JP2012207217A - Method of producing resin for resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method capable of obtaining a resin for a resist composition at a high yield.SOLUTION: The present invention discloses the method of producing the resin for the resist composition, capable of polymerizing a monomer in a mixed solvent mixed with a solvent (1) and a solvent (2), wherein the solvent (1) has a solubility parameter within a range of 11.4-13.0 [cal/mol], and a solvent (2) is tetrahydrofuran. The monomer is preferably polymerized by an action of a polymerization initiator, in the production method, and the monomer is preferably polymerized by dropping a mixture liquid containing the monomer, the polymerization initiator and the solvent (2), into the solvent (1).

Description

  The present invention relates to a method for producing a resin for a resist composition.

  The chemically amplified resist composition includes a resin having an acid labile group (resin for resist composition).

  As a method for producing such a resin for a resist composition, for example, a monomer mixture is prepared by preparing a mixed solution comprising a monomer for producing the resin, a polymerization initiator and ethyl lactate, and dropping the mixed solution into ethyl lactate. A method of polymerizing is known (see Patent Document 1).

International Publication No. 2006/028071

  In the conventional manufacturing method, the yield of the resin for resist composition obtained may not necessarily be fully satisfied.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ２は０〜３の整数を表す。］ The present invention includes the following inventions.
[1] A method for producing a resin for a resist composition, comprising a step of polymerizing monomers in a mixed solvent containing a solvent (1) and a solvent (2).
Solvent (1): Solubility parameter is 11.4 to 13.0 [cal / mol] ^1/2
A solvent that is within the range of
Solvent (2): Tetrahydrofuran [2]
[1] The method for producing a resin for a resist composition according to [1], wherein the monomer is polymerized by the action of a polymerization initiator.
[3]
Preparing a mixed solution comprising at least a part of the monomer, at least a part of the solvent (2), and a polymerization initiator;
The method for producing a resin for a resist composition according to [1], further comprising a step of dropping the mixed solution into the solvent (1).
[4] The method for producing a resin for a resist composition according to any one of [1] to [3], wherein the mixed solvent substantially comprises the solvent (1) and the solvent (2).
[5] The method for producing a resin for a resist composition according to any one of [1] to [4], wherein the monomer includes a monomer having an acid labile group.
[6] The method for producing a resin for a resist composition according to [5], wherein the monomer having an acid labile group is a monomer represented by formula (a1-1) or formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent a group represented by —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents − Represents a bond with CO-.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n2 represents an integer of 0 to 3. ]

  According to the present invention, a resin for a resist composition can be obtained in high yield.

  As described above, the method for producing a resin for a resist composition of the present invention (hereinafter, abbreviated as “resin” in some cases) is the solvent (1) and the solvent (2) as described above. And a step of polymerizing the monomer in the mixed solvent. First, the solvent (1) and the solvent (2) will be described.

The solvent (1) has a solubility parameter in the range of 11.4 to 13.0 [cal / mol] ^1/2 and has a liquid form in the temperature range of 0 ° C. to the reaction temperature of this production method. It is shown.
The solubility parameter is a numerical value calculated by the following calculation formula. The numerical value is, for example, “IUPAC Gold Book-solubility parameter, δ” or solvent handbook (1963, published by Sangyo Tosho Co., Ltd., Matsuda Tanemitsu, Hakoshima Masaru , Written by Tomoyuki Kamakari).
δ = (ΔH−RT / V) ^1/2
[Where:
δ represents the solubility parameter, ΔH represents the heat of molar evaporation, R represents the gas constant, T represents the temperature, and V represents the molar volume. ]

The solvent (1) can be selected from commonly available solvents by determining the solubility parameter by the above calculation formula or by determining the solubility parameter from the numerical values described in the above publications. ) Preferably has a higher boiling point under atmospheric pressure than tetrahydrofuran, which is the solvent (2). Examples of such a solvent (1) include acetonitrile (12.11), N, N-dimethylformamide (12.1), dimethyl sulfoxide (12.0), ethanol (12.8), γ-butyrolactone (12. 8), ethyl lactate (11.6), cyclohexanol (11.4) and the like. In the specific example of the solvent (1), the numerical value in parentheses is a numerical value indicating the solubility parameter [cal / mol] ^1/2 .

The solvent (2) is tetrahydrofuran, and its solubility parameter is 9.9 [cal / mol] ^1/2 .

  The mixed solvent used in this production method includes the solvent (1) and the solvent (2), and the mixing ratio is arbitrary. The mixing weight ratio of the solvent (1) and the solvent (2) is [solvent ( 1)]: [Solvent (2)], for example, can be selected from a range of 99: 1 to 1:99. As described above, the solvent (1) has a higher boiling point than the solvent (2). In some cases, it is preferable that the amount of the solvent (1) used is larger than the amount of the solvent (2) because a resin can be obtained with a higher yield. 99: 1 to 70:30, more preferably 95: 5 to 80:20.

  The mixed solvent may contain a small amount of a solvent other than the solvent (1) and the solvent (2), but is preferably substantially composed of the solvent (1) and the solvent (2). The “mixed solvent substantially consisting of the solvent (1) and the solvent (2)” here means that, for example, water and the like that are unintentionally contained can be contained in a small amount.

