R1) and the resin (A1 ′) into contact with each other, the resin solution (R1) can be separated into an organic solvent (S1) and two layers such as water. You may perform the process (water washing process) wash | cleaned using (S5). Thereby, the oligomer and the low molecular weight polymer in the resin (A1), in particular, the oligomer having a relatively high polarity and the low molecular weight polymer (such as a lactone rich polymer) can be dissolved in the aqueous layer and removed.
As the aqueous solvent (S5), water is preferably used.

As a specific operation, for example, an aqueous solvent (S5) is first added to the resin solution (R1). At this time, the use ratio (mass ratio) of the organic solvent (S1) and the aqueous solvent (S5) in the resin solution (R1) is not particularly limited as long as it can be separated into two layers. S1): aqueous solvent (S5) = 1: 1 to 4: 1 (mass ratio) is preferable, and 2: 1 to 3: 1 is more preferable. When the use ratio of the aqueous solvent (S5) is 4: 1 or more, a sufficient cleaning effect can be obtained, and when it is 1: 1 or less, the organic solvent (S1) is well separated, and the resin (A1) is aqueous. It is difficult to move to the solvent (S5) phase, and the resin (A1) can be recovered with a good yield, which is effective for improving productivity and reducing costs.
Next, after adding the aqueous solvent (S5) to the resin solution (R1), it is 10 to 40 ° C., preferably 20 to 30 ° C., 10 to 60 minutes, preferably 25 to 35 minutes, by stirring, shaking, etc. Wash.
Next, when the stirring and the like are finished and the liquid is allowed to stand, the organic solvent (S1) phase is an upper layer and the aqueous solvent (S5) phase is a lower layer. The lower aqueous solvent (S5) phase is removed from the liquid divided into two layers, and the organic solvent (S1) phase in which the resin (A1) is dissolved is recovered.
The water washing step may be performed once or twice or more.

Furthermore, in the present invention, before and / or after contacting the resin solution (R1) and the resin (A1 ′), a step of passing the resin solution (R1) through a filter having a filtration membrane (filtration step) is performed. It is preferable.
There is no restriction | limiting in particular as said filter, The arbitrary filters conventionally used for filtration of resin solutions etc. can be used.
Examples of the filter membrane include a fluorine resin such as PTFE (polytetrafluoroethylene); a polyolefin resin such as polypropylene and polyethylene; and a polyamide resin such as nylon 6 and nylon 66.
In the present invention, in particular, a filter provided with at least one selected from three types of filter membranes made of nylon such as nylon 66 and nylon 6, a filter membrane made of polyethylene, and a filter membrane made of polypropylene is used. In particular, it is preferable to use a filter having a nylon filtration membrane. By using a filter equipped with these filtration membranes, it is possible to effectively remove oligomers and low molecular weight polymers by-produced in the polymerization reaction, polymers having a higher molecular weight than the target mass average molecular weight, As a result, the effect of the present invention is further improved.
The pore size of the filter is preferably 0.02 to 0.1 μm, more preferably 0.02 to 0.05 μm. Moreover, when the pore diameter of the filter is 0.02 μm or more, the filtration rate can be increased, and good productivity is maintained. Moreover, when it is 0.1 μm or less, an oligomer or a low molecular weight polymer by-produced by a polymerization reaction, or a polymer having a higher molecular weight than the target mass average molecular weight can be effectively removed.

  Filtration may be performed in one stage or in two or more stages. Moreover, the kind of filtration membrane and filter to be used may be 1 type, and may use 2 or more types together.

The resin solution (R1) thus obtained may be adjusted to a concentration suitable for semiconductor lithography using the resin (A1) by removing (concentrating) a certain amount of organic solvent. Such a resin solution is preferable because it can be used as it is as a resin solution for preparing a resist composition, for example, a resist composition can be efficiently produced by preparing an acid generator component and other optional components in the resin solution.
Further, the resin solution (R1) can be used for semiconductor lithography such as the production of a resist composition as a solid resin by completely removing the organic solvent.

