JP2006037117A - Polymer compound for photoresist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer compound for a photoresist containing very small content of impurities such as metal components. <P>SOLUTION: This polymer compound for the photoresist is obtained by subjecting a monomer mixture, containing at least one kind of monomer selected from a monomer (a) containing a lactone skeleton, a monomer (b) containing a group releasable with an acid and becoming alkali-soluble, and a monomer (c) containing an alicyclic skeleton with a hydroxy group, to drop polymerization. By carrying out (i) an extraction step (B) subjecting the polymer obtained by the drop polymerization to an extracting operation using an organic solvent and water, or (ii) a filtration step (I) subjecting a specific polymer solution containing the polymer obtained by the drop polymerization to passing through a specific filter, the content of sodium is reduced to 95 wt.ppb or lower (based on the weight of polymer). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photoresist polymer compound useful for the preparation of a photoresist resin composition for use in semiconductor microfabrication, etc., a photoresist polymer solution containing the photoresist polymer compound, and a photoresist resin composition And a method for producing a semiconductor using the photoresist resin composition.

  The positive photoresist used in the semiconductor manufacturing process must have properties such as the property that the irradiated part changes to alkali-soluble by light irradiation, adhesion to the silicon wafer, plasma etching resistance, transparency to the light used, etc. Don't be. The positive photoresist is generally used as a solution containing a main polymer, a photo-oxidant, and several additives for adjusting the above characteristics. On the other hand, lithography exposure light sources used for semiconductor manufacturing have become shorter in wavelength year by year, and ArF excimer lasers having a wavelength of 193 nm are promising as next-generation exposure light sources. As resist polymers used in this ArF excimer laser exposure machine, various polymers having a repeating unit containing a lactone skeleton having high adhesion to a substrate and a repeating unit containing an alicyclic hydrocarbon skeleton excellent in etching resistance have been proposed. Yes.

  These polymers are usually isolated by polymerizing the monomer mixture and then subjecting the polymerization solution to a precipitation operation. However, since the polymer obtained in this manner contains impurities such as metal components, there is a problem that desired resist performance (sensitivity, etc.) cannot be obtained when used as a resin component of a photoresist resin composition. In particular, when a metal component such as sodium or iron is included, the electrical characteristics of the semiconductor and the like deteriorate. In addition, there are problems that the surface of the polymer particles becomes hard at the time of drying or the polymer particles are fused with each other and are not easily dissolved in the resist solvent.

  Accordingly, an object of the present invention is to provide a polymer compound for a photoresist having a very small content of impurities such as metal components. In addition to the above points, another object of the present invention is to provide a photoresist polymer compound that is easily and reliably dissolved in a resist solvent. Still another object of the present invention is to provide a polymer compound for photoresist that does not adversely affect electrical characteristics of a semiconductor or the like when used as a resin component of a resin composition for photoresist. Another object of the present invention is to provide a photoresist polymer solution and a photoresist resin composition containing such a photoresist polymer compound, and a method for producing a semiconductor using the photoresist resin composition. There is to do.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have applied a photoresist polymer to an extraction operation using an organic solvent and water, or include a photoresist polymer and the metal content is a specific value. It has been found that when the following polymer solution is passed through a filter composed of a specific porous polyolefin film, metal components that adversely affect resist performance and electrical characteristics such as semiconductors can be easily removed. The present invention has been completed based on these findings.

  That is, the present invention relates to a monomer (a) containing a lactone skeleton, a monomer (b) containing a group that becomes alkali-soluble upon removal by an acid, and a monomer containing an alicyclic skeleton having a hydroxyl group A polymer compound for photoresist obtained by subjecting a monomer mixture containing at least one monomer selected from (c) to drop polymerization, wherein (i) a polymer produced by the drop polymerization is (B), or (ii) produced by the above-described dropping polymerization, by subjecting to an extraction operation using an organic solvent and water, and distributing the produced polymer to the organic solvent layer and the metal component as an impurity to the aqueous layer. Passing a polymer solution containing the prepared polymer and having a metal content of 1000 ppb or less with respect to the polymer through a filter composed of a porous polyolefin membrane having a cation exchange group Through the I), sodium content (polymer weight) provides a photoresist polymeric compound that is reduced to less than 95 weight ppb.

  In this polymer compound for photoresist, the molecular weight distribution is, for example, in the range of 1.74 to 2.50.

（式中、Ｒ¹は（メタ）アクリロイルオキシ基を含む基を示し、Ｒ²、Ｒ³、Ｒ⁴はそれぞれ低級アルキル基、ｎは０〜３の整数、ｍは０〜５の整数を示す）
で表される（メタ）アクリル酸エステルモノマーが含まれる。 The monomer (a) containing the lactone skeleton includes the following formula (1a), (1b) or (1c)

(In the formula, R ¹ represents a group containing a (meth) acryloyloxy group, R ² , R ³ and R ⁴ are each a lower alkyl group, n is an integer of 0 to 3, and m is an integer of 0 to 5. )
(Meth) acrylic acid ester monomers represented by

（式中、Ｒは水素原子又はメチル基、Ｒ⁵は水素原子又は低級アルキル基、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹はそれぞれ低級アルキル基、ｎは０〜３の整数を示す）
で表される（メタ）アクリル酸エステルモノマーが含まれる。 The monomer (b) containing a group that is eliminated by an acid and becomes alkali-soluble includes the following formula (2a) or (2b):

(Wherein R is a hydrogen atom or a methyl group, R ⁵ is a hydrogen atom or a lower alkyl group, R ⁶ , R ⁷ , R ⁸ and R ⁹ are each a lower alkyl group, and n is an integer of 0 to 3)
(Meth) acrylic acid ester monomers represented by

（式中、Ｒは水素原子又はメチル基を示し、Ｒ¹⁰はメチル基、ヒドロキシル基、オキソ基又はカルボキシル基を示す。ｋは１〜３の整数を示す。ｋ個のＲ¹⁰のうち少なくとも１つはヒドロキシル基である）
で表される（メタ）アクリル酸エステルモノマーが含まれる。 The monomer (c) containing an alicyclic skeleton having a hydroxyl group includes the following formula (3a)

(In the formula, R represents a hydrogen atom or a methyl group, R ¹⁰ represents a methyl group, a hydroxyl group, an oxo group or a carboxyl group. K represents an integer of 1 to 3. At least one of k R ^{10 s} ) One is a hydroxyl group)
(Meth) acrylic acid ester monomers represented by

  The polymerization solvent in the drop polymerization may be a glycol-based or ester-based solvent. The polymerization temperature in the drop polymerization is, for example, 40 to 150 ° C.

In the extraction step (B), a polymer produced by adding an organic solvent having a specific gravity of 0.95 or less and water to the polymerization solution obtained in the polymerization step (A) in which the monomer mixture is subjected to drop polymerization is extracted. May be distributed to the organic solvent layer and the metal component as an impurity may be distributed to the aqueous layer. In addition, in the extraction step (B), an organic solvent and water having a specific gravity of 0.95 or less and a solubility parameter (SP value) of 20 MPa ^1/2 or less in a glycol-based or ester-based solvent solution of the polymer produced by the drop polymerization. And the resulting polymer may be distributed to the organic solvent layer and the metal component as an impurity may be distributed to the aqueous layer.

  The polymer compound for photoresists of the present invention may be a polymer compound obtained through a precipitation purification step (C) in which a polymer produced by dropping polymerization is further precipitated or reprecipitated. In the precipitation purification step (C), the polymer may be precipitated or reprecipitated by adding a solution containing the polymer produced by the drop polymerization and a glycol-based or ester-based solvent to a solvent containing at least a hydrocarbon.

  The high molecular compound for photoresist of the present invention may be a high molecular compound obtained through a repulping step (D) in which a polymer produced by dropping polymerization is repulped with a solvent. A hydrocarbon solvent can be used as the repulping solvent.

  The high molecular compound for photoresist of the present invention may be a high molecular compound obtained through a rinsing step (E) in which a polymer formed by dropping polymerization is rinsed with a solvent. As the rinsing solvent, water such as a hydrocarbon solvent and / or ultrapure water can be used.

  The polymer compound for photoresist of the present invention is further subjected to a re-dissolution step (G) in which a polymer produced by dropping polymerization is subjected to precipitation purification and then redissolved in an organic solvent to prepare a polymer solution. The resulting polymer compound may be used. As the redissolving solvent, at least one solvent selected from glycol solvents, ester solvents, and ketone solvents can be used.

  The photoresist polymer compound of the present invention further comprises an evaporation step (H) in which a polymer solution obtained by re-dissolving in an organic solvent is concentrated to remove a low boiling point solvent to prepare a photoresist polymer solution. It may be a polymer compound obtained through the process.

  The photoresist polymer compound of the present invention corresponds to at least one monomer selected from the monomers (a), (b), and (c) provided before the step (I). The polymer compound obtained through the filtration process (J) which filters the polymer solution containing the polymer which has a repeating unit, and removes an insoluble matter may be sufficient.

  The photoresist polymer compound of the present invention corresponds to at least one monomer selected from the monomers (a), (b), and (c) provided before the step (I). The polymer compound obtained through the water washing process (K) which wash | cleans the polymer solution containing the polymer which has a repeating unit with water, and reduces the metal content in a polymer solution may be sufficient.

  The present invention also provides a photoresist polymer solution containing the above-described photoresist polymer compound.

  The present invention further provides a photoresist resin composition comprising at least the above-described photoresist polymer compound and a photoacid generator.

  The present invention further provides a method for producing a semiconductor comprising a step of forming a photosensitive layer using the above resin composition for photoresist, and forming a pattern through exposure and development.

  According to the present invention, there is provided a polymer compound for photoresist having a very small content of impurities such as metal components. In addition to the above points, a photoresist polymer compound that can be easily and reliably dissolved in a resist solvent is provided. Further, when used as a resin component of a photoresist resin composition, a photoresist polymer compound that does not adversely affect electrical properties of a semiconductor or the like is provided. According to the present invention, there are further provided a photoresist polymer solution and a photoresist resin composition containing such a photoresist polymer compound, and a method for producing a semiconductor using the photoresist resin composition. Is done.

[Polymerization step (A)]
In the polymerization step (A), (a) a monomer containing a lactone skeleton, (b) a monomer containing a group that is eliminated by an acid and becomes alkali-soluble, and (c) an alicyclic skeleton having a hydroxyl group. A monomer mixture containing at least one monomer selected from the containing monomers (also referred to as a “monomer mixture” for convenience when there is only one monomer) is subjected to drop polymerization and polymer Is generated.

The monomer (a) containing a lactone skeleton imparts a substrate adhesion function to the polymer. Further, depending on the structure, an acid-eliminating function (alkali-soluble function) may be imparted to the polymer (such as a repeating unit having a β- (meth) acryloyloxy-γ-butyrolactone skeleton). The lactone skeleton is not particularly limited, and examples thereof include a lactone skeleton having about 4 to 20 members. The lactone skeleton may be a monocycle having only a lactone ring, or may be a polycyclic ring obtained by condensing a non-aromatic or aromatic carbocyclic ring or heterocyclic ring to a lactone ring. As a typical lactone skeleton, 3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one ring (= 2-oxatricyclo [4.2.1.0 ^4,8 ] nonane -3-one ring), 3-oxatricyclo [4.3.1.1 ^4,8 ] undecan-2-one ring, γ-butyrolactone ring, δ-valerolactone ring, ε-caprolactone ring and the like. . In many cases, the lactone skeleton is bonded to a carbon atom constituting the main chain of the polymer via an ester bond, or an ester bond and a linking group such as an alkylene group.

