JP2009249400A - Method for producing polymer for photoresist - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-productivity method, by which contamination by impurities (a foreign metal and a metal constituent in particular) can be sufficiently reduced in a production process, for producing a polymer with a maximally reduced impurity content for a photoresist. <P>SOLUTION: The method for producing a polymer for a photoresist includes a process for feeding a liquid material by a plurality of nonmetal lining pipes. In the joint part between the nonmetal lining pipes, an earth material is inserted so as to be brought into contact with the liquid material to be supplied, and the liquid material is supplied while grounding the earth material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a photoresist polymer used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photolithography processes.

  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, it is said that it is extremely difficult to perform fine processing at a sub-quarter micron level of 0.10 μm or less in a lithography process using near ultraviolet rays such as i-line as a light source.

  Therefore, in order to enable fine processing at the sub-quarter micron level, it has been studied to use radiation having a shorter wavelength as a light source. Examples of such short-wavelength radiation include an emission line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, X-rays, and electron beams. Among these radiations, KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm) are attracting attention.

  By the way, in the field of fine processing as described above, various photoresists such as a radiation-sensitive polymer for forming a resist, a polymer for forming an upper layer film of a multilayer resist, and a polymer for forming a lower layer film (antireflection film, etc.). Polymers for use are used.

  These photoresist polymers have optical properties, chemical properties, applicability, product intrinsic properties such as adhesion to substrates and lower layers, as well as foreign materials such as metallic foreign materials, metal components, etc. It is required to avoid the contamination of impurities as much as possible. In particular, for photoresist polymers for semiconductor materials that require fine and precise processing, the incorporation of foreign matter immediately leads to defects such as shape defects, and the incorporation of metal components also increases defects or quality over time. In order to cause problems such as a decrease, it is required to reduce the content of impurities as much as possible.

  Therefore, in the production of a photoresist polymer, a method using a non-metallic lining pipe is known instead of the metallic pipe used for feeding raw materials, intermediates, products, etc. There is no specific prior art document on the method.) Non-metallic lining pipes are pipes in which non-metallic materials such as glass and fluororesin (registered trademark: Teflon) are lined on the inner surface of metal pipes, and contain impurities (especially metallic impurities) of photoresist polymers. It can be expected to reduce the amount.

  Also known is a method for reducing the impurity content of a photoresist polymer by removing foreign matters in the photoresist polymer using a filter or ion exchange membrane having a small pore size (for example, patents). Reference 1-5).

Japanese Patent Laid-Open No. 2002-62667 JP 2005-132974 A JP 2005-3000737 A JP 2003-330202 A JP 2004-195427 A

  However, it is difficult to say that the above-mentioned method can reduce the content of impurities (particularly metal foreign matters and metal components) to a sufficiently satisfactory level, and in terms of obtaining a photoresist polymer having a low impurity content. It still left issues.

In addition, the method using the non-metallic lining pipe has no conductivity in the non-metallic material lining pipe (glass lining: volume resistivity about 1 × 10 ¹³ Ωcm, fluororesin lining: volume resistivity about 1 × 10 ¹⁸ Ωcm), The problem was that static electricity was likely to accumulate.

  In other words, even if liquid is fed at a relatively low speed (about 0.8 to 1.0 m / s), static electricity is accumulated in the pipe and the lining may be destroyed by static electricity. There has been a problem that foreign substances and metal components are mixed as impurities into the photoresist polymer. On the other hand, in order to avoid the generation of static electricity, there has been a problem that the productivity of the product is remarkably lowered when the liquid feeding speed is lowered.

  Furthermore, when the method of excluding foreign matters like the methods described in Patent Documents 1 to 5 is employed, the filter is likely to be clogged, and the time and labor required for the filtration process are enormous. Therefore, there is a problem that the productivity of the product is extremely low. Since the photoresist polymer is forced to be produced in a small amount and a wide variety, it can be said that a decrease in productivity is a serious problem.

  The present invention has been made in view of such problems of the prior art, has high productivity, can sufficiently suppress the mixing of impurities (particularly metal foreign matters and metal components) in the manufacturing process, The present invention provides a method for producing a photoresist polymer capable of obtaining a photoresist polymer with a content reduced as much as possible.

  As a result of intensive studies to solve the problems of the prior art as described above, even when non-metallic lining piping is used, a grounding material is inserted into a connecting portion between pipings, and the grounding material is used. By grounding and discharging static electricity, it was found that even when liquid is fed at a relatively high speed, static damage of the lining does not occur, and contamination of impurities (especially metal foreign matters and metal components) can be avoided. It came to be completed. Specifically, the present invention provides the following method for producing a photoresist polymer.

