Method for producing purified resist composition, method for forming resist pattern, and purified resist composition

Abstract

A method for producing a purified resist composition, comprising step (i) of filtering the resist composition using a filter having a porous structure in which adjacent spherical pores are connected to each other, wherein the filter has a porous membrane, the porous membrane contains at least one resin selected from the group consisting of polyimide and polyamide-imide, and the resist composition contains a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), wherein the content of the organic solvent component (S) is 97% by mass or more.

Description

Technical Field

[0001] The present invention relates to a method for producing a purified resist composition, a resist pattern forming method, and a purified resist composition.

[0002] This application claims priority based on Japanese Patent Application No. 2019-096193 filed in Japan on May 22, 2019, and uses the contents thereof herein. Background Art

[0003] In photolithography, the following steps are performed: for example, a resist film composed of a resist material is formed on a substrate, the resist film is selectively exposed, and a development process is performed to form a resist pattern of a predetermined shape on the resist film. A resist material that changes the exposed portion of the resist film to a property that is soluble in a developer is called a positive type, and a resist material that changes the exposed portion of the resist film to a property that is insoluble in a developer is called a negative type.

[0004] In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, due to the progress of photolithography technology, the miniaturization of patterns has developed rapidly. As a method of miniaturization of patterns, generally speaking, the wavelength of the exposure light source is shortened (higher energy). Specifically, although ultraviolet rays represented by g-rays and i-rays were used in the past, KrF excimer lasers or ArF excimer lasers are now used for mass production of semiconductor elements. In addition, EUV (extreme ultraviolet rays), EB (electron beams), X-rays, etc., which have shorter wavelengths (higher energy) than these excimer lasers, are also being studied.

[0005] Resist materials are required to have photolithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing fine-scale patterns.

[0006] As a resist material satisfying such a requirement, a chemically amplified resist composition containing a base component whose solubility in a developer changes due to the action of an acid and an acid generator component that generates an acid by exposure has been conventionally used.

[0007] As patterns become increasingly miniaturized, resist materials are required to have not only improved lithographic properties but also reduced generation of defects (surface defects).

[0008] Here, the so-called "defects" are, for example, all the defects detected when observing the developed resist pattern from above using a surface defect observation device manufactured by KLA tencor (trade name "KLA"). Such defects include, for example, defects caused by foreign matter and precipitates such as scum (resist residue), bubbles, dust, etc. attached to the surface of the resist pattern after development; defects related to the pattern shape such as bridges between line patterns and filling of holes in contact hole patterns; uneven color of the pattern; and the like.

[0009] In addition, in resist materials, generation of particulate foreign matter over time (one of storage stability) during storage of a resist solution (resist composition in a solution state) is also a problem, and improvement of this problem is desired.

[0010] In the past, in order to remove foreign matter, resist compositions were usually purified by passing them through a filter. However, the method of passing the resist composition through a membrane filter or a depth filter used in the past was not sufficient to suppress the occurrence of defects in the resist pattern after development.

[0011] In order to suppress the generation of defects in the above-mentioned resist pattern and the requirements for the time-dependent properties of foreign matter in the resist material, a method for producing a resist composition has been proposed, which comprises both a step of passing the composition through a nylon filter and a step of passing the composition through a polyolefin resin or fluororesin filter (see Patent Document 1).

[0012] In addition, in the formation of the resist pattern, in addition to the resist composition, various photolithography liquids such as resin solutions containing resins, developers, resist solvents, pre-wetting solvents, etc. are also used. As a method for removing foreign matter (impurities) such as particles mixed in these liquids, a method using a filter has been adopted.

[0013] As patterns become finer, the influence of impurities present in these chemical solutions begins to appear in pattern formation.

[0014] Prior art literature

[0015] Patent Literature

[0016] Patent Document 1: Japanese Patent No. 4637476 Summary of the invention

[0017] Problems to be solved by the invention

[0018] As photolithography technology continues to improve and resist patterns become increasingly miniaturized, when resist patterns with a size of tens to hundreds of nanometers are formed, the generation of scum and micro-bridges after development has become a significant problem. Therefore, a technology that is more superior than ever before and can suppress the generation of defects in resist patterns after development is required.

[0019] On the other hand, as the resist pattern becomes finer, the composition of the resist composition may change before and after the step of passing through the filter, causing problems such as change in pattern size and pattern collapse.

[0020] The present invention is made in view of the above situation, and its subject is to provide a method for manufacturing a purified resist composition that further reduces impurities and is less likely to cause problems such as pattern collapse, a purified resist composition manufactured by the above manufacturing method, and a method for forming a resist pattern formed by the above purified resist composition.

[0021] Means for solving problems

[0022] In order to solve the above-mentioned problems, the present invention adopts the following configuration.

[0023] The first aspect of the present invention is a method for producing a purified product of a resist composition, characterized in that it includes a step (i) of filtering the resist composition using a filter having a porous structure in which adjacent spherical pores are connected to each other, the filter having a porous membrane, the porous membrane containing at least one resin selected from the group consisting of polyimide and polyamideimide, the resist composition containing a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), and the content of the organic solvent component (S) is 97% by mass or more.

[0024] The second embodiment of the present invention is a method for forming a resist pattern, characterized in that it includes the following steps: a step of obtaining a purified resist composition product by utilizing the method for manufacturing a purified resist composition product involved in the first embodiment; a step of forming a resist film on a support using the purified resist composition product; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[0025] The third embodiment of the present invention is a purified product of an anti-etching composition, characterized in that it contains a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), and the number of counted bodies with a size of 0.135 μm or more counted by a light scattering liquid particle counter is less than 1 / mL.

[0026] A fourth aspect of the present invention is a purified resist composition, characterized in that it contains a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), and the content of a metal component (M) selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is less than 1.1 ppb.

[0027] The fifth embodiment of the present invention is a method for forming a resist pattern, characterized in that it includes the following steps: a step of forming a resist film on a support body using a purified product of the resist composition involved in the third embodiment or the fourth embodiment; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[0028] Effects of the Invention

[0029] According to the present invention, there can be provided a method for producing a purified resist composition with further reduced impurities and less prone to problems such as pattern collapse, a purified resist composition produced by the above-mentioned production method, and a method for forming a resist pattern formed by the above-mentioned purified resist composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] [ Figure 1 ] is a diagram schematically showing an embodiment of the interconnecting pores constituting the polyimide-based resin porous membrane. DETAILED DESCRIPTION

[0031] In the present specification and the present claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity.

[0032] Unless otherwise specified, "alkyl" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.

[0033] Unless otherwise specified, the term "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups.

[0034] The "haloalkyl group" is a group in which a part or all of the hydrogen atoms of an alkyl group are substituted with halogen atoms, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0035] The "fluoroalkyl group" or "fluoroalkylene group" refers to a group in which a part or all of the hydrogen atoms of an alkyl group or an alkylene group are substituted with fluorine atoms.

[0036] The "structural unit" refers to a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

[0037] When it is described as "may have a substituent" or "may have a substituent", it includes the case where a hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH 2 -) in these two cases.

[0038] “Exposure” is a concept that covers all exposure to radiation.

[0039] The "structural unit derived from acrylic acid ester" refers to a structural unit formed by cleavage of the ethylenic double bond of acrylic acid ester.

[0040] "Acrylate" is acrylic acid (CH 2 =CH-COOH)) with an organic group replacing the hydrogen atom at the carboxyl terminal.

[0041] The hydrogen atom bonded to the carbon atom at the α position of the acrylate may be substituted with a substituent. α0 ) is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, etc. In addition, a substituent (R α0 ) is substituted with a substituent containing an ester bond, the substituent (R α0 ) is substituted with a hydroxyalkyl group or a group modifying the hydroxyl group. It should be noted that, unless otherwise specified, the carbon atom at the α position of the acrylate refers to the carbon atom to which the carbonyl group of acrylic acid is bonded.

[0042] Hereinafter, an acrylate in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate. In addition, acrylates and α-substituted acrylates may be collectively referred to as “(α-substituted) acrylates”.

[0043] The "structural unit derived from acrylamide" refers to a structural unit formed by cleavage of the ethylenic double bond of acrylamide.

[0044] In the case of acrylamide, the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. It should be noted that, unless otherwise specified, the carbon atom at the α position of acrylamide refers to the carbon atom bonded to the carbonyl group of acrylamide.

[0045] Examples of the substituent that replaces the hydrogen atom bonded to the carbon atom at the α-position of acrylamide include the groups exemplified as the substituent at the α-position in the above-mentioned α-substituted acrylate (substituent (R α0))same group.

[0046] The "structural unit derived from hydroxystyrene" refers to a structural unit formed by cleavage of the olefinic double bonds of hydroxystyrene. The "structural unit derived from a hydroxystyrene derivative" refers to a structural unit formed by cleavage of the olefinic double bonds of a hydroxystyrene derivative.

[0047] "Hydroxystyrene derivatives" refer to compounds in which the hydrogen atom at the α position of hydroxystyrene is replaced by other substituents such as alkyl groups, halogenated alkyl groups, and their derivatives. As their derivatives, there are compounds in which the hydrogen atom of the hydroxyl group of hydroxystyrene in which the hydrogen atom at the α position may be substituted by a substituent is replaced by an organic group; compounds in which a substituent other than a hydroxyl group is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α position may be substituted by a substituent, and the like. In addition, unless otherwise specified, the α position (carbon atom at the α position) refers to the carbon atom bonded to the benzene ring.

[0048] Examples of the substituent that replaces the hydrogen atom at the α-position of the hydroxystyrene include the same groups as exemplified as the substituent at the α-position in the above-mentioned α-substituted acrylate.

[0049] The "structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative" refers to a structural unit constituted by cleavage of the ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.

[0050] "Vinylbenzoic acid derivatives" are a concept including compounds in which the hydrogen atom at the α position of vinylbenzoic acid is substituted by other substituents such as alkyl groups, halogenated alkyl groups, and their derivatives. As their derivatives, there can be cited compounds in which the hydrogen atom of the carboxyl group of vinylbenzoic acid in which the hydrogen atom at the α position may be substituted by a substituent is substituted by an organic group; compounds in which a substituent other than a hydroxyl group and a carboxyl group are bonded to the benzene ring of vinylbenzoic acid in which the hydrogen atom at the α position may be substituted by a substituent, and the like. In addition, unless otherwise specified, the α position (carbon atom at the α position) refers to the carbon atom bonded to the benzene ring.

[0051] "Styrene derivatives" are a concept including compounds in which the hydrogen atom at the α position of styrene is substituted by other substituents such as alkyl groups, halogenated alkyl groups, and their derivatives. As their derivatives, there can be cited substances in which a substituent is bonded to the benzene ring of hydroxystyrene in which the hydrogen atom at the α position may be substituted by a substituent. It should be noted that, unless otherwise specified, the α position (the carbon atom at the α position) refers to the carbon atom bonded to the benzene ring.

[0052] The "structural unit derived from styrene" and "structural unit derived from a styrene derivative" refer to a structural unit constituted by cleavage of an ethylenic double bond of styrene or a styrene derivative.

[0053] The alkyl group as the substituent at the α position is preferably a linear or branched alkyl group, and specific examples thereof include alkyl groups having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl).

[0054] In addition, the haloalkyl group as a substituent at the α position specifically includes a group obtained by replacing a part or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α position" with a halogen atom. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. can be mentioned, and a fluorine atom is particularly preferred.

[0055] In addition, the hydroxyalkyl group as a substituent at the α position specifically includes a group obtained by replacing a part or all of the hydrogen atoms of the above-mentioned "alkyl group as a substituent at the α position" with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0056] The "polyimide-based resin" refers to one or both of polyimide and polyamideimide. Each of the polyimide and polyamideimide may have at least one functional group selected from the group consisting of a carboxyl group, a salt-type carboxyl group, and an -NH- bond.

[0057] A porous film containing at least one of polyimide and polyamideimide is sometimes referred to as a "polyimide-based resin porous film". A porous film containing polyimide is sometimes referred to as a "polyimide porous film". A porous film containing polyamideimide is sometimes referred to as a "polyamideimide porous film".

[0058] In this specification and claims, there is a structure of an asymmetric carbon, and there may be an enantiomer or a diastereomer, depending on the structure represented by the chemical formula. In this case, these isomers are represented representatively by one chemical formula. These isomers may be used alone or as a mixture.

[0059] (Method for producing purified resist composition)

[0060] The method for producing a purified product of a resist composition according to the first embodiment of the present invention comprises a step (i) of filtering using a filter having a porous structure in which adjacent spherical pores are connected to each other. The filter comprises a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamide-imide. The resist composition comprises a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), wherein the content of the organic solvent component (S) is 97% by mass or more.

[0061] By performing step (i), impurities such as particles are removed from the resist composition, thereby obtaining a highly purified resist composition.

[0062] According to the above-mentioned manufacturing method, in particular, by using a filter having a porous structure in which adjacent spherical pores are interconnected and having a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamide-imide, high-polarity components and polymers that were previously difficult to remove can be fully removed from the anti-etching composition, wherein the high-polarity polymers are specifically removed.

[0063] In addition, in step (i), metal components as impurities are also fully removed from the resist composition. The metal components are sometimes originally contained in the components constituting the resist composition, and sometimes mixed in from the pipes, joints, etc. of the manufacturing device and the like in the transfer path of the resist composition. In step (i), for example, iron, nickel, zinc, chromium, etc. that are easily mixed in from the manufacturing device and the like can be effectively removed.

[0064] <Process (i)>

[0065] The step (i) is a step of filtering the resist composition using a filter having a porous structure in which adjacent spherical cells communicate with each other.

[0066] Filter

[0067] The filter used in this step has a porous structure in which adjacent spherical cells communicate with each other.

[0068] For example, the filter may be formed solely of a porous membrane in which adjacent spherical cells communicate with each other, or another filter material may be used together with the porous membrane.

[0069] Examples of other filter materials include nylon membranes, polytetrafluoroethylene membranes, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) membranes, and modified membranes thereof.

[0070] As for the filter, in order to separate the supply liquid of the resist composition from the filtrate without mixing, it is preferred to seal the area of ​​the porous membrane before and after the liquid is passed. As a method for the sealing, for example, it can be cited: a method of processing the porous membrane by bonding based on light (UV) curing or bonding based on heat (including bonding based on anchoring effect (thermal fusion, etc.)) or bonding using an adhesive, etc.; or, a method of bonding the porous membrane to other filter materials by embedding method, etc. As the filter, a filter having the above-mentioned porous membrane in an outer container formed by a thermoplastic resin (polyethylene, polypropylene, PFA, polyether sulfone (PES), polyimide, polyamide-imide, etc.) can also be cited.

[0071] In the filter, the porous membrane may be in a planar shape or in a tubular shape formed by closing opposite sides of the porous membrane. The surface of the tubular porous membrane is preferably pleated from the viewpoint of increasing the area in contact with the supply liquid.

[0072] ·About "a porous membrane in which adjacent spherical cells communicate with each other"

[0073] The “porous membrane in which adjacent spherical cells communicate with each other” included in the filter has communicating holes in which adjacent spherical cells communicate with each other.

[0074] The communicating pores are formed by the individual pores (cells) that impart porosity to the porous membrane. The pores include pores in which substantially the entire inner surface of the pore is a curved surface, and also include pores in other shapes.

[0075] In this specification, a hole whose almost entire inner surface is a curved surface is referred to as a "spherical cell" or a "substantially spherical cell". In the case of a spherical cell (substantially spherical cell), the inner surface of the hole forms a substantially spherical space. When the microparticles used in the method for producing a porous polyimide resin film described later are substantially spherical, spherical cells are easily formed.

[0076] The term "substantially spherical" includes a true sphere, but is not necessarily limited to a true sphere, and includes a substantially spherical shape. The term "substantially spherical" means that the true sphericity defined by the major diameter / minor diameter, represented by the value obtained by dividing the major diameter of the particle by the minor diameter, is within 1±0.3. The above-mentioned true sphericity of the spherical cell herein is preferably within 1±0.1, and more preferably within 1±0.05.

[0077] In the porous membrane in which adjacent spherical cells communicate with each other, at least a part of the communicating pores are formed by the adjacent spherical cells.

[0078] Figure 1 One embodiment of the continuous pores constituting the porous membrane is schematically shown.

[0079] In the porous membrane of the present embodiment, substantially the entire inner surface of each of the spherical cells 1 a and the spherical cells 1 b is a curved surface, forming a substantially spherical space.

[0080] The spherical cells 1a and 1b are adjacent to each other, and a communicating hole 5 is formed to penetrate the overlapping portion Q of the adjacent spherical cells 1a and 1b. The filtered object flows through the communicating hole 5, for example, in the direction from the spherical cells 1a to the spherical cells 1b (direction of arrow).

[0081] In the porous membrane having a structure in which adjacent spherical cells communicate with each other, it is preferred that a plurality of pores (spherical cells, communicating pores) are connected to form a flow path for the filtration object as a whole.

[0082] The above-mentioned "flow path" is usually formed by connecting each "hole" and / or "connecting hole" to each other. Each hole is formed by, for example, removing each particle present in the polyimide resin-microparticle composite film in a subsequent process in the method for producing a polyimide resin porous film described later. In addition, the connecting hole is formed by removing the particles in the polyimide resin-microparticle composite film at the portion where each particle is in contact with each other in the subsequent process in the method for producing a polyimide resin porous film described later.

[0083] In the porous membrane, a spherical pore chamber and a communicating hole connected to each other with adjacent spherical pore chambers are formed, and the degree of porosity is improved. In addition, in the porous membrane, the spherical pore chamber or the communicating hole opens on the surface of the porous membrane, and the communicating hole opened on one surface connects the inside of the porous membrane, and opens on the other (back side) surface to form a flow path through which a fluid can pass from the inside of the porous membrane. Moreover, according to the porous membrane, by allowing the filtered object to flow through the above-mentioned flow path, foreign matter contained in the filtered object is removed from the filtered object before filtration.

[0084] Since the porous membrane has a flow path formed by connecting holes inside, and the connecting holes are formed by spherical pores having curved surfaces on the inner surface, the surface area of ​​the inner surface of the spherical pores is large. Therefore, the filter object can not only pass through the inside of the porous membrane, but also increase the contact frequency with the inner surface of the spherical pores while passing through the porous membrane while contacting the curved surface of each spherical pore, so that foreign matter present in the filter object is adsorbed by the inner surface of the spherical pores, and the foreign matter is easily removed from the filter object.

[0085] The porous membrane preferably has a structure in which spherical cells having an average spherical diameter of 10 to 500 nm are connected to each other. The average spherical diameter of the spherical cells is more preferably 30 to 500 nm, and even more preferably 50 to 400 nm.

[0086] The average spherical diameter of the spherical pore chamber refers to the average value of the diameter of the communicating pores formed by two adjacent spherical pore chambers. The average spherical diameter of the spherical pore chamber is a value obtained by measuring the diameter of the pores using a Perm porometer (e.g., Polar Materials) and a bubble point method. Specifically, it can be obtained using the same method as the average pore diameter in the porous membrane described later.

[0087] The flow paths inside the "porous membrane in which adjacent spherical pores are connected to each other" may include, in addition to the above-mentioned spherical pores and the connecting holes between the above-mentioned spherical pores, holes of other shapes or connecting holes containing the same.

[0088] In addition, the spherical cell may further have a recessed portion on its inner surface. The recessed portion may form a hole, for example, which is open to the inner surface of the spherical cell and has a smaller hole diameter than the spherical cell.

[0089] The “porous membrane in which adjacent spherical pores are interconnected” may include a membrane containing resin, and may be substantially formed only by resin. Examples include a membrane in which preferably 95% by mass or more, more preferably 98% by mass or more, and further preferably 99% by mass or more of the entire porous membrane is resin.

[0090] The porous film contains a polyimide resin. The porous film containing a polyimide resin is excellent in foreign matter removal performance, strength, and stability of photolithography characteristics before and after filtration.

[0091] The porous membrane contains at least one of polyimide and polyamideimide as a resin, preferably contains at least polyimide. The porous membrane may contain only polyimide as a resin, or may contain only polyamideimide as a resin, preferably contains only polyimide.

[0092] As the “porous film in which adjacent spherical cells communicate with each other”, it is particularly preferred that 95% by mass or more of the entire porous film is at least one of polyimide and polyamideimide.

[0093] Hereinafter, a porous film (polyimide-based resin porous film) containing a polyimide-based resin as a resin and having adjacent spherical cells communicating with each other will be described.

[0094] ··Polyimide resin porous membrane

[0095] The polyimide-based resin may have at least one functional group selected from the group consisting of a carboxyl group, a salt-type carboxyl group, and an -NH- bond.

[0096] As the polyimide resin, a polyimide resin having the above functional group other than the main chain terminal is preferred. As a preferred polyimide resin having the above functional group other than the main chain terminal, for example, polyamic acid can be mentioned.

[0097] In this specification, "salt-type carboxyl group" refers to a group in which the hydrogen atom in the carboxyl group is replaced by a cationic component. The so-called "cationic component" may be a cation itself in a completely ionized state, or may be a cation in a state of being ionized with -COO. -A cationic constituent that is ionically bonded and is substantially uncharged may also be a cationic constituent that has a partial charge in an intermediate state between the two.

[0098] When the “cation component” is an M ion component composed of an n-valent metal M, the cation itself is represented by M n+ , as a cation component, is composed of "-COOM 1 / n "M" in " 1 / n " indicates the elements.

[0099] The "cation component" includes cations when the compounds mentioned below as the compounds contained in the etching solution undergo ion dissociation. Representative examples include ion components or organic alkali ion components. For example, when the alkali metal ion component is a sodium ion component, the cation itself is a sodium ion (Na + ), as a cation constituent, it is an element represented by "Na" in "-COONa". As a cation constituent having a partial charge, it is Na δ+ .

[0100] The cationic component is not particularly limited, and examples thereof include: inorganic components; NH 4 + 、N(CH 3 ) 4 + As inorganic components, for example, alkali metals such as Li, Na, and K; and metal elements such as alkaline earth metals such as Mg and Ca can be cited. As organic components, for example, organic alkali ion components can be cited. As organic alkali ion components, NH 4 + , such as NR 4 + (All four Rs represent organic groups, which may be the same or different.) A quaternary ammonium cation represented by the above organic group 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 + wait.

[0101] The state of the cationic component in the salt-type carboxyl group is not particularly limited, and generally depends on the environment in which the polyimide resin exists, such as an aqueous solution, an organic solvent, or a dry environment. When the cationic component is a sodium ion component, for example, in an aqueous solution, it may dissociate into -COO - and Na + If it is in an organic solvent or dry, there is a high possibility that -COONa will not dissociate.

[0102] The polyimide resin may have at least one functional group selected from the group consisting of a carboxyl group, a salt-type carboxyl group, and -NH-bonds. In the case of having at least one of these, usually, it has both a carboxyl group and / or a salt-type carboxyl group and an -NH-bond. With respect to the polyimide resin, when it comes to a carboxyl group and / or a salt-type carboxyl group, it may have only a carboxyl group, it may have only a salt-type carboxyl group, or it may have both a carboxyl group and a salt-type carboxyl group. With respect to the ratio of the carboxyl group to the salt-type carboxyl group possessed by the polyimide resin, even if it is the same polyimide resin, for example, it may vary according to the environment in which the polyimide resin exists, and it may also be affected by the concentration of the cationic component.

[0103] In the case of polyimide, the total number of moles of the carboxyl group and the salt-type carboxyl group of the polyimide resin is usually equimolar to the -NH- bond.

[0104] In particular, in the method for producing a porous polyimide membrane described below, when carboxyl groups and / or salt-type carboxyl groups are formed from a portion of imide bonds in the polyimide, -NH- bonds are substantially formed simultaneously, and the total number of moles of the formed carboxyl groups and salt-type carboxyl groups is equimolar to the formed -NH- bonds.

[0105] In the method for producing a porous polyamideimide membrane, the total molar number of carboxyl groups and salt-type carboxyl groups in the polyamideimide is not necessarily equimolar to the -NH- bond and depends on the conditions of chemical etching in the etching (imide bond opening) step described later.

[0106] The polyimide-based resin preferably has at least one structural unit selected from the group consisting of structural units represented by the following general formulae (1) to (4), for example.

[0107] In the case of a polyimide, it is preferred that the polyimide has at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).

[0108] In the case of a polyamideimide, it preferably has at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (3) and a structural unit represented by the following general formula (4).

[0109] [Chemical formula 1]

[0110]

[0111] [Chemical formula 2]

[0112]

[0113] In the above formulas (1) to (3), X 1 ~X 4They may be the same as or different from each other and may be hydrogen atoms or cationic components.

[0114] R Ar is an aryl group, and examples thereof include R bonded to the carbonyl group in each of the structural units represented by the formula (5) constituting the polyamic acid (poly amicacid) described later or the structural units represented by the formula (6) constituting the aromatic polyimide. Ar The same groups as those represented by the aryl groups.