A typical example of the monomer (a) containing a lactone skeleton is a (meth) acrylic acid ester monomer represented by the formula (1a), (1b) or (1c). In the formula, R ¹ , R ² , R ³ and R ⁴ are groups bonded to a ring, R ¹ represents a group containing a (meth) acryloyloxy group, and R ² , R ³ and R ⁴ are each lower. An alkyl group, n represents an integer of 0 to 3, and m represents an integer of 0 to 5. Examples of the group containing the (meth) acryloyloxy group include (meth) acryloyloxy groups; (meth) acryloyloxyalkyl groups such as (meth) acryloyloxymethyl groups and (meth) acryloyloxyethyl groups. R ¹ is the 5-position of the 3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one ring in formula (1a) and 3-oxatricyclo [ ⁴ in formula (1b). .3.1.1 ^4,8 ] In the 6-position of the undecan-2-one ring, in formula (1c), it is often bonded to the α-position or β-position of the γ-butyrolactone ring.

Examples of the lower alkyl group for R ² , R ³ and R ⁴ include C _1-4 alkyl groups such as methyl, ethyl, isopropyl, propyl, butyl, isobutyl, s-butyl and t-butyl groups. Preferred lower alkyl groups include a methyl group or an ethyl group, with a methyl group being particularly preferred.

In the (meth) acrylic acid ester monomer represented by the formula (1a), n R ^{2 s} may be the same group or different from each other. R ² is often bonded to a carbon atom at the bridgehead position.

As a typical example of the (meth) acrylic acid ester monomer represented by the formula (1a), 5-acryloyloxy-3-oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one ( = 9-acryloyloxy-2-oxatricyclo [4.2.1.0 ^4,8 ] nonan-3-one = 5-acryloyloxy-2,6-norbornanecarbolactone), 5-methacryloyloxy-3- Oxatricyclo [4.2.1.0 ^4,8 ] nonan-2-one (= 9-methacryloyloxy-2-oxatricyclo [4.2.1.0 ^4,8 ] nonan-3-one = 5-methacryloyloxy-2,6-norbornanecarbolactone).

In the (meth) acrylic acid ester monomer represented by the formula (1b), the n R ^{3 s} may be the same group or different from each other. R ³ is often bonded to a bridgehead carbon atom.

As a representative example of the (meth) acrylic acid ester monomer represented by the formula (1b), 6-acryloyloxy-3-oxatricyclo [4.3.1.1 ^4,8 ] undecan-2-one, 6-methacryloyloxy-3-oxatricyclo [4.3.1.1 ^4,8 ] undecan-2-one and the like.

In the (meth) acrylic acid ester monomer represented by the formula (1c), the m R ^{4 s} may be the same group or different from each other. m is preferably about 0 to 3.

  Representative examples of the (meth) acrylic acid ester monomer represented by the formula (1c) include, for example, α-acryloyloxy-γ-butyrolactone, α-acryloyloxy-α-methyl-γ-butyrolactone, α-acryloyloxy. -Β, β-dimethyl-γ-butyrolactone, α-acryloyloxy-α, β, β-trimethyl-γ-butyrolactone, α-acryloyloxy-γ, γ-dimethyl-γ-butyrolactone, α-acryloyloxy-α, γ, γ-trimethyl-γ-butyrolactone, α-acryloyloxy-β, β, γ, γ-tetramethyl-γ-butyrolactone, α-acryloyloxy-α, β, β, γ, γ-pentamethyl-γ-butyrolactone Α-methacryloyloxy-γ-butyrolactone, α-methacryloyloxy-α-methyl-γ-butyrolactone, α-methacryloyloxy-β, β-dimethyl-γ-butyrolactone, α-methacryloyloxy-α, β, β-trimethyl-γ-butyrolactone, α-methacryloyloxy-γ, γ-dimethyl-γ-butyrolactone, α-methacryloyl Oxy-α, γ, γ-trimethyl-γ-butyrolactone, α-methacryloyloxy-β, β, γ, γ-tetramethyl-γ-butyrolactone, α-methacryloyloxy-α, β, β, γ, γ-pentamethyl Α- (meth) acryloyloxy-γ-butyrolactones such as γ-butyrolactone; β- (meth) acryloyloxy-γ-butyrolactones such as β-acryloyloxy-γ-butyrolactone and β-methacryloyloxy-γ-butyrolactone Etc.

  The compounds represented by the formulas (1a), (1b) and (1c) can be obtained by subjecting the corresponding alcohol compound and (meth) acrylic acid or a reactive derivative thereof to a conventional esterification reaction. .

The monomer (b) containing a group which is eliminated by an acid and becomes alkali-soluble imparts an alkali-soluble function to the polymer. As a typical example of the monomer (b) containing a group that is eliminated by an acid and becomes alkali-soluble, a (meth) acrylic acid ester monomer represented by the formula (2a) or (2b) can be given. In the formula, R represents a hydrogen atom or a methyl group, R ⁵ represents a hydrogen atom or a lower alkyl group, R ⁶ , R ⁷ , R ⁸ and R ⁹ each represent a lower alkyl group, and n represents an integer of 0 to 3. R ⁷ and R ⁹ are groups bonded to the ring. Examples of the lower alkyl group include the same groups as described above.

In the (meth) acrylic acid ester monomer represented by the formula (2a), n R ^{7 s} may be the same group or different from each other. R ⁷ is often bonded to a carbon atom at the bridgehead position.

  Representative examples of the (meth) acrylic acid ester monomer represented by the formula (2a) include, for example, 1- (1-acryloyloxy-1-methylethyl) adamantane, 1- (1-acryloyloxy-1-methyl) Ethyl) -3,5-dimethyladamantane, 1- (1-methacryloyloxy-1-methylethyl) adamantane, 1- (1-methacryloyloxy-1-methylethyl) -3,5-dimethyladamantane, and the like.

In the (meth) acrylic acid ester monomer represented by the formula (2b), the n R ^{9 s} may be the same group or different from each other. R ⁹ is often bonded to a carbon atom at the bridgehead position.

  Representative examples of the (meth) acrylic acid ester monomer represented by the formula (2b) include, for example, 2-acryloyloxy-2-methyladamantane, 2-acryloyloxy-2,5,7-trimethyladamantane, 2- And methacryloyloxy-2-methyladamantane and 2-methacryloyloxy-2,5,7-trimethyladamantane.

The monomer (c) containing an alicyclic skeleton having a hydroxyl group imparts etching resistance and substrate adhesion functions to the polymer. The alicyclic hydrocarbon group may be a monocyclic hydrocarbon group or a polycyclic (bridged cyclic) hydrocarbon group. A typical example of the monomer (c) containing an alicyclic skeleton having a hydroxyl group is a (meth) acrylic acid ester monomer represented by the formula (3a). In the formula, R represents a hydrogen atom or a methyl group, and R ¹⁰ represents a substituent bonded to the ring and represents a methyl group, a hydroxyl group, an oxo group or a carboxyl group. k represents an integer of 1 to 3. The k R ^{10 s} may be the same group or different from each other. At least one of the k R ¹⁰ is a hydroxyl group. R ¹⁰ is often bonded to a carbon atom at the bridgehead position.

  Representative examples of the (meth) acrylic acid ester monomer represented by the formula (3a) include, for example, 1-acryloyloxy-3-hydroxy-5,7-dimethyladamantane, 1-hydroxy-3-methacryloyloxy-5. , 7-dimethyladamantane, 1-acryloyloxy-3-hydroxyadamantane, 1-hydroxy-3-methacryloyloxyadamantane, 1-acryloyloxy-3,5-dihydroxyadamantane, 1,3-dihydroxy-5-methacryloyloxyadamantane, etc. Is mentioned.

  The monomer to be used for polymerization may be any one of the above monomers (a), (b), and (c), but two or more of the three types of monomers, particularly It is preferable to use three types of monomers. Moreover, you may copolymerize another monomer as needed. The polymerization can be performed by a conventional method such as solution polymerization or melt polymerization.

  The polymerization solvent may be any solvent that is usually used when polymerizing acrylic monomers and olefin monomers. For example, glycol solvents, ester solvents, ketone solvents, ether solvents, these solvents Examples thereof include mixed solvents. Examples of glycol solvents include propylene glycol solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene Ethylene glycol solvents such as glycol monobutyl ether and ethylene glycol monobutyl ether acetate are included. Examples of ester solvents include lactic acid ester solvents such as ethyl lactate; propionate solvents such as methyl 3-methoxypropionate; acetate solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. . Ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, and the like. The ether solvent includes diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane and the like.

  Preferred polymerization solvents include glycol solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, ester solvents such as ethyl lactate, ketone solvents such as methyl isobutyl ketone and methyl amyl ketone, and mixed solvents thereof. . In particular, a solvent containing at least propylene glycol monomethyl ether acetate, such as a single solvent for propylene glycol monomethyl ether acetate, a mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, a mixed solvent of propylene glycol monomethyl ether acetate and ethyl lactate, etc. preferable.

  A dropping polymerization method is used as the polymerization method. The dropping polymerization method refers to a method in which polymerization is carried out while successively dropping or adding a monomer (solution) and / or a polymerization initiator (solution) into the system. By the dropping polymerization method, a polymer having a uniform copolymer composition obtained in the early stage and later stage of polymerization can be obtained. A well-known thing can be used as a polymerization initiator. The polymerization temperature is, for example, about 40 to 150 ° C, preferably about 60 to 120 ° C.

  The obtained polymerization solution (polymer dope) may be subjected to a filtration step for removing insoluble matters. The pore diameter of the filter medium used for filtration is, for example, 1 μm or less, preferably 0.8 μm or less.

[Extraction step (B)]
In the extraction step (B), the polymer produced by polymerization is subjected to an extraction operation (washing operation) using an organic solvent and water, the produced polymer is applied to the organic solvent layer, and the metal component as an impurity is applied to the aqueous layer. Distribute. By this step, metal components that adversely affect the resist performance can be efficiently removed from the polymer. The material to be treated for the extraction step (B) may be a polymer produced by polymerization or a solution containing the polymer, a polymerization solution at the end of polymerization (polymer dope), diluted to this polymerization solution, concentrated, filtered, Any of the solutions after appropriate processing such as washing may be used. The organic solvent may be any solvent that can dissolve the polymer and can be separated from water. Moreover, the usage-amount of an organic solvent and water can be suitably set in the range which can be liquid-separated into an organic solvent layer and an aqueous layer.

In a preferred embodiment, an organic solvent having a specific gravity of 0.95 or less (particularly, an organic solvent having a solubility parameter (SP value) of 20 MPa ^1/2 or less) and water are added to the polymerization solution obtained in the polymerization step (A). Extract (wash with water). In addition, an organic solvent having a specific gravity of 0.95 or less and a solubility parameter (SP value) of 20 MPa ^1/2 or less and water are added to a glycol-based or ester-based solvent solution of a polymer produced by polymerization and extracted (washed with water). ) Is also preferable. A value of 20 to 25 ° C. can be adopted as the specific gravity of the organic solvent. The SP value of the organic solvent is, for example, the method described in “Polymer Handbook”, 4th edition, pages VII-675 to VII-711 [in particular, the formulas (B3) and (B8) on page 676 ]. Further, as the SP value of the organic solvent, the values shown in Table 1 (page VII-683) and Tables 7 to 8 (pages VII-688 to VII-711) of the document can be adopted.

  The glycol-based or ester-based solvent solution of the polymer produced by the polymerization may be a polymerization solution (polymer dope) at the end of the polymerization, and this polymerization solution is subjected to appropriate treatment such as dilution, concentration, filtration, and washing. It may be a solution after application. Examples of the glycol solvent and ester solvent include the solvents exemplified above.

Glycol solvents such as propylene glycol monomethyl ether acetate and ester solvents such as ethyl lactate have a specific gravity close to that of water (close to 1), and are difficult to separate from water. When an organic solvent having a specific gravity of 0.95 or less and an SP value of 20 MPa ^1/2 or less (for example, 13 to 20 MPa ^1/2 ) is added to a polymer solution containing a system solvent, the separation between the organic layer and the aqueous layer becomes It becomes extremely easy. If the specific gravity of the organic solvent to be added exceeds 0.95, there is not much difference in specific gravity with water, and it is difficult to obtain good liquid separation. Moreover, since the solubility with respect to water will increase when the SP value of the organic solvent to add exceeds 20 MPa1 ^{/ 2} , it is difficult to obtain a good liquid separation property. The specific gravity of the organic solvent to be added is preferably 0.6 to 0.95, more preferably 0.7 to 0.85 (particularly 0.7 to 0.82). The SP value of the organic solvent to be added is preferably 16 to 19 MPa ^1/2 , more preferably 16.5 to 18.5 MPa ^1/2 (particularly 16.5 to 18 MPa ^1/2 ).

