Resist Pattern Formation Method

Abstract

A resist pattern formation method according to the present invention includes: a step for forming a resist film on a support body by using a resist composition which generates acid via light exposure and of which the solubility with an alkali developing solution is increased due to the action of the acid; a step for exposing the resist film to light; and a step for forming a positive resist pattern by alkali-developing the post-exposure resist film. Employed as the resist composition is a resist composition containing a first resin component and a second resin component, wherein the first resin component includes a polymeric compound having a constituent unit derived from acrylic acid in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the second resin component includes a polymeric compound having both a constituent unit that includes a phenolic hydroxyl group and a constituent unit that includes an acid-degradable group of which the polarity is increased by the action of acid. Through this there can be provided a novel resist pattern formation method by which development film reduction is suppressed, high sensitivity is achieved, and residue is less likely to be produced.

Description

Technical Field

[0001] The present invention relates to a method for forming a resist pattern. This application claims priority based on Japanese Patent Application No. 2020-028199 filed in Japan on February 21, 2020, and incorporates its content herein by reference.

Background Art

[0002] In lithography technology, for example, a resist film made of a resist material is formed on a substrate, selective exposure is performed on the resist film, and a development process is performed to form a resist pattern of a predetermined shape on the resist film. A resist material whose exposed portion of the resist film changes to a characteristic of being soluble in a developer is called a positive type, and a resist material whose exposed portion of the resist film changes to a characteristic of not being soluble in a developer is called a negative type. In recent years, in the manufacture of semiconductor elements, liquid crystal display elements, and electronic components, pattern miniaturization has been rapidly progressing, and photolithography is the basis for such manufacture. Photolithography is a general term for a processing technology for manufacturing various precision parts by forming a coating film on the surface of a workpiece using a photosensitive resin composition (resist composition), patterning the coating film by photolithography technology, and performing electroforming mainly including chemical etching, electrolytic etching, or electroplating using the patterned coating film as a mask.

[0003] In particular, with the downsizing of electronic devices, the high-density mounting technology of semiconductor packages has advanced, and multi-pin thin film mounting of packages, formation of fine redistribution lines, and miniaturization of package sizes have been achieved. In addition, SiP (system in package) using package technologies such as heterogeneous integration by packages, Fan-Out, TSV, 2.1D / 2.5D / 3D is also actively being studied.

[0004] To meet these requirements, resist materials are required to have lithography characteristics such as sensitivity to the exposure light source and resolution capable of reproducing patterns with fine dimensions, as well as resistance during substrate processing such as chemical etching, electrolytic etching, and wet etching using the resist as a mask, resistance to plating processes such as electrolytic and electroless plating, or characteristics adaptable to photolithography such as resistance to the lift-off process. As a resist material that meets such requirements, as a positive resist, a chemically amplified resist composition containing a base material component whose solubility in a developer changes by the action of an acid and an acid generator component that generates an acid upon exposure is used (see, for example, Patent Documents 1 and 2). For example, when the above developer is an alkaline developer (alkaline development process), as a positive chemically amplified resist composition, a resin component in which a site soluble in the alkaline developer is protected with an acid-dissociable dissolution inhibiting group (protecting group) to be hardly soluble in the developer and an acid generator component are generally used. Using the resin component to be hardly soluble in the developer is because this is greatly related to the remaining film amount in the unexposed portion. When a resist film formed using such a resist composition is selectively exposed during resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and by the action of the acid, the deprotection reaction of the pre-introduced protecting group proceeds, so that the exposed portion of the resist film becomes soluble in the alkaline developer. Therefore, by alkaline development, a positive pattern in which the unexposed portion of the resist film remains as a pattern is formed.

[0005] In such photolithography, it is necessary to form a resist pattern with a film thickness required on the surface of the support or the workpiece according to the application, etc. In the case of forming rewiring in the Fan-Out of a semiconductor package, for example, after forming a resist film with a film thickness of about 3 μm and forming a resist pattern by exposure and development through a predetermined mask pattern, plating of a conductor such as copper is performed on the non-resist portion to form a wiring portion. Alternatively, when forming bumps or metal posts on a semiconductor package, for example, a resist film with a thickness of about 60 μm is formed. After forming a resist pattern in the same way, plating of a conductor such as copper is performed on the non-resist part to form bumps or metal posts. Alternatively, in photolithography for semiconductor device processing, depending on the application or the like, a resist film with a thickness of, for example, 8 μm or more is formed on the surface of the workpiece, and a resist pattern is formed and etching or the like may be performed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] As semiconductor device processing, the diversification and high integration of semiconductor packages, etc. further evolve, deeper etching of semiconductor devices, formation of fine wiring, and further high density of protruding electrodes and metal posts are required. In response to such requirements, especially in the resist composition, a resist pattern with high sensitivity, controlled development film loss, and high resolution that can be formed without residue even with fine patterns is required. However, in the method of forming a resist pattern using a conventional chemically amplified positive resist composition, in order to suppress the dissolution of the unexposed part of the resist film by development (development film loss), it is necessary to contain, as a resist composition, a resin that is made hardly soluble in the developer by protecting the sites soluble in the developer with acid-dissociable dissolution inhibiting groups (protecting groups). Therefore, there are problems in terms of residues near the substrate interface and high sensitivity. The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist pattern forming method, which is a new method, that suppresses reduction of a developing film, has high sensitivity, and hardly generates residues.

Means for Solving the Problems

[0008] Conventionally, in a chemically amplified positive resist composition, a resin that is easily dissolved in an alkaline developer (alkaline aqueous solution) and has an acid dissociable group added thereto to make it hardly soluble in the alkaline developer has been used. In the state of a resin having an acid dissociable group, when there is a change in film thickness due to development (film reduction or swelling during development), the unexposed portion of the resist film is dissolved or swollen, and in the case of a positive resist composition, the resist pattern portion is affected. The reduction of the developing film can be expressed by the dissolution rate (nm / s). The greater the dissolution rate with respect to the alkaline developer, the greater the reduction of the unexposed portion of the resist film during development. On the other hand, the closer the dissolution rate with respect to the alkaline developer approaches zero, the smaller the reduction of the unexposed portion of the resist film during development. Further, when the dissolution rate with respect to the alkaline developer takes a negative value, it means that the resist film is swollen by the alkaline developer during development, and the greater the absolute value of the negative value, the greater the swelling amount of the resist film. Therefore, focusing on the remaining film of the resist pattern portion, it is desirable that the film reduction amount is small, so the dissolution rate with respect to the alkaline developer is preferably small. On the other hand, in a substrate having a step or the like, at a location where the exposure amount has decreased, residues after development tend to become a problem, and a margin on the low-exposure side (residue margin) is required. In particular, when focusing on the residues after development, a larger dissolution rate with respect to the alkaline developer is desirable.