≪Resist composition≫
The resin (A1) produced by the production method of the present invention is used for semiconductor lithography, and is particularly suitably used as a resin component of a resist composition. Among these, as described above, the base component (A) ((A) component) whose alkali solubility is changed by the action of an acid, and the acid generator component (B) (( In the chemically amplified resist composition containing B) component)), it can be suitably used as the substrate component (A).
The resist composition may be a positive type or a negative type as long as it contains the resin (A1) as the component (A). A positive type is preferred.

In the case of the negative type, a crosslinking agent is blended in the resist composition together with the alkali-soluble resin and the component (B). When an acid is generated from the component (B) by exposure at the time of resist pattern formation, the acid acts to cause cross-linking between the alkali-soluble resin and the cross-linking agent, thereby changing to alkali-insoluble.
Examples of the crosslinking agent include, for example, an amino-based crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, particularly a butoxymethyl group, a melamine-based crosslinking agent, a urea-based crosslinking agent, or an ethyleneurea-based crosslinking agent. Is preferable because a good resist pattern can be formed. The blending amount of the crosslinking agent is preferably in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

  In the case of the positive type, the component (A) is an alkali-insoluble one having a so-called acid dissociable dissolution inhibiting group, and when acid is generated from the component (B) by exposure, the acid is converted into the acid dissociable dissolution inhibiting group. (A) component becomes alkali-soluble by dissociating. Therefore, in the formation of the resist pattern, when the resist composition applied on the substrate is selectively exposed, the alkali solubility of the exposed portion increases and alkali development can be performed.

[(A) component]
In this invention, (A) component is resin (A1) manufactured by the manufacturing method of the said invention.
In the present invention, in addition to the resin (A1), other resin components that can be used for the resist composition, such as a known polyhydroxystyrene resin and (meth) acrylic resin, can be appropriately blended. For the effect of the invention, the proportion of the resin (A1) in the component (A) contained in the resist composition is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100%. % By mass.
The proportion of the component (A) in the resist composition can be appropriately adjusted depending on the intended resist film thickness.

[Component (B)]
The component (B) can be used without particular limitation from known acid generators used in conventional chemically amplified resist compositions.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  Specific examples of the onium salt-based acid generator include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, and triphenylsulfonium trifluoromethane. Sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethane Sulfonate, its heptafluoropropane sulphonate or its Nafluorobutane sulfonate, trifluoromethane sulfonate of monophenyldimethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluoromethane sulfonate of diphenylmonomethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4- Trifluoromethanesulfonate of methylphenyl) diphenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of (4-methoxyphenyl) diphenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, tri (4 -Tert-bu Le) trifluoromethanesulfonate triphenylsulfonium, its like heptafluoropropane sulfonate or nonafluorobutane sulfonates.

  Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyl). Oxyimino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzene Sulfonyloxyimino) -2,4-dichlorobenzylcyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzylcyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzylcyanide, α- (2-Chlorobenzenesulfonyloxyimi ) -4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxy) Imino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1 -Cyclopentenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloo Tenenyl acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cycl Lopentenylacetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino)- - methoxyphenyl acetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile. Of these, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile is preferred.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type. As the component (B), an onium salt having a fluorinated alkyl sulfonate ion as an anion is particularly preferable.
Content of (B) component in a resist composition is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-10 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[Optional ingredients]
The resist composition may further contain a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component in order to improve the resist pattern shape, stability over time, and the like. .
Since a wide variety of components (D) have already been proposed, any known one may be used. Cyclic amines, aliphatic amines, particularly secondary aliphatic amines and tertiary fats may be used. Group amines are preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n-heptylamine, Dialkylamines such as di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptyl Trialkylamines such as amine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n -Ok Noruamin, alkyl alcohol amines such as tri -n- octanol amine.
Among these, alkyl alcohol amines and trialkyl amines are preferable, and alkyl alcohol amines are most preferable. Of the alkyl alcohol amines, triethanolamine and triisopropanolamine are most preferred.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

In the resist composition, an organic carboxylic acid or an oxo acid of phosphorus or a derivative thereof (E) (hereinafter referred to as an optional component) is used for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, etc. (E) component) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester and other phosphoric acid or derivatives thereof such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid- Like phosphonic acids such as di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof, phosphinic acids such as phosphinic acid, phenylphosphinic acid and their esters Derivatives.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The resist composition may further contain miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coating properties, dissolution inhibitors, plasticizers, stabilizers. Further, a colorant, an antihalation agent, a dye and the like can be added and contained as appropriate.

