JP2009185095A - Method for producing photoresist polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a photoresist polymer for sufficiently reducing contamination by a foreign matter and efficiently and stably producing a photoresist polymer reduced in a foreign matter amount. <P>SOLUTION: The method for producing a photoresist polymer comprises: a polymer solution preparation step of preparing a polymer solution containing the photoresist polymer by polymerizing a polymerizable compound in the presence of a solvent; and a precipitation step of precipitating the photoresist polymer from the polymer solution. Each of containers used in the polymer solution preparation step and the precipitation step has a glass lining layer, which is formed of a glass lining composition containing an electroconductivity imparting substance (for example, platinum), at least on the inner surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a photoresist polymer. More specifically, the present invention relates to a method for producing a photoresist polymer that can sufficiently reduce the amount of foreign matter and can efficiently and safely obtain a photoresist polymer with a reduced amount of foreign matter. .

  In the field of microfabrication represented by the manufacture of integrated circuit elements, lithography technology capable of finer processing is required to obtain a higher degree of integration. However, in the conventional lithography process, near ultraviolet rays such as i rays are generally used as radiation, and it is said that fine processing at the subquarter micron level is extremely difficult with this near ultraviolet rays. Therefore, for example, in order to enable fine processing at a level of 0.10 μm or less, use of radiation having a shorter wavelength is being studied. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far-ultraviolet rays typified by an excimer laser, an X-ray, an electron beam, and the like. ) Or ArF excimer laser (wavelength 193 nm) has been attracting attention.

Used for photolithography such as radiation-sensitive resin composition for resist formation, resin composition for forming upper layer film and lower layer film (antireflection film, etc.) in multilayer resist, suitable for irradiation by such radiation Many resin compositions have been proposed.
The polymer contained in the resin composition used in the photolithography includes physical properties such as optical properties, chemical properties, coatability, and adhesion to the substrate or lower layer film required for resist films and antireflection films. In addition to the above properties, the polymer for photoresist is required to reduce the content of foreign substances as much as possible. In particular, in the manufacturing process of semiconductor materials that require a fine and precise shape, the inclusion of metallic foreign matter will adversely affect shape defects, etc. Reduction management is essential.

In addition, in the resin contained in the resin composition, impurities that are added or generated during the polymerization reaction, such as unreacted monomers, polymerization initiators and chain transfer agents, and coupling products thereof, remain in lithography. Volatilization may damage the exposure apparatus, or polymerization may proceed during storage as a resin or a resin composition for lithography, and a substance that causes pattern defects may be generated.
Accordingly, when the resin is produced, a purification step for removing these impurities is required, and conventionally, various methods for producing and purifying a resin including a resin purification step by reprecipitation are known ( For example, see Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 2002-62667 JP 2005-132974 A

  However, in the conventional resin production method, impurities added or generated during the polymerization reaction, such as foreign metal, unreacted monomer, polymerization initiator and chain transfer agent, and coupling products thereof, can be sufficiently reduced. However, the current situation is that further improvement is required.

  The present invention has been made in view of the above circumstances, and can provide a photoresist polymer that can sufficiently reduce the amount of foreign matter and can efficiently and safely obtain a photoresist polymer with a reduced amount of foreign matter. It is an object to provide a method for producing a polymer for use.

The present inventors have examined the use of a glass-lined container having excellent solvent resistance and the like in order to reduce metal foreign matter in the photoresist polymer. At the same time, in order to reduce impurities added or generated during the polymerization reaction, a polymerization solvent capable of allowing the polymerization reaction to proceed with high efficiency is selected in the polymer solution preparation step, and purification is performed in the precipitation step. The selection of highly effective precipitation solvents was investigated. As a result, when the electrical conductivity of the polymerization solvent used in the preparation of the polymer solution for photoresist or the poor solvent used in the purification step by precipitation is low, the volume resistivity of the glass lining material is 1 × 10 ¹³ Ωcm. Due to the high degree, it was found that electrostatic charge was generated in the container used in each step during stirring, and the container was destroyed by the static electricity, which could cause contamination of foreign objects such as metal foreign objects.
As a result of further intensive studies, as a container used for each step of the polymer solution preparation step and the precipitation step, from a glass lining composition that intentionally contains a conductivity-imparting substance that was considered an impurity in photolithography. Surprisingly, when a container having a glass lining layer to be formed is used, it is possible to sufficiently reduce the amount of metal foreign matter and to solve problems related to the generation of static electricity caused by the solvent used in each step. The headline and the present invention were completed.

