Filtration equipment, purification equipment, and chemical manufacturing methods

Abstract

To provide a filtration apparatus capable of producing chemical solution with excellent defect suppression performance, a purifier and a production method of chemical solution.SOLUTION: A filtration apparatus for purifying a purified solution to obtain chemical solution comprises an inflow part, an outflow part, a filter A, at least one filter B different from the filter A, and a distribution channel from the inflow part to the outflow part where the filter A and the filter B are arranged in series. The filter A is a porous film containing polyimide resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a filtering device, a purification device, and a method for producing a chemical solution.

[0002] During the manufacture of semiconductor devices through wiring formation processes including photolithography, chemical solutions containing water and / or organic solvents are used as pre-wet solutions, resist solutions (resist resin compositions), developers, rinse solutions, stripping solutions, chemical mechanical polishing (CMP) slurries, and post-CMP cleaning solutions, or as dilutions thereof. In recent years, advances in photolithography technology have led to advances in miniaturization of patterns. The chemicals used in such wiring formation processes are required to have further improved defect suppression performance. Such chemicals are generally thought to be obtained by purifying a to-be-purified liquid containing the components required for the chemical as its main components using a filter or the like to remove impurities.

[0003] As a method for producing such chemicals, Patent Document 1 describes "a method for producing a purified lithography chemical, comprising a filtration step of filtering a lithography chemical through a filter equipped with a polyimide resin porous membrane." Furthermore, Patent Document 2 describes "a method for purifying a liquid, comprising permeating a part or all of the liquid from one side to the other side of a polyimide and / or polyamideimide porous membrane having communicating pores by differential pressure." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-68261 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-155121 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have purified a liquid to be purified using the above-mentioned purification method to obtain a chemical solution, and evaluated the defect suppression performance of the chemical solution. They have found that sufficient defect suppression performance may not be obtained. Therefore, an object of the present invention is to provide a filtration device capable of producing a chemical solution with excellent defect suppression performance. Another object of the present invention is to provide a purification device and a method for producing a chemical solution. [Means for solving the problem]

[0006] As a result of extensive research into achieving the above object, the present inventors have found that the above object can be achieved by the following configuration.

[0007] [1] A filtration device for purifying a liquid to be purified to obtain a chemical solution, the filtration device having an inlet section, an outlet section, a filter A, at least one filter B different from filter A, and a flow path from the inlet section to the outlet section in which filter A and filter B are arranged in series, wherein filter A is a porous membrane containing a polyimide resin. [2] The filtration device according to [1], wherein the imidization rate of the polyimide resin is 1.0 or more. [3] The filtration device according to [1] or [2], wherein filter B is arranged downstream of filter A in the flow passage and includes at least one filter BD having a smaller pore size than filter A. [4] The filtration device according to [3], wherein the pore size of the filter BD is 20 nm or less. [5] The filtration device according to [3] or [4], wherein the filter BD contains at least one selected from the group consisting of polyethylene, nylon, and polytetrafluoroethylene. [6] The filtration device according to any one of [3] to [5], wherein the filter BD contains a second resin having a hydrophilic group. [7] The filtration device according to [1] or [2], wherein filter B is arranged upstream of filter A in the flow passage and includes at least one filter BU having a larger pore size than filter A. [8] The filtration device according to [7], wherein the pore size of the filter BU is 20 nm or more. [9] The filtration device according to any one of [1] to [8], wherein filter B includes at least one filter containing a resin having an ion exchange group, which is arranged upstream of filter A in the flow passage.

[10] The filtration device according to [9], wherein the ion exchange group is at least one selected from the group consisting of an acid group and a base group.

[11] The filtration device according to any one of [1] to

[10] , further comprising a tank disposed in series with the filter A on the flow path.

[12] The filtration device according to

[11] , further comprising a filter C having a pore size of 20 nm or less, arranged in series with the tank on the upstream side of the flow passage.

[13] A filtration device according to [1] or [2], having a return flow passage capable of returning the liquid to be purified from the downstream side of filter A to the upstream side of filter A on the flow passage.

[14] A filtration device described in any one of [3] to [6], having a return flow passage that can return the purified liquid from the downstream side of a reference filter consisting of any one of at least one filter BD to the upstream side of the reference filter.

[15] The filtration device according to any one of [1] to

[14] , wherein the chemical liquid is at least one selected from the group consisting of a developer, a rinse liquid, a wafer cleaning liquid, a line cleaning liquid, a pre-wet liquid, a wafer rinse liquid, a resist liquid, a liquid for forming an underlayer film, a liquid for forming an upper layer film, and a liquid for forming a hard coat, or at least one selected from the group consisting of an aqueous developer, an aqueous rinse liquid, a stripping liquid, a remover, an etching liquid, an acidic cleaning liquid, phosphoric acid, and a phosphoric acid-hydrogen peroxide aqueous mixture.

[16] The filtration device according to any one of [1] to

[15] , wherein the pH of the chemical solution is 0 to 9.

[17] A purification apparatus comprising the filtration apparatus according to any one of [1] to

[16] and at least one distiller connected to the inlet of the filtration apparatus.

[18] The purification apparatus according to

[17] , wherein the at least one distiller comprises a plurality of distillers connected in series.

[19] A method for producing a chemical solution, which comprises purifying a liquid to be purified to obtain a chemical solution, the method comprising a filtration step of purifying the liquid to be purified using the filtration device described in any one of [1] to

[16] to obtain the chemical solution.

[20] The method for producing a chemical solution according to

[19] , further comprising a filter washing step of washing the filter A and the filter B with a washing liquid before the filtration step.

[21] The method for producing a chemical solution according to

[19] or

[20] , further comprising an apparatus cleaning step of cleaning the liquid-contacting parts of the filtration apparatus with a cleaning liquid before the filtration step.

[22] The method for producing a chemical solution according to

[20] or

[21] , wherein the cleaning solution contains at least one selected from the group consisting of hydroxyaliphatic carboxylic acid esters, aliphatic carboxylic acid esters, linear or cyclic ketones, alkylene glycol monoalkyl ethers, alkylene glycol monoalkyl ether acetates, and aprotic polar solvents. [Effects of the Invention]

[0008] According to the present invention, a filtering device capable of producing a chemical solution having excellent defect suppression performance can be provided. The present invention also provides a purification device and a method for producing a chemical solution.

[0009] In this specification, the "defect suppression performance" of a chemical solution refers to the performance of the chemical solution evaluated by the method described in the Examples. Chemical solutions used in the manufacture of semiconductor substrates are required to have respective "defect suppression performance" according to the type and role of the chemical solution. In this specification, for chemical solutions used in forming resist films, such as prewet solutions, developers, and rinse solutions, the residue defects described in [Test Example 1] in the examples described later are considered to be one representative index value for defects in the lithography process, and the residue defect suppression performance is referred to as "defect suppression performance." Furthermore, for resist resin compositions containing resins and used in forming resist films, the bridge defects described in [Test Example 3] in the examples described later are considered to be one representative index value for defects in the lithography process that are caused by the resist resin composition, and the bridge defect suppression performance is referred to as "defect suppression performance." Furthermore, for chemical solutions used as etching solutions, resist strippers, and the like, the particle defects described in [Test Example 2] in the examples described later are considered to be one representative index value for defects caused by the chemical solutions, and the particle defect suppression performance is referred to as "defect suppression performance." Hereinafter, when simply referring to "defect suppression performance," it means the respective defect suppression performance according to the type of chemical liquid (residue defect suppression performance, bridge defect suppression performance, or particle defect suppression performance). [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a filtering device according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic diagram illustrating a filtering device according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic diagram illustrating a modified example of the filtering device according to the second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram illustrating a filtering device according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram illustrating a modified example of the filtering device according to the third embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram illustrating a filtering device according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a schematic diagram illustrating a filtering device according to a fifth embodiment of the present invention. [Figure 8] FIG. 10 is a schematic diagram illustrating a modification of the filtering device according to the fifth embodiment of the present invention. [Figure 9] FIG. 10 is a schematic diagram illustrating a filtering device according to a sixth embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram illustrating a modification of the filtering device according to the sixth embodiment of the present invention. [Figure 11] 1 is a schematic diagram showing the relationship between the various devices when a liquid drug is produced using a distilled purified liquid that has been previously purified in a distiller. [Figure 12] 1 is a schematic diagram illustrating a purification device according to a first embodiment of the present invention. [Figure 13] FIG. 2 is a schematic diagram illustrating a purification device according to a second embodiment of the present invention. [Figure 14] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 15] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 16] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 17] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 18] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 19] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 20] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 21] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 22] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 23] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 24] FIG. 1 is a schematic diagram showing a purification device according to the prior art. [Figure 25] FIG. 1 is a schematic diagram illustrating a filtering device according to the prior art. [Figure 26] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 27] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. [Figure 28] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 29] 1 is a schematic diagram illustrating a purification device according to an embodiment of the present invention. [Figure 30] 1 is a schematic diagram illustrating a filtering device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] [Filtration equipment] A filtration device according to an embodiment of the present invention is a filtration device having an inlet section, an outlet section, filter A, at least one filter B different from filter A, and a flow path (path through which the liquid to be purified flows) from the inlet section to the outlet section in which filter A and filter B are arranged in series (in other words, a filtration device having a flow path from the inlet section to the outlet section in which filter A and at least one filter B different from filter A are arranged in series between the inlet section and the outlet section), in which filter A is a porous membrane containing a polyamide-imide resin (in other words, filter A is a porous membrane containing a polyamide-imide resin as a component (material component) that constitutes its material).

[0013] In general, impurities in a chemical solution that are related to the defect suppression performance of the chemical solution are expected to include, for example, gel-like organic compound (particularly polymer compound) components, inorganic fine particles, inorganic ions, and the like. Of these, gel-like polymer compounds or inorganic fine particles that may become solids in the chemical solution are likely to be easily removed by the sieving effect of the filter, resulting in improved defect suppression performance of the resulting chemical solution. On the other hand, inorganic components other than particles and ionic components are easily removed by the adsorption function of the filter (adsorption by ionic interactions, adsorption by hydrophilic-hydrophobic interactions, etc.), and as a result, it is expected that the defect suppression performance of the resulting chemical solution will be improved.

[0014] The present inventors have discovered for the first time that arranging a filter having a sieving effect and a filter having an adsorption effect in series in the flow path of a filtration device results in a chemical solution with better defect suppression performance than the chemical solution obtained when each filter is used alone. The present inventors speculate that the mechanism by which this result was obtained is as follows.

[0015] According to the investigations of the present inventors, it has become clear that defects may occur due to the interaction between a microgel (containing an organic compound) that would not be a source of defects by itself and inorganic fine particles and / or inorganic ions, the interaction between a gel-like organic compound and microinorganic fine particles and trace metals, etc. that would not be a source of defects by itself, and the interaction between a microgel and microinorganic fine particles and trace metals, etc. In particular, microgels cannot be fully removed by filtration using the molecular sieve effect due to the effects of solvation in the chemical solution, and after the chemical solution is applied to the wafer, the effects of solvation are reduced when the wafer is dried, causing the gel to form, which is thought to be one of the causes of defects.

[0016] For such complex defect sources, it is effective to remove each of the interacting causative components, and it is expected that removing the microgel components, inorganic ultrafine particle components that may interact with the microgel components, and inorganic ion components through the sieving effect and adsorption effect will lead to a further reduction in defects.

[0017] The filtering device according to the embodiment of the present invention improves the efficiency of removing defects caused by multiple factors due to the ion capturing effect of Filter A, which is a porous membrane containing polyimide resin as a material component, and the effect of removing gel-like microparticles and inorganic microparticles by the combined Filter B, and as a result, it is believed that a chemical solution with excellent defect suppression performance is obtained. In the filtration device according to an embodiment of the present invention, filters A and B are arranged in series on the flow path, so that the liquid to be purified is filtered sequentially by filters A and B (or filters B and A). The filtration device according to an embodiment of the present invention will be described below. In the following description, a filtration device of the total volume filtration type (dead-end type) in which the entire amount of the liquid to be purified introduced into the filter is filtered through the filter is exemplified. However, the filtration device according to an embodiment of the present invention is not limited to the above, and may be a cross-flow type filtration device in which the introduced liquid to be purified is separated into a purified liquid to be purified and a concentrated liquid (and the concentrated liquid may be introduced into the filter again as the liquid to be purified), or a combination of these types. The above filtration device will be described below with reference to the drawings.

[0018] First Embodiment FIG. 1 is a schematic diagram illustrating a filtering device according to a first embodiment of the present invention. The filtration device 100 is a filtration device in which a filter 103, which is filter A, and a filter 104 (filter BD) having a smaller pore size than the filter 103 are connected in series via a pipe 105 between an inlet section 101 and an outlet section 102. The inlet section 101, filter 103, piping 105, filter 104, and outlet section 102 are configured so that the liquid to be purified can flow through each of them, and the above components are connected to form a flow path S1 (a path through which the liquid to be purified flows).

[0019] The inlet 101 and outlet 102 are not particularly limited in form as long as they can introduce the liquid to be purified into the filtration device and discharge it, but typical examples include hollow cylindrical pipes (inlet and outlet) having an inlet and an outlet. The following description will be given taking as an example a form in which the outlet and inlet are each pipes. The shapes of inlet portion 101, pipe 105, and outlet portion 102 are not particularly limited, but typically include a hollow cylindrical shape formed so that the liquid to be purified can flow through the inside. The material components of these are not particularly limited, but it is preferable that the liquid-contacting parts (parts that may come into contact with the liquid to be purified when filtering the liquid) are made of a corrosion-resistant material described below.

[0020] The liquid to be purified introduced from inlet 101 of filtration device 100 flows through filtration device 100 along flow path S1, is filtered sequentially by filter 103 (filter A) and filter 104 (filter BD), and is then discharged from outlet 102 to the outside of filtration device 100. The form of the liquid to be purified will be described later. In addition, the filtration device 100 may have pumps, dampers, valves, etc. (not shown) on the flow path S1 (e.g., the inlet section 101, the piping 105, and the outlet section 102, etc.) for the purpose of circulating the liquid to be purified.

[0021] The shape of filter 103 (filter A) and filter 104 (filter B) is not particularly limited. Examples of the shape of filter A and filter B include planar, pleated, spiral, and hollow cylindrical shapes. Among these, a cartridge filter shape having a core material made of a material permeable to the liquid to be purified and / or a structure permeable to the liquid to be purified, and a filter wound around the core material and disposed on the core material, is typically preferred, as it is easier to handle. In this case, the material of the core material is not particularly limited, but it is preferably formed from a corrosion-resistant material, which will be described later.

[0022] Although there are no particular limitations on the method of arranging the filter, it is typically preferred that the filter be arranged in a housing (not shown) that includes at least one inlet and at least one outlet, with at least one flow path formed between the inlet and outlet. In this case, the filter is arranged so as to cross the flow path within the housing. The flow path formed within the housing forms a part of flow path S1, and the liquid to be purified is filtered by the filter arranged so as to cross flow path S1 as it flows through flow path S1.

[0023] The housing material can be any suitable rigid, impermeable material, including any impermeable thermoplastic material that is compatible with the liquid to be purified. For example, the housing can be made of a metal, such as stainless steel, or a polymer. In some embodiments, the housing is a polymer, such as polyacrylate, polypropylene, polystyrene, or polycarbonate. Furthermore, in order to obtain a filtration device having even better effects of the present invention, it is preferable that at least a portion of the liquid-contacting part of the housing, preferably 90% of the surface area of ​​the liquid-contacting part, and more preferably 99% of the surface area of ​​the liquid-contacting part, be made of a corrosion-resistant material as described below. Note that in this specification, the liquid-contacting part means a part that may come into contact with the liquid to be purified (excluding the filter itself), and refers to the inner wall of a unit such as a housing.

[0024] <Filter A> Filter A is a porous membrane containing a polyimide resin as a material component. In this specification, "polyimide resin" refers to polyimide and polyamideimide, and Filter A may contain at least one selected from the group consisting of polyimide and polyamideimide as a material component. The polyimide resin may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and an -NH- bond.

[0025] Filter A is a porous membrane containing a polyimide resin as a material component, and Filter A may be a porous membrane made of a polyimide resin, or may be a porous membrane containing a material component other than a polyimide resin. When filter A contains a material component other than a polyimide resin, it is typically a porous membrane made of a laminate having a layer containing a polyimide resin and a layer containing another material (e.g., nylon, polytetrafluoroethylene, and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.).

[0026] Filter A is a porous membrane with many pores within the membrane. The structure of these pores (pore structure) is not particularly limited, but it is preferable that the filter A has interconnected pores formed by many interconnected spherical pores. Furthermore, it is preferable that filter A has a flow path for the purified liquid formed by the interconnected pores. The method for forming a porous film having such a pore structure is not particularly limited, but it can typically be formed by forming a composite film of a polyimide resin and fine particles, and then removing the fine particles. In this way, continuous pores are likely to be formed in the composite film at the portions where the fine particles were in contact with each other. The method for producing such a porous film will be described later. When the liquid to be purified flows through the communication holes, impurities are removed from the liquid to be purified by separation and / or adsorption.

[0027] The communicating holes may be formed by individual holes (hereinafter sometimes simply referred to as "holes") that impart porosity to filter A, and the holes are preferably holes having a curved inner surface as described below, and more preferably approximately spherical holes as described below. In filter A, it is preferable that the portions where the individual holes are adjacent to each other form communicating holes, and that the holes have a structure in which they are interconnected. It is also preferable that a plurality of holes are connected, and that the connected holes form a flow path for the liquid to be purified when viewing filter A as a whole. In this case, the flow passage is preferably formed by connecting the individual "holes" and / or "communicating holes". Typically, the individual pores are preferably pores formed by removing individual particles present in the polyimide resin-particle composite membrane in a later step in the method for producing filter A, which will be described later. The communicating pores may also be adjacent individual pores formed by removing the particles in a later step at the locations where individual particles present in the polyimide resin-particle composite membrane were in contact with each other in the method for producing a polyimide resin porous membrane, which will be described later.

[0028] Filter A preferably contains interconnected pores having a B value of 15 nm or less, as determined by the method described below. According to the manufacturing method described below, one interconnected pore is typically formed from two adjacent particles. In this case, the pore diameter may be the diameter in a direction perpendicular to the longitudinal direction, where the direction in which two adjacent pores making up the interconnected pores are connected is taken as the longitudinal direction. The pore diameters of the interconnected pores, formed by adjacent pores, tend to be smaller when the pore diameter distribution of the individual pores that impart porosity to filter A is broad.

[0029] In this specification, the term "B value" refers to a number (unit: nm) calculated by the following method. First, the adsorption isotherm is determined by adsorbing and desorbing adsorbed molecules onto filter A. Then, from the obtained adsorption isotherm, [P / {V a (P0-P)} is calculated and plotted against the equilibrium relative pressure (P / P0). This plot is then considered as a straight line, and the slope s (= [(C-1) / (V m C)]) and intercept i(=[1 / (V m Then, V is calculated based on the obtained slope s and intercept i according to equations (2-1) and (2-2). m and C are calculated. m The specific surface area A is calculated based on the formula (3). Next, the adsorption data of the obtained adsorption isotherm is linearly interpolated to determine the adsorption amount at the relative pressure set as the pore volume calculation relative pressure. The total pore volume V is calculated from this adsorption amount. This is based on the theory of a series of calculation methods for specific surface area generally known as the "Brunauer, Emmett, Teller (BET) method." When carrying out the above method, matters not described in this specification shall be in accordance with JIS R 1626-1996 "Method for measuring the specific surface area of ​​fine ceramic powders by the gas adsorption BET method."

[0030] [P / {V a (P0-P)}] =[1 / (V m ·C)]+[(C-1) / (V m ·C)](P / P0) (1) V m =1 / (s+i) (2-1) C=(s / i)+1 (2-2) A=(V m ·L·σ) / 22414 (3)

[0031] however, V a :Adsorption amount V m : Monolayer adsorption amount P: Pressure at equilibrium of adsorbed molecules P0: Saturated vapor pressure of adsorbed molecules L: Avogadro's number σ: Adsorption cross section of the adsorbed molecule.

[0032] The B value (nm) is a value calculated from the specific surface area A and the total pore volume V calculated by the above method using the formula [4V / A] based on the obtained specific surface area A and total pore volume V. The B value (nm) represents the pore diameter estimated from the measurement results of the BET method.

[0033] When filter A has the above-mentioned communicating holes, when the liquid to be purified is passed through filter A, the liquid can pass through the inside of filter A. Filter A preferably has an internal flow path in which individual holes, each having a curved inner surface, are connected by communicating holes.

[0034] As described above, filter A is preferably a porous membrane containing pores having curved inner surfaces, and more preferably, most (preferably substantially all) of the pores in the porous membrane are formed with curved surfaces. In this specification, the phrase "having a curved inner surface" in reference to pores means that at least the inner surfaces of the pores that create porosity have a curved surface in at least a portion of the inner surface.

[0035] It is preferable that at least the inner surfaces of the pores in filter A are substantially entirely curved, and such pores may be referred to as "approximately spherical pores" hereinafter. In this specification, "approximately spherical pores" refer to pores whose inner surfaces form an approximately spherical space. Approximately spherical pores are likely to be formed when the microparticles used in the manufacturing method described below are approximately spherical. As used herein, the term "approximately spherical" refers to a particle having a sphericity of 1±0.3 or less, which is defined as the sphericity obtained by dividing the major axis by the minor axis of the particle. The approximately spherical pores in filter A preferably have a sphericity of 1±0.1 or less, and more preferably 1±0.05 or less.

[0036] The pores in the porous membrane have curved inner surfaces, so that when the liquid to be purified is passed through filter A, the liquid can be sufficiently distributed inside the pores of filter A and can be in sufficient contact with the inner surfaces of the pores, and in some cases, convection may occur along the curved inner surfaces. The substantially spherical pores may further have recesses on their inner surfaces. The recesses may be formed, for example, by pores having openings on the inner surfaces of the substantially spherical pores and having a smaller pore diameter than the substantially spherical pores.

[0037] Preferably, filter A has a structure in which substantially spherical pores having an average spherical diameter of 2000 nm or less are interconnected. The average spherical diameter of the substantially spherical pores is preferably 600 nm or less, more preferably 500 nm or less. When the average sphericity is in the range of 600 nm to 2000 nm, the particle size distribution index (d25 / 75) of the fine particles described below is preferably 1.6 to 5, more preferably 2 to 4. When the average sphericity is 600 nm or less, the particle size distribution index (d25 / 75) of the fine particles described below is preferably 1 to 5, more preferably 1.1 to 4. For those subjected to the chemical etching treatment described below, the average spherical diameter of the substantially spherical pores is determined by measuring the change in the average interconnected pore size using a porometer, and then calculating the actual average spherical diameter of the substantially spherical pores from this value. However, for those not subjected to the chemical etching treatment, such as polyamideimide, the average particle size of the fine particles used in producing the porous membrane can be used as the average spherical diameter of the substantially spherical pores.

[0038] Filter A contains a polyimide resin as a material component, and may also contain other resins. The resin content in the material components of filter A is not particularly limited, but is generally preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more, relative to the total mass of filter A. Filter A may also be substantially made up of resin alone. "Made up of resin alone" means that the material components consist solely of resin, excluding unintentionally mixed impurities.

[0039] The polyimide resin may have at least one substituent selected from the group consisting of a carboxy group, a salt-type carboxy group, and an —NH— bond. The polyimide resin is preferably a polymer having the above-mentioned substituent at a position other than the main chain end. Examples of the polymer having the above-mentioned substituent at a position other than the main chain end include polyamic acid.

[0040] In this specification, the term "salt-type carboxy group" refers to a group in which a hydrogen atom in a carboxy group is substituted with a cationic component. The "cation component" may be a cation itself in a completely ionized state, or a -COO- The cationic component may be ionically bonded to the cation and be in a state where it is virtually uncharged, or may be in an intermediate state between the two and have a partial charge. When the "cation component" is an M ion component consisting of an n-valent metal M, the cation itself is M n+ The cation component is expressed as "-COOM 1 / n " is the element represented by "M" in ".