[0009] In order to control the solubility in the alkaline developer to a desired value, there are known a method of controlling the introduction rate (protection rate) of an acid dissociable group (protecting group) introduced at the resin production stage, and a method of producing those having a high protection rate (having a smaller film reduction amount than a predetermined film reduction during development) and those having a low protection rate (having a larger film reduction amount than a predetermined film reduction during development), and mixing and using both so as to achieve a predetermined film reduction during development. In addition to the protection rate, a method of mixing resins with different protecting groups and monomer units themselves can also be mentioned. In particular, for residue reduction, a method of mixing a resin with a large film shrinkage amount and a different resin with a small film shrinkage amount is used. However, since the film shrinkage amount after mixing these resins takes a value between those of the respective resins used, there is a problem that it is difficult to achieve both a film shrinkage amount and a residue reduction effect.

[0010] However, the present inventors have newly found through investigations that by mixing a first resin component (P1) and a second resin component (P2), there is a combination that shows a value smaller than the dissolution rate of each individual resin in an alkaline developer (that is, it is less soluble in the alkaline developer than the first resin component (P1) and the second resin component (P2)). By selecting such a combination of resin components, it becomes possible to use the first resin component (P1), which has been difficult to form a resist due to its high dissolution rate in an alkaline developer, and by using it in combination with the second resin component (P2), a chemically amplified positive resist composition can be prepared in which the dissolution rate in the alkaline developer is smaller than that of both resins or the increase in development film shrinkage is suppressed, and it has been found that by adopting this, the above problems can be solved, leading to the completion of the present invention.

[0011] That is, one aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using a resist composition that generates an acid upon exposure and whose solubility in an alkaline developer increases by the action of the acid, exposing the resist film, and developing the exposed resist film with an alkaline developer to form a positive resist pattern. The resist composition contains a first resin component (P1) and a second resin component (P2). The first resin component (P1) includes a polymer compound (p10) having a structural unit (a0) derived from acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. The second resin component (P2) includes a polymer compound (p20) having both a structural unit (u0) containing a phenolic hydroxyl group and a structural unit (u1) containing an acid-decomposable group whose polarity increases by the action of an acid.

Advantages of the Invention

[0012] According to the present invention, a new technique is provided in which resins that are highly soluble in a developer and not hardly soluble are used alone, and by mixing the resins with each other, they can be made hardly soluble in the developer. That is, the present invention can provide a method for forming a resist pattern in which development film loss is suppressed, the sensitivity is high, and residues are less likely to occur.

Embodiments for Carrying Out the Invention

[0013] In this specification and the claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity. "Alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in an alkoxy group. "Alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Alkyl halide group" refers to a group in which some 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. "Fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of an alkyl group or an alkylene group are substituted with fluorine atoms. "Constituent unit" means a monomer unit (monomeric unit) that constitutes a high molecular compound (resin, polymer, copolymer). When described as "may have a substituent" or "may have substituents", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" is a concept that includes all irradiations of radiation.

[0014] "Base material component" is an organic compound having a film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. By the organic compound having a molecular weight of 500 or more, the film-forming ability is improved, and in addition, it becomes easy to form a nano-level resist pattern. The organic compounds used as the base material component are roughly classified into non-polymers and polymers. As the non-polymer, those having a molecular weight of usually 500 or more and less than 4000 are used. In the following, when referred to as "low molecular compound", it indicates a non-polymer having a molecular weight of 500 or more and less than 4000. As the polymer, those having a molecular weight of usually 1000 or more are used. In the following, when referred to as "resin", "high molecular compound" or "polymer", it indicates a polymer having a molecular weight of 1000 or more. The molecular weight of the polymer shall be the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography).

[0015] "Constituent unit derived from acrylate ester" means a constituent unit formed by cleavage of the ethylenic double bond of acrylate ester. "Acrylate ester" is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH2=CH-COOH) is substituted with an organic group. The hydrogen atom bonded to the α-position carbon atom of the acrylate ester may be substituted with a substituent. The substituent that substitutes the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. Further, it is assumed to include itaconic acid diesters in which "the hydrogen atom bonded to the α-position carbon atom" is substituted with a substituent containing an ester bond, and α-hydroxy acrylate esters in which "the hydrogen atom bonded to the α-position carbon atom" is substituted with a hydroxyalkyl group or a group obtained by modifying the hydroxyl group thereof. In addition, the α-position carbon atom of the acrylate ester means the carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified. Hereinafter, the acrylate ester in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as "(α-substituted) acrylate ester".

[0016] The "structural unit derived from acrylamide" means a structural unit formed by cleavage of the ethylenic double bond of acrylamide. In acrylamide, the hydrogen atom bonded to the α-position carbon atom 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. In addition, the α-position carbon atom of acrylamide means the carbon atom to which the carbonyl group of acrylamide is bonded, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom bonded to the α-position carbon atom of acrylamide include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms.

[0017] The "structural unit derived from hydroxystyrene" means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene. The "structural unit derived from a hydroxystyrene derivative" means a structural unit formed by cleavage of the ethylenic double bond of a hydroxystyrene derivative. The term "hydroxystyrene derivative" refers to a concept that includes those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of hydroxystyrene, where the hydrogen atom at the α-position may be substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the benzene ring of hydroxystyrene, where the hydrogen atom at the α-position may be substituted with a substituent, and the like. Note that the α-position (α-carbon atom) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include the same ones as those listed as the substituent at the α-position in the α-substituted acrylic acid ester.

