JP6749196B2 - Method for manufacturing chemical purified product for lithography and method for forming resist pattern - Google Patents

Description

The present invention relates to a method for manufacturing a chemical liquid purified product for lithography and a method for forming a resist pattern.

In the lithographic technique, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a development process is performed to form a resist pattern having a predetermined shape on the resist film. A forming process is performed. A resist material in which the exposed portion of the resist film changes to a characteristic that dissolves in a developing solution is called a positive type, and a resist material in which the exposed portion of the resist film changes to a characteristic that does not dissolve in a developing solution is called a negative type.
In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, pattern miniaturization has been rapidly progressing due to advances in lithography technology. As a pattern miniaturization method, generally, the wavelength of an exposure light source is shortened (increased in energy). Specifically, conventionally, ultraviolet rays represented by g-line and i-line have been used, but nowadays, mass production of semiconductor elements using KrF excimer laser and ArF excimer laser is being carried out. In addition, EUV (extreme ultraviolet), EB (electron beam), X-ray, etc., having a shorter wavelength (high energy) than these excimer lasers are also being studied.
The resist material is required to have lithographic properties such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern having a fine dimension.
As a resist material satisfying such requirements, a chemically amplified resist composition conventionally containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component which generates an acid upon exposure. Is used.

As the pattern becomes finer, resist materials are required to improve various lithographic properties and suppress the occurrence of defects (surface defects).
Here, the "defect" is, for example, all defects detected when the resist pattern after development is observed from directly above by a surface defect observing device (trade name "KLA") manufactured by KLA Tencor Co., Ltd. .. This defect is, for example, a defect due to adhesion of foreign matter or precipitates on the resist pattern surface such as scum (resist residue), bubbles, and dust after development, bridge between line patterns, and hole filling of contact hole pattern holes. And other defects related to the pattern shape, pattern unevenness, and the like.

In addition, in resist materials, there is also a problem of foreign matter aging characteristics (one of storage stability), in which fine particles of foreign matter are generated during storage of a resist solution (resist composition in a solution state). Is desired.

Conventionally, in the production of a resist composition, in order to remove foreign matters, purification by passing through a filter is generally performed. However, the method of allowing the resist composition to pass through a conventionally used membrane filter or depth filter has been insufficient to suppress the occurrence of defects in the resist pattern after development.
Both the step of passing a nylon filter and the step of passing a filter made of a polyolefin resin or a fluororesin are provided in order to suppress the occurrence of defects in the resist pattern and to meet the requirement of the resist material over time characteristics of the resist material. A method for producing a resist composition has been proposed (see Patent Document 1).

In addition to the resist composition, various lithography chemicals such as a resin solution containing a resin, a developing solution, a resist solvent and a pre-wet solvent are used for forming the resist pattern. As a method of removing foreign matters (impurities) such as particles mixed in these chemicals, a method using a filter has been conventionally used.
As the pattern becomes finer, the influence of impurities present in these chemicals also appears in the pattern formation.

Patent No. 4637476

With further progress of lithography technology and further miniaturization of resist patterns, when forming resist patterns with a size of tens to hundreds of nanometers, defects such as scum and microbridges after development become significant problems. Therefore, more than ever, there is a need for a technique capable of suppressing the occurrence of defects in the resist pattern after development.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a chemical liquid purified product for lithography in which impurities are further reduced, and a method for forming a resist pattern.

The inventors of the present invention have studied to refine a lithographic chemical solution such as a resist composition by passing it through a filter having a porous structure in which adjacent spherical cells are in communication with each other, whereby a conventionally used membrane filter or depth is used. The present invention has been completed by finding that the generation of particulate foreign matter during storage is remarkably suppressed (the time-dependent characteristic of foreign matter is significantly improved) as compared with the case of purification by passing through a filter.

That is, the method for producing a purified chemical liquid product for lithography according to the first aspect of the present invention has a step of filtering the chemical liquid for lithography with a filter, and the filter has a porous structure in which adjacent spherical cells communicate with each other. It is characterized by having.

The resist pattern forming method according to the second aspect of the present invention comprises a base material component (A) whose solubility in a developing solution is changed by the action of an acid, and an organic solvent component (S), and has an acid generating ability. A step of obtaining a resist composition purified product by filtering the resist composition provided with a filter having a porous structure in which adjacent spherical cells communicate with each other, and using the purified resist composition product, a resist film is formed on a support. The method is characterized by including a step of forming, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

According to the present invention, it is possible to provide a method for producing a chemical liquid purified product for lithography in which impurities are further reduced, and a method for forming a resist pattern.

It is the figure which showed typically one Embodiment of the communicating hole which comprises a porous film. It is a SEM image which observed the surface of the porous membrane which is this embodiment with a scanning electron microscope. 3 is an SEM image of a surface of a polyamide (nylon) porous film observed by a scanning electron microscope. It is a SEM image which observed the surface of a polyethylene porous membrane with a scanning electron microscope.

In the present specification and claims, the term “aliphatic” is defined as a concept relative to aromatic and means a group, compound or the like having no aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups.
The “halogenated alkyl group” is a group in which a part or all of hydrogen atoms of an alkyl group are substituted with a halogen atom, and the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The “fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which some or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms.
The “constituent unit” means a monomer unit (monomer unit) that constitutes a polymer compound (resin, polymer, copolymer).
“Exposure” is a concept that includes all radiation irradiation.

“Styrene” is a concept including styrene and those in which the hydrogen atom at the α-position of styrene is substituted with other substituents such as an alkyl group, a halogenated alkyl group, and a hydroxyalkyl group.
The term "styrene derivative" is intended to include those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group and a halogenated alkyl group, and derivatives thereof. Examples of these derivatives include those in which a substituent is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α-position may be substituted.
The α-position (carbon atom at the α-position) means the carbon atom to which the benzene ring is bonded, unless otherwise specified.

The alkyl group as the α-position substituent is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Further, the halogenated alkyl group as the α-position substituent is specifically a group in which a part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” is substituted with a halogen atom. To be Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as the α-position substituent include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” are substituted with hydroxyl groups. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.

(Manufacturing method of chemical liquid purified product for lithography)
The method for producing a purified chemical liquid product for lithography according to the first aspect of the present invention includes a step of filtering the chemical liquid for lithography with a filter (hereinafter referred to as “filtration step”).
In the filtration step, the chemical liquid for lithography is purified. Thus, impurities such as particles are removed, and a highly purified chemical liquid purified product for lithography is obtained.
According to such a manufacturing method, in particular, since the filter having the porous structure in which the adjacent spherical cells communicate with each other is used, it has been difficult to remove the object to be filtered (chemical solution for lithography) from the related art. Highly polar components and polymers are sufficiently removed, and in particular, highly polar polymers are specifically removed.
In addition, in the filtration step, metal components as impurities are sufficiently removed from the object to be filtered. This metal component may be originally contained in the components that make up the chemical liquid, but may be mixed from the chemical liquid transfer route such as the pipe of the manufacturing apparatus or the joint. In the filtration step, for example, iron, nickel, zinc, chromium, etc., which are easily mixed from a manufacturing apparatus or the like, can be effectively removed.

<Filtration process>
In the filtration step in the present invention, the chemical liquid for lithography is filtered by a filter having a porous structure in which adjacent spherical cells communicate with each other.
Details of the chemical liquid for lithography, which is an object to be filtered, will be described later. In particular, the effect of the present invention is remarkable when the lithographic chemical containing a resin is an object to be filtered.

≪ Filter ≫
The filter used in the filtration step has a porous structure in which adjacent spherical cells communicate with each other.
For example, such a filter may be made of a single porous membrane in which adjacent spherical cells are in communication with each other, or may be a filter in which another filter material is used together with the porous membrane.
Examples of other filter materials include nylon membranes, polytetrafluoroethylene membranes, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA) membranes and membranes modified with these.

In such a filter, the region of the porous membrane before and after the passage of the liquid is preferably sealed so that the supply liquid of the object to be filtered (chemical liquid for lithography) and the filtrate are separated without being mixed. As the sealing method, for example, the porous film is processed by adhesion by light (UV) curing or adhesion by heat (including adhesion by anchor effect (heat welding etc.)) or adhesion using an adhesive agent. Or a method in which the porous membrane and another filter medium are bonded and processed by an assembling method or the like. Examples of such a filter include those in which the above-mentioned porous membrane is provided in an outer container made of a thermoplastic resin (polyethylene, polypropylene, PFA, polyether sulfone (PES), polyimide, polyamideimide, etc.). ..
In such a filter, the form of the porous membrane may be a flat shape or a pipe shape in which opposite sides of the porous membrane are combined. The pipe-shaped porous membrane preferably has a fold-like surface from the viewpoint of increasing the area of contact with the supply liquid.

-About "porous membrane in which adjacent spherical cells communicate with each other" The above-mentioned "porous membrane in which adjacent spherical cells communicate with each other" provided in the filter used in the filtration step is a communication in which adjacent spherical cells communicate with each other. Has holes.
The communicating pores are formed by individual pores (cells) that impart porosity to the porous membrane. Such holes include holes in which almost the entire inner surface of the hole is a curved surface, and holes of other shapes may be included.

In the present invention, a hole in which almost the entire inner surface of the hole is a curved surface is referred to as a "spherical cell" or "substantially spherical hole". In the spherical cell (generally spherical hole), the inner surface of the hole forms a substantially spherical space. The spherical cell is easily formed when the fine particles used in the method for producing a porous polyimide resin film described later are substantially spherical.
The “substantially spherical shape” is a concept including a true sphere, but is not necessarily limited to a true sphere, and is a concept including a substantially spherical shape. “Substantially spherical” means that the sphericity defined by the major axis/minor axis, which is represented by a value obtained by dividing the major axis of the particle by the minor axis, is within 1±0.3. To do. The sphericity of the spherical cell here is preferably within 1±0.1, more preferably within 1±0.05.
In a porous membrane in which adjacent spherical cells communicate with each other, at least some of the communication holes are formed between the adjacent spherical cells.

FIG. 1 schematically shows one embodiment of the communication holes forming the porous membrane.
In the porous membrane of the present embodiment, the spherical cells 1a and the spherical cells 1b each have a substantially curved inner surface to form a substantially spherical space.
The spherical cell 1a and the spherical cell 1b are adjacent to each other, and a communication hole 5 is formed through which an overlapping portion Q of the adjacent spherical cell 1a and the spherical cell 1b penetrates. Then, the object to be filtered flows through the communication hole 5 in the direction from the spherical cell 1a to the spherical cell 1b (arrow direction), for example.

As described above, in a porous membrane having a structure in which adjacent spherical cells communicate with each other, a plurality of pores (spherical cells, communicating pores) are connected to each other to form a flow path for the filtration object as a whole. preferable.
The "flow path" is usually formed by connecting individual "holes" and/or "communication holes" to each other. The individual pores are formed, for example, by removing individual fine particles present in the polyimide-based resin-fine particle composite film in a subsequent step in the method for producing a polyimide-based resin porous film described later. Further, the communication holes, in the method for producing a polyimide-based resin porous film described below, existing in the polyimide-based resin-fine particle composite film, in the portion where the individual fine particles were in contact with each other, the fine particles are removed in a later step. The adjacent holes are formed by the above.

FIG. 2 is an SEM image obtained by observing the surface of the porous film of the present embodiment with a scanning electron microscope (accelerating voltage 5.0 kV, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation).
The porous membrane 10 of the present embodiment has a porous structure in which adjacent spherical cells 1 communicate with each other.
In the porous film 10, the spherical cells 1 and the communication holes in which the adjacent spherical cells 1 communicate with each other are formed, and the degree of porosity is increased. Further, in the porous membrane 10, the spherical cell 1 or the communicating hole opens on the surface of the porous membrane 10, and the communicating hole that opens on one surface communicates the inside of the porous membrane 10 with the other (backside) surface. A channel is formed which opens to the inside to allow the fluid to pass through the inside of the porous membrane 10. Then, according to the porous membrane 10, the foreign matter contained in the filtration target object is removed from the filtration target object before the filtration because the filtration target object flows through the flow path.

Since the porous membrane 10 has a flow path inside which the communication holes formed by the spherical cells 1 having a curved surface on the inside are continuous, the surface area of the inner surface of the spherical cells 1 is large. As a result, the filtration target not only can pass through the inside of the porous membrane 10 but also increases the frequency of contact with the inner surface of the spherical cell 1 when passing through while contacting the curved surface of each spherical cell 1. The foreign matter existing in the object is adsorbed by the inner surface of the spherical cell 1 so that the foreign matter is easily removed from the object to be filtered.

The porous membrane 10 preferably has a structure in which the spherical cells 1 having an average spherical diameter of 50 to 2000 nm communicate with each other. The average spherical diameter of the spherical cell 1 is more preferably 100 to 1000 nm, further preferably 200 to 800 nm.
The average spherical diameter of the spherical cells 1 refers to the average value of the diameters of the communication holes formed by two adjacent spherical cells. The average spherical diameter of the spherical cell 1 is a value obtained by measuring the diameter of the hole based on the bubble point method using a palm porometer (for example, manufactured by Porous Materials). Specifically, it can be determined by the same method as the average pore size in the porous membrane described later.

The flow path inside the "porous membrane in which adjacent spherical cells communicate with each other" has, in addition to the spherical cells, and the communication holes between the spherical cells, a hole having a shape other than this or a communication hole including the same. May have.
Further, the spherical cell may further have a concave portion on its inner surface. In the concave portion, for example, a hole having a smaller diameter than that of the spherical cell may be formed, which opens to the inner surface of the spherical cell.

Examples of the "porous membrane in which adjacent spherical cells communicate with each other" include those containing a resin, and may consist essentially of the resin, preferably 95% by mass or more of the entire porous membrane. , More preferably 98% by mass or more, and further preferably 99% by mass or more is a resin.
The porous film preferably contains a thermosetting resin in terms of foreign matter removability and strength.
Examples of the thermosetting resin here include polyimide, polyamideimide, polybenzoxazole resin, polybenzimidazole resin, aromatic nylon, polyvinylidene fluoride resin, and polyallyl sulfone.
Among these, the porous film preferably contains at least one of polyimide and polyamideimide as a resin, more preferably contains at least a polyimide, and contains only polyimide as a resin, or contains only polyamideimide. It may be one.

As the "porous film in which adjacent spherical cells communicate with each other", it is particularly preferable that 95% by mass or more of the entire porous film is at least one of polyimide and polyamideimide.
In the present specification, the “polyimide resin” means one or both of polyimide and polyamide-imide. The polyimide and the polyamide-imide may each have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and a -NH- bond.
A porous film containing at least one of polyimide and polyamideimide may be referred to as a “polyimide resin porous film”.
Hereinafter, a porous film (polyimide resin porous film) containing a polyimide resin as a resin and in which adjacent spherical cells communicate with each other will be described.

-Polyimide-based resin porous film The polyimide-based resin may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and a -NH- bond.
As the polyimide resin, those having the functional group other than the main chain terminal are preferable. As a preferable thing which has the said functional group other than the main chain terminal, a polyamic acid (polyamic acid) is mentioned, for example.

In the present specification, the “salt-type carboxy group” means a group in which a hydrogen atom in the carboxy group is replaced with a cation component. The “cation component” may be a cation itself which is in a completely ionized state, or a cation constituent which is in an ion-bonded state with —COO ⁻ and is in a state of having virtually no charge. However, it may be a cation constituent having a partial charge in an intermediate state between these two.
When the “cation component” is an M ion component composed of an n-valent metal M, the cation itself is represented as M ^n+, and the cation component is “M _1/n ” in “-COOM _1/n ”. Is an element represented by ".