[0041] The "cation component" is not particularly limited, but generally includes an ion component or an organic alkali ion component. For example, when the alkali metal ion component is a sodium ion component, the cation itself is a sodium ion (Na + ) and the cationic component is the element represented by "Na" in "-COONa". The cationic component with partial charge is Na δ+ is. The cationic component is not particularly limited, and may be an inorganic component; NH4 + , N(CH3)4 + Examples of inorganic components include metal elements such as alkali metals such as Li, Na, and K; alkaline earth metals such as Mg and Ca; and the like. Examples of organic components include organic alkali ion components such as NH4 + , e.g. NR4 + (All four R's represent organic groups and may be the same or different.) The organic group represented by R is preferably an alkyl group, more preferably an alkyl group having 1 to 6 carbon atoms. Examples of quaternary ammonium cations include N(CH3)4 + etc.

[0042] The state of the cationic component in the salt-type carboxy group is not particularly limited. In general, the state of the cationic component can change depending on the environment in which the polyimide resin exists, for example, whether it is in an aqueous solution, an organic solvent, or dry. When the cationic component is a sodium ion component, for example, in an aqueous solution, it is -COO - and Na + If it is in an organic solvent or is dry, -COONa may not dissociate.

[0043] The polyimide resin may have at least one substituent selected from the group consisting of a carboxy group, a salt-type carboxy group, and an -NH- bond. When the polyimide resin has at least one of these, it usually has both a carboxy group and / or a salt-type carboxy group and an -NH- bond. With regard to the carboxy group and / or the salt-type carboxy group, the polyimide resin may have only a carboxy group, only a salt-type carboxy group, or both a carboxy group and a salt-type carboxy group. The ratio of carboxy groups to salt-type carboxy groups in a polyimide resin may vary depending on, for example, the environment in which the polyimide resin exists, even for the same polyimide resin, and is also affected by the concentration of cationic components.

[0044] In the case of polyimide, the total number of moles of carboxy groups and salt-type carboxy groups contained in the polyimide resin is usually equimolar to the number of --NH-- bonds. In particular, in the method for producing a porous polyimide film described below, when carboxy groups and / or salt-type carboxy groups are formed from part of the imide bonds in the polyimide, -NH- bonds are also formed substantially simultaneously, and the total number of moles of the formed carboxy groups and salt-type carboxy groups is equimolar to the number of -NH- bonds formed. In the case of a method for producing a polyamideimide porous film, the total number of moles of carboxy groups and salt-type carboxy groups in the polyamideimide is not necessarily equimolar to the —NH— bond, and depends on the conditions of chemical etching in the etching (ring-opening of imide bonds) step described below.

[0045] The polyimide resin preferably has at least one type of unit selected from the group consisting of repeating units (hereinafter simply referred to as "units") represented by the following general formulas (1) to (4). Of the polyimide-based resins, the polyimide preferably has at least one unit selected from the group consisting of a unit represented by the following general formula (1) and a unit represented by the following general formula (2). Among the polyimide-based resins, the polyamideimide preferably has at least one unit selected from the group consisting of a unit represented by the following general formula (3) and a unit represented by the following general formula (4).

[0046] [ka]

[0047] [ka]

[0048] In formulas (1) to (3), X 1 ~X 4 may be the same or different and each independently represents a hydrogen atom or the above-described cation component. R Ar is an aryl group, and in the unit represented by formula (5) constituting the polyamic acid described later or the unit represented by formula (6) constituting the aromatic polyimide, R Ar The aryl group may be the same as the aryl group represented by the following formula: Y 1 ~Y 4 are each independently a divalent residue of a diamine compound excluding an amino group, and are each an R' to which N is bonded in a unit represented by formula (5) constituting a polyamic acid described below or a unit represented by formula (6) constituting an aromatic polyimide. Ar The arylene group may be the same as the arylene group represented by the following formula:

[0049] The polyimide resin may be one in which a portion of the imide bonds (-N[-C(=O)]2) in a general polyimide or polyamideimide is ring-opened to have units represented by the above general formula (1) or (2) in the case of polyimide, or units represented by the above general formula (3) in the case of polyamideimide.

[0050] The polyimide-based resin porous membrane may contain a polyimide-based resin having at least one substituent selected from the group consisting of a carboxy group, a salt-type carboxy group, and an —NH— bond, which is formed by ring-opening a portion of the imide bonds.

[0051] The unchanged rate when a part of the imide bonds is opened can be determined by the following steps (1) to (3). Step (1): When the etching step (opening of the imide bond) described below is not performed, the value (X01) is calculated by dividing the area of ​​the peak representing the imide bond measured by a Fourier transform infrared spectrometer by the area of ​​the peak representing benzene measured by the Fourier transform infrared spectrometer for the porous film (however, when the varnish for producing the porous film contains polyamic acid, the imidization reaction is considered to be substantially completed in the step of baking the composite film before baking). Step (2): A porous film obtained using the same polymer (varnish) as the porous film for which X01 was determined is subjected to the etching process (ring-opening of imide bonds) described below. The porous film is then measured using a Fourier transform infrared spectrometer and the area of ​​the peak representing imide bonds is divided by the area of ​​the peak representing benzene, also measured using a Fourier transform infrared spectrometer, to determine the value (X02). Step (3): Calculate the unchanged rate using the following formula. Unchanged rate (%) = (X02) ÷ (X01) × 100

[0052] The rate of change in the porous film is preferably 60% or more, more preferably 70 to 99.5%, and even more preferably 80 to 99%. In the case of a porous film containing polyamideimide, since it contains --NH-- bonds, the rate of change may be 100%.

[0053] In the case of a polyimide porous film, the "imidization ratio" is the value obtained by dividing the area of ​​the peak representing the imide bond measured by an FT-IR (Fourier transform infrared spectrometer) by the area of ​​the peak representing benzene also measured by the FT-IR. The imidization rate (X02) determined in the above step (2) is not particularly limited, but is preferably 1.0 or more. 1 / 2 When the solubility parameter of the purified liquid described later is 20 (MPa), the imidization ratio is more preferably 1.0 to 1.5. 1 / 2 If the pressure is more than 30 MPa, the upper limit is not particularly limited. 1 / 2 The imidization ratio is preferably greater than 1.5. In this case, the upper limit is not particularly limited, but is generally preferably 2.0 or less.

[0054] (Production method of filter A) Although there are no particular limitations on the method for producing filter A according to this embodiment, it is preferable to include a step of forming carboxy groups and / or salt-type carboxy groups from some of the imide bonds in the polyimide and / or polyamideimide (hereinafter referred to as the "etching step"). When carboxy groups and / or salt-type carboxy groups are formed from some of the imide bonds in the etching step, theoretically equimolar -NH- bonds are also formed substantially simultaneously with these groups.

[0055] When the resin contained in filter A is substantially polyamideimide, filter A already has -NH- bonds and exhibits good adsorption power for foreign matter in the purified liquid even without undergoing an etching step. In such a case, the method for producing filter A may or may not include an etching step.

[0056] The method for producing the filter A preferably involves producing a molded film containing polyimide and / or polyamideimide as the main component (hereinafter sometimes abbreviated as "polyimide-based resin molded film"), followed by an etching step. The polyimide resin formed film to be subjected to the etching process may be porous or non-porous. The form of the polyimide resin formed film is not particularly limited, but it is preferably a thin form such as a film, in order to increase the degree of porosity in the obtained polyimide resin porous film, and more preferably it is porous and thin form such as a film.

[0057] As described above, the polyimide resin film may be non-porous when subjected to the etching step, but in this case, it is preferable to make it porous after the etching step. As a method for making a polyimide-based resin molded film porous before or after the etching step, a method including a particle removal step is preferred in which the film is made porous by removing the particles from a composite film of polyimide and / or polyamideimide and particles (hereinafter referred to as a "polyimide-based resin-particle composite film").

[0058] The method for producing the filter A includes the following production method (a) or production method (b). Production method (a): A method including a step of etching a composite film of polyimide and / or polyamideimide and fine particles before the fine particle removal step. Manufacturing method (b): A method including a step of etching the polyimide resin film made porous by the particle removal step after the particle removal step. Among these, the latter production method (b) is preferred because it allows the degree of porosity of the resulting filter A to be increased.

[0059] A typical example of a method for manufacturing the filter A according to this embodiment will be described below.

[0060] The filter A according to this embodiment is typically formed using a varnish prepared by the following method: The varnish is prepared by mixing a microparticle dispersion, in which microparticles are previously dispersed in an organic solvent, with polyamic acid, polyimide, or polyamide-imide in any ratio, or by polymerizing a tetracarboxylic dianhydride and a diamine in the microparticle dispersion to form polyamic acid, or by further imidizing the polyamic acid to form polyimide.

[0061] The viscosity of the varnish is preferably 300 to 2000 cP (0.3 to 2 Pa·s), more preferably 400 to 1800 cP (0.4 to 1.8 Pa·s). When the viscosity of the varnish is within the above range, a more uniform film can be formed. The viscosity of the varnish can be measured at a temperature of 25°C using an E-type rotational viscometer.

[0062] The mass ratio of the polyimide resin to the fine particles (preferably resin fine particles) in the varnish is not particularly limited. The (resin) fine particles and the polyamic acid, polyimide, or polyamideimide are mixed so that when the varnish is baked (or dried if baking is optional) to form a polyimide resin-fine particle composite film, the mass ratio of the fine particles to the polyimide resin (ratio of fine particles / polyimide resin) is preferably 1 to 4 (mass ratio), more preferably 1.1 to 3.5 (mass ratio).

[0063] The volume ratio of the polyimide resin to the fine particles in the varnish is not particularly limited. When the varnish is used to form a polyimide resin-fine particle composite film, the fine particles and the polyamic acid, polyimide, or polyamideimide are mixed so that the volume ratio of the fine particles to the polyimide resin is preferably 1.1 to 5, more preferably 1.1 to 4.5.

[0064] When the mass content ratio or volume content ratio is equal to or greater than the preferred lower limit of the range, pores with an appropriate density for a porous membrane can be easily obtained, and when the mass content ratio or volume content ratio is equal to or less than the preferred upper limit of the range, the varnish viscosity is likely to be appropriate, and a uniform membrane can be more stably produced. In this specification, the volume ratios are values ​​at 25°C.

[0065] The material of the fine particles contained in the varnish is not particularly limited, but it is preferable that the material is insoluble in the organic solvent used in the varnish and can be selectively removed after film formation. Examples of materials for the fine particles include silica (silicon dioxide), titanium oxide, alumina (Al2O3), calcium carbonate, etc. Other examples include high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene, acrylic resins (methyl methacrylate, isobutyl methacrylate, polymethyl methacrylate (PMMA), etc.), epoxy resins, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polyether, polyethylene, etc. Among these, silica such as colloidal silica is preferred as the inorganic material, since it is easy to form minute pores with curved inner surfaces in the porous film, and acrylic resins such as PMMA are preferred as the organic material.

[0066] The resin particles can be selected from, for example, ordinary linear polymers and / or known depolymerizable polymers depending on the purpose, without any particular limitation. Ordinary linear polymers are polymers whose molecular chains are randomly cleaved upon thermal decomposition. Depolymerizable polymers are polymers that are decomposed into monomers upon thermal decomposition. Any of these polymers can be removed from the polyimide resin film by being decomposed into monomers, low molecular weight polymers, or CO2 upon heating.

[0067] Among depolymerizable polymers, methyl methacrylate or isobutyl methacrylate alone (polymethyl methacrylate or polyisobutyl methacrylate), which have a low thermal decomposition temperature, or a copolymer containing these as the main component, is preferred from the viewpoint of handling during pore formation.

[0068] The decomposition temperature of the resin fine particles is preferably 200 to 320°C, more preferably 230 to 260°C. If the decomposition temperature is 200°C or higher, film formation is possible even when a high-boiling point solvent is used in the varnish, and the range of baking conditions for the polyimide resin can be broadened. If the decomposition temperature is 320°C or lower, only the resin fine particles can be easily eliminated without causing thermal damage to the polyimide resin.

[0069] The fine particles preferably have a high sphericity, since the inner surfaces of the pores in the porous film to be formed are likely to have curved surfaces. The particle size (average diameter) of the fine particles used is, for example, preferably 5 to 2000 nm, more preferably 10 to 600 nm. If the average diameter of the microparticles is within the above range, when the liquid to be purified is passed through the filter A of this embodiment obtained by removing the microparticles, the liquid to be purified can be brought into even contact with the inner surfaces of the pores of the filter A, and impurities in the liquid to be purified can be adsorbed efficiently.

[0070] The particle size distribution index (d25 / d75) of the fine particles is preferably 1-6, more preferably 1.6-5, and even more preferably 2-4. When the particle size (average diameter) of the fine particles is 600 nm or less, d25 / 75 is preferably from 1 to 5, more preferably from 1.1 to 4. The fine particles may be used alone or in combination of two or more kinds. If the particle size distribution index is equal to or greater than the lower limit of the above range, the microparticles can be efficiently packed inside the porous membrane, making it easier to form flow paths within filter A and to adjust the flow rate when the liquid to be purified is passed through. On the other hand, if the particle size distribution index is equal to or less than the upper limit of the above range, pores of different sizes are more likely to be formed, which causes different convection currents when the liquid to be purified is passed through, making it easier to further improve the adsorption rate of foreign matter. It should be noted that d25 and d75 are particle diameter values ​​at which the cumulative frequency of the particle size distribution is 25% and 75%, respectively, and in this specification, d25 is the larger particle diameter.

[0071] In the "Formation of Unbaked Composite Film" described later, when the unbaked composite film is formed as a two-layer film, the fine particles (B1) used in the first varnish and the fine particles (B2) used in the second varnish may be the same or different. The pore structure can be adjusted by controlling the particle size, shape, particle size distribution index, etc. of the fine particles B1 and B2.

[0072] Specifically, in order to make the pores on the side in contact with the substrate denser, it is preferable that the particle size distribution index of the fine particles (B1) is smaller than or equal to that of the fine particles (B2). Furthermore, the fine particles (B1) preferably have a sphericity smaller than or equal to that of the fine particles (B2). The particle size (average diameter) of the fine particles (B1) is preferably smaller than that of the fine particles (B2), and it is particularly preferred to use fine particles (B1) having a particle size of 100 to 1000 nm (more preferably 100 to 600 nm) and fine particles (B2) having a particle size of 500 to 2000 nm (more preferably 700 to 2000 nm). By using fine particles (B1) having a particle size smaller than that of the fine particles (B2), the opening ratio of the pores on the surface of the obtained polyimide-based resin porous membrane can be increased and the diameters can be made uniform, and the strength of the entire polyimide-based resin porous membrane can be increased compared to when the entire polyimide-based resin porous membrane is made of fine particles (B1) alone.

[0073] In this specification, a dispersant may be added to the varnish together with the fine particles to uniformly disperse the fine particles. The addition of a dispersant allows the polyamic acid, polyimide, or polyamideimide to be mixed more uniformly with the fine particles. Furthermore, the fine particles can be uniformly distributed in the unsintered composite membrane. As a result, dense openings are provided on the surface of the filter A according to this embodiment that is finally obtained, and it is possible to efficiently form communicating holes that connect the front and back surfaces of the porous membrane so as to improve the air permeability of the polyimide-based resin porous membrane.

[0074] The dispersant is not particularly limited, and known dispersants can be used. Examples of the dispersant include anionic surfactants such as coconut fatty acid salts, castor sulfated oil salts, lauryl sulfate salts, polyoxyalkylene allyl phenyl ether sulfate salts, alkyl benzene sulfonic acids, alkyl benzene sulfonates, alkyl diphenyl ether disulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinate salts, isopropyl phosphate, polyoxyethylene alkyl ether phosphate salts, and polyoxyethylene allyl phenyl ether phosphate salts; cationic surfactants such as oleylamine acetate, lauryl pyridinium chloride, cetyl pyridinium chloride, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, and didecyl dimethyl ammonium chloride; and amphoteric surfactants such as coconut alkyl dimethyl amine oxide, fatty acid amidopropyl dimethyl amine oxide, alkyl polyaminoethyl glycine hydrochloride, amido betaine surfactants, alanine surfactants, and lauryliminodipropionic acid. antifungal agents; polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene laurylamine, polyoxyethylene oleylamine, polyoxyethylene polystyrylphenyl ether, polyoxyalkylene polystyrylphenyl ether and other polyoxyalkylene primary alkyl ether or polyoxyalkylene secondary alkyl ether nonionic surfactants, polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylenated castor oil, polyoxyethylenated hydrogenated castor oil, sorbitan laurate, polyoxyethylene sorbitan laurate, fatty acid diethanolamide and other polyoxyalkylene nonionic surfactants; fatty acid alkyl esters such as octyl stearate and trimethylolpropane tridecanoate; and polyether polyols such as polyoxyalkylene butyl ether, polyoxyalkylene oleyl ether and trimethylolpropane tris(polyoxyalkylene) ether.The above dispersants can be used alone or in combination of two or more.

[0075] The polyamic acid is not particularly limited, and may be any one obtained by polymerizing any tetracarboxylic acid dihydrate with a diamine.

[0076] The tetracarboxylic acid dihydrate is not particularly limited and known tetracarboxylic acid dihydrates can be used. Among them, aromatic tetracarboxylic acid dihydrates and aliphatic tetracarboxylic acid dihydrates are preferred.

[0077] Examples of aromatic tetracarboxylic acid dihydrates include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2,6,6-biphenyltetracarboxylic dianhydride. carboxylic acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride carboxylic acid dianhydride, bis(3,4-dicarboxyphenyl) ether dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride, 4,4-(p-phenylenedioxy)diphthalic acid dianhydride, 4,4-(m-phenylenedioxy)diphthalic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bisphthalic acid fluorene anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and the like.

[0078] Examples of the aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and 1,2,3,4-cyclohexane tetracarboxylic dianhydride.

[0079] Among these, aromatic tetracarboxylic dianhydrides are preferred from the viewpoint of the heat resistance of the resulting polyimide resin, and 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are particularly preferred from the viewpoints of price, availability, etc. The tetracarboxylic dianhydrides can be used alone or in combination of two or more.

[0080] The diamine is not particularly limited, and known diamines can be used. The diamine may be an aromatic diamine or an aliphatic diamine, but aromatic diamines are preferred from the viewpoint of the heat resistance of the resulting polyimide resin. The diamines can be used alone or in combination of two or more.

[0081] Examples of aromatic diamines include diamino compounds having one or about 2 to 10 phenyl groups bonded to one another. Specific examples of aromatic diamines include phenylenediamine or a derivative thereof, a diaminobiphenyl compound or a derivative thereof, a diaminodiphenyl compound or a derivative thereof, a diaminotriphenyl compound or a derivative thereof, a diaminonaphthalene or a derivative thereof, an aminophenylaminoindan or a derivative thereof, a diaminotetraphenyl compound or a derivative thereof, a diaminohexaphenyl compound or a derivative thereof, and a cardo-type fluorenediamine derivative.

[0082] The phenylenediamine is preferably m-phenylenediamine or p-phenylenediamine. Phenylenediamine derivatives include diamines having alkyl groups such as methyl groups and ethyl groups bonded thereto, such as 2,4-diaminotoluene and 2,4-triphenylenediamine.

[0083] Diaminobiphenyl compounds are compounds in which two aminophenyl groups are bonded together via the phenyl groups. Examples of diaminobiphenyl compounds include 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

[0084] A diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via another group. Examples of the other group include an ether bond, a sulfonyl bond, a thioether bond, an alkylene group or a derivative thereof, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, and a ureylene bond. The alkylene group preferably has about 1 to 6 carbon atoms, and the derivative group is an alkylene group in which one or more hydrogen atoms have been substituted with a halogen atom or the like.

[0085] Examples of diaminodiphenyl compounds include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2-bis(p-aminophenyl)propane, 2,2'-bis(p-aminophenyl)hexafluoropropane, 4-methyl-2,4-bis(p-aminophenyl)-1-pentene, 4-methyl-2,4-bis(p-aminophenyl) )-2-pentene, iminodianiline, 4-methyl-2,4-bis(p-aminophenyl)pentane, bis(p-aminophenyl)phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-diaminodiphenylamide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and the like.

[0086] Diaminotriphenyl compounds are compounds in which two aminophenyl groups and one phenylene group are bonded via other groups, such as those in diaminodiphenyl compounds. Examples of the diaminotriphenyl compound include 1,3-bis(m-aminophenoxy)benzene, 1,3-bis(p-aminophenoxy)benzene, and 1,4-bis(p-aminophenoxy)benzene.

[0087] Examples of diaminonaphthalene include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

[0088] Examples of aminophenylaminoindan include 5- or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindan.

[0089] Examples of diaminotetraphenyl compounds include 4,4'-bis(p-aminophenoxy)biphenyl, 2,2'-bis[p-(p'-aminophenoxy)phenyl]propane, 2,2'-bis[p-(p'-aminophenoxy)biphenyl]propane, and 2,2'-bis[p-(m-aminophenoxy)phenyl]benzophenone.

[0090] Examples of cardo-type fluorenediamine derivatives include 9,9-bisanilinefluorene.

[0091] The aliphatic diamine preferably has, for example, about 2 to 15 carbon atoms, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

[0092] The diamine may be a compound in which a hydrogen atom is substituted with at least one substituent selected from the group consisting of a halogen atom, a methyl group, a methoxy group, a cyano group, and a phenyl group.

[0093] Among the above, phenylenediamine, phenylenediamine derivatives, and diaminodiphenyl compounds are preferred as diamines, and among these, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4′-diaminodiphenyl ether are more preferred in terms of cost, availability, etc.

[0094] The method for producing the polyamic acid is not particularly limited, and any known method can be used, such as a method of reacting any tetracarboxylic dianhydride with a diamine in an organic solvent. The reaction between the tetracarboxylic dianhydride and the diamine is generally carried out in an organic solvent. The organic solvent used here is not particularly limited as long as it can dissolve the tetracarboxylic dianhydride and the diamine, respectively, and does not react with the tetracarboxylic dianhydride and the diamine. The organic solvent may be used alone or in combination of two or more.

[0095] Examples of organic solvents used in the reaction between tetracarboxylic dianhydride and diamine include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N',N'-tetramethylurea; lactone-based polar solvents such as β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, and ε-caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate, and ethyl cellosolve acetate; and phenolic solvents such as cresols.

[0096] Among these, it is preferable to use a nitrogen-containing polar solvent as the organic solvent in view of the solubility of the polyamic acid produced. From the viewpoint of film-forming properties, it is preferable to use a mixed solvent containing a lactone polar solvent. In this case, the content of the lactone polar solvent relative to the total organic solvent (100% by mass) is preferably 1 to 20% by mass, more preferably 5 to 15% by mass. The organic solvent used here is preferably one or more selected from the group consisting of nitrogen-containing polar solvents and lactone-based polar solvents, and more preferably a mixed solvent of a nitrogen-containing polar solvent and a lactone-based polar solvent. The amount of organic solvent used is not particularly limited, but it is preferable that the content of the produced polyamic acid in the reaction liquid after the reaction is about 5 to 50% by mass.

[0097] The amounts of the tetracarboxylic dianhydride and the diamine used are not particularly limited, but it is preferable to use 0.50 to 1.50 mol of the diamine per 1 mol of the tetracarboxylic dianhydride, more preferably 0.60 to 1.30 mol, and particularly preferably 0.70 to 1.20 mol.

[0098] In general, the reaction (polymerization) temperature is preferably from -10 to 120°C, more preferably from 5 to 30°C. The reaction (polymerization) time varies depending on the composition of the raw materials used, but is generally preferably 3 to 24 hours. The intrinsic viscosity of the polyamic acid solution is not particularly limited, but is preferably 1000 to 100000 cP (centipoise) (1 to 100 Pa·s), and more preferably 5000 to 70000 cP (5 to 70 Pa·s). The intrinsic viscosity of the polyamic acid solution can be measured at a temperature of 25°C using an E-type rotational viscometer.

[0099] The polyimide that can be used to manufacture the filter A according to this embodiment is not limited in structure or molecular weight, and any known polyimide can be used as long as it is soluble in the organic solvent used in the varnish. The polyimide may have a condensable substituent such as a carboxyl group on the side chain, or a substituent that promotes a crosslinking reaction or the like during baking.

[0100] To make the polyimide soluble in the organic solvent used in the varnish, it is effective to use a monomer that introduces a flexible, bent structure into the main chain. Examples of such monomers include aliphatic diamines such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, and 4,4'-diaminodicyclohexylmethane; aromatic diamines such as 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, and 4,4'-diaminobenzanilide; polyoxyethylenediamine, polyoxypropylenediamine, and polyoxybutylenediamine; polysiloxanediamine; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, and 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride.

[0101] It is also effective to use a monomer having a substituent that improves the solubility in such organic solvents, such as fluorinated diamines such as 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2-trifluoromethyl-1,4-phenylenediamine. Furthermore, in addition to the monomer having such a substituent, the monomers exemplified in the description of the polyamic acid above can also be used in combination, as long as the solubility is not impaired.