[0115] Y 1 ~Y 4 Each independently represents a divalent residue after removing an amino group from a diamine compound, and includes R′ bonded to N in each of the structural units represented by formula (5) constituting a polyamic acid or the structural units represented by formula (6) constituting an aromatic polyimide described later. Ar The same groups as those represented by the arylene group.

[0116] The polyimide resin may be a polyimide having an imide bond (-N[-C(=O)] 2 ) is partially ring-opened, thereby respectively having, in the case of polyimide, each structural unit represented by the above-mentioned general formula (1) or general formula (2), and in the case of polyamide-imide, having a structural unit represented by the above-mentioned general formula (3).

[0117] The porous polyimide resin film may contain a polyimide resin having at least one functional group selected from the group consisting of a carboxyl group, a salt-type carboxyl group, and a -NH- bond by ring-opening a part of imide bonds.

[0118] The unchanged rate when a part of the imide bonds are opened can be obtained by the following steps (1) to (3).

[0119] Step (1): With respect to a porous polyimide resin membrane to which the etching (opening of imide bonds) step described later is not performed (wherein, in the case where the varnish used to prepare the porous membrane contains polyamic acid, in the step of calcining the uncalcined composite membrane, a porous polyimide resin membrane in which the imidization reaction is substantially completed is formed), a value (X01) represented by the following value is calculated, wherein the value is the value obtained by dividing the area of ​​the peak representing the imide bonds measured by a Fourier transform infrared spectrometer (FT-IR) device by the area of ​​the peak representing benzene measured by the same FT-IR device.

[0120] Step (2): For a polyimide resin porous membrane obtained using the same polymer (varnish) as the porous membrane for calculating the above-mentioned value (X01), and after the etching (opening of imide bonds) step described later, calculate the value (X02) represented by the following value, which is the value obtained by dividing the area of ​​the peak representing the imide bond measured by a Fourier transform infrared spectrometer (FT-IR) device by the area of ​​the peak representing benzene measured by the same FT-IR device.

[0121] Step (3): Calculate the constant rate using the following formula.

[0122] Unchanged rate (%) = (X02) ÷ (X01) × 100

[0123] The unchanged rate in the polyimide resin porous film is preferably 60% or more, more preferably 70 to 99.5%, and even more preferably 80 to 99%. In the case of a porous film containing polyamideimide, the unchanged rate can be 100% because it contains -NH- bonds.

[0124] In the case of a porous polyimide film, the value obtained by dividing the area of ​​the peak representing imide bonds measured by an FT-IR apparatus by the area of ​​the peak representing benzene measured by the same FT-IR apparatus is referred to as the “imidization ratio”.

[0125] The imidization ratio associated with the value (X02) obtained in the above step (2) is preferably 1.2 or more, more preferably 1.2 to 2, 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. In addition, the imidization ratio associated with the value (X01) obtained in the above step (1) is preferably 1.5 or more.

[0126] The larger the imidization ratio is, the greater the number of imide bonds is, that is, the smaller the number of ring-opened imide bonds is.

[0127] ··Method for producing porous polyimide resin membrane

[0128] The porous polyimide resin film can be produced by a method including a step of forming carboxyl groups and / or salt-type carboxyl groups from a part of imide bonds in polyimide and / or polyamide-imide (hereinafter referred to as “etching step”).

[0129] In the etching process, when a carboxyl group and / or a salt-type carboxyl group is formed from a part of the imide bond, a -NH- bond is also substantially formed at the same time in a theoretically equimolar amount to these groups.

[0130] When the resin contained in the polyimide-based resin porous membrane is substantially formed of polyamide-imide, the porous membrane already has -NH- bonds even without being subjected to the etching step, and exhibits good adsorption force for foreign matter in the filtration object. In this case, the etching step is not necessarily required from the perspective of not having to particularly slow down the flow rate of the filtration object, but it is preferably provided from the perspective of more effectively achieving the purpose of the present invention.

[0131] As a method for producing a porous polyimide resin film, it is preferred to prepare a molded film mainly composed of polyimide and / or polyamideimide (hereinafter, sometimes simply referred to as a "polyimide resin molded film") and then perform an etching step.

[0132] The polyimide resin molded film to be subjected to the etching step may be porous or non-porous.

[0133] The form of the polyimide resin molded film is not particularly limited, but is preferably a thin film or the like, and more preferably a porous and thin film or the like, from the viewpoint of increasing the porosity of the obtained polyimide resin porous film.

[0134] The polyimide resin molded film may be non-porous when the etching step is performed as described above. In this case, it is preferable to make the film porous after the etching step.

[0135] As a method for making a polyimide resin molded film porous before or after an etching process, a method preferably includes a [particle removal] step of removing the particles from a composite film of polyimide and / or polyamideimide and particles (hereinafter referred to as "polyimide resin-particle composite film") to make the film porous.

[0136] As a method for producing a porous polyimide resin film, the following production method (a) or production method (b) may be mentioned.

[0137] Manufacturing method (a): A method of subjecting a composite film of polyimide and / or polyamide-imide and microparticles to an etching step before the step of [removing microparticles]

[0138] Production method (b): After the step of [removing fine particles], a method of performing an etching step on the polyimide resin molded film made porous by the step.

[0139] Among these, the latter production method (b) is preferred because the porosity of the obtained polyimide-based resin porous film can be further increased.

[0140] Hereinafter, an example of a method for producing a porous polyimide resin film will be described.

[0141] [Preparation of varnish]

[0142] The varnish is prepared by mixing a fine particle dispersion obtained by preliminarily dispersing fine particles in an organic solvent with polyamic acid, polyimide or polyamideimide at an arbitrary ratio, or by polymerizing tetracarboxylic dianhydride and diamine in the fine particle dispersion to obtain polyamic acid or further imidizing the polyamic acid to obtain polyimide.

[0143] The viscosity of the varnish is preferably 300 to 2000 cP (0.3 to 2 Pa·s), and more preferably 400 to 1800 cP (0.4 to 1.8 Pa·s). When the viscosity of the varnish is within the above range, a more uniform film can be formed.

[0144] The viscosity of the varnish can be measured at a temperature of 25° C. using an E-type rotational viscometer.

[0145] In the above-mentioned varnish, when it is fired (fired and dried in any case) to form a polyimide resin-microparticle composite film, the resin microparticles are mixed with polyamic acid or polyimide or polyamide-imide in a manner such that the ratio of microparticles / polyimide resin is preferably 1 to 4 (mass ratio), more preferably 1.1 to 3.5 (mass ratio).

[0146] In addition, when a polyimide resin-microparticle composite film is prepared, the microparticles are mixed with polyamic acid or polyimide or polyamide-imide in such a manner that the volume ratio of microparticles / polyimide resin is preferably 1.1 to 5, more preferably 1.1 to 4.5. When the mass ratio or volume ratio is above the preferred lower limit of the above range, holes of appropriate density can be easily obtained as a porous film, and when it is below the preferred upper limit of the above range, problems such as increase in viscosity and cracks in the film are not likely to occur, and stable film formation can be achieved.

[0147] In addition, in this specification, the volume ratio shows the value at 25 degreeC.

[0148] ···particle

[0149] The material of the fine particles is not particularly limited as long as it is insoluble in the organic solvent used in the varnish and can be selectively removed after film formation.

[0150] As a material of the fine particles, for example, silicon dioxide (SiO 2 ), titanium oxide, aluminum oxide (Al 2 O 3), metal oxides such as calcium carbonate, etc. As organic materials, for example, organic polymers such as high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene, acrylic resins (methyl methacrylate, isobutyl methacrylate, polymethyl methacrylate (PMMA)), epoxy resins, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polyether, polyethylene, etc. can be cited.

[0151] Among these, silica such as colloidal silica is preferred as the inorganic material because it is easy to form micropores having a curved inner surface in the porous film. Acrylic resins such as PMMA are preferred as the organic material.

[0152] As the resin particles, for example, they can be selected without particular limitation from common linear polymers and known depolymerizable polymers according to the purpose. Common linear polymers are polymers whose molecular chains are randomly cut during thermal decomposition. Depolymerizable polymers are polymers that decompose into monomers during thermal decomposition. Any polymer decomposes into monomers, low molecular weight bodies, or CO 2 when heated. 2 , thereby being able to be removed from the polyimide resin film.

[0153] Among the depolymerizable polymers, homopolymers of methyl methacrylate or isobutyl methacrylate (polymethyl methacrylate or polyisobutyl methacrylate) having a low thermal decomposition temperature, or copolymers containing them as a main component are preferred from the viewpoint of handling during pore formation.

[0154] The decomposition temperature of the resin 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 in the varnish, and the range of selection of the calcination conditions of the polyimide resin becomes wider. When the decomposition temperature is 320° C. or lower, only the resin particles can be easily eliminated without causing thermal damage to the polyimide resin.

[0155] The microparticles preferably have a high sphericity because the inner surfaces of the pores in the formed porous film are easily curved. The particle size (average diameter) of the microparticles used is, for example, preferably 50 to 2000 nm, more preferably 200 to 1000 nm.

[0156] If the average diameter of the microparticles is within the above range, when the filtered object is passed through the polyimide resin porous membrane obtained by removing the microparticles, the filtered object can be uniformly contacted with the inner surface of the pores in the porous membrane, and foreign matter contained in the filtered object can be efficiently adsorbed.

[0157] The particle size distribution index (d25 / d75) of the fine particles is preferably 1-6, more preferably 1.6-5, and even more preferably 2-4.

[0158] By making the particle size distribution index greater than the preferred lower limit of the above range, the microparticles can be efficiently filled into the porous membrane, so that a flow path is easily formed and the flow rate is improved. In addition, holes of different sizes are easily formed to generate different convections, and the adsorption rate of foreign matter is further improved.

[0159] It should be noted that d25 and d75 are values ​​of particle diameters at which the cumulative frequencies of the particle size distribution are 25% and 75%, respectively, and in this specification, d25 refers to the larger particle diameter.

[0160] In the [Film formation of unfired composite film] described later, when the unfired composite film is formed into two layers, the microparticles (B1) used in the first varnish and the microparticles (B2) used in the second varnish may be the same microparticles or different microparticles. In order to make the pores on the side in contact with the substrate denser, it is preferred that the particle size distribution index of the microparticles (B1) is smaller than that of the microparticles (B2), or the same. Alternatively, it is preferred that the spherical ratio of the microparticles (B1) is smaller than that of the microparticles (B2), or the same. In addition, it is preferred that the particle size (average diameter) of the microparticles (B1) is smaller than that of the microparticles (B2), and it is particularly preferred that the microparticles (B1) are 100 to 1000 nm (more preferably 100 to 600 nm) and the microparticles (B2) are 500 to 2000 nm (more preferably 700 to 2000 nm). By using particles (B1) having a smaller particle size than particles (B2), the opening ratio of the pores on the surface of the obtained polyimide resin porous membrane is increased, and the diameter can be made uniform. Moreover, for the polyimide resin porous membrane as a whole, the strength of the porous membrane can be improved compared with the case of using particles (B1) alone.

[0161] In the present embodiment, for the purpose of making the particles uniformly dispersed in the varnish, a dispersant can be further added together with the above-mentioned particles. By further adding a dispersant, polyamic acid or polyimide or polyamide-imide can be more evenly mixed with the particles, and the particles can also be evenly distributed in the unfired composite film. As a result, dense openings can be set on the surface of the finally obtained polyimide-based resin porous membrane, and a connecting hole that connects the surface and the back of the porous membrane can be efficiently formed in a manner that improves the air permeability of the polyimide-based resin porous membrane.

[0162] The above-mentioned dispersant is not particularly limited, and a known dispersant can be used. Examples of the above-mentioned dispersant include: anionic surfactants such as coconut fatty acid salts, sulfated castor oil salts, dodecyl sulfate salts, polyoxyalkylene allyl phenyl ether sulfates, alkylbenzene sulfonic acids, alkylbenzene sulfonates, alkyl diphenyl ether disulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, isopropyl phosphates, polyoxyethylene alkyl ether phosphate salts, and polyoxyethylene allyl phenyl ether phosphate salts; cationic surfactants such as oleylamine acetate, lauryl pyridinium chloride, cetyl pyridinium chloride, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, and didecyl dimethyl ammonium chloride; coconut oil alkyl dimethyl amine oxide, fatty acid amide propyl dimethyl amine oxide, alkyl polyaminoethyl glycine hydrochloride, amido betaine type surfactants, propylamine Acid type surfactants, amphoteric surfactants such as lauryl iminodipropionic acid; nonionic surfactants of polyoxyethylene primary alkyl ether or polyoxyalkylene secondary alkyl ether such as polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene lauryl amine, polyoxyethylene oleyl amine, polyoxyethylene polystyryl phenyl ether, polyoxyalkylene polystyryl phenyl ether, polyoxyethylene nonionic surfactants of polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, sorbitan laurate, polyoxyethylene sorbitan laurate, fatty acid diethanolamide, etc.; fatty acid alkyl esters such as octyl stearate and trimethylolpropane tricaprate; polyether polyols such as polyoxyalkylene butyl ether, polyoxyalkylene oleyl ether, trimethylolpropane tri(polyoxyalkylene) ether. The above dispersants can be used alone or in combination of two or more.

[0163] ···Polyamide acid

[0164] As a polyamic acid which can be used in this embodiment, the polyamic acid obtained by polymerizing arbitrary tetracarboxylic dianhydride and diamine is mentioned.

[0165] ····Tetracarboxylic dianhydride

[0166] Tetracarboxylic dianhydride can be appropriately selected from tetracarboxylic dianhydrides conventionally used as a synthetic raw material for polyamic acid.

[0167] The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride.

[0168] Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 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'-benzophenonetetracarboxylic dianhydride, bis(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-(isophenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-diphthalic anhydride fluorene, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, etc.

[0169] Examples of the aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and 1,2,3,4-cyclohexane tetracarboxylic dianhydride.

[0170] Among the above, aromatic tetracarboxylic dianhydrides are preferred from the viewpoint of heat resistance of the obtained polyimide resin, and 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferred from the viewpoint of price and availability.

[0171] The tetracarboxylic dianhydride may be used alone or in combination of two or more.

[0172] ····Diamine

[0173] The diamine can be appropriately selected from the diamines that have been used as the synthetic raw materials of polyamic acid. The diamine can be an aromatic diamine or an aliphatic diamine, but from the perspective of the heat resistance of the resulting polyimide resin, an aromatic diamine is preferred. The diamine can be used alone or in combination of two or more.

[0174] Examples of the aromatic diamine include diamino compounds to which 1 or 2 to 10 phenyl groups are bonded. Specific examples of the aromatic diamine include phenylenediamine or derivatives thereof, diaminobiphenyl compounds or derivatives thereof, diaminodiphenyl compounds or derivatives thereof, diaminotriphenyl compounds or derivatives thereof, diaminonaphthalene or derivatives thereof, aminophenylaminoindanes or derivatives thereof, diaminotetraphenyl compounds or derivatives thereof, diaminohexaphenyl compounds or derivatives thereof, and Cardo-type fluorenediamine derivatives.

[0175] As the phenylenediamine, meta-phenylenediamine and para-phenylenediamine are preferred. As the phenylenediamine derivative, there can be mentioned diamines to which an alkyl group such as a methyl group or an ethyl group is bonded, for example, 2,4-diaminotoluene, 2,4-triphenylenediamine, and the like.

[0176] The diaminobiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via a phenyl group. Examples of the diaminobiphenyl compound include 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

[0177] The diaminodiphenyl compound is a compound formed by two aminophenyl groups bonded to each other through phenyl groups via other groups. As other groups, ether bonds, sulfonyl bonds, thioether bonds, alkylene groups or their derivative groups, imino bonds, azo bonds, phosphine oxide bonds, amide bonds, ureido bonds, etc. can be cited. The carbon number of the alkylene group is preferably about 1 to 6, and its derivative group is a group obtained by replacing more than one hydrogen atom of the alkylene group with a halogen atom or the like.

[0178] 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)-1-pentene, and 4-methyl-2,4-bis(p-aminophenyl)-1-pentene. (p-aminophenyl)-2-pentene, iminodiphenylamine, 4-methyl-2,4-bis(p-aminophenyl)pentane, bis(p-aminophenyl)phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenyl urea, 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.

[0179] The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are bonded to each other through other groups. Examples of the other groups include the same groups as those in the diaminodiphenyl compound.

[0180] 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.

[0181] Examples of the diaminonaphthalene include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

[0182] Examples of the aminophenylaminoindan include 5- or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindan and the like.

[0183] Examples of the diaminotetraphenyl compound include 4,4′-bis(p-aminophenoxy)biphenyl, 2,2′-bis[p-(p-aminophenoxy)phenyl]propane, 2,2′-bis[p-(p-aminophenoxy)biphenyl]propane, and 2,2′-bis[p-(m-aminophenoxy)phenyl]benzophenone.

[0184] Examples of the Cardo-type fluorene diamine derivative include 9,9-dianiline fluorene and the like.

[0185] As the aliphatic diamine, for example, an aliphatic diamine having about 2 to 15 carbon atoms is preferred, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

[0186] In addition, the diamine may be a compound in which a hydrogen atom is substituted with at least one substituent selected from the group consisting of a halogen atom, a methyl group, a methoxy group, a cyano group, and a phenyl group.

[0187] Among the above, preferred diamines are phenylenediamine, phenylenediamine derivatives, and diaminodiphenyl compounds. Among them, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, and 4,4'-diaminodiphenyl ether are particularly preferred in terms of price and availability.

[0188] The method for producing the polyamic acid is not particularly limited, and a known method such as a method of reacting any tetracarboxylic dianhydride and diamine in an organic solvent can be used.

[0189] The reaction of 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 can be used alone or in combination of two or more.

[0190] Examples of the organic solvent used in the reaction of tetracarboxylic dianhydride and diamine include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N',N'-tetramethylurea; lactone-based polar solvents such as β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, and ε-caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate, and ethyl cellosolve acetate; and phenolic solvents such as cresols.

[0191] Among them, as the organic solvent here, a nitrogen-containing polar solvent is preferably used from the viewpoint of solubility of the produced polyamic acid.

[0192] In addition, a mixed solvent containing a lactone-based polar solvent is preferably used from the viewpoint of film-forming properties, etc. In this case, the content of the lactone-based polar solvent is preferably 1 to 20% by mass, more preferably 5 to 15% by mass, relative to the entire organic solvent (100% by mass).

[0193] Among the organic solvents herein, it is preferred to use one or more selected from the group consisting of nitrogen-containing polar solvents and lactone-based polar solvents, and it is more preferred to use a mixed solvent of a nitrogen-containing polar solvent and a lactone-based polar solvent.

[0194] The amount of the organic solvent used is not particularly limited, but is preferably such that the content of the generated polyamic acid in the reaction solution after the reaction is 5 to 50% by mass.

[0195] The usage-amounts of tetracarboxylic dianhydride and diamine are not particularly limited, but 0.50 to 1.50 mol of diamine is preferably used, 0.60 to 1.30 mol is more preferably used, and 0.70 to 1.20 mol is particularly preferably used based on 1 mol of tetracarboxylic dianhydride.

[0196] The reaction (polymerization) temperature is usually -10 to 120° C., preferably 5 to 30° C. The reaction (polymerization) time varies depending on the composition of the raw materials used, but is usually 3 to 24 (hours).

[0197] The intrinsic viscosity of the polyamic acid solution obtained under such conditions is preferably in the range of 1,000 to 100,000 cP (centipoise) (1 to 100 Pa·s), and more preferably in the range of 5,000 to 70,000 cP (5 to 70 Pa·s).

[0198] The intrinsic viscosity of the polyamic acid solution can be measured at a temperature of 25° C. using an E-type rotational viscometer.

[0199] ···Polyimide

[0200] The polyimide that can be used in the present embodiment is not limited in structure or molecular weight as long as it is soluble in the organic solvent used for the varnish, and a known polyimide can be used.

[0201] The polyimide may have a condensable functional group such as a carboxyl group or a functional group that promotes a crosslinking reaction during firing in a side chain.

[0202] In order to make a polyimide soluble in an organic solvent used for a varnish, it is effective to use a monomer for introducing a flexible curved structure into the main chain.

[0203] Examples of the monomer include aliphatic diamines such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, and 4,4'-diaminodicyclohexylmethane; aromatic diamines such as 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, and 4,4'-diaminobenzanilide; polyoxyalkylene diamines such as polyoxyethylenediamine, polyoxypropylenediamine, and polyoxybutylenediamine; polysiloxane diamine; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, and 2,2-bis(4-hydroxyphenyl)propane dibenzoate-3,3',4,4'-tetracarboxylic dianhydride.

[0204] It is also effective to use a monomer having a functional group that improves solubility in the organic solvent. Examples of such a monomer having a functional group include fluorinated diamines such as 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2-trifluoromethyl-1,4-phenylenediamine.

[0205] Furthermore, in addition to the monomer having a functional group, the monomers exemplified in the description of the polyamic acid may be used in combination within a range not inhibiting solubility.

[0206] 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 and then dissolved in an organic solvent.

[0207] Examples of the polyimide that can be used in the present embodiment include aliphatic polyimide (wholly aliphatic polyimide) and aromatic polyimide. Among them, aromatic polyimide is preferred.

[0208] The aromatic polyimide may be one obtained by subjecting a polyamic acid having a structural unit represented by the following general formula (5) to a thermal or chemical ring-closure reaction, or one obtained by dissolving a polyimide having a structural unit represented by the following general formula (6) in a solvent.

[0209] In the formula, R Ar Represents an aryl group, R' Ar It represents an arylene group.

[0210] [Chemical formula 3]

[0211]

[0212] In the above formula, R ArAs long as it is a cyclic conjugated system with 4n+2 π electrons, it is not particularly limited and may be a monocyclic or polycyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a portion of the carbon atoms constituting the above aromatic hydrocarbon rings are replaced by heteroatoms, etc. Examples of heteroatoms in the aromatic heterocyclic ring include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. Specific examples of the aromatic heterocyclic ring include pyridine rings, thiophene rings, and the like. Among them, R Ar An aromatic hydrocarbon ring is preferred, benzene and naphthalene are more preferred, and benzene is particularly preferred.

[0213] In the above formula, R' Ar From the above R Ar The group obtained by removing two hydrogen atoms from the aromatic ring in Ar The group obtained by removing two hydrogen atoms from an aromatic hydrocarbon ring is preferred, the group obtained by removing two hydrogen atoms from benzene or naphthalene is more preferred, and the phenylene group obtained by removing two hydrogen atoms from benzene is particularly preferred.

[0214] R Ar The aromatic group, R' Ar The arylene groups in each may have a substituent.

[0215] ···Polyamide-imide

[0216] The polyamide-imide that can be used in the present embodiment is not limited in structure or molecular weight as long as it is soluble in an organic solvent used in the varnish, and a known polyamide-imide can be used.

[0217] The polyamideimide may have a condensable functional group such as a carboxyl group or a functional group that promotes a crosslinking reaction during calcination in a side chain.

[0218] The polyamideimide may be any polyamideimide obtained by reaction of any trimellitic anhydride and diisocyanate, or any polyamideimide obtained by imidizing a precursor polymer obtained by reaction of any reactive derivative of trimellitic anhydride and diamine without particular limitation.

[0219] Examples of the reactive derivatives of any of the trimellitic anhydride include trimellitic anhydride halides such as trimellitic anhydride chloride and trimellitic anhydride esters.

[0220] Examples of the above-mentioned optional diisocyanates include m-phenylene diisocyanate, p-phenylene diisocyanate, o-tolidine diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4'-oxybis(phenylisocyanate), 4,4'-diisocyanate diphenylmethane, bis[4-(4-isocyanatephenoxy)phenyl]sulfone, 2,2'-bis[4-(4-isocyanatephenoxy)phenyl]propane, 2,4-methane Phenyl diisocyanate, 2,6-toluene 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, etc.

[0221] As said arbitrary diamine, the diamine similar to the diamine mentioned as an example in the description of the said polyamic acid is mentioned.

[0222] ···Organic solvents

[0223] The organic solvent that can be used in the preparation of the varnish is not particularly limited as long as it can dissolve the polyamic acid and / or polyimide resin and does not dissolve the microparticles, and the same organic solvent as that used in the reaction of tetracarboxylic dianhydride and diamine can be cited. The organic solvent can be used alone or in combination of two or more.

[0224] 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.

[0225] In the [film formation of unfired composite film] described later, when the unfired composite film is formed into a two-layered state, the volume ratio of the polyamic acid or polyimide or polyamide-imide (A1) to the microparticles (B1) in the first varnish is preferably 19:81 to 45:55. If the volume ratio of the microparticles (B1) is 55 or more (when the whole is set to 100), the particles are uniformly dispersed, and if it is 81 or less, the particles are easily dispersed and do not agglomerate. Thus, pores can be uniformly formed on the substrate side of the polyimide resin formed film.