[0018] The term "structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative" means a structural unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative. The term "vinylbenzoic acid derivative" refers to a concept that includes those in which the hydrogen atom at the α-position of vinylbenzoic acid is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the carboxyl group of vinylbenzoic acid, where the hydrogen atom at the α-position may be substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group and a carboxyl group is bonded to the benzene ring of vinylbenzoic acid, where the hydrogen atom at the α-position may be substituted with a substituent, and the like. Note that the α-position (α-carbon atom) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.

[0019] The term "styrene derivative" refers to a concept that includes those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as their derivatives. Examples of such derivatives include those in which a substituent is bonded to the benzene ring of hydroxystyrene, where the hydrogen atom at the α-position may be substituted with a substituent. Here, the α-position (α-carbon atom) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified. The terms "structural unit derived from styrene" and "structural unit derived from a styrene derivative" mean a structural unit formed by the cleavage of the ethylenic double bond of styrene or a styrene derivative.

[0020] As the alkyl group as the substituent at the α-position, a linear or branched alkyl group is preferred. Specifically, examples include alkyl groups having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group), etc. In addition, as the halogenated alkyl group as the substituent at the α-position, specifically, a group in which part or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" are substituted with halogen atoms can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferred. In addition, as the hydroxyalkyl group as the substituent at the α-position, specifically, a group in which part or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" are substituted with hydroxyl groups can be mentioned. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0021] In this specification and the claims of this patent, depending on the structure represented by the chemical formula, there may be asymmetric carbon atoms, and enantiomers or diastereomers may exist. In that case, these isomers are represented by one chemical formula. These isomers may be used alone or as a mixture.

[0022] (Method for forming a resist pattern) One aspect of the present invention is a step of forming a resist film on a support using a resist composition that generates an acid upon exposure and whose solubility in an alkaline developer increases due to the action of the acid, a step of exposing the resist film, and a step of alkali-developing the resist film after the exposure to form a positive resist pattern. In this aspect, as the resist composition, a resist composition containing a first resin component (P1) and a second resin component (P2), each having specific structural units, is employed. Details of this resist composition will be described later.

[0023] As an embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be mentioned.

[0024] [Step of forming a resist film on a support] First, a resist composition containing a first resin component (P1) and a second resin component (P2), each having specific structural units, is prepared.

[0025] Next, this resist composition is applied onto a support and heated (post-apply bake (PAB)) to form a resist film. As a method for applying the resist composition onto the support, methods such as spin coating, slit coating, roll coating, screen printing, applicator method, spray coating, inkjet method, etc. can be adopted. The conditions for the heat treatment may be appropriately determined according to the types of each component in the resist composition, the blending ratio, the coating film thickness, etc., and are, for example, 70 to 150°C, preferably 80 to 140°C, for about 1 to 60 minutes. Note that instead of directly applying the resist composition onto the support, the resist composition may be applied in advance in a film form or the like by the above coating methods, and after performing an appropriate heating step to form a film (dry film), this dry film may be attached to the support and used. The film thickness of the resist film is, for example, in the range of 1 to 250 μm, preferably 1 to 100 μm, more preferably 1 to 80 μm, and even more preferably 2 to 65 μm.

[0026] The support is not particularly limited, and a conventionally known one can be used. Examples of the support include a substrate for electronic components and a substrate with a predetermined wiring pattern formed thereon. Examples of this substrate include metal substrates such as silicon, silicon nitride, titanium, tantalum, palladium, titanium tungsten, copper, chromium, iron, aluminum, gold, etc., and glass substrates or organic material substrates laminated with metal thin films. In particular, in this embodiment, a resist pattern can be formed well on a copper substrate. Examples of the material for the wiring pattern include copper, solder, chromium, aluminum, nickel, gold, etc.

[0027] [Step of exposing the resist film] Next, the resist film formed on the support is selectively irradiated (exposed) with radiation including electromagnetic waves or particle beams, such as ultraviolet rays or visible light with a wavelength of 240 to 500 nm, through a mask with a predetermined pattern or using an apparatus capable of direct drawing without using a mask.

[0028] As the radiation source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, an excimer laser, a light-emitting diode (LED), etc. can be used. Also, radiation includes microwaves, infrared rays, visible light, ultraviolet rays, X-rays, γ-rays, electron beams, proton beams, neutron beams, ion beams, etc. The irradiation amount of the radiation may be appropriately determined according to the types, blending amounts of the respective components in the resist composition, the film thickness of the coating film, etc. Also, the radiation includes light rays for activating an acid generator to generate an acid.

[0029] Next, after exposing the resist film, preferably, by heating (post-exposure bake (PEB)) using a known method, the diffusion of acid and the deprotection of acid dissociable groups (protecting groups) are promoted to change the alkali solubility of the exposed portion of the resist film. The conditions for the heat treatment here may be appropriately determined according to the types of each component in the resist composition, the blending ratio, the coating film thickness, etc. For example, 80 to 150 °C is preferable and it is about 1 to 60 minutes.

[0030] [Step of alkali-developing the resist film after exposure] Next, for example, using an alkaline aqueous solution as a developer, unnecessary portions are dissolved and removed to obtain a predetermined positive resist pattern.

[0031] As the developer, for example, aqueous solutions of alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonane can be used. The concentration of alkalis in the developer may be appropriately set according to the type of resin, etc. For example, in the case of a TMAH aqueous solution, 0.75 to 5 mass% is preferable and 2 to 3 mass% is more preferable.

[0032] Also, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the aqueous solution of the alkalis can also be used as the developer. The concentration of the surfactant in the developer is preferably, for example, 0.02 to 2.5 mass%.

[0033] The alkali development time may be appropriately determined according to the types of each component of the resist composition, the blending ratio, and the dry film thickness of the composition, and is preferably 0.5 to 30 minutes. Also, the alkali development method may be any of a liquid filling method, a dipping method, a paddle method, a spray development method, etc. After alkali development, if necessary, running water washing may be performed for, for example, 30 to 90 seconds, and drying may be performed using a spin drying method, an air gun, an oven, or the like.