[0102] The method for producing the polyimide is not particularly limited, and examples thereof include known methods such as a method in which polyamic acid is chemically imidized or thermally imidized and then dissolved in an organic solvent.

[0103] Examples of polyimides include aliphatic polyimides (all aliphatic polyimides) and aromatic polyimides, and among these, aromatic polyimides are preferred. The aromatic polyimide may be one obtained by subjecting a polyamic acid having a unit represented by the following general formula (5) to a thermal or chemical ring-closing reaction, or one obtained by dissolving a polyimide having a unit represented by the following general formula (6) in a solvent. In the formula, R Ar is an aryl group, R' Ar represents an arylene group.

[0104] [ka]

[0105] In the formula, R Ar is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Among these, R Ar is preferably an aromatic hydrocarbon ring, more preferably benzene or naphthalene, and particularly preferably benzene. In the formula, R' Ar is R Ar Examples of such groups include those in which two hydrogen atoms have been removed from the aromatic ring in the above formula. Ar is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring, more preferably a group in which two hydrogen atoms have been removed from benzene or naphthalene, and particularly preferably a phenylene group in which two hydrogen atoms have been removed from benzene. R Ar the aryl group in R' Ar Each of the arylene groups in the formula (I) may have a substituent.

[0106] The polyamideimide is not limited in structure or molecular weight, and any known polyamideimide can be used as long as it is soluble in the organic solvent used in the varnish. The polyamideimide may have a condensable substituent such as a carboxyl group on the side chain, or a substituent that promotes a crosslinking reaction or the like during baking.

[0107] As the polyamideimide, those obtained by reacting any trimellitic anhydride with a diisocyanate, and those obtained by imidizing a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride with a diamine can be used.

[0108] Examples of the above-mentioned optional reactive derivatives of trimellitic anhydride include trimellitic anhydride halides such as trimellitic anhydride chloride, and trimellitic anhydride esters.

[0109] Examples of the optional diisocyanate include metaphenylene diisocyanate, p-phenylene diisocyanate, o-tolidine diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4'-oxybis(phenylisocyanate), 4,4'-diisocyanatodiphenylmethane, bis[4-(4-isocyanatophenoxy)phenyl]sulfone, 2,2'-bis[4-(4-isocyanatophenoxy)phenyl]propane, 2,4 -tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 3,3'-diethyldiphenyl-4,4'-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, naphthalene diisocyanate, and the like.

[0110] Examples of the optional diamine include the same diamines as those exemplified in the description of the polyamic acid.

[0111] The organic solvent that can be used to prepare the varnish is not particularly limited as long as it can dissolve the polyamic acid and / or polyimide resin and does not dissolve the fine particles, and examples thereof include the same organic solvents as those used in the reaction between the tetracarboxylic dianhydride and the diamine. The organic solvents can be used alone or in combination of two or more.

[0112] The content of the organic solvent in the varnish is preferably 50 to 95 mass %, more preferably 60 to 85 mass %, based on the total mass of the varnish, and the solid content of the varnish is preferably 5 to 50 mass %, more preferably 15 to 40 mass %.

[0113] Furthermore, when forming a two-layer unsintered composite film, the first varnish is first applied directly onto a substrate such as a glass substrate, and dried under normal pressure or vacuum at 0 to 120°C (preferably 0 to 90°C), more preferably at normal pressure and 10 to 100°C (even more preferably 10 to 90°C) to form a first unsintered composite film having a thickness of 1 to 5 μm. Next, the second varnish is applied onto the first unsintered composite film, and similarly dried at 0 to 80°C (preferably 0 to 50°C), more preferably at 10 to 80°C (even more preferably 10 to 30°C) under normal pressure, to form a second unsintered composite film with a thickness of 5 to 50 μm, thereby forming a two-layer unsintered composite film.

[0114] After the formation of the green composite film, the green composite film is subjected to a heat treatment (firing) to form a composite film (polyimide resin-particle composite film) made of the polyimide resin and the particles. When the varnish contains polyamic acid, it is preferable to complete the imidization by baking the unbaked composite film in this step.

[0115] The temperature for the heat treatment (baking temperature) varies depending on the structure of the polyamic acid, polyimide or polyamideimide contained in the unbaked composite film and the presence or absence of a condensing agent, but is preferably 120 to 400°C, more preferably 150 to 375°C.

[0116] The calcination process does not necessarily have to be clearly separated from the drying process in the previous step; a stepwise drying-thermal imidization method can also be used. Specifically, when calcining at 375°C, a method can be used in which the temperature is raised from room temperature to 375°C over 3 hours, and then held at 375°C for 20 minutes. Another method can be used in which the temperature is raised from room temperature to 375°C in 50°C increments (holding for 20 minutes at each increment), and finally held at 375°C for 20 minutes. A method can also be used in which the edges of the unsintered composite film are fixed to a stainless steel mold or similar to prevent deformation.

[0117] The thickness of the polyimide resin-fine particle composite film after heat treatment (baking) is, for example, preferably 1 μm or more, more preferably 5 to 500 μm, and even more preferably 8 to 100 μm. The thickness of the polyimide resin-fine particle composite film is determined by measuring the thickness at multiple locations using a micrometer and averaging these values.

[0118] This step is optional, and may not be performed, particularly when polyimide or polyamideimide is used in the varnish.

[0119] After firing the unfired composite film, the particles are removed from the polyimide resin-particle composite film to produce a porous polyimide resin film. For example, when silica is used as the fine particles, the silica is dissolved and removed by contacting the polyimide resin-particle composite film with low-concentration hydrogen fluoride (HF) water, resulting in a porous film. Also, when the fine particles are resin fine particles, the resin fine particles are decomposed and removed by heating the film to a temperature above the thermal decomposition temperature of the resin fine particles but below the thermal decomposition temperature of the polyimide resin, resulting in a porous film.

[0120] The etching step can be carried out by a chemical etching method, a physical removal method, or a combination of these methods.

[0121] As the chemical etching method, a conventionally known method can be used. The chemical etching method is not particularly limited, and examples thereof include treatment with an etching solution such as an inorganic alkaline solution or an organic alkaline solution, among which treatment with an inorganic alkaline solution is preferred. Examples of inorganic alkaline solutions include hydrazine solutions containing hydrazine hydrate and ethylenediamine; solutions of alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium silicate, and sodium metasilicate; ammonia solutions; and etching solutions containing alkali hydroxides, hydrazine, and 1,3-dimethyl-2-imidazolidinone as main components. Examples of organic alkaline solutions include alkaline etching solutions such as primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and cyclic amines such as pyrrole and piperidine. The alkali concentration in the etching solution is, for example, 0.01 to 20% by mass.

[0122] The solvent for each of the above etching solutions can be selected appropriately from pure water and alcohols, and those containing an appropriate amount of surfactant can also be used.

[0123] The physical removal method may be, for example, a dry etching method using plasma (oxygen, argon, etc.), corona discharge, or the like.

[0124] The above-mentioned chemical etching method or physical removal method can be applied before or after the particle removal step already described. Among these, it is preferable to apply the process after the fine particle removal step, since this makes it easier to form continuous pores inside the porous polyimide resin membrane and improves the removal of foreign matter.

[0125] When chemical etching is used in the etching step, a step of washing the porous polyimide resin membrane may be carried out after this step in order to remove excess etching solution. The cleaning after chemical etching may be carried out by washing with water alone, but it is preferable to combine acid washing and washing with water.

[0126] After the etching step, the porous polyimide resin membrane may be subjected to a heat treatment (re-baking) to improve the wettability of the surface of the porous polyimide resin membrane to organic solvents and to remove residual organic matter. The heating conditions are the same as those for baking the unbaked composite membrane.

[0127] The pore size of the filter A according to this embodiment is not particularly limited, but is generally preferably 0.1 to 100 nm, more preferably 0.1 to 50 nm, and even more preferably 0.1 to 20 nm. In this specification, the pore size refers to the pore size determined by the bubble point of isopropanol (IPA) or HFE-7200 ("Novec 7200", manufactured by 3M, hydrofluoroether, C4F9OC2H5).

[0128] <Filter BD> Filter BD has a different pore size from filter A (having a smaller pore size than filter A) and is disposed in series with filter A on the downstream side of filter A in the flow passage. Note that "downstream" refers to the outlet side of the flow passage. In this specification, "different filters" means that they differ in at least one element selected from the group consisting of pore size, material, and pore structure. In particular, in terms of obtaining a filtration device that has better effects of the present invention, it is preferable that filter A and filter BD differ in at least pore size, and more preferably in pore size and material.

[0129] The pore size of filter BD according to this embodiment is not particularly limited as long as it is smaller than the pore size of filter A, and filters with pore sizes typically used for filtering liquids to be purified can be used. Among these, the pore size of the filter is preferably 200 nm or less, more preferably 20 nm or less, even more preferably 10 nm or less, particularly preferably 5 nm or less, and most preferably 3 nm or less. While there is no particular lower limit, a pore size of 1 nm or more is generally preferred from the viewpoint of productivity. The inventors have found that when a liquid to be purified is filtered using filter A, flowing the liquid to be purified through filter A can generate fine particles originating from the material of filter A and contaminate the liquid to be purified. The filtration device according to this embodiment has filter BD downstream of filter A in the flow path, so that the fine particles originating from filter A can be filtered out from the liquid to be purified, making it easier to obtain a chemical solution with better defect suppression performance.

[0130] 1 has one filter BD, the filtration device according to this embodiment may have multiple filters BD. In this case, the relationship between the pore sizes of the multiple filters BD is not particularly limited, but it is preferable that the pore size of the filter BD located furthest downstream in the flow path be smallest, since this makes it easier to obtain a chemical solution with better defect suppression performance.

[0131] The material of filter BD is not particularly limited, and may be the same as or different from filter A. In particular, it is preferable that the material be different from that of filter A, since this will result in a filtration device that has better effects of the present invention. When the filter BD is a resin, it may contain material components such as polyamides such as 6-nylon and 6,6-nylon; polyolefins such as polyethylene and polypropylene; polystyrene; polyimide; polyamideimide; poly(meth)acrylate; polyfluorocarbons such as polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride; polyvinyl alcohol; polyester; cellulose; cellulose acetate, etc. Among these, in terms of having better solvent resistance and providing a chemical solution with better defect suppression performance, it is preferable to contain at least one material selected from the group consisting of nylon (especially 6,6-nylon), polyolefin (especially polyethylene), poly(meth)acrylate, and polyfluorocarbon (especially polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA) are preferred), and it is more preferable to contain at least one resin selected from the group consisting of polyethylene, nylon, and polytetrafluoroethylene. These polymers can be used alone or in combination of two or more. In addition to resin, materials such as diatomaceous earth and glass may also be used.

[0132] The filter may also be surface-treated. The surface treatment method is not particularly limited, and known methods can be used. Examples of surface treatment methods include chemical modification treatment, plasma treatment, hydrophobic treatment, coating, gas treatment, and sintering.

[0133] Plasma treatment is preferred because it hydrophilizes the filter surface. The water contact angle on the surface of the filter material hydrophilized by plasma treatment is not particularly limited, but the static contact angle at 25°C measured with a contact angle meter is preferably 60° or less, more preferably 50° or less, and even more preferably 30° or less.

[0134] As the chemical modification treatment, a method of introducing ion exchange groups into the substrate is preferred. That is, the filter is preferably one in which the above-mentioned materials are used as a substrate and ion exchange groups are introduced into the substrate. Typically, a filter is preferred that includes a layer containing a substrate having ion exchange groups on the surface of the substrate. The surface-modified substrate is not particularly limited, and in terms of ease of production, one in which ion exchange groups are introduced into the above-mentioned polymer is preferred.

[0135] Examples of the ion exchange group include a sulfonic acid group, a carboxyl group, and a phosphate group as a cation exchange group, and a quaternary ammonium group as an anion exchange group. The method for introducing the ion exchange group into the polymer is not particularly limited, but includes a method in which a compound having an ion exchange group and a polymerizable group is reacted with the polymer to typically perform grafting.

[0136] The method for introducing ion exchange groups is not particularly limited, but may involve irradiating fibers of the above resins with ionizing radiation (such as α-rays, β-rays, γ-rays, X-rays, and electron beams) to generate active moieties (radicals) in the resin. The irradiated resin is then immersed in a monomer-containing solution to graft polymerize the monomer onto the substrate. As a result, the monomer is bonded to the polyolefin fiber as a graft-polymerized side chain. The resin having this generated polymer as a side chain is then contact-reacted with a compound having an anion exchange group or a cation exchange group, thereby introducing ion exchange groups into the graft-polymerized side chain polymer, yielding the final product.

[0137] The filter may also be constructed by combining a woven or nonwoven fabric on which ion exchange groups have been formed by radiation graft polymerization with a conventional filtering material such as glass wool, woven or nonwoven fabric.

[0138] In particular, in order to obtain a filtration device having better effects of the present invention, it is preferable that the filter BD contains at least one material component selected from the group consisting of polyolefin, polyamide, polyfluorocarbon, polystyrene, and polyethersulfone, and it is more preferable that the filter BD is made of at least one material component selected from the group consisting of polyolefin, polyamide, polyfluorocarbon, polystyrene, and polyethersulfone. Examples of polyolefins include polyethylene and polypropylene, with ultra-high molecular weight polyethylene being preferred. Examples of polyamides include 6-nylon and 6,6-nylon. Examples of polyfluorocarbons include polytetrafluoroethylene, perfluoroalkoxyalkane, perfluoroethylenepropene copolymer, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, and polyvinyl fluoride, with at least one selected from the group consisting of polyethylene and nylon being preferred, and in another embodiment, polytetrafluoroethylene being preferred.

[0139] The filter BD preferably contains, as a material component, a second resin having a hydrophilic group. The hydrophilic group is not particularly limited, but examples thereof include a hydroxyl group, an ether group, an oxyalkylene group, a carboxylic acid group, an ester group, a carbonate ester group, a thiol group, a thioether group, a phosphoric acid group, a phosphoric acid ester group, an amide group, an imide group, and combinations thereof, with a hydroxyl group, an ether group, an oxyalkylene group, an ester group, a carbonate ester group, a thiol group, and a thioether group being preferred. The second resin is not particularly limited, but examples thereof include polyolefin, polyamide, polyimide, polyether, novolac, polystyrene, cycloolefin polymer, and polylactic acid, with polyolefin, polyimide, polystyrene, and cycloolefin polymer being preferred.

[0140] The pore structure of the filter BD is not particularly limited and may be appropriately selected depending on the components of the liquid to be purified. In this specification, the pore structure of the filter BD refers to the pore size distribution, the positional distribution of the pores in the filter, the pore shape, etc., and can typically be controlled by the filter manufacturing method. For example, porous membranes can be obtained by sintering powders of resins or the like, and fibrous membranes can be obtained by methods such as electrospinning, electroblowing, and meltblowing, each of which has a different pore structure.

[0141] "Porous membrane" refers to a membrane that retains components of a liquid to be purified, such as gels, particles, colloids, cells, and poly-oligomers, while allowing components substantially smaller than the pores to pass through the pores. The retention of components in a liquid to be purified by a porous membrane can depend on operating conditions, such as face velocity, the use of surfactants, pH, and combinations thereof, and can also depend on the pore size and structure of the porous membrane and the size and structure of the particles to be removed (e.g., hard particles or gels).

[0142] UPE (ultra-high molecular weight polyethylene) filters are typically sieving membranes, meaning membranes that capture particles primarily through sieving retention mechanisms or membranes optimized for capturing particles through sieving retention mechanisms. Typical examples of sieving membranes include, but are not limited to, polytetrafluoroethylene (PTFE) membranes and UPE membranes. The "sieve retention mechanism" refers to the fact that the target particles are retained because they are larger than the pore size of the porous membrane. The sieve retention can be improved by forming a filter cake (an agglomeration of the target particles on the membrane surface). The filter cake effectively performs the function of a secondary filter.

[0143] The pore structure of the porous membrane (for example, a porous membrane containing UPE, PTFE, etc.) is not particularly limited, and examples of the pore shape include lace-like, string-like, and node-like. The pore size distribution in the porous membrane and the distribution of its positions within the membrane are not particularly limited. The size distribution may be narrower and the distribution positions within the membrane may be symmetrical. Alternatively, the size distribution may be wider and the distribution positions within the membrane may be asymmetrical (the above membrane is also referred to as an "asymmetric porous membrane"). In an asymmetric porous membrane, the pore size varies within the membrane, and typically, the pore size increases from one surface of the membrane to the other. In this case, the surface with more pores with larger pore sizes is referred to as the "open side," and the surface with more pores with smaller pore sizes is also referred to as the "tight side." Asymmetric porous membranes include, for example, membranes in which the size of the pores is smallest at a certain position within the thickness of the membrane (also called "hourglass shape").

[0144] Using an asymmetric porous membrane with larger pore size on the primary side (upstream side of the flow passage), in other words, the primary side being open, can create a pre-filtration effect.

[0145] The porous membrane may include a thermoplastic polymer such as PESU (polyethersulfone), PFA (perfluoroalkoxyalkane, a copolymer of tetrafluoroethylene and perfluoroalkoxyalkane), polyamide, and polyolefin, or may include polytetrafluoroethylene, etc. Among these, it is preferable that the porous film contains ultra-high molecular weight polyethylene as a material component. Ultra-high molecular weight polyethylene means a thermoplastic polyethylene having an extremely long chain, and preferably has a molecular weight of one million or more, typically 2 to 6 million.

[0146] For example, when the liquid to be purified contains particles containing organic compounds as impurities, these particles are often negatively charged, and polyamide filters function as non-sieving membranes to remove such particles. Typical non-sieving membranes include, but are not limited to, nylon membranes such as nylon-6 membranes and nylon-6,6 membranes. It is noted that "non-sieving" retention mechanisms, as used herein, refer to retention that occurs through mechanisms such as obstruction, diffusion, and adsorption that are not related to the pressure drop or pore size of the filter.

[0147] Non-sieving retention includes retention mechanisms such as obstruction, diffusion, and adsorption that remove target particles in the purified liquid, regardless of the filter's pressure drop or pore size. Particle adsorption to the filter surface can be mediated, for example, by intermolecular van der Waals and electrostatic forces. Obstruction occurs when particles moving through a non-sieving membrane layer with a tortuous path cannot change direction quickly enough to avoid contact with the non-sieving membrane. Diffusion-based particle transport results primarily from the random or Brownian motion of small particles, which creates a certain probability of particle collision with the filter material. Non-sieving retention mechanisms can be active when there is no repulsive force between the particles and the filter.

[0148] The material of the fiber membrane is not particularly limited as long as it is a polymer capable of forming a fiber membrane. Examples of polymers include polyamides. Examples of polyamides include nylon 6 and nylon 6,6. The polymer forming the fiber membrane may be poly(ether sulfone). When the fiber membrane is on the primary side of the porous membrane, it is preferable that the surface energy of the fiber membrane is higher than that of the polymer that is the material of the porous membrane on the secondary side (downstream of the flow channel). An example of such a combination is when the fiber membrane is made of nylon and the porous membrane is made of polyethylene (UPE).

[0149] The method for producing the fiber membrane is not particularly limited, and known methods can be used, such as electrospinning, electroblowing, and meltblowing.

[0150] Second Embodiment FIG. 2 is a schematic diagram showing a filtering device according to a second embodiment of the present invention. The filtration device 200 is a filtration device in which a filter 103, which is a filter A, and a filter 201 different from the filter 103 are arranged in series via a pipe 202 between an inflow section 101 and an outflow section 102. The inlet section 101, filter 201, piping 202, filter 103, and outlet section 102 are configured so that the liquid to be purified can flow through each of them, and the above components are connected to form a flow path S2 (a path through which the liquid to be purified flows).

[0151] In the filtration device 200, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0152] <Filter BU> Filter BU is a filter that has at least a different pore size from filter A (having a larger pore size than filter A) and is disposed in series with filter A on the upstream side of filter A in the flow passage. In order to obtain a filtration device that has better effects of the present invention, it is preferable that filter A and filter BU have different pore sizes and materials. Furthermore, "upstream side" refers to the inlet side of the flow passage.

[0153] The pore size of filter BU is not particularly limited as long as it is larger than that of filter A, and a filter having a pore size normally used for filtering a liquid to be purified can be used. In particular, the pore size of the filter is preferably 200 nm or less, and more preferably 20 nm or more. According to the studies of the present inventors, it has been found that when a filtration device is used in which a filter BU having a pore size of 20 nm or more is arranged on the flow path S2 upstream of the filter A, the filter A is less likely to clog and the life of the filter A can be extended. As a result, a filtration device is obtained that can stably provide a chemical solution with better defect suppression performance.

[0154] 2 has one filter BU, the filtration device according to this embodiment may have multiple filters BU. In this case, the relationship between the pore sizes of the multiple filters BU is not particularly limited, but it is preferable that the filter BU located most upstream in the flow path has the largest pore size, as this makes it easier to obtain a chemical solution with better defect suppression performance. This can extend the life of the filters (including filter A) located downstream of the most upstream filter BU, resulting in a filtration device that can stably provide a chemical solution with better defect suppression performance.

[0155] The filter BU is not particularly limited, but preferably contains a material component capable of removing ions, in order to obtain a filtration device that has better effects of the present invention. In other words, the filter BU is preferably an ion removal filter, and preferably contains, for example, a resin having ion exchange groups, and in order to obtain a filtration device that has better effects of the present invention, the ion exchange groups are preferably at least one type selected from the group consisting of acid groups (cation exchange groups) and basic groups (anion exchange groups). Examples of the ion exchange group include a cation exchange group (acid group) such as a sulfonic acid group, a carboxy group, and a phosphate group, and an anion exchange group (basic group) such as a quaternary ammonium group. There are no particular limitations on the method for introducing the ion exchange group into the polymer, but examples include a method in which a compound having an ion exchange group and a polymerizable group is reacted with the polymer, typically for grafting, and a method in which polymers having different functional groups are mixed. The filter BU more preferably contains a material component in which an ion exchange group is introduced into a base material such as polyfluorocarbon or polyolefin.

[0156] (Modification of the filtration device according to the second embodiment) 3 is a schematic diagram of a filtration device showing a modified example of the filtration device according to the second embodiment of the present invention. Filtration device 300 has filter 103, which is filter A, filter 201, which is filter BU, and filter 104, which is filter BD, between inlet section 101 and outlet section 102, and filter 201, filter 103, and filter 104 are arranged in series via pipes 301 and 302.

[0157] In the filtration device 300, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0158] Inlet portion 101, filter 201, pipe 301, filter 103, pipe 302, and filter 104 are configured so that the liquid to be purified can flow through them, and the above components are connected to form flow path S3 (a path through which the liquid to be purified flows). The configuration of the pipes and each filter has already been described. The filtration device 300 has filter BU upstream of filter A in the flow path, which gives filter A a longer life, and has filter BD downstream of filter A in the flow path, which can efficiently remove fine particles that are mixed into the purified liquid due to filter A, resulting in a chemical liquid with even better defect suppression performance.

[0159] Third Embodiment FIG. 4 is a schematic diagram showing a filtering device according to a third embodiment of the present invention. The filtration device 400 is a filtration device that further includes a tank 401 that is disposed in series with the filter 103 (filter A) on the flow path S4, between the inflow section 101 and the outflow section 102, on the upstream side of the filter A. The tank 401, the filter 103 (filter A), and the filter 104 (filter BD) are disposed in series via a pipe 402 and a pipe 105. The tank 401, together with the above-mentioned filters and pipes, etc., constitutes the flow path S4.

[0160] In the filtration device 400, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0161] The filtration device according to this embodiment has a tank upstream of filter 103, so that the liquid to be purified to be passed through filter 103 can be retained and homogenized, resulting in a chemical solution with even better defect suppression performance. In particular, when performing circulating filtration, which will be described later, tank 401 can be used to receive the returned liquid to be purified when returning the liquid to be purified from downstream of filter 103 (filter A) to upstream of filter 103 through flow path S4. In this way, the returned liquid to be purified can be retained and homogenized before being passed through filter 103 again, resulting in a chemical solution with even better defect suppression performance. The material of the tank 401 is not particularly limited, but the same material as the material of the housing already described can be used, and it is preferable that at least a portion of its liquid-contacting portion (preferably 90% or more of the surface area of ​​the liquid-contacting portion, more preferably 99% or more) be made of a corrosion-resistant material described below.