The resist composition can be produced by dissolving the material in an organic solvent (S) (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and derivatives thereof;
A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate;
Derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or compounds having ether bonds such as monophenyl ether of the polyhydric alcohols or compounds having an ester bond ;
Cyclic ethers such as dioxane;
Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Examples include aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, amylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5-15% by mass.

  The material can be dissolved in the component (S), for example, by simply mixing and stirring the above components by a usual method. If necessary, a disperser such as a dissolver, a homogenizer, or a three-roll mill is used. It may be dispersed and mixed. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

<Resist pattern formation method>
The resist pattern forming method using the resist composition can be performed, for example, as follows.
First, the positive resist composition is applied onto a substrate such as a silicon wafer with a spinner or the like, and pre-baked (post-apply bake (PAB)) is performed at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 For 90 seconds, and selectively exposed to ArF excimer laser light through a desired mask pattern using, for example, an ArF exposure apparatus, and then subjected to PEB (post-exposure heating) at a temperature of 80 to 150 ° C. It is applied for -120 seconds, preferably 60-90 seconds. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide. In this way, a resist pattern faithful to the mask pattern can be obtained.
An organic or inorganic antireflection film can be provided between the substrate and the coating layer of the resist composition.
The wavelength used for the exposure may be appropriately set according to the type of the resin (A1). For example, ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB ( Any one of radiations such as electron beam), X-rays, and soft X-rays can be selected and used.

Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.
The measurement methods used in the following synthesis examples and examples are shown below.
<Polymerization conversion>
The polymerization conversion rate of the resin (polymer) was determined by determining the amount of unreacted monomer present in the polymerization reaction solution for each monomer and calculating the consumption rate for each monomer in reverse.

  In the case of a polymer produced by suspension polymerization, the amount of monomer remaining in the polymer was determined by the following method. First, 0.1 g of a polymer that has been subjected to post-treatment such as washing and drying was collected, acetonitrile was added, and the total amount was adjusted to 50 mL using a volumetric flask, followed by ultrasonic treatment to disperse the polymer. . This dispersion was filtered through a 0.2 μm membrane filter, and the amount of each unreacted monomer was determined using a high performance liquid chromatograph HPLC-8020 (product name) manufactured by Tosoh Corporation.

In this measurement, a separation column uses one Inertsil ODS-2 (trade name) manufactured by GL Sciences, the mobile phase is a water / acetonitrile gradient system, the flow rate is 0.8 mL / min, and the detector is UV / visible absorption by Tosoh. Measurement was performed using polystyrene as a standard polymer at a photometer UV-8020 (trade name), a detection wavelength of 220 nm, a measurement temperature of 40 ° C., and an injection amount of 4 μL. The separation column Inertsil ODS-2 (trade name) used was a silica gel particle diameter of 5 μm, a column inner diameter of 4.6 mm × column length of 450 mm. The gradient conditions of the mobile phase were as follows, with the liquid A being water and the liquid B being acetonitrile.
Measurement time 0 to 3 minutes: A liquid / B liquid = 90 vol% / 10 vol%
Measurement time 3 to 40 minutes: Liquid A / liquid B = 90% by volume / 10% by volume → 50% by volume / 50% by volume
Measurement time 40 to 62 minutes: A liquid / B liquid = 50 vol% / 50 vol% → 0 vol% / 100 vol%
Measurement time 62-70 minutes: A liquid / B liquid = 0 volume% / 100 volume%

<Specific surface area (nitrogen adsorption method)>
It measured using Nikkiso Co., Ltd. specific surface area measuring apparatus betasorb 4200 type (brand name). About 4 g of a crosslinked polymer was put into a dedicated cell and set in a measuring device, and then degassed at 150 ° C. for 60 minutes, followed by adsorption of nitrogen gas at a liquid nitrogen temperature and measurement of the specific surface area.

<Content of each structural unit>
The content of each constituent unit of the resin for semiconductor lithography was determined by ¹ H-NMR measurement.
The measurement of ¹ H-NMR was performed using a GSX-400 type FT-NMR (trade name) manufactured by JEOL Ltd., and a solution of a polymer sample for semiconductor lithography of about 5% by mass (deuterated dimethyl sulfoxide solution). ) Was placed in a test tube having a diameter of 5 mmφ, and the measurement was performed 64 times in an observation frequency of 400 MHz and a single pulse mode. The measurement temperature was 60 ° C.