[0226] In addition, the volume ratio of the polyamic acid or polyimide or polyamide-imide (A2) to the microparticles (B2) in the second varnish is preferably set to 20:80 to 50:50. If the volume ratio of the microparticles (B2) is 50 or more (when the whole is set to 100), the particle monomers are easily dispersed uniformly, and if it is 80 or less, the particles will not agglomerate with each other, and cracks are not easily generated on the surface. As a result, it is easy to form a polyimide resin porous film with good mechanical properties such as stress and elongation at break.

[0227] Regarding the above-mentioned volume ratio, the second varnish is preferably a varnish having a particle content ratio lower than that of the above-mentioned first varnish. By satisfying the above-mentioned conditions, even if particles are highly filled into polyamic acid or polyimide or polyamide-imide, the strength and flexibility of the unfired composite film, polyimide resin-particle composite film, and polyimide resin porous film can be ensured. In addition, by providing a layer with a low particle content ratio, the reduction of manufacturing cost is achieved.

[0228] When preparing the varnish, in addition to the above-mentioned components, for the purpose of antistatic, imparting flame retardancy, low-temperature sintering, releasability, coating properties, etc., known components such as antistatic agents, flame retardants, chemical imidization agents, condensation agents, release agents, surface conditioning agents, etc. may also be added as needed.

[0229] [Film formation of unfired composite film]

[0230] The formation of an unfired composite film containing polyamic acid or polyimide or polyamide-imide and microparticles can be carried out, for example, by applying the above-mentioned varnish on a substrate and drying it under normal pressure or vacuum at 0 to 120° C. (preferably 0 to 100° C.), more preferably under normal pressure at 60 to 95° C. (further preferably 65 to 90° C.). The coating thickness is, for example, preferably 1 to 500 μm, more preferably 5 to 50 μm.

[0231] It should be noted that a release layer may be provided on the substrate as required. In addition, in the film formation of the unfired composite film, an immersion step, a drying step, and a pressurization step in a solvent containing water may be provided as optional steps before [firing of the unfired composite film] described later.

[0232] The release layer can be prepared by applying a release agent on a substrate and drying or baking. The release agent used herein can use known release agents such as alkyl phosphate ammonium salt release agents, fluorine-based release agents or silicone-based release agents without particular limitation. When the unfired composite film after drying is peeled off from the substrate, a slight amount of release agent will remain on the peeling surface of the unfired composite film. The residual release agent will affect the wettability and impurity mixing of the surface of the polyimide resin porous film, so it is preferably removed in advance.

[0233] Therefore, the unsintered composite film peeled from the substrate is preferably washed with an organic solvent, etc. Examples of the washing method include known methods such as immersing the unsintered composite film in a washing solution and then taking it out, and performing spray washing.

[0234] In order to dry the cleaned unfired composite film, for example, the cleaned unfired composite film is air-dried at room temperature or heated to an appropriate set temperature in a thermostatic bath. At this time, for example, a method of fixing the end of the unfired composite film to a SUS frame or the like to prevent deformation can also be adopted.

[0235] On the other hand, when the substrate is used directly without providing a release layer in forming the unfired composite film, the step of forming the release layer and the step of washing the unfired composite film can be omitted.

[0236] In addition, when the unfired composite film is formed in two layers, first, the above-mentioned first varnish is directly applied on a substrate such as a glass substrate, and dried under normal pressure or vacuum and 0 to 120°C (preferably 0 to 90°C), more preferably under normal pressure and 10 to 100°C (further preferably 10 to 90°C), thereby forming the first unfired composite film with a film thickness of 1 to 5 μm.

[0237] Next, the second varnish is applied on the first unfired composite film, and dried at 0 to 80°C (preferably 0 to 50°C), more preferably at normal pressure and 10 to 80°C (further preferably 10 to 30°C), to form a second unfired composite film having a film thickness of 5 to 50 μm, thereby forming a two-layered unfired composite film.

[0238] [Firing of unfired composite film]

[0239] After the above-mentioned [Film formation of unfired composite film], the unfired composite film is subjected to a heat treatment (fired) to form a composite film (polyimide resin-microparticle composite film) containing a polyimide resin and microparticles.

[0240] When the varnish contains a polyamic acid, it is preferred that imidization be completed in the [calcination of the uncalcined composite film] of this step.

[0241] The temperature of the heat treatment (calcination temperature) varies depending on the structure of the polyamic acid, polyimide or polyamideimide contained in the uncalcined composite film and the presence or absence of a condensation agent, but is preferably 120 to 400°C, more preferably 150 to 375°C.

[0242] When calcining, it is not necessary to clearly separate the operation from the drying in the previous process. For example, when calcining at 375°C, a method of heating from room temperature to 375°C in 3 hours and then keeping it at 375°C for 20 minutes can also be used; a step-by-step drying-thermal imidization method can be used, such as heating from room temperature to 375°C in steps of 50°C (keeping it at each step for 20 minutes), and finally keeping it at 375°C for 20 minutes. At this time, a method of fixing the end of the uncalcined composite film to a SUS frame or the like to prevent deformation can also be used.

[0243] 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.

[0244] The thickness of the polyimide resin-fine particle composite film can be obtained by measuring the thickness at a plurality of locations using a micrometer and averaging the measured thickness.

[0245] It should be noted that this step is an optional step and may not be performed when polyimide or polyamide-imide is used in the varnish.

[0246] [Removal of fine particles]

[0247] After the above-mentioned [calcination of the uncalcined composite membrane], the fine particles are removed from the polyimide-based resin-fine particle composite membrane, thereby producing a porous polyimide-based resin membrane.

[0248] For example, when silicon dioxide is used as the microparticles, the polyimide resin-microparticle composite film is brought into contact with a low concentration of hydrogen fluoride (HF) aqueous solution to dissolve and remove silicon dioxide to obtain a porous film. Alternatively, when the microparticles are resin microparticles, the resin microparticles are decomposed and removed by heating to a temperature that is higher than the thermal decomposition temperature of the resin microparticles and lower than the thermal decomposition temperature of the polyimide resin to obtain a porous film.

[0249] [Etching (opening of imide bonds)]

[0250] The etching step can be performed by a chemical etching method, a physical removal method, or a combination of these methods.

[0251] About chemical etching

[0252] As the chemical etching method, a conventionally known method can be used.

[0253] The chemical etching method is not particularly limited, and examples thereof include treatment with an etching solution such as an inorganic alkaline solution or an organic alkaline solution. Among them, treatment with an inorganic alkaline solution is preferred.

[0254] 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, sodium metasilicate, etc.; an ammonia solution; an etching solution mainly composed of alkali hydroxide, hydrazine, and 1,3-dimethyl-2-imidazolidinone, etc.

[0255] Examples of the organic alkali 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; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and alkaline etching solutions such as cyclic amines such as pyrrole and piperidine. The alkali concentration in the etching solution is, for example, 0.01 to 20% by mass.

[0256] The solvent of each of the above-mentioned etching solutions can be appropriately selected from pure water and alcohols. Alternatively, a solvent to which a suitable amount of a surfactant is added may be used.

[0257] About physical removal methods

[0258] As the physical removal method, for example, dry etching using plasma (oxygen, argon, etc.), corona discharge, or the like can be used.

[0259] The chemical etching method or physical removal method may be applied before or after the above-mentioned [removal of particles].

[0260] Among them, it is preferably applied after the above-mentioned [removal of fine particles] from the viewpoints of easier formation of interconnected pores inside the polyimide-based resin porous membrane and improved removability of foreign matter.

[0261] When chemical etching is performed in the etching step, a step of washing the porous polyimide resin membrane may be provided after this step in order to remove excess etching solution.

[0262] The cleaning after chemical etching may be water cleaning alone, or preferably a combination of acid cleaning and water cleaning.

[0263] In addition, after the etching step, in order to improve the wettability of the polyimide resin porous membrane surface to the organic solvent and remove residual organic matter, the polyimide resin porous membrane can be subjected to heat treatment (re-firing). The heating conditions are the same as those in the above-mentioned [firing of unfired composite membrane].

[0264] The polyimide resin porous membrane manufactured by, for example, the above-mentioned manufacturing method forms spherical pore chambers and connecting holes that connect adjacent spherical pore chambers to each other, preferably having the following connecting holes: the connecting holes opening on one external surface connect the interior of the porous membrane and open to the other (back side) external surface, thereby ensuring a flow path for the fluid to pass through the porous membrane.

[0265] As for the Gurley air permeability of the "porous membrane in which adjacent spherical pores are connected to each other", for example, from the perspective of maintaining the flow rate of the filtered object passing through the porous membrane at a relatively high level and removing foreign matter efficiently, it is preferably 30 seconds or more. 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 below the preferred upper limit of the above range, the degree of porosity (such as the presence ratio of connected pores) is sufficiently high, so it is easier to obtain the effect of removing foreign matter.

[0266] The Gurley air permeability of the porous film can be measured in accordance with JIS P 8117.

[0267] The "porous membrane in which adjacent spherical cells communicate with each other" preferably includes 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 10 to 130 nm.

[0268] The aperture of the communicating hole refers to the diameter of the communicating hole. It should be noted that, based on the above-mentioned manufacturing method, one communicating hole is usually formed by two adjacent particles, so, for example, if the direction in which the two holes constituting the communicating hole are adjacent is set as the length direction, the diameter includes the case where the diameter is taken in the direction perpendicular to the length direction.

[0269] When the above-mentioned etching (opening of imide bonds) step is not provided, the diameter of the communicating pores tends to be smaller.

[0270] The average pore diameter of the "porous membrane in which adjacent spherical cells communicate with each other" is preferably 100 to 2000 nm, more preferably 200 to 1000 nm, and even more preferably 300 to 900 nm.

[0271] The average pore size of the porous membrane is a value obtained by measuring the diameter of the interconnected pores of the porous membrane (e.g., a polyimide porous membrane) subjected to the above-mentioned chemical etching using a Perm-porometer (e.g., manufactured by Porous Materials) based on the bubble point method. For porous membranes (e.g., polyamide-imide porous membranes) not subjected to chemical etching, the average particle size of the microparticles used in the manufacture of the porous membrane is set as the average pore size.

[0272] As described above, the "porous membrane in which adjacent spherical cells are connected to each other" is preferably a porous membrane containing pores having an average pore size of several hundred nanometers. Therefore, the pores and / or connected pores in the porous membrane can also adsorb or capture minute substances, such as nanometers.

[0273] The diameter of the communicating pores tends to be such that as the pore size distribution of each pore that imparts porosity to the "porous membrane in which adjacent spherical cells communicate with each other" becomes wider, the diameter of the communicating pores formed by adjacent pores becomes smaller.

[0274] From the viewpoint of reducing the pore size of the interconnecting pores, the porosity of the "porous membrane in which adjacent spherical pores are interconnected" is preferably 50% by mass or more, more preferably 60 to 90% by mass, further preferably 60 to 80% by mass, and particularly preferably about 70% by mass. When the porosity is above the preferred lower limit of the above range, it is easier to obtain the effect of removing foreign matter. When it is below the preferred upper limit of the above range, the strength of the porous membrane is further improved.

[0275] The porosity of the porous film is determined by calculating the ratio of the mass of the fine particles to the total mass of the resin and the fine particles used in producing the porous film.

[0276] In addition, the "porous membrane in which adjacent spherical cells are connected to each other" preferably contains connected pores having an average pore size of 0.01 to 50 nm as determined by the BET method, more preferably 0.05 to 10 nm. The average pore size of the connected pores is more preferably 0.1 to 40 nm, further preferably 1 to 30 nm, and particularly preferably 1 to 20 nm.

[0277] By having interconnecting pores having an average pore diameter based on the BET method within the above range, high molecular weight entities (for example, molecules with a molecular weight of 30,000 or more in the molecular weight distribution) that may cause defects in the resist pattern can be effectively reduced in the resin used in the semiconductor manufacturing process.

[0278] The so-called BET method refers to the following method: by allowing adsorbed molecules (for example, nitrogen) to adsorb and desorb on a porous body to measure the adsorption isotherm, the measured data is analyzed based on the BET formula represented by the following formula (Be1). Based on this method, the specific surface area A and the total pore volume V can be calculated, and then based on the obtained specific surface area A and total pore volume V, the average pore diameter can be calculated by the formula [4V / A]. It should be noted that the specific surface area obtained by the BET method is preferably 15m 2 / g or more, more preferably 20m 2 / g and above and 200m 2 / g or less, more preferably 25m 2 / g or more and 100m 2 / g or less.

[0279] Specifically, first, the adsorption isotherm is obtained by adsorbing and desorbing the adsorbed molecules on the porous body. Then, based on the obtained adsorption isotherm, [P / {Va(P0-P)}] is calculated based on the following formula (B1), and a plot is made relative to the equilibrium relative pressure (P / P0). Then, the curve is regarded as a straight line, and the slope s (= [(C-1) / (Vm·C)]) and the intercept I (= [1 / (Vm·C)]) are calculated based on the least squares method. Then, based on the obtained slope s and intercept I, Vm and C are calculated based on formula (Be2-1) and formula (B2-2). Furthermore, based on Vm, the specific surface area A can be calculated based on formula (Be3). Furthermore, the adsorption data of the obtained adsorption isotherm are linearly interpolated to obtain the adsorption amount at the relative pressure set by calculating the relative pressure based on the pore volume. The total pore volume V can be calculated from the adsorption amount. The BET method is a measurement method in accordance with JIS R1626-1996 "Measurement method of specific surface area of ​​fine ceramic powder by gas adsorption BET method". There are no particular limitations on the measurement apparatus by the BET method, and examples thereof include Micromeritics (manufactured by Shimadzu Corporation).

[0280] [P / {V a (P 0 -P)}]

[0281] =[1 / (V m ·C)]+[(C-1) / (V m ·C)](P / P 0 )···(1)

[0282] V m =1 / (s+i)···(2-1)

[0283] C=(s / ⅰ)+1···(2-2)

[0284] A=(V m ·L·σ) / 22414···(3)

[0285] Va: adsorption amount

[0286] Vm: adsorption capacity of monolayer

[0287] P: The equilibrium pressure of adsorbed molecules

[0288] P0: saturated vapor pressure of adsorbed molecules

[0289] L: Avogadro constant

[0290] σ: adsorption cross-sectional area of ​​adsorbed molecules

[0291] In addition, the average pore size of the "porous membrane in which adjacent spherical pores are connected to each other" obtained by a porometer is preferably less than 100 nm, and more preferably less than 90 nm. The maximum value of the pore size distribution (%) obtained by the porometer is preferably more than 40%, more preferably more than 45%, and further preferably more than 50%. In addition, the maximum pore size (hereinafter referred to as pore size A) of the pore size distribution (%) is preferably less than 100 nm, and more preferably less than 90 nm. In addition, the ratio of pore size A obtained by the porometer to the maximum pore size in the pore size distribution range (maximum pore size / pore size A) is preferably less than 1.4, more preferably less than 1.3, and further preferably less than 1.2.

[0292] The “porous film in which adjacent spherical cells communicate with each other” is excellent in mechanical properties such as stress and elongation at break.

[0293] The stress of the “porous membrane in which adjacent spherical cells communicate with each other” included in the filter is, for example, preferably 10 MPa or more, more preferably 15 MPa or more, and further preferably 15 to 50 MPa.

[0294] The stress of the porous film was set to a value measured by preparing a sample having a size of 4 mm×30 mm and using a testing machine under measurement conditions of 5 mm / min.

[0295] In addition, the elongation at break of the "porous membrane in which adjacent spherical pores are connected to each other" is preferably 10% GL or more, more preferably 15% GL or more. The upper limit of the elongation at break is 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 membrane is reduced, the elongation at break tends to increase.

[0296] The elongation at break of the porous membrane is set to a value measured by preparing a sample having a size of 4 mm×30 mm and using a testing machine under measurement conditions of 5 mm / min.

[0297] The thermal decomposition temperature of the "porous film in which adjacent spherical cells communicate with each other" is preferably 200°C or higher, more preferably 320°C or higher, and even more preferably 350°C or higher.

[0298] The thermal decomposition temperature of the porous film can be measured by increasing the temperature to 1000° C. at a temperature increase rate of 10° C. / min in an air atmosphere.

[0299] The filter in this embodiment is not limited to having Figure 1The porous membrane filter having such a connecting hole 5 (which is formed by connecting the adjacent spherical pores 1a and spherical pores 1b) as shown may also be provided with a porous membrane having connecting holes 5 and pores or connecting holes of other forms. As pores of other forms (hereinafter referred to as "other pores"), pores of different shapes or pore diameters can be cited, for example, elliptical pores, polyhedral pores, spherical pores of different pore diameters, etc. As the above-mentioned "connecting holes of other forms", for example, connecting holes formed by connecting a spherical pore and other pores can be cited.

[0300] The shapes and diameters of other cells may be appropriately determined according to the type of impurities to be removed. The communicating holes formed by the spherical cells communicating with other cells can be formed by selecting the material of the particles, controlling the shape of the particles, and the like.

[0301] A filter including a porous membrane having communicating holes in which adjacent spherical cells communicate with each other and cells or communicating holes of other shapes can more efficiently remove various foreign substances from a filter object.

[0302] In addition, the filter in this embodiment can be replaced with a filter element or the like that has been installed to remove particulate impurities in the supply pipeline or POU (point of use) of various chemical solutions in the semiconductor manufacturing process, or can also be used in combination with the filter element. Therefore, various foreign matters can be efficiently removed from the filtered object (chemical solution for photolithography) using the same device and operation as before, and a highly pure resist composition purified product can be prepared.

[0303] 《Filtration of resist composition》

[0304] The filtration of the resist composition using a filter having a porous structure in which adjacent spherical pores are connected to each other can be performed in a state without a pressure difference (that is, the resist composition can be passed through the filter only by gravity), or in a state where a pressure difference is set. Among them, the latter is preferred, and the operation of passing the resist composition through the filter using a pressure difference is preferably performed.

[0305] The “state in which a pressure difference is provided” means that there is a pressure difference between one side and the other side of the porous polyimide resin membrane provided in the filter.

[0306] For example, there can be mentioned: pressurization (positive pressure) in which pressure is applied to one side of the polyimide resin porous membrane (resist composition supply side); decompression (negative pressure) in which one side of the polyimide resin porous membrane (filtrate side) becomes negative pressure, etc. In the filtration step of this embodiment, the former pressurization is preferred.

[0307] Pressurization is to apply pressure to the supply liquid side of the porous polyimide resin membrane where the resist composition (hereinafter sometimes referred to as “supply liquid”) exists before passing through the porous polyimide resin membrane.

[0308] For example, it is preferable to utilize the flow pressure generated during the circulation or flow of the supply liquid, or utilize the positive pressure of the gas, thereby applying pressure to the supply liquid side.

[0309] For example, the flow hydraulic pressure can be generated by the positive flow hydraulic pressure addition method of a pump (liquid delivery pump, circulation pump, etc.). Examples of the pump include rotary pumps, diaphragm pumps, metering pumps, chemical pumps, piston pumps, bellows pumps, gear pumps, vacuum pumps, air pumps, liquid pumps, etc.

[0310] When the supply liquid is circulated or sent by a pump, the pump is usually arranged between the supply liquid tank (or circulation tank) and the polyimide-based resin porous membrane.

[0311] The flow pressure may be, for example, the pressure applied to the polyimide resin porous membrane by the supply liquid when the supply liquid passes through the polyimide resin porous membrane only by gravity, but is preferably the pressure applied by the above-mentioned active flow pressure adding method.

[0312] As the gas used for pressurization, a gas that is inactive or non-reactive with respect to the supply liquid is preferable, and specific examples thereof include nitrogen gas, and rare gases such as helium gas and argon gas.

[0313] As a method of applying pressure to the supply liquid side, it is preferable to utilize positive pressure of gas. In this case, the filtrate side passing through the polyimide resin porous membrane may be at atmospheric pressure without reducing the pressure.

[0314] In addition, pressurization may be pressurization using both fluid pressure and positive pressure of gas. In addition, as for the pressure difference, pressurization and pressure reduction may be combined, for example, both fluid pressure and pressure reduction may be used, both positive pressure and pressure reduction of gas may be used, or both fluid pressure and positive pressure of gas may be used and pressure reduction may be used. When combining methods for setting the pressure difference, a combination of fluid pressure and positive pressure of gas, or a combination of fluid pressure and pressure reduction is preferred from the perspective of simplification of manufacturing, etc.

[0315] In the present embodiment, since a porous polyimide resin membrane is used, even if the method of providing the pressure difference is a method such as positive pressure based on gas, the foreign matter removal performance is excellent.

[0316] The reduced pressure is to reduce the pressure on the filtrate side passing through the polyimide-based resin porous membrane, and may be reduced pressure by, for example, a pump, and is preferably reduced pressure to a vacuum.

[0317] When the operation of passing the resist composition from the filter is performed under a state where a pressure difference is provided, the pressure difference is appropriately set in consideration of the film thickness, porosity or average pore size of the polyimide-based resin porous membrane used, or the desired degree of purification, flow rate, flow rate, or concentration or viscosity of the supply liquid. For example, the pressure difference during the so-called cross-flow mode (flowing through the supply liquid in parallel with respect to the polyimide-based resin porous membrane) is, for example, preferably less than 0.3MPa. The pressure difference during the so-called dead end mode (cross-flowing into the supply liquid relative to the polyimide-based resin porous membrane) is, for example, preferably less than 1MPa, more preferably less than 0.3MPa. The lower limit of each pressure difference is preferably more than 0.01MPa, more preferably more than 0.05MPa.

[0318] In the step (i), the operation of passing the resist composition through the filter having the polyimide resin porous membrane can be performed while maintaining a high flow rate of the resist composition (supply liquid).

[0319] The flow rate in this case is not particularly limited, 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, further preferably 5 mL / min or more, and particularly preferably 10 mL / min or more. The upper limit of the flow rate is not particularly limited, for example, 50 mL / min or less.

[0320] In the present embodiment, since the filter including the above-mentioned polyimide-based resin porous membrane is used, filtration can be performed while maintaining a high flow rate as described above, thereby improving the removal rate of foreign matter contained in the resist composition.

[0321] In the step (i), the operation of passing the resist composition through the filter is preferably performed while setting the temperature of the resist composition to 0 to 30°C, more preferably 5 to 25°C.

[0322] In step (i), the resist composition may be passed through a filter having a porous polyimide resin membrane multiple times (perform multiple cycle filtrations), or may be passed through multiple filters including at least a filter having a porous polyimide resin membrane.

[0323] In addition, before the supply liquid is passed through the polyimide resin porous membrane, in order to clean the polyimide resin porous membrane, improve the wettability to the supply liquid, or adjust the surface energy of the polyimide resin porous membrane and the supply liquid, a solution of an alcohol such as methanol, ethanol, isopropanol, or a ketone such as acetone, methyl ethyl ketone, water, a solvent contained in the supply liquid, or a mixture thereof can be brought into contact with the polyimide resin porous membrane to pass the liquid. In order to bring the above-mentioned solution into contact with the polyimide resin porous membrane, the polyimide resin porous membrane can be impregnated in the above-mentioned solution, or the polyimide resin porous membrane can be immersed in the above-mentioned solution. By bringing the above-mentioned solution into contact with the polyimide resin porous membrane, the solution can, for example, penetrate into the pores inside the polyimide resin porous membrane. The contact between the solution and the porous polyimide resin membrane may be performed in the state where the pressure difference is provided. In particular, when the solution is allowed to penetrate into the pores inside the porous polyimide resin membrane, it is preferably performed under pressure.

[0324] <Other Process>

[0325] The manufacturing method involved in the present embodiment may further include other processes in addition to the above-mentioned step (i). As other processes, for example, a process of filtering using other filters other than the filter having a polyimide resin porous membrane can be cited. The filter other than the above-mentioned filter having a polyimide resin porous membrane is not particularly limited, for example, a filter having a porous membrane of a thermoplastic resin such as a nylon membrane, a polyethylene membrane, a polypropylene membrane, a polytetrafluoroethylene (PTFE) membrane, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) membrane, and a membrane obtained by modifying them can be cited. Among them, from the aspect of excellent removal performance of foreign matter, as other filters, it is preferred to use a filter having a porous membrane containing a polyethylene resin.

[0326] 《Process (ii)》

[0327] The manufacturing method according to the present embodiment preferably includes, in addition to the above step (i), a step (ii) of filtering using a filter having a porous membrane containing a polyethylene resin. The porous membrane containing a polyethylene resin (hereinafter also referred to as a "polyethylene resin porous membrane") may be formed only of a polyethylene resin, or may contain a polyethylene resin and other resins, but is preferably formed only of a polyethylene resin.