[1] A step of feeding a liquid material through a plurality of non-metallic lining pipes, and inserting a grounding material into a connection portion between the non-metallic lining pipes so as to contact the liquid material to be fed, A method for producing a photoresist polymer, wherein the liquid material is fed while a grounding material is grounded.

[2] The manufacturing method according to [1], wherein the ground material is made of at least one metal selected from the group consisting of stainless steel, tantalum, titanium, zirconium, and a nickel-base superalloy.

[3] The production method according to [1] or [2], wherein the liquid material is one of a photoresist polymer solution and a photoresist polymer slurry.

[4] The production method according to any one of [1] to [3], wherein the liquid material includes at least one solvent selected from a saturated hydrocarbon solvent, a ketone solvent, and an acetate solvent. .

[5] The saturated hydrocarbon solvent is pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, and the ketone solvent is methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, 2-heptanone, cyclohexanone, The production method according to [4], wherein the acetate solvent is ethylene glycol monomethyl ether acetate or propylene glycol monomethyl ether acetate.

[6] An annular seal provided with a plurality of non-metallic lining pipes, wherein a pipe-connecting packing is sandwiched between connecting parts of the non-metallic lining pipes, and the pipe-connecting packing can come into contact with the flange surface of the pipe A piping structure comprising a material and a grounding material that is sandwiched between the sealing materials and disposed so that at least a part thereof is exposed in the ring of the sealing materials.

  The production method of the present invention is highly productive, and can sufficiently prevent contamination of impurities (particularly metal foreign matters and metal components) during the production process, thereby obtaining a photoresist polymer in which the impurity content is reduced as much as possible. be able to.

  Hereinafter, the best mode for carrying out the present invention will be described, but the present invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are also within the scope of the present invention based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

  In this specification, “(meth) acrylate” means both acrylate and methacrylate.

[1] Characteristic configuration of the present invention:
As shown in FIG. 1, the method for producing a photoresist polymer of the present invention includes a step of feeding a liquid material through a plurality of non-metallic lining pipes 2A and 2B, and the connection between the non-metallic lining pipes 2A and 2B. In this manufacturing method, the grounding material 4A is inserted into the section so as to be in contact with the liquid material to be fed, and the liquid material is fed in a state where the grounding material 4A is grounded.

  By lining the metal pipe with a non-metallic material, it is possible to effectively prevent contamination of metal foreign substances and elution of metal components.

  Further, even when non-metallic lining piping that is not conductive and easily accumulates static electricity can be used, the static electricity can be released from the grounding material. Therefore, electrostatic breakdown of the lining portion due to accumulation of static electricity does not occur, and it is possible to sufficiently suppress the occurrence of metal foreign matters and metal components derived from metal piping as impurities in the photoresist polymer during the manufacturing process. This makes it possible to obtain a photoresist polymer with the impurity content reduced as much as possible. The photoresist polymer in which the amount of impurities is greatly reduced can sufficiently suppress defects such as defects caused by impurities when manufacturing a semiconductor element, a liquid crystal display element or the like. Therefore, it is useful in that the sensitivity and resolution of the photoresist material can be improved and a desired pattern can be formed with high accuracy.

  Furthermore, even if the liquid is fed at a relatively high speed (for example, about 1 to 10 m / s), in addition to the electrostatic breakdown of the lining portion not occurring, it is possible to avoid the introduction of foreign matters. Even when the filtration step is unnecessary or filtration is performed, the filtration time and labor can be reduced. Therefore, the productivity of the product can be dramatically improved.

[1-1] Non-metallic lining piping:
“Non-metallic lining pipe” means a pipe in which the inner surface of the metal pipe 6 is covered with a lining 8 made of a non-metallic material such as glass or resin, like the non-metal lining pipes 2A and 2B shown in FIG. . Examples of the non-metallic material used as the lining material include glass and fluororesin (registered trademark: Teflon). In this specification, the term “lining” includes coating (less than 1 mm of film thickness) in addition to lining (film thickness of 1 mm or more).

[1-2] Liquid material:
The manufacturing method of the present invention includes a step of feeding a liquid material through a plurality of non-metallic lining pipes. “Liquid” includes liquids, solutions, slurries and the like. Specific examples include a monomer used as a raw material for a polymer, a solvent used for reaction and reprecipitation, a solution of a polymerization initiator, a polymerization solution after reaction, a slurry after reprecipitation, a polymer solution of a product, and the like. Can do. Accordingly, pipes such as raw material / solvent charging pipes, intermediate and product liquid feeding pipes, product take-out pipes, filtration circulation pipes and the like can be applied to the production method of the present invention.