<Mass average molecular weight (Mw)>
About 20 mg of resin for semiconductor lithography is dissolved in 5 mL of THF, filtered through a 0.5 μm membrane filter to prepare a sample solution, and this sample solution is measured using a gel permeation chromatography (GPC) manufactured by Tosoh. did. In this measurement, a separation column is manufactured by Showa Denko, Shodex GPC K-805L (trade name) in series, the solvent is THF, the flow rate is 1.0 mL / min, the detector is a differential refractometer, the measurement temperature Measurements were made using polystyrene as the standard polymer at 40 ° C. and an injection volume of 0.1 mL.

<Thermal decomposition temperature (Td)>
About 10 mg of resin for semiconductor lithography was weighed in a dedicated aluminum pan and measured using a TG / DTA6200 thermal analyzer (trade name) manufactured by Seiko Instrument. The temperature elevation condition was measured at 10 ° C./min.

<Glass transition temperature (Tg)>
About 10 mg of resin for semiconductor lithography was weighed in a dedicated aluminum pan and measured using a DSC6200 thermal analyzer (trade name) manufactured by Seiko Instrument. The temperature elevation condition was measured at 10 ° C./min.

Synthesis example 1
In a polymerization apparatus capable of heating and cooling, 200 parts by mass of deionized water and 0.6 parts by mass of polyvinyl alcohol (saponification degree 80%, polymerization degree 1700) are added and stirred to completely remove the polyvinyl alcohol. After dissolution, the stirring is once stopped, and α-methacryloyloxy-γ-butyrolactone represented by the following formula (m1) (hereinafter referred to as GBLMA. SP value is 18.5 (J / cm ³ ) ^1/2 ). 95.0 parts by mass (charged composition ratio: 97.4 mol%) and trimethylolpropane trimethacrylate (hereinafter referred to as TMPTMA) represented by the following formula (m2). SP value is 17.2 (J / cm ³ ) ^1/2 .) 5.0 parts by mass (charge composition ratio: 2.6 mol%) was added and stirring was started again, and 0.5 parts by mass of lauroyl peroxide was added and the temperature was raised to 75 ° C. 75-80 ° C Maintaining the temperature was allowed to react for 3 hours. Thereafter, the reaction solution was further heated to 95 ° C., and this state was maintained for 1 hour to complete the reaction.

After completion of the reaction, the reaction solution was cooled to 50 ° C., 0.3 parts by mass of sodium carbonate was added, and the mixture was stirred for 0.5 hour. Thereafter, the obtained aqueous suspension was filtered through a nylon filter cloth having an opening of 45 μm, washed, and the obtained filtrate was dried at 40 ° C. for about 16 hours to obtain the following formula (A′-1) The granular resin (A'-1) represented by these was obtained.
The polymerization conversion rate of the resin (A′-1) was 99.6%. The specific surface area of the resin (A′-1) measured by the nitrogen adsorption method was 0.07 m ² / g.
The SP value of the resin (A′-1) is 18.5 (J / cm ³ ) ^1/2 for GBLMA, and the SP value for TMPTMA is 17.2 (J / cm ³ ) ^1/2. since it is ^2, GBLMA / TMPTMA = 97.4 SP value of mol% / 2.6 mol% of the polymer, 18.5 × 0.974 + 17.2 × 0.026 = 18.5 (J / cm ³ ) It was ^1/2 .