Representative examples of organic solvents having a specific gravity of 0.95 or less and an SP value of 20 MPa ^1/2 or less include, for example, hexane (specific gravity 0.659; SP value 14.9), octane (specific gravity 0.703; SP 15.6), aliphatic hydrocarbons such as dodecane (specific gravity 0.749; SP value 16.2); alicyclic hydrocarbons such as cyclohexane (specific gravity 0.779; SP value 16.8); ethylbenzene (specific gravity) 0.862; SP value 18.0), p-xylene (specific gravity 0.857; SP value 18.0), toluene (specific gravity 0.867; SP value 18.2), benzene (specific gravity 0.874; SP value) Aromatic hydrocarbons such as 18.8); ethers such as diisopropyl ether (specific gravity 0.726; SP value 14.1); diisobutyl ketone (specific gravity 0.806; SP value 16.0), methyl isobutyl ketone ( Specific gravity 0.796; SP value 17.2), methyl propyl ketone (specific gravity 0.809; SP value 17.8), methyl isopropyl ketone (specific gravity 0.803; SP value 17.4), methyl ethyl ketone (specific gravity 0.805) SP value 19.0), ketones such as methyl amyl ketone (specific gravity 0.815; SP value 17.6); isopropyl acetate (specific gravity 0.872; SP value 17.2), butyl acetate (specific gravity 0.881; Examples include esters such as SP value 17.4) and propyl acetate (specific gravity 0.889; SP value 18.0). The specific gravity in the parentheses is a value of 20 ° C. (however, the value of 25 ° C. for benzene, p-xylene, ethylbenzene and methyl isobutyl ketone), and the unit of SP value is MPa ^1/2 .

  Among these solvents, ketones such as diisobutyl ketone, methyl isobutyl ketone, methyl propyl ketone, methyl isopropyl ketone, and methyl amyl ketone are preferable.

The amount of the organic solvent having a specific gravity of 0.95 or less and an SP value of 20 MPa ^1/2 or less can be appropriately selected in consideration of extraction efficiency, operability and the like. Usually, a polymer glycol-based or ester-based solvent solution The amount is 10 to 300 parts by weight, preferably about 20 to 200 parts by weight with respect to 100 parts by weight. Further, the amount of water to be added can also be appropriately selected in consideration of extraction efficiency, operability, etc., but is usually based on 100 parts by weight of the total amount of the glycol-based or ester-based solvent solution of the polymer and the organic solvent. The amount is about 5 to 300 parts by weight, preferably about 10 to 200 parts by weight.

  The extraction (washing) operation can be performed by a conventional method, and may be performed by any of batch, semi-batch, and continuous methods. The extraction operation may be repeated a plurality of times (for example, about 2 to 10 times). The extraction temperature can be appropriately selected in consideration of operability and solubility, and is, for example, 0 to 100 ° C., preferably about 25 to 50 ° C.

  The obtained organic solvent layer may be subjected to a filtration step for removing insoluble matters. The pore diameter of the filter medium used for filtration is, for example, 1 μm or less, preferably 0.5 μm or less, and more preferably 0.3 μm or less.

[Precipitation purification step (C)]
In the precipitation purification step (C), the polymer produced by the polymerization is precipitated or reprecipitated. By this precipitation purification process, raw material monomers and oligomers can be efficiently removed. The liquid to be treated for the precipitation purification treatment may be a solution containing a polymer produced by polymerization, such as a polymerization solution at the end of polymerization (polymer dope), dilution, concentration, filtration, washing, extraction, etc. in this polymerization solution. Any of the solutions after the appropriate treatment may be used. A preferable liquid to be treated includes the organic solvent layer obtained in the extraction step (B) or a solution obtained by subjecting the organic solvent layer to a filtration treatment.

  The solvent used for precipitation or reprecipitation (precipitation solvent) may be a poor polymer solvent, such as aliphatic hydrocarbons (pentane, hexane, heptane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane). Hydrocarbons such as aromatic hydrocarbons (benzene, toluene, xylene, etc.); halogenated aliphatic hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.), halogenated aromatic hydrocarbons (chlorobenzene, dichlorobenzene, etc.) Halogenated hydrocarbons such as nitromethane, nitroethane, etc .; acetonitrile, benzonitrile, etc., nitriles; chain ethers (diethyl ether, diisopropyl ether, dimethoxyethane, etc.), cyclic ethers (tetrahydrofuran, dioxane, etc.), etc. Tel; Acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and other ketones; Ethyl acetate, butyl acetate and other esters; Dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate and other carbonates; Methanol, ethanol, propanol, isopropyl alcohol, butanol It can be suitably selected from alcohols such as acetic acid; carboxylic acids such as acetic acid; water; mixed solvents containing these solvents.

  Among these solvents, a mixed solvent containing at least hydrocarbons (particularly aliphatic hydrocarbons such as hexane and heptane) is preferable as the precipitation solvent. In such a mixed solvent containing at least hydrocarbon, the mixing ratio of hydrocarbon to other solvent (for example, ester such as ethyl acetate) is, for example, hydrocarbon / other solvent = 10/90 to 99 / 1 (volume ratio at 25 ° C., the same applies hereinafter), preferably 30/70 to 98/2, more preferably about 50/50 to 97/3.

  In a preferred embodiment of this step, a solution containing a polymer produced by polymerization and a glycol-based or ester-based solvent is added to a solvent containing at least a hydrocarbon to precipitate or reprecipitate the polymer. As a solution containing a polymer produced by polymerization and a glycol-based or ester-based solvent, an organic solvent layer containing the glycol-based or ester-based solvent obtained in the extraction step (B), or a solution obtained by subjecting this to a filtration treatment, etc. Can be mentioned.

[Repulping process (D)]
In the repulping step (D), the polymer produced by polymerization is repulped with a solvent. By providing this step, residual monomers and low molecular weight oligomers adhering to the polymer can be efficiently removed. In addition, because the high-boiling solvent having affinity for the polymer is removed, the surface of the polymer particles can be hardened in the subsequent drying step or the like, and fusion between the polymer particles can be prevented. Therefore, the solubility of the polymer in the resist solvent is remarkably improved, and the resin composition for photoresist can be easily and efficiently prepared.

  Examples of the object to be treated for the repulping treatment include the above-described precipitation-purified polymer (for example, a polymer after the solvent is removed by decantation, filtration, etc. after precipitation purification).

  As the solvent (repulping solvent) used for the repulping treatment, a poor solvent for the polymer used for precipitation or reprecipitation is preferable. Of these, hydrocarbon solvents are particularly preferred. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene. You may use these in mixture of 2 or more types. Among these, aliphatic hydrocarbons, particularly hexane or heptane, or a mixed solvent containing hexane or heptane is preferable.

  The amount of the repulping solvent used is, for example, about 1 to 200 times, preferably about 5 to 100 times, more preferably about 10 to 50 times the weight of the polymer. Although the temperature at the time of performing a repulping process changes with kinds etc. of the solvent to be used, generally it is 0-100 degreeC, Preferably it is about 10-60 degreeC. The repulping process is performed in a suitable container. The repulping process may be performed a plurality of times. The treated liquid (repulp liquid) is removed by decantation or the like.

[Rinse process (E)]
In the rinsing step (E), the polymer formed by polymerization is rinsed with a solvent. By this step, similar to the repulping step, residual monomers and low molecular weight oligomers adhering to the polymer can be efficiently removed. In addition, because the high-boiling solvent having affinity for the polymer is removed, the surface of the polymer particles can be hardened in the subsequent drying step or the like, and fusion between the polymer particles can be prevented. Therefore, the solubility of the polymer in the resist solvent is remarkably improved, and the preparation of the photoresist resin composition becomes easy. Moreover, the metal component adhering to the polymer surface can be efficiently removed by using water as the rinse solvent. Therefore, the deterioration of resist performance due to the metal component can be remarkably prevented.

  As an object to be subjected to a rinsing treatment, the precipitate-purified polymer (for example, a polymer after the solvent is removed by decantation after purification) or the polymer subjected to the repulping treatment (for example, after the repulping treatment, And the like after removal of the solvent by decantation or the like.

  As the solvent (rinsing solvent) used for the rinsing treatment, a poor solvent for the polymer used for precipitation or reprecipitation is preferable. Of these, hydrocarbon solvents are particularly preferred. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene. You may use these in mixture of 2 or more types. Among these, aliphatic hydrocarbons, particularly hexane or heptane, or a mixed solvent containing hexane or heptane is preferable. In order to remove the metal component from the polymer, water as a rinsing solvent, particularly water having a sodium content of 5 wt ppb or less (preferably 3 wt ppb or less, more preferably 1.5 wt ppb or less), such as ultrapure water, is used. Is preferred.

  The usage-amount of a rinse solvent is 1-100 weight times with respect to a polymer, for example, Preferably it is about 2-20 weight times. The temperature at which the rinsing treatment is performed varies depending on the type of solvent used and the like, but is generally 0 to 100 ° C., preferably about 10 to 60 ° C. The rinsing process is performed in a suitable container. The rinsing process may be performed a plurality of times. In particular, it is preferable to perform a combination of a rinsing process using a hydrocarbon solvent and a rinsing process using water. The treated liquid (rinse liquid) is removed by decantation, filtration, or the like.

[Drying step (F)]
The photoresist polymer compound of the present invention may be obtained through a drying step (F). In the drying step (F), the polymer produced by polymerization is subjected to precipitation purification, and after repulping and / or rinsing as necessary, the polymer is dried. The drying temperature of a polymer is 20-120 degreeC, for example, Preferably it is about 40-100 degreeC. Drying is preferably performed under reduced pressure, for example, 200 mmHg (26.6 kPa) or less, particularly 100 mmHg (13.3 kPa) or less.

[Remelting step (G)]
In the re-dissolution step (G), the polymer produced by the polymerization is subjected to precipitation purification, and after repulping, rinsing, and drying as necessary, the polymer is re-used in an organic solvent (resist solvent). Dissolve to prepare polymer solution. This polymer solution can be used as a polymer solution for photoresist (polymer concentration of about 10 to 40% by weight). Examples of the organic solvent include glycol solvents, ester solvents, ketone solvents, and mixed solvents exemplified as the polymerization solvent. Among these, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, methyl isobutyl ketone, methyl amyl ketone, and a mixed solution thereof are preferable, and in particular, propylene glycol monomethyl ether acetate alone solvent, propylene glycol monomethyl ether acetate and A solvent containing at least propylene glycol monomethyl ether acetate such as a mixed solvent of propylene glycol monomethyl ether and a mixed solvent of propylene glycol monomethyl ether acetate and ethyl lactate is preferably used.

[Evaporation step (H)]
In the evaporation step (H), by concentrating the polymer solution obtained in the re-dissolution step (G), a low-boiling point solvent (polymerization solvent, extraction solvent, precipitation solvent, repulp solvent, The solvent used as the rinsing solvent is distilled off to prepare a polymer solution for photoresist. In this evaporation step (H), a low-boiling point solvent is contained in the polymer solution obtained in the re-dissolution step (G), such as when the re-dissolution step (G) is provided without providing the drying step (F). Useful when In the case of providing this evaporation step (H), in the re-dissolution step (G), an organic solvent (resist solvent) in an amount more than that necessary for the preparation of the photoresist polymer solution is added, and a desired polymer concentration (for example, Concentrate to about 10-40% by weight). Concentration can be performed under normal pressure or reduced pressure.

  The photoresist polymer solution is further added with a photoacid generator and, if necessary, various additives, and is used for manufacturing semiconductors.