  Since the production method of the present invention can achieve high productivity (high yield), the liquid substance is acetone, methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, 2-heptanone, tetrahydrofuran, dioxane, glyme, Ethylene glycol monomethyl ether, ethyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, cyclohexanone, γ-butyrolactone, ethyl lactate, methanol, ethanol, 1-propanol, 2-propanol, pentane, hexane, heptane, octane, cyclohexane It is preferable that it contains at least one solvent selected from the group consisting of methylcyclohexane, benzene, toluene and xylene.

  Among these, it is more preferable that the liquid material contains at least one solvent selected from saturated hydrocarbon solvents, ketone solvents, and acetate solvents. This is because these solvents are likely to generate static electricity by stirring and transporting, and thus the effect of the application of the present invention is great.

  Examples of the “saturated hydrocarbon solvent” include chain saturated hydrocarbons such as pentane, hexane, heptane and octane; cyclic saturated hydrocarbons such as cyclohexane and methylcyclohexane; Examples of the “ketone solvent” include chain ketones such as methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, and 2-heptanone; cyclic ketones such as cyclohexanone; Examples of the “acetate solvent” include glycol acetates such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate.

  In the production method of the present invention, the liquid material is preferably one of a photoresist polymer solution and a photoresist polymer slurry. That is, it is preferable to insert a grounding material into the connection portion of the pipe for feeding these. The polymer solution and the polymer slurry often contain a saturated hydrocarbon solvent, a ketone solvent, an acetate solvent, and the like, and static electricity is likely to be generated by stirring or transferring. Therefore, the effect of applying the present invention is great.

[1-3] Earth material:
In the manufacturing method of the present invention, an earth material is used. As the “earth material”, a material made of a conductive material such as metal can be used. Especially, it is preferable that it consists of at least 1 sort (s) of metal selected from the group of stainless steel, a tantalum, titanium, a zirconium, and a nickel base superalloy. The earthing material made of these materials can effectively prevent the elution of metal components into the photoresist polymer and the like as well as the effect of removing static electricity.

  “Stainless steel” is preferably made of SUS316, SUS316L, SUS304 or SUS420 because metal elution is reduced at a higher level, and those whose surfaces are subjected to physical polishing treatment or electrolytic polishing treatment are further preferred. preferable. As the “nickel-based superalloy”, Hastelloy (trade name) or the like can be preferably used.

  The shape of the ground material is not particularly limited as long as it can be inserted from the connecting portion between the pipes. For example, as shown in FIGS. 2A and 2B, an annular grounding material 4A in which a center hole 16 is formed can be suitably used.

  From the viewpoint of bringing the annular ground material into contact with the liquid material inside the pipe, the inner diameter of the center hole is configured to be equal to or less than the inner diameter of the pipe, and the inner circumference of the ground material protrudes from the inner peripheral surface of the non-metallic lining pipe. It is preferable to configure so as to. For example, if a non-metallic lining pipe having an inner diameter of 13 mmφ is used, the annular grounding material is preferably configured to have an outer diameter of 20 to 50 mm and an inner diameter of the center hole of about 7 to 13 mm.

  On the other hand, from the viewpoint of reducing the residual liquid in the piping, as shown in FIG. 1, at least the inner peripheral surfaces of the non-metallic lining piping 2A and 2B and the inner peripheral surfaces of the sealing materials 12A and 12B are on the same plane. It is preferable to have a flush structure (that is, there is no level difference), and the inner peripheral surface of the non-metallic lining pipe, the inner peripheral surface of the sealing material, and the tip surface of the ground material are on the same surface. More preferably, it has a single structure. That is, the grounding material only needs to be arranged so that at least a part thereof is exposed in the ring of the sealing material.

  Moreover, as shown in FIG.1 and FIG.2A, it is preferable to form the convex part 18 so that the earth wire 14 can be connected to the outer peripheral side of the annular | circular shaped earth | ground material 4A. The shape of the convex portion 18 is not particularly limited as long as the ground wire 14 can be connected, but as shown in FIG. 2A, it is preferable to have a substantially rectangular shape having a width of 5 to 30 mm and a length of 15 to 50 mm.

  As the grounding material, it is also preferable to use a strip-shaped grounding material 4B as shown in FIGS. 3A and 3B. The shape of the strip-shaped ground material is not particularly limited as long as the tip of the ground material can protrude from the inner peripheral surface of the non-metallic lining pipe and the ground wire can be connected. For example, it is preferable to use a strip shape having a width of 5 to 50 mm and a length of 20 to 100 mm.

  The thickness of the annular ground material is preferably 0.1 to 100 mm, and more preferably 1 to 50 mm. The thickness of the strip-shaped ground material is preferably 0.1 to 50 mm, and more preferably 1 to 10 mm. By setting the thickness to 0.1 mm or more, an effect of sufficiently removing static electricity can be obtained. On the other hand, when the thickness is within 100 mm, the contact area between the ground material and the liquid material can be minimized, and the elution of the metal component into the photoresist polymer can be effectively prevented. The strip-shaped ground material preferably has a thickness of 50 mm or less in order to prevent liquid leakage.