Examples of the “cation component” include cations obtained by ion dissociation of a compound included in the etching solution described below. Typically, an ionic component or an organic alkali ion component is used. For example, when the alkali metal ion component is a sodium ion component, the cation itself is sodium ion (Na ⁺ ), and the cation constituent element is an element represented by “Na” in “—COONa”. The cation constituent having a partial charge is Na ^δ+ .
The cation component is not particularly limited, and examples thereof include inorganic components; organic components such as NH ₄ ⁺ and N(CH ₃ ) ₄ ⁺ . Examples of the inorganic component include metal elements such as alkali metals such as Li, Na and K; alkaline earth metals such as Mg and Ca. Examples of the organic component include organic alkali ion components. Examples of the organic alkali ion component include NH ₄ ⁺ , for example, a quaternary ammonium cation represented by NR ₄ ⁺ (4 R's each represent an organic group and may be the same or different). The organic group represented by R is preferably an alkyl group, and more preferably an alkyl group having 1 to 6 carbon atoms. Examples of the quaternary ammonium cation include N(CH ₃ ) ₄ ^{+ and the} like.

The state of the cation component in the salt-type carboxy group is not particularly limited, and usually depends on the environment in which the polyimide resin is present, for example, the environment such as an aqueous solution, an organic solvent, or a dry environment. To do. When the cation component is a sodium ion component, for example, in an aqueous solution, it may be dissociated into —COO ⁻ and Na ^+, and when it is in an organic solvent or dried, − It is highly possible that COONa is not dissociated.

The polyimide-based resin may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and a -NH- bond, but when it has at least one of these, it is usually , A carboxy group and/or a salt-type carboxy group, and an -NH- bond. Regarding the carboxy group and/or the salt-type carboxy group, the polyimide-based resin may have only the carboxy group, may have only the salt-type carboxy group, or may have the carboxy group and the salt-type carboxy group. May have both. The ratio of the carboxy group and the salt-type carboxy group that the polyimide resin has, even if the same polyimide resin, for example, may vary depending on the environment in which the polyimide resin exists, and the concentration of the cation component Is also affected.

In the case of polyimide, the total number of moles of the carboxy group and the salt-type carboxy group of the polyimide resin is usually the same as the number of —NH— bonds.
In particular, when a carboxy group and/or a salt-type carboxy group is formed from a part of the imide bond in the polyimide in the method for producing a polyimide porous film described below, a —NH— bond is also formed substantially at the same time. The total number of moles of the carboxy group formed and the salt-type carboxy group is equimolar to the —NH— bond formed.
In the case of the method for producing a polyamide-imide porous film, the total number of moles of the carboxy group and the salt-type carboxy group in the polyamide-imide is not necessarily the same mole as the —NH— bond, and the etching (opening of the imide bond) described below is performed. It depends on conditions such as chemical etching in the process.

The polyimide-based resin preferably has, for example, at least one structural unit selected from the group consisting of structural units represented by the following general formulas (1) to (4).
In the case of a polyimide, those having at least one kind of constitutional unit selected from the group consisting of constitutional units represented by the following general formula (1) and constitutional units represented by the following general formula (2) are preferable.
In the case of polyamide imide, those having at least one kind of constitutional unit selected from the group consisting of constitutional units represented by the following general formula (3) and constitutional units represented by the following general formula (4) are preferable.

In the above formulas (1) to (3), X ^{1 to} X ⁴ may be the same as or different from each other and are a hydrogen atom or a cation component.
R _Ar is an aryl group, and in each of the constitutional units represented by the formula (5) constituting the polyamic acid (polyamic acid) described below or the constitutional units represented by the formula (6) constituting the aromatic polyimide, respectively. Examples thereof include the same as the aryl group represented by R _Ar to which a carbonyl group is bonded.
Y ^{1 to} Y ⁴ are each independently a divalent residue excluding the amino group of the diamine compound, and are a structural unit represented by the formula (5) or a aromatic polyimide that constitutes the polyamic acid described below. The same as the arylene group represented by R′ _Ar in which N is bonded to each of the constituent units represented by the formula (6) is included.

As the polyimide-based resin, a part of the imide bond (-N[-C(=O)] ₂ ) of a general polyimide or polyamide-imide is ring-opened, and in the case of polyimide, the above general formula (1) is used. Alternatively, each of the structural units represented by the general formula (2) and, in the case of polyamide-imide, may have the structural unit represented by the general formula (3).

The polyimide-based resin porous film has a polyimide-based resin having at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and a -NH- bond by opening a part of the imide bond. May be included.

The rate of invariance when a part of the imide bond is opened is determined by the following procedures (1) to (3).
Step (1): Polyimide-based resin porous film that does not undergo an etching (opening of imide bond) step described below (however, when the varnish for producing the porous film contains a polyamic acid, an unbaked composite film is formed). It is assumed that the imidization reaction is substantially completed in the firing step), and the area of the peak representing the imide bond measured by a Fourier transform infrared spectroscopy (FT-IR) apparatus is the same as FT- A value (X01) represented by a value divided by the area of a peak representing benzene measured by an IR device is obtained.
Procedure (2): Etching (opening of imide bond) step described below for a polyimide resin porous film obtained by using the same polymer (varnish) as the porous film for which the value (X01) was obtained. The area of the peak showing the imide bond measured by the Fourier transform infrared spectroscopy (FT-IR) apparatus for the polyimide resin porous film after the measurement of the peak of the peak showing the benzene measured by the FT-IR apparatus. A value (X02) represented by a value divided by the area is obtained.
Procedure (3): The invariance rate is calculated from the following formula.
Invariance rate (%)=(X02)÷(X01)×100

The rate of invariance in the polyimide-based resin porous film is preferably 60% or more, more preferably 70 to 99.5%, and further preferably 80 to 99%.
In the case of a porous film containing polyamideimide, the invariant rate may be 100% because it contains a -NH- bond.

In the case of a polyimide porous film, a value obtained by dividing the area of the peak representing the imide bond measured by the FT-IR device by the area of the peak representing the benzene measured by the FT-IR device is defined as the “imidization rate”. ..
The imidation ratio for the value (X02) obtained in the above procedure (2) is preferably 1.2 or more, more preferably 1.2 to 2, and further preferably 1.3 to 1.6. , Particularly preferably 1.30 to 1.55, and most preferably 1.35 or more and less than 1.5. Further, the imidation ratio for the value (X01) obtained in the above procedure (1) is preferably 1.5 or more.
The higher the imidation ratio, the greater the number of imide bonds, that is, the smaller the number of ring-opened imide bonds.

.. Manufacturing method of polyimide-based resin porous film The polyimide-based resin porous film is a step of forming a carboxy group and/or a salt-type carboxy group from a part of the imide bond in polyimide and/or polyamide-imide (hereinafter referred to as "etching"). Process))).
When a carboxy group and/or a salt-type carboxy group is formed from a part of the imide bond in the etching step, a theoretically equimolar —NH— bond with these groups is also formed substantially simultaneously.

When the resin contained in the polyimide resin porous membrane is substantially made of polyamide-imide, the porous membrane already has a —NH— bond even without performing an etching step, and the foreign matter in the filtration object is Shows a good adsorption force to In such a case, the etching step is not necessarily required because it is not particularly necessary to slow down the flow rate of the object to be filtered, but it is preferable to provide the etching step from the viewpoint of more effectively achieving the object of the present invention.

As a method for producing a polyimide-based resin porous film, an etching step is performed after forming a molding film containing polyimide and/or polyamide-imide as a main component (hereinafter sometimes abbreviated as “polyimide-based resin molding film”). It is preferable to carry out.
The polyimide-based resin molded film, which is the target of the etching process, may be porous or non-porous.
The form of the polyimide-based resin molded film is not particularly limited, but it is preferable that the polyimide-based resin porous film has a thin shape such as a film because the degree of porosity in the obtained polyimide-based resin porous film can be increased. And a thin shape such as a film is more preferable.

As described above, the polyimide-based resin molded film may be non-porous when the etching step is performed, but in that case, it is preferable that the polyimide-based resin molded film be made porous after the etching step.
As a method for making the polyimide resin molded film porous before or after the etching step, a composite film of polyimide and/or polyamideimide and fine particles (hereinafter referred to as “polyimide resin-fine particle composite film”) is used. A method including a step of [removing fine particles] for removing the fine particles to make them porous is preferable.

Examples of the method for producing the polyimide resin porous membrane include the following production method (a) or production method (b).
Manufacturing method (a): a method of performing an etching step on a composite film of polyimide and/or polyamide-imide and fine particles before the [fine particle removal] step Manufacturing method (b): after the [fine particle removal] step Method of performing etching step on polyimide-based resin molded film which has been made porous by step Among these, since the degree of porosity in the obtained polyimide-based resin porous film can be further increased, the latter production method (b) Is preferred.

Hereinafter, an example of a method for producing the polyimide resin porous film will be described.

[Preparation of varnish]
A fine particle dispersion liquid in which fine particles are previously dispersed in an organic solvent, and a polyamic acid or a polyimide or a polyamideimide are mixed at an arbitrary ratio, or by polymerizing tetracarboxylic dianhydride and diamine in the fine particle dispersion liquid. A varnish is prepared by using a polyamic acid or by further imidizing the polyamic acid into a polyimide.
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, it is possible to form a film more uniformly.
The viscosity of the varnish can be measured with an E-type rotational viscometer at a temperature condition of 25°C.

When the above-mentioned varnish is fired (or dried if firing is desired) to form a polyimide resin-fine particle composite film, the ratio of fine particles/polyimide resin is preferably 1 to 4 (mass ratio), and more preferably The resin fine particles are mixed with the polyamic acid or the polyimide or the polyamide-imide so that the mass ratio is 1.1 to 3.5 (mass ratio).
Further, in the case of a polyimide resin-fine particle composite film, the volume ratio of fine particles/polyimide resin is preferably 1.1 to 5, more preferably 1.1 to 4.5, The fine particles are mixed with polyamic acid or polyimide or polyamideimide.
If the mass ratio or the volume ratio is equal to or higher than the preferred lower limit of the range, pores having an appropriate density as a porous membrane can be easily obtained, and if the ratio is equal to or lower than the preferred upper limit of the range, the viscosity of It is possible to stably form a film without causing problems such as increase and cracks in the film.
In addition, in this specification, a volume ratio shows the value in 25 degreeC.

... Fine Particles The fine particle material is not particularly limited as long as it is insoluble in the organic solvent used for the varnish and can be selectively removed after film formation.
Examples of the material for the fine particles include silica (silicon dioxide), titanium oxide, alumina (Al ₂ O ₃ ), and metal oxides such as calcium carbonate as inorganic materials. Examples of the organic material 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. , Organic polymers such as polyester, polyether, and polyethylene.
Among these, silica, such as colloidal silica, is preferable as the inorganic material because minute pores having a curved surface on the inner surface are easily formed in the porous film. As the organic material, acrylic resin such as PMMA is preferable.

The resin fine particles can be selected, for example, from ordinary linear polymers and known depolymerizable polymers without particular limitation according to the purpose. A normal linear polymer is a polymer in which the molecular chain of the polymer is randomly broken during thermal decomposition. A depolymerizable polymer is a polymer that decomposes into a monomer during thermal decomposition. Any polymer can be removed from the polyimide resin film by decomposing into a monomer, a low molecular weight substance, or CO ₂ when heated.

Among depolymerizable polymers, methyl methacrylate or isobutyl methacrylate, which has a low thermal decomposition temperature (polymethylmethacrylate or polyisobutylmethacrylate) alone or a copolymer polymer containing this as a main component, from the viewpoint of handling during pore formation. Is preferred.

The decomposition temperature of the resin fine particles is preferably 200 to 320°C, more preferably 230 to 260°C. When the decomposition temperature is 200° C. or higher, film formation can be performed even when a high boiling point solvent is used for the varnish, and the range of baking conditions for the polyimide resin can be broadened. When the decomposition temperature is 320° C. or lower, only the resin fine particles can be easily removed without thermally damaging the polyimide resin.

It is preferable that the fine particles have a high sphericity because they are likely to have a curved surface on the inner surface of the pores in the formed porous film. The particle diameter (average diameter) of the fine particles used is, for example, preferably 50 to 2000 nm, more preferably 200 to 1000 nm.
When the average diameter of the fine particles is within the above range, when the filtration object is passed through the polyimide resin porous membrane obtained by removing the fine particles, the filtration object is evenly contacted with the inner surface of the pores in the porous membrane. Therefore, the foreign matter contained in the filtration target can be efficiently adsorbed.

The particle size distribution index (d25/d75) of the fine particles is preferably 1 to 6, more preferably 1.6 to 5, and further preferably 2 to 4.
By setting the particle size distribution index to be equal to or more than the preferable lower limit value of the above range, it is possible to efficiently fill the inside of the porous film with the fine particles, so that the flow path is easily formed and the flow velocity is improved. In addition, holes having different sizes are easily formed, different convections are generated, and the foreign matter adsorption rate is further improved.
It should be noted that d25 and d75 are the particle diameter values at which the cumulative frequency of the particle size distribution is 25% and 75%, respectively, and d25 is the larger particle diameter in this specification.

In [Formation of unbaked composite film] described later, when the unbaked composite film is formed into a two-layered structure, fine particles (B1) used for the first varnish and fine particles (B2) used for the second varnish. May be the same as or different from each other. In order to make the pores on the side in contact with the base material more dense, it is preferable that the fine particles (B1) have a particle size distribution index smaller than or the same as that of the fine particles (B2). Alternatively, it is preferable that the fine particles (B1) have a smaller sphericity than the fine particles (B2) or have the same sphericity. Further, it is preferable that the fine particles (B1) have a particle diameter (average diameter) smaller than that of the fine particles (B2). In particular, the fine particles (B1) have a particle diameter of 100 to 1000 nm (more preferably 100 to 600 nm) and a fine particle (B2). Is preferably 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 resin porous film can be increased and the diameter can be made uniform, and the polyimide The strength of the porous film can be increased as compared with the case where only the fine particles (B1) are used in the entire porous resin film.

In the present invention, a dispersant may be further added to the varnish together with the above fine particles for the purpose of uniformly dispersing the fine particles. By further adding the dispersant, the polyamic acid or the polyimide or the polyamide-imide can be more uniformly mixed with the fine particles, and further, the fine particles can be uniformly distributed in the unfired composite film. As a result, a dense opening is provided on the surface of the finally obtained polyimide resin porous film, and the front and back surfaces of the porous film are connected so that the air permeability of the polyimide resin porous film is improved. It is possible to efficiently form the communication hole to be formed.