[Filter flow process (I)]
In the filter liquid passing step (I), a polymer having a repeating unit corresponding to at least one monomer selected from the monomers (a), (b) and (c) (hereinafter referred to as “polymer P”). And a metal solution having a metal content of 1000 weight ppb or less with respect to the polymer P is passed through a filter composed of a porous polyolefin membrane having a cation exchange group.

    The polymer P is a repeating unit corresponding to the monomer (a) [for example, a repeating unit corresponding to the (meth) acrylate monomer represented by the formula (1a), (1b) or (1c) (acrylic moiety). A repeating unit corresponding to the (meth) acrylate monomer represented by the formula (2a) or (2b). A unit (a repeating unit formed by polymerization of an acrylic moiety) and the like, and a repeating unit corresponding to the monomer (c) [for example, a (meth) acrylic acid ester monomer represented by the formula (3a) Any one of repeating units (repeating units formed by polymerization of acrylic sites), etc.] may be included, but two or more of the three repeating units, particularly three types of repeating units. Preferred is that has a unit. Moreover, this polymer P may have another repeating unit as needed.

  Said polymer P is compoundable by the method of the said process (A). More specifically, at least one selected from a monomer containing a lactone skeleton, a monomer containing a group that becomes alkali-soluble upon removal by an acid, and a monomer containing an alicyclic skeleton having a hydroxyl group It can synthesize | combine by superposing | polymerizing a monomer (an acrylic monomer, an olefin monomer, etc.) of a seed | species, and another monomer as needed. The polymerization can be performed by a conventional method such as solution polymerization or melt polymerization. As the monomer, it is preferable to use a monomer having a low metal content, for example, a metal content of 100 weight ppb or less.

  The solvent in the solution containing the polymer P is not particularly limited, and examples thereof include esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether monoacetate, ethyl lactate, and ethyl benzoate; acetone, ethyl methyl ketone, diethyl ketone, Ketones such as isobutyl methyl ketone and t-butyl methyl ketone; linear or cyclic ethers such as diethyl ether, diisopropyl ether, t-butyl methyl ether, dibutyl ether, dimethoxyethane, propylene glycol monomethyl ether, anisole, dioxane, tetrahydrofuran; methanol , Ethanol, isopropyl alcohol, butanol and other alcohols; acetonitrile, propionitrile, benzonitrile and other nitriles; benzene, toluene Aromatic hydrocarbons such as hexane, heptane and octane; alicyclic hydrocarbons such as cyclohexane; halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chlorobenzene; N, Amides such as N-dimethylformamide; carbon disulfide; water; and mixed solvents thereof. Among these, esters, ketones, mixed solvents containing these, and the like are preferable. The solvent may be a polymerization solvent or a solvent that replaces the polymerization solvent.

  The cation exchange groups possessed by the porous polyolefin membrane include strongly acidic cation exchange groups such as sulfonic acid groups and weak acid cation exchange groups such as carboxyl groups. Examples of the polyolefin constituting the polyolefin film include polyethylene such as high-density polyethylene, and polypropylene.

  As a filter composed of a porous polyolefin membrane having a cation exchange group, a hydrophilic filter is preferable. For example, “Ion Clean” manufactured by Nippon Pole Co., Ltd. is preferably used.

  In the step (I), when the solution containing the polymer P (photoresist polymer compound) is passed through a filter composed of a porous polyolefin film having a cation exchange group to remove metal ions, Hydrogen ions (acid) are generated. This hydrogen ion is preferably as small as possible because it removes the acid-eliminable group of the polymer P and lowers the resist performance. Therefore, the metal content in the polymer P-containing solution used for the filter composed of the porous polyolefin membrane is 1000 wt ppb or less (for example, 10 to 1000 wt ppb) with respect to the polymer P, and preferably 800 wt ppb or less. (For example, 10 to 800 weight ppb), more preferably 500 weight ppb or less (for example, 10 to 500 weight ppb). When the metal content exceeds 1000 weight ppb, the hydrogen ion concentration in the solution after passing through the filter becomes high and the resist performance is lowered.

  The flow rate when the solution containing the polymer P is passed through the filter varies depending on the type of the material of the polyolefin membrane, the type of the solution (solvent), etc., and the range in which the metal removal efficiency is not impaired (for example, 100 ml / min to about 100 L / min). The temperature at which the liquid is passed through the filter is usually about 0 to 80 ° C., preferably about 10 to 50 ° C. If the temperature is too high, the filter may be deteriorated or the solvent may be decomposed. If the temperature is too low, the solution viscosity becomes high and liquid passage tends to be difficult.

  By passing a solution containing the polymer P through the filter, metal ions such as sodium ions and iron ions contained in the solution are efficiently removed, and the metal content (polymer basis) is, for example, 200 weight ppb or less. Preferably, a polymer solution having a weight of 100 ppb or less can be obtained. Therefore, when the polymer P is used as the resin component of the photoresist resin composition, it does not adversely affect the electrical characteristics of the semiconductor and the like.

[Filtering step (J)]
In this invention, you may provide the filtration process (J) which filters the solution containing the polymer P and removes an insoluble matter before the said process (I). By providing the filtration step (J), it is possible to prevent clogging in the step (I) and to prevent various troubles caused by contamination of foreign substances when forming a pattern using the photoresist resin composition.

  Although it does not specifically limit as a filtering material used in a filtration process (J), Generally a membrane filter etc. are used. The pore diameter of the filter medium is usually about 0.01 to 10 μm, preferably about 0.02 to 1 μm, and more preferably about 0.05 to 0.5 μm.

[Washing process (K)]
In the present invention, before the step (I), a washing treatment step (K) for washing the solution containing the polymer P with water to reduce the metal content in the solution may be provided. If the water washing treatment step (K) is provided before the step (I), the water-soluble metal compound is efficiently removed, so that not only the load of the step (I) can be reduced but also the metal ion removal in the step (I). Accordingly, the amount of hydrogen ions generated can be reduced, and a great advantage can be obtained that the resist performance is not impaired. In particular, when the metal content of the solution containing the polymer P exceeds 1000 wt ppb, the water content can be reduced to 1000 wt ppb or less by the water washing treatment step (K) and used for the step (I). .

  The water used in the water washing treatment step (K) is preferably water having a low metal content, for example, ultrapure water having a metal content of 1 weight ppb or less. The amount of water is, for example, about 10 to 1000 parts by weight, preferably about 30 to 300 parts by weight with respect to 100 parts by weight of the liquid to be treated. The temperature at the time of performing the water washing treatment is, for example, about 10 to 50 ° C. In addition, it is possible to reduce the metal content in the polymer solution to a desired value only by the water washing treatment step (K) without providing the step (I), but in this case, the waste water containing the metal Since a large amount of is generated, the processing is costly and disadvantageous.

  When providing the said filtration process (J) and the water washing process process (K), although the order of both processes is not ask | required, the filtration process (J) is often set | placed before.

  In this invention, you may provide the process of attaching | subjecting the solution containing the polymer P to another adsorption process as needed other than the said process. Examples of other adsorption treatments include activated carbon treatment, chelate resin treatment, chelate fiber treatment, and zeta potential membrane treatment. Moreover, the said process (B), (C), (D), (E), (F), (G) or (H) can also be provided before or after the said process (I).

  The solution containing polymer P (photoresist polymer compound) that has undergone the above-described steps is used as it is, or the polymer is isolated by precipitation or reprecipitation, and used for the preparation of a resin composition for photoresist.

  The solvent used for precipitation or reprecipitation (precipitation solvent) may be a poor polymer solvent, such as aliphatic hydrocarbons (pentane, hexane, heptane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane). Etc.), hydrocarbons such as aromatic hydrocarbons (benzene, toluene, xylene, etc.); halogenated aliphatic hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.), halogenated aromatic hydrocarbons (chlorobenzene, dichlorobenzene, etc.) Halogenated hydrocarbons such as nitromethane, nitroethane, etc .; acetonitrile, benzonitrile, etc., nitriles; chain ethers (diethyl ether, diisopropyl ether, dimethoxyethane, etc.), cyclic ethers (tetrahydrofuran, dioxane, etc.), etc. Tel; Acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and other ketones; Ethyl acetate, butyl acetate and other esters; Dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate and other carbonates; Methanol, ethanol, propanol, isopropyl alcohol, butanol It can be suitably selected from alcohols such as acetic acid; carboxylic acids such as acetic acid; water; mixed solvents containing these solvents. Among these solvents, a mixed solvent containing at least hydrocarbons (particularly aliphatic hydrocarbons such as hexane and heptane) is preferable as the precipitation solvent. In such a mixed solvent containing at least hydrocarbon, the mixing ratio of hydrocarbon to other solvent (for example, ester such as ethyl acetate) is, for example, hydrocarbon / other solvent = 10/90 to 99 / 1 (volume ratio at 25 ° C., the same applies hereinafter), preferably 30/70 to 98/2, more preferably about 50/50 to 97/3. As the precipitation solvent, it is preferable to use one having a low metal content, for example, one having a metal content of 50 weight ppb or less.

  According to the method for producing a photoresist polymer compound of the present invention, a photoresist polymer compound having an extremely small content of impurities such as metal components can be efficiently produced. In particular, when the steps (A) and (B) are provided, it is possible to efficiently produce a photoresist polymer compound that is easily and reliably dissolved in a resist solvent.

  In particular, when the step (I) is included, a metal component that adversely affects the electrical characteristics of a semiconductor or the like can be efficiently removed. Therefore, when used as a resin component of a resin composition for a photoresist, a desired resist Performance can be obtained.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the numbers on the lower right of the parentheses in the structural formulas of Examples 11, 13, 14 and 15 indicate mol% of the monomer units (repeating units). In Examples 11 to 15 and Comparative Examples 4 to 6, a monomer having a metal content of 100 wt ppb or less was used. For propylene glycol monomethyl ether acetate (PGMEA) and methyl isobutyl ketone (MIBK), in Example 11, a commercially available product was distilled with a glass distillation apparatus and used with a metal content of 50 wt ppb or less. Except for Example 11, a commercially available product was used as it was. In Examples 11 to 15 and Comparative Examples 4 to 6, as a solvent (ethyl acetate, hexane) in precipitation operation and repulping operation, the metal content was reduced to 50 wt ppb or less by distillation with a glass distillation apparatus before use. As the water, ultrapure water (deionized water was subjected to membrane exchange treatment after ion exchange treatment to a metal content of 1 weight ppb or less) was used. The metal content was determined by an inductively coupled plasma mass spectrometer (ICP-MS) and indicated by a value (ppb) with respect to the finally obtained polymer amount. “Ppb” means “weight ppb”.