[0328] The polyethylene resin porous film is not particularly limited, and a known film can be used. The polyethylene resin porous film is preferably a porous film of ultrahigh molecular weight polyethylene (UPE) from the viewpoint of excellent impact resistance, abrasion resistance, and chemical resistance.

[0329] The average pore size of the polyethylene resin porous film is not particularly limited, but is preferably 0.1 to 100 nm, more preferably 0.3 to 50 nm, and even more preferably 0.5 to 10 nm from the viewpoint of removing fine foreign matter.

[0330] Examples of the filter including the polyethylene resin porous membrane include a filter including the polyethylene resin porous membrane in an outer container formed of a thermoplastic resin (polyethylene, polypropylene, PFA, polyethersulfone (PES), polyimide, polyamide-imide, etc.).

[0331] The step (ii) is preferably performed after the step (i). In this case, the average pore size of the polyethylene resin porous membrane is preferably smaller than the average pore size of the continuous pores of the polyimide-based porous membrane.

[0332] In the manufacturing method of the present embodiment, step (ii) can be repeated after the above step (i). In this case, the resist composition (supply liquid) is continuously circulated while passing through a filter having a polyimide resin porous membrane and a filter having a polyethylene resin porous membrane. In the case of the above-mentioned circulation type filtration, in the circulation path, the two filters are preferably configured in the following manner: the resist composition passes through the filter having a polyimide resin porous membrane and then passes through the filter having a polyethylene resin porous membrane.

[0333] When performing step (ii), as described in the above step (i), before allowing the supply liquid to pass through the polyethylene resin porous membrane, in order to clean the polyethylene resin porous membrane, improve the wettability to the supply liquid, or adjust the surface energy between the polyethylene resin porous membrane and the supply liquid, a solution of alcohol such as methanol, ethanol, isopropanol, or ketone such as acetone, methyl ethyl ketone, water, a solvent contained in the supply liquid, or a mixture thereof can be brought into contact with the polyethylene resin porous membrane to allow the liquid to pass.

[0334] <Resist composition>

[0335] The resist composition to be filtered contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S). The content of the organic solvent component (S) in the resist composition is 97% by mass or more.

[0336] When a resist film is formed using the resist composition and the resist film is selectively exposed, an acid is generated at the exposed portion of the resist film. Due to the action of the acid, the solubility of the component (A) in the developer changes. On the other hand, at the unexposed portion of the resist film, the solubility of the component (A) in the developer does not change. Therefore, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0337] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition.

[0338] The resist composition may be a positive resist composition or a negative resist composition.

[0339] The resist composition can be used in an alkali development process using an alkali developer in the development process during resist pattern formation, or in a solvent development process using a developer containing an organic solvent (organic developer).

[0340] That is, the resist composition is a "positive resist composition for alkali developing process" that forms a positive resist pattern in an alkali developing process, and is a "negative resist composition for solvent developing process" that forms a negative resist pattern in a solvent developing process.

[0341] The resist composition has an acid generating ability to generate an acid upon exposure. The component (A) may generate an acid upon exposure, or an additive component separately blended with the component (A) may generate an acid upon exposure.

[0342] Specifically, with respect to the resist composition, (1) it may be a resist composition containing an acid generator component (B) (hereinafter referred to as "component (B)") that generates an acid upon exposure; (2) it may be a component (A) that generates an acid upon exposure; and (3) it may be a resist composition that contains component (B) and a component that generates an acid upon exposure.

[0343] That is, in the case of (2) or (3) above, component (A) becomes a "base component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid". In the case where component (A) is a base component that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, component (A1) described later is preferably a polymer compound that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid. As such a polymer compound, a copolymer having a structural unit that generates acid upon exposure can be used. As the structural unit that generates acid upon exposure, for example, known structural units can be mentioned.

[0344] The resist composition is particularly preferably the case of (1) above.

[0345] The resist composition may also contain an alkali component (hereinafter also referred to as “component (D)”) that traps the acid generated by exposure (that is, controls the diffusion of the acid).

[0346] The onium salt contained in the resist composition as the filtering object may be contained in the component (B), the component (D), or the component (A). When the onium salt is contained in the component (A), the component (A) is a component that generates an acid by exposure.

[0347] 《About ingredient (A)》

[0348] In the resist composition, the component (A) is a base component whose solubility in a developer changes due to the action of an acid.

[0349] In the present invention, "base component" refers to an organic compound having film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and a resist pattern at the nanometer level can be easily formed.

[0350] Organic compounds used as base material components are roughly divided into non-polymers and polymers.

[0351] As non-polymers, substances with a molecular weight of 500 or more and less than 4000 are generally used. Hereinafter, when referred to as a "low molecular compound", a non-polymer with a molecular weight of 500 or more and less than 4000 is indicated. As polymers, substances with a molecular weight of 1000 or more are generally used. Hereinafter, when referred to as a "resin", "high molecular compound" or "polymer", a polymer with a molecular weight of 1000 or more is indicated. As the molecular weight of the polymer, the mass average molecular weight converted to polystyrene based on GPC (gel permeation chromatography) is used.

[0352] In the case where the resist composition is a "negative resist composition for alkali development process" that forms a negative resist pattern in an alkali development process, or a "positive resist composition for solvent development process" that forms a positive resist pattern in a solvent development process, it is preferred to use a base component (A-2) (hereinafter referred to as "component (A-2)") that is soluble in an alkali developer as component (A), and further mix a crosslinking agent component. For example, when an acid is generated from component (B) by exposure, the acid acts to cause crosslinking between component (A-2) and the crosslinking agent component, resulting in a decrease in solubility in an alkali developer (increase in solubility in an organic developer). Therefore, in the formation of the resist pattern, if the resist film obtained by coating the resist composition on the support is selectively exposed, the exposed portion of the resist will be converted into having poor solubility in the alkaline developer (soluble in the organic developer), while the unexposed portion of the resist will remain soluble in the alkaline developer (poorly soluble in the organic developer) without change, so a negative resist pattern is formed by developing with the alkaline developer. In addition, at this time, a positive resist pattern is formed by developing with the organic developer.

[0353] As a preferred example of the component (A-2), a resin soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is used.

[0354] As the alkali-soluble resin, the following resins are preferred from the viewpoint of being able to form a good resist pattern with little swelling: for example, a resin having a structural unit derived from at least one selected from α-(hydroxyalkyl)acrylic acid or an alkyl ester of α-(hydroxyalkyl)acrylic acid (preferably an alkyl ester having 1 to 5 carbon atoms), disclosed in Japanese Patent Application Laid-Open No. 2000-206694; an acrylic resin or a polycycloolefin resin having a sulfonamide group and a hydrogen atom bonded to a carbon atom at the α-position which may be substituted with a substituent, disclosed in U.S. Patent Application Laid-Open No. 6949325; an acrylic resin containing a fluoroalcohol and a hydrogen atom bonded to a carbon atom at the α-position which may be substituted with a substituent, disclosed in U.S. Patent Application Laid-Open No. 2005-336452 and Japanese Patent Application Laid-Open No. 2006-317803; a polycycloolefin resin having a fluoroalcohol, disclosed in Japanese Patent Application Laid-Open No. 2006-259582; and the like.

[0355] It should be noted that the above-mentioned α-(hydroxyalkyl) acrylic acid refers to one or both of acrylic acid in which the hydrogen atom bonded to the α-carbon atom to which the carboxyl group is bonded has a hydrogen atom bonded to it, and α-hydroxyalkyl acrylic acid in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the α-carbon atom in which the hydrogen atom bonded to the α-carbon atom is substituted with a substituent.

[0356] As the crosslinking agent component, for example, from the aspect of easily forming a good resist pattern with little swelling, it is preferred to use an amino crosslinking agent such as glycoluril having a hydroxymethyl group or an alkoxymethyl group, or a melamine crosslinking agent, etc. The amount of the crosslinking agent component is preferably 1 to 50 parts by mass relative to 100 parts by mass of the alkali-soluble resin.

[0357] In the case where the resist composition is a "positive resist composition for alkali development process" that forms a positive resist pattern in an alkali development process, or a "negative resist composition for solvent development process" that forms a negative resist pattern in a solvent development process, as component (A), it is preferred to use a base component (A-1) (hereinafter referred to as "component (A-1)") whose polarity increases due to the action of an acid. By using component (A-1), the polarity of the base component changes before and after exposure, and therefore, good development contrast can be obtained not only in an alkali development process but also in a solvent development process.

[0358] In the case of an alkali development process, the component (A-1) is poorly soluble in an alkali developer before exposure. For example, when an acid is generated by the component (B) by exposure, the polarity increases due to the action of the acid, and the solubility in the alkali developer increases. Therefore, in the formation of a resist pattern, if a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion of the resist film changes from poorly soluble to soluble in an alkali developer, while the unexposed portion of the resist film remains poorly soluble in alkali without changing, and thus a positive resist pattern is formed by performing alkali development.

[0359] On the other hand, when a solvent development process is applied, the solubility of the component (A-1) in an organic developer is high before exposure. When the component (B) generates an acid by exposure, the polarity becomes high due to the action of the acid, and the solubility in the organic developer decreases. Therefore, in the formation of a resist pattern, if the resist film obtained by coating the resist composition on a support is selectively exposed, the exposed part of the resist film changes from soluble to poorly soluble in an organic developer, while the unexposed part of the resist film remains soluble and unchanged. Therefore, by developing with an organic developer, a contrast can be generated between the exposed part and the unexposed part, and a negative resist pattern can be formed.

[0360] In the resist composition, the component (A) may be used alone or in combination of two or more.

[0361] In the resist composition, component (A) is preferably the above-mentioned component (A-1). That is, the resist composition is preferably a "positive resist composition for alkali development process" that forms a positive resist pattern in an alkali development process, or a "negative resist composition for solvent development process" that forms a negative resist pattern in a solvent development process. Component (A) may be at least one of a polymer compound and a low molecular weight compound.

[0362] When the component (A) is the component (A-1), it is preferred that the component (A-1) contains a resin component (A1) (hereinafter also referred to as “component (A1)”).

[0363] About ingredient (A1)

[0364] The component (A1) is a resin component, and preferably contains a polymer compound having a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of an acid.

[0365] The component (A1) preferably has a structural unit (a10) containing a hydroxystyrene skeleton in addition to the structural unit (a1).

[0366] In addition, the component (A1) may have, in addition to the structural unit (a1), a cyclic group containing a lactone, a -SO 2 -a structural unit (a2) containing a cyclic group or a cyclic group containing a carbonate; a structural unit (a3) ​​containing an aliphatic hydrocarbon group containing a polar group (wherein, the structural unit belonging to the structural unit (a1) or the structural unit (a2) is not included); or a structural unit (a6) that generates an acid by exposure.

[0367] The component (A1) may further have a structural unit other than the structural unit (a1), the structural unit (a2), the structural unit (a3), the structural unit (a10), and the structural unit (a6).

[0368] [Structural unit (a1)]

[0369] The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases under the action of an acid.

[0370] The "acid-decomposable group" is an acid-decomposable group such that at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.

[0371] Examples of the acid-decomposable group whose polarity increases under the action of an acid include a group that decomposes under the action of an acid to generate a polar group.

[0372] Examples of the polar group include a carboxyl group, a hydroxyl group, an amino group, a sulfone group (-SO3 H) etc. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "polar group containing OH") is preferred, a carboxyl group or a hydroxyl group is more preferred, and a carboxyl group is particularly preferred.

[0373] More specifically, the acid-decomposable group includes a group obtained by protecting the above-mentioned polar group with an acid-dissociable group (for example, a group obtained by protecting the hydrogen atom of a polar group containing OH with an acid-dissociable group).

[0374] Here, "acid-dissociable group" refers to the following: (i) an acid-dissociable group in which the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved under the action of an acid, or (ii) a group in which a portion of the bonds are cleaved under the action of an acid and then a decarboxylation reaction further occurs, thereby cleaving the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group.

[0375] The acid dissociative 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 dissociative group. Thus, when the acid dissociative group dissociates under the action of an acid, a polar group having a higher polarity than the acid dissociative group is generated, thereby increasing the polarity. As a result, the polarity of the component (A1) as a whole increases. Due to the increase in polarity, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0376] Examples of the acid-dissociable group include groups that have been proposed as acid-dissociable groups of base resins for chemically amplified resist compositions.

[0377] Specific examples of groups proposed as the acid-dissociable group of the base resin for the chemically amplified resist composition include the "acetal acid-dissociable group", "tertiary alkyl ester acid-dissociable group" and "tertiary alkyloxycarbonyl acid-dissociable group" described below.

[0378] Acetal type acid dissociative group:

[0379] Examples of the acid-dissociable group for protecting the carboxyl group or hydroxyl group in the polar group include an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0380] [Chemical formula 4]

[0381]

[0382] [where Ra' 1 , Ra' 2is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Can be with Ra' 1 , Ra' 2 Any of them are bonded to form a ring.]

[0383] In formula (a1-r-1), Ra' is preferred 1 and Ra' 2 At least one of them is a hydrogen atom, and more preferably both of them are hydrogen atoms.

[0384] Ra' 1 or Ra' 2 When the alkyl group is an alkyl group, examples of the alkyl group include the same groups as those exemplified as the substituents that can be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate, and preferably an alkyl group having 1 to 5 carbon atoms. Specifically, preferably, a linear or branched alkyl group can be mentioned. More specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. can be mentioned, and methyl or ethyl is more preferred, and methyl is particularly preferred.

[0385] In formula (a1-r-1), as Ra' 3 The hydrocarbon group includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0386] The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. are mentioned. Among these, methyl, ethyl, or n-butyl is preferred, and methyl or ethyl is more preferred.

[0387] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples thereof include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl, and isopropyl is preferred.

[0388] Ra' 3 In the case of a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0389] The aliphatic hydrocarbon group as the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a group having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0390] The aliphatic hydrocarbon group as the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a group having 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0391] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0392] The aromatic ring is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons, and can be a monocyclic or polycyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. As the aromatic ring, specifically, there can be mentioned: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings obtained by replacing a part of the carbon atoms constituting the above aromatic hydrocarbon rings with heteroatoms, etc. As heteroatoms in the aromatic heterocyclic ring, there can be mentioned oxygen atoms, sulfur atoms, nitrogen atoms, etc. As aromatic heterocyclic rings, specifically, there can be mentioned pyridine rings, thiophene rings, etc.

[0393] As Ra' 3 Specifically, the aromatic hydrocarbon group in the above-mentioned group includes: a group obtained by removing one hydrogen atom from the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group obtained by replacing one hydrogen atom of the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (e.g., arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group bonded to the above-mentioned aromatic hydrocarbon ring or aromatic heterocyclic ring preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0394] Ra' 3 The cyclic hydrocarbon group in may have a substituent. As the substituent, for example, -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter these substituents are collectively referred to as "Ra 05".)wait.

[0395] Here, R P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2 A part or all of the hydrogen atoms in the chain saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group and aromatic hydrocarbon group may be substituted by fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above substituents, or may have one or more of the above substituents.

[0396] Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and decyl groups.

[0397] Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl and adamantyl.

[0398] Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0399] Ra' 3 With Ra' 1 , Ra' 2 When any of them are bonded to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include tetrahydropyranyl and tetrahydrofuranyl.

[0400] Tertiary alkyl ester type acid dissociative group:

[0401] Examples of the acid-dissociable group for protecting the carboxyl group in the polar group include acid-dissociable groups represented by the following general formula (a1-r-2).

[0402] In addition, among the acid-dissociable groups represented by the following formula (a1-r-2), the group composed of an alkyl group may be referred to as a "tertiary alkyl ester type acid-dissociable group" for convenience.

[0403] [Chemical formula 5]

[0404]

[0405] [where Ra' 4 ~Ra' 6 Each is a hydrocarbon group, and Ra' 5 , Ra' 6 They may be bonded to each other to form a ring.]

[0406] As Ra' 4 The hydrocarbon group includes a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0407] Ra' 4 The linear or branched alkyl group and cyclic hydrocarbon group (aliphatic hydrocarbon group as a monocyclic group, aliphatic hydrocarbon group as a polycyclic group, aromatic hydrocarbon group) in the formula (R) include the following: 3 Same group.

[0408] Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms.

[0409] As Ra' 5 , Ra' 6 The hydrocarbon group may be the same as the above Ra' 3 Same group.

[0410] Ra' 5 With Ra' 6 When they are bonded to each other to form a ring, preferably, a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), or a group represented by the following general formula (a1-r2-3) is mentioned.

[0411] On the other hand, Ra' 4 ~Ra' 6 In the case of being independent hydrocarbon groups without being bonded to each other, preferably, a group represented by the following general formula (a1-r2-4) is mentioned.

[0412] [Chemical formula 6]

[0413]

[0414] [In formula (a1-r2-1), Ra' 10represents an alkyl group having 1 to 10 carbon atoms, or a group represented by the following general formula (a1-r2-r1). 11 Indicates that Ra' 10 The carbon atoms to which they are bonded together form an aliphatic cyclic group. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in the cyclic hydrocarbon group may be substituted. 01 ~Ra 03 Each independently represents a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. 01 ~Ra 03 Two or more of them are bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 04 is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 Each independently represents a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * represents a connecting bond (the same applies hereinafter).]

[0415] [Chemical formula 7]

[0416]

[0417] [In the formula, Ya 0 is a quaternary carbon atom. 031 , Ra 032 and Ra 033 Each is independently a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 At least one of them is a hydrocarbon group having at least one polar group.]

[0418] In the above formula (a1-r2-1), Ra' 10 The alkyl group having 1 to 10 carbon atoms is preferably Ra' in the formula (a1-r-1). 3 The group is a straight-chain or branched alkyl group. 10 An alkyl group having 1 to 5 carbon atoms is preferred.

[0419] In the above formula (a1-r2-r1), Ya 0is a quaternary carbon atom. 0 The number of adjacent carbon atoms bonded is 4.

[0420] In the above formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 Each is independently a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 The hydrocarbon groups in the alkyl groups are each independently a linear or branched alkyl group, a chain or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0421] Ra 031 , Ra 032 and Ra 033 The number of carbon atoms of the linear alkyl group in is preferably 1 to 5, more preferably 1 to 4, and further preferably 1 or 2. Specifically, methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. are mentioned. Among these, methyl, ethyl or n-butyl is preferred, and methyl or ethyl is more preferred.

[0422] Ra 031 , Ra 032 and Ra 033 The number of carbon atoms of the branched alkyl group in is preferably 3 to 10, more preferably 3 to 5. Specific examples thereof include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl, and isopropyl is preferred.

[0423] Ra 031 , Ra 032 and Ra 033 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms.

[0424] Ra 031 , Ra 032 and Ra 033 The cyclic hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0425] The aliphatic hydrocarbon group as a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0426] The aliphatic hydrocarbon group as the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0427] Ra 031 , Ra 032 and Ra 033 The aromatic hydrocarbon group in is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be a monocyclic or polycyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. As the aromatic ring, specifically, there can be mentioned: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings obtained by replacing a part of the carbon atoms constituting the above aromatic hydrocarbon rings with heteroatoms, etc. As heteroatoms in the aromatic heterocyclic ring, there can be mentioned oxygen atoms, sulfur atoms, nitrogen atoms, etc. As the aromatic heterocyclic ring, specifically, there can be mentioned pyridine rings, thiophene rings, etc. Specifically, the aromatic hydrocarbon group includes: a group obtained by removing one hydrogen atom from the above aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group obtained by replacing one hydrogen atom of the above aromatic hydrocarbon ring or aromatic heterocyclic ring with an alkylene group (e.g., arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms of the alkylene group bonded to the above aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0428] The above Ra 031 , Ra 032 and Ra 033 When the hydrocarbon group represented by is substituted, examples of the substituent include a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), and an alkyloxycarbonyl group.

[0429] Among the above, Ra 031 , Ra 032 and Ra 033 The hydrocarbon group which may have a substituent is preferably a linear or branched alkyl group which may have a substituent, and more preferably a linear alkyl group.

[0430] Among them, Ra 031 , Ra 032 and Ra 033 At least one of them is a hydrocarbon group having at least a polar group.

[0431] The so-called "hydrocarbon group having a polar group" is a hydrocarbon group in which the methylene group (-CH 2-) or a group in which at least one hydrogen atom constituting a hydrocarbon group is substituted with a polar group.

[0432] As the "hydrocarbon group having a polar group", a functional group represented by the following general formula (a1-p1) is preferred.

[0433] [Chemical formula 8]

[0434]

[0435] [where Ra 07 Ra represents a divalent hydrocarbon group having 2 to 12 carbon atoms. 08 Represents a divalent linking group containing a heteroatom. 06 It represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. p0 is an integer from 1 to 6.]

[0436] In the above formula (a1-p1), Ra 07 Ra represents a divalent hydrocarbon group having 2 to 12 carbon atoms. 07 The number of carbon atoms is 2 to 12, preferably 2 to 8, more preferably 2 to 6, further preferably 2 to 4, and particularly preferably 2.

[0437] Ra 07 The hydrocarbon group in is preferably a chain or cyclic aliphatic hydrocarbon group, more preferably a chain hydrocarbon group.

[0438] As Ra 07 For example, there can be mentioned straight-chain alkane diyl groups such as ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; propane-1,2-diyl, 1-methylbutane-1,3-diyl, 2-methylbutane-1, branched alkane diyl groups such as 1,3-propane-1,3-diyl, pentane-1,4-diyl and 2-methylbutane-1,4-diyl; cycloalkane diyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl and cyclooctane-1,5-diyl; polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl and adamantane-2,6-diyl.

[0439] Among the above, an alkanediyl group is preferred, and a linear alkanediyl group is more preferred.

[0440] In the above formula (a1-p1), Ra 08It represents a divalent linking group containing a heteroatom.

[0441] As Ra 08 For example, -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group), -S-, -S(=O) 2 -、-S(=O) 2 -O- etc.

[0442] Among these, -O-, -C(=O)-O-, -C(=O)-, and -OC(=O)-O- are particularly preferred, and -O- and -C(=O)- are more preferred, from the viewpoint of solubility in a developer.

[0443] In the above formula (a1-p1), Ra 06 Ra represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. 06 The carbon number of the moiety is 1 to 12, and from the viewpoint of solubility in a developer, the moiety is preferably 1 to 8, more preferably 1 to 5, further preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1.

[0444] Ra 06 The hydrocarbon group in may be a chain hydrocarbon group or a cyclic hydrocarbon group, or a combination of a chain hydrocarbon group and a cyclic hydrocarbon group.

[0445] Examples of the chain hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, 2-ethylhexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl.

[0446] The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group.

[0447] The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, cycloheptyl, cyclodecyl and other cycloalkyl groups. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkane-1-yl, norbornyl, methylnorbornyl, isobornyl and the like.

[0448] Examples of the aromatic hydrocarbon group include phenyl, naphthyl, anthracenyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumyl, mesityl, biphenylyl, phenanthryl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl.

[0449] As Ra 06 In view of solubility in a developer, a chain hydrocarbon group is preferred, an alkyl group is more preferred, and a straight-chain alkyl group is further preferred.

[0450] In the above formula (a1-p1), n p0 It is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and further preferably 1.

[0451] Specific examples of the hydrocarbon group having at least a polar group are shown below.

[0452] In the following formula, * is the quaternary carbon atom (Ya 0 ) bonding connection key.

[0453] [Chemical formula 9]

[0454]

[0455] In the above formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 The number of hydrocarbon groups having at least a polar group is 1 or more, and may be appropriately determined in consideration of the solubility in a developer during resist pattern formation. For example, Ra 031 , Ra 032 and Ra 033 It is preferred that one or two of them be a hydrocarbon group having at least a polar group, and it is particularly preferred that one of them be a hydrocarbon group.

[0456] The hydrocarbon group having at least a polar group may have a substituent other than the polar group. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.) and a halogenated alkyl group having 1 to 5 carbon atoms.

[0457] In formula (a1-r2-1), Ra' 11 (With Ra' 10 The aliphatic cyclic group formed by the carbon atoms bonded thereto is preferably Ra' in formula (a1-r-1): 3 The group mentioned above is an aliphatic hydrocarbon group (a monocyclic group or a polycyclic group).

[0458] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa and Ya together includes Ra' in the above formula (a1-r-1): 3A group obtained by removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group).

[0459] The cyclic hydrocarbon group formed by Xa and Ya together may have a substituent. Examples of the substituent include the above-mentioned Ra' 3 The cyclic hydrocarbon group in may have a substituent group similar to the group.

[0460] In formula (a1-r2-2), as Ra 01 ~Ra 03 The monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the group includes, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl and the like.

[0461] As Ra 01 ~Ra 03 The monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms includes, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl and adamantyl; and the like.

[0462] However, from the viewpoint of the ease of synthesis of the monomer compound from which the structural unit (a1) is derived, Ra 01 ~Ra 03 A hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, among which a hydrogen atom, a methyl group, and an ethyl group are more preferred, and a hydrogen atom is particularly preferred.