[0034] By embedding a conductor such as a metal, for example, by plating, etc. in the non-resist portion (the portion removed by the alkali developer) of the resist pattern obtained as described above, conductive structures such as wirings, metal posts, and bumps can be formed. In addition, the plating treatment method is not particularly limited, and various conventionally known methods can be adopted. As the plating solution, in particular, a solder plating, a copper plating, a gold plating, or a nickel plating solution is preferably used. The remaining resist pattern is finally removed using a stripping solution or the like according to a conventional method. Alternatively, substrate processing such as chemical etching, electrolytic etching, and wet etching using the resist pattern obtained as described above as a mask can be performed.

[0035] <Resist composition> The resist composition used in the resist pattern forming method of the present embodiment generates an acid upon exposure, and its solubility in an alkali developer increases due to the action of the acid. Such a resist composition contains a resin component (P) (hereinafter also referred to as the "(P) component") whose solubility in a developer increases due to the action of an acid. Examples of the resist composition in the present embodiment include those containing the (P) component and an acid generator component (hereinafter also referred to as the "(B) component") that generates an acid upon exposure.

[0036] When a resist film is formed using such a resist composition and selective exposure is performed on the resist film, acid is generated in the exposed portion of the resist film, and the solubility of the resin component in the developer changes due to the action of the acid. On the other hand, in the unexposed portion of the resist film, the solubility of the resin component 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, in the present embodiment, when the resist film is developed with an alkali, the exposed portion of the resist film is dissolved and removed, and a positive resist pattern is formed.

[0037] ≪(P) Component: Resin Component≫ In the present embodiment, the resin component (P) ((P) component) includes at least a first resin component (P1) (hereinafter also referred to as “(P1) component”) and a second resin component (P2) (hereinafter also referred to as “(P2) component”).

[0038] Regarding the first resin component (P1): In the present embodiment, the first resin component (P1) ((P1) component) includes a polymer compound (p10) (hereinafter also referred to as “(p10) component”) having a structural unit (a0) derived from acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. The (p10) component may have other structural units as necessary in addition to the structural unit (a0).

[0039] · Structural unit (a0) The structural unit (a0) is a structural unit derived from acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. The “structural unit derived from acrylic acid” means a structural unit formed by cleavage of the ethylenic double bond of acrylic acid. The acrylic acid referred to herein may have the hydrogen atom bonded to the α-carbon atom substituted with a substituent. The substituent that substitutes the hydrogen atom bonded to the α-carbon atom is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and the like. Note that the α-carbon atom in acrylic acid refers to the carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.

[0040] Preferable specific examples of such a structural unit (a0) include a structural unit represented by the following general formula (a0-0).

[0041] [Chemical formula] [In the formula, R 0 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.]

[0042] In the above formula (a0-0), R 0 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R 0 The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. R 0 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 from the viewpoint of easy industrial availability, a hydrogen atom or a methyl group is particularly preferable, that is, it is preferably acrylic acid or methacrylic acid.

[0043] (p10) The constituent unit (a0) that the component has may be one type or two or more types. (p10) The proportion of the constituent unit (a0) in the component is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, and even more preferably 10 to 25 mol% with respect to the total (100 mol%) of all the constituent units constituting the (p10) component. By setting the proportion of the constituent unit (a0) to be not less than the lower limit value, characteristics such as sensitivity and residue reduction are improved. Also, by setting it to be not more than the upper limit value, a balance with other constituent units can be achieved.

[0044] ·Regarding other constituent units: Such a (p10) component may have other constituent units in addition to the constituent unit (a0), if necessary. Examples of other constituent units include a constituent unit (a1) derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent and which contains an acid-decomposable group whose polarity increases by the action of an acid; and a constituent unit (a2) derived from a polymerizable compound having an ether bond.

[0045] ··Constituent unit (a1) The constituent unit (a1) is a constituent unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent and which contains an acid-decomposable group whose polarity increases by the action of an acid and whose solubility in an alkaline developer is improved. The "acid-decomposable group" is a group having acid-decomposability 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. Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a sulfo group (-SO3H), etc. Among these, a carboxy group is preferred. More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of a carboxy group is protected by an acid-dissociable group). Here, the "acid dissociable group" refers to both (i) a group having acid dissociability such that the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved by the action of an acid, or (ii) a group having acid dissociability such that the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved by decarboxylation reaction after some bonds are cleaved by the action of an acid.

[0046] The acid dissociable group is not particularly limited, and those proposed as the acid dissociable group of the base resin for chemically amplified resists can be used.

[0047] Among the above polar groups, examples of the acid dissociable group for protecting the carboxy 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"), and an acid dissociable group represented by the following general formula (a1-r-2) (among the acid dissociable groups represented by the general formula (a1-r-2), those composed of an alkyl group are hereinafter sometimes referred to as "tertiary alkyl ester type acid dissociable groups" for convenience).

[0048] [Chemical formula] [In the formula, Ra’ 1 , Ra’ 2 is a hydrogen atom or an alkyl group, Ra’ 3 is a hydrocarbon group, and Ra’ 3 may combine with either Ra’ 1 , Ra’ 2 to form a ring.]

[0049] Regarding the acid dissociable group represented by the general formula (a1-r-1): In the formula (a1-r-1), it is preferable that at least one of Ra’ 1 and Ra’ 2 is a hydrogen atom, and more preferably both are hydrogen atoms. Ra’ 1 or Ra’ 2When it is an alkyl group, examples of the alkyl group include the same ones as the alkyl groups listed as substituents that may be bonded to the carbon atom at the α-position in the description of the above α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are included, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred.

[0050] In formula (a1-r-1), Ra’ 3 Examples of the hydrocarbon group of include linear, branched or cyclic alkyl groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. are included. Among these, a methyl group, an ethyl group or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred. The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specifically, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, etc. are included, and an isopropyl group is most preferred. The cyclic alkyl group preferably has 3 to 20 carbon atoms, more preferably 4 to 12. Specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are included. A part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with an etheric oxygen atom (-O-).

[0051] Ra’ 3 is Ra’ 1 , Ra’ 2When combined with any of them to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

[0052]

Chemical formula

[0053] Regarding the acid dissociable group represented by the general formula (a1-r-2): In the formula (a1-r-2), the hydrocarbon groups of Ra’ 4 ~Ra’ 6 are the same as those of the aforementioned Ra’ 3 . Ra’ 4 is preferably an alkyl group having 1 to 5 carbon atoms. When Ra’ 5 and Ra’ 6 are bonded to each other to form a ring, a group represented by the following general formula (a1-r2-1) can be mentioned. On the other hand, when Ra’ 4 ~Ra’ 6 are not bonded to each other and are independent hydrocarbon groups, a group represented by the following general formula (a1-r2-2) can be mentioned.