  In the manufacturing method of the present invention, a grounding material is inserted into the connecting portion between the non-metallic lining pipes so as to come into contact with the liquid material to be fed. Normally, pipes for feeding liquid materials are formed with flange-like flange parts 10A and 10B at both ends thereof, as in the non-metallic lining pipes 2A and 2B shown in FIG. In a state of being sandwiched, the pipes can be connected by bringing the flange portions 10A and 10B into contact with each other and bolting or the like. Therefore, an earthing material may be inserted between the flange portions of the two pipes.

  In the example shown in FIG. 1, two annular sealing materials 12A and 12B are sandwiched between the flange portions 10A and 10B, and the grounding material 4A is inserted between the sealing materials 12A and 12B. Thus, by inserting the grounding material between the two sealing materials, it is possible to insert the grounding material while ensuring the liquid tightness of the pipe connection portion.

  The seal material and the ground material may be combined separately when used, but it is preferable to use a pipe connection packing in which the seal material and the ground material are integrated in advance. By using such a pipe connection packing, it becomes easy to assemble the pipe. For example, a pipe connection packing provided with an annular sealing material and a grounding material that is sandwiched between the sealing materials and disposed so that at least a part of the sealing material is exposed can be used.

  For example, the piping connection packing 20A shown in FIGS. 2A and 2B is sandwiched between the annular sealing materials 12A and 12B and the sealing materials 12A and 12B, which can come into contact with the flange surface of the piping, and the sealing materials 12A and 12B. A piping connection packing provided with a grounding material 4A arranged so as to protrude into the ring.

  3A and 3B is also sandwiched between the annular sealing materials 12C and 12D and the sealing materials 12C and 12D, which can come into contact with the flange surface of the piping, and the sealing materials 12C and 12D. It is an example of the packing for piping connection provided with the earth | ground material 4A arrange | positioned so that it may protrude in a ring.

  2A and 3A show examples of the packing for pipe connection in which the grounding materials 4A and 4B are configured to protrude into the rings of the sealing materials 12A to 12D. However, the tip surface of the grounding material is the sealing material. Those configured so as to have a flush structure with the inner peripheral surface are also preferable.

  The ground material is preferably inserted into at least a part of the plurality of pipes constituting the manufacturing apparatus, more preferably at least one place per 4 m of the pipe, and the plurality of pipes constituting the manufacturing apparatus. It is particularly preferable that it is inserted into all the connecting portions of the pipe.

[2] Overall configuration of the production method of the present invention:
Hereinafter, the whole structure of the manufacturing method of this invention is demonstrated, referring the manufacturing process flow of FIG.

[2-1] Polymerization step:
First, a polymerization reaction is performed in a state in which a polymerizable monomer is diluted in an appropriate solvent to synthesize a photoresist polymer. As shown in FIG. 4, a raw material 52 such as a polymerizable monomer is supplied to a reaction tank 50 in which a polymerization reaction is performed through a pipe 54. A reprecipitation tank 56 is connected to the reaction tank 50 by a pipe 58. The reaction tank 50 is connected to a storage pipe 60 for supplying a solvent. Therefore, in these pipes 54 and 58 and the storage pipe 60, a grounding material is inserted into the connecting part between the pipes, and the grounding is grounded, and the monomer, the polymerization initiator solution, the polymerization solvent, the polymerization liquid, etc. are sent. What is necessary is just to perform a liquid.

[2-1A] Monomer used as a raw material for the resist-forming polymer:
The polymerizable monomer includes an ethylenically unsaturated bond capable of constituting a repeating unit such as a radiation-sensitive polymer for resist formation and a polymer for forming an upper layer film or a lower layer film (antireflection film, etc.) in a multilayer resist. Examples thereof include polymerizable compounds.

  The “radiation-sensitive polymer for resist formation” includes at least a repeating unit (1) having a chemical structure that is decomposed by an acid and becomes alkali-soluble, and a polar group for enhancing adhesion to a substrate such as a semiconductor substrate. The repeating unit (2) is an essential unit, and if necessary, the repeating unit (3) includes a repeating unit (3) having a nonpolar substituent for adjusting the solubility in a solvent or an alkali developer.

  “Repeating unit (1)” has a chemical structure generally used as a resist from the past. For example, a nonpolar substituent is dissociated by an acid and a polar group soluble in an alkali developer is expressed. The chemical structure can be mentioned.