A known dispersant can be used without particular limitation. Examples of the dispersant include palm fatty acid salt, castor sulfated oil salt, lauryl sulfate salt, polyoxyalkylene allyl phenyl ether sulfate salt, alkylbenzene sulfonic acid, alkylbenzene sulfonate, alkyldiphenyl ether disulfonate, and alkylnaphthalene. Anionic surfactants such as sulfonates, dialkyl sulfosuccinate salts, isopropyl phosphate, polyoxyethylene alkyl ether phosphate salts, polyoxyethylene allylphenyl ether ether phosphate salts; oleylamine acetate, lauryl pyridinium chloride, cetyl pyridinium chloride, lauryl trimethyl Cationic surfactants such as ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, didecyl dimethyl ammonium chloride; coconut alkyl dimethyl amine oxide, fatty acid amide propyl dimethyl amine oxide, alkyl polyaminoethyl glycine hydrochloride, amido betaine type active agent , Amphoteric surfactants such as alanine type surfactants and lauryl imino dipropionic acid; polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene lauryl amine, polyoxyethylene oleyl amine, polyoxyethylene Polystyryl phenyl ether, polyoxyalkylene polystyryl phenyl ether, other polyoxyalkylene primary alkyl ether or polyoxyalkylene secondary alkyl ether nonionic surfactant, polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylenated Castor oil, polyoxyethylenated hydrogenated castor oil, sorbitan lauric acid ester, polyoxyethylene sorbitan lauric acid ester, fatty acid diethanolamide and other polyoxyalkylene nonionic surfactants; octyl stearate, trimethylolpropane tridecanoate, etc. And fatty acid alkyl esters thereof; 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.

.. Polyamic acid The polyamic acid that can be used in the present invention includes those obtained by polymerizing any tetracarboxylic dianhydride and diamine.

····Tetracarboxylic acid dianhydride The tetracarboxylic acid dianhydride can be appropriately selected from tetracarboxylic acid dianhydrides that have been conventionally used as raw materials for synthesizing polyamic acid.
The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride.

Examples of the aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride and bis(2,3-dicarboxyphenyl)methane. Dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic Acid dianhydride, 2,2,6,6-biphenyltetracarboxylic 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 dianhydride, bis(3,3 4-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 4,4-(p -Phenylenedioxy)diphthalic dianhydride, 4,4-(m-phenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8 -Naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylene Tetracarboxylic acid dianhydride, 2,3,6,7-anthracene tetracarboxylic acid dianhydride, 1,2,7,8-phenanthrene tetracarboxylic acid dianhydride, 9,9-bisfluoric anhydride fluorene, 3 , 3′,4,4′-diphenylsulfone tetracarboxylic acid dianhydride and the like.

The aliphatic tetracarboxylic acid dianhydride, for example, ethylene tetracarboxylic acid dianhydride, butane tetracarboxylic acid dianhydride, cyclopentane tetracarboxylic acid dianhydride, cyclohexane tetracarboxylic acid dianhydride, 1, 2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride and the like can be mentioned.

Among the above, aromatic tetracarboxylic dianhydride is preferable from the viewpoint of heat resistance of the obtained polyimide resin. Among them, 3,3′,4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferable from the viewpoints of price and availability.
The tetracarboxylic dianhydrides may be used alone or in combination of two or more.

··· Diamine The diamine can be appropriately selected from the diamines conventionally used as the raw material for synthesizing polyamic acid. The diamine may be an aromatic diamine or an aliphatic diamine, but from the viewpoint of heat resistance of the obtained polyimide resin, the aromatic diamine is preferable. The diamine may be used alone or in combination of two or more.

Examples of aromatic diamines include diamino compounds having one phenyl group or about 2 to 10 phenyl groups bonded. As the aromatic diamine, specifically, phenylenediamine or its derivative, diaminobiphenyl compound or its derivative, diaminodiphenyl compound or its derivative, diaminotriphenyl compound or its derivative, diaminonaphthalene or its derivative, aminophenylaminoindane or its Examples thereof include derivatives, diaminotetraphenyl compounds or their derivatives, diaminohexaphenyl compounds or their derivatives, and cardo type fluorenediamine derivatives.

As the phenylenediamine, m-phenylenediamine and p-phenylenediamine are preferable. Examples of the phenylenediamine derivative include diamines to which an alkyl group such as a methyl group and an ethyl group is bonded, such as 2,4-diaminotoluene and 2,4-triphenylenediamine.

The diaminobiphenyl compound is a compound in which two aminophenyl groups are bound to each other by phenyl groups. Examples of the diaminobiphenyl compound include 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

The diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via other groups. Examples of the other group include an ether bond, a sulfonyl bond, a thioether bond, an alkylene group or a derivative group 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 thereof is one in which one or more hydrogen atoms of the alkylene group are substituted with a halogen atom or the like.

Examples of the diaminodiphenyl compound 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 etc. are mentioned.

The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are bound to each other via other groups. Examples of the other group include those similar to the other groups in the diaminodiphenyl compound.
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.

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

Examples of aminophenylaminoindan include 5 or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindane.

As the diaminotetraphenyl compound, 4,4'-bis(p-aminophenoxy)biphenyl, 2,2'-bis[p-(p'-aminophenoxy)phenyl]propane, 2,2'-bis[p- (P'-aminophenoxy)biphenyl]propane, 2,2'-bis[p-(m-aminophenoxy)phenyl]benzophenone and the like can be mentioned.

Examples of the cardo type fluorenediamine derivative include 9,9-bisanilinefluorene.

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

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

Among the above, phenylenediamine, phenylenediamine derivative, and diaminodiphenyl compound are preferable as the diamine. Among them, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene and 4,4'-diaminodiphenyl ether are particularly preferable from the viewpoints of price, availability and the like.

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

Examples of the organic solvent used for the reaction of tetracarboxylic dianhydride and diamine include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N-containing polar solvents such as N,N-diethylformamide, N-methylcaprolactam, N,N,N′,N′-tetramethylurea; β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valero Lactone-based polar solvents such as lactones, γ-caprolactone, ε-caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cell sorb acetate, ethyl cell Examples include ethers such as sorbacetate; and phenolic solvents such as cresols.

Among these, as the organic solvent, it is preferable to use a nitrogen-containing polar solvent from the viewpoint of the solubility of the polyamic acid formed.
Further, from the viewpoint of film-forming property, it is preferable to use a mixed solvent containing a lactone polar solvent. In this case, the content of the lactone-based polar solvent is preferably 1 to 20% by mass, and more preferably 5 to 15% by mass, based on the entire organic solvent (100% by mass).
As the organic solvent, it is preferable to use at least one selected from the group consisting of a nitrogen-containing polar solvent and a lactone-based polar solvent, and a mixed solvent of a nitrogen-containing polar solvent and a lactone-based polar solvent is used. More preferable.
The amount of the organic solvent used is not particularly limited, but is preferably such that the content of the produced polyamic acid in the reaction liquid after the reaction is 5 to 50% by mass.

The amount of each of the tetracarboxylic dianhydride and the diamine used is not particularly limited, but it is preferable to use 0.50 to 1.50 mol of the diamine with respect to 1 mol of the tetracarboxylic dianhydride, and 0.60 to 0.60. It is more preferable to use 1.30 mol, and it is particularly preferable to use 0.70 to 1.20 mol.

The reaction (polymerization) temperature is generally -10 to 120°C, preferably 5 to 30°C.
The reaction (polymerization) time varies depending on the raw material composition used, but is usually 3 to 24 (hours).
In addition, the intrinsic viscosity of the polyamic acid solution obtained under such conditions is preferably in the range of 1000 to 100000 cP (centipoise) (1 to 100 Pa·s), more preferably 5000 to 70000 cP (5 to 70 Pa·s). is there.
The intrinsic viscosity of the polyamic acid solution can be measured with an E-type rotational viscometer at a temperature condition of 25°C.

... Polyimide The polyimide that can be used in the present invention is not limited to its structure and molecular weight as long as it can be dissolved in the organic solvent used for the varnish, and known ones can be used.
The polyimide may have a condensable functional group such as a carboxy group in a side chain, or a functional group that promotes a crosslinking reaction or the like during firing.

In order to make the polyimide soluble in the organic solvent used for the varnish, it is effective to use a monomer for introducing a flexible bending structure into the main chain.
Examples of this monomer include aliphatic diamines such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, and 4,4′-diaminodicyclohexylmethane; 2-methyl-1,4-phenylene. Aromatic diamines such as diamine, o-tolidine, m-tolidine, 3,3′-dimethoxybenzidine, 4,4′-diaminobenzanilide; polyoxyalkylenes such as polyoxyethylenediamine, polyoxypropylenediamine, polyoxybutylenediamine and the like. Diamine; polysiloxane diamine; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, 2,2-bis(4-hydroxyphenyl)propanedibenzoate -3,3',4,4'-tetracarboxylic dianhydride and the like can be mentioned.

It is also effective to use a monomer having a functional group, which improves the solubility in such an organic solvent. Examples of the monomer having such a functional group include fluorinated diamines such as 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl and 2-trifluoromethyl-1,4-phenylenediamine. Is mentioned.
Furthermore, in addition to the monomer having such a functional group, the monomers exemplified in the above description of the polyamic acid can be used in combination as long as the solubility is not impaired.

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

Examples of the polyimide that can be used in the present invention include aliphatic polyimides (all-aliphatic polyimides) and aromatic polyimides, and among them, aromatic polyimides are preferable.
As the aromatic polyimide, one obtained by subjecting a polyamic acid having a constitutional unit represented by the following general formula (5) to a ring closure reaction thermally or chemically, or a constitution represented by the following general formula (6) It may be obtained by dissolving a polyimide having a unit in a solvent.
In the formula, R _Ar represents an aryl group, and R′ _Ar represents an arylene group.

In the above 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 carbon number of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more 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. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Among them, R _Ar is preferably an aromatic hydrocarbon ring, more preferably benzene or naphthalene, and particularly preferably benzene.
In the above formula, R′ _Ar includes a group obtained by removing two hydrogen atoms from the aromatic ring in R _Ar . Among them, _R'Ar is preferably a group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring, more preferably a group obtained by removing two hydrogen atoms from benzene or naphthalene, and a phenylene obtained by removing two hydrogen atoms from benzene. Groups are particularly preferred.
Aryl group for R _Ar, arylene group for R _'Ar may each have a substituent.

.. Polyamideimide As the polyamideimide usable in the present invention, known ones can be used without being limited to the structure and the molecular weight as long as they can be dissolved in the organic solvent used for the varnish.
Polyamideimide may have a condensable functional group such as a carboxy group in its side chain, or a functional group that promotes a crosslinking reaction or the like during firing.

Such a polyamide-imide is obtained by imidizing a polymer obtained by reacting any trimellitic anhydride and diisocyanate or a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride with a diamine. Any thing can be used without particular limitation.

Examples of the arbitrary reactive derivative of trimellitic anhydride include trimellitic anhydride halides such as trimellitic anhydride chloride and trimellitic anhydride ester.

Examples of the optional diisocyanate include, for example, metaphenylene diisocyanate, p-phenylene diisocyanate, o-tolidine diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4′-oxybis(phenyl isocyanate), 4,4′-diisocyanate. Diphenylmethane, 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.

Examples of the optional diamine include the same diamines as exemplified in the description of the polyamic acid.

... Organic solvent The organic solvent that can be used for preparing the varnish is not particularly limited as long as it can dissolve the polyamic acid and/or the polyimide resin and does not dissolve the fine particles, and tetracarboxylic acid dianhydride. The same as the organic solvent used for the reaction between the substance and the diamine can be mentioned.
The organic solvent may be used alone or in combination of two or more.

The content of the organic solvent in the varnish is preferably 50 to 95% by mass, more preferably 60 to 85% by mass. The solid content concentration in the varnish is preferably 5 to 50% by mass, more preferably 15 to 40% by mass.

Further, in the case of forming a non-baked composite film described below, in the case of forming the non-baked composite film in the form of two layers, the volume of the polyamic acid or the polyimide or the polyamideimide (A1) and the fine particles (B1) in the first varnish The ratio is preferably 19:81 to 45:55. When the volume ratio of the fine particles (B1) is 100 as a whole, the particles are 55 or more to uniformly disperse the particles, and the particles of 81 or less are easy to disperse without agglomeration. Thereby, it becomes possible to uniformly form the holes on the side surface side of the base material of the polyimide resin molded film.
Further, the volume ratio of the polyamic acid or the polyimide or the polyamideimide (A2) to the fine particles (B2) in the second varnish is preferably 20:80 to 50:50. When the volume ratio of the fine particles (B2) is 100 as a whole, when the particle ratio is 50 or more, the particles are easily dispersed uniformly, and when the particle ratio is 80 or less, the particles do not aggregate with each other, and The surface is less likely to crack. This facilitates formation of a polyimide-based resin porous film having good mechanical properties such as stress and elongation at break.

With respect to the above volume ratio, it is preferable that the second varnish has a fine particle content ratio lower than that of the first varnish. By satisfying the above conditions, even if the fine particles are highly filled in polyamic acid or polyimide or polyamide-imide, the strength and flexibility of the unfired composite film, the polyimide resin-fine particle composite film, and the polyimide resin porous film Nature is secured. Further, by providing the layer having a low content ratio of fine particles, the manufacturing cost can be reduced.

When preparing a varnish, in addition to the above-mentioned components, an antistatic agent, a flame retardant, a chemical imidizing agent, a condensing agent for the purpose of antistatic property, flame retardancy imparting, low temperature baking, releasability, coatability, etc. Known components such as a release agent, a surface modifier and the like can be blended as necessary.

[Formation of unbaked composite film]
The unbaked composite film containing polyamic acid or polyimide or polyamideimide and fine particles is formed by, for example, applying the above-mentioned varnish on a base material, and applying 0 to 120° C. (preferably 0 at normal pressure or vacuum). ˜100° C.), more preferably 60 to 95° C. (more preferably 65 to 90° C.) under normal pressure. The coating film thickness is, for example, preferably 1 to 500 μm, more preferably 5 to 50 μm.

A release layer may be provided on the base material if necessary. In the formation of the unbaked composite film, an immersion step in a solvent containing water, a drying step, and a pressing step may be provided as optional steps before the [baking of the unbaked composite film] described below.

The release layer can be prepared by applying a release agent on the substrate and drying or baking. As the release agent used here, a known release agent such as an ammonium alkylphosphate salt-based release agent, a fluorine-based release agent or a silicone-based release agent can be used without particular limitation.
When peeling the dried unsintered composite film from the substrate, a slight amount of the release agent remains on the release surface of the unsintered composite film. Since the remaining release agent may affect the wettability of the surface of the polyimide resin porous film and the mixing of impurities, it is preferable to remove it.
Therefore, it is preferable to wash the unsintered composite film separated from the base material with an organic solvent or the like. Examples of the cleaning method include known methods such as a method of immersing the unbaked composite film in a cleaning solution and then taking it out, and a method of shower cleaning.
In order to dry the unbaked composite film after washing, for example, the unbaked composite film after washing is air-dried at room temperature or heated to an appropriate set temperature in a constant temperature bath. At this time, for example, a method of preventing the deformation can be adopted by fixing the end portion of the unsintered composite film to a mold made of SUS or the like.

On the other hand, in forming the unfired composite film, when the base material is used as it is without providing the release layer, the step of forming the release layer and the step of cleaning the unfired composite film can be omitted.

When the unfired composite film is formed in a two-layered form, first, the first varnish is applied as it is on a base material such as a glass substrate and the temperature is 0 to 120° C. (preferably 0) under normal pressure or vacuum. ˜90° C.), more preferably 10 to 100° C. (more preferably 10 to 90° C.) under normal pressure to form a first unfired composite film having a thickness of 1 to 5 μm.
Subsequently, the second varnish is applied onto the first unsintered composite film, and in the same manner, 0 to 80° C. (preferably 0 to 50° C.), more preferably 10 to 80° C. (more preferably normal pressure). A two-layer unbaked composite film can be formed by drying under conditions of preferably 10 to 30° C. and forming a second unbaked composite film having a film thickness of 5 to 50 μm.