The present invention is as follows.
1. A method for producing a photoresist polymer, [1] a polymer solution preparation step of preparing a polymer solution containing a photoresist polymer by polymerizing a polymerizable compound in the presence of a solvent; [2] A precipitation step of precipitating a photoresist polymer from the polymer solution, and the containers used in the polymer solution preparation step and the precipitation step each contain a conductivity-imparting substance. A method for producing a photoresist polymer, comprising a container having at least an inner surface of a glass lining layer formed from a glass lining composition.
2. 1. The conductivity-imparting substance is platinum. The manufacturing method of the polymer for photoresists of description.
3. The polymerization solvent used in the polymer solution preparation step is water, acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, tetrohydrofuran, dioxane, propylene glycol monomethyl ether, ethyl lactate, propylene glycol monomethyl ether acetate, benzene. And at least one of toluene and 1. Or 2. The manufacturing method of the polymer for photoresists of description.
4). The poor solvent used in the precipitation step is at least one of water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, pentane, hexane, heptane, cyclohexane, methylcyclohexane, benzene and toluene 1. To 3. The manufacturing method of the polymer for photoresists in any one of these.

  According to the method for producing a photoresist polymer of the present invention, a container having a glass lining layer having conductivity is used in each step of the polymer solution preparation step and the precipitation step. Can be suppressed. Moreover, since the said container is used, generation | occurrence | production of static electricity can be suppressed and the polymer for photoresists can be manufactured safely and efficiently. Furthermore, by using such a photoresist polymer with a significantly reduced amount of foreign matter, it is possible to sufficiently suppress the occurrence of defects caused by foreign matter in the manufacture of semiconductor elements, liquid crystal display elements, and the like. In addition, the sensitivity and resolution can be improved, and a desired pattern can be formed with high accuracy.

Hereinafter, the present invention will be described in detail.
The method for producing a photoresist polymer of the present invention is a method for producing a photoresist polymer, [1] containing a photoresist polymer by polymerizing a polymerizable compound in the presence of a solvent. A polymer solution preparation step for preparing a polymer solution; and [2] a precipitation step for precipitating a polymer for photoresist from the polymer solution, and used in the polymer solution preparation step and the precipitation step. Each of the containers is a container having at least an inner surface of a glass lining layer formed of a glass lining composition containing a conductivity-imparting substance.

[1] Polymer Solution Preparation Step In the polymer solution preparation step, a polymer solution containing a photoresist polymer is prepared by polymerizing a polymerizable compound in the presence of a solvent (polymerization solvent).
The polymerizable compound is usually used for photolithography of a radiation-sensitive resin composition for resist formation, a resin composition for forming an upper layer film or a lower layer film (antireflection film, etc.) in a multilayer resist. The polymeric compound (monomer) which has an ethylenically unsaturated bond used for manufacture of resin for photoresists (polymer) contained in a resin composition can be mentioned.

  Here, for example, the polymer contained in the positive-type radiation-sensitive resin composition for resist formation is at least a repeating unit having a chemical structure that is decomposed by an acid and becomes soluble in an alkali developer, more specifically, Includes a repeating unit (1) having a chemical structure in which a non-polar substituent is dissociated by an acid and a polar group soluble in an alkali developer is expressed, and a polar group for enhancing adhesion to a substrate such as a semiconductor substrate. It has a repeating unit (2) having an essential component, and includes a repeating unit (3) having a nonpolar substituent for adjusting the solubility in a solvent or an alkaline developer as necessary. Yes.

  The repeating unit (1) that is decomposed by an acid and becomes alkali-soluble means a chemical structure generally used as a conventional resist, and a monomer having a chemical structure that is decomposed by an acid and becomes alkali-soluble. After polymerizing or polymerizing a monomer having an alkali-soluble chemical structure, the substituent having an alkali-soluble group (alkali-soluble group) in the alkali-soluble chemical structure is dissociated by an acid without being dissolved in the alkali. It can be obtained by protecting with a group (acid-dissociable protecting group).