攪拌機、温度計、還流冷却管、滴下ロート及び窒素導入管を備えたセパラブルフラスコに、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を３３ｇ導入し、７５℃に昇温後、１−ヒドロキシ−３−メタクリロイルオキシアダマンタン（ＨＭＡ）５ｇ、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＭＮＢＬ）５ｇ、２−メタクリロイルオキシ−２−メチルアダマンタン（２−ＭＭＡ）５ｇと、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）０．９３ｇと、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）４１ｇの混合溶液を６時間かけて滴下した。滴下後、２時間熟成した。得られた反応液（ポリマードープ）（３５℃）にメチルイソブチルケトン（ＭＩＢＫ）（３５℃）５４ｇ添加し、得られたポリマー溶液に同重量の水を添加した。この混合物を３５℃で３０分間攪拌した後、３０分間静置して分液させた。下層（水層）を除去した後、上層（有機層）に新たに上層と同量の水を加え、再び３５℃で３０分間攪拌し、３０分間静置し、下層（水層）を除去した。上層（有機層）（３５℃）を孔径０．５μｍのフィルター及び孔径０．１μｍのフィルターに通した後、６５６ｇのヘプタンと２１９ｇの酢酸エチルの混合液（３５℃）中に滴下し、滴下終了後、６０分間攪拌し、９０分間静置することにより沈殿精製を行った。
上澄み液６４０ｇを抜き取り、その残渣にヘプタン６４０ｇを加え、３５℃でリパルプ操作を実施した。リパルプ操作は、ヘプタン仕込後、３０分間攪拌し、９０分間静置し、上澄み液を抜き取ることにより行った。このリパルプ操作を併せて２回実施した。上澄み液を抜き取った後の残渣を遠心分離機に移液し、６００Ｇの遠心力により脱液を行い、湿ポリマーを得た。この湿ポリマーに６５ｇのヘプタンを加え、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。次いで、１００ｇの超純水（Ｎａ分０．９重量ｐｐｂ）を加えて、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。
得られた湿ポリマーを取り出し、棚段乾燥機に入れ、２０ｍｍＨｇ（２．６６ｋＰａ）、７０℃で３０時間乾燥することにより、フォトレジスト用ポリマー（ＡｒＦレジスト樹脂）１０．５ｇが得られた。このフォトレジスト用ポリマーをＰＧＭＥＡ３１．５ｇに溶解させてフォトレジスト用ポリマー溶液を得た。
なお、得られたフォトレジスト用ポリマーの重量平均分子量は８２５０、分子量分布は１．７４であり、金属成分等の含有量（ポリマー重量基準）は、Ｎａ９５重量ｐｐｂ、Ｍｇ４０重量ｐｐｂ、Ｋ４０重量ｐｐｂ、Ｃａ４５重量ｐｐｂ、Ｚｎ４８重量ｐｐｂ、Ｆｅ３８重量ｐｐｂ、Ａｌ２０重量ｐｐｂ、Ｃｒ２０重量ｐｐｂ、Ｍｎ３５重量ｐｐｂ、Ｎｉ２０重量ｐｐｂ、Ｃｕ２０重量ｐｐｂ、残存モノマーＭＮＢＬ０．０５重量％、ＨＭＡ０．０５重量％、２−ＭＭＡ０．０８重量％、残存溶媒２．５重量％、水分０．５重量％であった。また、フォトレジスト用ポリマーのＰＧＭＥＡに対する溶解性も良好であった。 Example 1
Manufacture of polymer compounds for photoresists with the following structure

33 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel, and a nitrogen introduction tube, heated to 75 ° C., and then 1-hydroxy-3-methacryloyl. 5 g of oxyadamantane (HMA), 5 g of 5-methacryloyloxy-2,6-norbornanecarbolactone (MNBL), 5 g of 2-methacryloyloxy-2-methyladamantane (2-MMA), and dimethyl-2,2′-azobis ( 2-methylpropionate) (initiator; Wako Pure Chemical Industries, Ltd., V-601) 0.93 g and propylene glycol monomethyl ether acetate (PGMEA) 41 g mixed solution was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours. 54 g of methyl isobutyl ketone (MIBK) (35 ° C.) was added to the resulting reaction solution (polymer dope) (35 ° C.), and the same weight of water was added to the resulting polymer solution. The mixture was stirred at 35 ° C. for 30 minutes and then allowed to stand for 30 minutes for liquid separation. After removing the lower layer (aqueous layer), the same amount of water as the upper layer was newly added to the upper layer (organic layer), stirred again at 35 ° C. for 30 minutes, and allowed to stand for 30 minutes to remove the lower layer (aqueous layer). . The upper layer (organic layer) (35 ° C) was passed through a filter with a pore size of 0.5 µm and a filter with a pore size of 0.1 µm, and then dropped into a mixed solution (35 ° C) of 656 g of heptane and 219 g of ethyl acetate. Then, precipitation refinement | purification was performed by stirring for 60 minutes and leaving still for 90 minutes.
640 g of the supernatant was extracted, 640 g of heptane was added to the residue, and a repulping operation was performed at 35 ° C. The repulping operation was performed by stirring for 30 minutes after leaving heptane, allowing to stand for 90 minutes, and extracting the supernatant. This repulping operation was performed twice. The residue after removing the supernatant was transferred to a centrifuge, and decanted by a centrifugal force of 600 G to obtain a wet polymer. 65 g of heptane was added to this wet polymer, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution. Next, 100 g of ultrapure water (Na content: 0.9 weight ppb) was added, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution.
The obtained wet polymer was taken out, put into a shelf dryer, and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 10.5 g of a polymer for photoresist (ArF resist resin). This photoresist polymer was dissolved in 31.5 g of PGMEA to obtain a photoresist polymer solution.
The weight average molecular weight of the obtained photoresist polymer was 8250, the molecular weight distribution was 1.74, and the content of metal components and the like (polymer weight basis) was 95 wt ppb for Na, 40 wt ppb for Mg, 40 wt ppb for K, Ca 45 wt ppb, Zn 48 wt ppb, Fe 38 wt ppb, Al 20 wt ppb, Cr 20 wt ppb, Mn 35 wt ppb, Ni 20 wt ppb, Cu 20 wt ppb, residual monomer MNBL 0.05 wt%, HMA 0.05 wt%, 2-MMA 0. It was 08% by weight, residual solvent 2.5% by weight, and water 0.5% by weight. The solubility of the photoresist polymer in PGMEA was also good.

Example 2
In the same manner as in Example 1, reaction (polymerization), water washing (extraction), filtration, and precipitation purification were performed. Subsequently, 640 g of the supernatant liquid during precipitation purification was extracted, and the residue was transferred to a centrifuge, and the liquid was removed by a centrifugal force of 600 G to obtain a wet polymer. 65 g of heptane was added to this wet polymer, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution. Next, 100 g of ultrapure water (Na content: 0.9 weight ppb) was added, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution.
The obtained wet polymer (42 g) was dissolved in 63 g of methyl amyl ketone. By concentrating this solution (normal pressure to 2.66 kPa; room temperature to 75 ° C.), 42 g of a 25 wt% photoresist polymer solution was obtained.
The weight average molecular weight of the obtained photoresist polymer is 8200, the molecular weight distribution is 1.75, and the content of metal components and the like (polymer weight basis) is Na 94 wt ppb, Mg 30 wt ppb, K 35 wt ppb, Ca 40 wt ppb, Zn 50 wt ppb, Fe 42 wt ppb, Al 20 wt ppb, Cr 20 wt ppb, Mn 5 wt ppb, Ni 5 wt ppb, Cu 10 wt ppb, residual monomer MNBL 0.09 wt%, HMA 0.09 wt%, 2-MMA 0. It was 11% by weight.

Comparative Example 1
Except that the washing (extraction) operation was not performed, the same operation as in Example 2 was performed to obtain a photoresist polymer solution. The content of the metal component in the obtained photoresist polymer (polymer weight basis) was Na 550 wt ppb, Mg 80 wt ppb, K 240 wt ppb, Ca 300 wt ppb, Zn 250 wt ppb, Fe 300 wt ppb, Al 200 wt ppb, Cr 80 Weight ppb, Mn 30 weight ppb, Ni 30 weight ppb, Cu 40 weight ppb.

Example 3
Reaction (polymerization) was carried out in the same manner as in Example 1. The obtained reaction solution (polymer dope) (35 ° C.) was passed through a filter with a pore size of 0.5 μm and a filter with a pore size of 0.1 μm, and then dropped into a mixed solution (35 ° C.) of 656 g of heptane and 219 g of ethyl acetate. Then, after completion of the dropwise addition, the mixture was stirred for 60 minutes and allowed to stand for 90 minutes for precipitation purification. The residue after removing the supernatant liquid during precipitation purification was transferred to a centrifuge, and the liquid was removed by centrifugal force of 600 G to obtain a wet polymer. 63 g of methyl amyl ketone (MAK) was added to the wet polymer and dissolved at 60 ° C. The same weight of water was added to the resulting polymer solution. The mixture was stirred at 35 ° C. for 30 minutes and then allowed to stand for 30 minutes for liquid separation. After removing the lower layer (aqueous layer), the same amount of water as the upper layer was newly added to the upper layer (organic layer), stirred again at 35 ° C. for 30 minutes, and allowed to stand for 30 minutes to remove the lower layer (aqueous layer). . The upper layer (organic layer) was concentrated (normal pressure to 2.66 kPa; room temperature to 75 ° C.) to obtain 42 g of a photoresist polymer solution of 25 wt%.
The weight average molecular weight of the obtained photoresist polymer is 8280, the molecular weight distribution is 1.76, and the content of metal components and the like (polymer weight basis) is Na 85 wt ppb, Mg 25 wt ppb, K 30 wt ppb, Ca 35 wt ppb, Zn 45 wt ppb, Fe 40 wt ppb, Al 15 wt ppb, Cr 15 wt ppb, Mn 5 wt ppb, Ni 5 wt ppb, Cu 10 wt ppb, residual monomer MNBL 0.09 wt%, HMA 0.08 wt%, 2-MMA 0. It was 10% by weight.

攪拌機、温度計、還流冷却管、滴下ロート及び窒素導入管を備えたセパラブルフラスコに、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を１２．０ｇ導入し、７５℃に昇温後、１−アクリロイルオキシ−３−ヒドロキシアダマンタン（ＨＡＡ）３．３７ｇ、５−アクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＡＮＢＬ）３．６０ｇ、１−（１−アクリロイルオキシ−１−メチルエチル）アダマンタン（ＩＡＡ）８．０３ｇと、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）０．８５ｇと、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）４８ｇの混合溶液を６時間かけて滴下した。滴下後、２時間熟成した。得られた反応液（ポリマードープ）（３０℃）を孔径０．５μｍのフィルターに通した後、これにメチルイソブチルケトン（ＭＩＢＫ）（３０℃）７５ｇ添加し、得られたポリマー溶液に同重量の水を添加した。この混合物を３０℃で３０分間攪拌した後、３０分間静置して分液させた。下層（水層）を除去した後、上層（有機層）に新たに上層と同量の水を加え、再び３０℃で３０分間攪拌し、３０分間静置し、下層（水層）を除去した。上層（有機層）（３０℃）を孔径０．１μｍのフィルターに通した後、８３２ｇのヘプタンと９２ｇの酢酸エチルの混合液（３０℃）中に滴下し、滴下終了後、６０分間攪拌することにより沈殿精製を行った。
これを遠心分離機に移液し、６００Ｇの遠心力により脱液を行い、湿ポリマーを得た。この湿ポリマーに１１６ｇのヘプタンを加え、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。次いで、１１６ｇの超純水（Ｎａ分０．１重量ｐｐｂ）を加えて、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。
得られた湿ポリマーを取り出し、棚段乾燥機に入れ、２０ｍｍＨｇ（２．６６ｋＰａ）、４５℃で６５時間乾燥することにより、フォトレジスト用ポリマー（ＡｒＦレジスト樹脂）１２ｇが得られた。このフォトレジスト用ポリマーをＰＧＭＥＡ３６ｇに溶解させてフォトレジスト用ポリマー溶液を得た。
なお、得られたフォトレジスト用ポリマーの重量平均分子量は１５０００、分子量分布は２．５０であり、Ｎａ含量（ポリマー重量基準）は７０重量ｐｐｂであった。また、フォトレジスト用ポリマーのＰＧＭＥＡに対する溶解性も良好であった。 Example 4
Manufacture of polymer compounds for photoresists with the following structure

12.0 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube, heated to 75 ° C., and then 1-acryloyloxy- 3-hydroxyadamantane (HAA) 3.37 g, 5-acryloyloxy-2,6-norbornanecarbolactone (ANBL) 3.60 g, 1- (1-acryloyloxy-1-methylethyl) adamantane (IAA) 8.03 g And a mixed solution of 0.85 g of dimethyl-2,2′-azobis (2-methylpropionate) (initiator; W-601, V-601) and 48 g of propylene glycol monomethyl ether acetate (PGMEA) It was dripped over 6 hours. After dropping, the mixture was aged for 2 hours. The obtained reaction solution (polymer dope) (30 ° C.) was passed through a filter having a pore size of 0.5 μm, and 75 g of methyl isobutyl ketone (MIBK) (30 ° C.) was added thereto, and the same weight was added to the obtained polymer solution. Water was added. The mixture was stirred at 30 ° C. for 30 minutes and then allowed to stand for 30 minutes for liquid separation. After removing the lower layer (aqueous layer), the same amount of water as the upper layer was newly added to the upper layer (organic layer), stirred again at 30 ° C. for 30 minutes, and allowed to stand for 30 minutes to remove the lower layer (aqueous layer). . The upper layer (organic layer) (30 ° C.) is passed through a filter having a pore size of 0.1 μm, and then dropped into a mixed solution (30 ° C.) of 832 g of heptane and 92 g of ethyl acetate. The precipitate was purified by
This was transferred to a centrifuge and drained by a centrifugal force of 600 G to obtain a wet polymer. 116 g of heptane was added to the wet polymer, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution. Next, 116 g of ultrapure water (Na content: 0.1 wt ppb) was added, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution.
The obtained wet polymer was taken out, put into a shelf dryer, and dried at 20 mmHg (2.66 kPa) and 45 ° C. for 65 hours to obtain 12 g of a photoresist polymer (ArF resist resin). The photoresist polymer was dissolved in 36 g of PGMEA to obtain a photoresist polymer solution.
The resulting photoresist polymer had a weight average molecular weight of 15,000, a molecular weight distribution of 2.50, and an Na content (based on polymer weight) of 70 weight ppb. The solubility of the photoresist polymer in PGMEA was also good.