[0162] (Modification of the filtration device according to the third embodiment) FIG. 5 is a schematic diagram showing a modified example of the filtering device according to the third embodiment of the present invention. The filtration device 500 is a filtration device further including a tank 401 disposed in series with the filter 103 (filter A) on the flow path S5, between the inflow section 101 and the outflow section 102, downstream of the filter A. The filter 103 (filter A), the tank 401, and the filter 104 (filter BD) are disposed in series via pipes 501 and 502. The tank 401, together with the above-mentioned filters and pipes, etc., constitutes the flow path S5.

[0163] In the filtration device 500, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0164] The filtration device according to this embodiment has a tank downstream of filter A, allowing the liquid to be purified that has been filtered by filter A to remain. In particular, when performing circulating filtration, which will be described later, tank 401 can be used to retain the returned liquid to be purified when returning the liquid to be purified from the downstream side of filter 103 (filter A) to the upstream side of filter 103 along flow path S5. In this way, the returned liquid to be purified can be retained and homogenized before being passed through filter 103 again, thereby obtaining a chemical solution with even better defect suppression performance.

[0165] In the filtration device 500 of this embodiment, the tank 401 is arranged upstream of the filter 104 (filter BD) on the flow path S5, but in the filtration device of this embodiment, the tank 401 may also be arranged downstream of the filter 104 on the flow path S5. As already explained, when filter BD is used, even if particles are mixed into the liquid to be purified due to passing the liquid through filter A, the particles can be efficiently removed.

[0166] As already explained, tank 401 can be used to retain the purified liquid to be returned during circulating filtration. In other words, it can be used as the starting point of circulating filtration, and in that case, the filter upstream of tank 401 (filter 103 in filtration device 500) or the downstream side on flow path S5 is often the target of circulating filtration. Note that the starting point of circulating filtration includes both the case where the tank constitutes the return flow path and the case where the piping downstream of the tank constitutes the return flow path.

[0167] In filtration device 500, tank 401 is disposed upstream of filter 104 (filter BD). When tank 401 is disposed upstream of filter 104 (filter BD) and the portion of flow path S5 up to tank 401 is repeated during circulating filtration, a flow can be adopted in which the purified liquid is sufficiently filtered by filter A, and then fine particles originating from filter A are finally removed by filter 104, thereby extending the life of filter BD and improving the efficiency of chemical liquid production.

[0168] The filtration device according to this embodiment may be configured in such a manner that filter BU and filter A are arranged in series in this order (for example, the second embodiment), or in such a manner that filter BU, filter A, and filter BD are arranged in series in this order (for example, a modified example of the second embodiment), and further have tank 401 upstream of filter A.

[0169] Fourth Embodiment FIG. 6 is a schematic diagram showing a filtering device according to a fourth embodiment of the present invention. The filtration device 600 is a filtration device in which a filter 601, which is filter C, a tank 401, a filter 103, which is filter A, and a filter 104, which is filter BD, are connected in series between an inlet section 101 and an outlet section 102 via pipes 602, 402, and 105. In the filtration device 600, the inflow section 101, the filter 601, the pipe 602, the tank 401, the pipe 402, the filter 103, the pipe 105, the filter 104, and the outflow section 102 form a flow path S6.

[0170] In the filtration device 600, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0171] Filter 601 (filter C) is a filter with a pore size of 20 nm or more, and is disposed upstream of tank 401 in flow path S6. In the filtration device according to this embodiment, a filter with a predetermined pore size is disposed upstream of tank 401 in flow path S6. Therefore, impurities contained in the liquid to be purified that flows into the filtration device from inlet 101 can be removed in advance using filter 601. As a result, the amount of impurities that enters the flow path from pipe 602 onwards can be reduced, thereby extending the lifespan of filters A and BD in the subsequent stages. As a result, the filtration device described above can stably produce chemical solutions with superior defect suppression performance.

[0172] The form of filter C is not particularly limited, and it may be the same filter as filter A already described, or a different filter (filter B). Of these, filter B is preferred because it makes it easier to obtain a chemical solution with better defect suppression performance. Of these, the material and pore structure described as the material and pore structure of filter BD are preferred. The pore diameter may be 20 nm or more, preferably 50 nm or more, and although there is no particular upper limit, it is generally preferred that it be 250 nm or less. The filtration device according to this embodiment may be configured such that filter A and filter BD are arranged in series in this order on the flow path (for example, the second embodiment), or may be configured such that filter BU, filter A, and filter BD are arranged in series in this order on the flow path (for example, a modified example of the second embodiment), and further have a tank downstream of filter A and filter C upstream of the tank.

[0173] Fifth Embodiment 7 is a schematic diagram of a filtration device according to a fifth embodiment of the present invention. Filtration device 700 has inflow section 101, outflow section 102, filter 103 which is filter A, and filter 104 which is filter BD, with filters 103 and 104 arranged in series between inflow section 101 and outflow section 102, and a flow path S7 extending from inflow section 101 to outflow section 102 being formed. In the filtering device 700, the inflow section 101, the filter 103, the pipe 105, the filter 104, and the outflow section 102 form a flow passage S7.

[0174] In the filtration device 700, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0175] The filtration device 700 is formed with a return flow path R1 that can return the purified liquid from the downstream side of the filter 103 (and filter 104) in the flow path S7 to the upstream side of the filter 103 in the flow path S7. Specifically, the filtration device 700 has a return piping 701, and this piping 701 forms the return flow path R1. One end of the piping 701 is connected to the flow path S7 downstream of the filter 103 (and filter 104), and the other end is connected to the flow path S7 upstream of the filter 103. Note that a pump, a damper, a valve, and the like (not shown) may be arranged on the return flow path R1. In particular, it is preferable to arrange valves at the connection parts J1 and J2 shown in FIG. 7 to control the purified liquid not to flow unintentionally through the return flow path.

[0176] The purified liquid that has flowed through return flow path R1 and returned to the upstream side (in flow path S7) of filter 103 is filtered by filters 103 and 104 while flowing through flow path S7 again. This is called circulating filtration, and the filtration device 700 can perform circulating filtration, which makes it easier to obtain a chemical liquid with better defect suppression performance.

[0177] In Figure 7, piping 701 is arranged on the flow path S7 so that the purified liquid can be returned from the downstream side of filter 104 (filter BD) to the upstream side of filter A, but the filtration device of this embodiment is only required to be configured so that the purified liquid can be returned from the downstream side of filter A to the upstream side of filter A on the flow path, and a return flow path may be formed by piping connecting piping 105 and inlet section 101. Furthermore, when a filter BU is arranged upstream of filter A on the flow path, a return flow path may be formed that can return the purified liquid from the downstream side of filter A to the upstream side of filter BU. In addition, in FIG. 7, the return flow passage R1 is formed only by a pipe, but it may be formed by one or more tanks and pipes as already explained.

[0178] (Modification of the filtration device according to the fifth embodiment) FIG. 8 is a schematic diagram showing a modification of the filtering device according to the fifth embodiment of the present invention. Filtration device 800 has inlet section 101, tanks 401(a), 401(b), outlet section 102, filter 103 which is filter A, and filter 104 which is filter BD, and tank 401(a), filter 103, filter 104, and 401(b) are arranged in series between inlet section 101 and outlet section 102, and inlet section 101, tank 401(a), piping 802, filter 103, piping 803, filter 104, piping 804, tank 401(b), and outlet section 102 form a flow path S8.

[0179] In the filtration device 800, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0180] Filtration device 800 is formed with a return flow path R2 that can return the purified liquid from the downstream side of tank 401(b), which is arranged on flow path S8 downstream of filter 104, to the upstream side of tank 401(a), which is arranged on flow path S8 upstream of filter 103. One end of piping 801 is connected to flow path S8 downstream of tank 401(b), and the other end is connected to flow path S8 upstream of tank 401(a). Note that a pump, a damper, a valve, etc. (not shown) may be arranged in return flow path R2.

[0181] In the filtration device according to this embodiment, the starting point of the return flow path R2 is located downstream of tank 401(b) on the flow path, and the end point is located upstream of tank 401(a) on the flow path. This allows the purified liquid to be retained before being returned during circulating filtration, and after being returned, the purified liquid can be retained before being circulated again, resulting in a chemical solution with superior defect suppression performance. The filtration device according to this embodiment may be configured such that tank 401(b) and piping 801 are directly connected, or such that tank 401(a) and piping 801 are directly connected, or such that both are provided. The starting point of the return flow path R2 may be located upstream of the tank 401(b) and downstream of the filter 104. The ending point of the return flow path R2 may be located downstream of the tank 401(a) and upstream of the filter 103.

[0182] Sixth Embodiment 9 is a schematic diagram of a filtration device according to a sixth embodiment of the present invention. The filtration device 900 has an inlet section 101, an outlet section 102, a filter 103 which is filter A, and a filter 104 which is filter BD, with filters 103 and 104 arranged in series between the inlet section 101 and the outlet section 102, and a flow path S9 extending from the inlet section 101 to the outlet section 102. In the filtering device 900, the inflow section 101, the filter 103, the pipe 105, the filter 104, and the outflow section 102 form a flow passage S9.

[0183] In the filtration device 900, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0184] The filtration device 900 is formed with a return flow path R3 that can return the purified liquid from the downstream side of the filter 104 on the flow path S9 to the downstream side of the filter 103 and upstream side of the filter 104 on the flow path S9. One end of a pipe 901 is connected to the flow path S9 downstream of the filter 104, and the other end is connected to the flow path S9 upstream of the filter 104 and downstream of the filter 103. Specifically, the filtration device 900 has the return flow path 901, and this pipe 901 forms the return flow path R3. Note that a pump, a damper, a valve, and the like (not shown) may be arranged on the return flow path R3.

[0185] The purified liquid that flows through return flow path R3 and is returned to the downstream side of filter 103 and upstream side of filter 104 is filtered by filter 104 while flowing through flow path S9 again. The filtration device 900 can perform circulating filtration, and as a result, a chemical liquid with better defect suppression performance is likely to be obtained.

[0186] In Figure 9, piping 901 is arranged so that the purified liquid can be returned from the downstream side of filter 104 (filter BD) on the flow path S9 to the downstream side of filter A on the flow path S9 and upstream side of filter BD, but the filtration device of this embodiment only needs to be configured so that the purified liquid can be returned from the downstream side of filter B on the flow path to the downstream side of filter A and upstream side of filter B. That is, a return flow path for returning the purified liquid from the downstream side of the filter 104 to the upstream side of the filter 103 may be formed in the flow path S9.

[0187] (Modification of the filtration device according to the sixth embodiment) 10 is a schematic diagram showing a modification of the filtration device according to the present embodiment. The filtration device 1000 has an inflow section 101, an outflow section 102, a filter 103 which is filter A, a filter 104-1 (reference filter) which is filter BD, and a filter 104-2, and the filters 103, 104-1, and 104-2 are arranged in series between the inflow section 101 and the outflow section 102, and has a flow path S10 which extends from the inflow section 101 to the outflow section 102. In the filtration device 1000, the inflow section 101, the filter 103, the pipe 105, the filter 104-1, the pipe 1001, the filter 104-2, and the outflow section 102 form a flow path S10.

[0188] In the filtration device 1000, the filters and the configuration of the piping are the same as those of the filtration device according to the first embodiment already described, and the following description will be limited to only the parts that are different from the first embodiment. Therefore, matters that are not described below are the same as those of the filtration device according to the first embodiment.

[0189] The filtration device 1000 has a return flow path R4 formed on the flow path S10 that can return the purified liquid from downstream of filter 104-1 (reference filter) to downstream of filter 103 and upstream of filter 104-1 (reference filter) on the flow path S10. One end of a pipe 1002 is connected to the flow path S10 upstream of filter 104-2 and downstream of filter 104-1, and the other end is connected to the flow path S10 downstream of filter 103 and upstream of filter 104-1. Specifically, the filtration device 1000 has a return pipe 1002, and this pipe 1002 forms the return flow path R4. Note that a pump, a damper, a valve, and the like (not shown) may be arranged in the return flow path R3.

[0190] The purified liquid returned by return flow path R4 to the downstream side of filter 103 on flow path S10 and upstream side of filter 104-1 is filtered by filter 104-1 while flowing through flow path S10 again. The filtration device 1000 can perform circulating filtration, and as a result, it is easy to obtain a chemical liquid with better defect suppression performance.

[0191] In the filtration device of Figure 10, a return flow path R4 is formed on the flow path S10 downstream of filter 104-1 (reference filter), i.e., from the upstream side of filter 104-2 to the upstream side of filter 104-1, but the filtration device of this embodiment is not limited to the above and may be a filtration device in which a return flow path is formed that can return the purified liquid from the downstream side of filter 104-2 to the upstream side of filter 104-2, a filtration device in which a return flow path is formed that can return the purified liquid from the downstream side of filter 104-2 to the downstream side of filter A and upstream side of filter 104-1, or a filtration device in which a return flow path is formed that can return the purified liquid from the downstream side of filter 104-1 or filter 104-2 to the upstream side of filter 103.

[0192] [Method of manufacturing chemical solution] The method for producing a chemical liquid according to an embodiment of the present invention is a method for producing a chemical liquid by purifying a liquid to be purified to obtain a chemical liquid, and includes a filtration step in which the liquid to be purified is filtered using the filtration device already described to obtain the chemical liquid.

[0193] [Liquid to be purified] The liquid to be purified to which the method for producing a chemical solution according to an embodiment of the present invention can be applied is not particularly limited, but preferably contains a solvent. Examples of the solvent include organic solvents and water, and it is preferable that the liquid contains an organic solvent. Below, the following will be described separately for organic liquids to be purified, in which the content of organic solvents (the total content when multiple organic solvents are contained) exceeds 50 mass% relative to the total mass of solvents contained in the liquid to be purified, and for aqueous liquids, in which the content of water exceeds 50 mass% relative to the total mass of solvents contained in the liquid to be purified.

[0194] <Organic liquid to be purified> (organic solvent) The organic liquid to be purified contains an organic solvent, and the content of the organic solvent is more than 50 mass % relative to the total mass of the solvent contained in the liquid to be purified. The content of the organic solvent in the liquid to be purified is not particularly limited, but is generally preferably 99.0% by mass or more relative to the total mass of the liquid to be purified. The upper limit is not particularly limited, but is generally preferably 99.99999% by mass or less. The organic solvent may be used alone or in combination of two or more. When two or more organic solvents are used in combination, the total content is preferably within the above range.

[0195] In this specification, an organic solvent refers to a liquid organic compound contained in an amount exceeding 10,000 ppm by mass per component relative to the total mass of the liquid to be purified. In other words, in this specification, a liquid organic compound contained in an amount exceeding 10,000 ppm by mass relative to the total mass of the liquid to be purified corresponds to an organic solvent. In this specification, the term "liquid" means a state in which the substance is liquid at 25°C and atmospheric pressure.

[0196] The type of the organic solvent is not particularly limited, and known organic solvents can be used. Examples of the organic solvent include alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cyclic lactones (preferably having 4 to 10 carbon atoms), monoketone compounds which may have a ring (preferably having 4 to 10 carbon atoms), alkylene carbonates, alkyl alkoxyacetates, and alkyl pyruvates. Furthermore, as the organic solvent, for example, those described in JP-A-2016-57614, JP-A-2014-219664, JP-A-2016-138219, and JP-A-2015-135379 may be used.

[0197] The organic solvents used were propylene glycol monomethyl ether (PGMM), propylene glycol monoethyl ether (PGME), propylene glycol monopropyl ether (PGMP), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl methoxypropionate (MPM), cyclopentanone (CyPn), cyclohexanone (CyHe), γ-butyrolactone (γBL), diisoamyl ether (DIAE), butyl acetate (nBA), and acetic acid. At least one selected from the group consisting of isoamyl acetate (iAA), isopropanol (IPA), 4-methyl-2-pentanol (MIBC), dimethyl sulfoxide (DMSO), n-methyl-2-pyrrolidone (NMP), diethylene glycol (DEG), ethylene glycol (EG), dipropylene glycol (DPG), propylene glycol (PG), ethylene carbonate (EC), propylene carbonate (PC), sulfolane, cycloheptanone, and 2-heptanone (MAK) is preferred.

[0198] The type and content of the organic solvent in the liquid to be purified can be measured using a gas chromatograph mass spectrometer.

[0199] (Other ingredients) The liquid to be purified may contain other components in addition to those described above, such as inorganic substances (metal ions, metal particles, metal oxide particles, etc.), resins, organic substances other than resins, and water.

[0200] ·Inorganic matter The liquid to be purified may contain inorganic substances, which are not particularly limited and include metal ions and metal-containing particles.

[0201] The metal-containing particles may be any particles containing metal atoms, and the form of the particles is not particularly limited. For example, the particles may be simple metal atoms, compounds containing metal atoms (hereinafter also referred to as "metal compounds"), or composites thereof. The metal-containing particles may also contain multiple metal atoms.

[0202] The composite is not particularly limited, but examples thereof include so-called core-shell type particles having a simple metal atom and a metal compound that covers at least a part of the simple metal atom, solid solution particles containing a metal atom and other atoms, eutectic particles containing a metal atom and other atoms, aggregate particles of a simple metal atom and a metal compound, aggregate particles of different types of metal compounds, and metal compounds whose composition changes continuously or intermittently from the particle surface toward the center.

[0203] The atoms other than the metal atom contained in the metal compound are not particularly limited, and examples thereof include carbon atoms, oxygen atoms, nitrogen atoms, hydrogen atoms, sulfur atoms, and phosphorus atoms, with oxygen atoms being preferred.

[0204] The metal atoms are not particularly limited, but examples thereof include Fe atoms, Al atoms, Cr atoms, Ni atoms, Pb atoms, Zn atoms, and Ti atoms. The metal-containing particles may contain one type of the above metal atoms alone or two or more types in combination.

[0205] The inorganic substance may be added to the liquid to be purified, or may be unintentionally mixed into the liquid to be purified during the production process. Examples of unintentional mixing during the production process of the chemical include when the inorganic substance is contained in a raw material (e.g., an organic solvent) used in the production of the chemical, or when the inorganic substance is mixed during the production process of the chemical (e.g., contamination), but are not limited to the above.

[0206] (resin) The liquid to be purified may contain a resin. The resin is more preferably a resin P having a group that decomposes under the action of an acid to generate a polar group.The resin is more preferably a resin having a repeating unit represented by formula (AI) described below, which is a resin whose solubility in a developer mainly composed of an organic solvent decreases under the action of an acid.The resin having a repeating unit represented by formula (AI) described below has a group that decomposes under the action of an acid to generate an alkali-soluble group (hereinafter also referred to as an "acid-decomposable group"). Examples of polar groups include alkali-soluble groups, such as a carboxy group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a phenolic hydroxyl group, and a sulfo group.

[0207] In the acid-decomposable group, the polar group is protected by a group that is detached by an acid (acid-detachable group). Examples of the acid-detachable group include -C(R 36 )(R 37 )(R 38 ), -C(R 36 )(R 37 )(OR 39 ), and -C(R 01 )(R 02 )(OR 39 ) etc.

[0208] In the formula, R 36 ~R 39 R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. 36 and R 37 may be bonded to each other to form a ring.

[0209] R 01 and R 02 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

[0210] The resin P whose solubility in a developer containing an organic solvent as its main component decreases due to the action of an acid will be described in detail below.

[0211] (Formula (AI): Repeating unit having an acid-decomposable group) Resin P preferably contains a repeating unit represented by formula (AI).

[0212] [ka]

[0213] In formula (AI), Xa1 represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Ra1 to Ra3 each independently represent an alkyl group (straight-chain or branched) or a cycloalkyl group (monocyclic or polycyclic). Two of Ra1 to Ra3 may be bonded to form a cycloalkyl group (monocyclic or polycyclic).

[0214] Examples of the alkyl group represented by Xa1 that may have a substituent include a methyl group and -CH2-R 11 Examples of such groups include groups represented by R 11 represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Xa1 is preferably a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.

[0215] Examples of the divalent linking group for T include an alkylene group, a -COO-Rt- group, and a -O-Rt- group, where Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a -CH2- group, a -(CH2)2- group, or a -(CH2)3- group.

[0216] The alkyl groups Ra1 to Ra3 are preferably those having 1 to 4 carbon atoms.

[0217] The cycloalkyl groups of Ra1 to Ra3 are preferably monocyclic cycloalkyl groups such as a cyclopentyl group or a cyclohexyl group, or polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. The cycloalkyl group formed by combining two of Ra1 to Ra3 is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, and more preferably a monocyclic cycloalkyl group having 5 to 6 carbon atoms.

[0218] In the cycloalkyl group formed by combining two of Ra1 to Ra3, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, or a group having a heteroatom such as a carbonyl group.

[0219] In the repeating unit represented by formula (AI), for example, Ra1 is a methyl group or an ethyl group, and Ra2 and Ra3 are bonded to form the above-mentioned cycloalkyl group.

[0220] Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxy group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms), and the like, preferably having 8 or less carbon atoms.

[0221] The content of the repeating unit represented by formula (AI) is preferably from 20 to 90 mol %, more preferably from 25 to 85 mol %, and even more preferably from 30 to 80 mol %, based on all repeating units in the resin P.

[0222] (Repeating unit having a lactone structure) Furthermore, the resin P preferably contains a repeating unit Q having a lactone structure.

[0223] The repeating unit Q having a lactone structure preferably has a lactone structure in the side chain, and more preferably is a repeating unit derived from a (meth)acrylic acid derivative monomer. The repeating unit Q having a lactone structure may be used alone or in combination of two or more kinds, but it is preferred to use one kind alone. The content of the repeating unit Q having a lactone structure relative to all repeating units in the resin P is preferably from 3 to 80 mol %, more preferably from 3 to 60 mol %.

[0224] The lactone structure is preferably a 5- to 7-membered lactone structure, and more preferably a structure in which another ring structure is condensed with the 5- to 7-membered lactone structure to form a bicyclo structure or a spiro structure. The lactone structure preferably has a repeating unit having a lactone structure represented by any one of the following formulas (LC1-1) to (LC1-17): The lactone structure is more preferably a lactone structure represented by formula (LC1-1), (LC1-4), (LC1-5), or (LC1-8), and even more preferably a lactone structure represented by formula (LC1-4).

[0225] [ka]

[0226] The lactone structure portion may have a substituent (Rb2). Preferred examples of the substituent (Rb2) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, a carboxy group, a halogen atom, a hydroxyl group, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or greater, multiple substituents (Rb2) may be the same or different, and multiple substituents (Rb2) may be bonded to each other to form a ring.

[0227] (Repeating unit having a phenolic hydroxyl group) Furthermore, the resin P may contain a repeating unit having a phenolic hydroxyl group. Examples of the repeating unit having a phenolic hydroxyl group include a repeating unit represented by the following general formula (I).

[0228] [ka]

[0229] During the ceremony, R 41 , R 42 and R 43 each independently represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 42 may be bonded to Ar4 to form a ring, in which case R 42 represents a single bond or an alkylene group.

[0230] X4 is a single bond, -COO-, or -CONR 64 - represents R 64 represents a hydrogen atom or an alkyl group. L4 represents a single bond or an alkylene group. Ar4 represents an (n+1)-valent aromatic ring group, R 42 When it combines with the group to form a ring, it represents an (n+2)-valent aromatic ring group. n represents an integer of 1 to 5.

[0231] R in general formula (I) 41 , R 42 and R 43 The alkyl group is preferably an alkyl group having 20 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, or a dodecyl group, which may have a substituent, more preferably an alkyl group having 8 or less carbon atoms, and even more preferably an alkyl group having 3 or less carbon atoms.

[0232] R in general formula (I) 41 , R 42 and R 43 The cycloalkyl group may be monocyclic or polycyclic, and is preferably a monocyclic cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group, or a cyclohexyl group, which may have a substituent.

[0233] R in general formula (I) 41 , R42 and R 43 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, with a fluorine atom being preferred.

[0234] R in general formula (I) 41 , R 42 and R 43 The alkyl group contained in the alkoxycarbonyl group of the above R 41 , R 42 and R 43 The same alkyl groups as those in the above are preferred.

[0235] Examples of the substituent in each of the above groups include an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amido group, a ureido group, a urethane group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group, a thioether group, an acyl group, an acyloxy group, an alkoxycarbonyl group, a cyano group, and a nitro group, and the number of carbon atoms in the substituent is preferably 8 or less.