[Firing of unfired composite film]
After the above [deposition of the unbaked composite film], the unbaked composite film is subjected to heat treatment (baking) to obtain a composite film composed of a polyimide resin and fine particles (polyimide resin-fine particle composite film). It is formed.
When the varnish contains a polyamic acid, it is preferable to complete the imidization in this step [baking of the unbaked composite film].

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

The firing does not necessarily have to be clearly separated from the drying in the previous step. For example, when firing at 375° C., a method of raising the temperature from room temperature to 375° C. in 3 hours and then holding at 375° C. for 20 minutes, or raising the temperature from room temperature to 375° C. in steps of 50° C. It is also possible to use a stepwise drying-thermal imidization method in which each step is held for 20 minutes) and finally held at 375° C. for 20 minutes. At that time, a method of preventing deformation by fixing the end portion of the unfired composite film to a mold made of SUS or the like may be adopted.

The thickness of the polyimide resin-fine particle composite film after the heat treatment (baking) is, for example, preferably 1 μm or more, more preferably 5 to 500 μm, and further preferably 8 to 100 μm.
The thickness of the polyimide-based resin-fine particle composite film can be determined by measuring the thicknesses at a plurality of points using a micrometer and averaging these.

This step is an optional step. This step may not be performed particularly when polyimide or polyamide-imide is used for the varnish.

[Particle removal]
After the above [baking of the unbaked composite film], fine particles are removed from the unpolyimide-based resin-fine particle composite film to produce a polyimide-based resin porous film.
For example, when silica is used as the fine particles, the polyimide-based resin-fine particle composite film is brought into contact with low-concentration hydrogen fluoride (HF) water to dissolve and remove the silica, thereby obtaining a porous film. When the fine particles are resin fine particles, the fine resin particles are decomposed and removed by heating at a temperature higher than or equal to the thermal decomposition temperature of the fine resin particles and lower than the thermal decomposition temperature of the polyimide resin, whereby a porous film is obtained.

[Etching (opening of imide bond)]
The etching step can be performed by a chemical etching method, a physical removal method, or a method combining these methods.

-Chemical etching method A conventionally known method can be used for the chemical etching method.
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. Of these, treatment with an inorganic alkaline solution is preferable.
Examples of the inorganic alkaline solution include a hydrazine solution containing hydrazine hydrate and ethylenediamine; a solution of an alkali metal hydroxide such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium silicate, and sodium metasilicate; an ammonia solution; An etching solution containing alkali hydroxide, hydrazine, and 1,3-dimethyl-2-imidazolidinone as main components can be used.
Examples of the organic alkaline solution include primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; dimethylethanolamine. Alcohol amines such as triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and alkaline etching solutions such as cyclic amines such as pyrrole and pyrelidine. The alkali concentration in the etching liquid is, for example, 0.01 to 20% by mass.

Pure water or alcohols can be appropriately selected as a solvent for each of the above-described etching solutions, and a solvent to which an appropriate amount of surfactant has been added can also be used.

-Physical removal method For the physical removal method, for example, a dry etching method using plasma (oxygen, argon, etc.), corona discharge, or the like can be used.

The above-described chemical etching method or physical removal method can be applied before the above [removal of fine particles] or after the above [removal of fine particles].
Above all, it is preferable to apply after the above [removal of fine particles] because the communication holes inside the polyimide resin porous film are more likely to be formed and foreign matter removability is enhanced.

When the chemical etching method is performed in the etching step, a cleaning step for the polyimide resin porous film may be provided after this step in order to remove the excess etching solution.
The washing after the chemical etching may be performed only by washing with water, but it is preferable to combine the washing with acid with the washing with water.

Further, after the etching step, even if the polyimide resin porous film is subjected to heat treatment (rebaking) to improve wettability of the surface of the polyimide resin porous film with an organic solvent and to remove residual organic matters. Good. The heating conditions are the same as the conditions in the above [baking of unbaked composite film].

For example, in the polyimide resin porous membrane manufactured by the above-described manufacturing method, the spherical cells 1 and the communication holes in which the adjacent spherical cells 1 communicate with each other are formed, as in the embodiment shown in FIG. Preferably, a communication hole that opens to one outer surface communicates with the inside of the porous membrane 10 and opens to the other (back side) outer surface so that a flow path through which a fluid can pass through the porous membrane 10 is formed. It has a communication hole that can be secured.

The Gurley air permeability of the "porous membrane in which adjacent spherical cells communicate with each other" in the present invention is, for example, efficiently removing foreign matter while maintaining a high flow rate of the filtration object passing through the porous membrane to some extent. From the viewpoint, 30 seconds or more is preferable. The Gurley air permeability of the porous membrane is more preferably 30 to 1000 seconds, further preferably 30 to 600 seconds, particularly preferably 30 to 500 seconds, and most preferably 30 to 300 seconds. .. When the Gurley air permeability is equal to or lower than the preferable upper limit value of the above range, the degree of porosity (the abundance ratio of communicating holes and the like) is sufficiently high, and thus the effect of removing foreign matter is more easily obtained.
The Gurley air permeability of the porous membrane can be measured according to JIS P 8117.

The "porous membrane in which adjacent spherical cells communicate with each other" in the present invention preferably has communicating pores having a pore diameter of 1 to 200 nm, more preferably 3 to 180 nm, further preferably 5 to 150 nm, and particularly preferably It is 10 to 130 nm.
The diameter of the communication hole means the diameter of the communication hole. It should be noted that one communication hole is usually formed from two adjacent particles by the above-described manufacturing method, and therefore the diameter has, for example, the direction in which the two holes forming the communication hole are adjacent to each other as the longitudinal direction. The case where the diameter is in the direction perpendicular to the longitudinal direction is included.
If the above-mentioned etching (opening of imide bond) step is not provided, the diameter of the communication hole tends to be small.

Further, the average pore diameter of the “porous membrane in which adjacent spherical cells communicate with each other” in the present invention is preferably 100 to 2000 nm, more preferably 200 to 1000 nm, and further preferably 300 to 900 nm.
The average pore size of the porous film is based on the bubble point method using a palm porometer (for example, Porous Materials Co., Ltd.) for the porous film (for example, polyimide porous film) that has been subjected to the above-mentioned chemical etching. It is a value obtained by measuring the diameter of the communication hole. For a porous membrane that does not undergo chemical etching (for example, a polyamide-imide porous membrane), the average particle diameter of the fine particles used to manufacture the porous membrane is the average pore diameter.

The “porous membrane in which adjacent spherical cells communicate with each other” in the present invention is a porous membrane containing pores having an average pore diameter of preferably several hundred nanometer units, as described above. Therefore, for example, even a minute substance in the unit of nanometer can be adsorbed or captured in the pores and/or the communicating pores in the porous membrane.

The pore size of such a communicating hole is a communicating hole formed by adjacent pores when the distribution of the pore size of the individual pores that imparts porosity to the "porous membrane in which adjacent spherical cells communicate with each other" is broad Pore size tends to be smaller.
From the viewpoint of reducing the pore diameter of the communication holes, the porosity of the “porous membrane in which adjacent spherical cells communicate with each other” is, for example, preferably 50% by mass or more, more preferably 60 to 90% by mass, and further preferably 60% by mass. ˜80% by mass, particularly preferably about 70% by mass. When the porosity is equal to or higher than the preferable lower limit value in the above range, the effect of removing foreign matter is more easily obtained. If it is at most the upper limit value of the above range, the strength of the porous film is further enhanced.
The porosity of the porous film can be determined by calculating the ratio of the mass of the fine particles to the total mass of the resin and the fine particles used when manufacturing the porous film.

The "porous film in which adjacent spherical cells communicate with each other" has excellent mechanical properties such as stress and elongation at break.
The stress of the “porous membrane in which adjacent spherical cells communicate with each other” included in the filter used in the filtration step is, for example, preferably 10 MPa or more, more preferably 15 MPa or more, and further preferably 15 to 50 MPa.
The stress of the porous film is a value measured by preparing a sample having a size of 4 mm×30 mm and using a tester under measurement conditions of 5 mm/min.

Further, the breaking elongation of the "porous membrane in which adjacent spherical cells communicate with each other" is, for example, preferably 10% GL or more, and more preferably 15% GL or more. The upper limit of the breaking elongation is, for example, preferably 50% GL or less, more preferably 45% GL or less, and further preferably 40% GL or less. When the porosity of the polyimide resin porous film is lowered, the breaking elongation tends to increase.
The breaking elongation of the porous film is a value measured by making a sample of size 4 mm×30 mm and using a tester under measurement conditions of 5 mm/min.

The thermal decomposition temperature of the "porous membrane in which adjacent spherical cells communicate with each other" is preferably 200°C or higher, more preferably 320°C or higher, even more preferably 350°C or higher.
The thermal decomposition temperature of the porous film can be measured by raising the temperature to 1000° C. at a heating rate of 10° C./min in an air atmosphere.

<<Filtration of chemicals for lithography>>
The filtration step in the present invention includes an operation of passing the chemical liquid for lithography through a filter having a porous structure in which adjacent spherical cells communicate with each other. By such an operation, foreign matter is removed from the chemical liquid for lithography.
Such an operation may be performed without a differential pressure (that is, the lithography chemical may be passed through the filter only by gravity) or may be performed with a differential pressure. Of these, the latter is preferable, and it is preferable to perform an operation of passing the chemical liquid for lithography through the filter by a differential pressure.
Hereinafter, a case where a filter including a polyimide resin porous membrane is used will be described as an example.

The “state in which a differential pressure is provided” means that there is a pressure difference between one side and the other side of the polyimide resin porous membrane included in the filter.
For example, pressurization (positive pressure) that applies pressure to one side of the polyimide resin porous membrane (lithography chemical supply side), and depressurization that makes one side of the polyimide resin porous membrane (filtrate side) a negative pressure. (Negative pressure) and the like. In the filtration step of the present invention, the former pressurization is preferable.

The pressurization is to apply pressure to the liquid supply side of the polyimide resin porous film, in which the chemical liquid for lithography (hereinafter also referred to as “supply liquid”) before passing through the polyimide resin porous film exists. is there.
For example, it is preferable to apply the pressure to the supply liquid side by using the flow liquid pressure generated by the circulation or flow of the supply liquid, or by using the positive pressure of the gas.
The flowing liquid pressure can be generated, for example, by a positive flowing liquid pressure adding method using a pump (a liquid feeding pump, a circulation pump, or the like). Examples of the pump include a rotary pump, a diaphragm pump, a metering pump, a chemical pump, a plunger pump, a bellows pump, a gear pump, a vacuum pump, an air pump and a liquid pump.
When the supply liquid is circulated or sent by a pump, the pump is usually arranged between the supply liquid tank (or the circulation tank) and the polyimide resin porous membrane.

The flowing liquid pressure may be, for example, a pressure applied to the polyimide resin porous film by the supply liquid when passing the supply liquid through the polyimide resin porous film by gravity only, It is preferable that the pressure is applied by a conventional method of adding a fluid pressure.
The gas used for pressurization is preferably a gas which is inert or non-reactive with the supply liquid, and specific examples thereof include nitrogen or a rare gas such as helium or argon.
As a method for applying pressure to the supply liquid side, it is preferable to use positive pressure of gas. At that time, the pressure of the filtrate that has passed through the porous polyimide resin membrane may be atmospheric pressure without decompression.

Further, the pressurization may utilize both the liquid pressure and the positive pressure of the gas. Further, the differential pressure may be a combination of pressurization and depressurization, for example, one that uses both liquid pressure and depressurization, one that uses both positive pressure and depressurization of gas, or liquid flow. It is also possible to use positive pressure and positive pressure and reduced pressure of gas. When the methods of providing a differential pressure are combined, a combination of a flowing liquid pressure and a positive pressure of gas and a combination of a flowing liquid pressure and a reduced pressure are preferable from the viewpoint of simplification of production and the like.
In the present invention, since the polyimide resin porous film is used, even if one method of providing a differential pressure, such as positive pressure by gas, is excellent in foreign matter removal performance.

The depressurization depressurizes the filtrate side that has passed through the polyimide resin porous membrane. For example, depressurization by a pump may be used, but depressurization to vacuum is preferable.

When the operation of passing the liquid chemical for lithography through the filter is performed in a state where a differential pressure is provided, the pressure difference is the film thickness of the polyimide resin porous film used, the porosity or the average pore diameter, or the desired degree of purification, It is appropriately set in consideration of the flow rate, the flow rate, the concentration or viscosity of the supply liquid, and the like. For example, the pressure difference in the case of the so-called cross-flow method (flowing the supply liquid in parallel to the polyimide-based resin porous membrane) is preferably 3 MPa or less, and the so-called dead end method (for the polyimide-based resin porous membrane). The pressure difference in the case of flowing the supply liquid so as to intersect) is preferably 1 MPa or less, for example. The lower limit value of each pressure difference is not particularly limited, and is preferably 10 Pa or more, for example.

In the filtration step of the present invention, the operation of passing the lithographic chemical liquid through the above-described filter including the polyimide resin porous membrane can be performed in a state in which the flow rate of the lithographic chemical liquid (supply liquid) is kept high.
The flow rate in this case is not particularly limited, but for example, the flow rate of pure water when pressurized at 0.08 MPa at room temperature (20° C.) is preferably 1 mL/min or more, more preferably 3 mL/min or more, It is more preferably 5 mL/min or more, particularly preferably 10 mL/min or more. The upper limit of the flow rate is not particularly limited and is, for example, 50 mL/min or less.
In the present invention, since the filter having the above-mentioned polyimide resin porous membrane is used, filtration can be performed while maintaining a high flow rate in this way, and the removal rate of foreign substances contained in the chemical liquid for lithography can be increased. ..

In the filtration step, the operation of passing the chemical liquid for lithography through the filter is preferably carried out by setting the temperature of the chemical liquid for lithography to 0 to 30°C, more preferably 5 to 25°C. ..

In the filtration step, a circulation-type filtration operation in which the chemical liquid for lithography (supply liquid) is constantly circulated and passed through the polyimide resin porous membrane can also be suitably applied.
Further, in the filtration step, the chemical liquid for lithography may be passed through a filter having a polyimide resin porous film multiple times, or at least a filter having a polyimide resin porous film may be passed through a plurality of filters. Good.

In the filtration step, before passing the feed liquid through the polyimide resin porous membrane, washing the polyimide resin porous membrane, improving wettability with respect to the feed fluid, or the surface energy of the polyimide resin porous membrane and the feed fluid. For adjustment, a solution of alcohol such as methanol, ethanol, isopropyl alcohol or the like, acetone, ketone such as methyl ethyl ketone, water, a solvent contained in the supply liquid or a mixture thereof is brought into contact with the polyimide resin porous membrane to pass it through. You may liquid.
In order to bring the solution into contact with the polyimide resin porous film, the solution may be impregnated with the polyimide resin porous film or may be dipped in the solution. By bringing the solution into contact with the polyimide resin porous membrane, for example, the solution can penetrate into the pores inside the polyimide resin porous membrane. The contact between the solution and the polyimide-based resin porous membrane may be carried out in a state where the above-mentioned differential pressure is provided, and particularly under pressure when the solution is also permeated into the pores inside the polyimide-based resin porous membrane. It is preferable to carry out.