  The repeating unit (1) is obtained by polymerizing a monomer having a functional group (acid-dissociable alkali-soluble group) which is decomposed by an acid and becomes alkali-soluble, or (b) a monomer having an alkali-soluble group. Can be obtained by polymerizing and then protecting the alkali-soluble group with a functional group (acid-dissociable protecting group) that does not dissolve in an alkali and dissociates with an acid.

  (A) When a method of polymerizing a monomer having a functional group (acid-dissociable alkali-soluble group) that is decomposed by an acid and becomes alkali-soluble is used, such as a phenolic hydroxyl group, a carboxyl group, or a hydroxyfluoroalkyl group A non-polar acid-dissociable protecting group such as a tert-butyl group is bonded to the polymerizable compound having an alkali-soluble group, followed by polymerization.

Examples of the “polymerizable compound having an alkali-soluble group” include hydroxystyrenes such as p-hydroxystyrene, m-hydroxystyrene, and p-hydroxy-α-methylstyrene; acrylic acid, methacrylic acid, maleic acid, and 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-hexa) Fluoro-2-propyl) cyclohexyl) -1,1,1,3,3,3-hexafluoropropyl trifluoromethyl acrylate, 5- (2-hydroxy-1,1,1,3,3,3-hexafluoro And a polymerizable compound having a hydroxyfluoroalkyl group such as 2-propyl) methyl-2-norbornene;

Examples of the “nonpolar 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-butoxymethyl group, tert-butoxymethyl group, cyclopentyloxymethyl And oxygen-containing hydrocarbon groups such as a cyclohexyloxymethyl group, tricyclo [5.2.1.0 ^2,6 ] decanyloxymethyl group, and tert-butoxycarbonyl group.

  (B) A method in which a monomer having an alkali-soluble group is polymerized to obtain a polymer, and then the alkali-soluble group is protected with a functional group (acid-dissociable protecting group) that is not dissolved in an alkali and is dissociated by an acid. In the case of taking, the above-mentioned “polymerizable compound having an alkali-soluble group” is polymerized as it is, and the alkali-soluble group of the polymer is alkali-insoluble or hardly soluble such as vinyl ether and halogenated alkyl ether in the presence of an acid catalyst. An acid dissociable protecting group may be introduced by reacting with a compound that gives a substituent.

  Examples of the acid catalyst for introducing the acid-dissociable protecting group include p-toluenesulfonic acid, trifluoroacetic acid, and strongly acidic ion exchange resin.

  Examples of the compound giving “repeating unit (2)” include compounds having a phenolic hydroxyl group, a carboxyl group, a hydroxyfluoroalkyl group, etc. as polar groups. Specifically, the “polymerizable compound having an alkali-soluble group” described in the section of the repeating unit (1), a compound obtained by further substituting these compounds with a polar group, an alicyclic ring such as a norbornene ring or a tetracyclododecene ring Examples thereof include a polymerizable compound having a group having a polar group bonded to the structure.

As the “polar group”, a functional group containing a lactone structure is particularly preferable. For example, γ-butyrolactone, γ-valerolactone, δ-valerolactone, 1,3-cyclohexanecarbolactone, 2,6-norbornanecarbolactone, 4-oxatricyclo [5.2.1.0 ^2,6 ] decane. Examples thereof include functional groups containing a lactone structure such as -3-one and mevalonic acid δ-lactone.

  Examples of the “polar group” 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.

Examples of the compound giving “repeating unit (3)” include aromatic compounds having ethylenic double bonds such as styrene, α-methylstyrene, p-methylstyrene, and indene; acrylic acid, methacrylic acid, trifluoromethylacrylic 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. can be mentioned.

Examples of the “acid-stable nonpolar substituent” include methyl group, ethyl group, cyclopentyl group, cyclohexyl group, isobornyl group, 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.

  The monomer which gives repeating unit (1), (2) and (3) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The monomer charge ratio is not particularly limited as long as the basic performance as a resist is not impaired. Generally, it is preferable to charge so that the repeating unit (1) is 10 to 70 mol%, the repeating unit (2) is 30 to 90 mol%, and the repeating unit (3) is 0 to 50 mol%. It is more preferable to charge so that a unit (1) may be 10-60 mol%, a repeating unit (2) may be 40-90 mol%, and a repeating unit (3) may be 0-40 mol%.

  The polymer for forming the upper layer film / lower layer film includes a polymer composed of the repeating unit (2) and the repeating unit (3) among the repeating units constituting the resist forming polymer, that is, the repeating unit (1). There may be mentioned polymers having no structure. Such a polymer can be obtained, for example, by polymerizing a compound that gives the repeating unit (2) and a compound that gives the repeating unit (3), or by decomposing a resist-forming polymer with an acid. You can also.