[0236] Ar4 represents an (n+1)-valent aromatic ring group. When n is 1, the divalent aromatic ring group may have a substituent, and examples thereof include arylene groups having 6 to 18 carbon atoms, such as a phenylene group, a tolylene group, a naphthylene group, and an anthracenylene group, and aromatic ring groups containing a heterocycle, such as thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0237] Specific examples of the (n+1)-valent aromatic ring group when n is an integer of 2 or greater include groups obtained by removing any (n-1) hydrogen atoms from the above-mentioned specific examples of the divalent aromatic ring group. The (n+1)-valent aromatic ring group may further have a substituent.

[0238] Examples of the substituent that the above-mentioned alkyl group, cycloalkyl group, alkoxycarbonyl group, alkylene group, and (n+1)-valent aromatic ring group may have include, for example, R41 , R 42 and R 43 alkoxy groups such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, and a butoxy group; and aryl groups such as a phenyl group.

[0239] -CONR represented by X4 64 -(R 64 represents a hydrogen atom or an alkyl group) 64 Examples of the alkyl group include alkyl groups having 20 or less carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, and dodecyl groups, which may have a substituent, and alkyl groups having 8 or less carbon atoms are more preferred.

[0240] X4 is preferably a single bond, -COO- or -CONH-, more preferably a single bond or -COO-.

[0241] The alkylene group in L4 is preferably an alkylene group having 1 to 8 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group, which may have a substituent.

[0242] Ar4 is preferably an aromatic ring group having 6 to 18 carbon atoms which may have a substituent, and more preferably a benzene ring group, a naphthalene ring group or a biphenylene ring group.

[0243] The repeating unit represented by general formula (I) preferably has a hydroxystyrene structure, that is, Ar4 is preferably a benzene ring group.

[0244] The content of repeating units having a phenolic hydroxyl group relative to all repeating units in the resin P is preferably from 0 to 50 mol %, more preferably from 0 to 45 mol %, and even more preferably from 0 to 40 mol %.

[0245] (Repeating unit containing an organic group having a polar group) Resin P may further contain a repeating unit containing an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, which improves substrate adhesion and developer affinity. The alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diadamantyl group, or a norbornane group, and the polar group is preferably a hydroxyl group or a cyano group.

[0246] When the resin P contains a repeating unit containing an organic group having a polar group, the content thereof is preferably 1 to 50 mol %, more preferably 1 to 30 mol %, still more preferably 5 to 25 mol %, and particularly preferably 5 to 20 mol %, based on the total repeating units in the resin P.

[0247] (Repeating unit represented by general formula (VI)) Resin P may contain a repeating unit represented by the following general formula (VI).

[0248] [ka]

[0249] In general formula (VI), R 61 , R 62 and R 63 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. 62 may be bonded to Ar6 to form a ring, in which case R 62 represents a single bond or an alkylene group. X6 is a single bond, -COO-, or -CONR 64 - represents R 64 represents a hydrogen atom or an alkyl group. L6 represents a single bond or an alkylene group. Ar6 represents an (n+1)-valent aromatic ring group, R 62 When it combines with the group to form a ring, it represents an (n+2)-valent aromatic ring group. When n≧2, each Y2 independently represents a hydrogen atom or a group which is eliminated by the action of an acid, provided that at least one Y2 represents a group which is eliminated by the action of an acid. n represents an integer of 1 to 4.

[0250] As the group Y2 that is eliminated by the action of an acid, a structure represented by the following general formula (VI-A) is preferred.

[0251] [ka]

[0252] L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group formed by combining an alkylene group with an aryl group. M represents a single bond or a divalent linking group. Q represents an alkyl group, a cycloalkyl group which may contain a heteroatom, an aryl group which may contain a heteroatom, an amino group, an ammonium group, a mercapto group, a cyano group, or an aldehyde group. At least two of Q, M and L1 may be bonded to form a ring (preferably a 5- or 6-membered ring).

[0253] The repeating unit represented by the above general formula (VI) is preferably a repeating unit represented by the following general formula (3).

[0254] [ka]

[0255] In general formula (3), Ar3 represents an aromatic ring group. R3 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group, an acyl group, or a heterocyclic group. M3 represents a single bond or a divalent linking group. Q3 represents an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group. At least two of Q3, M3 and R3 may be bonded to form a ring.

[0256] The aromatic ring group represented by Ar3 is the same as Ar6 in the above general formula (VI) when n is 1, and is preferably a phenylene group or a naphthylene group, more preferably a phenylene group.

[0257] (Repeating unit having a silicon atom in the side chain) Resin P may further contain a repeating unit having a silicon atom in the side chain. Examples of repeating units having a silicon atom in the side chain include (meth)acrylate repeating units having a silicon atom and vinyl repeating units having a silicon atom. The repeating unit having a silicon atom in the side chain is typically a repeating unit having a group having a silicon atom in the side chain, and examples of the group having a silicon atom include a trimethylsilyl group, a triethylsilyl group, a triphenylsilyl group, a tricyclohexylsilyl group, a tristrimethylsiloxysilyl group, a tristrimethylsilylsilyl group, a methylbistrimethylsilylsilyl group, a methylbistrimethylsiloxysilyl group, a dimethyltrimethylsilylsilyl group, a dimethyltrimethylsiloxysilyl group, and cyclic or linear polysiloxanes, or cage, ladder, or random silsesquioxane structures such as those shown below. In the formula, R and R 1 Each independently represents a monovalent substituent. * represents a bond.

[0258] [ka]

[0259] Preferred examples of repeating units having the above group include repeating units derived from an acrylate compound or methacrylate compound having the above group, and repeating units derived from a compound having the above group and a vinyl group.

[0260] When the resin P has the repeating unit having a silicon atom in the side chain, the content thereof is preferably 1 to 30 mol %, more preferably 5 to 25 mol %, and even more preferably 5 to 20 mol %, based on the total repeating units in the resin P.

[0261] The weight-average molecular weight of Resin P, as measured by GPC (Gel Permeation Chromatography) in terms of polystyrene, is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000. By setting the weight-average molecular weight to 1,000 to 200,000, it is possible to prevent deterioration in heat resistance and dry etching resistance, and also to prevent deterioration in developability and deterioration in film-formability due to an increase in viscosity.

[0262] The dispersity (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0.

[0263] Other components contained in the chemical solution (for example, acid generator, basic compound, quencher, hydrophobic resin, surfactant, solvent, etc.) can all be known components.

[0264] <Aqueous liquid to be purified> An aqueous liquid to be purified means a liquid to be purified that contains more than 50% by mass of water relative to the total mass of the solvents contained in the liquid to be purified, and preferably 51 to 95% by mass of the total mass of the solvents contained in the liquid to be purified. The water is not particularly limited, but is preferably ultrapure water used in semiconductor manufacturing, and more preferably water obtained by further purifying the ultrapure water to reduce inorganic anions, metal ions, etc. The purification method is not particularly limited, but purification using a filtration membrane or an ion exchange membrane, and purification by distillation are preferred. Furthermore, it is preferable to purify the water by the method described in JP 2007-254168 A, for example.

[0265] (oxidizing agent) The aqueous solution to be purified may contain an oxidizing agent, but the oxidizing agent is not particularly limited and any known oxidizing agent can be used, such as hydrogen peroxide, peroxide, nitric acid, nitrate, iodate, periodate, hypochlorite, chlorite, chlorate, perchlorate, persulfate, dichromate, permanganate, ozone water, silver(II) salt, and iron(III) salt.

[0266] The content of the oxidizing agent is not particularly limited, and may be any amount depending on the application. For example, the content is preferably 0.1 mass % or more and preferably 99 mass % or less relative to the total mass of the aqueous liquid to be purified. The oxidizing agent may be used alone or in combination with two or more. When two or more oxidizing agents are used in combination, the total content is preferably within the above range.

[0267] (Inorganic acid) The aqueous liquid to be purified may contain an inorganic acid. There are no particular limitations on the inorganic acid, and any known inorganic acid can be used. Examples of inorganic acids include sulfuric acid, phosphoric acid, and hydrochloric acid. Note that inorganic acids are not included in the oxidizing agents described above. The content of inorganic acid in the liquid to be purified is not particularly limited, but is preferably 0.01% by mass or more, and more preferably 99% by mass or less, based on the total mass of the liquid to be purified. The inorganic acid may be used alone or in combination of two or more. When two or more inorganic acids are used in combination, the total content is preferably within the above range.

[0268] (corrosion inhibitor) The aqueous solution to be purified may contain a corrosion inhibitor. There are no particular limitations on the corrosion inhibitor, and known corrosion inhibitors can be used. Examples of corrosion inhibitors include 1,2,4-triazole (TAZ), 5-aminotetrazole (ATA), 5-amino-1,3,4-thiadiazole-2-thiol, 3-amino-1H-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, tolyltriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, 1-amino-1,2,3-triazole, and 1-amino-5-methyl-1,2,3-triazole. Triazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, naphthotriazole, 1H-tetrazole-5-acetic acid, 2-mercaptobenzothiazole (2-MBT), 1-phenyl-2-tetrazoline-5-thione, 2-mercaptobenzimidazole (2-MBI), 4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 2,4-diamino-6-methyl-1,3,5-triazine, thiazole, imine dazole, benzimidazole, triazine, methyltetrazole, bismuthiol I, 1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, imidazolinethione, 4-methyl-4H-1,2,4-triazole-3-thiol, 5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, tritolyl phosphate, indazole, adenine, cytosine Synthin, guanine, thymine, phosphate inhibitors, amines, pyrazoles, propanethiol, silanes, secondary amines, benzohydroxamic acids, heterocyclic nitrogen inhibitors, ascorbic acid, thiourea, 1,1,3,3-tetramethylurea, urea, urea derivatives, uric acid, potassium ethylxanthate, glycine, dodecylphosphonic acid, iminodiacetic acid, boric acid, malonic acid, succinic acid, nitrilotriacetic acid, sulfolane, 2,3,5-trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, quinoxaline, acetylpyrrole, pyridazine, histadine, pyrazine, glutathione (reduced form), cysteine, cystine, thiophene, mercaptopyridine N-oxide, thiamine HCl, tetraethylthiuram disulfide, 2,5-dimercapto-1,3-thiadiazole ascorbic acid, catechol, t-butylcatechol, phenol, and pyrogallol.

[0269] Examples of the anticorrosive agent that can be used include aliphatic carboxylic acids such as dodecanoic acid, palmitic acid, 2-ethylhexanoic acid, and cyclohexanoic acid; and carboxylic acids having chelating ability such as citric acid, malic acid, oxalic acid, malonic acid, succinic acid, itaconic acid, maleic acid, glycolic acid, mercaptoacetic acid, thioglycolic acid, salicylic acid, sulfosalicylic acid, anthranilic acid, N-methylanthranilic acid, 3-amino-2-naphthoic acid, 1-amino-2-naphthoic acid, 2-amino-1-naphthoic acid, 1-aminoanthraquinone-2-carboxylic acid, tannic acid, and gallic acid.

[0270] Examples of the anticorrosive agent include anionic surfactants such as coconut fatty acid salts, castor sulfated oil salts, lauryl sulfate salts, polyoxyalkylene allyl phenyl ether sulfate salts, alkyl benzene sulfonic acid, alkyl benzene sulfonates, alkyl diphenyl ether disulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinate salts, isopropyl phosphate, polyoxyethylene alkyl ether phosphate salts, and polyoxyethylene allyl phenyl ether phosphate salts; cationic surfactants such as oleylamine acetate, lauryl pyridinium chloride, cetyl pyridinium chloride, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, and didecyl dimethyl ammonium chloride; and amphoteric surfactants such as coconut alkyl dimethyl amine oxide, fatty acid amidopropyl dimethyl amine oxide, alkyl polyaminoethyl glycine hydrochloride, amido betaine-type surfactants, alanine-type surfactants, and lauryliminodipropionic acid. Surfactants: nonionic surfactants of polyoxyalkylene primary alkyl ethers or polyoxyalkylene secondary alkyl ethers, such as polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene laurylamine, polyoxyethylene oleylamine, polyoxyethylene polystyrylphenyl ether, and polyoxyalkylene polystyrylphenyl ether; other polyoxyalkylene-based nonionic surfactants, such as polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylenated castor oil, polyoxyethylenated hydrogenated castor oil, sorbitan laurate, polyoxyethylene sorbitan laurate, and fatty acid diethanolamides; fatty acid alkyl esters, such as octyl stearate and trimethylolpropane tridecanoate; and polyether polyols, such as polyoxyalkylene butyl ether, polyoxyalkylene oleyl ether, and trimethylolpropane tris(polyoxyalkylene) ether, can also be used. Examples of the commercially available products include Newkalgen FS-3PG (manufactured by Takemoto Yushi Co., Ltd.) and Hosten HLP-1 (manufactured by Nikko Chemicals Co., Ltd.).

[0271] Furthermore, a hydrophilic polymer can also be used as the anticorrosive agent. Examples of hydrophilic polymers include polyglycols such as polyethylene glycol, alkyl ethers of polyglycols, polyvinyl alcohol, polyvinylpyrrolidone, polysaccharides such as alginic acid, carboxylic acid-containing polymers such as polymethacrylic acid and polyacrylic acid, polyacrylamide, polymethacrylamide, polyethyleneimine, etc. Specific examples of such hydrophilic polymers include water-soluble polymers described in paragraphs 0042 to 0044 of JP 2009-88243 A and paragraph 0026 of JP 2007-194261 A.

[0272] Cerium salts can also be used as anticorrosive agents. The cerium salt is not particularly limited, and any known cerium salt can be used. Examples of cerium salts include trivalent cerium salts such as cerium acetate, cerium nitrate, cerium chloride, cerium carbonate, cerium oxalate, and cerium sulfate, and examples of tetravalent cerium salts include cerium sulfate, ammonium cerium sulfate, ammonium cerium nitrate, diammonium cerium nitrate, and cerium hydroxide.

[0273] The corrosion inhibitor may include a substituted or unsubstituted benzotriazole. Suitable substituted benzotriazoles include, but are not limited to, benzotriazoles substituted with alkyl, aryl, halogen, amino, nitro, alkoxy, or hydroxyl groups. Substituted benzotriazoles also include those fused with one or more aryl (e.g., phenyl) or heteroaryl groups.

[0274] The content of the anticorrosive agent in the liquid to be purified is preferably adjusted to 0.01 to 5 mass%, more preferably 0.05 to 5 mass%, and even more preferably 0.1 to 3 mass%, relative to the total mass of the chemical liquid. The anticorrosive agent may be used alone or in combination of two or more. When two or more anticorrosive agents are used in combination, the total content is preferably within the above range.

[0275] (organic solvent) The aqueous liquid to be purified may contain an organic solvent. The organic solvent is not particularly limited, but is as already described for the organic solvent-based liquid to be purified. When an organic solvent is contained, the content of the organic solvent is preferably 5 to 35 mass% relative to the total mass of the solvents contained in the liquid to be purified.

[0276] <Relationship between the liquid to be purified and the filtration device> There are no particular restrictions on the relationship between the liquid to be purified and the filtration device (physical properties of the filter), but in terms of the relationship with the solubility parameter (SP value) of the liquid to be purified, the SP value should be 20 (MPa) 1 / 2 When the SP value is less than 1.0, the imidization ratio of the filter A is preferably 1.0 to 1.5. The lower limit of the SP value is not particularly limited, but is generally 14 (MPa). 1 / 2 The above is preferable. On the other hand, the SP value is 20 (MPa) 1 / 2 If it is more than 30 (MPa) (the upper limit is not particularly limited) 1 / 2 Preferably, the imidization ratio is not more than 1.5. There is no particular upper limit to the imidization ratio, but it is generally preferably 2.0 or less.

[0277] Furthermore, according to the study by the present inventors, the SP value of the liquid to be purified is 20 (MPa). 1 / 2 If the SP value of the liquid to be purified is 20 (MPa), it is known that the liquid to be purified often contains highly polar solid impurities (especially small gel-like components). 1 / 2In this case, it is preferable to use filter A having an imidization ratio of more than 1.5, since it has a greater interaction with such gel-like impurities (higher capturing ability).

[0278] On the other hand, the SP value is 20 (MPa) 1 / 2 When the imidization ratio is less than 1.5, the content of the gel-like impurities in the purified liquid is relatively small, and therefore, when the imidization ratio of Filter A is 1.0 or more, the gel-like impurities can be sufficiently captured. On the other hand, when the imidization ratio is 1.5 or less, Filter A exhibits sufficient performance in removing ionic impurities, resulting in a chemical liquid with better defect suppression performance.

[0279] In this specification, the term "SP value" means "the value of the solubility parameter." The SP value in the present invention is the Hansen solubility parameter according to the formula explained in "Hansen Solubility Parameters: A User's Handbook, Second Edition, C.M. Hansen (2007), Taylor and Francis Group, LLC (HSPiP Manual)," and the SP value is calculated using the following formula using "Practical Hansen Solubility Parameters HSPiP Third Edition" (software version 4.0.05). (SP value) 2 =(δHd) 2 +(δHp) 2 +(δHh) 2 Hd: dispersion term Hp: polarity term Hh: hydrogen bond term

[0280] When the liquid to be purified is a mixture of two or more solvents, the SP value of the liquid to be purified can be calculated by the sum of the products of the SP values ​​of each of the solvents and the volume fractions of each solvent, as expressed by the following formula: (SP value of the liquid to be purified) = Σ{(SP value of each solvent) × (volume fraction of each solvent)} For example, if the solvent contained in the liquid to be purified is a 7:3 (volume basis) mixture of PGMEA and PGME, the SP value is calculated as 17.8 x 0.7 + 23.05 x 0.3, which is 19.375 (MPa). 1 / 2 In this specification, the SP value is expressed as (MPa) 1 / 2 In the above case, the SP value of the purified liquid is 19.4 (MPa) as shown in the table in the example below. 1 / 2 Let's say.

[0281] [Filtration process] The method for producing a chemical solution according to this embodiment includes a filtration step in which the liquid to be purified is filtered using the filtering device already described to obtain a chemical solution. The filtration device has a flow passage formed by arranging in series a filter A and a filter B. The supply pressure of the liquid to be purified to each filter is not particularly limited, but is generally preferably 0.00010 to 1.0 MPa. In particular, the supply pressure P2 is preferably 0.00050 to 0.090 MPa, more preferably 0.0010 to 0.050 MPa, and even more preferably 0.0050 to 0.040 MPa, in that a chemical solution having better defect suppression performance can be obtained. Furthermore, since the filtration pressure affects the filtration accuracy, it is preferable that the pressure pulsation during filtration be as small as possible.

[0282] The filtration rate is not particularly limited, but is preferably 1.0 L / min / m because it is easy to obtain a chemical solution with better defect suppression performance. 2 More than 0.75L / min / m is preferable. 2 More preferably, 0.6 L / min / m 2 The above is more preferable. Filters have a pressure tolerance that ensures filter performance (the filter will not break), and if this value is large, the filtration speed can be increased by increasing the filtration pressure. In other words, the upper limit of the filtration speed usually depends on the pressure tolerance of the filter, but is usually 10.0 L / min / m 2 The following is preferred:

[0283] The temperature at which the liquid to be purified is passed through the filter is not particularly limited, but is generally preferably below room temperature.

[0284] The filtration step is preferably carried out in a clean environment. Specifically, it is preferably carried out in a clean room that satisfies Class 1000 (Class 6 in ISO14644-1:2015) of the US Federal Standards (Fed. Std. 209E), more preferably Class 100 (Class 5 in ISO14644-1:2015), even more preferably Class 10 (Class 4 in ISO14644-1:2015), and particularly preferably a clean room with a cleanliness of Class 1 (Class 3 in ISO14644-1:2015) or higher (Class 2 or Class 1). It is preferable that each step described below is also carried out in the above-mentioned clean environment.

[0285] Furthermore, if the filtration device has a return flow path, the filtration step may be a circulating filtration step, in which the purified liquid is filtered at least through filter A, and the purified liquid after filtration through filter A is returned to the flow path upstream of filter A and filtered again through filter A. The number of times of circulating filtration is not particularly limited, but is generally preferably 1 to 10. Circulating filtration can be performed by returning the purified liquid upstream of filter A so that filtration through filter A is repeated. In this case, the return flow path may be adjusted so that filtration through at least one filter B is also repeated in addition to filter A.

[0286] [Other steps] The method for producing a chemical solution according to this embodiment may include other steps, such as a filter cleaning step, an apparatus cleaning step, a static elimination step, and a step of preparing a solution to be purified. Each step will be described in detail below.

[0287] <Filter cleaning process> The filter washing step is a step of washing Filter A and Filter B with a washing liquid before the filtration step. The method for washing the filters is not particularly limited, and examples thereof include a method of immersing the filters in the washing liquid, a method of passing the washing liquid through the filters, and a combination thereof.

[0288] (Immerse the filter in the cleaning solution) As a method for immersing the filter in the cleaning liquid, for example, a method in which an immersion container is filled with the cleaning liquid and the filter is immersed in the cleaning liquid can be mentioned.

[0289] Cleaning solution The cleaning liquid is not particularly limited, and any known cleaning liquid can be used. Among these, in terms of obtaining more excellent effects of the present invention, it is preferable that the cleaning liquid contains at least one selected from the group consisting of hydroxyaliphatic carboxylic acid esters, aliphatic carboxylic acid esters, linear or cyclic ketones, alkylene glycol monoalkyl ethers, alkylene glycol monoalkyl ether acetates, and aprotic polar solvents. A cleaning liquid that satisfies the above conditions will be referred to as a "specific cleaning liquid" below.

[0290] The specific cleaning solution contains at least one solvent selected from the group consisting of hydroxyaliphatic carboxylic acid esters, aliphatic carboxylic acid esters, linear or cyclic ketones, alkylene glycol monoalkyl ethers, alkylene glycol monoalkyl ether acetates, and aprotic polar solvents other than these solvents. Note that "aprotic polar solvents other than these solvents" is the same as "(A) aprotic polar solvents other than the solvent (B) below" below. The specific cleaning solution is (A) an aprotic polar solvent other than the solvent (B) below; It is preferable that the composition contains at least one solvent (B) selected from the group consisting of hydroxyaliphatic carboxylic acid esters, aliphatic carboxylic acid esters, linear or cyclic ketones, alkylene glycol monoalkyl ethers, and alkylene glycol monoalkyl ether acetates (hereinafter also referred to as "(B) solvent").

[0291] The aprotic polar solvent is preferably at least one selected from the group consisting of solvents having an amide structure represented by the following general formula (s) and alkylsulfinylalkanes (also known as dialkyl sulfoxides). The aprotic polar solvent may be used alone or in combination of two or more. [ka]

[0292] In the formula, R 1 and R 2 each independently represents a hydrogen atom or an alkyl group, and may be the same or different; R 3 is a hydrogen atom, an alkyl group, or -NR 4 R 5 R represents a group represented by the formula: 4 and R 5 R each independently represents a hydrogen atom or an alkyl group, and may be the same or different. 2 and R 3 may be bonded to each other to form a ring.

[0293] R 1 ~R 5 The alkyl group represented by is not particularly limited, but is preferably an alkyl group having 1 to 3 carbon atoms. R 2 and R 3 Examples of the ring formed by bonding together include a 2-imidazolidone ring, a 2-pyrrolidone ring, and a 3,4,5,6-tetrahydro-2(1H)-pyrimidinone ring.

[0294] Examples of solvents having an amide structure represented by the above general formula (s) include 1,1,3,3-tetramethylurea, 1,1,3,3-tetraethylurea, dimethylformamide, diethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidone, N-methylpyrrolidone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, N,N-dimethylpropionamide, N-methylacetamide, and N-methylformamide. Examples of the alkylsulfinylalkane (also known as dialkyl sulfoxide) include dimethyl sulfoxide and methyl ethyl sulfoxide.

[0295] The aprotic polar solvent is more preferably at least one selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 1,1,3,3-tetramethylurea, and dimethyl sulfoxide.