  The total amount of the mixed solvent is, for example, in the range of 30 to 700% by weight, and preferably in the range of 50 to 300% by weight, based on the total weight of all monomers used in the production method.

  This production method is preferably solution polymerization in which the monomer is polymerized in the mixed solvent, and the monomer is polymerized in the mixed solvent by the action of a polymerization initiator. Such polymerization is more preferably radical polymerization in that it can be carried out on a commercial scale. When the polymerization is radical polymerization, a chain transfer agent can be used as necessary. Hereinafter, the case where the polymerization in this production method is solution polymerization and radical polymerization will be mainly described.

The solution polymerization in this production method is
A batch polymerization method in which the monomer is dissolved in a solvent to form a mixture, and then the resulting mixture is heated to a predetermined polymerization temperature;
An initiator addition method in which the monomer is dissolved in a solvent to form a mixture, and the resulting mixture is kept at a predetermined polymerization temperature, and a polymerization initiator is added to the mixture that has reached the predetermined polymerization temperature;
At least a part of the monomer is dropped into the solvent kept at a predetermined polymerization temperature, or a mixed liquid obtained by mixing at least a part of the monomer and at least a part of the solvent is kept at a predetermined polymerization temperature. It can carry out by any of the dropping polymerization method etc. which dripped the said liquid mixture in the remainder of the said solvent. In addition, the solvent used for the batch polymerization method shown here, the initiator addition method, or the dropping polymerization method is the said mixed solvent. In the batch polymerization method, a polymerization initiator and a chain transfer agent used as necessary may be dissolved in a solvent together with monomers. In the batch polymerization method, a polymerization initiator or the like may be added together with the monomer to the remainder of the solvent kept at a predetermined polymerization temperature, and at least a part of the polymerization initiator is kept at a predetermined polymerization temperature in advance. You may make it melt | dissolve in the remainder of the said solvent.

  Of these, the drop polymerization method is preferred because a resin having a narrow composition distribution or a resin having a narrow molecular weight distribution can be easily obtained. As described above, in the dropping polymerization method, even if the monomer is dropped into a solvent kept at a predetermined polymerization temperature, a solution prepared by dissolving the monomer in the solvent in advance is prepared (hereinafter referred to as the case). (Hereinafter referred to as “dropping solution”), and then the dropping solution may be dropped into the remainder of the solvent kept at a predetermined polymerization temperature, but the latter is preferred. For example, after adding a solvent (hereinafter, referred to as “charged solvent” in some cases) to a polymerization vessel in advance and heating to a predetermined polymerization temperature, a monomer and a polymerization initiator are each prepared as a drop solution prepared independently or in any combination. May be dropped into the charged solvent, a solution in which the polymerization initiator is dissolved in the monomer may be dropped into the charged solvent, or a solution in which the polymerization initiator and the monomer are dissolved in the solvent is dropped into the charged solvent. May be.

  When a solvent is used for the preparation of the dropping solution, the monomer concentration is 5 to 70% by weight depending on the type of the monomer so that the monomer does not phase-separate or precipitate the monomer in the dropping solution. It is chosen from the range. Similarly, the concentration of the polymerization initiator in the dropping solution containing the polymerization initiator is determined depending on the type of the polymerization initiator so that the polymerization initiator does not phase-separate or precipitate in the dropping solution. Accordingly, it is selected from the range of 5 to 60% by weight. Even when the dropping solution is a monomer and a polymerization initiator combined and dissolved in a solvent, each is selected from the concentration range shown here. In addition, when a solvent is used for preparing the dropping solution, the amount of the charged solvent is the remaining amount obtained by subtracting the amount of the solvent used for preparing the dropping solution from the total amount of the solvent already described. The amount is selected according to the type of stirrer provided in the polymerization vessel so that the amount can be stirred in the polymerization vessel.

  There is no particular limitation on the dropping time for dropping the dropping solution in the charged solvent, but if the dropping time is too short, the composition distribution of the resin produced at the initial stage of polymerization tends to be widened, and the resin obtained finally Since the molecular weight tends to increase, the dropping time is preferably 1 hour or longer. Moreover, since the productivity of resin will be impaired when dripping time is too long, 5 hours or less are preferable for dripping time. In addition, when the dropping solution containing a monomer and the dropping solution containing a polymerization initiator are prepared separately and these dropping solutions are dropped separately in a charged solvent, the dropping time referred to here is a dropping solution containing a monomer. The time from the start of dropping to the end of dropping.

  In the dropping polymerization method, after the dropping of the dropping solution into the charged solvent is completed, the mixture after dropping is further stirred for a predetermined time, preferably 1 to 10 hours, more preferably 2 to 8 hours. By maintaining the temperature at the polymerization temperature, the polymerization reaction is completed. The time for keeping the mixture after dropping at a predetermined polymerization temperature can be determined, for example, by appropriately sampling the reaction mixture during the reaction and tracking the molecular weight of the produced resin and the disappearance degree of the used monomer. The polymerization temperature when keeping the mixture after dropping is allowed to have an error of about ± 2 ° C. from the predetermined polymerization temperature, and the heating means of the polymerization vessel is controlled so as to maintain this temperature error. It is preferable.