  The monomer charge ratio is appropriately adjusted according to the purpose of use of the upper layer film and the lower layer film. Generally, it is preferable to charge so that a repeating unit (2) may be 10-100 mol% and a repeating unit (3) may be 0-90 mol%.

[2-1B] Monomer serving as a raw material for the polymer for forming the upper layer film / lower layer film:
When the upper layer film or the lower layer film is used as an antireflection film, the polymer for forming the upper layer film and the lower layer film is introduced with a crosslinking point and a chemical structure that absorbs radiation irradiated in photolithography. There is a need.

  As the “crosslinking point”, a reactive functional group capable of crosslinking by an ester bond, a urethane bond, or the like, for example, a reactive functional group such as a hydroxyl group, an amino group, a carboxyl group, or an epoxy group can be introduced. Examples of the monomer containing such a reactive functional group include hydroxystyrenes such as p-hydroxystyrene and m-hydroxystyrene; monomers having a reactive functional group introduced into the polymerizable compounds exemplified above. Can be used.

  The chemical structure that absorbs radiation depends on the wavelength of the radiation used. For example, for ArF excimer laser light, a chemical structure including a benzene ring and its analogs can be exemplified. 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; Examples thereof include aromatic ring-containing esters having an ethylenic double bond such as (meth) acrylate, optionally substituted naphthalene (meth) acrylate, and optionally substituted anthracenemethyl (meth) acrylate.

  The monomer having a chemical structure that absorbs radiation may be introduced as either the repeating unit (2) or the repeating unit (3). The composition ratio of the monomer having a chemical structure that absorbs radiation is preferably 10 to 100 mol%.

[2-1C] Reaction conditions, etc .:
The polymerization method is not particularly limited, and a known method such as solution polymerization can be used. For example, a polymerization initiator may be used, a chain transfer agent may be used as necessary, and the above-described polymerizable compound may be polymerized 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- And radical polymerization initiators such as organic peroxides such as trimethylhexanoyl) 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. Can be mentioned. 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 appropriately adjusted according to the production conditions such as the monomer used in the polymerization reaction, the polymerization initiator, the type of chain transfer agent, the polymerization temperature, the polymerization solvent, the polymerization method, and the purification conditions. be able to.

  Examples of the “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 solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although the usage-amount of a solvent is not specifically limited, Usually, it is preferable to set it as 0.5-20 mass parts with respect to 1 mass part of monomers, and it is more preferable to set it as 1-10 mass parts. If the amount of the solvent used is too small, the monomer may precipitate or the viscosity may be too high to keep the polymerization system uniform. On the other hand, if the amount of the solvent used is too large, the polymerization conversion rate of the monomer may be insufficient, or the molecular weight of the resulting polymer may not be increased to a desired value.

  The conditions for the polymerization reaction are not particularly limited, but the reaction temperature is usually 40 to 120 ° C, preferably 50 to 100 ° C. Moreover, reaction time is 1 to 48 hours normally, and it is preferable to set it as 1 to 24 hours.

  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 conversion weight average molecular weight (hereinafter also referred to as “Mw”) by gel permeation chromatography (GPC) is in the range of 2000 to 40000 by adjusting the polymerization reaction temperature or the amount of the polymerization initiator to be added. It is preferable to adjust so that it may become, and it is more preferable to adjust so that it may become the range of 3000-30000.

  As the reaction vessel, it is preferable to use a reaction vessel whose inner surface is coated with a glass lining layer containing a conductivity-imparting substance. As a polymerization solvent, even when using a solvent that easily generates static electricity by stirring, such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, methyl isobutyl ketone, propylene glycol monomethyl ether, ethyl lactate, propylene glycol monomethyl ether acetate, benzene, toluene, Generation | occurrence | production of static electricity can be relieved and a polymerization liquid can be prepared safely and efficiently.

  Examples of the “conductivity-imparting substance” include platinum, vanadium oxide, ruthenium oxide and the like. The glass lining layer can be formed by lining glass containing these components.

  In this polymerization step, the concentration (solid content concentration) of the resulting polymerization solution is preferably 1 to 80% by mass, more preferably 5 to 50% by mass, and 10 to 50% by mass. Further preferred. The solid content concentration can be adjusted, for example, by adjusting the addition amount of the polymerizable monomer or the solvent.

[2-2] Reprecipitation process:
Next, the polymer solution is dropped into a reprecipitation solvent such as a poor solvent to reprecipitate the polymer, thereby obtaining a photoresist polymer slurry. In this reprecipitation step, low molecular components such as residual monomers, dimers, trimers, and oligomers are removed, and the photoresist polymer is purified.