[0296] The solvent (B) is at least one solvent selected from the group consisting of hydroxyaliphatic carboxylic acid esters, aliphatic carboxylic acid esters, linear or cyclic ketones, alkylene glycol monoalkyl ethers, and alkylene glycol monoalkyl ether acetates. Aliphatic carboxylic acid esters do not include hydroxyaliphatic carboxylic acid esters. Examples of the hydroxyaliphatic carboxylic acid ester include methyl lactate and ethyl lactate. Examples of the aliphatic carboxylic acid ester include n-butyl acetate, iso-butyl acetate, and n-propyl acetate. Examples of the chain or cyclic ketone include 2-heptanone (also known as methyl amyl ketone) and cyclohexanone. Examples of alkylene glycol monoalkyl ethers include propylene glycol monoalkyl ether, butylene glycol monoalkyl ether, and pentane glycol monoalkyl ether, with propylene glycol monomethyl ether being preferred. Examples of the alkylene glycol monoalkyl ether acetate include propylene glycol monoalkyl ether acetate, butylene glycol monoalkyl ether acetate, and pentane glycol monoalkyl ether acetate, with propylene glycol monomethyl ether acetate being preferred. The (B) solvent is preferably a compound having 4 to 7 carbon atoms, and more preferably a compound having 5 to 7 carbon atoms. The (B) solvent is preferably at least one selected from the group consisting of ethyl lactate, butyl acetate, 2-heptanone, cyclohexanone, and propylene glycol monomethyl ether acetate.

[0297] The aprotic polar solvent may be used alone, or the (B) solvent may be used alone. When the aprotic polar solvent and the (B) solvent are mixed and used, the mixing ratio is not particularly limited, but the mass ratio of the (B) solvent to the total of the aprotic polar solvent and the (B) solvent [B / (A+B)] is preferably 0.8 or less, more preferably 0.7 or less, even more preferably 0.5 or less, and particularly preferably 0.4 or less. The content mass ratio of the solvent (B) [B / (A+B)] is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more.

[0298] The time for which the filter is immersed in the cleaning solution is not particularly limited, but is preferably 7 days to 1 year in order to obtain better effects of the present invention. The temperature of the immersion liquid is not particularly limited, but is preferably 20° C. or higher in order to obtain a better effect of the present invention.

[0299] The housing of the filter unit in the filtration device already described can also be used as the immersion container. That is, a method can be used in which a filter (typically a filter cartridge) is housed in the housing of the filtration device, the housing is filled with the cleaning solution, and the housing is left to stand in that state. In addition to the above, there is also a method in which an immersion container is prepared separately from the housing of the purification device (i.e., an immersion container is prepared outside the purification device), the separately prepared immersion container is filled with cleaning liquid, and the filter is immersed in the cleaning liquid. Among these, a method in which an immersion container prepared outside the filtration device is filled with the cleaning solution and the filter is immersed in the cleaning solution is preferred, since impurities eluted from the filter do not get mixed into the filtration device.

[0300] The shape and size of the immersion container are not particularly limited and can be appropriately selected depending on the number and size of the filters to be immersed. The immersion vessel is not particularly limited, but it is preferable that at least the liquid-contacting portion is made of the corrosion-resistant material already described. Furthermore, the material components of the immersion container preferably contain at least one selected from the group consisting of polyfluorocarbons (PTFE, PFA: perfluoroalkoxyalkane, and PCTFE: polychlorotrifluoroethylene, etc.), PPS (polyphenylene sulfide), POM (polyoxymethylene), and polyolefins (PP, PE, etc.), more preferably at least one selected from the group consisting of polyfluorocarbons, PPS, and POM, even more preferably polyfluorocarbons, particularly preferably at least one selected from the group consisting of PTFE, PFA, and PCTFE, and most preferably PTFE. The immersion container is preferably washed before use, and is preferably washed using a washing liquid (so-called co-washing).

[0301] (A method of cleaning the filter by passing a cleaning solution through it) The method for passing a cleaning liquid through a filter to clean it is not particularly limited, but an example thereof is a method in which a filter (typically a filter cartridge) is housed in a filter housing of a filter unit of the filtration device already described, and a cleaning liquid is introduced into the filter housing to pass the cleaning liquid through the filter.

[0302] During cleaning, impurities adhering to the filter migrate (typically dissolve) into the cleaning liquid, increasing the impurity content in the cleaning liquid. Therefore, it is preferable that cleaning liquid that has been passed through the filter once is not reused for cleaning, but is instead discharged outside the filtration device. In other words, it is preferable not to use circulating cleaning.

[0303] Another example of the method of cleaning a filter by passing a cleaning liquid through it is a method of cleaning the filter using a cleaning device. In this specification, the cleaning device means a device that is different from the filtration device and is installed outside the filtration device. The type of the cleaning device is not particularly limited, and a device with a configuration similar to that of the filtration device can be used.

[0304] The cleaning liquid used when passing it through the filter to clean it is not particularly limited, and any known cleaning liquid can be used. In particular, the form of the cleaning liquid is preferably the same as the cleaning liquid used for immersion as described above, in that more excellent effects of the present invention can be obtained.

[0305] <Equipment cleaning process> The device cleaning step is a step of cleaning the liquid-contacting parts of the filtration device with a cleaning liquid before the filtration step. There are no particular limitations on the method for cleaning the liquid-contacting parts of the filtration device before the filtration step. In the following, an example of a filtration device in which the filter is a cartridge filter and the cartridge filter is housed in a housing arranged on a flow path will be described.

[0306] The device cleaning process preferably includes a step A in which the liquid-contacting parts of the filtration device are cleaned with a cleaning liquid after the cartridge filter has been removed from the housing, and a step B in which, after step A, the cartridge filter is placed in the housing and the liquid-contacting parts of the filtration device are cleaned with a cleaning liquid.

[0307] ·Process A Step A is a step of cleaning the liquid-contacting parts of the filtration device with a cleaning liquid, with the cartridge filter removed from the housing. "With the filter removed from the housing" means cleaning the liquid-contacting parts of the filtration device with a cleaning liquid before removing the filter cartridge from the housing or before installing the filter cartridge in the housing. There are no particular limitations on the method for cleaning the liquid-contacting parts of a filtration device with a cleaning liquid when the filter has been removed from the housing (hereinafter also referred to as "without a filter installed"), including the method of introducing the cleaning liquid from the inlet and collecting it from the outlet.

[0308] Among these, a method for cleaning the liquid-contacting portion of a filtration device not housing a filter using a cleaning liquid, which can achieve a more excellent effect of the present invention, is to fill the interior of the filtration device not housing a filter with the cleaning liquid. By filling the interior of the filtration device not housing a filter with the cleaning liquid, the liquid-contacting portion of the filtration device not housing a filter comes into contact with the cleaning liquid. As a result, impurities adhering to the liquid-contacting portion of the filtration device are transferred (typically eluted) into the cleaning liquid. Then, the cleaning liquid after cleaning can be discharged outside the filtration device (typically from an outlet).

[0309] Cleaning solution The cleaning liquid is not particularly limited, and any known cleaning liquid can be used. In particular, it is preferable to use the cleaning liquid for immersing a filter, as described above, in order to obtain a more excellent effect of the present invention.

[0310] ·Process B Step B is a method of cleaning the filtration device with a cleaning liquid while the filter is stored in the housing. As a method for cleaning the filtration device using a cleaning liquid, in addition to the cleaning method in step A already described, a method of passing a cleaning liquid through the filtration device can also be used. There are no particular restrictions on the method for passing a cleaning liquid through the filtration device, and the cleaning liquid may be introduced from the inlet and discharged from the outlet. There are no particular restrictions on the cleaning liquid that can be used in this step, and the cleaning liquid described in step A can be used.

[0311] <Static elimination process> The static elimination step is a step of eliminating static electricity from the liquid to be purified to reduce the charged potential of the liquid to be purified. The static elimination method is not particularly limited, and any known static elimination method can be used. For example, a method of bringing the liquid to be purified into contact with a conductive material can be mentioned as a static elimination method. The contact time for the liquid to be purified with the conductive material component is preferably 0.001 to 60 seconds, more preferably 0.001 to 1 second, and even more preferably 0.01 to 0.1 second. Examples of the conductive material component include stainless steel, gold, platinum, diamond, and glassy carbon. One method for bringing the liquid to be purified into contact with a conductive material is to place a grounded mesh made of a conductive material across the flow path and pass the liquid to be purified through it.

[0312] <Preparation process of liquid to be purified> The purification target liquid preparation step is a step of preparing a purification target liquid to be introduced into the inlet of the filtration device. The method for preparing the purification target liquid is not particularly limited. Typical examples include a method of purchasing a commercially available product (e.g., a product called a "high purity grade product"), a method of obtaining the purification target liquid by reacting one or more raw materials, and a method of dissolving each component in a solvent.

[0313] The method for reacting raw materials to obtain a liquid to be purified (typically, a liquid to be purified containing an organic solvent) is not particularly limited, and known methods can be used. For example, there is a method in which one or more raw materials are reacted in the presence of a catalyst to obtain a liquid to be purified containing an organic solvent. More specifically, examples of such methods include a method of reacting acetic acid with n-butanol in the presence of sulfuric acid to obtain butyl acetate; a method of reacting ethylene, oxygen, and water in the presence of Al(C2H5)3 to obtain 1-hexanol; a method of reacting cis-4-methyl-2-pentene in the presence of Ipc2BH (Diisopinocampheylborane) to obtain 4-methyl-2-pentanol; a method of reacting propylene oxide, methanol, and acetic acid in the presence of sulfuric acid to obtain PGMEA (propylene glycol 1-monomethyl ether 2-acetate); a method of reacting acetone and hydrogen in the presence of copper oxide-zinc oxide-aluminum oxide to obtain IPA (isopropyl alcohol); and a method of reacting lactic acid and ethanol to obtain ethyl lactate.

[0314] This process may also include a pre-purification step in which the liquid to be purified is purified in advance before being introduced into the filtration device. The pre-purification step is not particularly limited, but may include a method in which the liquid to be purified is purified using a distillation device.

[0315] In the preliminary purification step, the method for purifying the purified liquid using a distillation apparatus is not particularly limited, and examples include a method in which the purified liquid is purified in advance using a distillation apparatus prepared separately from the filtration apparatus to obtain a distilled purified liquid, which is then stored in a portable tank and transported to the filtration apparatus for introduction, and a method using a purification apparatus described below.

[0316] First, a method of purifying the liquid to be purified in advance using a distillation apparatus prepared separately from the filtration apparatus (preliminary purification step) will be described with reference to FIG. FIG. 11 is a schematic diagram showing the relationship between the various devices when a liquid drug is produced using a distilled purified liquid that has been previously purified in a distiller. In FIG. 11, the configuration of the filtration device 400 is the same as that of the filtration device according to the third embodiment of the present invention already described, and therefore a description thereof will be omitted.

[0317] A chemical manufacturing site 1100 is equipped with a filtration device 400 and a distillation device 1101. The distillation device 1101 has a tank 401(a), a distiller 1102, and a portable tank 1103, which are connected to each other by piping 1104 and piping 1105, and a flow path S11 is formed by the tank 401(a), piping 1104, the distiller 1102, piping 1105, and the portable tank 1103. The shape of the tank 401(a) and each piping is not particularly limited, and tanks and piping of the same shape as those described as the tanks and piping of the filtration device according to the embodiment of the present invention can be used. The shape of the distiller 1102 can be the same as the distiller of the purification device according to the embodiment of the present invention, and its shape will be described later.

[0318] In distillation apparatus 1101, the liquid to be purified introduced into tank 401(a) is distilled in distiller 1102, and the resulting distilled liquid to be purified is stored in portable tank 1103. The form of the portable tank is not particularly limited, but it is preferable that at least a portion of the liquid-contacting part (preferably 90% or more of the surface area of ​​the liquid-contacting part, more preferably 99% or more of the surface area of ​​the liquid-contacting part) is made of a corrosion-resistant material described below.

[0319] The distilled purified liquid stored in the portable tank 1103 is transported by the transport means 1106 (flow F1 in Figure 9), and then the distilled purified liquid is introduced into the filtration device 400 from the inlet 101 of the filtration device.

[0320] Although FIG. 11 illustrates a configuration in which the distillation apparatus and the filtration apparatus are arranged in the same manufacturing plant, the distillation apparatus and the filtration apparatus may be arranged in different manufacturing plants.

[0321] Next, the preliminary purification step using a purification apparatus having a distiller and a filtration device will be described. First, the purification apparatus used in this step will be described. (purification equipment) The purification apparatus used in this step is a purification apparatus having the filtration apparatus already described. A purification apparatus according to an embodiment of the present invention includes the filtration apparatus already described, a second inlet, a second outlet, and at least one distiller disposed between the second inlet and the second outlet, in which the second outlet is connected to the inlet of the filtration apparatus already described, and a flow path is formed from the second inlet to the outlet of the filtration apparatus. The purification apparatus will be described below with reference to the drawings. In the following description, the details regarding the configuration of the filtration device are the same as those already explained, and therefore will not be explained again.

[0322] First embodiment of the refining device 12 is a schematic diagram showing a first embodiment of the purification device of the present invention. The purification device 1200 has a second inlet 1201, a second outlet 1202, and a distiller 1203 arranged between the second inlet 1201 and the second outlet 1202, and the second outlet 1202 is connected to the inlet 101 of the filtration device. As a result, in the purification device 1200, A flow path S12 is formed by the second inlet portion 1201, the distiller 1203, the second outlet portion 1202, the inlet portion 101, the filter 103 (filter A), the pipe 105, the filter 104 (filter BD), and the outlet portion 102. That is, the distiller 1203 is connected to the inlet 101 of the filtration device 100 .

[0323] The liquid to be purified that flows into the purification device 1200 from the second inlet 1201 is distilled in the distiller 1203, passes through the second outlet 1202, and is introduced into the filtration device 100 from the inlet 101. When the preliminary purification step is performed using this purification device, the next step (filtration step) can be performed without releasing the distilled liquid to be purified outside the device, thereby obtaining a chemical solution with better defect suppression performance.

[0324] The form of distiller 1203 is not particularly limited, and a known distiller (for example, a distillation column) can be used. The same materials as those for the housing already described can be used as the material for distiller 1203, and it is particularly preferred that at least a portion of the liquid-contacting portion of distiller 1203 be made of a corrosion-resistant material, which will be described later, and it is preferred that 90% or more of the area of ​​the liquid-contacting portion be made of a corrosion-resistant material, and it is even more preferred that 99% of the area of ​​the liquid-contacting portion be made of a corrosion-resistant material.

[0325] The distiller is not particularly limited, and known distillers can be used. The distiller may be either a batch type or a continuous type, with a continuous type being preferred. The distiller may also have packing inside. The form of the packing is not particularly limited, but it is preferred that at least a portion of the liquid-contacting part is made of a corrosion-resistant material as described below, and it is preferred that 90% or more of the area of ​​the liquid-contacting part is made of a corrosion-resistant material, and more preferred that 99% of the area of ​​the liquid-contacting part is made of a corrosion-resistant material.

[0326] In FIG. 12, the purification device 1200 has a filtration device in which a filter A and a filter BD are arranged in series in this order between the inlet and outlet (for example, the first embodiment of the filtration device). Alternatively, the purification device 1200 may have a filtration device in which a filter BU and a filter A are arranged in series in this order between the inlet and outlet (for example, the second embodiment), or a filtration device in which a filter BU, a filter A, and a filter BD are arranged in series in this order between the inlet and outlet (for example, a modified example of the second embodiment).

[0327] Furthermore, the purification device may have a return flow passage formed on flow path S12 formed by second inlet section 1201, distiller 1203, second outlet section 1202, inlet section 101, filter 103, piping 105, filter 104, and outlet section 102, which can return the purified liquid from the downstream side of filter 103 (filter A) to the upstream side of filter 103 (filter A) on flow path S12. The form of the return flow passage is not particularly limited, but may be the same as that described in the fifth embodiment of the filtration device. The form of the return flow passage may also be the same as that described in the sixth embodiment of the filtration device.

[0328] The refining device according to this embodiment may also have a tank on the flow path S12 upstream and / or downstream of the filter 103. The shape of the tank is not particularly limited, and the same tanks as those already described can be used.

[0329] Second embodiment of the refining device 13 is a schematic diagram showing a second embodiment of the purification device. The purification device 1300 has a second inlet section 1301, a second outlet section 1302, and a distiller 1303 and a distiller 1304 arranged in series between the second inlet section 1301 and the second outlet section 1302. The second outlet section 1302 is connected to the inlet section 101 of the filtration device. As a result, in the purification device 1300, a flow path S13 is formed by the second inlet section 1301, the distiller 1303, the piping 1305, the distiller 1304, the second outlet section 1302, the inlet section 101, the filter 103 (filter A), the piping 105, the filter 104 (filter BD), and the outlet section 102. That is, in the purification apparatus according to this embodiment, the distiller includes a plurality of distillers connected in series. When the distiller includes three or more distillers connected in series, the final distiller is connected to the filtration device.

[0330] In the purification device 1300, the liquid to be purified that flows in from the second inlet 1301 is distilled in the distiller 1303, flows through the pipe 1305, and is introduced into the distiller 1304. Note that, although Figure 13 shows a configuration in which the distiller 1303 and the distiller 1304 are connected by the pipe 1305, the purification device according to this embodiment is not limited to the above, and may have a separate pipe that can return the condensed liquid from the distiller 1304 to the distiller 1303 again.

[0331] The purification device of this embodiment has two distillers, and by appropriately controlling the operating conditions of the two distillers, it is possible to purify the target compound (chemical liquid) to a higher purity even if the liquid to be purified contains two or more compounds with different boiling points.

[0332] In the purification device 1300, the latter distiller of the two distillers connected in series is connected to one inlet of the filtration device, but the purification device according to the embodiment of the present invention is not limited to this, and if the filtration device has multiple inlets, each inlet may be connected to a separate distillation device. In this case, if two or more distillers connected in series are considered to be one group, it is also possible to adopt a configuration in which each group is arranged in parallel in the circulation path of the entire purification device.

[0333] [Corrosion-resistant material] Next, the corrosion-resistant material will be described. In the filtering device and purifying device according to the embodiments of the present invention described so far, at least a part of the liquid-contacting portion is preferably formed of a corrosion-resistant material, more preferably 90% or more of the liquid-contacting portion is formed of a corrosion-resistant material, and even more preferably 99% or more of the liquid-contacting portion is formed of a corrosion-resistant material.

[0334] There are no particular restrictions on the state in which the liquid-contacting parts are made of a corrosion-resistant material, but typical examples include those in which each component (e.g., the tanks described above) is made of a corrosion-resistant material, and those in which each component has a base material and a coating layer disposed on the base material, and the coating layer is made of a corrosion-resistant material.

[0335] The corrosion-resistant material is a non-metallic material and an electropolished metallic material. Examples of the non-metallic material include, but are not limited to, polyethylene resin, polypropylene resin, polyethylene-polypropylene resin, tetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloroethylene-ethylene copolymer resin, vinylidene fluoride resin, trifluorochloroethylene copolymer resin, and vinyl fluoride resin.

[0336] The metallic material is not particularly limited, but examples thereof include metallic materials in which the total content of Cr and Ni exceeds 25 mass% relative to the total mass of the metallic material components, and more preferably 30 mass% or more. The upper limit of the total content of Cr and Ni in the metallic material is not particularly limited, but is generally preferably 90 mass% or less. Examples of metal materials include stainless steel and Ni-Cr alloys.

[0337] The stainless steel is not particularly limited, and known stainless steels can be used. Among them, an alloy containing 8% or more by mass of Ni is preferred, and an austenitic stainless steel containing 8% or more by mass of Ni is more preferred. Examples of austenitic stainless steel include SUS (Steel Use Stainless) 304 (Ni content 8% by mass, Cr content 18% by mass), SUS304L (Ni content 9% by mass, Cr content 18% by mass), SUS316 (Ni content 10% by mass, Cr content 16% by mass), and SUS316L (Ni content 12% by mass, Cr content 16% by mass).

[0338] The Ni-Cr alloy is not particularly limited, and any known Ni-Cr alloy can be used, with a NiCr alloy containing 40 to 75 mass % of Ni and 1 to 30 mass % of Cr being preferred. Examples of Ni-Cr alloys include Hastelloy (trade name, the same applies hereinafter), Monel (trade name, the same applies hereinafter), and Inconel (trade name, the same applies hereinafter), etc. More specific examples include Hastelloy C-276 (Ni content 63 mass%, Cr content 16 mass%), Hastelloy-C (Ni content 60 mass%, Cr content 17 mass%), Hastelloy C-22 (Ni content 61 mass%, Cr content 22 mass%), etc. Furthermore, the Ni-Cr alloy may further contain B, Si, W, Mo, Cu, Co, and the like in addition to the above alloy, if necessary.

[0339] The method for electrolytically polishing a metal material is not particularly limited, and any known method can be used, such as those described in paragraphs 0011 to 0014 of JP 2015-227501 A and paragraphs 0036 to 0042 of JP 2008-264929 A.

[0340] It is presumed that electrolytic polishing of a metal material causes the Cr content in the surface passive layer to be higher than the Cr content in the parent phase, and therefore, it is presumed that the use of a refining device whose liquid-contacting parts are formed from an electrolytically polished metal material makes it difficult for metal impurities containing metal atoms to leak into the liquid to be purified. The metal material may be buffed. The buffing method is not particularly limited, and known methods can be used. The size of the abrasive grains used for the buffing finish is not particularly limited, but #400 or smaller is preferred, as this tends to reduce the surface irregularities of the metal material. The buffing is preferably performed before electrolytic polishing.

[0341] [Chemical solution] The chemical solution produced using the above-described filtering device is preferably used in the manufacture of semiconductor substrates, and more preferably used for forming fine patterns with a node of 10 nm or less (for example, a process including pattern formation using EUV). In other words, the above-mentioned filtration apparatus is preferably used for producing chemical solutions for use in manufacturing semiconductor substrates, and more specifically, for producing chemical solutions used to treat inorganic and / or organic substances after the completion of each step or before moving to the next step in the manufacturing process of semiconductor devices, which includes a lithography step, an etching step, an ion implantation step, a peeling step, etc. Specifically, the filtration device is preferably used for producing at least one chemical liquid (chemical liquid obtained by purifying an organic liquid to be purified) selected from the group consisting of a developer, a rinse liquid, a wafer cleaning liquid, a line cleaning liquid, a pre-wet liquid, a wafer rinse liquid, a resist liquid, a liquid for forming an underlayer film, a liquid for forming an upper layer film, and a liquid for forming a hard coat.In other forms, the filtration device is preferably used for producing at least one chemical liquid (chemical liquid obtained by purifying an aqueous liquid to be purified) selected from the group consisting of a water-based aqueous developer, an aqueous rinse liquid, a stripping liquid, a remover, an etching liquid, an acidic cleaning liquid, phosphoric acid, and a phosphoric acid-hydrogen peroxide mixture (SPM: Sulfuric acid-Hydrogen Peroxide Mixture).

[0342] The above-mentioned filtering device can also be used to produce chemical solutions used to rinse the edge lines of semiconductor substrates before and after resist coating. The above-mentioned filtering device can also be used to produce a dilution liquid for the resin contained in the resist solution and a solvent contained in the resist solution.

[0343] In addition, the above-mentioned filtration device can also be used to produce chemical solutions used for purposes other than the production of semiconductor substrates, such as developers for polyimide, sensor resists, lens resists, etc., and rinse solutions. The filtration device can also be used to produce solvents for medical or cleaning applications, particularly for producing chemical solutions used to clean containers, pipes, and substrates (e.g., wafers, glass, etc.). In particular, the filtering device is preferably used for producing at least one selected from the group consisting of a pre-wet liquid, a developer, and a rinse liquid in pattern formation using EUV (extreme ultraviolet).

[0344] [Medicinal solution container] The chemical solution produced by the filtration device may be stored in a container until use. Such a container and the chemical solution stored in the container are collectively referred to as a chemical solution container. The chemical solution is taken out of the stored chemical solution container and used.

[0345] The container for storing the chemical solution is preferably one for manufacturing semiconductor substrates, which has a high degree of cleanliness inside and is less likely to leach impurities into the chemical solution during storage. Usable containers are not particularly limited, but examples include the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited to these.

[0346] As the container, it is also preferable to use a multi-layer bottle whose inner wall has a six-layer structure made of six types of resin, or a multi-layer bottle whose inner wall has a seven-layer structure made of six types of resin, in order to prevent impurities from being mixed in (contaminated) with the drug solution. Examples of such containers include the container described in JP 2015-123351 A.

[0347] At least a part of the liquid-contacting portion of the container is preferably made of the corrosion-resistant material already described. In order to obtain a more excellent effect of the present invention, it is preferable that 90% or more of the area of ​​the liquid-contacting portion is made of the above material. [Example]

[0348] The present invention will be described in more detail below with reference to examples. The material components, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0349] In addition, when preparing the chemical solutions in the Examples and Comparative Examples, handling of containers, preparation of the chemical solutions, filling, storage, and analytical measurements were all carried out in clean rooms meeting ISO Class 2 or 1 standards. To improve measurement accuracy, when measuring the content of organic impurities and the content of metal atoms that are below the detection limit in normal measurements, the chemical solutions were concentrated to 1 / 100th their volume and the content was calculated by converting it to the concentration of the solution before concentration. Note that the surfaces of the equipment, filters, containers, and other tools used for purification that came into contact with the chemical solutions were thoroughly washed with chemical solutions that had been purified using the same method before use.