Examples of the monomer having a chemical structure that becomes alkali-soluble when decomposed by an acid include compounds in which an acid-dissociable protecting group is bonded to a polymerizable compound containing an alkali-soluble substituent. And compounds having a phenolic hydroxyl group, a carboxyl group or a hydroxyfluoroalkyl group protected with an acid dissociable protecting group. Specifically, for example, hydroxystyrenes such as p-hydroxystyrene, m-hydroxystyrene, p-hydroxy-α-methylstyrene; acrylic acid, methacrylic acid, maleic acid, fumaric acid, α-trifluoromethylacrylic acid , 5-norbornene-2-carboxylic acid, 2-trifluoromethyl-5-norbornene-2-carboxylic acid, carboxytetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] carboxylic acids having an ethylenic double bond such as dodecyl methacrylate; p- (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) styrene, 2- ( 4- (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) cyclohexyl) -1,1,1,3,3,3-hexafluoropropyl acrylate, 2- (4 -(2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) cyclohexyl) -1,1,1,3,3,3-hexafluoropropyltrifluoromethyl acrylate, 5- Polymerizable compounds having a hydroxyfluoroalkyl group such as (2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl) methyl-2-norbornene That.

Examples of the acid dissociable protecting group include a tert-butyl group, a tert-amyl group, a 1-methyl-1-cyclopentyl group, a 1-ethyl-1-cyclopentyl group, and a 1-methyl-1-cyclohexyl group. 1-ethyl-1-cyclohexyl group, 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 2-propyl-2-adamantyl group, 2- (1-adamantyl) -2-propyl group, 8-methyl-8-tricyclo [5.2.1.0 ^2,6 ] decanyl group, 8-ethyl-8-tricyclo [5.2.1.0 ^2,6 ] decanyl group, 8-methyl-8- Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecanyl group, 8-ethyl-8-tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] saturated hydrocarbon group such as dodecanyl group; 1-methoxyethyl group, 2-ethoxyethyl group, 1-iso-propoxyethyl group, 1-n-butoxyethyl group, 1-tert-butoxyethyl group, 1-cyclopentyloxyethyl group, 1-cyclohexyloxyethyl group, 1-tricyclo [5.2.1.0 ^2,6 ] decanyloxyethyl group, methoxymethyl group, ethoxymethyl group, iso-propoxymethyl group, n Oxygenated carbon such as -butoxymethyl group, tert-butoxymethyl group, cyclopentyloxymethyl group, cyclohexyloxymethyl group, tricyclo [5.2.1.0 ^2,6 ] decanyloxymethyl group, tert-butoxycarbonyl group A hydrogen group etc. are mentioned.

  After polymerizing a monomer having an alkali-soluble chemical structure and then protecting the alkali-soluble group in the alkali-soluble chemical structure with an acid-dissociable protecting group, the compound having the alkali-soluble group is directly polymerized. Then, an acid-dissociable protecting group can be introduced by reacting with a compound that gives a substituent that does not dissolve in an alkali such as vinyl ether or halogenated alkyl ether under an acid catalyst. Examples of the acid catalyst used in the reaction include p-toluenesulfonic acid, trifluoroacetic acid, and strongly acidic ion exchange resin.

  Examples of the monomer that gives the repeating unit (2) having a polar group for improving adhesion to the substrate include compounds having a phenolic hydroxyl group, a carboxyl group, or a hydroxyfluoroalkyl group as the polar group. Specifically, for example, as the polymerizable compound containing an alkali-soluble group, hydroxystyrenes described above, carboxylic acids having an ethylenic double bond, polymerizable compounds having a hydroxyfluoroalkyl group, and these In addition to the monomer further substituted with a polar group, a monomer having a polar group bonded to an alicyclic structure such as a norbornene ring or a tetracyclododecene ring can be used.

The polar group introduced into the repeating unit (2) as a substituent is particularly preferably one containing a lactone structure, such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, 1,3-cyclohexanecarbolactone. , 2,6-norbornanecarbolactone, 4-oxatricyclo [5.2.1.0 ^2,6 ] decan-3-one, and a substituent containing a lactone structure such as mevalonic acid δ-lactone.
Examples of polar groups other than the lactone structure include hydroxyalkyl groups such as a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, and a 3-hydroxy-1-adamantyl group.