  When the production method produces a resin by radical polymerization, it is preferable to use a polymerization initiator as described above. The polymerization initiator is selected from general-purpose radical generators according to the type of monomer used in the production method. For example, 2,2′-azobisisobutyronitrile, dimethyl-2,2 Azo compounds such as' -azobisisobutyrate, 2,2'-azobis [2- (2-imidazolin-2-yl) propane]; 2,5-dimethyl-2,5-bis (tert-butylperoxy) ) Organic peroxides such as hexane can be mentioned. In addition, a polymerization initiator may be used independently or may be used in mixture of multiple types. Furthermore, in consideration of the point where the polymerization is likely to proceed at an appropriate polymerization rate, the polymerization initiator used preferably has a 10-hour half-life temperature of 50 ° C. or higher.

  The amount of polymerization initiator used is appropriately selected depending on the type, monomer, type of chain transfer agent used as needed, and production conditions such as polymerization temperature. For example, the total use of all monomers The range of 0.3-12.0 mol% is preferable with respect to the amount, and the range of 1.0-10.0 mol% is more preferable.

  The polymerization temperature is, for example, in the range of 50 to 150 ° C, preferably in the range of 60 to 120 ° C. It is preferable to select the type and the like of the polymerization initiator used and the solvent (1) so that the polymerization temperature falls within the above range. In addition, although the temperature at the time of dripping the said dripping solution to the said preparation solvent and the temperature which stirs the mixture after dripping solution dripping may be comparable or different, both temperature may be chosen from the said range. preferable.

One of the dropping solution and the charging solvent in the dropping polymerization is a part of the mixed solution, and the other is the rest of the mixed solution. Among the mixed solvents, at least a part of the solvent (1) is used as the charging solvent. It is preferable to use at least a part of the solvent (2) for preparing the dropping solvent. In this case, the process of the present production method comprises a step of preparing a dropping solution by dissolving the monomer and the polymerization initiator in the solvent (2), and a step of dropping the dropping solution into the solvent [solvent (1)]. And have.
Further, when at least a part of the solvent (2) is used for preparing the dropping solution in this way, the present inventor, for example, prepares the dropping solution by dissolving the preferable monomer and the solvent (2) described later. It has also been found that the preparation time is relatively short.

  Moreover, even when the solvent used for the said dripping solution preparation is at least one part of the solvent (2), it is preferable that the solvent (1) is further included in the solvent used for this dripping solution preparation. That is, it is preferable that the dropping solution prepared by dissolving the monomer and / or the polymerization initiator in the solvent (2) further contains the solvent (1). As already described, since the mixed solution used in the present production method is preferably used in a larger amount of the solvent (1) than the solvent (2), the solvent (2) is also used in the preparation of the dropping solution. In addition, it is desirable to use a solvent (1). When the solvent (1) and the solvent (2) are combined and used for preparing the dropping solution, the mixing weight ratio of the solvent (1) to the solvent (2) in the dropping solution is [solvent (1)] / [solvent ( 2)], 60/40 to 99/1 are preferable, and 75/15 to 95/5 are particularly preferable.

  When a chain transfer agent is used in the dropping polymerization method, the chain transfer agent may be dissolved in a preparation solvent or a dropping solution, but is preferably dissolved in a dropping solution. Examples of the chain transfer agent include known thiol compounds such as dodecyl mercaptan, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid, and 4,4-bis (trifluoromethyl) -4-hydroxy-1-mercaptobutane. Can be mentioned. The chain transfer agent can be used alone or in combination. The amount of chain transfer agent used can be appropriately selected depending on the type, the type of monomer and polymerization initiator used, the production conditions such as the polymerization temperature. Further, the amount of the chain transfer agent used can be determined so that a resin having a desired molecular weight can be obtained.

  The reaction mixture after polymerization is preferably cooled, diluted with an appropriate solvent, or a combination thereof to stop the progress of the polymerization reaction. The solvent used for diluting the reaction mixture (hereinafter sometimes referred to as “diluting solvent”) is preferably selected from “good solvents” (good solvents) that can sufficiently dissolve the produced resin. Examples of good solvents in the case of obtaining a resin using 1,4-dioxane, acetone, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, γ-butyrolactone, propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether it can. The amount of the dilution solvent used is preferably determined so that the diluted reaction mixture has an appropriate solution viscosity. The cooled and / or diluted reaction mixture is preferably mixed with a “poor solvent” (poor solvent) in which the resulting resin is insoluble or sparingly soluble, and the resulting resin is precipitated from the reaction mixture in solid form. Preferably, a solution obtained by diluting the reaction mixture with a diluting solvent is dropped into a large amount of a poor solvent to precipitate the produced resin in a solid state. The resin precipitation method using such a good solvent and a poor solvent can sufficiently remove unreacted substances such as monomers and polymerization initiator used in the polymerization from the resulting resin by selecting an appropriate combination.

  When the progress of the polymerization reaction is stopped by cooling the reaction mixture after polymerization, the cooling temperature is preferably 35 ° C. or more lower than the polymerization temperature, more preferably in the range of 0 to 40 ° C., 0 More preferably, it is in the range of -30 ° C. Within this temperature range, the progress of the polymerization reaction can be sufficiently suppressed.