[0054]

Chemical formula

[0055] In the formula (a1-r2-1), Ra’ 10The alkyl group having 1 to 10 carbon atoms in 3 is preferably a group exemplified as the linear or branched alkyl group of Ra’ in the formula (a1-r-1). In the formula (a1-r2-1), Ra’ 11 The aliphatic cyclic group formed by 3 is preferably a group exemplified as the cyclic alkyl group of Ra’ in the formula (a1-r-1).

[0056] In the formula (a1-r2-2), Ra’ 12 and Ra’ 14 are each preferably an alkyl group having 1 to 10 carbon atoms, and the alkyl group is more preferably a group exemplified as the linear or branched alkyl group of Ra’ in the formula (a1-r-1), still more preferably a linear alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. 3 In the formula (a1-r2-2), Ra’ is preferably a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group of Ra’ in the formula (a1-r-1). Among these, it is more preferably a group exemplified as the cyclic alkyl group of Ra’ 13 In the formula (a1-r2-2), Ra’ 3 is preferably a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group of Ra’ in the formula (a1-r-1). Among these, it is more preferably a group exemplified as the cyclic alkyl group of Ra’ 3 The following are specific examples of the formula (a1-r2-1).

[0057] The following are specific examples of the formula (a1-r2-2).

[0058]

Chemical formula

[0059] Preferred specific examples of such a structural unit (a1) include a structural unit represented by the following general formula (a1-1).

[0060]

Chemical formula

[0061] Preferred specific examples of such a structural unit (a1) include a structural unit represented by the following general formula (a1-1).

[0062]

Chemical formula

[0063] In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably linear or branched, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. can be mentioned. The alkyl halide group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable. Va 1 The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in its structure. Also, Va 1 includes those in which the above divalent hydrocarbon group is bonded via an ether bond, a urethane bond, or an amide bond.

[0064] The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0065] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The linear or branched aliphatic hydrocarbon group is the same as the linear or branched aliphatic hydrocarbon group exemplified in the description of the divalent hydrocarbon group in Va 1 and is the same as those exemplified in the description of the linear or branched aliphatic hydrocarbon group as the divalent hydrocarbon group in Va. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

[0066] The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The above Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in is preferably 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom; and the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group), where one hydrogen atom of the aryl group is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); and the like. The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably from 1 to 4, more preferably from 1 to 2, and particularly preferably 1.

[0067] In the formula (a1-1), Ra 1 is preferably an acid dissociable group represented by the above formula (a1-r-2).

[0068] Specific examples of the formula (a1-1) are shown below. In the following formulas, R α is a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0069]

Chemical formula

[0070]

Chemical formula

[0071]

Chemical formula

[0072] (p10) The constitutional unit (a1) possessed by the component may be one kind or two or more kinds. (p10) When the component has a constitutional unit (a1), the proportion of the constitutional unit (a1) in the (p10) component is preferably 5 to 95 mol%, more preferably 10 to 80 mol%, still more preferably 15 to 60 mol% with respect to the total of all constitutional units (100 mol%) constituting the (p10) component. By setting the proportion of the constitutional unit (a1) to be equal to or higher than the lower limit value, a resist pattern can be easily obtained and characteristics such as resolution are improved. Further, by setting it to be equal to or lower than the upper limit value, a balance with other constitutional units can be achieved.

[0073] ··Constitutional unit (a2) The constitutional unit (a2) is a constitutional unit derived from a polymerizable compound having an ether bond. Examples of the polymerizable compound having an ether bond include radical polymerizable compounds such as (meth)acrylic acid derivatives having an ether bond and an ester bond. Specific examples include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and the like. Further, the polymerizable compound having an ether bond is preferably 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, or methoxytriethylene glycol (meth)acrylate. These polymerizable compounds may be used alone or in combination of two or more.

[0074] Such a (p10) component may further include a constitutional unit derived from another polymerizable compound for the purpose of appropriately controlling physical or chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds. Examples of such polymerizable compounds include, for example, monocarboxylic acids such as crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; diesters of dicarboxylic acids such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; and the like.

[0075] Such (p10) component may further have a structural unit (a4) containing an acid non-dissociable cyclic group, if necessary. It is considered that when the (p10) component has the structural unit (a4), the dry etching resistance, heat resistance, or plating resistance of the formed resist pattern is improved. The "acid non-dissociable cyclic group" in the structural unit (a4) is a cyclic group that remains as it is in the structural unit without dissociating even when the acid generated by exposure acts on it. As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group is preferable. As the cyclic group, a number of those conventionally known for use in the resin component of the resist composition can be used. In particular, it is preferable in terms of easy availability in industry that it is at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include those having any of the structures represented by the following general formulas (a4-1) to (a4-7).

[0076] [Chemical formula] [In the formula, R α is the same as described above.]

[0077] The structural unit (a4) contained in the (p10) component may be one kind or two or more kinds.

[0078] The (P1) component used in the resist composition in this embodiment contains a polymer compound (p10) having a structural unit (a0). As the (p10) component, preferably, a polymer compound having a structural unit (a0) and a structural unit (a1); a polymer compound having a structural unit (a0) and a structural unit (a2); a polymer compound having a structural unit (a0) and a structural unit derived from a (meth)acrylic acid alkyl ester. More preferably, as the (p10) component, a polymer compound having a structural unit (a0), a structural unit (a1), a structural unit (a2), and a structural unit derived from a (meth)acrylic acid alkyl ester; a polymer compound having a structural unit (a0), a structural unit (a2), and a structural unit derived from a (meth)acrylic acid alkyl ester can be mentioned.