  As shown in FIG. 4, a reaction tank 50 and a filtration device 62 are connected to a reprecipitation tank 56 in which a reprecipitation step is performed by pipes 58 and 64. In addition, a storage pipe 66 for supplying a solvent is connected to the re-precipitation tank 56. Accordingly, in these pipes 58 and 64 and the storage pipe 66, a grounding material is inserted into the connecting part between the pipes, and the grounding is grounded, and a liquid solution such as a polymerization solution, a reprecipitation solvent, a polymer slurry for photoresist, etc. Can be done.

  The reprecipitation method is not particularly limited, and can be performed by a conventionally known method. For example, it can be carried out by dropping a polymerization solution whose concentration is adjusted as desired in a poor solvent. Further, the reprecipitation operation may be repeated twice or more using a good solvent to purify the polymer.

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

  The amount of the poor solvent used is not particularly limited, and may be appropriately selected depending on the kind of the poor solvent and the kind and content of the solvent contained in the polymerization solution. For example, it is preferable to use 0.5 to 50 times the poor solvent in terms of polymer mass with respect to the total amount of the polymerization solution, more preferably 1 to 30 times, and more preferably 2 to 20 times. preferable.

  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; Examples include ether esters such as methyl ether acetate, and lactones such as γ-butyrolactone. These good solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  Moreover, it is preferable to adjust the polymer slurry for photoresist obtained by this reprecipitation process so that the temperature may become 10-35 degreeC, and it is more preferable to adjust so that it may become 15-35 degreeC, It is still more preferable to adjust so that it may become -35 degreeC. The temperature of the slurry can be controlled by a temperature control device provided in the reprecipitation tank, the temperature of the poor solvent used, and the like.

[2-3] Filtration and re-dissolution process:
Further, the polymer slurry for photoresist is filtered to remove low molecular components.

  As shown in FIG. 4, a re-sink tank 56 is connected by a pipe 64 to a filtration device 62 in which a filtration process is performed. In addition, a storage pipe 70 for supplying a solvent is connected to the filtering device 62. Therefore, in the pipe 64 and the storage pipe 70, a ground material may be inserted into the connection portion between the pipes, and the polymer slurry for photoresist or the like may be fed in a state where the ground is grounded. After filtration, the photoresist polymer 68 is taken out and dissolved again by adding a solvent. This redissolution replaces the solvent with the solvent of the final product.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

Example 1
The piping for contacting the polymer solution, photoresist polymer slurry, and final product was a fluororesin lining piping. The inner diameter of the pipe was 13 mmφ. In the same manner as shown in FIGS. 1, 2A and 2B, the grounding material 4A was inserted into the flange portion corresponding to the connecting portion of these pipes, and the grounding wire 14 connected to the grounding material 4A was grounded. As the grounding material 4A, an annular material made of a tantalum plate having a thickness of 3 mm was used. The ground material 4A was configured to have an outer diameter of 40 mm and an inner diameter of the center hole of 13 mm. The convex part 18 was made into the substantially rectangular shape of width 20mm and length 40mm. The liquid feeding speed of the fluid in the piping in the manufacturing process was 1 to 5 m / s.

<Polymerization process>
32 kg of methyl ethyl ketone (MEK) as a polymerization solvent was charged into a 200 L polymerization tank equipped with a stirrer, thermometer, reflux cooling device, monomer solution dropping nozzle, initiator solution dropping nozzle, etc. After the replacement, the temperature was raised to 80 ° C. while stirring at 100 rpm. Thereafter, 5-methacryloyloxy-2,6-norbornanecarbolactone (NLM) 15 kg MEK solution, 2-methyl-2-adamantyl methacrylate (MAdMA) 20 kg MEK solution, azobisisobutyronitrile 0.5 kg MEK solution Were added dropwise over 3 hours. After completion of dropping, the mixture was further aged for 3 hours, and then cooled to room temperature to obtain a polymerization solution.

  As a result of measurement using high performance liquid chromatography, the monomer conversion rate of this polymerization solution was 90%, and the amount of residual monomer relative to 100% by mass of the polymer was about 11% 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 with the following method, molecular weight distribution (dispersion degree Mw / Mn) was 1.73.

[Mw, Mn, and Mw / Mn]:
Tosoh GPC columns (trade name “G2000HXL”, trade name “G3000HXL”, trade name “G4000HXL” 1), 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. Further, the degree of dispersion “Mw / Mn” was calculated from the measurement results of Mw and Mn.

<Reprecipitation process>
A re-precipitation tank equipped with a 200 L conductive glass lining layer was charged with 100 kg of methanol, and while stirring this at 150 rpm, 20 kg of the polymerization liquid (solid content concentration: about 25 mass%) was 12.5 g / min. The solution was dropped at a dropping speed of 1, and reprecipitation was performed. As a result, a white photoresist polymer slurry was obtained.