<<Chemical liquid for lithography>>
The chemical liquid for lithography that is an object to be filtered is not particularly limited, and various chemical liquids used when manufacturing a semiconductor element or a liquid crystal display element by a technique such as photolithography, DSA lithography, or imprint lithography, or raw materials thereof There are various types of chemical solutions.
Examples of the chemical solution include those containing water; polar solvents such as ketone solvents, ester solvents, alcohol solvents, ether solvents, amide solvents; hydrocarbon solvents and the like. Further, as a chemical liquid for lithography containing a resin, a resin solution in which a resist resin component is dissolved in an organic solvent component, a resist composition, an insulating film composition, an antireflection film composition described below, and a induced self-assembly (Directed Self Assembly). : DSA) block copolymer compositions, resin compositions for imprinting, and the like. In addition, a pre-wet solvent, a resist solvent, a developing solution and the like can be cited as a chemical solution for lithography used in pattern formation and the like.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone and diisobutyl. Examples thereof include ketones, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone and propylene carbonate.
Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl acetate. Ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, etc. Can be mentioned.
Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, Alcohols such as n-octyl alcohol and n-decanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl Examples include glycol ether solvents such as ether, triethylene glycol monoethyl ether, and methoxymethyl butanol.
Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone. Can be mentioned.
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene; and aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane.

As the resin component for resist, the component (A1) described later (a polymer compound having a structural unit (ap) containing a polar group) is preferable.

A resist composition as an object to be filtered has a base material component (A) (hereinafter referred to as “(A) component”) whose solubility in a developing solution is changed by the action of an acid, and an organic solvent component (S) (hereinafter referred to as “S”). (S) component”) and has an acid generating ability.

Examples of such a resist composition include those having an acid generating ability of generating an acid upon exposure, and the component (A) may generate an acid upon exposure, and the addition is made separately from the component (A). The agent component may generate an acid upon exposure.
Such a resist composition, specifically,
(1) It may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “(B) component”),
(2) The component (A) may be a component that generates an acid upon exposure,
(3) The component (A) may be a component which generates an acid upon exposure, and may further contain the component (B).
That is, in the cases of the above (2) and (3), the component (A) becomes “a base material component which generates an acid upon exposure and whose solubility in a developing solution is changed by the action of the acid”. When the component (A) is a base material component that generates an acid upon exposure to light and the solubility of the component in a developing solution changes by the action of the acid, the component (A1) described below generates an acid upon exposure to light, and A polymer compound whose solubility in a developing solution is changed by the action of an acid is preferable. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, a known unit can be used. Among them, the resist composition of the present invention is preferably the case of the above (1).

-Component (A) In the present invention, the "base material component" is an organic compound capable of forming a film, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved and, in addition, a nano-level resist pattern is easily formed.
The organic compound used as the base material component is roughly classified into a non-polymer and a polymer.
As the non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, the term "low molecular weight compound" means a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, one having a molecular weight of 1,000 or more is usually used. Hereinafter, the term "resin" or "polymer compound" refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-equivalent mass average molecular weight by GPC (gel permeation chromatography) is used.

When the resist composition is a "negative resist composition for an alkali developing process" which forms a negative resist pattern in an alkali developing process, or when a "positive resist pattern for a solvent developing process" which forms a positive resist pattern in a solvent developing process. In the case of “type resist composition”, as the component (A), a base component (A-2) soluble in an alkali developing solution (hereinafter referred to as “component (A-2)”) is preferably used, Further, a crosslinking agent component is blended. In such a resist composition, for example, when an acid is generated from the component (B) upon exposure, the acid acts to cause crosslinking between the component (A-2) and the crosslinking agent component, resulting in alkali development. Solubility in liquid decreases (solubility in organic developer increases). Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developing solution (to an organic developing solution). On the other hand, the unexposed area remains soluble in the alkali developing solution (hardly soluble in the organic developing solution) while it does not change. Therefore, the negative resist pattern is formed by developing with the alkali developing solution. It At this time, a positive resist pattern is formed by developing with an organic developer.
As the preferred component (A-2), a resin soluble in an alkali developing solution (hereinafter referred to as "alkali-soluble resin") is used.
As the cross-linking agent component, for example, an amino-based cross-linking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine-based cross-linking agent, or the like is usually used because a good resist pattern with less swelling can be formed, which is preferable. The compounding amount of the crosslinking agent component is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

When the resist composition is a "positive resist composition for an alkali developing process" which forms a positive resist pattern in an alkali developing process, or a "negative for solvent developing process" which forms a negative resist pattern in a solvent developing process. In the case of "type resist composition", as the component (A), a base material component (A-1) whose polarity increases by the action of an acid (hereinafter referred to as "component (A-1)") is preferably used. To be By using the component (A-1), the polarity of the base material component changes before and after the exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When an alkali development process is applied, the component (A-1) is hardly soluble in an alkali developing solution before exposure, and, for example, when an acid is generated from the component (B) due to exposure, the action of the acid causes The polarity is increased and the solubility in an alkaline developer is increased. Therefore, in the formation of a resist pattern, when the resist film obtained by applying the resist composition onto a support is selectively exposed, the exposed portion changes from poorly soluble to soluble in an alkali developing solution. Since the unexposed portion remains sparingly soluble in alkali, it is subjected to alkali development to form a positive resist pattern.
On the other hand, when a solvent development process is applied, the component (A-1) has a high solubility in an organic developing solution before exposure, and when an acid is generated by exposure, it has a high polarity due to the action of the acid. Solubility in organic developer decreases. Therefore, in the formation of a resist pattern, when the resist film obtained by applying the resist composition onto a support is selectively exposed, the exposed portion changes from soluble to slightly soluble in an organic developer. On the other hand, since the unexposed area remains soluble and does not change, it is possible to make a contrast between the exposed area and the unexposed area by developing with an organic developer, and a negative resist pattern is formed.

Examples of the component (A) used in the resist composition of the present invention include a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid, a structural unit (a2) containing a lactone-containing cyclic group, and a polar group. A structural unit (a3) containing a group-containing aliphatic hydrocarbon group, a structural unit (a4) containing an acid non-dissociable cyclic group, a structural unit containing a carbonate-containing cyclic group, or a -SO ₂ -containing cyclic group ( A resin component having a5) or the like is preferable.

..Structural units (a1)
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.
The “acid decomposable group” is an acid decomposable group capable of cleaving at least a part of the bonds in the structure of the acid decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include groups that decompose to form a polar group by the action of an acid.
Examples of the polar group, such as carboxy group, a hydroxyl group, an amino group, such as a sulfo group _(-SO 3 H) and the like. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
Specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
Here, the "acid dissociable group" means
(I) an acid dissociable group capable of cleaving a bond between the acid dissociable group and an atom adjacent to the acid dissociable group by the action of an acid, or
(Ii) A group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after a part of the bond is cleaved by the action of an acid. ,
To both sides.
The acid-dissociable group constituting the acid-decomposable group needs to be a group having a lower polarity than the polar group generated by the dissociation of the acid-dissociable group. When is dissociated, a polar group having a higher polarity than the acid-dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A) increases. Due to the increase in polarity, the solubility in the developing solution relatively changes, the solubility in the developing solution increases in the case of an alkaline developing solution, and the solubility in the developing solution in the case of an organic developing solution increases. Decrease.

The acid dissociable group is not particularly limited, and those proposed so far as the acid dissociable group of the base resin for the chemically amplified resist can be used.

The structural unit (a1) contained in the component (A) may be one type or two or more types.
The proportion of the structural unit (a1) in the component (A) is preferably from 20 to 80 mol%, more preferably from 20 to 75 mol%, and more preferably from 25 to 25, with respect to the total of all structural units constituting the component (A). 70 mol% is more preferable.

..Structural units (a2)
The structural unit (a2) is a structural unit containing a lactone-containing cyclic group (however, excluding those corresponding to the structural unit (a1) described above).
The lactone-containing cyclic group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when the component (A) is used for forming the resist film.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C(═O)— in its ring skeleton. The lactone ring is counted as the first ring, and a lactone ring alone is referred to as a monocyclic group, and a lactone ring having another ring structure is referred to as a polycyclic group regardless of the structure. The lactone-containing cyclic group may be either a monocyclic group or a polycyclic group.

The structural unit (a2) contained in the component (A) may be one type or two or more types.
The proportion of the structural unit (a2) in the component (A) is preferably from 1 to 80 mol%, more preferably from 5 to 70 mol%, based on the total of all structural units constituting the component (A). 65 mol% is more preferable, and 10 to 60 mol% is particularly preferable.

..Structural units (a3)
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (however, the structural units (a1) and (a2) described above are excluded).
When the component (A) has the structural unit (a3), the hydrophilicity of the component (A) is increased, which contributes to improvement in resolution.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and a hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected and used from, for example, many proposals for resins for resist compositions for ArF excimer lasers. The cyclic group is preferably a polycyclic group, and more preferably has 7 to 30 carbon atoms.

The structural unit (a3) contained in the component (A) may be one type or two or more types.
The proportion of the structural unit (a3) in the component (A) is preferably from 5 to 50 mol%, more preferably from 5 to 40 mol%, based on the total of all structural units constituting the component (A), and from 5 to 5. 25 mol% is more preferable.

..Structural units (a4)
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group.
When the component (A) has the structural unit (a4), the dry etching resistance of the resist pattern formed is improved.
The “acid non-dissociable cyclic group” in the structural unit (a4) is a ring which remains in the structural unit as it is without being dissociated even when the acid acts on the acid when the acid is generated from the component (B). It is a formula group.
The proportion of the structural unit (a4) in the component (A) is preferably 1 to 30 mol% and more preferably 10 to 20 mol% based on the total of all structural units constituting the component (A).

..Structural units (a5)
The structural unit (a5) is a structural unit containing a —SO ₂ — containing cyclic group or a carbonate containing cyclic group.

And _- "-SO 2 containing cyclic group", -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO 2 _- sulfur atom (S) is in A cyclic group that forms part of the ring skeleton of the cyclic group. A ring containing —SO ₂ — in its ring skeleton is counted as the first ring, and if it is the only ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C(═O)—O— in its ring skeleton. The carbonate ring is counted as the first ring, and a carbonate ring alone is referred to as a monocyclic group, and a carbonate ring having another ring structure is referred to as a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be either a monocyclic group or a polycyclic group.

The structural unit (a5) contained in the component (A) may be one type or two or more types.
The proportion of the structural unit (a5) in the component (A) is preferably 1 to 80 mol%, more preferably 5 to 70 mol%, and more preferably 10 to 65, with respect to the total of all the structural units constituting the component (A). Mol% is more preferable, and 10-60 mol% is especially preferable.

In the resist composition of the present invention, the component (A) preferably contains a polymer compound (A1) having a structural unit (ap) containing a polar group (hereinafter also referred to as “component (A1)”). In this case, the effect of the present invention is remarkable.
The polar group in the structural unit (ap) includes a hydroxyl group, a cyano group, a carboxy group, a sulfo group, a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, a carbonyl group (-C(=O)). -), carbonyloxy group (-C(=O)-O-), carbonate group (-O-C(=O)-O-), sulfonyl group (-S(=O) _2- ), sulfonyloxy group (-S(=O) _2- O-) and the like.

Examples of the preferred component (A1) include polymer compounds having the structural unit (a1). As the component (A1), specifically, a polymer compound having the structural unit (a1) and the structural unit (a2), a polymer compound having the structural unit (a1) and the structural unit (a3), a structural unit ( a1) and a structural unit (a5), a polymeric compound, a structural unit (a1), a structural unit (a2) and a structural unit (a3), a structural unit (a1) and a structural unit (a3) And a polymer compound having a structural unit (a5).

The mass average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the component (A) is not particularly limited and is preferably 1000 to 50000, more preferably 1500 to 30000, and particularly 2000 to 20000. preferable.

In the resist composition of the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.
The content of the component (A) in the resist composition of the present invention may be adjusted according to the resist film thickness to be formed and the like.

-(S) component The resist composition of the present invention can be prepared by dissolving the resist material in an organic solvent component ((S) component).
As the component (S), any component capable of dissolving each component to be used and forming a uniform solution may be used, and any one of those conventionally known as a solvent for a chemically amplified resist composition may be appropriately used. It can be selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and the like. Polyhydric alcohols; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ethers of the polyhydric alcohols or compounds having an ester bond, monoethyl Derivatives of polyhydric alcohols such as monoalkyl ethers such as ether, monopropyl ether, monobutyl ether or compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl Ether (PGME) is preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethoxy. Esters such as ethyl propionate; Anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Examples thereof include aromatic organic solvents and dimethyl sulfoxide (DMSO).
As the component (S), one type may be used alone, or two or more types may be used as a mixed solvent.
For example, a mixed solvent obtained by mixing PGMEA and a polar solvent is preferable.
The amount of the component (S) used is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the component (S) is used so that the solid content concentration of the resist composition is preferably in the range of 1 to 20% by mass, more preferably 2 to 15% by mass.

-Regarding optional components In addition to the components (A) and (S), the resist composition of the present invention includes an acid generator component (B) (component (B)) that generates an acid upon exposure, an acid diffusion control agent (hereinafter “(D) component”), at least one compound (E) (hereinafter referred to as “(E) component”) selected from the group consisting of organic carboxylic acids, phosphorus oxo acids and derivatives thereof, and fluorine addition. An agent (hereinafter referred to as “component (F)”) and the like may be contained.

Component (B) The component (B) is an acid generator component that generates an acid upon exposure.
The component (B) is not particularly limited, and those which have been proposed as acid generators for chemically amplified resists can be used.
Examples of the component (B) include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes. Examples thereof include acid generators, nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, and disulfone-based acid generators. Above all, it is preferable to use an onium salt-based acid generator.

In the resist composition of the present invention, as the component (B), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass, more preferably 1 to 50 parts by mass, relative to 100 parts by mass of the component (A). , 1 to 40 parts by mass is more preferable. By setting the content of the component (B) within the above range, pattern formation is sufficiently performed. Further, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability becomes better.

-About component (D) Component (D) is an acid diffusion control agent component.
The component (D) acts as a quencher that traps the acid generated by exposure from the component (B) and the like.
The component (D) may be a photodegradable base (D1) (hereinafter referred to as “(D1) component”) that decomposes upon exposure and loses acid diffusion controllability, or a nitrogen-containing organic that does not correspond to the (D1) component. The compound (D2) (hereinafter, referred to as “component (D2)”) may be used.

The content of the component (D1) is preferably 0.5 to 10.0 parts by mass, more preferably 0.5 to 8.0 parts by mass, and still more preferably 1.0 to 8. 0 mass part is more preferable. When it is at least the preferred lower limit of the above range, particularly good lithographic properties or resist pattern shapes are likely to be obtained. When it is at most the upper limit of the above range, the sensitivity can be favorably maintained and the throughput is also excellent.

As the component (D2), an aliphatic amine, particularly a secondary aliphatic amine or a tertiary aliphatic amine is preferable. The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkylamines or alkylalcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms.
The content of the component (D2) is usually 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A). By setting the content within the above range, the resist pattern shape, the stability over time of leaving and the like are improved.

In the resist composition of the present invention, as the component (D), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (D), the content of the component (D) is preferably 0.1 to 15 parts by mass, and 0.3 to 12 parts by mass with respect to 100 parts by mass of the component (A). More preferably, 0.5 to 12 parts by mass is even more preferable. When it is at least the preferred lower limit of the above range, the lithographic properties such as LWR are further improved when the composition is used as a resist composition. Further, a better resist pattern shape can be obtained. When it is at most the upper limit value of the above range, the sensitivity can be favorably maintained and the throughput is also excellent.