［ｍ’／ｎ’＝９７．４／２．６（モル比）］

[M ′ / n ′ = 97.4 / 2.6 (molar ratio)]

Next, 200 g of the resin (A′-1) obtained in Synthesis Example 1 and 400 g of γ-butyrolactone (GBL; SP value 18.4 (J / cm ³ ) ^1/2 ) are charged into the container. Stir at 0 ° C. for 3 hours. After the stirring was completed, the resin (A′-1) was swollen by absorbing all γ-butyrolactone.
Next, 600 g of PGMEA was added to the same container, and after stirring (refluxing) with the resin (A′-1) at 80 ° C. for 2 hours, an operation (cleaning treatment) for removing the solvent was performed.
At this time, a small amount of the solvent was collected and analyzed by gas chromatography (GC) to measure the GBL concentration in the solvent. When the above washing treatment (PGMEA addition and solvent removal) was repeated four more times, no GBL was detected from the solvent. The GBL concentration in the solvent after the five washing treatments was 5.8% after the one washing treatment: 0.8% after the two washing treatments: 0.8%, and after the three washing treatments: 0.1%, respectively. After 4 times of washing treatment: 0.04%, after 5 times of washing treatment: ND (less than detection limit).

Next, the operation of adding 400 g of tetrahydrofuran (THF) to the resin (A′-1) and stirring (refluxing) at 60 ° C. for 1 hour to remove the solvent was repeated twice, and then the resin (A′-1) Was dried under reduced pressure for 24 hours to obtain a purified resin (A′-1).
Hereinafter, the purified resin (A′-1) is referred to as resin (A ″ -1).
The resin (A ″ -1) was measured in the same manner as above. As a result, the specific surface area of the resin (A ″ -1) was 0.07 m ² / g. Note that the SP value of the resin (A ″ -1) is the same as the SP value of the resin (A′-1).

[Example 1]
100 g of resin (A ″ -1) was packed into a column (inner diameter: 7 cm, length: 38 cm) using PGMEA.
Next, 2400 parts by mass of PGMEA is added to 1600 parts by mass of a resin solution (PGMEA solution having a solid content concentration of 25% by mass) containing a resin (A-1) represented by the following formula (A-1). A PGMEA resin solution having a concentration of 10% by mass was used.

［ｎ／ｍ／ｌ／ｋ＝３５／３５／１５／１５（モル比）、Ｍｗ＝１００００、Ｍｗ／Ｍｎ＝１．８、Ｍｗ／Ｍｎ＝１．８］

[N / m / l / k = 35/35/15/15 (molar ratio), Mw = 10000, Mw / Mn = 1.8, Mw / Mn = 1.8]

Next, 1000 parts by mass of this PGMEA resin solution was poured into a column filled with the resin (A ″ -1), and the PGMEA resin solution in the column was dropped (eluted) at a flow rate of 3.3 (ml / s). .
The obtained eluate was filtered using a nylon filter (product name: Ultipor N66, manufactured by Pole Corporation) having a pore size of 0.04 μm. The obtained filtrate was concentrated using a rotary evaporator so that the solid content concentration of the resin solution was about 20% by mass. This was designated as Resin Solution 1.

[Example 2]
In Example 1, a resin solution was prepared in the same manner except that the flow rate (elution rate) at which the PGMEA resin solution was dropped was set to 0.38 (ml / s). This was designated as Resin Solution 2.

[Example 3]
In Example 1, a resist resin solution was similarly prepared except that the flow rate (elution rate) at which the PGMEA resin solution was dropped was 0.24 (ml / s). This was designated as Resin Solution 3.

[Comparative Example 1]
In Example 1, a resist resin solution was similarly prepared except that the PGMEA resin solution was not passed through the column. This was designated as Resin Solution 4.

The following evaluation was performed using the obtained resin solutions 1 to 4.
[Defect evaluation]
For each of the resin solutions 1 to 4 obtained in Examples 1 to 3 and Comparative Example 1, 2.0 parts by mass of triphenylsulfonium nonafluorobutane sulfonate, 0.2 parts by mass of triethanolamine, and 900 parts by mass of PGMEA Part, 25 parts by mass of γ-butyrolactone and 0.1 part by mass of a surfactant (product name: R-08, manufactured by Dainippon Ink & Chemicals, Inc.) were dissolved, and the solution was dissolved with a pore size of 0.04 μm. Filter in the order of nylon filter (product name: Urpotia N66, manufactured by Pall Co., Ltd.) and polypropylene filter (product name: unipore polyfix, manufactured by Kitz) in the order of 0.02 μm, and positive resist composition solution 1 ~ 4 were prepared.