Example 5
In the same manner as in Example 4, reaction (polymerization), water washing (extraction), filtration, precipitation purification, and rinsing operation were performed. The obtained wet polymer (24 g) was dissolved in 96 g of PGMEA. By concentrating this solution (normal pressure to 8 kPa; room temperature to 80 ° C.), 48 g of a 25 wt% photoresist polymer solution was obtained.
The resulting photoresist polymer had a weight average molecular weight of 14,800, a molecular weight distribution of 2.45, and an Na content (based on polymer weight) of 65 weight ppb.

Comparative Example 2
Except that the washing (extraction) operation was not performed, the same operation as in Example 5 was performed to obtain a photoresist polymer solution. The content of the metal component (polymer weight basis) in the obtained photoresist polymer was Na 500 wt ppb, Mg 70 wt ppb, K 150 wt ppb, Ca 480 wt ppb, Zn 840 wt ppb, Fe 150 wt ppb, Al 80 wt ppb, Cr 70 Weight ppb, Mn 40 weight ppb, Ni 40 weight ppb, Cu 40 weight ppb.

攪拌機、温度計、還流冷却管、滴下ロート及び窒素導入管を備えたセパラブルフラスコに、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）２３．６ｇ及びプロピレングリコールモノメチルエーテル（ＰＧＭＥ）１０．１ｇを導入し、１００℃に昇温後、１，３−ジヒドロキシ−５−メタクリロイルオキシアダマンタン（ＤＨＭＡ）２．７２ｇ、５−アクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＡＮＢＬ）６．７４ｇ、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン（ＩＡＭ）７．５４ｇと、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）０．１５ｇと、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）４３．８ｇ及びプロピレングリコールモノメチルエーテル（ＰＧＭＥ）１８．８ｇの混合溶液を６時間かけて滴下した。滴下後、２時間熟成した。得られた反応液（ポリマードープ）（３５℃）を孔径０．５μｍのフィルターに通した後、これにメチルイソブチルケトン（ＭＩＢＫ）（３５℃）５６．７ｇ添加し、得られたポリマー溶液に１／２重量の水を添加した。この混合物を３５℃で３０分間攪拌した後、３０分間静置して分液させた。下層（水層）を除去した後、上層（有機層）に新たに上層の１／２重量の水を加え、再び３５℃で３０分間攪拌し、３０分間静置し、下層（水層）を除去した。上層（有機層）（３５℃）を孔径０．１μｍのフィルターに通した後、９１３．５ｇのヘプタンと１３６．５ｇの酢酸エチルの混合液（３５℃）中に滴下し、滴下終了後、３０分間攪拌することにより沈殿精製を行った。
これを遠心分離機に移液し、６００Ｇの遠心力により脱液を行い、湿ポリマーを得た。この湿ポリマーに２１０ｇのヘプタンを加え、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。次いで、２１０ｇの超純水（Ｎａ分０．８重量ｐｐｂ）を加えて、６００Ｇの遠心力によりリンスを行い、リンス液を除去した。
得られた湿ポリマーを取り出し、棚段乾燥機に入れ、２０ｍｍＨｇ（２．６６ｋＰａ）、４５℃で４０時間乾燥することにより、フォトレジスト用ポリマー（ＡｒＦレジスト樹脂）１４ｇが得られた。このフォトレジスト用ポリマーをＰＧＭＥＡ２９ｇ及びＰＧＭＥ１３ｇの混合溶媒に溶解させてフォトレジスト用ポリマー溶液を得た。
なお、得られたフォトレジスト用ポリマーの重量平均分子量は９７００、分子量分布は２．１４であり、Ｎａ含量（ポリマー重量基準）は５０重量ｐｐｂであった。また、フォトレジスト用ポリマーのＰＧＭＥＡ／ＰＧＭＥ［＝７／３（重量比）］混合溶媒に対する溶解性も良好であった。 Example 6
Manufacture of polymer compounds for photoresists with the following structure

Into a separable flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introducing tube, 23.6 g of propylene glycol monomethyl ether acetate (PGMEA) and 10.1 g of propylene glycol monomethyl ether (PGME) were introduced, and 100 After raising the temperature to ° C., 1,3-dihydroxy-5-methacryloyloxyadamantane (DHMA) 2.72 g, 5-acryloyloxy-2,6-norbornanecarbolactone (ANBL) 6.74 g, 1- (1-methacryloyloxy -1-methylethyl) adamantane (IAM) 7.54 g, dimethyl-2,2'-azobis (2-methylpropionate) (initiator; W-601, V-601) 0.15 g, Propylene glycol monomethyl ether acetate (PGMEA) The 3.8g and propylene glycol monomethyl ether (PGME) mixed solution of 18.8g was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours. The obtained reaction solution (polymer dope) (35 ° C.) was passed through a filter having a pore size of 0.5 μm, and then 56.7 g of methyl isobutyl ketone (MIBK) (35 ° C.) was added thereto. / 2 weight of water was added. The mixture was stirred at 35 ° C. for 30 minutes and then allowed to stand for 30 minutes for liquid separation. After removing the lower layer (aqueous layer), ½ weight of water of the upper layer was newly added to the upper layer (organic layer), stirred again at 35 ° C. for 30 minutes, allowed to stand for 30 minutes, and the lower layer (aqueous layer) was Removed. The upper layer (organic layer) (35 ° C.) was passed through a filter having a pore size of 0.1 μm, and then dropped into a mixed solution (35 ° C.) of 913.5 g of heptane and 136.5 g of ethyl acetate. Precipitation purification was performed by stirring for minutes.
This was transferred to a centrifuge and drained by a centrifugal force of 600 G to obtain a wet polymer. 210 g of heptane was added to the wet polymer, and rinsing was performed with a centrifugal force of 600 G to remove the rinse solution. Next, 210 g of ultrapure water (Na content: 0.8 wt ppb) was added and rinsed by a centrifugal force of 600 G to remove the rinse solution.
The obtained wet polymer was taken out, put into a shelf dryer, and dried at 20 mmHg (2.66 kPa) and 45 ° C. for 40 hours to obtain 14 g of a photoresist polymer (ArF resist resin). This photoresist polymer was dissolved in a mixed solvent of 29 g of PGMEA and 13 g of PGME to obtain a photoresist polymer solution.
The obtained photoresist polymer had a weight average molecular weight of 9700, a molecular weight distribution of 2.14, and an Na content (based on polymer weight) of 50 wt ppb. Moreover, the solubility with respect to the PGMEA / PGME [= 7/3 (weight ratio)] mixed solvent of the polymer for photoresists was also favorable.

Example 7
In the same manner as in Example 6, reaction (polymerization), water washing (extraction), filtration, precipitation purification, and rinsing operation were performed. The obtained wet polymer (42 g) was dissolved in 98 g of a PGMEA / PGME mixed solvent [= 7/3 (weight ratio)]. By concentrating this solution (normal pressure to 8 kPa; room temperature to 70 ° C.), 56 g of a 25 wt% photoresist polymer solution was obtained.
The resulting photoresist polymer had a weight average molecular weight of 9750, a molecular weight distribution of 2.12, and an Na content (based on polymer weight) of 48 weight ppb.

Comparative Example 3
Except that the washing (extraction) operation was not performed, the same operation as in Example 7 was performed to obtain a polymer solution for photoresist. The content of the metal component (polymer weight basis) in the obtained photoresist polymer is Na 800 wt ppb, Mg 70 wt ppb, K 140 wt ppb, Ca 150 wt ppb, Zn 190 wt ppb, Fe 140 wt ppb, Al 90 wt ppb, Cr 70 Weight ppb, Mn 30 weight ppb, Ni 30 weight ppb, Cu 30 weight ppb.

Example 8
In Example 1, 2,2 ′ instead of 0.93 g of dimethyl-2,2′-azobis (2-methylpropionate) (initiator; manufactured by Wako Pure Chemical Industries, Ltd., V-601) as a polymerization initiator -1.16 g of azobis [2-methyl-N- (2-hydroxyethyl) propionamide] (initiator; manufactured by Wako Pure Chemical Industries, Ltd., VA-086), propylene glycol monomethyl ether acetate which is a solvent which is initially put into a flask (PGMEA) 41 g of ethyl lactate instead of 33 g, and the same operation as in Example 1 except that 41 g of ethyl lactate was used instead of 41 g of propylene glycol monomethyl ether acetate (PGMEA) as the solvent of the mixed solution to be dropped. 10.2 g of resist polymer (ArF resist resin) was obtained. Further, using this polymer, a polymer solution for photoresist was obtained in the same manner as in Example 1.
The weight average molecular weight of the obtained photoresist polymer was 8350, the molecular weight distribution was 1.80, and the content of metal components and the like (polymer weight basis) was Na 85 wt ppb, Mg 43 wt ppb, K 30 wt ppb, Ca 50 wt ppb, Zn 44 wt ppb, Fe 30 wt ppb, Al 15 wt ppb, Cr 20 wt ppb, Mn 30 wt ppb, Ni 25 wt ppb, Cu 20 wt ppb, residual monomer MNBL 0.05 wt%, HMA 0.05 wt%, 2-MMA 0. The remaining solvent was 2.5% by weight, and the water content was 0.5% by weight. The solubility of the photoresist polymer in PGMEA was also good.

Example 9
In Example 4, 2,2 ′ instead of 0.85 g of dimethyl-2,2′-azobis (2-methylpropionate) (initiator; W-601 manufactured by Wako Pure Chemical Industries, Ltd.), which is a polymerization initiator, was used. -1.16 g of azobis [2-methyl-N- (2-hydroxyethyl) propionamide] (initiator; manufactured by Wako Pure Chemical Industries, Ltd., VA-086), propylene glycol monomethyl ether acetate which is a solvent which is initially put into a flask (PGMEA) The same operation as in Example 4 except that 12.0 g of ethyl lactate was used and 12.0 g of ethyl lactate was used, and 48 g of ethyl lactate was used instead of 48 g of propylene glycol monomethyl ether acetate (PGMEA) as a solvent of the mixed solution to be dropped. 11.5 g of a polymer for photoresist (ArF resist resin) was obtained. Further, using this polymer, a polymer solution for photoresist was obtained in the same manner as in Example 4.
The resulting photoresist polymer had a weight average molecular weight of 14,500, a molecular weight distribution of 2.35, and an Na content (based on polymer weight) of 60 wt ppb. The solubility of the photoresist polymer in PGMEA was also good.