Component (E) The component (E) is at least one compound selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives. By containing the component (E), it is possible to prevent the sensitivity from deteriorating, improve the resist pattern shape, and improve the stability over time with leaving.
In the resist composition of the present invention, as the component (E), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (E), the content of the component (E) is usually 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A).

-About (F) component (F) component is a fluorine additive. By containing the component (F), water repellency is imparted to the resist film.
Examples of the component (F) are described in JP2010-002870A, JP2010-032994A, JP2010-277043A, JP2011-13569A, and JP2011-128226A. And the fluorine-containing polymer compound.
In the resist composition of the present invention, as the component (F), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (F), the content of the component (F) is used in the range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

The resist composition further includes a miscible additive, if desired, such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a surfactant, a plasticizer, a stabilizer, a colorant, an antihalation agent. , Dyes, etc. can be appropriately added and contained.

Examples of the insulating film composition that is an object to be filtered include a siloxane polymer, an organic hydridosiloxane polymer, an organic hydridosilsesquioxane polymer, or a copolymer of hydrogensilsesquioxane and an alkoxyhydridosiloxane or a hydroxyhydridosiloxane, And a liquid containing an organic solvent component.
Examples of the insulating film composition include a liquid containing a silsesquioxane resin, an acid generator component that generates an acid upon exposure to light, a cross-linking agent component, and an organic solvent component.

As the antireflection film composition which is an object to be filtered, a composition containing a film constituent material of the antireflection film and an organic solvent component is used. The film constituent material may be an organic material or an inorganic material containing a Si atom, and mainly includes a binder component such as a resin and/or a cross-linking agent, and an absorptive component that absorbs a specific wavelength such as ultraviolet light. Can be mentioned. Each of these components may be used alone as a film constituent material, or two or more types (that is, a resin and a cross-linking agent, a cross-linking agent and a light-absorbing component, a resin and a light-absorbing component, and a resin, a cross-linking agent and a light-absorbing component). ) May be combined to form the film constituent material. In addition, a surfactant, an acid compound, an acid generator, a crosslinking accelerator, a rheology modifier or an adhesion aid may be added to the antireflection film composition, if necessary.
Examples of the antireflective coating composition to be filtered include, for example, a polyfunctional epoxy compound having a plurality of epoxy moieties in a side chain of a core unit and one or more crosslinkable chromophores bonded thereto, and vinyl ether. A liquid containing a crosslinking agent and an organic solvent component can be used.
The “epoxy moiety” refers to at least one of a closed epoxide ring and a ring-opened (reacted) epoxy group such as a reacted or unreacted glycidyl group and a glycidyl ether group.
"Crosslinkable chromophore" refers to a photoattenuating moiety having a crosslinkable group that is free (ie, unreacted) after the chromophore is attached to a polyfunctional epoxy compound.

Examples of the monomer that induces the core unit include tris(2,3-epoxypropyl)isocyanurate, tris(4-hydroxyphenyl)methane triglycidyl ether, trimethylopropane triglycidyl ether, and poly(ethylene glycol)diene. Glycidyl ether, bis[4-(glycidyloxy)phenyl]methane, bisphenol A diglycidyl ether, 1,4-butanediol diglycidyl ether, resorcinol diglycidyl ether, 4-hydroxybenzoic acid diglycidyl ether, glycerol diglycidyl ether, 4,4′-methylenebis(N,N-diglycidylaniline), monoaryldiglycidyl isocyanurate, tetrakis(oxiranylmethyl)benzene-1,2,4,5-tetracarboxylate, bis(2,3-) Those containing polyfunctional glycidyl such as epoxypropyl)terephthalate or tris(oxiranylmethyl)benzene-1,2,4-tricarboxylate; 1,3-bis(2,4-bis(glycidyloxy)phenyl) Adamantane, 1,3-bis(1-adamantyl)-4,6-bis(glycidyloxy)benzene, 1-(2′,4′-bis(glycidyloxy)phenyl)adamantane or 1,3-bis(4′) -Glycidyloxyphenyl) adamantane; poly[(phenylglycidyl ether)-co-formaldehyde], poly[(o-cresylglycidyl ether)-co-formaldehyde], poly(glycidyl methacrylate), poly(bisphenol A-co-epi) Examples include polymers such as chlorohydrin)-glycidyl endcaps, poly(styrene-co-glycidyl methacrylate) or poly(tert-butyl methacrylate-co-glycidyl methacrylate).

Examples of the precursor of the chromophore (compound before binding) include 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 6-hydroxy-2-naphthoic acid, and 3-hydroxy-2-. Naphthoic acid, 1,4-dihydroxy-2-naphthoic acid, 3,5-dihydroxy-2-naphthoic acid, 3,7-dihydroxy-2-naphthoic acid, 1,1′-methylene-bis(2-hydroxy-3) -Naphthoic acid), 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 3,5-dihydroxy Examples include -4-methylbenzoic acid, 3-hydroxy-2-anthracenecarboxylic acid, 1-hydroxy-2-anthracenecarboxylic acid, 3-hydroxy-4-methoxymandelic acid, gallic acid or 4-hydroxybenzoic acid.

The block copolymer composition applied to the DSA technique, which is an object to be filtered, includes, for example, a liquid containing a block copolymer and an organic solvent component.
As the block copolymer, for example, a polymer compound in which the hydrophobic polymer block (b11) and the hydrophilic polymer block (b21) are bonded can be preferably used.
The hydrophobic polymer block (b11) (hereinafter also simply referred to as “block (b11)”) uses a plurality of monomers having relatively different affinities with water, and among the plurality of monomers, an affinity with water. A block composed of a polymer (hydrophobic polymer) obtained by polymerizing a monomer having a relatively low property. The hydrophilic polymer block (b21) (hereinafter also simply referred to as “block (b21)”) is a polymer (hydrophilic polymer) in which one of the plurality of monomers having a relatively high affinity for water is polymerized. ).

The block (b11) and the block (b21) are not particularly limited as long as they are a combination that causes phase separation, but a combination of blocks that are incompatible with each other is preferable.
Further, in the block (b11) and the block (b21), a phase composed of at least one kind of block among a plurality of kinds of blocks constituting the block copolymer can be removed more easily than a phase composed of other kinds of blocks. It is preferably a combination.
The types of blocks constituting the block copolymer may be two types or three or more types.
In addition, in the block copolymer, a partial constituent component (block) other than the block (b11) and the block (b21) may be bonded.

As the block (b11) and the block (b21), for example, a block in which a structural unit derived from styrene or a styrene derivative is repeatedly bonded, or a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. A block in which a structural unit derived from an acrylate ester (a structural unit derived from an (α-substituted) acrylic acid ester) is repeatedly bonded, and a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. A block in which a structural unit derived from acrylic acid (a structural unit derived from (α-substituted)acrylic acid) is repeatedly bonded, a block in which a structural unit derived from siloxane or a derivative thereof is repeatedly bonded, and a block derived from an alkylene oxide Examples thereof include a block in which structural units are repeatedly bonded, a block in which structural units containing a silsesquioxane structure are repeatedly bonded, and the like.

Examples of the styrene derivative include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent such as an alkyl group or a halogenated alkyl group, or derivatives thereof. Examples of these derivatives include those in which a substituent is bonded to the benzene ring of styrene in which the hydrogen atom at the α-position may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group, and the like.
Specific examples of the styrene derivative include α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-t-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene. , 4-methoxystyrene, 4-t-butoxystyrene, 4-hydroxystyrene, 4-nitrostyrene, 3-nitrostyrene, 4-chlorostyrene, 4-fluorostyrene, 4-acetoxyvinylstyrene, 4-vinylbenzyl chloride, etc. Is mentioned.

Examples of the (α-substituted) acrylic acid ester include an acrylic acid ester and an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group, and the like.
Specific examples of the (α-substituted) acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, octyl acrylate, nonyl acrylate, and acrylic. Acrylic esters such as hydroxyethyl acrylate, hydroxypropyl acrylate, benzyl acrylate, anthracene acrylate, glycidyl acrylate, 3,4-epoxycyclohexyl methane acrylate, propyltrimethoxysilane acrylate; methyl methacrylate, ethyl methacrylate , Propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, nonyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, benzyl methacrylate, anthracene methacrylate, glycidyl methacrylate. , Methacrylic acid 3,4-epoxycyclohexylmethane, methacrylic acid esters such as propyltrimethoxysilane methacrylic acid, and the like.

Examples of (α-substituted) acrylic acid include acrylic acid and acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a hydroxyalkyl group, and the like. Specific examples of the (α-substituted) acrylic acid include acrylic acid and methacrylic acid.

Examples of siloxane or its derivative include dimethyl siloxane, diethyl siloxane, diphenyl siloxane, and methyl phenyl siloxane.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, isopropylene oxide, butylene oxide and the like.
As the silsesquioxane structure-containing structural unit, a cage silsesquioxane structure-containing structural unit is preferable. Examples of the monomer that provides the cage-type silsesquioxane structure-containing structural unit include compounds having a cage-type silsesquioxane structure and a polymerizable group.

Examples of such a block copolymer include a polymer in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded and a block in which structural units derived from (α-substituted) acrylic acid ester are repeatedly bonded are bonded. Compound: Polymer compound in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded and a block in which structural units derived from (α-substituted)acrylic acid are repeatedly bonded are bonded; from styrene or a styrene derivative A polymer compound in which a block in which constituent units derived from each other are repeatedly bonded and a block in which constituent units derived from siloxane or a derivative thereof are repeatedly bonded are bonded; a block in which constituent units derived from alkylene oxide are repeatedly bonded , A polymer compound in which a structural unit derived from an (α-substituted) acrylic acid ester is repeatedly bonded; a block in which a structural unit derived from an alkylene oxide is repeatedly bonded; A polymer compound in which a block in which a structural unit that is derived is repeatedly bonded is bonded; a block in which a structural unit that contains a cage silsesquioxane structure is repeatedly bonded, and a structural unit that is derived from an (α-substituted) acrylate ester A polymer compound in which blocks that are repeatedly bonded are combined; a block in which structural units containing a cage silsesquioxane structure are repeatedly bonded, and a block in which structural units derived from (α-substituted)acrylic acid are repeatedly bonded, A polymer compound in which a polymer compound in which a cage-type silsesquioxane structure-containing structural unit is repeatedly bonded and a block in which a structural unit derived from siloxane or a derivative thereof are repeatedly bonded are bonded ..

Specific examples of the block copolymer include polystyrene-polymethylmethacrylate (PS-PMMA) block copolymer, polystyrene-polyethylmethacrylate block copolymer, polystyrene-(poly-t-butylmethacrylate) block copolymer, and polystyrene-polymethacrylic acid block. Copolymers, polystyrene-polymethyl acrylate block copolymers, polystyrene-polyethyl acrylate block copolymers, polystyrene-(poly-t-butyl acrylate) block copolymers, polystyrene-polyacrylic acid block copolymers and the like.

Examples of the organic solvent component used in the insulating film composition, antireflection film composition, and block copolymer composition include the same as the above-mentioned component (S).

Examples of the resin composition for imprints that is an object to be filtered include a liquid containing a cycloolefin-based copolymer, a polymerizable monomer, a photoinitiator, and an organic solvent component.
Examples of the organic solvent component include halogenated hydrocarbons such as methyl chloride, dichloromethane, chloroform, ethyl chloride, dichloroethane, n-propyl chloride, n-butyl chloride and chlorobenzene; benzene, toluene, xylene, ethylbenzene, propylbenzene, butylbenzene. And other alkylbenzenes; ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and other linear aliphatic hydrocarbons; 2-methylpropane, 2-methylbutane, 2,3,3-trimethylpentane , 2,2,5-Trimethylhexane, and other branched-chain aliphatic hydrocarbons; cyclohexane, methylcyclohexane, ethylcyclohexane, decahydroxynaphthalene, and other cyclic aliphatic hydrocarbons; paraffin obtained by hydrorefining petroleum fractions Oil etc. are mentioned.

Examples of the cycloolefin-based copolymer include an amorphous polymer having a structural unit containing a cyclic olefin structure. Specifically, a copolymer having a structural unit containing a cyclic olefin structure and a structural unit containing a non-cyclic olefin structure can be mentioned.
Examples of the structural unit containing a cyclic olefin structure include structural units derived from a diene compound. Examples of the diene compound include 2,5-norbornadiene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, dicyclopentadiene, 5-isopropylidene-2-norbornene and triene. Cyclopentadiene, 1,4,5,8-dimethano-1,4,4a,5,8,8a-hexahydronaphthalene, cyclopentadiene, 1,4-cyclohexadiene, 1,3-cyclohexadiene, 1,5- Cyclodiene such as cyclooctadiene, 1-vinylcyclohexene, 2-vinylcyclohexene, 3-vinylcyclohexene; 4,5,7,8-tetrahydroindene, 4-methyltetrahydroindene, 6-methyltetrahydroindene or 6-ethyltetrahydro Examples thereof include alkyltetrahydroindene such as indene.
As the structural unit containing an acyclic olefin structure, an acyclic monoolefin, for example, a structural unit derived from an α-olefin (preferably ethylene or propylene) having 2 to 20 carbon atoms; acyclic diene (1, 5-hexadiene, 1,4-hexadiene, 1,3-hexadiene, 1,9-decadiene, butadiene, isoprene, etc.) and the like.

As the polymerizable monomer, a monofunctional monomer or a polyfunctional monomer can be used, and examples thereof include a monofunctional monomer, a bifunctional monomer, a trifunctional monomer, a tetrafunctional monomer and a pentafunctional monomer. Functional monomers are preferred. The bifunctional monomer is preferably a bifunctional monomer having an aliphatic cyclic group, and examples thereof include cyclohexanedimethanol diacrylate, cyclohexanedimethanol dimethacrylate, and tricyclodecanedimethanol diacrylate.

The photoinitiator may be any compound that initiates or accelerates the polymerization of the cycloolefin-based copolymer upon irradiation with light, and examples thereof include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1. -One, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one , 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, iodonium, (4-methylphenyl)[4-(2-methylpropyl)phenyl]-hexa Fluorophosphate, a mixture of 2-[2-oxo-2-phenylacetoxyethoxy]ethyl ester and 2-(2-hydroxyethoxy)ethyl ester, phenylglycosylate, benzophenone and the like can be mentioned.

The method for producing a purified chemical liquid product for lithography according to this embodiment is useful for a chemical liquid containing a resin. Among these chemicals containing a resin, the chemicals for photolithography, the chemicals for DSA lithography, and the chemicals for imprint lithography are more useful for resist compositions, block copolymer compositions applied to DSA technology, and imprints. It is particularly useful for resin compositions for use.

The method for producing a purified chemical liquid product for lithography according to this embodiment is particularly useful for a chemical liquid containing the component (A1) among resist compositions.

Further, the method for producing a purified chemical liquid product for lithography according to the present aspect is selected from the group consisting of a pre-wet solvent, a resist solvent, and a developer among various chemical liquids used in the production of semiconductor elements and liquid crystal display elements. It is also useful for drug solutions.

Furthermore, in the method for producing a purified chemical liquid product for lithography of the present embodiment, when a filter including a polyimide resin porous membrane is used as a filter, acid resistance is enhanced, and therefore an object to be filtered showing acidity (chemical liquid for lithography) Is especially useful for.