[0079] (P10) The weight average molecular weight (Mw) of the component (in terms of polystyrene equivalent by gel permeation chromatography (GPC)) is not particularly limited, preferably from 5,000 to 500,000, more preferably from 10,000 to 400,000, and even more preferably from 20,000 to 300,000. (P10) When the Mw of the component is below the preferable upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is above the preferable lower limit of this range, it has good dry etching resistance and plating resistance. (P10) The dispersity (Mw / Mn) of the component is not particularly limited, preferably from 1.0 to 20.0, more preferably from 1.0 to 15.0, and particularly preferably from 1.1 to 13.5. Here, Mn represents the number average molecular weight.

[0080] Regarding the second resin component (P2): In this embodiment, the second resin component (P2) ((P2) component) includes a polymer compound (p20) (hereinafter also referred to as "(p20) component") having a structural unit (u0) containing a phenolic hydroxyl group and a structural unit (u1) containing an acid-decomposable group whose polarity increases by the action of an acid. (P20) component may have other structural units as necessary in addition to the said structural unit (u0) and the said structural unit (u1).

[0081] · Structural unit (u0) The structural unit (u0) is a structural unit containing a phenolic hydroxyl group. Preferable specific examples of the structural unit (u0) include a structural unit represented by the following general formula (u0-0).

[0082] [Chemical formula] [In the formula, R 22 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 22 is a divalent linking group or a single bond. Wa 22 is an (n a22 +1)-valent aromatic hydrocarbon group. na22 is an integer from 1 to 3.]

[0083] In the formula (u0-0), R 22 The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. can be mentioned. R 22 The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc., and fluorine atom is particularly preferable. R 22 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. From the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0084] In the formula (u0-0), Va 22 As the divalent linking group in, for example, a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom are mentioned as suitable ones.

[0085] · The divalent hydrocarbon group which may have a substituent: Va 22 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0086] ·· Va 22 The aliphatic hydrocarbon group in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in the structure.

[0087] ···a linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. can be mentioned. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, etc. can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0088] The above-mentioned linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, etc.

[0089] ···an aliphatic hydrocarbon group containing a ring in the structure 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 hetero atom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon groups exemplified in the description of the aliphatic hydrocarbon group in 22 Va. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. 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 preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0090] 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, a carbonyl group, and the like. The alkyl group as the substituent preferably has 1 to 5 carbon atoms, and most preferably is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent preferably has 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0091] ··Va 22 The aromatic hydrocarbon group in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms, etc. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the 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 (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0092] In the aromatic hydrocarbon group, the hydrogen atoms of the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0093] · Divalent linking group containing a heteroatom: Va 22 When Va is a divalent linking group containing a heteroatom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 -or -Y 21 -S(=O)2-O-Y 22 -represented groups [wherein, Y 21 and Y 22 are each 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. are exemplified. When the divalent linking group containing the hetero atom is -C(=O)-NH-,-C(=O)-NH-C(=O)-,-NH-,-NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 -or -Y 21 -S(=O)2-O-Y 22 -Among them, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group are the same as those (divalent hydrocarbon groups which may have a substituent) mentioned in the description of the divalent linking group. Y 21As for this, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. Y 22 As for this, a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. In the formula -[Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, 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, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As the group represented by -, the group represented by the formula -Y 21 -C(=O)-O-Y 22 - is particularly preferable. Among them, the group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - is preferable. 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, still more 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, still more preferably 1 or 2, and most preferably 1.

[0094] Va 22 As for this, 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 is preferable, and among them, a single bond is particularly more preferable.

[0095] In the formula (u0-0), the aromatic hydrocarbon group in Wa 22 is, from the aromatic ring (n a22Examples of the group excluding one hydrogen atom are given below. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and it may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0096] In the formula (u0-0), n a22 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.

[0097] Specific examples of the structural unit (u0) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0098]

Chemical formula

[0099] The structural unit (u0) contained in the (p20) component may be one kind or two or more kinds. In the (p20) component, the proportion of the structural unit (u0) is preferably, for example, 40 to 90 mol%, more preferably 50 to 85 mol%, and particularly preferably 60 to 80 mol% with respect to the total (100 mol%) of all the structural units constituting the (p20) component. By setting the proportion of the structural unit (u0) within the above-mentioned preferred range, characteristics such as sensitivity and residue reduction are improved.

[0100] · Structural unit (u1) The structural unit (u1) is a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid. The "acid-decomposable group" referred to here is, like the acid-decomposable group in the above structural unit (a1), a group having acid-decomposability 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. Examples of the acid-decomposable group whose polarity increases by the action of an acid include groups that decompose by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a sulfo group (-SO3H), etc. Among these, a carboxy group is preferable. More specifically, examples of the acid-decomposable group include a group in which the above polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of a carboxy group is protected by an acid-dissociable group).

[0101] The acid-dissociable group is not particularly limited, and those proposed as the acid-dissociable group of the base resin for chemically amplified resists can be used.

[0102] Among the above polar groups, examples of the acid-dissociable group that protects a carboxy group include, for example, the acid-dissociable group represented by the above general formula (a1-r-1) (acetal-type acid-dissociable group), and the acid-dissociable group represented by the above general formula (a1-r-2) (among the acid-dissociable groups represented by the general formula (a1-r-2), those composed of an alkyl group: tertiary alkyl ester-type acid-dissociable group).

[0103] Preferable specific examples of the structural unit (u1) include a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and containing an acid-decomposable group whose polarity increases by the action of an acid. Examples of the structural unit (u1) include the same ones as the above structural unit (a1). Among them, the structural unit represented by the above general formula (a1-1) is preferably mentioned, and Ra in the formula (a1-1) 1 is more preferably an acid-dissociable group represented by the above formula (a1-r-2), and even more preferably an acid-dissociable group represented by the above formula (a1-r2-2). In the above formula (a1-r2-2), Ra’ 12 , Ra’ 13 and Ra’ 14 are each independently preferably an alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

[0104] Alternatively, preferred specific examples of the structural unit (u1) include a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group. For example, there may be mentioned a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene is protected by an ethoxyethyl group. Further, there may be mentioned a structural unit in which at least a part of the hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene is protected by a tertiary alkyloxycarbonyl (t-Boc) group.