Next, an organic antireflection film material (product name: ARC-29A, manufactured by Brewer Science) is applied onto an 8-inch silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 77 nm. To form a substrate.
On the substrate, the positive resist composition solution obtained above is uniformly applied using a spinner, pre-baked on a hot plate at 120 ° C. for 90 seconds, and dried to obtain a resist having a film thickness of 250 nm. A layer was formed.
Next, an ArF excimer laser (193 nm) was applied to the mask pattern using an ArF exposure apparatus (wavelength 193 nm) NSR-S306 (product name, manufactured by Nikon, NA (numerical aperture) = 0.78, 2/3 annular illumination). Via selective exposure.
Then, PEB treatment was performed at 120 ° C. for 90 seconds, and further developed with a developer (2.38 mass% tetramethylammonium hydroxide aqueous solution) at 23 ° C. for 60 seconds. Thereafter, water was used for 15 seconds with pure water. Rinse and shake-dry. Thereafter, the film was dried by heating at 100 ° C. for 90 seconds to form a line-and-space resist pattern (L / S pattern) having a line width of 120 nm and a pitch of 240 nm.
Next, the surface defect observation apparatus KLA2351 (product name) manufactured by KLA Tencor was used to observe the L / S pattern surface, and the total number of all defects in the wafer and the number of bridge mode defects were obtained. The results are shown in Table 1.

[Contact Impact Assessment]
The resin solutions 1 to 4 and the PGMEA resin solution before passing through the column were analyzed by GPC and NMR.
As a result, it was confirmed that all the GPCs had peaks at the same position and had almost no influence on the molecular weight distribution by passing through the column. Moreover, the result of NMR was also the same and there was almost no difference in a peak.
Moreover, as a result of measuring thermal decomposition temperature Td and glass transition temperature Tg about these resin solutions, all had equivalent Td and Tg.

[Lithography characteristics evaluation]
An L / S pattern having a line width of 100 nm and a pitch of 200 nm was formed in the same manner as the defect evaluation.
When the obtained L / S pattern was observed with a scanning electron microscope (SEM), the pattern was formed in a good shape in any of the examples.
Further, the optimum exposure amount Eop (mJ / cm ² ) at which the L / S pattern is formed and the depth of focus (in the above Eop, the focus is appropriately shifted up and down, and the L / S pattern is 100 nm ± 10%. When the depth of focus (DOF) width (μm) obtained within the range of the dimensional change rate was determined, all were almost equal.

As shown in the above results, the resist pattern surface formed using the positive resist compositions 1 to 3 obtained using the resin solutions 1 to 3 passed through the column filled with the resin (A ″ -1). The number of defects was reduced both in the total number of defects and the number of bridge mode defects, in particular, the bridge mode defects were greatly reduced, and the lithography characteristics were also good.
In addition, when comparing the positive resist compositions 1 to 3, the total number of defects tends to decrease as the elution rate of the PGMEA resin solution increases, but the number of bridge mode defects greatly decreases regardless of the elution rate. It had been.
Furthermore, these positive resist compositions were also excellent in various lithography properties such as resolution, resist pattern shape, sensitivity, and DOF.
On the other hand, in Comparative Example 1 using the positive resist composition 4 obtained using the resin solution 4 not passed through the column, the total number of defects and the number of bridge mode defects were very large.
From these results, it is clear that the resin (A ″ -1) produced by the production method of the present invention is suitable for semiconductor lithography.

It is the schematic for demonstrating the method used suitably when making a resin solution (R1) and resin (A1 ') contact.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Resin (A1 '), 3 ... Filter, 4 ... Filter.

Claims (3)

A resin solution (R1) in which a resin for semiconductor lithography (A1) containing a structural unit (a2) having a lactone-containing cyclic group is dissolved in an organic solvent (S1) has a solubility parameter of 17 to 20 (J / cm ³ ). ^A method for producing a resin for semiconductor lithography, comprising contacting a resin (A1 ′) having a ^half surface area and a specific surface area of 0.005 to ¹ m ² / g.   The method for producing a resin for semiconductor lithography according to claim 1, wherein the resin (A1 ') contains a structural unit (a2') having a lactone-containing cyclic group.   The method for producing a resin for semiconductor lithography according to claim 1 or 2, wherein the resin for semiconductor lithography (A1) contains a structural unit (a1) containing an acid dissociable, dissolution inhibiting group.

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