  As the poor solvent, an appropriate one can be selected from those insoluble or hardly soluble depending on the type of resin produced, but as a poor solvent when a resin is obtained using a preferable monomer described later, Examples thereof include water; alcohols such as methanol and isopropanol; saturated hydrocarbons such as hexane and heptane, and mixed solvents thereof. The resin precipitated from the reaction mixture is separated from the reaction mixture by a general solid-liquid separation operation such as filtration. If necessary, the separated resin can be washed with an appropriate washing solvent (preferably a poor solvent) and then sufficiently dried, for example, to obtain the resin as a dry powder. If necessary, after washing with a washing solvent, the resin can be dissolved in a solvent that can dissolve the resin to obtain a resin solution. Since the resin obtained by this production method is for a resist composition, if the resin solution is prepared with a solvent used for preparing the resist composition, the resin solution can be used for preparing the resist composition. It becomes easier. In addition, you may add suitably additives, such as a suitable storage stabilizer, to this resin solution.

  As mentioned above, although this manufacturing method was demonstrated centering on the preferable aspect which is solution polymerization and radical polymerization, the preferable monomer used for this this manufacturing method is demonstrated continuously.

  As the monomer, a known monomer that gives a structural unit constituting a resin for a resist composition can be mentioned. When the resist composition is a chemically amplified resist composition, a monomer having an acid labile group is used. It is done. As the monomer having such an acid labile group, for example, monomers represented by formula (a1-1) and formula (a1-2) are preferable.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−で表される基を表し、ｋ１は１〜７の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ２は０〜３の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent a group represented by —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents − Represents a bond with CO-.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n2 represents an integer of 0 to 3. ]

L ^a1 and L ^a2 are preferably —O— or a group represented by ^* —O— (CH ₂ ) _k1 —CO—O—, wherein k1 is in the range of 1 to 4, more preferably — O— or ^* —O—CH ₂ —CO—O—, more preferably —O—.
R ^a4 and R ^a5 are preferably methyl groups.
^Examples of the alkyl group for R ^a6 and R ^a7 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms. The alicyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 6 or less.

ｍ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１は、好ましくは０〜３の整数、より好ましくは０又は１である。 The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, Examples thereof include cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.

m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.

If a resin is obtained by this production method using the monomer represented by formula (a1-1) or formula (a1-2), the introduction rate of structural units derived from these monomers with respect to the total amount of structural units of the resin is determined. Can be high. In addition, when this manufacturing method is performed using the monomer represented by Formula (a1-1) and / or the monomer represented by Formula (a1-2) with the introduction rate here, among these monomers The ratio of the amount used in this production reaction (the amount used) to the amount consumed for resin formation of these monomers. According to this production method, particularly this production method using radical polymerization, it becomes very easy to control the composition ratio of structural units derived from these monomers in the resin by the amount of the monomer used. The composition ratio of structural units derived from these monomers in the obtained resin is, for example, subjecting the resin to ¹ H-NMR measurement or ¹³ C-NMR measurement, or the amount of unreacted monomer remaining at the end of polymerization as gas. It can be determined by calculating the amount of monomer consumed for resin formation, measured by chromatography analysis or liquid chromatography analysis. The monomers represented by the formula (a1-1) and the formula (a1-2) can introduce a bulky skeleton into the resin, and thus can produce a resin that can form a resist pattern with better dry etching resistance, Due to the steric hindrance, when the resin is produced by radical polymerization, the introduction rate tends to be low. According to this production method, there is an advantage that a resin can be produced from the monomers represented by formula (a1-1) and formula (a1-2) at a high introduction rate, and the effects of the present invention can be further enjoyed. .

［式（ａ１−ａ）及び式（ａ１−ｂ）中、
Ｒ^a4〜Ｒ^a7、ｍ１、ｎ１及びｎ２は、式（ａ１−１）又は式（ａ１−２）と同じ意味を表す。］ Monomers represented by the following formulas (a1-a) and (a1-b) are particularly preferable in that the composition ratio of structural units derived from monomers in the resin can be more easily controlled.

[In the formulas (a1-a) and (a1-b),
R ^{a4 to} R ^a7 , m1, n1 and n2 represent the same meaning as in formula (a1-1) or formula (a1-2). ]

Examples of the monomer represented by the formula (a1-1) include monomers described in JP 2010-204646 A. Among these, monomers represented by formulas (a1-1-1) to (a1-1-7) are preferable, and monomers represented by formulas (a1-1-1) to (a1-1-3) are preferable. More preferred.

Examples of the monomer represented by the formula (a1-2) include 1-ethyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 1-ethyl-1-cycloheptyl (meta ) Acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, 1-isopropyl-1-cyclopentyl (meth) acrylate, and the like. As the monomer represented by the formula (a1-2), monomers represented by the formulas (a1-2-1) to (a1-2-6) are preferable, and the formulas (a1-2-3) to (a1) are preferable. The monomer represented by -2-4) is more preferable, and the monomer represented by the formula (a1-2-3) is more preferable.