[0463] As the above Ra 01 ~Ra 03 The substituents possessed by the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula (R) include, for example, the substituents having the same meaning as Ra as above. 05 Same group.

[0464] As through Ra 01 ~Ra 03 In the group containing a carbon-carbon double bond, two or more of the carbon-carbon double bond are bonded to each other to form a cyclic structure, for example, cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, cyclopentylidene vinyl, cyclohexylidene vinyl, etc. can be mentioned. Among these, from the viewpoint of the ease of synthesis of the monomer compound from which the structural unit (a1) is derived, cyclopentenyl, cyclohexenyl, and cyclopentylidene vinyl are preferred.

[0465] In the formula (a1-r2-3), the aliphatic cyclic group formed together with Xaa and Yaa is preferably the same as Ra' in the formula (a1-r-1). 3 The group mentioned above is an aliphatic hydrocarbon group (a monocyclic group or a polycyclic group).

[0466] In formula (a1-r2-3), as Ra 04 The aromatic hydrocarbon group in Ra includes a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 04 Preferably, it is a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably, it is a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, further preferably, it is a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably, it is a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably, it is a group obtained by removing one or more hydrogen atoms from benzene.

[0467] As Ra in formula (a1-r2-3) 04 Examples of the substituent that may be possessed include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), and an alkyloxycarbonyl group.

[0468] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each independently represents a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. 12 and Ra' 13 The monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the formula (a) may be any of the following: 01 ~Ra 03 The group is the same as the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. A part or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted.

[0469] Among them, Ra' 12 and Ra' 13 It is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0470] The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by is substituted, as the substituent, for example, the same as Ra as above can be mentioned. 05 Same group.

[0471] In formula (a1-r2-4), Ra'14 is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0472] Ra' 14 The number of carbon atoms of the linear alkyl group in is preferably 1 to 5, more preferably 1 to 4, and further preferably 1 or 2. Specifically, methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc. are mentioned. Among these, methyl, ethyl or n-butyl is preferred, and methyl or ethyl is more preferred.

[0473] Ra' 14 The number of carbon atoms of the branched alkyl group in is preferably 3 to 10, more preferably 3 to 5. Specific examples thereof include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl, and isopropyl is preferred.

[0474] Ra' 14 In the case of a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0475] The aliphatic hydrocarbon group as a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0476] The aliphatic hydrocarbon group as the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0477] As Ra' 14 The aromatic hydrocarbon group in Ra includes 04 The same group as the aromatic hydrocarbon group in 14 Preferably, it is a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably, it is a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, further preferably, it is a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably, it is a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably, it is a group obtained by removing one or more hydrogen atoms from naphthalene.

[0478] As Ra' 14 The substituents that may be present include 04 The substituents which may be present are the same group.

[0479] Ra' in formula (a1-r2-4) 14 In the case of a naphthyl group, the position at which the group bonds to the tertiary carbon atom in the above formula (a1-r2-4) may be either the 1-position or the 2-position of the naphthyl group.

[0480] Ra' in formula (a1-r2-4) 14 In the case of an anthracene group, the position at which the anthracene group bonds to the tertiary carbon atom in the above formula (a1-r2-4) may be any of the 1-position, 2-position, or 9-position of the anthracene group.

[0481] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0482] [Chemical formula 10]

[0483]

[0484] [Chemical formula 11]

[0485]

[0486] [Chemical formula 12]

[0487]

[0488] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0489] [Chemical formula 13]

[0490]

[0491] [Chemical formula 14]

[0492]

[0493] [Chemical formula 15]

[0494]

[0495] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0496] [Chemical formula 16]

[0497]

[0498] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0499] [Chemical formula 17]

[0500]

[0501] Tertiary alkyloxycarbonyl acid dissociative group:

[0502] Examples of the acid-dissociable group for protecting the hydroxyl group in the polar group include acid-dissociable groups represented by the following general formula (a1-r-3) (hereinafter, sometimes referred to as "tertiary alkyloxycarbonyl acid-dissociable group" for convenience).

[0503] [Chemical formula 18]

[0504]

[0505] [where Ra' 7 ~Ra' 9 Each is an alkyl group.]

[0506] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

[0507] The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0508] The structural unit (a1) includes: a structural unit derived from an acrylate in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent; a structural unit derived from acrylamide; a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of hydroxystyrene or a structural unit derived from hydroxystyrene is protected by a substituent containing the above-mentioned acid-decomposable group; a structural unit in which at least a part of the hydrogen atoms in the -C(=O)-OH of a structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative is protected by a substituent containing the above-mentioned acid-decomposable group; and the like.

[0509] As the structural unit (a1), among the above, a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position may be substituted by a substituent is preferred. As a preferred specific example of the structural unit (a1), there can be mentioned the structural unit represented by the following general formula (a1-1) or (a1-2).

[0510] [Chemical formula 19]

[0511]

[0512] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 1 It is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 Wa is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1) or (a1-r-2).1 n a2 +1-valent hydrocarbon group, n a2 is an integer from 1 to 3, Ra 2 It is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1) or (a1-r-3).]

[0513] In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. can be mentioned. The haloalkyl group having 1 to 5 carbon atoms is a group obtained by replacing a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms with halogen atoms. As the halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom, etc. can be mentioned, and fluorine atom is particularly preferred.

[0514] R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in view of industrial availability.

[0515] In the above formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0516] As Va 1 The aliphatic hydrocarbon group of the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated.

[0517] More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure.

[0518] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specifically, a methylene group [—CH 2 -], ethylene [-(CH 2 ) 2 -], trimethylene [-(CH 2 ) 3 -], tetramethylene [-(CH 2 ) 4 -], pentamethylene [-(CH 2 ) 5 -]wait.

[0519] The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH 3 )-、-CH(CH 2 CH 3 )-、-C(CH 3 ) 2 -、-C(CH 3 )(CH 2 CH 3 )-、-C(CH 3 )(CH 2 CH 2 CH 3 )-、-C(CH 2 CH 3 ) 2 -alkylmethylene; -CH(CH 3 )CH 2 -、-CH(CH 3 )CH(CH 3 )-、-C(CH 3 ) 2 CH 2 -、-CH(CH 2 CH 3 )CH 2 -、-C(CH 2 CH 3 ) 2 -CH 2 -alkylethylene; -CH(CH 3 )CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 -Alkyl trimethylene; -CH(CH 3 )CH 2 CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 CH 2 -, etc., alkyltetramethylene, etc., etc. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0520] Examples of the aliphatic hydrocarbon group containing a ring in the above structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group obtained by bonding an alicyclic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed between a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same groups as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.

[0521] The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

[0522] The above-mentioned alicyclic hydrocarbon group may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclopentane, cyclohexane, etc. can be mentioned. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

[0523] As Va 1 The aromatic hydrocarbon group of the divalent hydrocarbon group in is a hydrocarbon group having an aromatic ring.

[0524] The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. The number of carbon atoms does not include the number of carbon atoms in the substituent. Specifically, the aromatic ring possessed by the aromatic hydrocarbon group includes aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings obtained by replacing a part of the carbon atoms constituting the above aromatic hydrocarbon rings with heteroatoms, etc. The heteroatoms in the aromatic heterocyclic ring include oxygen atoms, sulfur atoms, nitrogen atoms, etc.

[0525] Specific examples of the aromatic hydrocarbon group include: a group obtained by removing two hydrogen atoms from the above aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the above aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by further removing one hydrogen atom from an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms in the above alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0526] In the above formula (a1-1), Ra 1It is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0527] In the above formula (a1-2), Wa 1 n a2 The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that is not aromatic and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a group obtained by combining a linear or branched aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in the structure. a2 The +1 valence is preferably 2-4 valence, more preferably 2- or 3-valence.

[0528] In the above formula (a1-2), Ra 2 It is an acid-dissociable group represented by the above-mentioned general formula (a1-r-1) or (a1-r-3).

[0529] Specific examples of the structural unit represented by the above formula (a1-1) are shown below. α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0530] [Chemical formula 20]

[0531]

[0532] [Chemical formula 21]

[0533]

[0534] [Chemical formula 22]

[0535]

[0536] [Chemical formula 23]

[0537]

[0538] [Chemical formula 24]

[0539]

[0540] [Chemical formula 25]

[0541]

[0542] [Chemical formula 26]

[0543]

[0544] [Chemical formula 27]

[0545]

[0546] [Chemical formula 28]

[0547]

[0548] [Chemical formula 29]

[0549]

[0550] [Chemical formula 30]

[0551]

[0552] Specific examples of the structural unit represented by the above formula (a1-2) are shown below.

[0553] [Chemical formula 31]

[0554]

[0555] The structural unit (a1) contained in the component (A1) may be one type or two or more types.

[0556] As the structural unit (a1), the structural unit represented by the above formula (a1-1) is more preferable because it is easier to improve the characteristics (sensitivity, shape, etc.) under electron beam or EUV lithography.

[0557] Among them, as the structural unit (a1), it is particularly preferred to contain a structural unit represented by the following general formula (a1-1-1).

[0558] [Chemical formula 32]

[0559]

[0560] [where Ra 1 " is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).]

[0561] In the above formula (a1-1-1), R, Va 1 and n a1 R and Va in the above formula (a1-1) 1 and n a1 same.

[0562] The acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above.

[0563] From the perspective of improving the effects of the present invention, the proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, and further preferably 30 to 70 mol%, relative to the total (100 mol%) of all structural units constituting the component (A1).

[0564] [Structural unit (a10) containing a hydroxystyrene skeleton]

[0565] The component (A1) preferably has a structural unit (a10) containing a hydroxystyrene skeleton in addition to the structural unit (a1).

[0566] As the structural unit (a10), for example, a structural unit represented by the following general formula (a10-1) is preferably mentioned.

[0567] [Chemical formula 33]

[0568]

[0569] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1 for (n ax1 +1) valent aromatic hydrocarbon group. ax1 is an integer from 1 to 3.]

[0570] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.

[0571] The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, etc. can be mentioned. The haloalkyl group having 1 to 5 carbon atoms of R is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are replaced by halogen atoms. As the halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom, etc. can be mentioned, and fluorine atom is particularly preferred.

[0572] R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group in view of industrial availability.

[0573] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group.

[0574] As Ya x1The divalent linking group in the present invention is preferably a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom.

[0575] ·Divalent hydrocarbon group which may have a substituent:

[0576] Ya x1 In the case of a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0577] ··Ya x1 Aliphatic hydrocarbon groups

[0578] The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. As the above-mentioned aliphatic hydrocarbon group, a straight-chain or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure, etc. can be cited.

[0579] ···Straight-chain or branched aliphatic hydrocarbon group

[0580] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

[0581] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specific examples thereof include a methylene group [—CH 2 -], ethylene [-(CH 2 ) 2 -], trimethylene [-(CH 2 ) 3 -], tetramethylene [-(CH 2 ) 4 -], pentamethylene [-(CH 2 ) 5 -]wait.

[0582] The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.

[0583] The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include -CH(CH 3 )-、-CH(CH 2 CH 3 )-、-C(CH 3 ) 2 -、-C(CH 3 )(CH 2 CH 3 )-、-C(CH 3 )(CH2 CH 2 CH 3 )-、-C(CH 2 CH 3 ) 2 -alkylmethylene; -CH(CH 3 )CH 2 -、-CH(CH 3 )CH(CH 3 )-、-C(CH 3 ) 2 CH 2 -、-CH(CH 2 CH 3 )CH 2 -、-C(CH 2 CH 3 ) 2 -CH 2 -alkylethylene; -CH(CH 3 )CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 -Alkyl trimethylene; -CH(CH 3 )CH 2 CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 CH 2 -, etc., alkyltetramethylene, etc., etc. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0584] The above-mentioned linear or branched aliphatic hydrocarbon group may or may not have a substituent, and examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

[0585] Aliphatic hydrocarbon groups containing rings in their structures

[0586] Examples of the aliphatic hydrocarbon group containing a ring in the structure include: a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure; a group obtained by bonding the above cyclic aliphatic hydrocarbon group to the terminal of a linear or branched aliphatic hydrocarbon group; a group in which the above cyclic aliphatic hydrocarbon group is interposed between a linear or branched aliphatic hydrocarbon group; etc. Examples of the above linear or branched aliphatic hydrocarbon group include the same groups as described above.

[0587] The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms.

[0588] The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclopentane, cyclohexane, etc. can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

[0589] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.

[0590] The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.

[0591] The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, and a tert-butoxy group, and most preferably a methoxy group and an ethoxy group.

[0592] Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferred.

[0593] Examples of the halogenated alkyl group as the substituent include groups in which a part or all of the hydrogen atoms of the above-mentioned alkyl group are substituted with the above-mentioned halogen atoms.

[0594] In the case of a cyclic aliphatic hydrocarbon group, a portion of the carbon atoms constituting the ring structure may be replaced by a substituent containing a heteroatom. The substituent containing a heteroatom is preferably -O-, -C(=O)-O-, -S-, -S(=O)- 2 -、-S(=O) 2 -O-.

[0595] ··Ya x1 Aromatic hydrocarbon groups

[0596] The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0597] The aromatic ring is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons, and can be a monocyclic or polycyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Among them, the number of carbon atoms does not include the number of carbon atoms in the substituent. As the aromatic ring, specifically, there can be mentioned: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the above aromatic hydrocarbon rings are substituted by heteroatoms, etc. As heteroatoms in the aromatic heterocyclic ring, there can be mentioned oxygen atoms, sulfur atoms, nitrogen atoms, etc. As aromatic heterocyclic rings, specifically, there can be mentioned pyridine rings, thiophene rings, etc.

[0598] Specific examples of the aromatic hydrocarbon group include: a group obtained by removing two hydrogen atoms from the above aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group obtained by removing one hydrogen atom from the above aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) in which one hydrogen atom is replaced by an alkylene group (e.g., a group obtained by further removing one hydrogen atom from an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The alkylene group bonded to the above aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0599] In the case of the aromatic hydrocarbon group, the hydrogen atom possessed by the aromatic hydrocarbon group may be substituted by a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted by a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

[0600] The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

[0601] As for the alkoxy group, the halogen atom and the halogenated alkyl group as the above-mentioned substituent, the groups exemplified as the substituents replacing the hydrogen atom which the above-mentioned cyclic aliphatic hydrocarbon group has can be mentioned.

[0602] ·Divalent linking groups containing heteroatoms:

[0603] Ya x1In the case of a divalent linking group containing a heteroatom, preferred groups as the linking group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group), -S-, -S(=O)- 2 -、-S(=O) 2 -O-, general formula -Y 21 -OY 22 -、-Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -、-[Y 21 -C(=O)-O] m” -Y 22 -、-Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -represented by a group [wherein, Y 21 and Y 22 Each is independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3.]

[0604] When the above-mentioned divalent linking group containing a heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, its H may be substituted by a substituent such as an alkyl group or an acyl group. The number of carbon atoms of the substituent (alkyl group, acyl group, etc.) is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5.

[0605] General formula-Y 21 -OY 22 -、-Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -、-[Y 21 -C(=O)-O] m” -Y 22 -、-Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -Medium,Y 21 and Y 22Each is independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those exemplified in the description of the divalent linking group (divalent hydrocarbon group which may have a substituent).

[0606] As Y 21 , preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, further preferably a straight-chain alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group.

[0607] As Y 22 , preferably a straight-chain or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

[0608] Formula-[Y 21 -C(=O)-O] m” -Y 22 -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, as the formula -[Y 21 -C(=O)-O] m” -Y 22 -represented group, especially preferably the group of formula -Y 21 -C(=O)-OY 22 -represented by a group. Among them, the preferred formula is -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’ -. In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1.

[0609] As Ya x1 , preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), —C(═O)—NH—, a linear or branched alkylene group, or a combination thereof, among which a single bond is particularly more preferred.

[0610] In the above formula (a10-1), Wa x1 for (n ax1 +1) valent aromatic hydrocarbon group.

[0611] As Wa x1 The aromatic hydrocarbon group in the present invention may be a hydrocarbon group which is obtained by removing (n ax1+1) hydrogen atoms. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons, and can be a monocyclic or polycyclic type. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. As the aromatic ring, specifically, there can be mentioned: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the above aromatic hydrocarbon rings are substituted by heteroatoms, etc. As heteroatoms in the aromatic heterocyclic ring, there can be mentioned oxygen atoms, sulfur atoms, nitrogen atoms, etc. As the aromatic heterocyclic ring, specifically, there can be mentioned pyridine rings, thiophene rings, etc.

[0612] In the above formula (a10-1), n ax1 It is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

[0613] Specific examples of the structural unit represented by the general formula (a10-1) are shown below.

[0614] In the following formula, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0615] [Chemical formula 34]

[0616]

[0617] The structural unit (a10) contained in the component (A1) may be one type or two or more types.

[0618] In the component (A1), from the perspective of improving the effect of the present invention, the proportion of the structural unit (a10) relative to the total (100 mol%) of all structural units constituting the component (A1) is, for example, 0 to 80 mol%, preferably 10 to 80 mol%, more preferably 20 to 70 mol%, and particularly preferably 30 to 60 mol%.

[0619] [Structural unit (a2)]

[0620] The component (A1) may have, in addition to the structural unit (a1), the following structural unit (a2) (excluding the structural unit belonging to the structural unit (a1)), wherein the structural unit (a2) contains a cyclic group containing a lactone, a -SO 2 -cyclic group or a cyclic group containing carbonate.

[0621] When the component (A1) is used for forming a resist film, the lactone-containing cyclic group of the structural unit (a2) and the -SO-containing 2-cyclic group or the cyclic group containing carbonate are effective in improving the adhesion of resist film and substrate. In addition, by having structural unit (a2), by for example appropriately adjusting the acid diffusion length, improving the adhesion of resist film and substrate, appropriately adjusting the solubility during development, improving the etching resistance, so that photolithography characteristics etc. become good.

[0622] The so-called "cyclic group containing lactone" refers to a cyclic group containing the following ring (lactone ring), wherein the ring contains -OC(=O)- in its ring skeleton. The lactone ring is recorded as the first ring. When there is only a lactone ring, it is called a monocyclic group. When there are other ring structures, regardless of their structures, it is called a polycyclic group. The cyclic group containing lactone may be a monocyclic group or a polycyclic group.

[0623] As the lactone-containing cyclic group in the structural unit (a2), any group can be used without particular limitation. Specifically, groups represented by the following general formulae (a2-r-1) to (a2-r-7) are mentioned.

[0624] [Chemical formula 35]

[0625]

[0626] [where Ra' 21 Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a cyclic group containing a lactone, a cyclic group containing a carbonate, or a cyclic group containing -SO 2 -cyclic group; A" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom which may contain an oxygen atom (-O-) or a sulfur atom (-S-), n' is an integer of 0 to 2, and m' is 0 or 1.]

[0627] In the above general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in the formula (A) is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, etc. are mentioned. Among these, methyl or ethyl is preferred, and methyl is particularly preferred.

[0628] As Ra' 21 The alkoxy group in the formula (A) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, Ra' 21 The alkyl group in the example is a group obtained by bonding an alkyl group to an oxygen atom (—O—).

[0629] As Ra' 21 The halogen atom in includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferred.

[0630] As Ra' 21 The halogenated alkyl group in the above Ra' 21 A group obtained by replacing a part or all of the hydrogen atoms of the alkyl group with the above-mentioned halogen atoms. As the halogenated alkyl group, a fluoroalkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0631] Ra' 21 In the "-COOR" and "-OC(=O)R", R" is a hydrogen atom, an alkyl group, a cyclic group containing a lactone, a cyclic group containing a carbonate, or a cyclic group containing -SO 2 -cyclic group.

[0632] The alkyl group in R" may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.

[0633] When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

[0634] When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably has 4 to 12 carbon atoms, and most preferably has 5 to 10 carbon atoms. Specifically, examples include: a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may be substituted with a fluorine atom or a fluoroalkyl group or may not be substituted; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, a tetracycloalkane, etc.; and the like. More specifically, examples include: a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0635] Examples of the lactone-containing cyclic group in R" include the same groups as those represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7).

[0636] The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by general formulae (ax3-r-1) to (ax3-r-3) are mentioned.

[0637] As R" contains -SO 2 -, and the cyclic group containing -SO described later 2- similarly, specific examples include groups represented by general formulae (a5-r-1) to (a5-r-4).

[0638] As Ra' 21 The hydroxyalkyl group in the above is preferably a hydroxyalkyl group having 1 to 6 carbon atoms, and specifically, the above Ra' 21 A group obtained by replacing at least one hydrogen atom of the alkyl group with a hydroxy group.

[0639] In the above general formulas (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include methylene, ethylene, n-propylene, isopropylene and the like. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups having -O- or -S- at the end of the alkylene group or between carbon atoms, such as -O-CH 2 -、-CH 2 -O-CH 2 -、-S-CH 2 -、-CH 2 -S-CH 2 - etc. As A", preferably, an alkylene group having 1 to 5 carbon atoms or -O- is present, more preferably, an alkylene group having 1 to 5 carbon atoms is present, and most preferably, a methylene group is present.

[0640] Specific examples of the groups represented by general formulae (a2-r-1) to (a2-r-7) are given below.

[0641] [Chemical formula 36]

[0642]

[0643] [Chemical formula 37]

[0644]

[0645] The so-called "containing -SO 2 -cyclic group" means a group containing -SO in its ring skeleton 2 -, specifically, -SO 2 - is a cyclic group in which the sulfur atom (S) in the cyclic group forms a part of the ring skeleton of the cyclic group. 2 - is referred to as the first ring. If there is only this ring, it is called a monocyclic group. If there are other ring structures, regardless of their structures, it is called a polycyclic group. 2 -The cyclic group may be a monocyclic group or a polycyclic group. 2-cyclic group is particularly preferably a cyclic group containing -O-SO in its ring skeleton 2 -cyclic groups, i.e., containing -O-SO 2 -OS- in - is a cyclic group of a sultone ring in which the -OS- forms a part of the ring skeleton.

[0646] As containing -SO 2 -, more specifically, groups represented by the following general formulae (a5-r-1) to (a5-r-4) are mentioned.

[0647] [Chemical formula 38]

[0648]

[0649] [where Ra' 51 Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 - contains a cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2.]

[0650] In the above general formulae (a5-r-1) to (a5-r-2), A" is the same as A" in the above general formulae (a2-r-2), (a2-r-3) and (a2-r-5).

[0651] As Ra' 51 The alkyl, alkoxy, halogen atom, halogenated alkyl, -COOR", -OC(=O)R", hydroxyalkyl in the above general formula (a2-r-1) to (a2-r-7) can be exemplified as Ra' 21 The same groups as those mentioned in the description of .

[0652] Specific examples of the groups represented by general formulae (a5-r-1) to (a5-r-4) are given below: "Ac" in the formulae represents an acetyl group.

[0653] [Chemical formula 39]

[0654]

[0655] [Chemical formula 40]

[0656]

[0657] [Chemical formula 41]

[0658]

[0659] The so-called "cyclic group containing carbonate" means a cyclic group containing the following ring (carbonate ring), wherein the ring contains -OC(=O)-O- in its ring skeleton. The carbonate ring is recorded as the first ring. In the case of only the carbonate ring, it is called a monocyclic group. In the case of having other ring structures, regardless of the structure, it is called a polycyclic group. The cyclic group containing carbonate can be a monocyclic group or a polycyclic group.

[0660] As the cyclic group containing a carbonate ring, any group can be used without particular limitation. Specifically, groups represented by the following general formulae (ax3-r-1) to (ax3-r-3) are mentioned.

[0661] [Chemical formula 42]

[0662]

[0663] [where Ra' x31 Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 - contains a cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, p' is an integer of 0 to 3, and q' is 0 or 1.]

[0664] In the above general formulas (ax3-r-2) to (ax3-r-3), A" is the same as A" in the above general formulas (a2-r-2), (a2-r-3) and (a2-r-5).

[0665] As Ra' 31 The alkyl, alkoxy, halogen atom, halogenated alkyl, -COOR", -OC(=O)R", hydroxyalkyl in the above general formula (a2-r-1) to (a2-r-7) can be exemplified as Ra' 21 The same groups as those mentioned in the description of .

[0666] Specific examples of the groups represented by general formulae (ax3-r-1) to (ax3-r-3) are given below.

[0667] [Chemical formula 43]

[0668]

[0669] Among them, the structural unit (a2) is preferably a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent.

[0670] The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0671] [Chemical formula 44]

[0672]

[0673] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 21 is a single bond or a divalent linking group. 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, R' represents a hydrogen atom or a methyl group. 21 When it is -O-, Ya 21 Not -CO-. 21 is a cyclic group containing a lactone, a cyclic group containing a carbonate, or a cyclic group containing -SO 2 -cyclic group.]