Furthermore, as a monomer which gives the repeating unit (3) having a nonpolar substituent for adjusting the solubility in a resist solvent or an alkali developer, which is contained as necessary, styrene, α-methyl Aromatic compounds having an ethylenic double bond such as styrene, p-methylstyrene, and indene; acrylic acid, methacrylic acid, trifluoromethyl acrylic acid, norbornene carboxylic acid, 2-trifluoromethyl norbornene carboxylic acid, carboxytetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] ester compound in which acid-stable nonpolar group is substituted for carboxylic acid having ethylenic double bond such as dodecyl methacrylate; alicyclic carbonization having ethylenic double bond such as norbornene and tetracyclododecene A hydrogen compound etc. are mentioned.
Examples of acid-stable nonpolar substituents that are ester-substituted for the carboxylic acid include methyl, ethyl, cyclopentyl, cyclohexyl, isobornyl, and tricyclo [5.2.1.0 ^2,6 ] decanyl. Group, 2-adamantyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl group and the like.

These monomers may be used individually by 1 type in each of repeating unit (1), (2), and (3), and may be used in combination of 2 or more type.
The composition ratio of each repeating unit in the polymer contained in the positive-type radiation-sensitive resin composition for resist formation can be selected within a range that does not impair the basic performance as a resist. That is, in general, the repeating unit (1) is preferably 10 to 70 mol%, more preferably 10 to 60 mol%. The composition ratio of the repeating unit (2) is preferably 30 to 90 mol%, more preferably 40 to 90 mol%, but for the monomer unit having the same polar group, 70 mol% The following is preferable. Furthermore, the composition ratio of the repeating unit (3) is preferably 50 mol% or less, more preferably 40 mol% or less.

  On the other hand, the polymer contained in the resin composition for forming the upper layer film and the lower layer film (antireflection film, etc.) in the multilayer resist is the polymer contained in the positive-type radiation-sensitive resin composition for resist formation described above. A polymer having a chemical structure obtained by removing the repeating unit (1) which is decomposed with an acid and becomes alkali-soluble by being decomposed with an acid is used. The composition ratio of each repeating unit in a polymer is not specifically limited, It adjusts suitably according to the intended purpose of a coating film. Generally, the composition ratio of the repeating unit (2) is selected from the range of 10 to 100 mol%, and the composition ratio of the repeating unit (3) is selected from the range of 0 to 90 mol%.

  Furthermore, when the upper layer film or the lower layer film in the multilayer resist is used as an antireflection film, the polymer needs to include a crosslinking point and a chemical structure that absorbs radiation irradiated in photolithography, Examples of the crosslinking point include reactive substituents that can be crosslinked by an ester bond, a urethane bond, or the like, such as a hydroxyl group, an amino group, a carboxyl group, or an epoxy group. Examples of the monomer containing a reactive substituent serving as a crosslinking point include hydroxystyrenes such as p-hydroxystyrene and m-hydroxystyrene, and the above-described polymerizable compounds such as the hydroxyl group, amino group, and carboxyl. A monomer substituted with a reactive substituent such as a group or an epoxy group can be appropriately used.

  The chemical structure that absorbs radiation varies depending on the wavelength of the radiation used. For example, for ArF excimer laser light, a chemical structure containing a benzene ring and its analogs is preferably used. Examples of the monomer having such a chemical structure include styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-hydroxystyrene, m-hydroxystyrene, and derivatives thereof; substituted or unsubstituted phenyl (meta And aromatic-containing esters having an ethylenic double bond such as acrylate, substituted or unsubstituted naphthalene (meth) acrylate, substituted or unsubstituted anthracenemethyl (meth) acrylate, and the like. The monomer having a chemical structure that absorbs radiation may be introduced as either the repeating unit (2) or (3) depending on the presence or absence of a polar group, but the monomer having a chemical structure that absorbs radiation. Is preferably selected from the range of 10 to 100 mol%. In the present specification, “(meth) acrylate” means acrylate and methacrylate.

Moreover, the polymerization method of the said polymeric compound is not specifically limited, Well-known methods, such as solution polymerization, can be used.
The polymer solution containing the photoresist polymer uses, for example, a polymerization initiator, and further uses a chain transfer agent as necessary, and the above-described polymerizable compound (that is, polymerizable unsaturated monomer). Can be obtained by polymerizing in a suitable solvent.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), dimethyl 2,2′-azobisisobutyrate, 1,1′- Azo compounds such as azobis (cyclohexane-1-carbonitrile), 4,4′-azobis (4-cyanovaleric acid), decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, bis (3,5,5-trimethyl) Examples include radical polymerization initiators such as organic peroxides such as hexanoyl peroxide, succinic acid peroxide, and tert-butylperoxy-2-ethylhexanoate. These polymerization initiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the chain transfer agent include thiol compounds such as dodecyl mercaptan, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid, and 4,4-bis (trifluoromethyl) -4-hydroxy-1-mercaptobutane. be able to. These chain transfer agents may be used individually by 1 type, and may be used in combination of 2 or more type.