Example 10
In Example 6, 2,2 ′ instead of 0.15 g of dimethyl-2,2′-azobis (2-methylpropionate) (initiator; manufactured by Wako Pure Chemical Industries, Ltd., V-601) as a polymerization initiator -0.19 g of azobis [2-methyl-N- (2-hydroxyethyl) propionamide] (initiator; VA-086 manufactured by Wako Pure Chemical Industries, Ltd.), propylene glycol monomethyl ether acetate which is a solvent which is initially put into the flask (PGMEA) 23.6 g and propylene glycol monomethyl ether (PGME) 10.1 g instead of ethyl lactate 33.7 g, propylene glycol monomethyl ether acetate (PGMEA) 43.8 g and propylene glycol monomethyl ether as a solvent of the mixed solution to be dropped (PGME) Instead of 18.8 g, ethyl lactate 62.6 Except for using the following the procedure of Example 6, to obtain a photoresist polymer (ArF resist resin) 12.8 g. Further, using this polymer, a polymer solution for photoresist was obtained in the same manner as in Example 6.
The resulting photoresist polymer had a weight average molecular weight of 10,500, a molecular weight distribution of 2.20, and an Na content (based on polymer weight) of 55 weight ppb. Moreover, the solubility with respect to the PGMEA / PGME [= 7/3 (weight ratio)] mixed solvent of the polymer for photoresists was also favorable.

攪拌機、温度計、還流冷却管、滴下管及び窒素導入管を備えた反応器に、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を７０ｇ導入し、１００℃に昇温後、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＭＮＢＬ）（金属含有量１００ｐｐｂ以下）７３．０ｇ、２−メタクリロイルオキシ−２−メチルアダマンタン（２−ＭＭＡ）７７．０ｇ、アゾビスイソブチロニトリル１．８ｇ及びＰＧＭＥＡ５３０ｇの混合溶液を６時間かけて滴下した。滴下後２時間熟成し、上記式で表される高分子化合物を２０重量％含有するポリマー溶液を得た。このポリマー溶液を孔径０．５μｍのメンブランフィルターに通した後、メチルイソブチルケトン（ＭＩＢＫ）７５０ｇを添加した。この時のポリマー溶液中の金属含有量は４５０ｐｐｂであった。
このポリマー溶液を、カチオン交換基を有する多孔質ポリオレフィン膜で構成された「イオンクリーン」（商品名）（日本ポール（株）製、材質：化学修飾タイプ超高分子量ポリエチレン、濾過面積：０．１１ｍ²）に、室温で１００ｇ／ｍｉｎの流速で通液した。
得られた溶液を、ヘキサン６７５０ｇと酢酸エチル２２５０ｇの混合溶媒中に落とし、生じた沈殿物をヘキサン６５００ｇでリパルプした。上澄み液を除去し、残渣を遠心分離機に移液し、脱液して湿ポリマーを得た。得られた湿ポリマーを取り出し、２０ｍｍＨｇ（２．６６ｋＰａ）、７０℃で３０時間乾燥することにより、製品ポリマーを１０８ｇ得た。製品ポリマー中の金属含有量は５０ｐｐｂであった。 Example 11
Manufacture of polymer compounds for photoresists with the following structure

70 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a dropping pipe and a nitrogen introduction pipe, heated to 100 ° C., and then 5-methacryloyloxy-2,6 -A mixed solution of 73.0 g of norbornanecarbolactone (MNBL) (metal content of 100 ppb or less), 77.0 g of 2-methacryloyloxy-2-methyladamantane (2-MMA), 1.8 g of azobisisobutyronitrile and 530 g of PGMEA Was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours to obtain a polymer solution containing 20% by weight of the polymer compound represented by the above formula. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 450 ppb.
“Ion Clean” (trade name) (made by Nippon Pole Co., Ltd., material: chemically modified type ultrahigh molecular weight polyethylene, filtration area: 0.11 m, made of this polymer solution with a porous polyolefin membrane having a cation exchange group ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 108 g of a product polymer. The metal content in the product polymer was 50 ppb.

Comparative Example 4
Polymerization was performed in the same manner as in Example 11 except that a commercially available product was used as PGMEA as it was to obtain a polymer solution. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of commercially available methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
“Ion Clean” (trade name) (made by Nippon Pole Co., Ltd., material: chemically modified type ultrahigh molecular weight polyethylene, filtration area: 0.11 m, made of this polymer solution with a porous polyolefin membrane having a cation exchange group ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 105 g of a product polymer. The metal content in the product polymer was 70 ppb.

Example 12
Polymerization was performed in the same manner as in Example 11 except that a commercially available product was used as PGMEA as it was to obtain a polymer solution. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of commercially available methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
Water washing operation was performed by adding 1500 g of water (ultra pure water) to the polymer solution, stirring and separating the solution. The metal content in the obtained organic layer was 250 ppb. This organic layer is made of a porous polyolefin membrane having a cation exchange group, “Ion Clean” (trade name) (manufactured by Nippon Pole Co., Ltd., material: chemically modified ultra-high molecular weight polyethylene, filtration area: 0.11 m ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 105 g of a product polymer. The metal content in the product polymer was 60 ppb.

Comparative Example 5
Polymerization was performed in the same manner as in Example 11 except that a commercially available product was used as PGMEA as it was to obtain a polymer solution. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of commercially available methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
Water washing operation was performed by adding 1500 g of water (ultra pure water) to the polymer solution, stirring and separating the solution. The metal content in the obtained organic layer was 250 ppb.
This organic layer (polymer solution) was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate without passing through the porous polyolefin membrane, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 103 g of a product polymer. The metal content in the product polymer was 250 ppb.

攪拌機、温度計、還流冷却管、滴下管及び窒素導入管を備えた反応器に、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を７０ｇ導入し、１００℃に昇温後、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＭＮＢＬ）（金属含有量１００ｐｐｂ以下）５０ｇ、２−メタクリロイルオキシ−２−メチルアダマンタン（２−ＭＭＡ）５０ｇ、１−ヒドロキシ−３−メタクリロイルオキシアダマンタン（ＨＭＡ）５０ｇ、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）１．８ｇ及びＰＧＭＥＡ５３０ｇの混合溶液を６時間かけて滴下した。滴下後２時間熟成し、上記式で表される高分子化合物を２０重量％含有するポリマー溶液を得た。このポリマー溶液を孔径０．５μｍのメンブランフィルターに通した後、メチルイソブチルケトン（ＭＩＢＫ）７５０ｇを添加した。この時のポリマー溶液中の金属含有量は１２００ｐｐｂであった。
このポリマー溶液に水（超純水）１５００ｇを加えて攪拌、分液することにより水洗操作を行った。得られた有機層中の金属含有量は２５０ｐｐｂであった。この有機層を、カチオン交換基を有する多孔質ポリオレフィン膜で構成された「イオンクリーン」（商品名）（日本ポール（株）製、材質：化学修飾タイプ超高分子量ポリエチレン、濾過面積：０．１１ｍ²）に、室温で１００ｇ／ｍｉｎの流速で通液した。
得られた溶液を、ヘキサン６７５０ｇと酢酸エチル２２５０ｇの混合溶媒中に落とし、生じた沈殿物をヘキサン６５００ｇでリパルプした。上澄み液を除去し、残渣を遠心分離機に移液し、脱液して湿ポリマーを得た。得られた湿ポリマーを取り出し、２０ｍｍＨｇ（２．６６ｋＰａ）、７０℃で３０時間乾燥することにより、製品ポリマーを１０５ｇ得た。製品ポリマー中の金属含有量は５０ｐｐｂであった。 Example 13
Manufacture of polymer compounds for photoresists with the following structure

70 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a dropping pipe and a nitrogen introduction pipe, heated to 100 ° C., and then 5-methacryloyloxy-2,6 -50 g of norbornane carbolactone (MNBL) (metal content of 100 ppb or less), 50 g of 2-methacryloyloxy-2-methyladamantane (2-MMA), 50 g of 1-hydroxy-3-methacryloyloxyadamantane (HMA), dimethyl-2, A mixed solution of 1.8 g of 2′-azobis (2-methylpropionate) (initiator: Wako Pure Chemical Industries, V-601) and 530 g of PGMEA was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours to obtain a polymer solution containing 20% by weight of the polymer compound represented by the above formula. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
Water washing operation was performed by adding 1500 g of water (ultra pure water) to the polymer solution, stirring and separating the solution. The metal content in the obtained organic layer was 250 ppb. This organic layer is made of a porous polyolefin membrane having a cation exchange group, “Ion Clean” (trade name) (manufactured by Nippon Pole Co., Ltd., material: chemically modified ultra-high molecular weight polyethylene, filtration area: 0.11 m ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 105 g of a product polymer. The metal content in the product polymer was 50 ppb.

Comparative Example 6
Polymerization was performed in the same manner as in Example 13 to obtain a polymer solution. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of commercially available methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
“Ion Clean” (trade name) (made by Nippon Pole Co., Ltd., material: chemically modified type ultrahigh molecular weight polyethylene, filtration area: 0.11 m, made of this polymer solution with a porous polyolefin membrane having a cation exchange group ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 108 g of a product polymer. The metal content in the product polymer was 70 ppb.

攪拌機、温度計、還流冷却管、滴下管及び窒素導入管を備えた反応器に、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を７０ｇ導入し、１００℃に昇温後、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＭＮＢＬ）（金属含有量１００ｐｐｂ以下）５０ｇ、２−メタクリロイルオキシ−２−メチルアダマンタン（２−ＭＭＡ）５０ｇ、１，３−ジヒドロキシ−５−メタクリロイルオキシアダマンタン（ＤＨＭＡ）５０ｇ、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）１．８ｇ及びＰＧＭＥＡ５３０ｇの混合溶液を６時間かけて滴下した。滴下後２時間熟成し、上記式で表される高分子化合物を２０重量％含有するポリマー溶液を得た。このポリマー溶液を孔径０．５μｍのメンブランフィルターに通した後、メチルイソブチルケトン（ＭＩＢＫ）７５０ｇを添加した。この時のポリマー溶液中の金属含有量は１２００ｐｐｂであった。
このポリマー溶液に水（超純水）１５００ｇを加えて攪拌、分液することにより水洗操作を行った。得られた有機層中の金属含有量は２５０ｐｐｂであった。この有機層を、カチオン交換基を有する多孔質ポリオレフィン膜で構成された「イオンクリーン」（商品名）（日本ポール（株）製、材質：化学修飾タイプ超高分子量ポリエチレン、濾過面積：０．１１ｍ²）に、室温で１００ｇ／ｍｉｎの流速で通液した。
得られた溶液を、ヘキサン６７５０ｇと酢酸エチル２２５０ｇの混合溶媒中に落とし、生じた沈殿物をヘキサン６５００ｇでリパルプした。上澄み液を除去し、残渣を遠心分離機に移液し、脱液して湿ポリマーを得た。得られた湿ポリマーを取り出し、２０ｍｍＨｇ（２．６６ｋＰａ）、７０℃で３０時間乾燥することにより、製品ポリマーを１０５ｇ得た。製品ポリマー中の金属含有量は５０ｐｐｂであった。 Example 14
Manufacture of polymer compounds for photoresists with the following structure

70 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a dropping pipe and a nitrogen introduction pipe, heated to 100 ° C., and then 5-methacryloyloxy-2,6 -50 g of norbornanecarbolactone (MNBL) (metal content of 100 ppb or less), 50 g of 2-methacryloyloxy-2-methyladamantane (2-MMA), 50 g of 1,3-dihydroxy-5-methacryloyloxyadamantane (DHMA), dimethyl- A mixed solution of 1.8 g of 2,2′-azobis (2-methylpropionate) (initiator; manufactured by Wako Pure Chemical Industries, V-601) and 530 g of PGMEA was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours to obtain a polymer solution containing 20% by weight of the polymer compound represented by the above formula. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
Water washing operation was performed by adding 1500 g of water (ultra pure water) to the polymer solution, stirring and separating the solution. The metal content in the obtained organic layer was 250 ppb. This organic layer is made of a porous polyolefin membrane having a cation exchange group, “Ion Clean” (trade name) (manufactured by Nippon Pole Co., Ltd., material: chemically modified ultra-high molecular weight polyethylene, filtration area: 0.11 m ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 105 g of a product polymer. The metal content in the product polymer was 50 ppb.