  In this production method, when using the monomer represented by the formula (a1-1) and / or the monomer represented by the formula (a1-2), the total use amount of these monomers is based on the total use amount of the monomers. The range of 10 to 95 mol% is preferable, the range of 15 to 90 mol% is more preferable, and the range of 20 to 85 mol% is more preferable. If it is in the said range, the resin obtained for a resist composition will be obtained. As already described, since this production method can increase the introduction rate of these monomers, the monomer represented by the formula (a1-1) and the formula (a1- The structure derived from the monomer represented by the formula (a1-1) and the monomer represented by the formula (a1-2) in the obtained resin by controlling the total amount of the monomer represented by 2) The unit content can be set to a desired range. That is, the total content of the structural unit derived from the monomer represented by the formula (a1-1) and the structural unit derived from the monomer represented by the formula (a1-2) with respect to all the structural units of the resin, By controlling the ratio of the total use amount of these monomers to the total use amount of all monomers, it becomes possible to easily obtain a resin having a desired content.

  In addition to the monomer having an acid labile group, the resin obtained by this production method can also use a monomer having no acid labile group (hereinafter sometimes referred to as “acid-stable monomer”).

［式（ａ２−０）中、
Ｒ^a30は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一であっても異なってもよい。］ As an acid stable monomer, the monomer represented by a formula (a2-0) is mentioned, for example.

[In the formula (a2-0),
R ^a30 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same or different. ]

Specific examples of the alkyl group in R ^a30 are the same as those described for R ^a6 in formula (a1-1) as long as the number of carbon atoms is 6 or less, and at least one of the hydrogen atoms contained in these alkyl groups. A group in which a part is substituted with a halogen atom corresponds to an alkyl group having a halogen atom. The alkyl group for R ^a30 is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
Examples of the alkoxy group in R ^a31 include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. Preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group and an ethoxy group, and particularly preferably a methoxy group.
^Examples of the acyl group in R ^a31 include an acetyl group and a propoxy group. A group in which —O— is further bonded to this acyl group corresponds to an acyloxy group.
ma is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.

Examples of the monomer represented by the formula (a2-0) include monomers described in JP 2010-204634 A, and each of the monomers represented by the formulas (a2-0-1) and (a2-0-2) The monomers represented are preferred. When the resin is produced, those obtained by protecting the phenolic hydroxyl group in these with an appropriate protecting group can also be used.

  When the monomer represented by the formula (a2-0) is used in this production method, the content of the structural unit derived from the monomer represented by the formula (a2-0) with respect to all structural units of the obtained resin is 5 The range of -90 mol% is preferable, the range of 10-85 mol% is more preferable, and the range of 15-80 mol% is further more preferable. This production method includes the composition ratios of the structural units derived from the monomers represented by the formula (a1-1) and the formula (a1-2), respectively, and the formula (a1-1) and the formula (a1-2), respectively. Although it has been explained that the introduction ratio of the monomer represented can be increased, the same effect can be obtained for the monomer represented by the formula (a2-0).

［式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−で表される基を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。］ As the acid stable monomer, a monomer represented by the formula (a2-1) can also be used.

[In the formula (a2-1),
L ^a3 represents a group represented by —O— or ^* —O— (CH ₂ ) _k2 —CO—O—.
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10. ]

In the formula (a2-1), L ^a3 is preferably, -O- -O- or k2 is in the range of _{1~4 (CH 2) k2 -CO-} O- , a group represented by the more -O- is preferable.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer represented by the formula (a2-1) include monomers described in JP 2010-204646 A. Especially, the monomer respectively represented by Formula (a2-1-1)-Formula (a2-1-6) is preferable, and each is represented by Formula (a2-1-1)-Formula (a2-1-4). A monomer is more preferable, and a monomer represented by formula (a2-1-1) or formula (a2-1-3) is more preferable.

  When the monomer represented by the formula (a2-1) is used in this production method, the content of the structural unit derived from the monomer represented by the formula (a2-1) with respect to all structural units of the obtained resin is 3 The range of -40 mol% is preferable, the range of 5-35 mol% is more preferable, and the range of 5-30 mol% is further more preferable.

  As the acid stable monomer, monomers represented by the formula (a3-1), the formula (a3-2), and the formula (a3-3) can also be used.

［式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−で表される基を表し、ｋ３は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、炭素数１〜４のアルキル基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４のアルキル基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１が２以上のとき、複数のＲ^a21は、互いに同一でも異なってもよく、ｑ１が２以上のとき、複数のＲ^a2３は、互いに同一でも異なってもよく、ｒ１が２以上のとき、複数のＲ^a23は、互いに同一でも異なってもよい。］

[In Formula (a3-1)-Formula (a3-3),
L ^{a4 to} L ^a6 each independently represent a group represented by —O— or ^* —O— (CH ₂ ) _k3 —CO—O—, and k3 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an alkyl group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an alkyl group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1 is 2 or more, a plurality of R ^a21 may be the same or different from each other. When q1 is 2 or more, a plurality of R ^a23 may be the same or different from each other. R ^a23 may be the same as or different from each other. ]

Examples of L ^{a4 to} L ^a6 include those described for L ^a3 .
L ^{a4 to} L ^a6 are each independently preferably —O— or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— in which k3 is in the range of 1 to 4; -Or ^* -O-CH ₂ -CO-O- is more preferable, and -O- is more preferable.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

Examples of the monomer represented by each of the formula (a3-1), the formula (a3-2), and the formula (a3-3) include monomers described in JP 2010-204646 A. Among them, formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4), formula (a3-3-1) to formula (a3) -3-4) is preferable, and each of the monomers represented by formulas (a3-1-1) to (a3-1-2) and (a3-2-3) to (a3-2-4) is preferable. The monomer represented is more preferable, and the monomer represented by the formula (a3-1-1) or (a3-2-3) is more preferable.