[0350] [Test Example 1: Purification of organic liquid to be purified and performance evaluation of chemical liquid] Chemical solution 1 was produced using the purification apparatus shown in Figure 14. The purification apparatus in Figure 14 has a filtration device in which filter BU-1, tank TU-1, filter BU-2, filter FA, filter BD-1, tank TD-1, and filter BD-2 are connected in series between an inlet and an outlet, and a distiller (a two-stage distiller consisting of D1 and D2, referred to as a "two-stage distiller" in the table below) connected upstream of the filtration device. Each unit forms a flow path S-14 together with piping, and a return flow path R-14 is formed in flow path S-14, allowing the purified liquid to be returned from the downstream side (tank TD-1) of filter FA (filter FA corresponds to filter A already described) to the upstream side of filter FA. The table shows the material components and pore size of each filter used in producing Chemical Solution 1. Each filter was used after immersing in PGMEA for one day.

[0351] The abbreviations for the material components of each filter in the table are as follows:

[0352] 1x Filter Porous membranes containing polyimide resins with different imidization rates were prepared with reference to the description in paragraphs 0133 to 0139 of JP 2016-155121 A. Specifically, the pore size was controlled by adjusting the particle size of the fine particles used, and the imidization rate was controlled by adjusting the treatment temperature, treatment time, pH, baking temperature and / or re-baking temperature in the chemical etching step. The pore size and imidization rate of filter X1 are shown in the table.

[0353] Filter X2 to Filter X8 and Filter 2 Filters X2 to X8 and Filter 2 were produced in the same manner as Filter 1, except that the particle size of the microparticles and the conditions for chemical etching were adjusted so that the pore size and imidization rate would be as shown in the table. The pore size and imidization rate of each filter are as shown in the table.

[0354] Filter Y1 A porous membrane containing a polyimide resin was produced with reference to the description in paragraphs 0223 and 0234-0239 of JP 2017-68262 A. The pore size and imidization rate are shown in the table. The pore size was controlled by adjusting the particle size of the fine particles used, and the imidization rate was controlled by adjusting the baking temperature and / or rebaking temperature. The pore size and imidization rate of filter Y1 are shown in the table.

[0355] Filter Y2 to Filter Y6 Filters Y2 to Y6 were produced in the same manner as Filter 1, except that the particle size of the microparticles used, and the baking temperature and / or re-baking temperature were adjusted so that the pore size and imidization rate would be as shown in the table. The pore size and imidization rate of each filter are as shown in the table.

[0356] Filter R A filter R, which is a porous membrane containing a polyimide resin, was manufactured with reference to the description in paragraphs 0019 to 0027 of JP-A 2016-538122. The manufactured porous membrane is the one described as "Example 2d" in the table in paragraph 0019 of JP-A 2016-538122. The porous membrane had a structure in which the imidization rate varied in the thickness direction, but the imidization rate was calculated as an average value for the entire porous membrane. The pore size and imidization rate are shown in the table.

[0357] Filter S Filter S, a porous membrane containing a polyimide resin, was manufactured with reference to the description in paragraphs 202 and 203 of JP 2018-20301 A. The manufactured porous membrane is the one described in Example 1 of JP 2018-20301 A. The pore size, B value, and imidization ratio are shown in the table below.

[0358] Filter T Filter T, a porous membrane containing a polyimide resin, was manufactured with reference to the description in paragraphs 202 and 203 of JP 2018-20301 A. The manufactured porous membrane is the one described in Example 2 of JP 2018-20301 A. The pore size, B value, and imidization ratio are shown in the table.

[0359] PP: Polypropylene IEX: A filter obtained by introducing ion exchange groups consisting of sulfonic acid groups into a polyethylene substrate. Nylon: Nylon UPE: Ultra-high molecular weight polyethylene PTFE: Polytetrafluoroethylene

[0360] The abbreviations for the purified liquids in the table are as follows: PGMEA: Propylene glycol monomethyl ether acetate PGMEA / PGME (7:3): A 7:3 (volume basis) mixture of PGMEA and PGME nBA: Butyl acetate PC / PGMEA (1:9): A 1:9 (volume basis) mixture of PC and PGMEA PGME: Propylene glycol monoethyl ether ·MIBC: 4-methyl-2-pentanol CHN: Cyclohexanone ·iAA: Isoamyl acetate

[0361] The liquid to be purified was a commercially available high-purity grade "PGMEA," which was purchased and purified using the above-mentioned purification device. During purification, the return flow path R-14 was used, and the liquid was circulated and filtered three times for each return flow path to obtain chemical solution 1.

[0362] [Production of chemical solutions 2 to 92] The purification equipment (or filtration equipment) listed in the table was used to purify each of the target substances listed in the table to obtain a chemical solution. Note that each purification equipment (or filtration equipment) is shown in Figures 15 to 30. The material components and pore sizes of filters FA, BU-1 to BU-4, and BD-1 to BD-2 are as shown in the table. Note that the filtration equipment used in purifying the target liquid had a return flow passage indicated by R- (number), and for those with "Yes" in the "Circulation" column in the table, circulation filtration was performed three times for each return flow passage. The table also lists the SP value of each purified liquid. In the table, "-" indicates that the filter was not used, and this also applies to other tables in this specification.

[0363] <Pre-cleaning the filter> The "Filter Pre-Cleaning" column in the table lists the pre-cleaning conditions for each filter. "PGMEA 1-day immersion" indicates that the filter was used after immersing in high-purity grade PGMEA for one day. A "-" in the same column indicates that the filter was not pre-cleaned. Furthermore, "Specific cleaning solution 1 (10h immersion)" indicates that the filter was used after immersion for 10 hours in specific cleaning solution 1 described below. "Specific cleaning solution 2 (20h immersion)" indicates that the filter was used after immersion for 20 hours in specific cleaning solution 2 described below. "Specific cleaning solution 3 (10h immersion)" indicates that the filter was used after immersion for 10 hours in specific cleaning solution 3 described below. "Specific cleaning solution 4 (20h immersion)" indicates that the filter was used after immersion for 20 hours in specific cleaning solution 4 described below. "Specific cleaning solution 5 (10h immersion)" indicates that the filter was used after immersion for 10 hours in specific cleaning solution 5 described below.

[0364] (Specific cleaning solution) Specific cleaning solution 1: dimethylacetamide / butyl acetate (volume ratio) 60 / 40 Specific cleaning solution 2: Dimethylacetamide / Cyclohexanone / Propylene glycol monomethyl ether (volume ratio) 60 / 30 / 10 Specific cleaning solution 3: dimethylformamide / ethyl lactate (volume-based mixture ratio) 60 / 40 Specific cleaning solution 4: N-methylpyrrolidone / cyclohexanone (volume-based mixture ratio) 70 / 30 Specific cleaning solution 5: Dimethylacetamide / 2-heptanone (volume-based mixture ratio) 70 / 30

[0365] [Evaluation 1: Evaluation of chemical residue defect suppression performance and stain defect suppression performance] Chemical solution 1 was spin-coated onto a silicon wafer (Bare-Si) having a diameter of approximately 300 mm to obtain a chemical solution-coated wafer. The apparatus used was a Lithius ProZ, and the coating conditions were as follows:

[0366] Amount of solution used: 2ml each Silicon wafer rotation speed during application: 2,200 rpm, 60 seconds

[0367] Next, using KLA-Tencor's wafer inspection system "SP-5" and Applied Materials' fully automated defect review and classification system "SEMVision G6," the number of defects 19 nm or larger in size present on the entire surface of the wafer and their composition were investigated. The total number of defects measured by SP-5 was counted as the number of residual defects, and shape observation was performed by G6, and defects that were not particulate (stain-like) were counted as stain-like defects. The results were evaluated according to the following criteria and shown in the table. The fewer the number of defects present on the wafer, the better the defect suppression performance of the chemical. In the following evaluation, the "number of defects" refers to the number of residue defects and the number of stain-like defects, respectively. Chemicals 2 to 92 were also evaluated using the same method as above. The results are shown in the table.

[0368] AA Defect count was 30 or less per wafer. A The number of defects was more than 30 / wafer but less than 50 / wafer. B The number of defects was greater than 50 / wafer but less than 100 / wafer. C The number of defects was greater than 100 / wafer but less than 200 / wafer. D The number of defects was greater than 200 / wafer and less than 500 / wafer. E The number of defects exceeds 500 per wafer.

[0369] [Evaluation 2: Bridge defect prevention performance] The performance of the chemicals in suppressing bridge defects was evaluated using Chemical 1 as a pre-wet liquid. First, the resist resin composition used will be described.

[0370] Resist resin composition 1 Resist resin composition 1 was obtained by mixing the following components.

[0371] Acid-decomposable resin (resin represented by the following formula (weight average molecular weight (Mw) 7500): the numerical value shown for each repeating unit means mol %): 100 parts by mass

[0372] [ka]

[0373] Photoacid generator shown below: 8 parts by mass

[0374] [ka]

[0375] The quencher shown below: 5 parts by mass (the mass ratio, from left to right, was 0.1:0.3:0.3:0.2). Of the quenchers listed below, the polymer type has a weight-average molecular weight (Mw) of 5,000. The numerical values ​​listed for each repeating unit indicate the molar ratio.

[0376] [ka]

[0377] Hydrophobic resin shown below: 4 parts by mass (mass ratio of (1):(2) = 0.5:0.5). Of the hydrophobic resins shown below, the hydrophobic resin of formula (1) has a weight average molecular weight (Mw) of 7000, and the hydrophobic resin of formula (2) has a weight average molecular weight (Mw) of 8000. In each hydrophobic resin, the numerical value written for each repeating unit means the molar ratio.

[0378] [ka]

[0379] solvent: PGMEA (propylene glycol monomethyl ether acetate): 3 parts by mass Cyclohexanone: 600 parts by mass γ-BL (γ-butyrolactone): 100 parts by mass

[0380] Testing Method The test method is explained below. First, a silicon wafer of approximately 300 mm was pre-wetted with Chemical Solution 1, and then the resist resin composition was spin-coated onto the pre-wetted silicon wafer. After that, the wafer was dried by heating on a hot plate at 150°C for 90 seconds to form a resist film with a thickness of 9 μm. This resist film was subjected to pattern exposure using an ArF excimer laser scanner (ASML, PAS5500 / 850C, wavelength 248 nm) under exposure conditions of NA=0.60 and σ=0.75, via a mask having a line and space pattern such that the pattern formed after reduced projection exposure and development would have a line width of 30 nm and a space width of 30 nm. After exposure, the film was baked at 120°C for 60 seconds, developed, rinsed, and baked at 110°C for 60 seconds to form a resist pattern with a line width of 30 nm and a space width of 30 nm.

[0381] For the above resist pattern, 100 shots of the pattern were obtained using a critical dimension SEM (CG4600, Hitachi-HighTech), and the number of bridge-like defects between patterns (bridge defects) was counted to determine the number of defects per unit area. The results were evaluated according to the following criteria and shown in the table. The fewer the number of bridge-like defects between patterns, the better the chemical solution's ability to suppress bridge defects.

[0382] For chemical solutions 2 to 92, those with "Pre-wet" in the "Evaluation method" column of the table were evaluated for bridge defect suppression performance in the same manner as for chemical solution 1. For those with "Developer" in the "Evaluation method" column of the table, the bridge defect suppression performance was evaluated in the same manner as for chemical solution 1, except that the pre-wet described in the evaluation procedure for chemical solution 1 was not performed and the chemical solution described in the table was used as the developer. For those with "Rinse" in the "Evaluation method" column of the table, the bridge defect suppression performance was evaluated in the same manner as for chemical solution 1, except that the pre-wet described in the evaluation procedure for chemical solution 1 was not performed and the chemical solution described in the table was used as the rinse. The results for each are shown in the table.

[0383] AA Bridge defect count: 1 / cm 2It was less than. A Number of bridge defects: 1 / cm 2 More than 2 pieces / cm 2 It was less than. B: Number of bridge defects: 2 / cm 2 More than 5 pieces / cm 2 It was less than. C Number of bridge defects: 5 / cm 2 More than 10 pieces / cm 2 It was less than. D Number of bridge defects: 10 / cm 2 More than 15 pieces / cm 2 It was less than. E Number of bridge defects: 15 / cm 2 That was all.

[0384] [Evaluation 3: Pattern width uniformity] For the above resist pattern, 100 shots of the pattern were obtained using a length measurement SEM (CG4600, Hitach-HighTech), and the absolute value of the difference between the average LWR (Line Width Roughness) and the maximum (or minimum) line width was calculated. The results were evaluated according to the following criteria and shown in the table. The smaller the "absolute value of the difference," the better the uniformity of the pattern width of the chemical. The "absolute value of the difference between the average LWR and the maximum (minimum) line width" means that the evaluation was based on the larger absolute value of the difference between the average LWR and the maximum line width, or the difference between the average LWR and the minimum line width.

[0385] The absolute value of the difference between the average and maximum (minimum) AA line width was less than 2% of the average. A The absolute value of the difference between the average line width and the maximum (minimum) was 2% or more but less than 5% of the average. B The absolute value of the difference between the average line width and the maximum (minimum) was 5% or more but less than 10% of the average. C The absolute value of the difference between the average line width and the maximum (minimum) was 10% or more but less than 20% of the average line width. D The absolute value of the difference between the average line width and the maximum (minimum) was 20% or more of the average. E Shots were included where line width could not be measured.

[0386] [Evaluation 4: Filter life evaluation] The liquid to be purified was continuously purified using each purification device (or filtration device) listed in the table. After the liquid to be purified was passed through the purification device (or filtration device) and the condition of the device stabilized, the resulting chemical solution was immediately collected for testing (initial sample). Subsequently, the chemical solution obtained after purification every 10,000 kg of liquid passed through was collected for testing (aged sample). The chemical solution collected for testing was evaluated using the method for evaluating the residual defect suppression performance of the chemical solution described in "Evaluation 1." The number of defects per unit area was compared with the initial sample, and the amount of liquid passed through when the number of defects in the aged sample doubled was defined as the "lifespan" of the filter. The lifespan when using the filtration device shown in Figure 24 was defined as 1, and the filter lifespan of each device was evaluated as a ratio. The results were evaluated according to the following criteria and are shown in the table. The device shown in Figure 24 was labeled "reference" in the evaluation results.

[0387] AA lifespan was more than 10 times longer. A The lifespan was more than 5 times but less than 10 times. B. The lifespan was more than twice as long but less than five times as long. C The lifespan was more than 1x but less than 2x. D The lifespan was less than 1x.

[0388] [Test Example 2: Purification of aqueous solution to be purified and performance evaluation of chemical solution]

[0389] [Production of chemical solutions 201 and 202] The liquid to be purified was purchased and prepared: SPM (Sulfuric acid-Hydrogen Peroxide Mixture) and an aqueous phosphoric acid solution (phosphoric acid content 85% by mass). SPM is a 4:1 mixture (by volume) of sulfuric acid and hydrogen peroxide. Next, chemical solutions 201, 201 were produced using the filtration device shown in Figure 20. The filtration device in Figure 20 is a filtration device in which filter BU-1, tank TU-1, filter BU-2, filter FA, filter BD-1, tank TD-1, and filter BD-2 are connected in series between an inlet and an outlet, forming a flow path S-20. The filtration device shown in Figure 20 also has a return flow path R-20 that can return the liquid to be purified from the downstream side of filter BD-1 to the upstream side of filter FA, and the liquid to be purified was circulated and filtered three times. The material components and pore sizes of each filter in the filtration device of FIG. 20 are shown in the table below. The abbreviations for the material components of the filters in the table are the same as those described above, and the explanations will be omitted.

[0390] [Production of chemical solutions 203 and 204] Chemical solutions 203 and 204 were produced in the same manner as chemical solutions 201 and 202, except that the filtering device shown in FIG. 25 (having a filter FA and having a flow path S-25 formed therein) was used instead of the filtering device shown in FIG. 20. The material components of filter FA are shown in the table. Note that no circulating filtration was performed when producing the above chemical solutions.

[0391] [Evaluation 1: Evaluation of the defect suppression performance of the chemical (particle defects, stain-like defects)] A bare silicon wafer with a diameter of approximately 300 mm was prepared, and while the wafer was rotated at 500 rpm, 100 ml of each chemical solution was dispensed at a rate of 5 ml / s over 20 seconds. The wafer was then rotated at 2000 rpm for 30 seconds for a spin-dry process. This was used as the evaluation wafer. Next, the number of defects 26 nm or larger in size present on the entire surface of the wafer and their composition were investigated using a KLA-Tencor wafer inspection system "SP-5" and an Applied Materials fully automated defect review and classification system "SEMVision G6." Of the defects measured, particulate foreign matter was counted as particle defects, and anything other than the above was counted as stain defects, and they were evaluated according to the following criteria. The results are shown in the "Particle defect suppression performance" and "Stain defect suppression performance" columns in the table. Note that the number of defects refers to the number of particle defects and the number of stain defects, respectively.

[0392] A The number of defects was less than 50 per wafer. B: The number of defects was greater than 50 / wafer and less than 300 / wafer. C The number of defects exceeds 300 per wafer.

[0393] [Evaluation 2: Filter life evaluation] The liquid to be purified was continuously purified using each filtration device listed in the table. After the liquid to be purified was passed through the filtration device and the condition of the filtration device stabilized, the resulting chemical solution was immediately collected for testing (initial sample). Subsequently, the chemical solution obtained after purification every 10,000 kg of liquid passed was collected for testing (aged sample). The chemical solutions collected for testing were evaluated using the evaluation method for particle defect suppression performance of chemical solutions described in "Evaluation 1." The number of defects per unit area was compared with that of the initial sample, and the amount of liquid passed when the number of defects in the aged sample doubled was defined as the "lifespan" of the filter. The lifespan of the filter when using the filtration device shown in Figure 25 (chemical solution 203) was set to 1, and the lifespan of the filter for each device was evaluated as a ratio. The results were evaluated according to the following criteria and are shown in the table. Note that the evaluation column for chemical solution 203 indicates the result as "standard."

[0394] A The lifespan was more than 10 times longer. B. The lifespan was more than 5 times but less than 10 times. C The lifespan was more than 1x but less than 5x. D The lifespan was less than 1x.

[0395] Test Example 3: Production of a chemical solution that is a resist resin composition and performance evaluation of the chemical solution

[0396] [Production of Chemical Solution 301] Resist resin composition 2 containing the following components was prepared as a liquid to be purified.

[0397] Resin A-2 synthesized by the following method: 0.79 g

[0398] <Resin (A-2)> Synthesis of Resin (A-2) A 2-L flask was charged with 600 g of cyclohexanone and purged with nitrogen at a flow rate of 100 mL / min for one hour. Then, 0.02 mol of polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd.) was added, and the internal temperature was raised to 80°C. Next, the following monomers 1 to 3 and 0.02 mol of polymerization initiator V-601 (Wako Pure Chemical Industries, Ltd.) were dissolved in 200 g of cyclohexanone to prepare a monomer solution. The monomer solution was added dropwise to the flask heated to 80°C over 6 hours. After the dropwise addition, the mixture was allowed to react at 80°C for an additional 2 hours. Monomer 1: 0.3 mol Monomer 2: 0.6 mol Monomer 3: 0.1 mol

[0399] [ka]

[0400] The reaction solution was cooled to room temperature and added dropwise to 3 L of hexane to precipitate a polymer. The filtered solid was dissolved in 500 mL of acetone and added dropwise again to 3 L of hexane. The filtered solid was dried under reduced pressure to obtain a copolymer (A-2) of Monomers 1 to 3.

[0401] A reaction vessel was charged with 10 g of the polymer obtained above, 40 mL of methanol, 200 mL of 1-methoxy-2-propanol, and 1.5 mL of concentrated hydrochloric acid, and the mixture was heated to 80°C and stirred for 5 hours. The reaction solution was allowed to cool to room temperature and added dropwise to 3 L of distilled water. The filtered solid was dissolved in 200 mL of acetone and added dropwise again to 3 L of distilled water. The filtered solid was dried under reduced pressure to obtain Resin (A-2) (8.5 g). The weight-average molecular weight (Mw) measured by gel permeation chromatography (GPC) (solvent: THF (tetrahydrofuran)) in terms of standard polystyrene was 12,300, and the molecular weight dispersity (Mw / Mn) was 1.51. The resin composition (molar ratio) is: 1 The weight average molecular weight (Mw: polystyrene equivalent) and dispersity (Mw / Mn) of the resin were calculated by GPC (solvent: THF) measurement.

[0402] [ka]

[0403] The composition of Resin A-2 was 30 / 60 / 10 (molar ratio) of the structural units listed above, from left to right. The weight average molecular weight (Mw) was 12,300, and the Mw / Mn ratio was 1.51.

[0404] Acid generator (B-2) shown below: 0.18 g [ka]

[0405] The following basic compound (E-1): 0.03 g [ka]

[0406] Propylene glycol monomethyl ether acetate: 45g Propylene glycol monomethyl ether: 30g

[0407] Chemical solution 301 was produced using the filtration device shown in Figure 26. In the filtration device of Figure 26, filter BU-1, tank TU-1, filter FA, and filter BD-1 are connected in series between the inlet and outlet. Each unit forms a flow path S-26 together with piping. In addition, a return flow path R-26 is formed from the downstream side of filter BD-1 to the downstream side of filter BU-1 but upstream side of tank TA-1, allowing the liquid to be purified to be returned. The liquid to be purified was returned via return flow path R-26 and circulated and filtered three times. The table below shows the material components and pore size of each filter used in the purification.

[0408] [Production of chemical solutions 302, 303, 310, and 311] Except for using the filtration devices shown in the table, chemical solutions 302 and 303, as well as chemical solutions 310 and 311, were produced in the same manner as chemical solution 301. Note that in the production of chemical solution 303, circulating filtration was not performed.

[0409] [Production of chemical solution 304] As a liquid to be purified, a resist resin composition 3 containing the following components was prepared.

[0410] Resin A-14 synthesized by the following method: 0.785g

[0411] <Resin (A-14)> Synthesis of Resin (A-14) Resin (A-14) having the following structure was obtained in the same manner as in the synthesis of Resin (A-2) above, except that the monomer used was changed. [ka]

[0412] Resin A-14 had a composition in which the structural units were arranged in a molar ratio of 20 / 40 / 40 from left to right. The weight-average molecular weight (Mw) was 11,000, and the Mw / Mn ratio was 1.45.

[0413] Acid generator (B-9) shown below: 0.18g [ka]

[0414] The following basic compound (E-2): 0.03 g [ka]

[0415] Propylene glycol monomethyl ether acetate: 45g Cyclohexanone: 30g

[0416] 0.005g of the following hydrophobic resin (3b): [ka]

[0417] Chemical solution 304 was produced using the filtration device shown in Figure 26. In the filtration device of Figure 26, filter BU-1, tank TU-1, filter FA, and filter BD-1 are connected in series between the inlet and outlet. Each unit forms a flow path S-26 together with piping. In addition, a return flow path R-26 is formed from the downstream side of filter BD-1 to the downstream side of filter BU-1 but upstream side of tank TU-1, allowing the purified liquid to be returned. The purified liquid was returned via return flow path R-26 and circulated and filtered three times. The table shows the material components and pore size of each filter used in the purification.

[0418] [Production of chemical solutions 305, 306, 312, and 313] Except for using the filtration devices shown in the table, chemical solutions 305 and 306, as well as chemical solutions 312 and 313, were produced in the same manner as chemical solution 304. Note that in the production of chemical solution 206, circulating filtration was not performed.

[0419] [Production of Chemical Solution 307] Resist resin composition 4 containing the following components was prepared as a liquid to be purified.

[0420] Resist resin composition 4 containing the following components was prepared as a liquid to be purified.