[0674] In the above formula (a2-1), R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 5 carbon atoms, and particularly preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0675] In the above formula (a2-1), as Ya 21 The divalent linking group of Ya is not particularly limited, and preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. 21 The descriptions of the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom are respectively the same as those for Ya in the above general formula (a10-1). x1 The same applies to the description of the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom.

[0676] As Ya 21 , preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.

[0677] In the above formula (a2-1), Ra 21 A cyclic group containing lactone, containing -SO 2 -cyclic group or a cyclic group containing carbonate.

[0678] As Ra 21 The lactone-containing cyclic group, -SO 2-cyclic groups and cyclic groups containing carbonates, preferably groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), groups represented by the general formulae (a5-r-1) to (a5-r-4), and groups represented by the general formulae (ax3-r-1) to (ax3-r-3).

[0679] Among them, a cyclic group containing lactone or a cyclic group containing -SO 2 -cyclic group, more preferably a group represented by the above general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1). Specifically, it is more preferably any group represented by the above chemical formulas (R-LC-1-1) to (R-LC-1-7), (R-LC-2-1) to (R-LC-2-18), (R-LC-6-1), (R-SL-1-1), (R-SL-1-18).

[0680] The structural unit (a2) contained in the component (A1) may be one type or two or more types.

[0681] When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) relative to the total of all structural units constituting the component (A1) (100 mol%) is preferably 0 to 50 mol%, more preferably 5 to 45 mol%, further preferably 10 to 40 mol%, and particularly preferably 10 to 30 mol%.

[0682] When the ratio of the structural unit (a2) is at least the preferred lower limit, the effect of containing the structural unit (a2) can be sufficiently obtained, while when it is at most the upper limit, a balance with other structural units can be obtained, and various lithography characteristics become good.

[0683] [Structural unit (a3)]

[0684] The component (A1) may have a structural unit (a3) ​​containing an aliphatic hydrocarbon group containing a polar group in addition to the structural unit (a1) (but excluding structural units belonging to the structural unit (a1) and the structural unit (a2)). When the component (A1) has the structural unit (a3), the photolithographic characteristics become good due to the effects such as appropriately adjusting the acid diffusion length, improving the adhesion between the resist film and the substrate, appropriately adjusting the solubility during development, and improving the etching resistance.

[0685] Examples of the polar group include a hydroxyl group, a cyano group, a carboxyl group, and a hydroxyalkyl group (wherein a part of hydrogen atoms of the alkyl group is substituted with fluorine atoms). Among them, a hydroxyl group is preferred.

[0686] As the aliphatic hydrocarbon group, there can be mentioned a straight-chain or branched hydrocarbon group (preferably an alkylene group) having 1 to 10 carbon atoms, and a cyclic aliphatic hydrocarbon group (cyclic group). As the cyclic group, it can be a monocyclic group or a polycyclic group, for example, it can be appropriately selected from the cyclic groups mentioned many times in the resin for the ArF excimer laser resist composition and used. As the cyclic group, a polycyclic group is preferred, and the number of carbon atoms is more preferably 7 to 30.

[0687] Among them, more preferably a structural unit derived from an acrylate containing an aliphatic polycyclic group, the aliphatic polycyclic group contains a hydroxyl, cyano, carboxyl or alkyl part of the hydrogen atoms are replaced by fluorine atoms to obtain a hydroxyalkyl. As the polycyclic group, examples can be given of groups obtained by removing more than 2 hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specifically, groups obtained by removing more than 2 hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be cited. Among these polycyclic groups, industrially preferably a group obtained by removing more than 2 hydrogen atoms from adamantane, a group obtained by removing more than 2 hydrogen atoms from norbornane, and a group obtained by removing more than 2 hydrogen atoms from tetracyclododecane.

[0688] As the structural unit (a3), any structural unit can be used without particular limitation as long as it contains an aliphatic hydrocarbon group containing a polar group.

[0689] The structural unit (a3) ​​is preferably a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent and which contains an aliphatic hydrocarbon group having a polar group.

[0690] As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from hydroxyethyl acrylic acid is preferred.

[0691] In addition, as the structural unit (a3), when the hydrocarbon group in the aliphatic hydrocarbon group containing a polar group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-3) can be listed as preferred structural units.

[0692] [Chemical formula 45]

[0693]

[0694] [In the formula, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 1 to 5, and s is an integer of 1 to 3.]

[0695] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, the hydroxyl group is preferably bonded to the 3-position and 5-position of the adamantyl group. When j is 1, the hydroxyl group is preferably bonded to the 3-position of the adamantyl group. j is preferably 1, and it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0696] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or 6-position of the norbornyl group.

[0697] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. Preferably, a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxyl group of acrylic acid. The fluoroalkyl alcohol is preferably bonded to the 5-position or 6-position of the norbornyl group.

[0698] The structural unit (a3) ​​contained in the component (A1) may be one type or two or more types.

[0699] When the component (A1) has the structural unit (a3), the amount thereof is preferably 0 to 40 mol %, more preferably 2 to 30 mol %, further preferably 5 to 25 mol %, and particularly preferably 5 to 20 mol %, based on the total of all the structural units constituting the component (A1).

[0700] When the ratio of the structural unit (a3) ​​is at least the preferred lower limit, the effect of containing the structural unit (a3) ​​can be fully obtained, and when it is at most the upper limit, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0701] 〔Structural unit (6)〕

[0702] The component (A1) may have a structural unit (a6) that generates an acid upon exposure, in addition to the structural unit (a1).

[0703] The structural unit (a6) is not particularly limited as long as it is a structural unit that generates an acid upon exposure. For example, the following structural unit can be used: a structural unit that can be copolymerized with the above-mentioned structural unit (a1) and has a structure proposed as an acid generator for conventional chemically amplified resists.

[0704] Preferred examples of the structural unit copolymerizable with the structural unit (a1) and the like include a structural unit derived from a (meth)acrylic acid ester and a structural unit derived from a hydroxystyrene.

[0705] As the structural unit introduced with a structure proposed as an acid generator for a conventional chemically amplified resist, a structural unit introduced with a structure of the component (B) described later can be cited as a preferred structural unit.

[0706] Examples of the structural unit (a6) include a structural unit (a6a) having an anionic group generating an acid by exposure to light in a side chain, or a structural unit (a6c) having a cationic group decomposing by exposure to light in a side chain.

[0707] About structural unit (a6a)

[0708] The structural unit (a6a) is a structural unit having an anionic group that generates an acid upon exposure in a side chain.

[0709] The anion group that generates an acid upon exposure is not particularly limited, but preferably is a sulfonate anion, an amide anion, or a methide anion. Among them, the structural unit (a6a) is preferably a structural unit having an anion group represented by the following general formula (a6a-r-11).

[0710] [Chemical formula 46]

[0711]

[0712] [Where R f1 and R f2 are each independently a hydrogen atom, an alkyl group, a fluorine atom or a fluoroalkyl group, R f1 and R f2 At least one of them is a fluorine atom or a fluorinated alkyl group, and p0 is an integer of 1 to 8.]

[0713] In the above formula (a6a-r-11), R f1 and R f2 are each independently a hydrogen atom, an alkyl group, a fluorine atom or a fluoroalkyl group, R f1 and R f2 At least one of them is a fluorine atom or a fluorinated alkyl group.

[0714] As R f1 and R f2 The alkyl group in is preferably an alkyl group having 1 to 5 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl and neopentyl.

[0715] As R f1 and R f2 The fluoroalkyl group in the above R f1 , R f2 A group obtained by replacing a part or all of the hydrogen atoms of an alkyl group with fluorine atoms.

[0716] As R f1 and R f2 , each independently preferably a fluorine atom or a fluorinated alkyl group.

[0717] In the above formula (a6a-r-11), p0 is an integer of 1 to 8, preferably an integer of 1 to 4, and more preferably 1 or 2.

[0718] Examples of cations that can form salts with the anionic group of the structural unit (a6a) include organic cations. There are no particular limitations on the organic cations, but onium cations are preferred, sulfonium cations and iodonium cations are more preferred, and organic cations represented by the general formulas (ca-1) to (ca-4) described below are particularly preferred.

[0719] Specific examples of the structural unit having an anionic group represented by the above formula (a6a-r-11) are shown below. α represents a hydrogen atom, a methyl group or a trifluoromethyl group. m+ ) 1 / m It represents an m-valent organic cation that forms a salt with an anionic group.

[0720] [Chemical formula 47]

[0721]

[0722] About structural unit (a6c)

[0723] The structural unit (a6c) is a structural unit having a cationic group that is decomposed by exposure in a side chain.

[0724] The cationic group decomposed by exposure is not particularly limited, but a group represented by the following general formula (a6c-r-1) is preferred.

[0725] [Chemical formula 48]

[0726]

[0727] [where Ra' 61c and Ra' 62c Each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 61c represents an arylene group, an alkylene group or an alkenylene group. 61c , Ra' 62c and Va' 61c They may be bonded to each other to form a ring together with the sulfur atom in the formula.]

[0728] In the above formula (a6c-r-1), Ra' 61c and Ra' 62c Each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 61c and Ra' 62cAs for R, there can be mentioned the following: 201 ~R 203 The same groups as the aryl group which may have a substituent, the alkyl group which may have a substituent, or the alkenyl group which may have a substituent.

[0729] Va' 61c represents an arylene group, an alkylene group or an alkenylene group, and examples thereof include Ra' 61c and Ra' 62c A group obtained by removing one hydrogen atom from an aryl, alkyl or alkenyl group.

[0730] Among them, Ra' 61c , Ra' 62c and Va' 61c They may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring structure formed here includes R in the formula (ca-1) described later. 201 ~R 203 A group obtained by removing one hydrogen atom from a ring formed by bonding to each other together with the sulfur atom in the formula.

[0731] There are no particular limitations on the anion that can form a salt with the cationic portion of the structural unit (a6c), and examples include the anion portion of an onium salt-based acid generator represented by the general formula (b-1), (b-2) or (b-3) exemplified in the description of the component (B) described later. The anion portion of an onium salt-based acid generator represented by the general formula (b-1) is particularly preferred, and is preferably at least one of the anions selected from fluoroalkylsulfonate ions having 1 to 8 carbon atoms (preferably having 1 to 4 carbon atoms) or the anions represented by the general formulas (an-1) to (an-3) described later.

[0732] Specific examples of the structural unit having a cationic group represented by the above formula (a6c-r-1) are shown below. α represents a hydrogen atom, a methyl group or a trifluoromethyl group. - It represents the counter anion that forms a salt with a cationic group.

[0733] [Chemical formula 49]

[0734]

[0735] The structural unit (a6) contained in the component (A1) may be one type or two or more types.

[0736] In the component (A1), the proportion of the structural unit (a6) is preferably 0 to 30 mol %, more preferably 1 to 20 mol %, and particularly preferably 1.5 to 15 mol % based on the total of all structural units constituting the component (A1).

[0737] By making the ratio of the structural unit (a6) equal to or greater than the lower limit, the roughness is reduced and a good resist pattern shape is easily obtained. By making it equal to or less than the upper limit, a balance with other structural units can be achieved, and the lithography characteristics are further improved.

[0738] 〔Other structural units〕

[0739] The component (A1) may have a structural unit other than the structural unit (a1), the structural unit (a10), the structural unit (a2), the structural unit (a3), and the structural unit (a6) described above.

[0740] As other structural units, for example, there can be mentioned the structural unit (a9) represented by the general formula (a9-1) described later, structural units derived from styrene, structural units derived from styrene derivatives (excluding those belonging to the structural unit (a10)), structural units containing acid-non-dissociable aliphatic cyclic groups, etc.

[0741] Structural unit (a9):

[0742] The structural unit (a9) is a structural unit represented by the following general formula (a9-1).

[0743] [Chemical formula 50]

[0744]

[0745] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 91 Is a single bond or a divalent linking group. 92 is a divalent linking group. 91 is a hydrocarbon group which may have a substituent.]

[0746] In the above formula (a9-1), R is the same as described above.

[0747] R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and particularly preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0748] In the above formula (a9-1), Ya 91 The divalent linking group in the formula (a10-1) may be x1 The same group as the divalent connecting group. 91 , preferably a single bond.

[0749] In the above formula (a9-1), Ya 92 The divalent linking group may be a group that is similar to Ya in the general formula (a10-1) x1The divalent connecting group is the same group.

[0750] Ya 92 Among the divalent linking groups, the divalent hydrocarbon group which may have a substituent is preferably a linear or branched aliphatic hydrocarbon group.

[0751] In addition, Ya 92 Examples of the divalent linking groups containing a heteroatom include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group), -S-, -S(=O)- 2 -、-S(=O) 2 -O-, -C(=S)-, general formula -Y 21 -OY 22 -、-Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O--Y 21 , [Y 21 -C(=O)-O] m’ -Y 22 -or-Y 21 -OC(=O)-Y 22 -represented by a group [wherein, Y 21 and Y 22 Each is independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m' is an integer of 0 to 3. ] etc. Among them, -C(=O)- and -C(=S)- are preferred.

[0752] In the above formula (a9-1), R 91 Examples of the hydrocarbon group include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, and an aralkyl group.

[0753] R 91 The alkyl group in is preferably a group having 1 to 8 carbon atoms, more preferably a group having 1 to 6 carbon atoms, and still more preferably a group having 1 to 4 carbon atoms, and may be linear or branched. Specifically, methyl, ethyl, propyl, butyl, hexyl, octyl, etc. are preferred.

[0754] R 91The monovalent alicyclic hydrocarbon group in is preferably a group having 3 to 20 carbon atoms, more preferably a group having 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclobutane, cyclopentane, cyclohexane, etc. can be mentioned. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 12 carbon atoms is preferred, and specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

[0755] R 91 The aryl group in the aryl group preferably has 6 to 18 carbon atoms, more preferably 6 to 10 carbon atoms, and specifically, a phenyl group is particularly preferred.

[0756] As R 91 The aralkyl group in the above-mentioned "R 91 The aryl group in "R" is preferably an alkylene group having 1 to 6 carbon atoms and the above "R 91 The aryl group in the above "R" is preferably an alkylene group having 1 to 4 carbon atoms and the above "R 91 The arylalkyl group obtained by bonding with the "aryl group" in the

[0757] Just R 91 For the hydrocarbon group in the above, it is preferred that part or all of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms, and more preferably 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. Among them, a perfluoroalkyl group in which all the hydrogen atoms of the above alkyl group are substituted with fluorine atoms is particularly preferred.

[0758] R 91 The hydrocarbon group in the formula (a) may have a substituent. Examples of the substituent include a halogen atom, an oxo group (=O), a hydroxyl group (-OH), an amino group (-NH 2 ),-SO 2 -NH 2 In addition, a part of the carbon atoms constituting the hydrocarbon group may be replaced by a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -NH-, -N=, -C(=O)-O-, -S-, -S(=O) 2 -、-S(=O) 2 -O-.

[0759] R 91 In the above, examples of the hydrocarbon group having a substituent include lactone-containing cyclic groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), respectively.

[0760] In addition, R 91 In the above, examples of the hydrocarbon group having a substituent include: each of the above general formulas (a5-r-1) to (a5-r-4) containing -SO 2 -cyclic group; substituted aryl group represented by the following chemical formula, monovalent heterocyclic group, etc.

[0761] [Chemical formula 51]

[0762]

[0763] Among the structural units (a9), the structural units represented by the following general formula (a9-1-1) are preferred.

[0764] [Chemical formula 52]

[0765]

[0766] [where R is the same as above, Ya 91 is a single bond or a divalent linking group, R 91 is a hydrocarbon group which may have a substituent, R 92 is an oxygen atom or a sulfur atom.]

[0767] In the general formula (a9-1-1), for Ya 91 , R 91 The description of R is the same as above. 92 is an oxygen atom or a sulfur atom.

[0768] Specific examples of the structural unit represented by the above formula (a9-1) or the general formula (a9-1-1) are shown below. α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0769] [Chemical formula 53]

[0770]

[0771] [Chemical formula 54]

[0772]

[0773] [Chemical formula 55]

[0774]

[0775] The structural unit (a9) contained in the component (A1) may be one kind or two or more kinds.

[0776] When the component (A1) has a structural unit (a9), the proportion of the structural unit (a9) relative to the total (100 mol%) of all the structural units constituting the component (A1) is preferably 0 to 40 mol%, more preferably 3 to 30 mol%, further preferably 5 to 25 mol%, and particularly preferably 10 to 20 mol%.

[0777] By making the proportion of the structural unit (a9) above the lower limit value, effects such as appropriately adjusting the acid diffusion length, improving the adhesion between the resist film and the substrate, appropriately adjusting the solubility during development, and improving the etching resistance can be obtained. When it is below the upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0778] Structural unit (a4): Structural unit (a4) is a structural unit containing an acid-non-dissociable aliphatic cyclic group.

[0779] The "acid non-dissociable cyclic group" in the structural unit (a4) is a cyclic group that does not dissociate even under the action of an acid and remains in the structural unit when an acid is generated in the resist composition by exposure (for example, when an acid is generated by the component (B) described later).

[0780] As the structural unit (a4), for example, a structural unit derived from an acrylate containing an acid non-dissociable aliphatic cyclic group is preferred. As the cyclic group, a large number of cyclic groups known in the art can be used as cyclic groups used as resin components of resist compositions for ArF excimer lasers, KrF excimer lasers (preferably ArF excimer lasers), etc.

[0781] In particular, at least one selected from tricyclodecanyl, adamantyl, tetracyclododecyl, isobornyl and norbornyl is preferred because of their industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

[0782] As the structural unit (a4), specifically, structural units represented by the following general formulae (a4-1) to (a4-7) can be exemplified.

[0783] [Chemical formula 56]

[0784]

[0785] [Where R α Same as above.]

[0786] The component (A1) contained in the resist composition may be used alone or in combination of two or more.

[0787] The component (A1) preferably contains a polymer compound (A1-1) having a structural unit (a1) (hereinafter also referred to as “component (A1-1)”).

[0788] Preferred components (A1-1) include, for example: polymer compounds having a repeating structure of structural units (a1) and structural units (a10); polymer compounds having a repeating structure of structural units (a1) and structural units (a3); polymer compounds having a repeating structure of structural units (a1) and structural units (a2); polymer compounds having a repeating structure of structural units (a1) and structural units (a6); and the like.

[0789] In addition to the combination of the above two structural units, the structural units described above can be appropriately combined as the third or more structural units according to the desired effect. As a combination of three or more structural units, for example, there can be mentioned: a combination of structural unit (a1) with structural unit (a10) and structural unit (a3); a combination of structural unit (a1) with structural unit (a10) and structural unit (a2); a combination of structural unit (a1) with structural unit (a10) with structural unit (a2) and structural unit (a3); a combination of structural unit (a1) with structural unit (a2) with structural unit (a3) ​​and structural unit (a6), etc.

[0790] The structural unit (a6) is preferably a structural unit (a6a) or a structural unit (a6c). When the component (A1) contains at least one of the structural unit (a6a) and the structural unit (a6c), the component (A1) is the substrate component (A) and also an onium salt.

[0791] The (A1) component can be produced by dissolving the monomers from which each structural unit is derived in a polymerization solvent, adding a free radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (such as V-601, etc.), and polymerizing. Alternatively, the (A1) component can be produced by dissolving the monomers from which the structural unit (a1) is derived, and the precursors of the monomers of the structural units other than the derived structural unit (a1) added as needed (monomers in which the functional groups of the monomers are protected) in a polymerization solvent, adding the free radical polymerization initiator mentioned above, polymerizing, and then carrying out a deprotection reaction. It should be noted that during the polymerization, the free radical polymerization initiator such as HS-CH 2 -CH 2 -CH 2 -C(CF 3 ) 2 -OH is used as a chain transfer agent to introduce -C(CF 3 ) 2-OH group. The copolymer into which a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group are replaced with fluorine atoms is introduced is effective for reducing development defects and LER (line edge roughness: uneven concavity and convexity of the line side wall).

[0792] The mass average molecular weight (Mw) of the component (A1) (based on gel permeation chromatography (GPC) and in terms of polystyrene) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000.

[0793] When the Mw of the component (A1) is below the preferred upper limit of the range, it has sufficient solubility in a resist solvent for use as a resist, and when it is above the preferred lower limit of the range, dry etching resistance and resist pattern cross-sectional shape are good.

[0794] The dispersion degree (Mw / Mn) of the component (A1) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.1 to 2.0. In addition, Mn represents a number average molecular weight.

[0795] About ingredient (A2)

[0796] The resist composition may also contain a base material component (hereinafter referred to as "component (A2)") which is not included in the above-mentioned component (A1) and whose solubility in a developer changes due to the action of an acid as the component (A).

[0797] The component (A2) is not particularly limited, and may be arbitrarily selected from a large number of substances conventionally known as base material components for chemically amplified resist compositions.

[0798] The component (A2) may be a polymer compound or a low molecular weight compound alone or in combination of two or more.

[0799] Relative to the total mass of component (A), the proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, further preferably 75% by mass or more, and may be 100% by mass. When the proportion is 25% by mass or more, it is easy to form a resist pattern with excellent lithography properties such as high sensitivity, improved resolution, and improved roughness. Such an effect is particularly significant in electron beam and EUV lithography.

[0800] In the resist composition, the content of the component (A) may be adjusted according to the thickness of the resist film to be formed, etc.

[0801] 《(B) Component》

[0802] The component (B) is an acid generator component that generates an acid by exposure.

[0803] The component (B) is not particularly limited, and any acid generator that has been proposed as an acid generator for a chemically amplified resist composition can be used.

[0804] Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, sulfonic acid oxime ester acid generators; diazomethane acid generators such as dialkyl or diarylsulfonyldiazomethanes and poly(disulfonyl)diazomethanes; and various acid generators such as nitrobenzylsulfonate acid generators, iminosulfonate acid generators, and disulfone acid generators.

[0805] Examples of the onium salt acid generator include compounds represented by the following general formula (b-1) (hereinafter also referred to as “component (b-1)”), compounds represented by general formula (b-2) (hereinafter also referred to as “component (b-2)”), and compounds represented by general formula (b-3) (hereinafter also referred to as “component (b-3)”).

[0806] [Chemical formula 57]

[0807]

[0808] [Where R 101 , R 104 ~R 108 Each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 , R 105 They may be bonded to each other to form a ring. 102 Y is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 101 is a single bond or a divalent linking group containing an oxygen atom. 101 ~V 103 Each is independently a single bond, an alkylene group or a fluoroalkylene group. 101 ~L 102 Each is independently a single bond or an oxygen atom. 103 ~L 105 Each is independently a single bond, -CO- or -SO 2 -. m is an integer greater than 1, M' m+ is an m-valent onium cation.]

[0809] {Anion part}

[0810] (b-1) Anion part of component

[0811] In formula (b-1), R 101It is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0812] The cyclic group which may have a substituent:

[0813] The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. In addition, an aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0814] R 101 The aromatic hydrocarbon group in is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. The number of carbon atoms does not include the number of carbon atoms in the substituent.

[0815] As R 101 Specifically, the aromatic ring possessed by the aromatic hydrocarbon group in the alkyl group may include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles obtained by replacing a portion of the carbon atoms constituting these aromatic rings with heteroatoms. As heteroatoms in the aromatic heterocycle, oxygen atoms, sulfur atoms, nitrogen atoms, etc. may be mentioned.

[0816] As R 101 Specifically, the aromatic hydrocarbon group in the above-mentioned group includes a group obtained by removing one hydrogen atom from the above-mentioned aromatic ring (aryl group: for example, phenyl, naphthyl, etc.), a group obtained by replacing one hydrogen atom of the above-mentioned aromatic ring with an alkylene group (for example, benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl and other arylalkyl groups, etc.). The number of carbon atoms in the above-mentioned alkylene group (alkyl chain in arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0817] R 101 The cyclic aliphatic hydrocarbon group in includes an aliphatic hydrocarbon group containing a ring in the structure.

[0818] Examples of the aliphatic hydrocarbon group containing a ring in its structure include: an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring); a group obtained by bonding an alicyclic hydrocarbon group to the terminal of a straight-chain or branched aliphatic hydrocarbon group; a group in which an alicyclic hydrocarbon group is interposed between a straight-chain or branched aliphatic hydrocarbon group, etc.

[0819] The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

[0820] The above-mentioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. As the monocycloalkane, a monocycloalkane having 3 to 6 carbon atoms is preferred, and specifically, cyclopentane, cyclohexane, etc. can be mentioned. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, a polycycloalkane having 7 to 30 carbon atoms is preferred. Among them, as the polycycloalkane, a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. is more preferred; a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton is more preferred.

[0821] Among them, as R 101 The cyclic aliphatic hydrocarbon group in is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably adamantyl and norbornyl, and most preferably adamantyl.