[0105] The structural unit (u1) contained in the component (p20) may be one kind or two or more kinds. In the component (p20), the proportion of the structural unit (u1) is preferably, for example, 5 to 50 mol%, more preferably 10 to 45 mol%, and particularly preferably 15 to 40 mol% with respect to the total (100 mol%) of all the structural units constituting the component (p20). By setting the proportion of the structural unit (u1) within the above-mentioned preferred range, characteristics such as sensitivity and residue reduction are improved.

[0106] In addition to the structural unit (u0) and the structural unit (u1), the component (p20) may have other structural units derived from a polymerizable compound such as styrene. Examples of such a polymerizable compound include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, α-methylstyrene; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate.

[0107] (p20) The weight average molecular weight of the component is preferably 1,000 to 50,000.

[0108] Further, in the resist composition of the present embodiment, the dissolution rate of the (P1) component in the alkaline developer is DR P1 , the dissolution rate of the (P2) component in the alkaline developer is DR P2 , and the dissolution rate of the mixed resin of the (P1) component and the (P2) component in the alkaline developer is DR MIX When this is the case, it is preferable to use the (P1) component and the (P2) component in combination such that there exists a mixing ratio where DR MIX < DR P1 , and also DR MIX < DR P2 . That is, it is preferable to select a combination of resins in which the dissolution rate of the mixed resin in the alkaline developer is lower than the dissolution rates of the individual resins in the alkaline developer. By doing so, during resist pattern formation, even for a resin that was difficult to use because of its high dissolution rate in the alkaline developer, reduction of the developed film is suppressed and residues are less likely to occur. That is, it is preferable to select a combination of resins in which the dissolution rate of the mixed resin in the alkaline developer is lower than the dissolution rates of the individual resins in the alkaline developer. By doing so, during resist pattern formation, even for a resin that was difficult to use because of its high dissolution rate in the alkaline developer, reduction of the developed film is suppressed and residues are less likely to occur.

[0109] Conventionally, as the resin component (P), a resin in which an acid dissociable group is introduced into a resin that easily dissolves in an alkaline developer (alkaline aqueous solution) to make it hardly soluble in the alkaline developer has been used. To control the dissolution rate in the alkaline developer to a desired value and make it hardly soluble in the alkaline developer, there are a method of controlling the introduction rate (protection rate) of the acid dissociable group (protecting group) introduced into the alkali-soluble resin at the resin production stage, and a method of considering variations during production, for example, manufacturing resins with different protection rates and mixing them to obtain a hardly soluble resin (mixed resin) having a desired dissolution rate. In this case, the hardly soluble resin P' MIX (dissolution rate DR' MIX ), the resin P' H with a high protection rate and a slow dissolution rate before mixing (dissolution rate DR' PH ), and the resin P' L with a low protection rate and a fast dissolution rate before mixing (dissolution rate DR'PL ) and the relationship between the dissolution rate with respect to the alkaline developer is DR’ PH <DR’ MIX <DR’ PL and it was generally the case. In addition to the protection rate, there may be cases where resins having different protecting groups and monomer units themselves are mixed. Even in this case, resin P with a large film reduction amount X (dissolution rate DR Px ) and a different resin P with a small film reduction amount Y (dissolution rate DR PY ) are mixed to form resin P” MIX (dissolution rate is DR” MIX ) is known, but the relationship between the dissolution rates with respect to the alkaline developer after mixing is DR PY <DR” MIX <DR Px and it was generally the case.

[0110] However, in this embodiment, as described above, a resist composition having both a (P1) component and a (P2) component that satisfies a specific dissolution rate relationship (that is, DR MIX <DR P1 , and DR MIX <DR P2 ) is preferably employed (even when using a resin having a relatively high dissolution rate with respect to the alkaline developer, the dissolution rate of the mixed resin is relatively suppressed). As a result, at the time of forming a resist pattern, a resist pattern with higher sensitivity and controlled development film reduction can be formed, and a resist pattern with high resolution capable of forming a fine pattern without residue can be formed even on a stepped substrate.

[0111] [Dissolution rate of resin with respect to alkaline developer] The dissolution rate (DR) of the resin with respect to the alkaline developer varies greatly depending on the type, concentration, and temperature of the alkaline developer used. Therefore, in the present invention, the dissolution rate measured and calculated under the developer and development conditions to be used or planned to be used for resist patterning as the final resist composition is defined. The dissolution rate (DR) of the resin in an alkaline developer varies depending on factors such as the film thickness of the coating film and the heating conditions, although not as much as with the developer. Ideally, the dissolution rate should be defined as the rate calculated when a resin film is prepared under the conditions actually used, that is, the film thickness of the coating film used or planned to be used for resist patterning as a resist composition and the heating conditions (PAB) during coating, and then developed with the aforementioned developer under the development conditions. However, the film thickness of the coating film and the heating conditions during coating are changed as appropriate depending on the purpose. Therefore, in the present invention, the dissolution rate obtained and calculated by the method shown in the following measurement procedure is defined as the "dissolution rate of the resin in an alkaline developer".

[0112] The measurement of the "dissolution rate of the resin in an alkaline developer" defined in the present invention shall conform to the following procedures (1) to (6) or procedures (1') to (6').

[0113] Procedure (1): Mix the resin with the organic solvent component (solvent) usually used in the resist composition to prepare a resin solution. The resin solution may be prepared by mixing a pre-mixed plurality of resins with the organic solvent component, or by preparing resin solutions of individual resins and then mixing them in the required proportions. If necessary, dilution with a solvent or addition of an appropriate amount of a leveling agent (surfactant) may be performed. Procedure (2): After applying the resin solution to a silicon wafer, perform a baking treatment (PAB) at 120°C for 90 seconds to form a resin film with a thickness of about 4 μm. Procedure (3): Measure the film thickness (initial film thickness X) of the resin film. Procedure (4): Without subjecting the silicon wafer on which the resin film is formed to exposure and the post-exposure heat treatment process (PEB), develop it with a predetermined alkaline developer at a predetermined temperature for 60 seconds using a developing machine, and then perform water washing and drying (non-heating drying such as spin drying or N2 air blowing). Procedure (5): After development, measure the film thickness (post-development film thickness Y) of the resin film. Procedure (6): Calculate the dissolution rate (DR) of the resin in the alkaline developer. DR (nm / s) = (X - Y) / 60 seconds (development time)

[0114] In the above procedure, if the resin film is completely dissolved during development, the development time in step (4) may be shortened to 30 seconds for measurement. Also, when it is difficult to use a silicon wafer or a developer, or when measurement is difficult with the above procedure, measurement shall be performed according to the following steps (1') to (6').