  When a monomer represented by any one of formula (a3-1), formula (a3-2) or formula (a3-3) is used in this production method, it is derived from these monomers with respect to all structural units of the resulting resin. The total content of the structural units is preferably in the range of 5 to 50 mol%, more preferably in the range of 10 to 45 mol%, and still more preferably in the range of 15 to 40 mol%.

  The weight average molecular weight of the resin obtained by this production method is preferably 1,000 or more and 100,000 or less, more preferably 2,000 or more and 50,000 or less, and further preferably 2,500 or more and 30,000. It is as follows. When the weight average molecular weight of the resin is within the above range, the resin composition is sufficiently soluble in the solvent for preparing the resist composition, so that the resist composition can be easily prepared. In addition, a weight average molecular weight can be calculated | required in conversion of the molecular weight of a standard polystyrene by GPC method, for example.

  By using the monomer having an acid labile group and the acid stable monomer exemplified above, this production method can produce a resin with higher yield. The yield is, for example, 50% or more, preferably 60% or more, and more preferably 70% or more. In addition, the yield here is calculated | required by the ratio of the weight of the obtained resin with respect to the total use weight of all the monomers.

For example, the resin obtained from this production method using the monomer represented by the formula (a1-1) or the formula (a1-2) has a degree of dispersion (weight average molecular weight determined by the GPC analysis and a number The molecular weight dispersity calculated from the average molecular weight is extremely narrow, and is preferable as a resin for resist compositions.
The degree of dispersion of the resin is in the range of 1.0 to 5.0, preferably in the range of 1.0 to 3.0, more preferably in the range of 1.2 to 2.5. This manufacturing method enables easy manufacturing.

  In addition, since the resin obtained by this production method can increase the yield per unit polymerization time compared to the conventional method, for example, the polymerization time is shorter than the conventional production method to obtain the desired yield. There is an effect that. Therefore, it can be said that this production method has high productivity in the commercial production of the resin for resist compositions. In other words, if the polymerization time is a predetermined value, it can be said that the present production method yields a larger amount of the resin for the resist composition than the conventional production method.

  The resin obtained by this production method is preferably used for a resist composition. The resist composition contains an acid generator and a solvent in addition to the resin obtained by this production method, and usually a resin obtained by this production method, an acid generator, and a solvent are mixed. It is prepared by. In addition to these resins, acid generators and solvents, basic compounds may be mixed as necessary. In such preparation, the mixing order of the resins and the like is arbitrary and is not particularly limited. The temperature at the time of mixing can select a suitable temperature range from the range of 10-40 degreeC according to the kind etc. of resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used. Further, as already described, in this production method, the produced resin can also be obtained in the form of a resin solution in which a resist composition preparation solvent is dissolved. Can be prepared.

The resist composition thus obtained is used for producing a resist pattern well known in the resist field. Such resist pattern manufacturing is, for example,
(1) A resist composition is applied on a substrate,
(2) The composition after coating is dried to form a composition layer,
(3) exposing the composition layer;
(4) heating the composition layer after exposure;
(5) developing the composition layer after heating;
It consists of the operation.

  The resist composition containing a resin obtained by this production method is suitable as a resist composition for KrF excimer laser exposure, ArF excimer laser exposure, EB, or EUV exposure.

Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. The weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were determined by gel permeation chromatography using polystyrene as a standard product (HLC-8120GPC manufactured by Tosoh, column: Multipore HXL-M manufactured by Tosoh). Asked.
The structural unit composition of the resin was determined from ¹³ C-NMR (MR-400 FT-NMR manufactured by Varian Technologies, Inc., measurement solvent: deuterated chloroform, measurement temperature: 35 ° C.). The introduction rate of the structural unit derived from the monomer is determined by high-performance liquid chromatography (apparatus: LC-2010HT manufactured by Shimadzu Corporation, column: YMC Pack C4 (trade name) manufactured by YMC) for each monomer. The amount of monomer consumed for resin formation was calculated by subtracting from the amount of monomer used for resin production and calculated from the ratio thereof.

なお、以下の実施例等において、モノマーＡ由来の構造単位等を、そのモノマー符号に合わせて、「Ａ」等という。 The monomers used in the examples are shown below.

In the following examples and the like, the structural unit derived from the monomer A is referred to as “A” or the like in accordance with the monomer code.