The amount of the polymerization initiator and chain transfer agent used is the production conditions such as the raw material monomer (polymerizable compound) and polymerization initiator used in the polymerization reaction, the type of chain transfer agent, the polymerization temperature, the polymerization solvent, the polymerization method, and the purification conditions Can be adjusted as appropriate.
Generally, when the weight average molecular weight of a polymer is too high, the solubility in a solvent or an alkali developer used for forming a coating film tends to be low. On the other hand, when the weight average molecular weight is too low, the coating film performance tends to deteriorate. Therefore, the polystyrene-reduced weight average molecular weight (hereinafter also referred to as “Mw”) by gel permeation chromatography (GPC) is preferably adjusted to be in the range of 2000 to 40000, more preferably 3000 to 30000.

  The polymerization solvent used in the polymerization reaction is not particularly limited. For example, water, acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, tetrohydrofuran, dioxane, propylene glycol monomethyl ether, ethyl lactate, propylene glycol monomethyl It is preferable to use at least one of ether acetate, benzene and toluene. When these polymerization solvents are used, it is possible to obtain a photoresist polymer with a high yield and less impurities. Furthermore, the molecular weight distribution of the obtained photoresist polymer can be narrowed, and the physical properties such as optical properties, chemical properties, coatability, and adhesion to the substrate or lower layer film required for resist films and antireflection films are reduced. Properties can be improved.

  Although the usage-amount of the said polymerization solvent is not specifically limited, Usually, it is 0.5-20 mass parts with respect to 1 mass part of monomers, Preferably it is 1-10 mass parts. If the amount of the solvent used is too small, the monomer may precipitate or become too viscous to keep the polymerization system uniform. On the other hand, when the amount of the solvent used is too large, the conversion rate of the raw material monomers may be insufficient, or the molecular weight of the resulting polymer may not be increased to a desired value.

Moreover, the reaction conditions in the said polymerization are not specifically limited, However, Reaction temperature is 40-120 degreeC normally, Preferably it is 50-100 degreeC. The reaction time is usually 1 to 48 hours, preferably 1 to 24 hours.
The concentration (solid content concentration) of the polymer solution obtained in this polymer solution preparation step is preferably 1 to 80% by mass, more preferably 5 to 50% by mass, and still more preferably 10 to 50% by mass. is there.

  In this polymer solution preparation step, a container provided with at least an inner surface of a glass lining layer formed from a glass lining composition containing a conductivity imparting substance is used as a polymerization reaction container. In the present invention, this conductive container is used in the polymer preparation step, so that static electricity generated from the above preferred polymerization solvent during the polymerization stirring is alleviated, and problems such as breakage of the glass lining layer are suppressed. A polymer solution can be prepared safely and efficiently.

The volume resistivity of the glass lining layer is preferably 1 × 10 ¹⁰ Ωcm or less, more preferably 1 × 10 ² to 1 × 10 ⁹ Ωcm, and still more preferably 1 × 10 ⁴ to 1 × 10 ⁸ Ωcm. is there. When the volume resistivity is 1 × 10 ¹⁰ Ωcm or less, the generation of a charged potential in the glass lining layer can be suppressed to 1 kV or less, and the generation of static electricity can be sufficiently suppressed.