According to the method for producing a purified chemical liquid product for lithography described above, in the filtration step, the object to be filtered (chemical liquid for lithography) is filtered by a filter having a porous structure in which adjacent spherical cells communicate with each other. It As a result, foreign substances such as organic substances and metallic impurities are removed from the object to be filtered more than ever. In particular, since the shape of the filter is a porous structure in which adjacent spherical cells communicate with each other, high polar components and polymers, which were difficult to remove by the conventional method, are sufficiently removed from the object to be filtered. The polar polymer is specifically removed. In addition, in the filtration step, metal components as impurities are sufficiently removed from the object to be filtered. As described above, according to such a manufacturing method, various foreign substances can be efficiently removed, and a highly purified chemical liquid purified product for lithography can be obtained.

The filtration filter according to the present embodiment is not limited to the one including the porous membrane having the communication hole 5 formed by communicating the adjacent spherical cells 1a and 1b as shown in FIG. In addition to the communication holes 5 communicating with each other, a cell having another form or a porous membrane having communication holes may be provided.
Examples of cells having other forms (hereinafter referred to as “other cells”) include cells having different shapes or pore diameters, such as elliptical cells, polyhedral cells, and spherical cells having different pore diameters. Examples of the above-mentioned "communications holes of other forms" include, for example, communication holes in which spherical cells communicate with other cells.
The shape or pore diameter of other cells may be appropriately determined according to the type of impurities to be removed. The communication hole in which the spherical cell communicates with another cell can be formed by selecting the material of the above-mentioned fine particles or controlling the shape of the fine particles.
According to the filtration filter provided with the porous membrane in which the cells or the communication holes of other forms are formed in addition to the communication holes in which the adjacent spherical cells are communicated with each other, various foreign matters can be more efficiently removed from the object to be filtered. Can be removed.

Further, a filter having a porous structure in which adjacent spherical cells are communicated with each other used in a filtration step is a particulate line which has been installed so far in a supply line of various chemicals in a semiconductor manufacturing process or a POU (point of use). It can be used in place of or in combination with a filter cartridge for removing impurities. Therefore, various foreign matters can be efficiently removed from the object to be filtered by the same apparatus and operation as the conventional one, and a highly purified chemical liquid purified product for lithography can be manufactured.

(Liquid chemical purified product)
The chemical liquid purified product for lithography manufactured by the method for manufacturing a chemical liquid purified product for lithography according to the first aspect described above is filtered through a filter having a porous structure in which adjacent spherical cells communicate with each other. As a result, foreign substances such as organic substances and metal impurities are removed.
The chemical liquid purified product for lithography is a chemical liquid having very few fine particles of, for example, 30 nm or more because it is filtered by a filter having a porous structure in which adjacent spherical cells communicate with each other.

In addition, the defect count measured for the filtrate (purified product of the chemical liquid for lithography) stored at 40° C. for 1 day after filtering the chemical liquid for lithography with a filter having a porous structure in which adjacent spherical cells communicate with each other is , Becomes smaller.
The smaller the value of this defect count, the more the generation of foreign matter is suppressed, that is, the amount of foreign matter is small and it is a high-purity chemical liquid for lithography.

For example, a resist composition produced by using a resin solution refined product in which a resist resin component is dissolved in an organic solvent component as a lithography chemical liquid refined product has a small value of the defect count, and in a resist pattern after development. It is preferable because the generation of defects is further suppressed.
The resist composition containing the resin solution purified product can be manufactured by a manufacturing method including the following steps (i) to (iii) as an example.
Step (i): A step of obtaining a resin solution purified product by filtering a resin solution in which a resist resin component is dissolved in an organic solvent component with a filter having a porous structure in which adjacent spherical cells communicate with each other. : A crude resist composition is prepared by mixing the resin solution purified product and other optional components (the above-mentioned component (B), component (D), component (E), component (F) or component (S)). Step of obtaining Step (iii): Step of filtering the crude resist composition with a filter having a porous structure in which adjacent spherical cells communicate with each other, or a conventional filter

Further, according to the method for producing a chemical liquid purified product for lithography of the first aspect described above, it is possible to produce a resist composition purified product capable of further suppressing the occurrence of defects in the resist pattern after development.
In the manufacturing method according to the present invention, in the filtration step, the resist composition that is an object to be filtered has a porous structure in which adjacent spherical cells communicate with each other and is filtered by a filter having a large surface area. As a result, foreign substances such as organic substances and metallic impurities are removed from the resist composition that is the object of filtration more than ever. In particular, since the morphology of the filter is a porous structure in which adjacent spherical cells are communicated with each other, a high polar component and a polymer, which have been difficult to remove by the conventional resist composition, are sufficient. In particular, highly polar polymers are specifically removed. Therefore, the occurrence of defects in the resist pattern after development is further suppressed.

Further, in the filtration step of the present invention, the metal component as an impurity is sufficiently removed from the object to be filtered. Various base material components and organic solvents that are added to the resist composition contain a trace amount of metal components such as metal ion impurities. The metal component may be originally contained in the blended component, but may be mixed from a chemical liquid transfer route such as a pipe of a manufacturing apparatus or a joint. In the filtering step, for example, iron, nickel, zinc, chromium, etc., which are easily mixed in the step of manufacturing the resist composition, can be effectively removed.
The purified resist composition product after the filtration step is filtered by a filter having a porous structure in which adjacent spherical cells communicate with each other. For example, the metal component concentration is preferably 500 ppt (trillion fraction). Less, more preferably less than 100 ppt, particularly preferably less than 10 ppt.

(Method of forming resist pattern)
The method of forming a resist pattern according to the second aspect of the present invention comprises a base material component (A) whose solubility in a developing solution is changed by the action of an acid and an organic solvent component (S), and has an acid generating ability. A step of obtaining a resist composition purified product by filtering the resist composition provided with a filter having a porous structure in which adjacent spherical cells communicate with each other, and using the purified resist composition product, a resist film is formed on a support. The method includes a step of forming, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

The resist pattern forming method of this embodiment can be performed, for example, as follows.
First, the resist composition purified product is applied on a support by a spinner or the like, and baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature condition of 80 to 150° C. for 40 to 120 seconds, preferably This is applied for 60 to 90 seconds to form a resist film.
The resist composition purified product can be obtained by using the resist composition as the lithography chemical liquid in the method for producing a lithography chemical liquid purified product according to the first aspect.
Next, the resist film is exposed or masked through a mask (mask pattern) on which a predetermined pattern is formed, using an exposure device such as an ArF exposure device, an electron beam drawing device, and an EUV exposure device. After performing selective exposure such as drawing by direct irradiation of an electron beam without intervention, baking (post-exposure bake (PEB)) treatment is performed, for example, at a temperature condition of 80 to 150° C. for 40 to 120 seconds, preferably 60 to Apply for 90 seconds.
Next, the resist film is developed. The development treatment is performed using an alkali developing solution in the case of an alkali developing process, and using a developing solution containing an organic solvent (organic developing solution) in the case of a solvent developing process.
After the development processing, rinsing processing is preferably performed. The rinse treatment is preferably a water rinse using pure water in the case of an alkali developing process, and preferably a rinse liquid containing an organic solvent in the case of a solvent developing process.
In the case of the solvent developing process, after the developing process or the rinsing process, a process of removing the developing solution or the rinsing solution adhering on the pattern with a supercritical fluid may be performed.
After the development treatment or the rinse treatment, drying is performed. Further, depending on the case, a bake treatment (post bake) may be performed after the above development treatment.
In this way, the resist pattern can be formed.

The support is not particularly limited, and a conventionally known support can be used, and examples thereof include a substrate for electronic parts and a substrate having a predetermined wiring pattern formed thereon. More specifically, a silicon wafer, a substrate made of metal such as copper, chromium, iron, and aluminum, a glass substrate, or the like can be given. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be the above-mentioned substrate provided with an inorganic and/or organic film. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and an organic film such as a lower organic film in a multilayer resist method.

The wavelength used for exposure is not particularly limited, and includes ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. It can be done using radiation. The purified resist composition product is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV, and is particularly useful for ArF excimer laser, EB or EUV.

The exposure method of the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or a liquid immersion exposure (Liquid Immersion Lithography).
In the immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index higher than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
As the immersion medium, a solvent having a refractive index higher than that of air and lower than that of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it falls within the above range.
Examples of the solvent having a refractive index higher than that of air and lower than that of the resist film include water, fluorine-based inert liquid, silicon-based solvent, hydrocarbon-based solvent and the like.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples of the liquid include those having a boiling point of 70 to 180°C, and more preferably 80 to 160°C. It is preferable that the fluorine-based inert liquid has a boiling point within the above range, because the medium used for the liquid immersion can be removed after the exposure by a simple method.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.), and examples of the perfluoroalkylamine compound include perfluorotributylamine( The boiling point is 174° C.).
As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility and the like.

Examples of the alkaline developing solution used for the developing treatment in the alkaline developing process include a 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the developing treatment in the solvent developing process may be any one capable of dissolving the component (A) (component (A) before exposure), and among known organic solvents It can be selected appropriately. Specific examples thereof include polar solvents such as a ketone solvent, an ester solvent, an alcohol solvent, a nitrile solvent, an amide solvent, an ether solvent, and a hydrocarbon solvent.
The ketone solvent is an organic solvent containing C—C(═O)—C in the structure. The ester solvent is an organic solvent containing C—C(═O)—O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. The amide-based solvent is an organic solvent containing an amide group in its structure. The ether solvent is an organic solvent containing C—O—C in the structure.
Among the organic solvents, there are also organic solvents containing a plurality of functional groups that characterize the above-mentioned respective solvents in the structure, but in that case, the organic solvent corresponds to any solvent species containing a functional group. I shall. For example, diethylene glycol monomethyl ether corresponds to both the alcohol solvent and the ether solvent in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent that may be halogenated and does not have a substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, and is preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

Known additives can be added to the organic developer as needed. Examples of the additive include a surfactant. Although the surfactant is not particularly limited, for example, an ionic or nonionic fluorine-based and/or silicon-based surfactant or the like can be used. The surfactant is preferably a nonionic surfactant, more preferably a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant.
When the surfactant is blended, the blending amount thereof is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 5 mass% is more preferable.

The development treatment can be carried out by a known development method, for example, a method of dipping the support in a developing solution for a certain period of time (dip method), or raising the developing solution to the surface of the support by surface tension and leaving it stationary for a certain period of time. Method (paddle method), spraying the developer on the surface of the support (spray method), and applying the developer while scanning the developer application nozzle at a constant speed on the support rotating at a constant speed. A method of continuing (dynamic dispensing method) and the like can be mentioned.

As the organic solvent contained in the rinse liquid used in the rinse treatment after the development treatment in the solvent development process, for example, among the organic solvents used as the organic solvent used in the organic developer, those which hardly dissolve the resist pattern are appropriately selected. Can be used. Usually, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent and an ether solvent is used. Among these, at least one selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent and an amide solvent is preferable, and at least one selected from an alcohol solvent and an ester solvent is preferably selected. More preferably, an alcohol solvent is particularly preferable.
These organic solvents may be used alone or in combination of two or more. Further, it may be used by mixing with an organic solvent or water other than the above. However, considering development characteristics, the content of water in the rinse liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and more preferably 3% by mass with respect to the total amount of the rinse liquid. The following are particularly preferred.
Known additives can be added to the rinse liquid as needed. Examples of the additive include a surfactant. As the surfactant, the same ones as described above can be mentioned, and a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferable.
When compounding a surfactant, the compounding quantity is 0.001-5 mass% normally with respect to the total amount of the rinse liquid, 0.005-2 mass% is preferable, and 0.01-0.5 mass%. % Is more preferable.

The rinse treatment (washing treatment) using the rinse liquid can be carried out by a known rinse method. Examples of the rinsing method include a method of continuously applying a rinsing liquid onto a support that is rotating at a constant speed (rotational coating method), a method of immersing the support in the rinsing liquid for a certain period of time (dip method), Examples include a method of spraying a rinsing liquid on the surface of the support (spray method).

According to the resist pattern forming method of the present embodiment described above, since the resist composition purified product that has passed through the filter having a porous structure in which adjacent spherical cells communicate with each other is used, the occurrence of defects is further suppressed, It is possible to form a resist pattern having a good shape in which defects such as scum and microbridge are reduced.

In the resist pattern forming method of the present embodiment, the resist pattern is formed by using a filtrate (refined resist composition product) which is stored at 40° C. for 1 day after being filtered by a filter having a porous structure in which adjacent spherical cells communicate with each other. The defect count for the resist pattern is smaller.
The smaller the value of the defect count, the more the occurrence of defects is suppressed, and the formed resist pattern has less defects such as scum and microbridges and has a good shape.
The defect count of the resist pattern can be obtained by measuring the total number of defects in the support (total number of defects, unit: number) using a surface defect observation device (for example, manufactured by KLA Tencor Co., Ltd.).

As described above, according to the resist composition purified product produced by the method for producing a chemical liquid purified product for lithography of the first aspect, the defect in the resist pattern after development is maintained even after being stored at 40° C. for 1 day. Occurrence is suppressed.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Manufacture of filters>
The following raw materials were used to produce a filter having a polyimide porous membrane and a filter having a polyamideimide porous membrane, respectively.

-Tetracarboxylic acid dianhydride: pyromellitic dianhydride.
-Diamine: 4,4'-diaminodiphenyl ether.
Polyamic acid solution: reaction product of pyromellitic dianhydride and 4,4′-diaminodiphenyl ether (solid content 21.9% by mass), solvent is N,N-dimethylacetamide.
Polyamideimide solution: Polyamideimide containing trimellitic anhydride and o-tolidine diisocyanate as polymerization components (mass average molecular weight Mw: about 30,000; solid content 14.0% by mass), solvent: N-methyl-2-pyrrolidone.
-Organic solvent (1): N,N-dimethylacetamide (DMAc).
-Organic solvent (2): γ-butyrolactone.
-Organic solvent (3): N-methyl-2-pyrrolidone (NMP).
-Dispersant: Polyoxyethylene secondary alkyl ether-based dispersant.
Fine particles: silica (1) (silica having a volume average particle diameter of 300 nm, particle diameter distribution index is about 1.5).

As the etching liquid, the following etching liquid (1) was used.
・Etching liquid (1)
A TMAH solution having a concentration of 1.0% by mass, and a solvent is a mixed solvent of methanol:water=4:6 (mass ratio).

<<Production of Polyimide Porous Membrane>>
[Preparation of silica dispersion (a)]
23.1 parts by mass of silica (1) was added to a mixture of 23.1 parts by mass of organic solvent (1) and 0.1 part by mass of a dispersant, and the mixture was stirred to prepare a silica dispersion liquid (a).

[Preparation of varnish]
42.0 parts by mass of the silica dispersion liquid (a) was added to 41.1 parts by mass of the polyamic acid solution.
Next, the total of the organic solvent (1) and the organic solvent (2) was 66.9 parts by mass, and the solvent composition in the entire varnish was as follows: organic solvent (1):organic solvent (2)=90:10 (mass ratio). The varnish was prepared by adding the above ingredients and stirring.
The volume ratio of polyamic acid to silica in the obtained varnish was 40:60 (mass ratio 30:70).

[Formation of unbaked composite film]
The varnish obtained in the above [Preparation of varnish] was applied onto a PET film as a substrate using an applicator. Then, prebaking was performed at 90° C. for 5 minutes to form a coating film having a film thickness of 40 μm. Then, the formed coating film was immersed in water for 3 minutes. Then, the coating film was pressed between two rolls. At that time, the roll pressing pressure was 3.0 kg/cm ² , the roll temperature was 80° C., and the moving speed of the unsintered composite film was 0.5 m/min. After the pressing, the coating film was peeled off from the base material to obtain an unfired composite film.