[0421] Resin (A-1)-3 synthesized by the following method: 97% by mass

[0422] <Resin (A-1)-3> Resin (A-1)-3 was synthesized with reference to the description in paragraphs 0131 to 0134 of JP 2009-265609 A. The repeating units of Resin (A-1)-3 were as shown in the following formula, and their composition (molar ratio) was 50 / 40 / 10 from left to right. The weight-average molecular weight was 20,000, and the polydispersity expressed as Mw / Mn was 1.57. (A-1)-3 [ka]

[0423] Acid generator (B-35) shown below: 2.5% by mass [ka]

[0424] C-1 Dicyclohexylmethylamine: 0.4% by mass

[0425] D-1 Fluorine-based surfactant, Megafac F-176 (manufactured by Dainippon Ink and Chemicals, Inc.): 0.1% by mass Here, the contents of (A-1)-3 to D-1 above indicate the contents based on mass in the solid content of the resist resin composition 4.

[0426] ·solvent Propylene glycol monomethyl ether acetate: 80% by mass Propylene glycol monomethyl ether: 20% by mass The solvent content above indicates the content of each solvent (each content when the total mass of the solvents is taken as 100% by mass) in the solvent contained in resist resin composition 4. The solid content of resist resin composition 4 was adjusted to 10% by mass.

[0427] Chemical solution 307 was produced using the filtration device shown in Figure 26. In the filtration device of Figure 26, filter BU-1, tank TU-1, filter FA, and filter BD-1 are connected in series between the inlet and outlet. Each unit forms a flow path S-26 together with piping. In addition, a return flow path R-26 is formed from the downstream side of filter BD-1 to the downstream side of filter BU-1 but upstream side of tank TU-1, allowing the liquid to be purified to be returned. The liquid to be purified was returned via return flow path R-26 and circulated and filtered three times. The table shows the material components and pore size of each filter used in the purification.

[0428] [Production of Chemical Solution 308 and Chemical Solution 309] Chemical solutions 308 and 309 were produced in the same manner as chemical solution 307, except that the filtration devices shown in the table were used. Note that in the production of chemical solution 309, circulating filtration was not performed.

[0429] [Evaluation of chemical defect suppression performance: Defect suppression performance during EUV exposure] Using the chemical solutions 301 to 303 and the chemical solutions 310 to 311, the defect suppression performance (post-development defect suppression performance and bridge defect suppression performance) of the chemical solutions was evaluated by the following procedure. Note that EUV exposure refers to a pattern formation method using exposure using EUV.

[0430] Chemical solutions 301 to 303 and chemical solutions 310 to 311 were applied onto a 12-inch silicon wafer, and baked at 120° C. for 60 seconds to form a resist film with a thickness of 40 nm.

[0431] (Exposure conditions for post-development defect performance evaluation) The wafer prepared above was exposed to EUV light using a 0.25 NA (numerical aperture) and dipole illumination (60x dipole, outer sigma 0.81, inner sigma 0.43). Specifically, the exposure dose was 1 mJ / cm for the negative resist. 2 The entire surface was exposed to light without using a mask.

[0432] (Exposure conditions for bridge defect suppression performance evaluation) The wafer prepared above was subjected to EUV exposure using an NA (Numerical Aperture) of 0.25 and Quasar illumination (Quasar45, outer sigma 0.81, inner sigma 0.51). Specifically, the entire wafer was exposed to EUV light through a mask containing a pattern for forming a contact hole pattern with wafer dimensions of 60 nm pitch and 30 nm hole size (for evaluating C / H releasability), and an LS (line and space) pattern with a line width of 22 nm and a pitch of 50 nm, with the exposure dose adjusted to result in a line width of 22 nm.

[0433] (Developing conditions) After exposure under the above conditions, the film was immediately baked at 100° C. for 60 seconds. Thereafter, using a shower-type developing device (ADE3000S manufactured by ACTES Co., Ltd.), the wafer was developed by spraying the developer (23°C) at a flow rate of 200 mL / min for 30 seconds while rotating the wafer at 50 rpm, thereby obtaining a sample for evaluation.

[0434] (Evaluation 1: Evaluation of bridge defect suppression performance) The resolution of the exposed LS pattern was observed using a scanning electron microscope (CG4600, manufactured by Hitachi, Ltd.) at a magnification of 200k in n = 300 fields of view, and the number of LS pattern bridges that occurred within each observed field of view was evaluated and recorded as the number of bridge defects in the LS pattern. The smaller this number, the better the chemical's ability to suppress bridge defects. The results were evaluated according to the following criteria and are shown in the table.

[0435] AA: The number of defects was 10 or less (per field of view). A: The number of defects was more than 10 (pieces / viewpoint) and less than 30 (pieces / viewpoint). B: The number of defects was more than 30 (pieces / viewpoint) and less than 100 (pieces / viewpoint). C: The number of defects was more than 100 (pieces / viewpoint) and less than 300 (pieces / viewpoint). D: The number of defects exceeded 300 (per field of view).

[0436] (Evaluation 2: Evaluation of post-development defect suppression performance) The total number of defects of 19 nm or larger on the entire surface of the wafer was counted using the KLA-Tencor wafer inspection system "SP-5." The results were evaluated according to the following criteria and are shown in the table.

[0437] A: The number of defects was less than 200 per wafer. B: The number of defects was more than 200 / wafer and less than 500 / wafer. C: The number of defects was more than 500 / wafer and less than 1000 / wafer. D: The number of defects was more than 1,000 / wafer but less than 1,500 / wafer. E: The number of defects exceeded 1,500 per wafer.

[0438] [Evaluation of defect suppression performance of chemicals: Defect suppression performance during ArF exposure] Using the chemical solutions 304 to 306 and the chemical solutions 312 to 313, the defect suppression performance (post-development defect suppression performance and bridge defect suppression performance) of the chemical solutions was evaluated by the following procedure. Note that ArF exposure refers to a pattern formation method using exposure with an ArF excimer laser.

[0439] Chemical solutions 304 to 306 and chemical solutions 312 to 313 were applied onto a 12-inch silicon wafer, and baked at 90 to 120° C. for 60 seconds to form a resist film with a thickness of 40 nm. Before applying the resist film, an organic anti-reflective film ARC29SR (manufactured by Brewer) was applied to the silicon wafer and baked at 205° C. for 60 seconds to form an anti-reflective film with a thickness of 86 nm.

[0440] (Exposure conditions for post-development defect performance evaluation) The wafer prepared above was exposed to ArF light using an ArF excimer laser immersion scanner (ASML XT1700i, NA 1.20, Dipole, outer sigma 0.900, inner sigma 0.700, Y deflection). Specifically, for the negative resist, 1 mJ / cm was used. 2 The entire surface was exposed to light without using a mask.

[0441] (Exposure conditions for bridge defect suppression performance evaluation) The resulting wafer was subjected to pattern exposure using an ArF excimer laser immersion scanner (ASML XT1700i, NA 1.20, Dipole, outer sigma 0.900, inner sigma 0.700, Y deflection). A 6% halftone mask with a line size of 50 nm and a line:space ratio of 1:1 was used as the reticle. Ultrapure water was used as the immersion liquid. The conditions were adjusted so that the resulting pattern was a line and space pattern with a pitch of 100 nm, a space width of 35 nm, and a line width of 65 nm.

[0442] (Developing conditions) After baking at 100°C (Post Exposure Bake; PEB), the wafer was developed by puddling in a developer for 30 seconds to produce a patterned wafer. When a rinse treatment was performed, the wafer was developed by puddling in a developer for 30 seconds, and then rinsed with a rinse solution before drying. The wafer was then rotated at 4000 rpm for 30 seconds to obtain a sample for evaluation.

[0443] (Evaluation 1: Evaluation of bridge defect suppression performance) The resolution of the exposed LS pattern was observed using a scanning electron microscope (CG4600, manufactured by Hitachi, Ltd.) at a magnification of 200k in n = 300 fields of view, and the number of LS pattern bridges that occurred within each observed field of view was evaluated and recorded as the number of bridge defects in the LS pattern. The smaller this number, the better the chemical's ability to suppress bridge defects. The results were evaluated according to the following criteria and are shown in the table.

[0444] AA: The number of defects was 10 or less (per field of view). A: The number of defects was more than 10 (pieces / viewpoint) and less than 30 (pieces / viewpoint). B: The number of defects was more than 30 (pieces / viewpoint) and less than 100 (pieces / viewpoint). C: The number of defects was more than 100 (pieces / viewpoint) and less than 300 (pieces / viewpoint). D: The number of defects exceeded 300 (per field of view).

[0445] (Evaluation 2: Evaluation of post-development defect suppression performance) The total number of defects of 19 nm or larger on the entire surface of the wafer was counted using the KLA-Tencor wafer inspection system "SP-5." The results were evaluated according to the following criteria and are shown in the table.

[0446] A: The number of defects was less than 200 per wafer. B: The number of defects was more than 200 / wafer and less than 500 / wafer. C: The number of defects was more than 500 / wafer and less than 1000 / wafer. D: The number of defects was more than 1,000 / wafer but less than 1,500 / wafer. E: The number of defects exceeded 1,500 per wafer.

[0447] [Evaluation of defect suppression performance of chemicals: Defect suppression performance during KrF exposure] Using chemical solutions 307 to 309, the defect suppression performance (post-development defect suppression performance and bridge defect suppression performance) of the chemical solutions was evaluated by the following procedure. Note that KrF represents a pattern formation method by exposure using a KrF excimer laser.

[0448] The silicon wafer was treated with HMDS (hexamethyldisilazane) (110°C for 35 seconds), and a resist film was formed to a thickness of 100 nm using chemical solutions 307 to 309. Before applying the chemical solutions, a 100 nm oxide film was formed on the silicon wafer.

[0449] (Exposure conditions for post-development defect suppression performance evaluation) The wafer prepared above was subjected to KrF exposure using a KrF excimer laser scanner (ASML, PAS5500 / 850) (NA 0.80). Specifically, for the negative resist, 1 mJ / cm 2 The entire surface was exposed to light without using a mask.

[0450] (Exposure conditions for bridge defect suppression performance evaluation) The resulting wafer was subjected to pattern exposure using a KrF excimer laser scanner (ASML, PAS5500 / 850) (NA 0.80). A binary mask with a line and space pattern with a line size of 175 nm and a space size of 263 nm was used as the reticle. The resulting pattern was adjusted to a line and space pattern with a pitch of 438 nm, a space width of 130 nm, and a line width of 308 nm.

[0451] (Developing conditions) Thereafter, the wafer was baked at 100°C for 60 seconds (Post Exposure Bake; PEB), and then developed by puddling with a developer for 30 seconds. When a rinse treatment was performed, the wafer was puddled with a rinse solution and then rotated at 4000 rpm for 30 seconds to obtain a sample for evaluation. The developer used was FHD-5 manufactured by Fujifilm Electronic Materials Co., Ltd.

[0452] (Evaluation 1: Evaluation of bridge defect suppression performance) The resolution of the exposed LS pattern was observed using a scanning electron microscope (CG4600, manufactured by Hitachi, Ltd.) at a magnification of 200k in n = 300 fields of view, and the number of LS pattern bridges that occurred within each observed field of view was evaluated and recorded as the number of bridge defects in the LS pattern. The smaller this number, the better the chemical's ability to suppress bridge defects. The results were evaluated according to the following criteria and are shown in the table. AA: The number of defects was 10 or less (per field of view). A: The number of defects was more than 10 (pieces / viewpoint) and less than 30 (pieces / viewpoint). B: The number of defects was more than 30 (pieces / viewpoint) and less than 100 (pieces / viewpoint). C: The number of defects was more than 100 (pieces / viewpoint) and less than 300 (pieces / viewpoint). D: The number of defects exceeded 300 (per field of view).

[0453] (Evaluation 2: Evaluation of post-development defect suppression performance) The total number of defects of 19 nm or larger on the entire surface of the wafer was counted using the KLA-Tencor wafer inspection system "SP-5." The results were evaluated according to the following criteria and are shown in the table.

[0454] A: The number of defects was less than 200 per wafer. B: The number of defects was more than 200 / wafer and less than 500 / wafer. C: The number of defects was more than 500 / wafer and less than 1000 / wafer. D: The number of defects was more than 1,000 / wafer but less than 1,500 / wafer. E: The number of defects exceeded 1,500 per wafer.

[0455] [Evaluation 3: Filter life evaluation] The liquid to be purified was continuously purified using each filtration device listed in the table. After the liquid to be purified was passed through the filtration device and the condition of the filtration device stabilized, the resulting chemical solution was immediately collected for testing (initial sample). Subsequently, the chemical solution obtained after purification every 10,000 kg of liquid passed was collected for testing (aged sample). The chemical solutions collected for testing were evaluated using the method for evaluating the bridge defect suppression performance of the chemical solution described in "Evaluation 1." The number of defects per unit area was compared with the initial sample, and the amount of liquid passed when the number of defects in the aged sample doubled was defined as the "lifespan" of the filter. The lifespan of the filter when using the filtration device shown in Figure 25 (chemical solution 303) was defined as 1, and the lifespan of the filter for each device was evaluated as a ratio. The results were evaluated according to the following criteria and are shown in the table. The device used to purify chemical solution 303 was marked "reference" in the evaluation results.

[0456] AA lifespan was more than 10 times longer. A The lifespan was more than 5 times but less than 10 times. B. The lifespan was more than 1x but less than 5x. C The lifespan was less than 1x.

[0457] [Table 1-1-1]

[0458] [Table 1-1-2]

[0459] [Table 1-1-3]

[0460] [Table 1-1-4]

[0461] [Table 1-1-5]

[0462] [Table 1-2-1]

[0463] [Table 1-2-2]

[0464] [Table 1-2-3]

[0465] [Table 1-2-4]

[0466] [Table 1-2-5]

[0467] [Table 1-3-1]

[0468] [Table 1-3-2]

[0469] [Table 1-3-3]

[0470] [Table 1-3-4]

[0471] [Table 1-3-5]

[0472] Table 1 is divided into a first group: Table 1(1-1) to Table 1(1-5), a second group: Table 1(2-1) to Table 1(2-5), and a third group: Table 1(3-1) to Table 1(3-5). Table 1 lists the filters, etc. of the filtration device (or purification device) used to purify each chemical solution, and the evaluation results of the resulting chemical solution, across the corresponding rows of the five contingency tables for each group. For example, in the first group, the first line of each of Tables 1(1-1) to 1(1-5) describes the chemical solution 1. This indicates that chemical solution 1 was produced by the purification apparatus shown in FIG. 14, and that the liquid to be purified used in producing chemical solution 1 contained PGMEA, and its SP value was 17.8. In addition, the filter of the purification apparatus used in producing chemical solution 1 was "PGMEA 1-day immersion" "The purification equipment has a double distillation vessel, BU-1 (a 50 nm pore size filter containing UPE placed at the most upstream side of the flow path), BU-2 (a 15 nm pore size IEX filter placed downstream of BU-1), tank TU-1 upstream of filter A (FA), which includes filter X1 with a 10 nm pore size, BD-1 (a 10 nm pore size filter containing nylon) and BD-2 (a 3 nm pore size filter containing UPE) downstream of filter FA, and tank TD-1 downstream of filter FA. The equipment also shows that circulating filtration was "enabled." Furthermore, Chemical Solution 1 was evaluated using the "pre-wet" method, and the results show that its residue defect suppression performance was AA, its stain defect suppression performance was AA, its bridge defect suppression performance was AA, its pattern width uniformity performance was AA, and the filter life of the refining device was AA. Similarly, the results for chemical solutions 2 to 30 are shown in the tables of the first group, the results for chemical solutions 31 to 56 are shown in the tables of the second group, and the results for chemical solutions 57 to 92 are shown in the tables of the third group.

[0473] From the results shown in the table, the chemical solutions produced using a filtration device (purification device) having a predetermined filter A and a filter different from filter A had excellent defect suppression performance. On the other hand, the filtration device having only filter A did not have the effect of the present invention. Furthermore, chemical solution 1, which was refined using a filtration device in which filter A had an imidization rate of 1.0 or more, had better residue defect suppression performance, better bridge defect suppression performance, and better pattern width uniformity performance than chemical solution 92. [Table 2-1-1]

[0474] [Table 2-1-2]

[0475] [Table 2-1-3]

[0476] [Table 2-1-4]

[0477] Table 2 is divided into Table 2(1-1) to Table 2(1-4). In Table 2, the filtration equipment used for purifying each chemical solution and the evaluation results of the obtained chemical solution are listed across the corresponding rows of each divided table. For example, the first row of each contingency table contains information about the drug solution 201. This indicates that the chemical solution 201 was produced using the filtration device shown in FIG. 20, and that the liquid to be purified used in producing the chemical solution 201 was SPM (4:1). It also indicates that the filter of the filtration device used in producing the chemical solution 201 was pre-cleaned under the condition of "PGMEA 1-day immersion." The filtration device also includes BU-1 (a PTFE-containing filter with a pore size of 200 nm) and BU-2 (a PTFE-containing filter with a pore size of 20 nm). Furthermore, the filtration device includes a tank TU-1 upstream of the filter FA, and as FA (filter A), a filter X3 with a pore size of 15 nm. Downstream of the filter X3, BD-1 (a PTFE-containing filter with a pore size of 10 nm) and BD-2 (a PTFE-containing filter with a pore size of 10 nm) are located downstream, as well as a tank TD-1. It also indicates that circulating filtration was "enabled." The evaluation of the chemical solution 201 indicates that the particle defect suppression performance was A, the stain defect suppression performance was A, and the filter life of the filtration device was A. The results for chemical solutions 202 to 204 are similarly shown in the table above.

[0478] From the results shown in the table, the chemical solutions 201 and 202 refined using a filtration device having filter A and filter B different from filter A had the desired effect. On the other hand, the chemical solutions 203 and 204 refined using a filtration device having only filter A did not have the desired effect.

[0479] [Table 3-1-1]

[0480] [Table 3-1-2]

[0481] [Table 3-1-3]

[0482] Table 3 is divided into Table 3(1-1) to Table 3(1-3). In Table 3, the filtration equipment used for purifying each chemical solution and the evaluation results of the obtained chemical solution are listed across the corresponding rows of each divided table. It has been done. For example, the first row of each contingency table contains information about the drug solution 301. This indicates that the chemical solution 301 was produced by the filtration device shown in FIG. 26, and that the liquid to be purified used in producing the chemical solution 301 was resist resin composition 2. It also indicates that the filter of the filtration device used in producing the chemical solution 301 was pre-cleaned under the condition of "PGMEA 1-day immersion." It also indicates that the filtration device has BU-1 (a filter containing nylon with a pore size of 10 nm), and further has tank TU-1 upstream of filter FA, which has filter X3 with a pore size of 15 nm as FA (filter A), and downstream of that has BD-1 (a filter containing UPE with a pore size of 1 nm). It also indicates that circulating filtration was "enabled." The evaluation of the chemical solution 301 indicates that the performance of suppressing bridge defects was A, the performance of suppressing defects after development was A, and the life of the filter of the filtration device was A. The results for chemical solutions 302 to 309 are similarly shown in the table above.

[0483] From the results shown in the table, chemical solutions 301-302, 304-305, and 307-308, which were refined using a filtration device having filter A and filter B different from filter A, had the desired effects. On the other hand, chemical solutions 303, 306, and 309, which were refined using a filtration device having only filter A, did not have the desired effects.

[0484] [Table 4-1-1]

[0485] [Table 4-1-2]

[0486] [Table 4-1-3]

[0487] Table 4 is divided into Table 4(1-1) to Table 4(1-3). In Table 4, the filtration equipment used for purifying each chemical solution and the evaluation results of the obtained chemical solution are listed across the corresponding rows of each divided table. For example, the first row of each contingency table contains information about the drug solution 310. This indicates that the chemical solution 310 was produced by the filtration device shown in FIG. 27, and that the liquid to be purified used in producing the chemical solution 310 was resist resin composition 2. It also indicates that the filter of the filtration device used in producing the chemical solution 310 was pre-cleaned under the condition of "PGMEA 1-day immersion." It also indicates that the filtration device has BU-1 (a filter containing nylon with a pore size of 20 nm), and further has a tank TU-1 upstream of filter FA, which has filter S with a pore size of 7 nm and a B value of 8 nm as FA (filter A), and downstream of that has BD-1 (a filter containing UPE with a pore size of 1 nm). It also indicates that circulating filtration was "enabled." The evaluation of the chemical solution 301 indicates that the bridge defect suppression performance was AA, the post-development defect suppression performance was A, and the filter life of the filtration device was A. The results for the chemical solutions 311 to 313 are similarly shown in the table above. From the results shown in the table, it was found that the chemical solutions 310 to 313 refined using a filtration device having filter A and a filter different from filter A had the effects of the present invention.

[0488] Chemical solutions 1 to 13, 15 to 28, 30 to 33, 35 to 92, 201 to 202, 301 to 302, 304 to 305, 307 to 308, and 310 to 313 were each prepared using the same filtration equipment (purification equipment) as listed in the table. No circulating filtration was performed. The resulting chemical solutions were evaluated for the items listed in each table, and each of the resulting chemical solutions had excellent defect suppression performance. It was also confirmed that the filter lifespan was similarly good. [Explanation of symbols]

[0489] 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 Filtration equipment 101 Inlet 102 Outlet 103, 104, 201, 601, 104-1, 104-2 filters 105, 202, 301, 302, 402, 501, 502, 602, 701, 801, 802, 803, 804, 901, 1001, 1002, 1104, 1105, 1305 Piping 401, 401(a), 401(b) Tanks 1100 Manufacturing plant 1101 Distillation apparatus 1200, 1300 purification equipment 1102, 1203, 1303, 1304 Distillers 1103 Portable tanks 1106 Means of transport 1201, 1301 Second inlet 1202, 1302 Second Outlet

Claims

1. A method for producing a chemical solution, comprising a filtration step of purifying a liquid to be purified using a filtration device to obtain a chemical solution, The filtration device is an inlet portion and an outlet portion; A filtration device comprising: a filter A; at least one filter B different from the filter A; and a flow passage extending from the inlet portion to the outlet portion, in which the filter A and the filter B are arranged in series; The filter A is a porous film containing a polyimide resin, the filter B includes at least one filter BD that is disposed downstream of the filter A on the flow path and has a smaller pore size than the filter A, The filtration device further includes a return flow passage capable of returning the purified liquid from the downstream side of the filter BD to the upstream side of the filter A, the filtering step includes a circulation filtering step in which the purified liquid filtered through the filter A and the filter BD is returned to the upstream side of the filter A using the return flow path and filtered again through the filter A and the filter BD, The method for producing a chemical solution, wherein the liquid to be purified is a resist resin composition containing a resin.

2. A method for producing a chemical solution, comprising a filtration step of purifying a liquid to be purified using a filtration device to obtain a chemical solution, the filtration device comprises an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, a flow path extending from the inlet portion to the outlet portion in which the filter A and the filter B are arranged in series, and a tank arranged in series with the filter A on the flow path; The filter A is a porous film containing a polyimide resin, the filter B includes at least one filter BD that is disposed downstream of the filter A on the flow path and has a smaller pore size than the filter A, The filtration device further includes a return flow passage capable of returning the purified liquid from the downstream side of the filter BD to the upstream side of the filter A, the filtering step includes a circulation filtering step in which the purified liquid filtered through the filter A and the filter BD is returned to the upstream side of the filter A using the return flow path and filtered again through the filter A and the filter BD, The method for producing a chemical solution, wherein the liquid to be purified is a resist resin composition containing a resin.

3. A method for producing a chemical solution as described in claim 1 or 2, wherein the filter B further includes at least one filter BU containing nylon, which is arranged upstream of the filter A on the flow path.

4. The method for producing a chemical solution according to any one of claims 1 to 3, wherein the resin contains a repeating unit having a lactone structure.

5. The method for producing a chemical solution according to any one of claims 1 to 3, wherein the resin contains a repeating unit represented by general formula (I): 【Chemical 1】 In the formula, R ４１ , R ４２ and R ４３ each independently represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. ４ represents a single bond. ４ represents a single bond. ４ represents a benzene ring group, and n represents an integer of 1 to 5.

6. 4. The method for producing a chemical solution according to claim 1, wherein the resin comprises a resin having a group that is decomposed by the action of an acid to generate a polar group, and a hydrophobic resin.

7. The method for producing a chemical solution according to any one of claims 1 to 6, further comprising the step of immersing the filter A and the filter B in a cleaning solution before the filtering step.

8. 8. The method for producing a chemical solution according to claim 7, wherein the cleaning solution contains at least one selected from the group consisting of a hydroxyaliphatic carboxylic acid ester, an aliphatic carboxylic acid ester, a linear or cyclic ketone, an alkylene glycol monoalkyl ether, an alkylene glycol monoalkyl ether acetate, and an aprotic polar solvent.

9. The method for producing a chemical solution according to any one of claims 1 to 8, wherein the polyimide resin has an imidization rate of 1.0 or more.

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