The glass lining composition for forming the glass lining layer usually contains a glass frit and a conductivity imparting substance.
The composition of the glass frit is not particularly limited, and examples thereof include known compositions that can provide excellent corrosion resistance (chemical durability) and thermal stability. Specifically, for example, a glass frit having a composition comprising the following (A) to (E) can be used.
(A) SiO ₂ + TiO ₂ + ZrO ₂ : 46 to 67% by mass (40 to 75% by mol) [However, SiO ₂ : 46 to 67% by mass (40 to 75% by mol), TiO ₂ : 0 to 18% by mass ( 0-20 _mol%), ZrO 2: is a 0-12 wt% (0-12 mole%). The mass percentages of the component (A) is a SiO ₂ equivalent amount. ]
_(B) R 2 O: 8~22 wt% (7-22 mole%) _[where, Na 2 O: _8~22 wt% (7-22 _mole%), K 2 O: _0~16 wt% (0 ˜15 mol%), Li ₂ O: 0 to 10 mass% (0 to 15 mol%). The mass percentages of the component (B) is a terms of Na ₂ O weight. ]
(C) RO: 0.9-7 mass% (1-7 mol%) [However, CaO: 0.9-7 mass% (1-7 mol%), BaO: 0-6 mass% (0-6) MolO), ZnO: 0-6 mass% (0-6 mol%), MgO: 0-5 mass% (0-6 mol%), SnO: 0-5 mass% (0-6 mol%), SrO : 0 to 5 mass% (0 to 6 mol%). In addition, the mass% display about a component (C) is a CaO conversion amount. ]
(D) B ₂ O ₃ + Al ₂ O ₃ : 0 to 22% by mass (0 to 20% by mol) [However, B ₂ O ₃ : 0 to 22% by mass (0 to 20% by mol), Al ₂ O ₃ : It is 0-6 mass% (0-10 mol%). The mass percentages of the component (D) _is a terms _of B 2 _{O 3} amount. ]
(E) CoO + NiO + MnO ₂ : 0 to 5% by mass (0 to 4% by mol) [However, CoO: 0 to 5% by mass (0 to 4% by mol), NiO: 0 to 5% by mass (0 to 4% by mol) , MnO ₂ : 0 to 5% by mass (0 to 4% by mol). In addition, the mass% display about a component (E) is a CoO conversion amount. ]

Moreover, it is preferable that the said electroconductivity imparting substance is platinum strong against an acid or an alkali. Moreover, it is preferable that the shape of this platinum is a fibrous form. In the case where the shape of platinum is fibrous, the conductivity is higher than in the case of other shapes, and the desired conductivity can be obtained with a smaller amount of addition, which is preferable.
The diameter of fibrous platinum (hereinafter also referred to as “platinum fiber”) is preferably 0.01 μm or more and less than 0.5 μm. When the diameter is less than 0.01 μm, it is difficult to process the platinum fiber itself, and the manufacturing cost is greatly increased. On the other hand, in the case of 0.5 μm or more, there is a possibility that the glass lining layer is not uniformly dispersed.
The length of the platinum fiber is preferably 0.5 μm or more and less than 1500 μm. When this length is less than 0.5 μm, it is difficult to process the platinum fiber itself. On the other hand, when the thickness is 1500 μm or more, the strength of the glass lining layer may be lowered.

  The added amount of platinum fiber in the glass lining composition is preferably 0.001 to 0.05 parts by mass, more preferably 0.01 to 0.05 parts by mass with respect to 100 parts by mass of the frit. is there. When this addition amount is less than 0.001 part by mass, a glass lining layer having sufficient conductivity may not be obtained. On the other hand, when it exceeds 0.05 mass part, there exists a possibility that the problem of metal content mixing to a product may arise.

  Moreover, the container provided with the said glass lining layer is a well-known glass lining composition containing the said electroconductivity imparting substance on the at least inner surface of a well-known container base material (for example, a low carbon steel plate, a stainless steel plate, etc.). It can be obtained by glazing and baking by a method.

[2] Precipitation step In the precipitation step of the present invention, impurities (especially, low molecular components such as residual monomers, dimers, trimers, oligomers, etc.) are removed from the polymer solution by a precipitation operation to produce a copolymer (photo The resist polymer is purified. The analysis of the low molecular component can be performed by high performance liquid chromatography (HPLC).
The precipitation operation is not particularly limited, and can be performed according to a conventional method. Specifically, for example, it can be carried out by dropping the polymer solution whose concentration is adjusted as necessary in a poor solvent (precipitation solvent). Moreover, the said precipitation operation may be repeated twice or more using a good solvent as needed, and a polymer may be refine | purified.

  The poor solvent is not particularly limited as long as it precipitates a predetermined polymer. For example, water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, pentane, hexane, heptane, cyclohexane, methylcyclohexane It is preferable to use at least one of benzene and toluene. When precipitation purification is performed using these poor solvents, impurities remaining in the polymer solution can be efficiently removed, and the yield of the resulting slurry of the photoresist polymer slurry can be improved. .

  Moreover, the usage-amount of the said poor solvent is not specifically limited, It adjusts suitably with the kind of poor solvent, the kind of solvent in a polymer solution, and its content. Specifically, for example, the mass conversion is preferably 0.5 to 50 times, more preferably 1 to 30 times, and still more preferably 2 to 2 times the total amount of the polymer solution to be contacted with the poor solvent. 20 times.