Example 1 (Production of Resin A1 by Drop Polymerization of this Production Method)
Monomer A 25.00 parts, Monomer B 2.95 parts, Monomer C 2.73 parts, Monomer D 7.69 parts, Azobisisobutyronitrile 0.24 parts, Azobis-2,4-dimethylvaleronitrile 08 parts, 25.78 parts of γ-butyrolactone, and 3.00 parts of tetrahydrofuran were mixed to prepare a solution (drop solution). In the preparation of such a dropping solution, the solution was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time taken for dissolution (preparation time) was 51 minutes.
In a four-necked flask equipped with a dropping device, a thermometer and a reflux tube, 9.59 parts of γ-butyrolactone (prepared solvent) was charged in a nitrogen atmosphere, and the temperature was raised to about 73 ° C. while stirring. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 73 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 73 ° C.
The reaction mixture was cooled to about room temperature and diluted with 61.39 parts of tetrahydrofuran. The diluted reaction mixture was poured into 536 parts of a mixed solvent of water and methanol (water: methanol (weight ratio) = 2: 8) with stirring, and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 249 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 28.9 parts resin A1.
Yield: 75.2%
Mw: 7.8 × 10 ³ , Mw / Mn: 1.79,
Structural unit composition ratio in resin A1: A / B / C / D = 60/8/10/22

Example 2 (Production of Resin A2 by Drop Polymerization of this Production Method)
Monomer A 25.00 parts, Monomer B 2.95 parts, Monomer C 2.73 parts, Monomer D 7.69 parts, Azobisisobutyronitrile 0.24 parts, Azobis-2,4-dimethylvaleronitrile 1. 08 parts, 28.78 parts of cyclohexanol, and 10.00 parts of tetrahydrofuran were mixed to prepare a solution (drop solution). In the preparation of such a dropping solution, the solution was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time taken for dissolution (preparation time) was 45 minutes.
In a four-necked flask equipped with a dropping device, a thermometer, and a reflux tube, 9.59 parts of cyclohexanol (prepared solvent) was charged and bubbled with nitrogen gas for 30 minutes. This charged solvent was heated to about 73 ° C. under a nitrogen seal. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 73 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 73 ° C.
The reaction mixture was cooled to about room temperature and diluted with 61.39 parts of tetrahydrofuran. The diluted reaction mixture was poured into 536 parts of a mixed solvent of water and methanol (water: methanol (weight ratio) = 2: 8) with stirring, and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 249 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 26.6 parts of resin A2.
Yield: 69.3%
Mw: 12.2 × 10 ³ , Mw / Mn: 2.09
Structural unit composition ratio in resin A2: A / B / C / D = 56/10/11/24

Example 3 (Production of Resin A3 by Drop Polymerization of this Production Method)
The same experiment as in Example 1 was performed except that acetonitrile was used instead of γ-butyrolactone as a charging solvent to obtain 26.9 parts of resin A3 (however, in the preparation of the dropping solution, the monomers and the like were completely removed). The time until dissolution (preparation time) was 47 minutes).
Yield: 70.2%
Mw: 5.8 × 10 ³ , Mw / Mn: 1.72
Structural unit composition ratio in resin A3: A / B / C / D = 58/9/9/24

Example 4 (Production of Resin A4 by Drop Polymerization in this Production Method)
Monomer A 25.00 parts, Monomer B 2.95 parts, Monomer C 2.73 parts, Monomer D 7.69 parts, Azobisisobutyronitrile 0.24 parts, Azobis-2,4-dimethylvaleronitrile 1. 08 parts, ethyl lactate 25.21 parts, and tetrahydrofuran 3.68 parts were mixed to prepare a solution (drop solution). In the preparation of such a dropping solution, the solution was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time required for dissolution (preparation time) was 36 minutes.
In a four-necked flask equipped with a dropping device, a thermometer, and a reflux tube, 9.59 parts of ethyl lactate (prepared solvent) was charged and bubbled with nitrogen gas for 30 minutes. This charged solvent was heated to about 73 ° C. under a nitrogen seal. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 73 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 73 ° C.
The reaction mixture was cooled to about room temperature and diluted with 61.52 parts of tetrahydrofuran. The diluted reaction mixture was poured into 536 parts of a mixed solvent of water and methanol (water: methanol (weight ratio) = 2: 8) with stirring, and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 249 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 26.3 parts of resin A4.
Yield: 68.4%
Mw: 7.7 × 10 ³ , Mw / Mn: 1.73
Structural unit composition ratio in resin A4: A / B / C / D = 57/10/11/22

Comparative Example 1 (Production of Resin B1 by Conventional Production Method (Drip Polymerization))
Monomer A 25.00 parts, Monomer B 2.95 parts, Monomer C 2.73 parts, Monomer D 7.69 parts, Azobisisobutyronitrile 0.24 parts, Azobis-2,4-dimethylvaleronitrile 1. 08 parts and 28.74 parts of ethyl lactate were mixed to prepare a solution (drop solution). The mixture was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time required for dissolution (preparation time) was 61 minutes.
In a four-necked flask equipped with a dropping device, a thermometer, and a reflux tube, 9.59 parts of ethyl lactate (prepared solvent) was charged under a nitrogen atmosphere, and the temperature was raised to about 73 ° C. under a nitrogen atmosphere. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 73 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 73 ° C.
The reaction mixture was cooled to about room temperature and diluted with 61.39 parts of tetrahydrofuran. The diluted reaction mixture was poured into 536 parts of a mixed solvent of water and methanol (water: methanol (weight ratio) = 2: 8) with stirring, and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 249 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 25.9 parts of resin B1.
Yield: 67.4%
Mw: 6.7 × 10 ³ , Mw / Mn: 1.74
Structural unit composition ratio in resin B1: A / B / C / D = 56/9/10/25

  Table 1 summarizes the comparison results between Examples 1 to 4 and Comparative Example 1.