Thereafter, using a pressure filter with a fluororesin (registered trademark: Teflon) filter cloth (aeration rate: 3.0 cm ³ / cm ² · sec, filtration area: 1 m ² ) stretched on the bottom of the container, 0.2 MPa The photoresist polymer slurry was filtered under pressure with nitrogen pressure. Thereby, a polymer for photoresist (white solid) was obtained. Next, this white solid was put into 50 kg of propylene glycol monomethyl ether acetate (PGMEA) and dissolved for 1 hour to obtain a photoresist polymer solution (final product). The obtained photoresist polymer solution had no undissolved content and was a clear solution.

(Comparative Example 1)
A photoresist polymer solution was obtained in the same manner as in Example 1 except that no grounding material was inserted into the pipe.

  The polymer obtained in Comparative Example 1 was measured for weight average molecular weight (Mw) and number average molecular weight (Mn). As a result, the molecular weight distribution (dispersion degree Mw / Mn) was 1.74.

[Evaluation methods]
<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 was made to melt | dissolve in aqua regia and the amount of metal foreign materials was measured with the dielectric coupling plasma mass spectrometer (Brand name "ELAN DRC Plus", PerkinElmer company make). The metal species evaluated were Ta, Na, Ti, Ni, W, Fe, Cu, K, Li, Ba, Zn, Mg, B, Al, Co, Zr, Ca, Mn, Cr, and Mo. .

<Damage in container>
The state of breakage of the fluororesin lining piping in Example 1 and Comparative Example 1 was visually confirmed.

[Evaluation results]
The amount of metal foreign matter in the photoresist polymer solution obtained in Example 1 was less than the lower detection limit (ND = less than 0.5 ppb) for all measured metal species. Further, no damage was confirmed in the fluororesin lining piping used in Example 1.

  The amount of foreign metal 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. However, it was confirmed that the fluororesin lining piping was damaged by static electricity at 28 points.

  The method for producing a photoresist polymer of the present invention is a method for producing a photoresist polymer for use in fine processing such as strict sub-quarter micron level against contamination of foreign matters such as metallic foreign matters and impurities such as metal components. It is suitably used for production.

It is a schematic sectional drawing which shows one Embodiment of the piping structure of this invention, and is a figure which shows the cut surface which cut | disconnected the piping structure along the central axis of piping. It is a schematic plan view which shows one Embodiment of the packing for piping connection which makes a part of piping structure of this invention. It is a schematic sectional drawing which shows the cross section which cut | disconnected the packing for piping connection shown to FIG. 2A along the A-A 'line. It is a schematic plan view which shows another embodiment of the packing for piping connection which makes a part of piping structure of this invention. It is a schematic sectional drawing which shows the cross section which cut | disconnected the piping connection packing shown to FIG. 3A along the A-A 'line. It is process drawing which shows one Embodiment of the manufacturing method of this invention.

Explanation of symbols

1: Piping structure, 2A, 2B: Non-metallic lining piping, 4, 4A, 4B: Ground material, 6: Metal piping, 8: Lining, 10A, 10B: Flange, 12A, 12B, 12C, 12D: Sealing material, 14: ground wire, 16: center hole, 18: convex portion, 20A, 20B: packing for pipe connection, 50: reaction tank, 52: raw material, 54, 58, 64: piping, 60, 66, 70: storage piping, 62: Filtration device, 68: Product.

Claims (6)

It includes a step of feeding a liquid material through a plurality of non-metallic lining pipes,
For a photoresist, a ground material is inserted into a connection portion between the non-metallic lining pipes so as to be in contact with the liquid material to be fed, and the liquid material is fed while the ground material is grounded. A method for producing a polymer.   The manufacturing method according to claim 1, wherein the grounding material is made of at least one metal selected from the group consisting of stainless steel, tantalum, titanium, zirconium, and a nickel-base superalloy.   The method according to claim 1 or 2, wherein the liquid material is one of a photoresist polymer solution and a photoresist polymer slurry.   The manufacturing method according to any one of claims 1 to 3, wherein the liquid material includes at least one solvent selected from a saturated hydrocarbon solvent, a ketone solvent, and an acetate solvent. The saturated hydrocarbon solvent is pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane,
The ketone solvent is methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, 2-heptanone, cyclohexanone,
The production method according to claim 4, wherein the acetate solvent is ethylene glycol monomethyl ether acetate or propylene glycol monomethyl ether acetate. A plurality of non-metallic lining pipes are provided, and a pipe connecting packing is sandwiched between connecting parts of the non-metallic lining pipes,
An annular sealing material in which the packing for pipe connection can come into contact with the flange surface of the piping, and a grounding material disposed so as to be sandwiched between the sealing material and at least partially exposed in the ring of the sealing material A piping structure with

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