[0822] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

[0823] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specific examples thereof include a methylene group [—CH 2 -], ethylene [-(CH 2 ) 2 -], trimethylene [-(CH 2 ) 3 -], tetramethylene [-(CH 2 ) 4 -], pentamethylene [-(CH 2 ) 5 -]wait.

[0824] The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include -CH(CH 3 )-、-CH(CH 2 CH 3 )-、-C(CH 3 ) 2 -、-C(CH 3 )(CH 2 CH 3 )-、-C(CH 3 )(CH 2 CH 2 CH 3 )-、-C(CH 2 CH3 ) 2 -alkylmethylene; -CH(CH 3 )CH 2 -、-CH(CH 3 )CH(CH 3 )-、-C(CH 3 ) 2 CH 2 -、-CH(CH 2 CH 3 )CH 2 -、-C(CH 2 CH 3 ) 2 -CH 2 -alkylethylene; -CH(CH 3 )CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 -Alkyl trimethylene; -CH(CH 3 )CH 2 CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 CH 2 -, etc., alkyltetramethylene, etc., etc. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0825] In addition, R 101 The cyclic hydrocarbon group in may contain heteroatoms such as a heterocycle. Specifically, the cyclic groups containing lactones represented by the above-mentioned general formulae (a02-r1-1), (a02-r1-2), (a2-r-2) to (a2-r-7), the cyclic groups containing -SO 2 -cyclic group, and the heterocyclic groups represented by the above chemical formulas (R-HR-1) to (R-HR-16).

[0826] As R 101 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0827] As for the alkyl group as a substituent, an alkyl group having 1 to 12 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferred.

[0828] The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, and a tert-butoxy group, and most preferably a methoxy group and an ethoxy group.

[0829] Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.

[0830] Examples of the haloalkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, tert-butyl, etc., in which a part or all of the hydrogen atoms are substituted with the above-mentioned halogen atoms.

[0831] The carbonyl group as a substituent is a methylene group (-CH 2 -) replaced by a group.

[0832] The chain alkyl group may have a substituent:

[0833] As R 101 The chain alkyl group may be linear or branched.

[0834] The number of carbon atoms in the linear alkyl group is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. Specific examples thereof include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, and docosyl.

[0835] The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, there can be mentioned 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

[0836] The chain alkenyl group which may have a substituent:

[0837] As R 101 The chain alkenyl group may be straight-chain or branched, and the number of carbon atoms is preferably 2 to 10, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the straight-chain alkenyl group include vinyl, propenyl (allyl), butenyl, etc. Examples of the branched alkenyl group include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, 2-methylpropenyl, etc.

[0838] As the chain alkenyl group, among the above, a straight-chain alkenyl group is preferred, a vinyl group and a propenyl group are more preferred, and a vinyl group is particularly preferred.

[0839] As R 101 The substituents in the chain alkyl or alkenyl group include, for example, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, the above R 101 Cyclic groups in, etc.

[0840] Among the above, R 101 Preferably, it is a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. As the substituent, preferably a hydroxyl group, a carbonyl group, a nitro group, and an amino group, among which, from the aspect of being easily distributed on the substrate side in the resist film, a hydroxyl group is more preferred.

[0841] Specifically, the cyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; a lactone-containing cyclic group represented by each of the above general formulae (a02-r1-1), (a02-r1-2), (a2-r-2) to (a2-r-7); a -SO-containing cyclic group represented by each of the above general formulae (a5-r-1) to (a5-r-4); 2 -cyclic groups, etc.

[0842] In formula (b-1), Y 101 It is a single bond or a divalent linking group containing an oxygen atom.

[0843] Y 101 When Y is a divalent linking group containing an oxygen atom, 101 Atoms other than oxygen atoms may be contained. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.

[0844] Examples of the divalent linking group containing an oxygen atom include: a non-hydrocarbon-based linking group containing an oxygen atom, such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of the non-hydrocarbon-based linking group containing an oxygen atom and an alkylene group. The combination may further be linked to a sulfonyl group (-SO 2 -). Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulae (y-a1-1) to (y-a1-7).

[0845] [Chemical formula 58]

[0846]

[0847] [Wherein, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, V' 102 It is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0848] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and still more preferably an alkylene group having 1 to 5 carbon atoms.

[0849] As V' 101 and V' 102 The alkylene group in may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred.

[0850] As V' 101 and V' 102 Specifically, the alkylene group in the formula (a) includes: methylene [-CH 2 -]; -CH(CH 3 )-、-CH(CH 2 CH 3 )-、-C(CH 3 ) 2 -、-C(CH 3 )(CH 2 CH 3 )-、-C(CH 3 )(CH 2 CH 2 CH 3 )-、-C(CH 2 CH 3 ) 2 -Alkylmethylene; ethylene [-CH 2 CH 2 -]; -CH(CH 3 )CH 2 -、-CH(CH 3 )CH(CH 3 )-、-C(CH 3 ) 2 CH 2 -、-CH(CH 2 CH 3 )CH 2 -Alkylethylene; trimethylene (n-propylene) [-CH 2 CH 2 CH 2 -]; -CH(CH 3 )CH 2 CH 2 -、-CH 2 CH(CH 3)CH 2 -Alkyl trimethylene; tetramethylene [-CH 2 CH 2 CH 2 CH 2 -]; -CH(CH 3 )CH 2 CH 2 CH 2 -、-CH 2 CH(CH 3 )CH 2 CH 2 -Alkyl tetramethylene; pentamethylene [-CH 2 CH 2 CH 2 CH 2 CH 2 -];etc.

[0851] In addition, V' 101 or V' 102 A portion of the methylene groups in the above alkylene group may be replaced by a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably selected from Ra' in the above formula (a1-r-1): 3 It is a divalent group obtained by further removing one hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and more preferably a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

[0852] As Y 101 , preferably a divalent linking group containing an ester bond, or a divalent linking group containing an ether bond, and more preferably a linking group represented by each of the above formulae (y-al-1) to (y-al-5).

[0853] In formula (b-1), V 101 is a single bond, an alkylene group or a fluoroalkylene group. 101 The alkylene group and fluoroalkylene group in V preferably have 1 to 4 carbon atoms. 101 The fluoroalkylene group includes V 101 A group obtained by replacing some or all of the hydrogen atoms in the alkylene group with fluorine atoms. 101 It is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0854] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0855] Specific examples of the anion portion of the component (b-1) include, for example, Y 101 When Y is a single bond, examples thereof include fluoroalkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; 101 In the case of a divalent linking group containing an oxygen atom, an anion represented by any one of the following formulae (an-1) to (an-3) may be mentioned.

[0856] [Chemical formula 59]

[0857]

[0858] [Wherein, R” 101 is an aliphatic cyclic group which may have a substituent, a group represented by each of the above formulae (r-hr-1) to (r-hr-6), or a chain alkyl group which may have a substituent. R" 102 An aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group represented by each of the above general formulae (a02-r1-1), (a02-r1-2), (a2-r-2) to (a2-r-7), or a -SO-containing cyclic group represented by each of the above general formulae (a5-r-1) to (a5-r-4) 2 -cyclic group. R" 103 It is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. V" 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v" is each independently an integer of 0 to 3, q" is each independently an integer of 1 to 20, and n" is 0 or 1.]

[0859] R” 101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent is preferably the above R 101 The substituents include the cyclic aliphatic hydrocarbon groups in 101 The same groups as the substituents substituted by the cyclic aliphatic hydrocarbon groups in the above-mentioned group. Among them, hydroxyl group, carbonyl group, nitro group and amino group are preferred. Among these, hydroxyl group is more preferred because it is easily distributed on the substrate side in the resist film.

[0860] R” 103 The aromatic cyclic group which may have a substituent is preferably the above R 101 The substituents include aromatic hydrocarbon groups in the cyclic hydrocarbon groups. 101The substituents substituted by the aromatic hydrocarbon group in the above-mentioned are the same groups.

[0861] R” 101 The chain alkyl group which may have a substituent is preferably as the above R 101 The group exemplified by the chain alkyl in R” 103 The chain alkenyl group which may have a substituent is preferably as the above R 101 The group exemplified by the chain alkenyl group in .

[0862] In the above formulas (an-1) to (an-3), V" 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluoroalkylene group having 1 to 4 carbon atoms. V" 101 It is preferably a single bond, an alkylene group (methylene group) having 1 carbon atom, or a fluorinated alkylene group having 1 to 3 carbon atoms.

[0863] In the above formulas (an-1) to (an-3), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 It is preferably a perfluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom, and more preferably a fluorine atom.

[0864] In the above formulas (an-1) to (an-3), v" is an integer from 0 to 3, preferably 0 or 1. q" is an integer from 1 to 20, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2. n" is 0 or 1.

[0865] (b-2) Anion part of component

[0866] In formula (b-2), R 104 , R 105 Each is independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of them can be the same as R in formula (b-1) 101 The same group. Among them, R 104 , R 105 They may be bonded to each other to form a ring.

[0867] R 104 , R 105 It is preferably a chain alkyl group which may have a substituent, and more preferably a linear or branched alkyl group, or a linear or branched fluoroalkyl group.

[0868] The number of carbon atoms in the chain alkyl group is preferably 1 to 10, more preferably 1 to 7, and still more preferably 1 to 3. Within the above range of the number of carbon atoms, R 104 , R105 The smaller the number of carbon atoms in the chain alkyl group, the more preferred. 104 , R 105 In the chain alkyl group, the more hydrogen atoms are replaced by fluorine atoms, the stronger the acid strength becomes. In addition, the transparency to high-energy light and electron beams below 200nm is improved, so it is preferred. The ratio of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0869] In formula (b-2), V 102 、V 103 Each is independently a single bond, an alkylene group, or a fluoroalkylene group, and each of them can be the same as V in formula (b-1): 101 Same group.

[0870] In formula (b-2), L 101 , L 102 Each is independently a single bond or an oxygen atom.

[0871] (b-3) Anion part of component

[0872] In formula (b-3), R 106 ~R 108 Each is independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of them can be the same as R in formula (b-1) 101 Same group.

[0873] L 103 ~L 105 Each is independently a single bond, -CO- or -SO 2 -.

[0874] {Cationic Department}

[0875] In formula (b-1), (b-2) and (b-3), m is an integer greater than 1, and M' m+ The m-valent onium cation preferably includes a sulfonium cation and an iodonium cation, and examples thereof include organic cations represented by the above-mentioned general formulae (ca-1) to (ca-4).

[0876] [Chemical formula 60]

[0877]

[0878] [Where R 201 ~R 207 and R 211 ~R 212Each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 Each of them may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or may be bonded to each other to form a ring together with the sulfur atom in the formula. 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO-containing group which may have a substituent 2 -cyclic group. 201 represents -C(=O)- or -C(=O)-O-. Multiple Y 201 Each independently represents an arylene group, an alkylene group or an alkenylene group. x is 1 or 2. 201 represents a (x+1)-valent linking group.]

[0879] As R 201 ~R 207 and R 211 ~R 212 The aryl group in includes aryl groups having 6 to 20 carbon atoms, and preferably phenyl and naphthyl.

[0880] As R 201 ~R 207 and R 211 ~R 212 The alkyl group in the group is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

[0881] As R 201 ~R 207 and R 211 ~R 212 The alkenyl group in the is preferably an alkenyl group having 2 to 10 carbon atoms.

[0882] As R 201 ~R 207 and R 211 ~R 212 Examples of the substituent that may be possessed include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

[0883] [Chemical formula 61]

[0884]

[0885] [Wherein, R'201 Each is independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.]

[0886] Just R' 201 In addition to the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent, R 101 In addition to the same groups, examples of the cyclic group which may have a substituent or the chain alkyl group which may have a substituent include the same groups as the acid-dissociable groups represented by the above-mentioned formula (a1-r-2).

[0887] R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When they are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, carbonyl groups, -SO-, -SO 2 -、-SO 3 -, -COO-, -CONH- or -N(R N )-(The R N is an alkyl group having 1 to 5 carbon atoms. ) and the like. As the formed ring, it is preferred that the ring containing the sulfur atom in the ring skeleton is a 3-10-membered ring including the sulfur atom, and particularly preferably a 5-7-membered ring. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a thiophenethiothiol ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

[0888] R 208 ~R 209 Each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When they are alkyl groups, they may be bonded to each other to form a ring.

[0889] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO-containing group which may have a substituent 2 -cyclic group.

[0890] As R 210 The aryl group in includes unsubstituted aryl groups having 6 to 20 carbon atoms, and preferably phenyl and naphthyl.

[0891] As R 210 The alkyl group in the group is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

[0892] As R 210 The alkenyl group in the formula (R) is preferably an alkenyl group having 2 to 10 carbon atoms. 210 The -SO-containing 2 -cyclic group, preferably "containing -SO 2 -polycyclic group", more preferably a group represented by the above general formula (a5-r-1).

[0893] Y 201 Each independently represents an arylene group, an alkylene group or an alkenylene group.

[0894] Y 201 The arylene group in the formula (b-1) described below includes 101 The group obtained by removing one hydrogen atom from the aryl group exemplified as an aromatic hydrocarbon group.

[0895] Y 201 The alkylene group and alkenylene group in the formula (b-1) described below include 101 A group obtained by removing one hydrogen atom from the group exemplified by the chain alkyl group or chain alkenyl group.

[0896] In the above formula (ca-4), x is 1 or 2.

[0897] W 201 It is a (x+1)-valent, that is, a divalent or trivalent linking group.

[0898] As W 201 The divalent linking group in the formula (a2-1) is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the following: 21 Likewise, a divalent hydrocarbon group which may have a substituent. 201 The divalent linking group in can be any of linear, branched, and cyclic, preferably cyclic. Among them, preferably a group having two carbonyl groups combined at both ends of the arylene group. As the arylene group, phenylene, naphthylene, etc. can be cited, and phenylene is particularly preferred.

[0899] As W 201 The trivalent linking group in the formula (I) may be selected from the above W 201 A group obtained by removing one hydrogen atom from the divalent linking group in, a group obtained by further bonding the above divalent linking group to the above divalent linking group, etc. 201 The trivalent linking group in is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0900] Specific examples of preferred cations represented by the above formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149).

[0901] In the following chemical formula, g1 represents the number of repetitions, and g1 is an integer of 1 to 5. g2 represents the number of repetitions, and g2 is an integer of 0 to 20. g3 represents the number of repetitions, and g3 is an integer of 0 to 20.

[0902] [Chemical formula 62]

[0903]

[0904] [Chemical formula 63]

[0905]

[0906] [Chemical formula 64]

[0907]

[0908] [Chemical formula 65]

[0909]

[0910] [Chemical formula 66]

[0911]

[0912] [Chemical formula 67]

[0913]

[0914] [Chemical formula 68]

[0915]

[0916] [Chemical formula 69]

[0917]

[0918] [Chemical formula 70]

[0919]

[0920] [Chemical formula 71]

[0921]

[0922] [Wherein, R” 201 is a hydrogen atom or a substituent. As the substituent, there can be mentioned the above R 201 ~R 207 and R211 ~R 212 The substituents that may be possessed include alkyl groups, halogen atoms, halogenated alkyl groups, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by general formulae (ca-r-1) to (ca-r-7).]

[0923] Specific examples of preferred cations represented by the formula (ca-2) include cations represented by the following formulas (ca-2-1) to (ca-2-2), diphenyliodonium cations, and bis(4-tert-butylphenyl)iodonium cations.

[0924] [Chemical formula 72]

[0925]

[0926] Specific examples of preferred cations represented by the above formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-7).

[0927] [Chemical formula 73]

[0928]

[0929] Specific examples of preferred cations represented by the above formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0930] [Chemical formula 74]

[0931]

[0932] Among the above, the cationic part ((M m+ ) 1 / m ) is preferably a cation represented by the general formula (CA-1), and more preferably a cation represented by each of the chemical formulas (CA-1-1) to (CA-1-78) and (CA-1-101) to (CA-1-149).

[0933] As the onium salt-based acid generator in the present invention, the component (b-1) is particularly preferred among the components (b-1), (b-2) and (b-3).

[0934] In the resist composition, the component (B) may be used alone or in combination of two or more.

[0935] When the resist composition contains the component (B), the content of the component (B) is preferably 0 parts by mass or more, more preferably 20 to 80 parts by mass, and even more preferably 30 to 70 parts by mass, based on 100 parts by mass of the component (A).

[0936] When the content of the component (B) is within the above range, sufficient patterning can be performed.

[0937] 《(D) ingredient》

[0938] The resist composition in this embodiment may contain an alkali component (hereinafter referred to as "component (D)") in addition to component (A) or in addition to component (A) and component (B). Component (D) functions as a quencher (acid diffusion controller) that captures acid generated by exposure in the resist composition.

[0939] The component (D) may be a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes after exposure and loses its acid diffusion control property, or may be a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that is not the component (D1).

[0940] By using the resist composition containing the component (D), when forming a resist pattern, the contrast between the exposed portion and the unexposed portion of the resist film can be further improved.

[0941] About the ingredient (D1)

[0942] By preparing a resist composition containing the (D1) component, the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when forming a resist pattern. The (D1) component is not particularly limited as long as it is a substance that decomposes after exposure and loses acid diffusion control. It is preferably selected from one or more compounds in the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component")

[0943] Components (d1-1) to (d1-3) lose their acid diffusion control properties (basicity) due to decomposition in the exposed portion of the resist film and therefore do not function as a quencher, but function as a quencher in the unexposed portion of the resist film.

[0944] [Chemical formula 75]

[0945]

[0946] [Wherein, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2The carbon atoms adjacent to the S atoms in Yd are not bonded to fluorine atoms. 1 is a single bond or a divalent linking group. m is an integer greater than 1, M m+ Each is independently an m-valent organic cation.]

[0947] {(d1-1)Component}

[0948] Anion part

[0949] In formula (d1-1), Rd 1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, each of which may be the same as the above R' 201 Same group.

[0950] Among these, as Rd 1 , preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent. As substituents which these groups may have, hydroxyl, oxo, alkyl, aryl, fluorine atom, fluoroalkyl, lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof can be cited. When an ether bond or ester bond is contained as a substituent, an alkylene group may be used. As a substituent in this case, a connecting group represented by the above formulas (y-a1-1) to (y-a1-5) is preferred.

[0951] Preferred examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure formed of a bicyclooctane skeleton and other ring structures).

[0952] As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like is more preferred.

[0953] The above-mentioned chain alkyl group preferably has 1 to 10 carbon atoms. Specifically, there can be mentioned straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl; and branched-chain alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl and 4-methylpentyl.

[0954] When the above-mentioned chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, nitrogen atoms, and the like.

[0955] As Rd 1 Preferably, a fluorinated alkyl group in which a part or all of the hydrogen atoms constituting a linear alkyl group are substituted with fluorine atoms is preferred, and particularly preferably a fluorinated alkyl group in which all of the hydrogen atoms constituting a linear alkyl group are substituted with fluorine atoms (linear perfluoroalkyl group) is preferred.

[0956] Preferred specific examples of the anion part of the component (d1-1) are shown below.

[0957] [Chemical formula 76]

[0958]

[0959] ·Cationic part

[0960] In formula (d1-1), M m+ It is an m-valent organic cation.

[0961] As M m+ The organic cations may preferably be the same ions as the cations represented by the above-mentioned general formulas (CA-1) to (CA-4), more preferably the cations represented by the above-mentioned general formula (CA-1), and further preferably the cations represented by the above-mentioned formulas (CA-1-1) to (CA-1-78) and (CA-1-101) to (CA-1-149).

[0962] The component (d1-1) may be used alone or in combination of two or more.

[0963] {(d1-2)Component}

[0964] Anion part

[0965] In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the above R' 201 Same group.

[0966] Among them, Rd 2 There is no fluorine atom bonded to the carbon atom adjacent to the S atom (no fluorine substitution). As a result, the anion of the component (d1-2) becomes a moderate weak acid anion, and the quenching ability as the component (D) is improved.

[0967] As Rd 2, preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. As the chain alkyl group, preferably the number of carbon atoms is 1 to 10, more preferably 3 to 10. As the aliphatic cyclic group, more preferably a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); a group obtained by removing one or more hydrogen atoms from camphor, etc.

[0968] Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1 The substituents that the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) may have are the same as those in the above.

[0969] Preferred specific examples of the anion part of the component (d1-2) are shown below.

[0970] [Chemical formula 77]

[0971]

[0972] ·Cationic part

[0973] In formula (d1-2), M m+ is an m-valent organic cation, and M in the above formula (d1-1) m+ same.

[0974] The component (d1-2) may be used alone or in combination of two or more.

[0975] {(d1-3)Component}

[0976] Anion part

[0977] In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the above R' 201 The same group is preferably a cyclic group containing fluorine atoms, a chain alkyl group, or a chain alkenyl group. Among them, a fluorinated alkyl group is preferred, and a fluorinated alkyl group having the same structure as Rd is more preferred. 1 The same groups as the fluoroalkyl groups.

[0978] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the above R' 201 Same group.

[0979] Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent are preferred.

[0980] Rd 4 The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. 4 A part of the hydrogen atoms in the alkyl group may be substituted by a hydroxyl group, a cyano group or the like.

[0981] Rd 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and tert-butoxy. Among them, methoxy and ethoxy are preferred.

[0982] Rd 4 The alkenyl group in the above R' 201 The same groups as the alkenyl in are preferably vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0983] Rd 4 The cyclic group in the above R' 201 The same group as the cyclic group in Rd is preferably an alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or an aromatic group such as phenyl or naphthyl. 4 When it is an alicyclic group, the resist composition dissolves well in an organic solvent, thereby improving the photolithographic properties. 4 When it is an aromatic group, the resist composition is excellent in light absorption efficiency in photolithography using EUV or the like as an exposure light source, and sensitivity and photolithography characteristics become good.

[0984] In formula (d1-3), Yd 1 It is a single bond or a divalent linking group.

[0985] As Yd 1 The divalent linking group in is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. Each of these can be exemplified by the same formula as for Ya in the above formula (a2-1): 21 The same groups as those exemplified in the description of the divalent linking group in the above, the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom.

[0986] As Yd 1, preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. As the alkylene group, a linear or branched alkylene group is more preferred, and a methylene group or an ethylene group is further preferred.

[0987] Preferred specific examples of the anion part of the component (d1-3) are shown below.

[0988] [Chemical formula 78]

[0989]

[0990] [Chemical formula 79]

[0991]

[0992] ·Cationic part

[0993] In formula (d1-3), M m+ is an m-valent organic cation, and M in the above formula (d1-1) m+ same.

[0994] The component (d1-3) may be used alone or in combination of two or more.

[0995] As the component (D1), any one of the components (d1-1) to (d1-3) may be used alone, or two or more thereof may be used in combination.

[0996] When the resist composition contains the component (D1), the content of the component (D1) is preferably 0 to 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 5 to 25 parts by mass based on 100 parts by mass of the component (A).

[0997] When the content of the component (D1) is at least the lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is at most the upper limit, sensitivity can be well maintained and throughput is excellent.

[0998] (D1) Method for producing component:

[0999] The production method of the above-mentioned component (d1-1) and component (d1-2) is not particularly limited, and they can be produced by a known method.

[1000] The method for producing the component (d1-3) is not particularly limited, and the component can be produced in the same manner as described in, for example, US 2012-0149916.

[1001] About the ingredient (D2)

[1002] As the acid diffusion controller component, a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") which is not included in the above-mentioned component (D1) may be contained.

[1003] The component (D2) is not particularly limited as long as it functions as an acid diffusion controller and does not belong to the component (D1), and any known substance may be used. Among them, aliphatic amines are preferred, and aliphatic secondary amines and aliphatic tertiary amines are particularly preferred.

[1004] The aliphatic amine refers to an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.

[1005] Examples of the aliphatic amine include ammonia NH4+ with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms. 3 An amine (alkylamine or alkylolamine) or a cyclic amine obtained by replacing at least one of the hydrogen atoms of

[1006] Specific examples of alkylamines and alkylolamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkylolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[1007] Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be a monocyclic heterocyclic compound (aliphatic monocyclic amine) or a polycyclic heterocyclic compound (aliphatic polycyclic amine).

[1008] Specific examples of the aliphatic monocyclic amine include piperidine, piperazine, etc. As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferred, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[1009] Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, and triethanolamine triacetate is preferred.

[1010] Moreover, as (D2)component, an aromatic amine can be used.

[1011] Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, and derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[1012] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the content of the component (D2) is usually used in the range of 0 to 5 parts by mass relative to 100 parts by mass of the component (A). By making it within the above range, the resist pattern shape, stability over time, etc. are improved.

[1013] <<Ingredient (E): at least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxyacids and their derivatives>>

[1014] The resist composition may contain at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof (hereinafter referred to as "component (E)") as an optional component for the purpose of preventing sensitivity degradation, improving resist pattern shape, and maintaining stability over time.