ＧＢＬ：γ−ブチロラクトン（１２．８）
ＣＨＮ：シクロヘキサノール（１１．４）
ＡＴＮ：アセトニトリル（１２．１１）
ＥＬ：乳酸エチル（１１．６）
（括弧内の数値は、溶解度パラメーターの数値[ｃａｌ／ｍｏｌ]^１／２を表す。）

GBL: γ-butyrolactone (12.8)
CHN: cyclohexanol (11.4)
ATN: acetonitrile (12.11)
EL: ethyl lactate (11.6)
(The numerical value in parentheses represents the numerical value [cal / mol] ^1/2 of the solubility parameter.)

Example 5 (Production of Resin A5 by Drop Polymerization of this Production Method)
Monomer E 12.75 g, Monomer F 5.19 g, Monomer D 7.41 g, Monomer G 12.85 g, Azobisisobutyronitrile 0.248 g, Azobis-2,4-dimethylvaleronitrile 1.13 g, γ-butyrolactone A solution (drop solution) was prepared by mixing 32.59 g and 3.80 g of tetrahydrofuran. The mixture was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time required for dissolution (preparation time) was 24 minutes.
In a four-necked flask equipped with a dropping device, a thermometer and a reflux tube, 24.26 parts of γ-butyrolactone (charged solvent) and 2.25 g of monomer E were charged in a nitrogen atmosphere, and 70 ° C. in a nitrogen atmosphere. The temperature was raised to the extent. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 70 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 70 ° C.
The reaction mixture was cooled and diluted with 44.48 g of tetrahydrofuran. The diluted reaction mixture was poured into 526 parts of methanol kept at about 40 ° C. while stirring, and stirred for 1 hour while maintaining about 40 ° C., and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 263 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 33.4 parts of resin A5.
Yield: 82.6%
Mw: 1.3 × 10 ⁴ , Mw / Mn: 1.62
Structural unit composition ratio in resin A5:
E / F / D / G = 29.7 / 13.8 / 14.5 / 41.9

Comparative Example 2 (Production of Resin B2 by Conventional Production Method (Drip Polymerization))
Monomer E 12.75 g, Monomer F 5.19 g, Monomer D 7.41 g, Monomer G 12.85 g, Azobisisobutyronitrile 0.248 g, Azobis-2,4-dimethylvaleronitrile 1.13 g, Ethyl lactate 36 .39 g was mixed to prepare a solution (drip solution). The mixture was stirred until the monomers and polymerization initiator used were completely dissolved in the solvent (visual confirmation). The time required for dissolution (preparation time) was 27 minutes.
In a four-necked flask equipped with a dropping device, a thermometer and a reflux tube, 24.26 parts of ethyl lactate (prepared solvent) and 2.25 g of monomer E were charged in a nitrogen atmosphere, and about 70 ° C. in a nitrogen atmosphere. The temperature was raised to. Subsequently, the dropping solution was dropped into the four-necked flask at a constant rate by the dropping device so that the reaction mixture in the four-necked flask kept about 70 ° C. The dropping time was 1 hour. The reaction mixture after completion of the dropwise addition was kept warm for 5 hours while maintaining the temperature at about 70 ° C.
The reaction mixture was cooled and diluted with 44.48 g of tetrahydrofuran. The diluted reaction mixture was poured into 526 parts of methanol kept at about 40 ° C. while stirring, and stirred for 1 hour while maintaining about 40 ° C., and the deposited precipitate was collected by filtration. The precipitate (resin) collected by filtration was mixed with 263 parts of methanol and stirred, and the resin was further filtered to wash the resin. This washing operation was repeated two more times. Then, it dried at 40 degreeC under pressure reduction for 12 hours, and obtained 32.3 parts of resin B2.
Yield: 79.8%
Mw: 1.2 × 10 ⁴ , Mw / Mn: 1.68
Structural unit composition ratio in resin B2:
E / F / D / G = 28.7 / 13.6 / 14.9 / 42.9

  The comparison results of Example 5 and Comparative Example 2 are summarized in Table 2.

  The present invention is useful for producing a resin for a resist composition.

Claims (6)

The manufacturing method of resin for resist compositions which has the process of superposing | polymerizing a monomer in the mixed solvent containing a solvent (1) and a solvent (2).
Solvent (1): Solubility parameter is 11.4 to 13.0 [cal / mol] ^1/2
A solvent that is within the range of
Solvent (2): Tetrahydrofuran The step
The method for producing a resin for a resist composition according to claim 1, wherein the monomer is polymerized by the action of a polymerization initiator. The step
Preparing a mixed solution comprising at least a part of the monomer, at least a part of the solvent (2), and a polymerization initiator;
The method for producing a resin for a resist composition according to claim 1, further comprising a step of dripping the mixed solution into the solvent (1).   The method for producing a resin for a resist composition according to any one of claims 1 to 3, wherein the mixed solvent substantially comprises the solvent (1) and the solvent (2).   The method for producing a resin for a resist composition according to claim 1, wherein the monomer contains a monomer having an acid labile group. The method for producing a resin for a resist composition according to claim 5, wherein the monomer having an acid labile group is a monomer represented by formula (a1-1) or formula (a1-2).

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent a group represented by —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, k1 represents an integer of 1 to 7, and * represents − Represents a bond with CO-.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n2 represents an integer of 0 to 3. ]