攪拌機、温度計、還流冷却管、滴下管及び窒素導入管を備えた反応器に、プロピレングリコールモノメチルエーテルアセテート（ＰＧＭＥＡ）を７０ｇ導入し、１００℃に昇温後、５−メタクリロイルオキシ−２，６−ノルボルナンカルボラクトン（ＭＮＢＬ）（金属含有量１００ｐｐｂ以下）５０ｇ、１−（１−メタクリロイルオキシ−１−メチルエチル）アダマンタン（ＩＡＭ）５０ｇ、１−ヒドロキシ−３−メタクリロイルオキシアダマンタン（ＨＭＡ）５０ｇ、ジメチル−２，２′−アゾビス（２−メチルプロピオネート）（開始剤；和光純薬工業製、Ｖ−６０１）１．８ｇ及びＰＧＭＥＡ５３０ｇの混合溶液を６時間かけて滴下した。滴下後２時間熟成し、上記式で表される高分子化合物を２０重量％含有するポリマー溶液を得た。このポリマー溶液を孔径０．５μｍのメンブランフィルターに通した後、メチルイソブチルケトン（ＭＩＢＫ）７５０ｇを添加した。この時のポリマー溶液中の金属含有量は１２００ｐｐｂであった。
このポリマー溶液に水（超純水）１５００ｇを加えて攪拌、分液することにより水洗操作を行った。得られた有機層中の金属含有量は２５０ｐｐｂであった。この有機層を、カチオン交換基を有する多孔質ポリオレフィン膜で構成された「イオンクリーン」（商品名）（日本ポール（株）製、材質：化学修飾タイプ超高分子量ポリエチレン、濾過面積：０．１１ｍ²）に、室温で１００ｇ／ｍｉｎの流速で通液した。
得られた溶液を、ヘキサン６７５０ｇと酢酸エチル２２５０ｇの混合溶媒中に落とし、生じた沈殿物をヘキサン６５００ｇでリパルプした。上澄み液を除去し、残渣を遠心分離機に移液し、脱液して湿ポリマーを得た。得られた湿ポリマーを取り出し、２０ｍｍＨｇ（２．６６ｋＰａ）、７０℃で３０時間乾燥することにより、製品ポリマーを１０５ｇ得た。製品ポリマー中の金属含有量は５０ｐｐｂであった。 Example 15
Manufacture of polymer compounds for photoresists with the following structure

70 g of propylene glycol monomethyl ether acetate (PGMEA) was introduced into a reactor equipped with a stirrer, a thermometer, a reflux condenser, a dropping pipe and a nitrogen introduction pipe, heated to 100 ° C., and then 5-methacryloyloxy-2,6 -50 g of norbornanecarbolactone (MNBL) (metal content of 100 ppb or less), 50 g of 1- (1-methacryloyloxy-1-methylethyl) adamantane (IAM), 50 g of 1-hydroxy-3-methacryloyloxyadamantane (HMA), dimethyl A mixed solution of 1.8 g of -2,2'-azobis (2-methylpropionate) (initiator; manufactured by Wako Pure Chemical Industries, Ltd., V-601) and 530 g of PGMEA was added dropwise over 6 hours. After dropping, the mixture was aged for 2 hours to obtain a polymer solution containing 20% by weight of the polymer compound represented by the above formula. This polymer solution was passed through a membrane filter having a pore size of 0.5 μm, and then 750 g of methyl isobutyl ketone (MIBK) was added. The metal content in the polymer solution at this time was 1200 ppb.
Water washing operation was performed by adding 1500 g of water (ultra pure water) to the polymer solution, stirring and separating the solution. The metal content in the obtained organic layer was 250 ppb. This organic layer is made of a porous polyolefin membrane having a cation exchange group, “Ion Clean” (trade name) (manufactured by Nippon Pole Co., Ltd., material: chemically modified ultra-high molecular weight polyethylene, filtration area: 0.11 m ² ) was passed at a flow rate of 100 g / min at room temperature.
The obtained solution was dropped into a mixed solvent of 6750 g of hexane and 2250 g of ethyl acetate, and the resulting precipitate was repulped with 6500 g of hexane. The supernatant was removed and the residue was transferred to a centrifuge and drained to obtain a wet polymer. The obtained wet polymer was taken out and dried at 20 mmHg (2.66 kPa) and 70 ° C. for 30 hours to obtain 105 g of a product polymer. The metal content in the product polymer was 50 ppb.

Evaluation Test 100 parts by weight of each polymer obtained in Examples 11 to 15 and Comparative Examples 4 to 6 and 10 parts by weight of triphenylsulfonium hexafluoroantimonate were dissolved in ethyl lactate, and used for a photoresist having a polymer concentration of 20% by weight. A resin composition was prepared. This photoresist resin composition was applied to a silicon wafer by spin coating to form a photosensitive layer having a thickness of 1.0 μm. After pre-baking on a hot plate at a temperature of 110 ° C. for 120 seconds, using a KrF excimer laser with a wavelength of 247 nm, exposure was performed at a dose of 30 mJ / cm ² through a mask, and then post-baking was performed at a temperature of 120 ° C. for 60 seconds. Next, development was carried out with a 0.3 M aqueous solution of tetramethylammonium hydroxide for 60 seconds, followed by rinsing with pure water.
As a result, when the polymers of Examples 11 to 15 were used, a 0.30 μm line and space was obtained. On the other hand, when the polymers of Comparative Examples 4 and 6 were used, only a collapsed pattern was obtained due to the influence of hydrogen ions (acid) generated during the passage of “ion clean”. In addition, when the polymer of Comparative Example 5 was used, a line and space equivalent to that of the Example was obtained, but the electrical characteristics of the semiconductor were poor because of the high metal content.

Claims (25)

  Selected from a monomer (a) containing a lactone skeleton, a monomer (b) containing a group which becomes alkali-soluble upon removal by an acid, and a monomer (c) containing an alicyclic skeleton having a hydroxyl group A photoresist polymer compound obtained by subjecting a monomer mixture containing at least one monomer to drop polymerization, wherein (i) the polymer produced by the drop polymerization is an organic solvent and water The extraction step (B) in which the produced polymer is distributed to the organic solvent layer, and the metal component as an impurity is distributed to the aqueous layer, or (ii) the polymer produced by the dropping polymerization, And passing through a step (I) of passing a polymer solution having a metal content of 1000 ppb or less with respect to the polymer through a filter composed of a porous polyolefin membrane having a cation exchange group. , Photoresist polymeric compound sodium content (polymer weight) is reduced to less than 95 weight ppb.   2. The high molecular weight compound for photoresists according to claim 1, wherein the molecular weight distribution is in the range of 1.74 to 2.50. The monomer (a) containing a lactone skeleton is represented by the following formula (1a), (1b) or (1c)

(In the formula, R ¹ represents a group containing a (meth) acryloyloxy group, R ² , R ³ and R ⁴ are each a lower alkyl group, n is an integer of 0 to 3, and m is an integer of 0 to 5. )
The high molecular compound for photoresists of Claim 1 which is a (meth) acrylic acid ester monomer represented by these. The monomer (b) containing a group that is eliminated by an acid and becomes alkali-soluble is represented by the following formula (2a) or (2b):

(Wherein R is a hydrogen atom or a methyl group, R ⁵ is a hydrogen atom or a lower alkyl group, R ⁶ , R ⁷ , R ⁸ and R ⁹ are each a lower alkyl group, and n is an integer of 0 to 3)
The high molecular compound for photoresists of Claim 1 which is a (meth) acrylic acid ester monomer represented by these. The monomer (c) containing an alicyclic skeleton having a hydroxyl group is represented by the following formula (3a)

(In the formula, R represents a hydrogen atom or a methyl group, R ¹⁰ represents a methyl group, a hydroxyl group, an oxo group or a carboxyl group. K represents an integer of 1 to 3. At least one of k R ^{10 s} ) One is a hydroxyl group)
The high molecular compound for photoresists of Claim 1 which is a (meth) acrylic acid ester monomer represented by these.   The polymer compound for photoresists according to any one of claims 1 to 5, wherein the polymerization solvent in the drop polymerization is a glycol-based or ester-based solvent.   The polymer compound for photoresists according to any one of claims 1 to 6, wherein the polymerization temperature in the drop polymerization is 40 to 150 ° C.   In the extraction step (B), a polymer produced by adding an organic solvent having a specific gravity of 0.95 or less and water to the polymerization solution obtained in the polymerization step (A) in which the monomer mixture is subjected to drop polymerization is extracted. The polymer compound for photoresists according to claim 1, wherein the organic component is distributed in the organic solvent layer and the metal component as an impurity is distributed in the aqueous layer. In the extraction step (B), an organic solvent having a specific gravity of 0.95 or less and a solubility parameter (SP value) of 20 MPa ^1/2 or less and water are added to the glycol-based or ester-based solvent solution of the polymer produced by the drop polymerization. The polymer compound for photoresists according to any one of claims 1 to 8, wherein the polymer extracted and distributed is distributed in an organic solvent layer and a metal component as an impurity is distributed in an aqueous layer.   Furthermore, the polymer compound for photoresists in any one of Claims 1-9 obtained through the precipitation refinement | purification process (C) which precipitates or reprecipitates the polymer produced | generated by dripping polymerization.   11. The photo according to claim 10, wherein in the precipitation purification step (C), a solution containing a polymer produced by the drop polymerization and a glycol-based or ester-based solvent is added to a solvent containing at least a hydrocarbon to precipitate or reprecipitate the polymer. High molecular compound for resist.   Furthermore, the high molecular compound for photoresists in any one of Claims 1-11 obtained through the repulping process (D) which repulps the polymer produced | generated by dripping polymerization with a solvent.   The polymeric compound for photoresists of Claim 12 which uses a hydrocarbon solvent as a repulp solvent.   Furthermore, the high molecular compound for photoresists of any one of Claims 1-13 obtained through the rinse process (E) which rinses the polymer produced | generated by dripping polymerization with a solvent.   The polymeric compound for photoresists of Claim 14 which uses a hydrocarbon solvent as a rinse solvent.   The high molecular compound for photoresists according to claim 14, wherein water is used as a rinse solvent.   The photoresist polymer compound according to claim 16, wherein the water is ultrapure water.   Furthermore, after subjecting the polymer produced | generated by dripping polymerization to precipitation refinement | purification, it is obtained through the re-dissolution process (G) which redissolves this polymer in an organic solvent, and prepares a polymer solution. The high molecular compound for photoresists as described in the item.   19. The photoresist polymer compound according to claim 18, wherein at least one solvent selected from a glycol solvent, an ester solvent, and a ketone solvent is used as the redissolving solvent.   19. The photoresist according to claim 18, which is obtained through an evaporation step (H) in which a polymer solution obtained by redissolving in an organic solvent is concentrated to remove a low boiling point solvent to prepare a polymer solution for photoresist. High molecular compound.   A polymer solution containing a polymer having a repeating unit corresponding to at least one monomer selected from the monomers (a), (b) and (c), which is provided before the step (I). The high molecular compound for photoresists according to claim 1, which is obtained through a filtration step (J) of removing insoluble matters by filtration.   A polymer solution containing a polymer having a repeating unit corresponding to at least one monomer selected from the monomers (a), (b) and (c), which is provided before the step (I). The high molecular compound for photoresists according to claim 1, which is obtained through a water washing treatment step (K) in which the metal content in the polymer solution is reduced by washing with water.   A polymer solution for photoresist containing the polymer compound for photoresist according to any one of claims 1 to 22.   A photoresist resin composition comprising at least the polymer compound for photoresist according to any one of claims 1 to 22 and a photoacid generator. A method for producing a semiconductor, comprising a step of forming a photosensitive layer using the resin composition for photoresists according to claim 24 and forming a pattern through exposure and development.