[1015] As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, isophthalic acid and the like are preferred.

[1016] Examples of the phosphorus oxyacid include phosphoric acid, phosphonic acid, phosphinic acid, and the like. Among these, phosphonic acid is particularly preferred.

[1017] Examples of derivatives of phosphorus oxyacids include esters obtained by substituting hydrogen atoms of the oxyacids with hydrocarbon groups. Examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms.

[1018] Examples of the derivative of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.

[1019] Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate.

[1020] Examples of the derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

[1021] Among the above, the component (E) is preferably an organic carboxylic acid, and more preferably an aromatic carboxylic acid. Specifically, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid are preferred, and salicylic acid is more preferred.

[1022] In the resist composition, the component (E) may be used alone or in combination of two or more.

[1023] When the resist composition contains the component (E), the content of the component (E) is preferably 0 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 4 parts by mass based on 100 parts by mass of the component (A).

[1024] 《(F) ingredient: fluorine additive ingredient》

[1025] The resist composition in the present embodiment may contain a fluorine additive component (hereinafter referred to as “component (F)”) in order to impart hydrophobicity to the resist film or improve lithography characteristics.

[1026] As the component (F), for example, fluorine-containing polymer compounds described in JP-A Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used.

[1027] More specifically, the component (F) includes a polymer having a structural unit (f11) represented by the following general formula (f1-1) or a structural unit (f12) represented by the following general formula (f1-2).

[1028] The polymer having the structural unit (f11) represented by the following general formula (f1-1) is preferably a polymer (homopolymer) consisting only of the structural unit (f11) represented by the following formula (f1-1); a copolymer of the structural unit (f11) and the structural unit (a1); a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f11) is preferably a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[1029] Examples of polymers having a structural unit (f12) represented by the following general formula (f1-2) include: polymers (homopolymers) formed only from the structural unit (f12) represented by the following formula (f1-2); copolymers of the structural unit (f12) and the structural unit (a01); copolymers of the structural unit (f12) and the structural unit (a1), etc. Among them, copolymers of the structural unit (f12) and the structural unit (a01) are preferred.

[1030] [Chemical formula 80]

[1031]

[1032] [wherein, R is the same as above. Rf 102 and Rf 103 Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 Can be the same or different. 1 is an integer from 0 to 5, Rf 101 It is an organic group containing a fluorine atom. 11 ~Rf 12 Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. 13 is a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms. 14 It is a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear fluorinated alkyl group having 1 to 4 carbon atoms.]

[1033] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. R is preferably a hydrogen atom or a methyl group.

[1034] In formula (f1-1), as Rf 102 and Rf 103 Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc., and fluorine atom is particularly preferred. 102 and Rf 103 The alkyl group having 1 to 5 carbon atoms in Rf may be the same as the alkyl group having 1 to 5 carbon atoms in R, and preferably methyl or ethyl. 102 and Rf 103 The halogenated alkyl group having 1 to 5 carbon atoms may be a group in which a part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are replaced by halogen atoms. Examples of the halogen atom include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and fluorine atoms are particularly preferred. 102 and Rf 103, preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group.

[1035] In formula (f1-1), nf 1 It is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

[1036] In formula (f1-1), Rf 101 It is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.

[1037] The fluorine-atom-containing hydrocarbon group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms.

[1038] In addition, for the hydrocarbon group containing fluorine atoms, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more are fluorinated from the perspective of improving the hydrophobicity of the resist film during immersion exposure.

[1039] Among them, as Rf 101 , more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, further preferably a trifluoromethyl group, -CH 2 -CF 3 、-CH 2 -CF 2 -CF 3 、-CH(CF 3 ) 2 、-CH 2 -CH 2 -CF 3 、-CH 2 -CH 2 -CF 2 -CF 2 -CF 2 -CF 3 , especially preferably -CH 2 -CF 3 .

[1040] In formula (f1-2), R bonded to the carbon atom at the α-position is the same as described above. R is preferably a hydrogen atom or a methyl group.

[1041] In the above formula (f1-2), Rf 11 ~Rf 12 Each is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms.

[1042] R 11 ~Rf 12The alkyl group having 1 to 4 carbon atoms in the group may be linear, branched or cyclic, and is preferably a linear or branched alkyl group. Specifically, a methyl group and an ethyl group are preferred, and an ethyl group is particularly preferred.

[1043] R 11 ~Rf 12 The fluoroalkyl group having 1 to 4 carbon atoms in the alkyl group having 1 to 4 carbon atoms is a group obtained by replacing some or all of the hydrogen atoms in the alkyl group having 1 to 4 carbon atoms with fluorine atoms. In the fluoroalkyl group, the alkyl group not substituted with fluorine atoms may be linear, branched or cyclic, and examples thereof include the group similar to the above-mentioned "Rf 11 ~Rf 12 The same group as "alkyl having 1 to 4 carbon atoms".

[1044] Among the above, Rf 11 ~Rf 12 Preferably, it is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Rf is particularly preferred. 11 ~Rf 12 One of the groups is a hydrogen atom, and the other is an alkyl group having 1 to 4 carbon atoms.

[1045] In the above formula (f1-2), Rf 13 It is a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms.

[1046] R 13 The fluoroalkyl group having 1 to 4 carbon atoms in the fluoroalkyl group may be the same as the above-mentioned "Rf 11 ~Rf 12 The same group as the "fluoroalkyl group having 1 to 4 carbon atoms" is preferably a group having 1 to 3 carbon atoms, and more preferably a group having 1 to 2 carbon atoms.

[1047] R 13 The ratio of the number of fluorine atoms in the fluoroalkyl group to the total number of fluorine atoms and hydrogen atoms contained in the fluoroalkyl group (fluorination rate (%)) is preferably 30 to 100%, more preferably 50 to 100%. The higher the fluorination rate, the higher the hydrophobicity of the resist film.

[1048] Among the above, Rf 13 A fluorine atom is preferred.

[1049] In the above formula (f1-2), Rf 14 It is a linear or branched alkyl group having 1 to 4 carbon atoms, or a linear fluoroalkyl group having 1 to 4 carbon atoms, and preferably a linear alkyl group having 1 to 4 carbon atoms or a linear fluoroalkyl group having 1 to 4 carbon atoms.

[1050] As Rf 14Specific examples of the alkyl group in include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl and tert-butyl. Among them, methyl and ethyl are preferred, and methyl is most preferred.

[1051] As Rf 14 Specifically, for example, -CH 2 -CF 3 、-CH 2 -CH 2 -CF 3 、-CH 2 -CF 2 -CF 3 、-CH 2 -CF 2 -CF 2 -CF 3 As a preferred group, among them, -CH 2 -CH 2 -CF 3 .

[1052] The weight average molecular weight (Mw) of the component (F) (based on gel permeation chromatography and in terms of polystyrene) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. If it is below the upper limit of the range, when used as a resist, it has sufficient solubility in a resist solvent, and if it is above the lower limit of the range, dry etching resistance and the cross-sectional shape of the resist pattern are good.

[1053] The dispersion degree (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[1054] In the resist composition of the present embodiment, the component (F) may be used alone or in combination of two or more.

[1055] When the resist composition contains the component (F), the component (F) is usually used in an amount of 0 to 10 parts by mass based on 100 parts by mass of the component (A).

[1056] 《(S) ingredient: organic solvent ingredient》

[1057] The resist composition in the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as “component (S)”).

[1058] The component (S) may be any substance as long as it can dissolve the components used to form a uniform solution, and any substance can be appropriately selected from solvents conventionally known as solvents for chemically amplified resist compositions.

[1059] Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl n-amyl ketone, methyl isoamyl ketone, 2-heptanone, ethylene carbonate, propylene carbonate, and the like; polyols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; derivatives of the polyols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the polyols or the compounds having an ester bond; or compounds having an ether bond such as monophenyl ether. Among them, preferred are propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME)]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate and other esters; aromatic organic solvents such as anisole, ethyl benzyl ether, tolyl methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, isopropyltoluene, mesitylene, dimethyl sulfoxide (DMSO); and the like.

[1060] In the resist composition of the present embodiment, the component (S) may be used alone or as a mixed solvent of two or more.

[1061] Among the above, PGMEA, PGME, γ-butyrolactone, propylene carbonate, EL, and cyclohexanone are preferred, and PGMEA, PGME, and γ-butyrolactone are more preferred.

[1062] In addition, a mixed solvent of PGMEA and a polar solvent is also preferred. The mixing ratio (mass ratio) can be appropriately determined in consideration of the compatibility of PGMEA and the polar solvent, and is preferably set in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2.

[1063] More specifically, when EL or cyclohexanone is used as a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, and more preferably 2:8 to 8:2. In addition, when PGME is used as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. In addition, a mixed solvent of PGMEA, PGME and cyclohexanone is also preferred.

[1064] In addition, as the component (S), in addition to the above, the following mixed solvent is also preferred, wherein the mixed solvent is a mixed solvent of at least one selected from PGMEA and EL and at least one selected from γ-butyrolactone and propylene carbonate. In this case, as a mixing ratio, the mass ratio of the former to the latter is preferably 60:40 to 99:1, and more preferably 70:30 to 95:5.

[1065] In the resist composition, the content of the component (S) is 97% by mass or more relative to the total mass (100% by mass) of the resist composition. By making the content of the component (S) 97% by mass or more, pattern collapse can be suppressed, and changes in pattern dimensions before and after the above-mentioned step (i) can be suppressed. The content of the component (S) is preferably 97 to 99.95% by mass, more preferably 97 to 99.9% by mass, and further preferably 97 to 98.5% by mass.

[1066] The resist composition may further contain miscible additives as desired, such as additional resins for improving the properties of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like.

[1067] The resist composition contains the above-mentioned component (A), an onium salt, and an organic solvent component (S). The above-mentioned onium salt may be the component (A), the component (B), or the component (D).

[1068] Examples of the resist composition include: a composition comprising an onium salt-containing component (A) and an organic solvent component (S); a composition comprising an onium salt-containing component (A), an onium salt-containing component (D), and an organic solvent component (S); a composition comprising an onium salt-containing component (A), an onium salt-containing component (B), an onium salt-containing component (D), and an organic solvent component (S); a composition comprising a component (A), an onium salt-containing component (B), and an organic solvent component (S); a composition comprising a component (A), an onium salt-containing component (B), an onium salt-containing component (D), and an organic solvent component (S); etc. The resist composition preferably contains a component (E) in addition to the above components.

[1069] From the viewpoint of suppressing pattern collapse, the resist composition preferably contains two or more onium salts. Preferred examples include: a composition in which the components (A) and (D) contain onium salts; a composition in which the components (B) and (D) contain onium salts; and the like.

[1070] In the resist composition, the content of the onium salt is preferably 0.05 to 2.9 mass % relative to the total mass (100 mass %) of the resist composition. The content of the onium salt is more preferably 0.1 to 2 mass %, and further preferably 0.5 to 1.5 mass %. When the content of the onium salt is within the above range, pattern collapse can be suppressed, and changes in pattern dimensions before and after the above step (i) can be suppressed.

[1071] In addition, when the resist composition contains two or more onium salts, the content of the onium salt is the total value of the contents of all onium salts contained in the resist composition.

[1072] For example, when the resist composition contains only the component (A) as the onium salt, the content of the component (A) is preferably 0.05 to 2.9 mass%, and more preferably 0.1 to 2.8 mass%, relative to the total mass (100 mass%) of the resist composition. In addition, for example, when the resist composition contains only the component (B) as the onium salt, the content of the component (B) is preferably 0.05 to 1.6 mass%, and more preferably 0.5 to 1.4 mass%, relative to the total mass (100 mass%) of the resist composition. In addition, for example, when the resist composition contains only the component (D) as the onium salt, the content of the component (D) is preferably 0.05 to 1.6 mass%, and more preferably 0.5 to 1.0 mass% by mass%, relative to the total mass (100 mass%) of the resist composition.

[1073] In addition, for example, when the resist composition contains components (A) and (D) as onium salts, the total content of the components (A) and (D) is preferably 0.05 to 2.9% by mass relative to the total mass (100% by mass) of the resist composition. Among them, the content of the component (A) is preferably 0.04 to 2.8% by mass, and more preferably 0.5 to 2.8% by mass. In addition, the content of the component (D) is preferably 0.01 to 0.2% by mass, and more preferably 0.03 to 0.18% by mass.

[1074] In addition, for example, when the resist composition contains components (A) and (B) as onium salts, the total content of the components (A) and (B) is preferably 0.05 to 2.9% by mass relative to the total mass (100% by mass) of the resist composition. Among them, the content of the component (A) is preferably 0.04 to 2.8% by mass, and more preferably 0.5 to 2.8% by mass. In addition, the content of the component (B) is preferably 0.01 to 1.6% by mass, and more preferably 0.05 to 1.1% by mass.

[1075] In addition, for example, when the resist composition contains components (B) and (D) as onium salts, the total content of the components (B) and (D) is preferably 0.05 to 1.8% by mass relative to the total mass (100% by mass) of the resist composition. Among them, the content of the component (B) is preferably 0.04 to 1.6% by mass, and more preferably 0.08 to 1.4. In addition, the content of the component (D) is preferably 0.01 to 0.5% by mass, and more preferably 0.01 to 0.3% by mass.

[1076] In addition, for example, when the resist composition contains (A) component, (B) component and (D) component as an onium salt, the total content of the above-mentioned (A) component, the above-mentioned (B) component and the above-mentioned (D) component is preferably 0.05-2.9 mass % relative to the total mass (100 mass %) of the resist composition. Among them, as the content of the above-mentioned (A) component, it is preferably 0.04-2.8 mass %, and more preferably 0.5-2.8 mass %. In addition, as the content of the above-mentioned (B) component, it is preferably 0.01-1.6 mass %, and more preferably 0.01-1.4 mass %. In addition, as the content of the above-mentioned (D) component, it is preferably 0.01-0.5 mass %, and more preferably 0.01-0.2 mass %.

[1077] According to the manufacturing method of the purified anti-corrosion composition of the present embodiment described above, in step (i), the filtration object (anti-corrosion composition) is filtered by the following filter, wherein the filter has a porous structure in which adjacent spherical pores are connected to each other and has a porous membrane containing at least one resin skeleton selected from the group consisting of polyimide and polyamide-imide. Thus, foreign matter such as organic matter and metal impurities are removed from the filtration object at a higher level than before. In particular, by using a polyimide-based resin porous membrane, high-polarity components and polymers that were previously difficult to remove are fully removed from the filtration object, wherein high-polarity polymers are specifically removed. In addition, in step (i), metal components are also fully removed from the filtration object as impurities. In this way, by the above-mentioned manufacturing method, various foreign matter is efficiently removed to obtain a highly pure purified anti-corrosion composition.

[1078] In addition, according to the method for producing a purified product of a resist composition of the present embodiment, in step (i), a resist composition containing component (A), an onium salt, and component (S), and having a content of component (S) of 97% by mass or more, is filtered. By using such a resist composition, when a resist pattern is formed using a purified product of the resist composition after step (i) (or step (i) and step (ii)), the pattern collapse of the resist pattern is suppressed. In addition, before and after step (i) (or step (i) and step (ii)), only impurities are removed, and the composition of the resist composition changes little, so that the change of the pattern size before and after step (i) (or step (i) and step (ii))) can be suppressed.

[1079] The filter in this embodiment is not limited to a filter having a Figure 1 The filter of the porous membrane having the connecting pores 5 (which are formed by connecting the adjacent spherical chambers 1a and 1b) as shown can also have a porous membrane having the connecting pores 5 (which are formed by connecting the spherical chambers 1a and 1b) and pores or connecting pores of other shapes.

[1080] As pores of other forms (hereinafter referred to as "other pores"), pores of different shapes or pore diameters can be cited, for example, elliptical pores, polyhedral pores, spherical pores of different pore diameters, etc. As the above-mentioned "connecting holes of other forms", for example, a connecting hole formed by connecting a spherical pore with other pores can be cited.

[1081] The shapes and diameters of other cells may be appropriately determined according to the type of impurities to be removed. The communicating holes formed by the spherical cells communicating with other cells can be formed by selecting the material of the above-mentioned particles or controlling the shape of the particles.

[1082] A filter including a porous membrane having communicating holes in which adjacent spherical cells communicate with each other and cells or communicating holes of other shapes can more efficiently remove various foreign substances from a filter object.

[1083] In addition, the filter having a porous polyimide resin membrane used in the filtration process can be replaced with a filter element or the like that has been installed to remove particulate impurities in the supply pipeline of various chemical solutions or POU (point of use) in the semiconductor manufacturing process, or can also be used in combination with it. Therefore, various foreign matters can be efficiently removed from the filtered object using the same device and operation as before, and a highly pure purified resist composition can be produced.

[1084] (Method for Forming Resist Pattern)

[1085] The second embodiment of the present invention relates to a method for forming a resist pattern, comprising the following steps: a step of obtaining a purified resist composition product by using the method for producing a purified resist composition product according to the first embodiment; a step of forming a resist film on a support using the purified resist composition product; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[1086] The resist pattern forming method of this embodiment can be performed, for example, as follows: First, a purified resist composition is obtained by the method for producing a purified resist composition according to the first embodiment.

[1087] Next, the purified resist composition is applied onto a support using a spin coater or the like, and is baked (pre-baked (PAB)) at, for example, 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film.

[1088] Next, the resist film is selectively exposed using an exposure device such as an ArF exposure device, an electron beam drawing device, or an EUV exposure device, by exposing the resist film through a mask having a predetermined pattern (mask pattern) or by drawing based on direct irradiation of an electron beam without a mask pattern. The resist film is then baked (post-exposure bake (PEB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds.

[1089] Next, the resist film is subjected to a development process. The development process is performed using an alkali developer in the case of an alkali development process, or using a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[1090] After the development treatment, a rinsing treatment is preferably performed. For the rinsing treatment, in the case of an alkali development process, it is preferred to use a pure water rinse, and in the case of a solvent development process, it is preferred to use a rinsing liquid containing an organic solvent.

[1091] In the case of the solvent development process, after the development treatment or the rinsing treatment, a treatment of removing the developing solution or the rinsing solution attached to the pattern using a supercritical fluid may be performed.

[1092] After the development process or the rinsing process, drying is performed. In addition, according to circumstances, baking treatment (post-baking) may be performed after the above-mentioned development process.

[1093] In the above-described manner, a resist pattern can be formed.

[1094] The support is not particularly limited, and conventionally known supports can be used, for example, substrates for electronic components, substrates on which a predetermined wiring pattern is formed, etc. More specifically, silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, glass substrates, etc. can be used. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[1095] In addition, as a support, an inorganic and / or organic film can be provided on the above substrate. As an inorganic film, an inorganic anti-reflection film (inorganic BARC) can be cited. As an organic film, an organic anti-reflection film (organic BARC), an organic film such as a lower organic film in a multilayer resist method can be cited.

[1096] The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F 2 The purified resist composition is highly useful for use with KrF excimer laser, ArF excimer laser, EB or EUV, and is particularly useful for use with EB or EUV.

[1097] 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 lithography.

[1098] Liquid immersion exposure is an exposure method in which the space between the resist film and the lowermost lens of the exposure device is filled in advance with a solvent (liquid immersion medium) having a refractive index greater than that of air, and exposure is performed in this state (immersion exposure).

[1099] As the immersion medium, a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed is preferred. The refractive index of the solvent is not particularly limited as long as it is within the above range.

[1100] Examples of the solvent having a refractive index larger than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents.

[1101] Specific examples of fluorine-based inert liquids include C 3 HCl 2 F 5 , C 4 F 9 OCH 3 , C 4 F 9 OC 2H 5 , C 5 H 3 F 7 The liquid containing a fluorine compound as a main component is preferably a liquid having a boiling point of 70 to 180° C., and more preferably a liquid having a boiling point of 80 to 160° C. When the fluorine-based inert liquid has a boiling point within the above range, the medium used for immersion can be removed by a simple method after the exposure is completed, so it is preferred.

[1102] As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms is particularly preferred. Specific examples of the perfluoroalkyl compound include perfluoroalkyl ether compounds and perfluoroalkyl amine compounds.

[1103] In addition, specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.), and examples of the perfluoroalkylamine compound include perfluorotributylamine (boiling point 174° C.).

[1104] As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, and the like.

[1105] As an alkali developer used for the development treatment in the alkali development process, a 0.1 to 10 mass % tetramethylammonium hydroxide (TMAH) aqueous solution is mentioned, for example.

[1106] The organic solvent contained in the organic developer used for the development treatment in the solvent development process can be any solvent that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents can be cited.

[1107] Ketone solvents are organic solvents containing CC(=O)-C in their structure. Ester solvents are organic solvents containing CC(=O)-OC in their structure. Alcohol solvents are organic solvents containing alcoholic hydroxyl groups in their structure. "Alcoholic hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents containing a cyano group in their structure. Amide solvents are organic solvents containing an amide group in their structure. Ether solvents are organic solvents containing COC in their structure.

[1108] Among organic solvents, there are also organic solvents that contain multiple functional groups that give the above-mentioned solvent characteristics in their structures. In this case, they also belong to any solvent type containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether belongs to any of the alcohol solvents and ether solvents in the above classification.

[1109] The hydrocarbon solvent is composed of a halogenated hydrocarbon and is a hydrocarbon solvent having no 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 preferred.

[1110] As the organic solvent contained in the organic developer, polar solvents are preferred among those mentioned above, and ketone solvents, ester solvents, nitrile solvents and the like are preferred.

[1111] In the organic developer, known additives may be added as needed. As the additive, for example, a surfactant may be mentioned. As the surfactant, there is no particular limitation, for example, ionic, nonionic fluorine-based and / or silicon-based surfactants may be used. As the surfactant, a nonionic surfactant is preferred, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferred.

[1112] When a surfactant is added, the amount thereof is usually 0.001 to 5% by mass, pr...

Claims

1. A method for producing a purified resist composition, comprising the step (i) of filtering the resist composition using a filter having a porous structure in which adjacent spherical cells are connected to each other, The filter includes a porous membrane having at least one resin selected from the group consisting of polyimide and polyamide-imide. The resist composition comprises a base component (A) whose solubility in a developer changes due to the action of an acid, an onium salt, and an organic solvent component (S), wherein the content of the organic solvent component (S) is 97% by mass or more. The substrate component (A) comprises a polymer compound having a structural unit represented by the following general formula (a1-1) or (a1-2), In formula (a1-1) or (a1-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Va 1 is a divalent hydrocarbon group which may have an ether bond, n a1 is an integer from 0 to 2, Ra 1 is an acid dissociable group represented by the following general formula (a1-r-1) or (a1-r-2), Wa 1 n a2 +1-valent hydrocarbon group, n a2 is an integer from 1 to 3, Ra 2 is an acid-dissociable group represented by the following general formula (a1-r-1) or (a1-r-3), In formula (a1-r-1), Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group, Ra' 3 is a hydrocarbon group, and Ra' 3 Can be with Ra' 1 , Ra' 2 Any of them are bonded to form a ring, In formula (a1-r-2), Ra' 4 ~Ra' 6 Each is a hydrocarbon group, and Ra' 5 , Ra' 6 can bond to each other to form a ring, In formula (a1-r-3), Ra' 7 ~Ra' 9 Each is an alkyl group, The onium salt includes a compound represented by any one of the following general formulas (d1-1) to (d1-3), In formula (d1-1)ˉ(d1-3), Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, in, Rd in formula (d1-2) 2 The carbon atom adjacent to the S atom in the Yd 1 is a single bond or a divalent linking group, m is an integer greater than 1, M m+ Each is independently an m-valent organic cation.

2. The method for producing a purified resist composition according to claim 1, in, The content of the onium salt in the resist composition is 0.05 to 2.9 mass %.

3. The method for producing a purified resist composition according to claim 1 or 2, in, The resist composition contains two or more onium salts.

4. The method for producing a purified resist composition according to claim 1 or 2, in, The polymer compound further has a structural unit containing a hydroxystyrene skeleton.

5. The method for producing a purified resist composition according to claim 1 or 2, in, The average spherical diameter of the spherical pore chamber is 10 to 500 nm.

6. The method for producing a purified resist composition according to claim 1 or 2, in, The porous structure includes interconnected pores having an average pore diameter of 1 to 50 nm based on a BET method.

7. The method for producing a purified resist composition according to claim 1 or 2, in, The filter includes a porous polyimide membrane.

8. The method for producing a purified resist composition according to claim 1 or 2, further comprising a step (ii) of filtering the resist composition after the step (i) using a filter having a porous membrane containing a polyethylene resin.

9. A method for forming a resist pattern, comprising the steps of: A step of obtaining a purified resist composition product by using the method for producing a purified resist composition product according to any one of claims 1 to 8; A step of forming a resist film on a support using the purified product of the resist composition; a step of exposing the resist film to light; and The step of developing the exposed resist film to form a resist pattern.

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