[Firing of unfired composite film]
The unsintered composite film obtained in [Formation of unsintered composite film] is imidized by performing heat treatment (sintering) at a sintering temperature of 400° C. for 15 minutes to obtain a polyimide-fine particle composite film. It was

[Particle removal]
Fine particles contained in the composite film were removed by immersing the polyimide-fine particle composite film obtained in the above [baking of unfired composite film] in a 10% HF solution for 10 minutes.
Then, it was washed with water and dried to obtain a polyimide porous film (PIm(1)).

The obtained polyimide porous film (PIm(1)) was observed with a scanning electron microscope (accelerating voltage 5.0 kV; trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). PIm(1) had a porous structure in which communication holes were formed in which adjacent spherical cells were communicated with each other, as shown in FIG.

[Chemical etching]
By immersing the polyimide-fine particle composite film obtained in the above [calcination of unfired composite film] in a 10% HF solution for 10 minutes, fine particles contained in the composite film are removed to obtain a porous body. It was Then, it was washed with water and dried.
Then, according to the chemical etching conditions shown in the "CE" column of Table 1, the above-mentioned porous body after being washed with water and dried was immersed in a predetermined etching solution for a predetermined time. The chemical etching conditions shown in Table 1 are as follows.
Condition 1: Immerse in etching solution (1) for 2 minutes.
Then, a polyimide porous film (PIm(2)) was obtained by performing a heat treatment (rebaking) at a rebaking temperature of 380° C. for 15 minutes.

The obtained polyimide porous film (PIm(2)) was observed with a scanning electron microscope (accelerating voltage 5.0 kV; trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). PIm(2) had a porous structure in which communication holes were formed in which adjacent spherical cells were communicated with each other, as shown in FIG.

<<Manufacture of Polyamideimide Porous Membrane>>
[Preparation of silica dispersion (b)]
19.3 parts by mass of silica (1), 19.3 parts by mass of organic solvent (3) and 0.1 part by mass of a dispersant were mixed and stirred to prepare a silica dispersion (b).

[Preparation of varnish]
35.0 parts by mass of the silica dispersion (b) was added to 53.6 parts by mass of the polyamide-imide solution.
Then, 33.7 parts by mass in total of the organic solvent (1) and the organic solvent (3) was used, and the solvent composition in the entire varnish was as follows: organic solvent (1):organic solvent (3)=5:95 (mass ratio). The varnish was prepared by adding the above ingredients and stirring.
The volume ratio of polyamideimide to silica (1) in the obtained varnish was 40:60 (mass ratio 30:70).

[Formation of unbaked composite film]
The varnish obtained in the above [Preparation of varnish] was applied onto a PET film as a substrate using an applicator. Then, prebaking was performed at 90° C. for 5 minutes to form a coating film having a film thickness of 40 μm. Then, the formed coating film was immersed in water for 3 minutes. Then, the coating film was pressed between two rolls. At that time, the roll pressing pressure was 3.0 kg/cm ² , the roll temperature was 80° C., and the moving speed of the unsintered composite film was 0.5 m/min. After the pressing, the coating film was peeled off from the base material to obtain an unfired composite film.

[Firing of unfired composite film]
By subjecting the unsintered composite film obtained in [Formation of unsintered composite film] to heat treatment (sintering) at 280° C. for 15 minutes, a polyamideimide-fine particle composite film was obtained.

[Particle removal]
The fine particles contained in the composite film were removed by immersing the polyamideimide-fine particle composite film obtained in the above [baking of unfired composite film] in a 10% HF solution for 10 minutes.
Then, washing with water and drying were performed to obtain a polyamide-imide porous membrane (PAIm).

The obtained polyimide porous film (PAIm) was observed with a scanning electron microscope (accelerating voltage 5.0 kV; trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). PAIm had a porous structure in which communication holes were formed in which adjacent spherical cells were communicated with each other, as shown in FIG.

≪Manufacture of filters with other porous membranes≫
A filter provided with a polyamide (nylon) porous membrane (PAm(d); pore size: 20 nm, manufactured by Pall, Dispo) was prepared.
A filter provided with a polyamide (nylon) porous membrane (PAm(pou); Pall Inc., Point of use) was prepared.

FIG. 3 is a SEM obtained by observing the surface of a polyamide (nylon) porous membrane (PAm(d)) with a scanning electron microscope (accelerating voltage 5.0 kV; trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). It is a statue.
As shown in FIG. 3, the surface state of PAm(d) was different from the form shown in FIG. 2 (that is, a porous structure in which adjacent spherical cells communicate with each other).
The surface state of the polyamide (nylon) porous membrane (PAm(pou)) is also the one shown in FIG. 3, and the one shown in FIG. 2 (that is, the porous structure in which adjacent spherical cells communicate with each other). ) Was a different form.

A filter provided with a polyethylene porous membrane (PEm (pou); pore size 3 nm, manufactured by Entegris, Point of use) was prepared.

FIG. 4 is an SEM image of the surface of a polyethylene porous membrane (PEm(pou)) observed with a scanning electron microscope (accelerating voltage 5.0 kV; trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). ..
As shown in FIG. 4, the surface state of PEm(pou) was different from the form shown in FIG. 2 (that is, a porous structure in which adjacent spherical cells communicate with each other).

<Evaluation of filters>
The following evaluation was performed on the filter including the polyimide porous membrane.

[Imidization rate]
The imidization ratio of the polyimide porous film (PIm(2)) was determined.
Regarding PIm(2), after the heat treatment (re-baking) at the re-baking temperature of 380° C. for 15 minutes shown in Table 1, the imide bond measured by a Fourier transform infrared spectroscopy (FT-IR) device is shown. A value (area ratio) obtained by dividing the area of the peak by the area of the peak representing benzene, which was also measured by the FT-IR apparatus, was obtained, and this was taken as the imidization ratio. The results are shown in Table 1.

[Gurley air permeability]
A sample having a thickness of about 40 μm was cut into a 5 cm square from the polyimide porous membrane (PIm(2)).
A Gurley type densometer (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used to measure the time (seconds) during which 100 mL of air passed through the sample according to JIS P 8117. The results are shown in Table 1.

[Porosity]
The porosity (mass %) of the filter was defined as the ratio of the mass of the fine particles to the total mass of the resin (polyamideimide) and the fine particles used in the manufacture of the filter. The results are shown in Table 1.

[Stress and elongation at break]
Small pieces of size 4 mm×30 mm were cut out from the polyimide porous membrane (PIm(2)) to obtain strip-shaped samples.
The stress at break (MPa; tensile strength) and the elongation at break (%GL) of the sample were evaluated using EZ Test (testing machine, manufactured by Shimadzu Corporation) under the measurement conditions of 5 mm/min. The results are shown in Table 1.

<Production of refined product of resist composition (1)>
(Example 1, Comparative Examples 1 to 3)
A resist solution (1) was prepared by mixing and dissolving the components shown in Table 2, and the resist solution (1) was filtered through each filter to obtain a purified resist composition (solid content concentration: 7. 5% by weight) was produced.

In Table 2, each abbreviation has the following meanings. The numerical value in [] is a compounding amount (part by mass).
(A)-1: A polymer compound represented by the following chemical formula (A)-1. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 10100, and the molecular weight dispersity (Mw/Mn) was 1.62. The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR) was 1/m/n=40/40/20. there were.

(S)-1: Propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether=60/40 (mass ratio) mixed solvent.
(B)-1: An acid generator comprising a compound represented by the following chemical formula (B)-1.
(D)-1: tri-n-octylamine.
(E)-1: salicylic acid.

(Example 1)
The resist solution (1) was filtered through a filter (1) equipped with a polyimide porous membrane (PIm (2)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

(Comparative example 1)
The resist solution (1) was filtered through a filter (2) equipped with a polyamide (nylon) porous membrane (PAm(d)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

(Comparative example 2)
The resist solution (1) was filtered through a filter (3) equipped with a polyamide (nylon) porous membrane (PAm(pou)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

(Comparative example 3)
The resist solution (1) was filtered through a filter (4) equipped with a polyethylene porous membrane (PEm(pou)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

<<Evaluation of purified resist composition products (1)>>
The resist pattern purified product obtained by filtering with a filter in each example was used to form a resist pattern, and the defect was evaluated as follows.

[Formation of resist pattern]
A 12-inch silicon wafer is coated with an organic antireflection film composition "ARC29A" (trade name, manufactured by Brewer Science Co., Ltd.) using a spinner, and baked and dried at 205° C. for 60 seconds on a hot plate to be dried. As a result, an organic antireflection film having a film thickness of 89 nm was formed.
Then, onto the organic antireflection film, the resist composition refined products produced by the production methods of Example 1 and Comparative Examples 1 to 3 were respectively applied using a spinner, and then 110° C. at 60° C. on a hot plate. A pre-baking (PAB) process was performed under the condition of a second, and drying was performed to form a resist film having a film thickness of 80 nm.
Then, an ArF excimer laser (193 nm) was applied to the resist film by an ArF exposure device NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture)=1.07; Cross pole) through a 6% halftone mask. Irradiated selectively.
Then, post-exposure bake (PEB) treatment is performed at 95° C. for 60 seconds, and alkali development is further performed at 23° C. with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 10 seconds. After rinsing with water for 2 seconds, it was shaken off and dried. Then, post baking was performed at 100° C. for 45 seconds.
As a result, in each of the examples, a line and space pattern (LS pattern) having a line width of 45 nm and a pitch of 100 nm was formed.

[Evaluation of defects (number of defects)]
For the obtained LS pattern, the total number of defects in the wafer (total number of defects) was measured using a surface defect observation device (KLA Tencor Co., product name: KLA2371). The results are shown in Table 3. Two wafers were used for each measurement in each example, and the average value was adopted.

From the results shown in Table 3, it can be confirmed that by applying the present invention, the occurrence of defects is further suppressed, and defects such as scum and microbridges are reduced.

<Production of purified resist composition product (2)>
(Examples 2-3, Comparative Examples 4-5)
A resist solution (2) was prepared by mixing and dissolving each component shown in Table 4, and the resist solution (2) was filtered through each filter to obtain a purified resist composition (solid content concentration: 7. 5% by weight) was produced.

In Table 4, each abbreviation has the following meanings. The numerical value in [] is a compounding amount (part by mass).
(A)-2: A polymer compound represented by the following chemical formula (A)-2. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 25,000, and the molecular weight dispersity (Mw/Mn) was 4.5. The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR) is 1/m/n/o=70/5/ It was 20/5.

(A)-3: A polymer compound represented by the following chemical formula (A)-3. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 8500, and the molecular weight dispersity (Mw/Mn) was 2.0. The copolymerization composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR) was 1/m/n=65/15/20. there were.

(S)-2: ethyl lactate.
(B)-2: An acid generator comprising a compound represented by the following chemical formula (B)-2.

Add-1: a compound represented by the following chemical formula (Add)-1.
Add-2: Surfactant. Product name MegaFac XR-104 (manufactured by DIC Corporation).

(Example 2)
The resist composition (2) was filtered with a filter (1) equipped with a polyimide porous membrane (PIm (2)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

(Comparative example 4)
The resist solution (2) was filtered through a filter (2) equipped with a polyamide (nylon) porous membrane (PAm(d)) to obtain a purified resist composition product.
Filtration conditions: Filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ) and temperature 23° C.

(Example 3)
The resist composition purified product obtained in Comparative Example 4 was further filtered through a filter (1) equipped with a polyimide porous membrane (PIm(2)) to obtain a desired resist composition purified product.
Filtration conditions by the filter (1): filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ), temperature 23° C.

(Comparative example 5)
The resist composition purified product obtained in Comparative Example 4 was further filtered through a filter (4) equipped with a polyethylene porous membrane (PEm(pou)) to obtain a desired resist composition purified product. ..
Filtration conditions by the filter (4): filtration pressure 0.3 kgf/cm ² (2.94 N/cm ² ), temperature 23° C.

<<Evaluation of refined resist composition products (2)>>
The resist pattern purified product obtained by filtering with a filter in each example was used to form a resist pattern, and the defect was evaluated as follows.

[Formation of resist pattern]
A known organic antireflective coating composition was applied onto an 8-inch silicon wafer using a spinner, baked on a hot plate at 205° C. for 60 seconds, and dried to give an organic antireflective coating having a film thickness of 120 nm. An antireflection film was formed, and an organic antireflection film-coated substrate was produced.
Then, onto the organic antireflection film-coated substrate, the resist composition purified products produced by the production methods of Examples 2 to 3 and Comparative Examples 4 to 5 were respectively applied using a spinner, and on a hot plate, A pre-baking (PAB) treatment was performed at a temperature of 110° C. for 60 seconds and drying was performed to form a resist film having a thickness of 400 nm.
Then, a KrF excimer laser (248 nm) is selectively applied to the resist film by an exposure apparatus NSR-S205C (manufactured by Nikon Corporation; NA=0.75; 1/2 average) through a mask pattern (binary mask). Irradiated.
Then, post-exposure heating (PEB) treatment is performed at 140° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution (trade name “NMD-3”, Tokyo Ohka Kogyo Co., Ltd.) at 23° C. Alkaline development was performed for 60 seconds.
Then, post baking was performed at 130° C. for 60 seconds.
As a result, in each of the examples, a line and space pattern (LS pattern) having a line width of 200 nm and a pitch of 400 nm was formed.

[Evaluation of defects (number of defects)]
For the obtained LS pattern, the total number of defects in the wafer (total number of defects) was measured using a surface defect observation device (KLA Tencor Co., product name: KLA2371). The results are shown in Table 5. Two wafers were used for each measurement in each example, and the average value was adopted.

From the results shown in Table 5, it can be confirmed that by applying the present invention, the occurrence of defects is further suppressed, and defects such as scum and microbridges are reduced.

1 spherical cell, 1a spherical cell, 1b spherical cell, 5 communication holes, 10 porous film.

Claims (6)

Having a step of filtering the chemical liquid for lithography with a filter,
The method for producing a chemical liquid purified product for lithography, wherein the filter has a porous structure in which adjacent spherical cells communicate with each other. The method for producing a chemical purified product for lithography according to claim 1, wherein the spherical cells in the filter have an average spherical diameter of 50 to 2000 nm. The method for producing a purified chemical liquid product for lithography according to claim 1, wherein the filter comprises a porous film of a thermosetting resin. The chemical solution for lithography is a resist composition containing a base material component (A) whose solubility in a developing solution is changed by the action of an acid and an organic solvent component (S) and having an acid generating ability. Item 4. A method for producing a chemical liquid purified product for lithography according to any one of Items 1 to 3. The method for producing a purified chemical liquid product for lithography according to claim 4, wherein the base material component (A) contains a polymer compound (A1) having a structural unit (ap) containing a polar group. Adjacent spherical cells communicated with a resist composition containing a base material component (A) whose solubility in a developing solution is changed by the action of an acid and an organic solvent component (S) and having an acid generating ability. A step of obtaining a resist composition purified product by filtering with a filter having a porous structure,
A step of forming a resist film on a support using the purified resist composition product,
Exposing the resist film, and
A method for forming a resist pattern, comprising the step of developing the resist film after exposure to form a resist pattern.