  Examples of the good solvent include ketones such as acetone, methyl ethyl ketone, methyl amyl ketone, and cyclohexanone; ethers such as tetrahydrofuran, dioxane, glyme, and propylene glycol monomethyl ether; esters such as ethyl acetate and ethyl lactate; propylene glycol methyl Examples include ether esters such as ether acetate, and lactones such as γ-butyrolactone. These good solvents may be used alone or in combination of two or more. The good solvent may be the same as or different from the polymerization solvent used in the polymer solution preparation step.

  Moreover, it is preferable that the temperature of the slurry liquid containing the polymer for photoresists obtained by this precipitation process is 10-35 degreeC, More preferably, it is 15-35 degreeC, More preferably, it is 20-35 degreeC. In addition, the temperature of this slurry liquid can be controlled by the temperature control apparatus with which the refiner | purifier was equipped, the temperature of the poor solvent to be used, etc.

In the precipitation operation, a container having at least an inner surface of a glass lining layer formed from a glass lining composition containing a conductivity-imparting substance is used. The above description can be applied as it is to a container having a glass lining layer on at least the inner surface. Moreover, the container provided with the glass lining layer used in a precipitation process and the said polymer solution preparation process may be the same, and may differ.
In the present invention, this conductive container is used in the precipitation step, so that static electricity generated from the preferred precipitation solvent is alleviated by stirring during slurry dispersion, and problems such as breakage of the glass lining layer are suppressed. The Furthermore, a photoresist polymer can be produced safely and efficiently.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

(1) Example 1
<Polymer solution preparation process>
A 200L-capacity polymerization reaction vessel [glass lining composition to which a conductivity-imparting substance is added [glass frit composition; equipped with at least a stirrer, a thermometer, a reflux cooling device, a monomer solution dropping nozzle, and an initiator solution dropping nozzle. _{SiO 2, TiO 2, ZrO 2} , Na 2 O, K 2 O, Li 2 O, CaO, BaO, ZnO, MgO, SnO, SrO, B 2 O 3, Al 2 O 3, CoO, NiO, MnO 2, Conductivity-imparting substance: platinum fiber (diameter 0.1 μm, length 200 μm), added amount of platinum fiber; 0.03 parts by mass with respect to 100 parts by mass of glass frit], a glass lining layer (volume resistivity; the polymerization reaction vessel] provided to 1 × 10 ⁸ Ωcm or less) the inner surface, sufficiently nitrogen location put methylethylketone (MEK) 32 kg as a polymerization solvent After the temperature was raised to 80 ° C. while stirring at 100 rpm. Thereafter, a MEK solution of 15 kg of 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM) and 20 kg of 2-methyl-2-adamantyl methacrylate (MAdMA), a MEK solution of 0.5 kg of azobisisobutyronitrile, Were added dropwise over 3 hours. After completion of the dropwise addition, the mixture was further aged for 3 hours, and then cooled to room temperature to prepare a polymer solution. As a result of measurement using high performance liquid chromatography, the monomer conversion was 91%, and the amount of residual monomer relative to 100% by mass of the polymer was 9% by mass. Moreover, as a result of measuring a weight average molecular weight (Mw) and a number average molecular weight (Mn) about the obtained polymer, molecular weight distribution (dispersion degree Mw / Mn) was 1.71.

<Precipitation process>
Thereafter, 20 kg of the obtained polymer solution (solid content concentration: about 25% by mass) is placed in a container having a conductive glass lining layer with a volume of 200 L [glass lining composition to which a conductivity-imparting substance is added (glass frit composition; _{SiO 2, TiO 2, ZrO 2} , Na 2 O, K 2 O, Li 2 O, CaO, BaO, ZnO, MgO, SnO, SrO, B 2 O 3, Al 2 O 3, CoO, NiO, MnO 2, Conductivity-imparting substance; glass fiber lining layer (volume resistivity; formed from platinum fiber (diameter 0.1 μm, length 200 μm), platinum fiber addition amount; 0.03 part by mass with respect to 100 parts by mass of glass frit) among the polymerization reactor] provided on the inner surface of the 1 × 10 ⁸ Ωcm or less), while stirring at 150rpm methanol solution of 100 kg, a drop of 12.5 g / min It was added dropwise at a rate to give a white slurry solution by practice of the precipitate.
Then, using a pressure filter with a Teflon (registered trademark) filter cloth (aeration rate: 3.0 cm ³ / cm ² · sec, filtration area: 1 m ² ) on the bottom of the container, nitrogen was added at 0.2 MPa. A white solid (a polymer for photoresist) was obtained by filtering the slurry under pressure. In addition, as a result of measuring using the high performance liquid chromatography about the obtained polymer for photoresists, the amount of residual monomers with respect to 100 mass% of polymers was 0.08 mass%. The molecular weight distribution was 1.47.
Next, this white solid was dissolved in 50 kg of propylene glycol monomethyl ether acetate (PGMEA) for 1 hour to obtain a photoresist polymer solution. The obtained photoresist polymer solution had no undissolved content and was a clear solution.

The Mw and Mn are values measured as follows.
Using GPC columns (trade name “G2000HXL”, product name “G3000HXL”, product name “G4000HXL” 1) made by Tosoh Corporation, flow rate: 1.0 ml / min, elution solvent: tetrahydrofuran, Column temperature: Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C.

(2) Comparative Example 1
In the polymer solution preparation step and the precipitation step in Example 1, Example 1 was used except that a container having at least an inner surface of a glass lining layer made of a glass lining composition to which no conductivity-imparting substance was added was used. Similarly, a photoresist polymer solution was obtained. The photoresist polymer obtained in the polymer solution preparation step in Comparative Example 1 has a molecular weight distribution of 1.74, a monomer conversion of 91%, and a residual monomer with respect to 100% by mass of the polymer. The amount was 9% by mass. Moreover, in the polymer for photoresists obtained at the precipitation process, molecular weight distribution was 1.47, and the amount of residual monomers with respect to 100 mass% of polymers was 0.08 mass%.

(3) Performance evaluation
<Amount of foreign metal>
In each photoresist polymer solution obtained in Example 1 and Comparative Example 1, the amount of metal foreign matter was measured by the following method.
1 g of the polymer solution for photoresist was put in a quartz crucible, and propylene glycol monomethyl ether acetate (PEGMEA) was completely evaporated, followed by ashing at 550 ° C. Subsequently, it melt | dissolved in aqua regia and measured the amount of metal foreign materials with the dielectric coupling plasma mass spectrometer (brand name "ELAN DRC Plus") made from PerkinElmer. The types of metals evaluated are Na, Si, Ti, K, Li, Ba, Zn, Mg, Sn, Sr, B, Al, Co, Ni, Zr, Ca, Mn, and Pt.

<Damage in container>
The damage state of the container provided with the glass lining layer used in the polymer solution preparation step and the precipitation step in Example 1 and Comparative Example 1 was visually confirmed.

(4) Evaluation results The amount of metal foreign matter in the photoresist polymer solution obtained in Example 1 was less than the lower limit of detection amount of the measuring instrument (ND = less than 0.5 ppb) for all measured metal species. . Moreover, in each container provided with the glass lining layer used in the polymer solution preparation step and the precipitation step in Example 1, no damage was confirmed.
The amount of metal foreign matter in the photoresist polymer solution obtained in Comparative Example 1 was less than the lower limit of detection amount of the measuring instrument (ND = less than 0.5 ppb) for all measured metal species. In both the container used in the preparation process and the container used in the precipitation process, damage due to static electricity was confirmed.

Claims (4)

A method for producing a polymer for photoresist, comprising:
[1] A polymer solution preparation step of preparing a polymer solution containing a photoresist polymer by polymerizing a polymerizable compound in the presence of a solvent;
[2] a precipitation step of precipitating a polymer for photoresist from the polymer solution,
The containers used in the polymer solution preparation step and the precipitation step are containers each having at least an inner surface of a glass lining layer formed from a glass lining composition containing a conductivity-imparting substance. A method for producing a photoresist polymer.   The method for producing a photoresist polymer according to claim 1, wherein the conductivity imparting substance is platinum.   The polymerization solvent used in the polymer solution preparation step is water, acetone, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, tetrohydrofuran, dioxane, propylene glycol monomethyl ether, ethyl lactate, propylene glycol monomethyl ether acetate, benzene. The method for producing a photoresist polymer according to claim 1, which is at least one of toluene and toluene.   The poor solvent used in the precipitation step is at least one of water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, pentane, hexane, heptane, cyclohexane, methylcyclohexane, benzene and toluene. Item 4. A method for producing a photoresist polymer according to any one of Items 1 to 3.