[0115] Step (1'): Prepare a resin solution by mixing the resin with the organic solvent component (solvent) normally used in the resist composition. For preparing the resin solution, a mixture of a plurality of resins previously mixed may be mixed with the organic solvent component, or resin solutions of individual resins may be prepared first and then mixed at a required ratio. If necessary, dilution with a solvent or addition of an appropriate amount of a leveling agent (surfactant) may be performed. Step (2'): After applying the resin solution onto a support capable of measuring film thickness such as on a silicon wafer, perform a baking treatment (PAB) at 120°C for 120 seconds to form a resin film with a thickness of about 4 μm. Step (3'): Measure the film thickness (initial film thickness X) of the resin film. Step (4'): Place a predetermined alkaline developer in a container such as a beaker or a vat. The developer may be temperature-controlled as necessary to set the developer to a predetermined temperature. Note that the size of the container should be selected such that the support on which the resin film was formed in step (2') can fit, or the support on which the resin film was formed should be cut to a size that can fit into the container. Step (5'): Immerse the support in the alkaline developer in the container and measure the time (dissolution time Z) until the formed resin film is completely dissolved. Note that the dissolution time is limited to 2 minutes. If it is not completely dissolved after 2 minutes, take out the support, appropriately perform water washing and drying, and measure the film thickness of the resin (film thickness after development Y). Step (6'): Calculate the dissolution rate (DR) of the resin in the alkaline developer. When completely dissolved: DR (nm / s) = (X) / (Z) When not completely dissolved: DR (nm / s) = (X - Y) / 120 seconds (development time)

[0116] Note that the DR shown in this embodiment P1 , DRP2 、 DR MIX For the purpose of comparing the magnitudes of DR, even without using the measurement under the developer, development conditions, resin film thickness, and production conditions used or planned to be used during resist patterning as the final resist composition, it is also possible to examine the values regarding the dissolution rate values obtained by comparison under the same developer, development conditions, resin film thickness, and resin film production conditions. Specifically, as an example, when using a 2.38 mass% TMAH developer and development conditions of 23 °C for the final resist patterning, in the measurement and comparison of the dissolution rate, DR is calculated using 5 mass% TMAH in the developer, and DR P1 、 DR P2 、 DR MIX The magnitude comparison of may also be performed. This method of using 5 mass% TMAH in the developer is particularly an effective method for comparative study in the case where DR takes a small value under the developer and development conditions used or planned to be used during resist patterning as the final resist composition. Similarly, if DR can be measured under the same conditions even when changing the thickness and film formation conditions of the resin film, comparison can be made with the observed values. P2 If DR

[0117] Also, even for measurement methods other than the above procedures, as long as the dissolution rate capable of comparing the magnitudes of DR shown in this embodiment can be measured, for example, as an example, the dissolution rate may be obtained and compared by the quartz crystal microbalance (QCM) method or the like. P1 、 DR P2 、 DR MIX This is because although the DR values observed vary depending on the measurement conditions and methods, the relative positional relationship of the values observed under the same conditions does not change. In the resist composition used in the resist pattern forming method of this embodiment, the (P) component may contain a resin component other than the (P1) component and the (P2) component (hereinafter this resin component is also referred to as the "(P3) component").

[0118] ​(P3) The components are not particularly limited, and examples include novolac-type phenol resins (p31), polyhydroxystyrene-based resins (p32) (excluding those corresponding to the (P2) component), etc.

[0119] Novolac-type phenol resin (p31): As the novolac-type phenol resin (p31) ((p31) component), for example, those obtained by addition condensation of an aromatic compound having a phenolic hydroxyl group (phenols) and aldehydes under an acid catalyst can be used.

[0120] Examples of the above phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, phloroglucinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid ester, α-naphthol, β-naphthol, etc. Examples of the above aldehydes include formaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, acetaldehyde, etc. The acid catalyst in the addition condensation reaction is not particularly limited, and for example, hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, etc. are used.

[0121] Among the above, the (p31) component is preferably a resin having a structural unit represented by the following general formula (u31-0).

[0122]

Chemical formula

[0123] In the formula (u31-0), R 21 is a hydrogen atom or an organic group. R 21 The organic group in is derived from aldehydes used in addition condensation. Among them, R 21 is preferably a hydrogen atom (derived from formaldehyde). n a21 is an integer from 1 to 3, preferably 1 or 3, more preferably 1.

[0124] The weight average molecular weight of the (p31) component is preferably from 1000 to 50000.

[0125] Polyhydroxystyrene resin (p32): As the polyhydroxystyrene resin (p32) ((p32) component), for example, a resin having a structural unit (u0) represented by the above general formula (u0-0) can be used.

[0126] (The (p32) component may have other structural units derived from polymerizable compounds such as styrene in addition to the structural unit (u0). Examples of such polymerizable compounds include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, α-methylstyrene; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, etc.).

[0127] The weight average molecular weight of the (p32) component is preferably from 1000 to 50000.

[0128] As described above, the resin component ((P) component) used in the resist composition of the embodiment contains a first resin component (P1) and a second resin component (P2). The first resin component (P1) includes a polymer compound (p10) having a structural unit (a0) derived from acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. The second resin component (P2) includes a polymer compound (p20) having both a structural unit (u0) containing a phenolic hydroxyl group and a structural unit (u1) containing an acid-decomposable group whose polarity increases by the action of an acid. Further, the dissolution rate of the first resin component (P1) in an alkaline developer is DR P1 and the dissolution rate of the second resin component (P2) in an alkaline developer is DR P2 and the dissolution rate of the mixed resin of the first resin component (P1) and the second resin component (P2) in an alkaline developer is DR MIX When this is the case, DR MIX < DR P1 and, further, DR MIX < DR P2 It is preferable to employ the first resin component (P1) and the second resin component (P2) for which there exists a mixing ratio that satisfies these conditions.

[0129] The content ratio of the (P1) component contained in the resist composition in the present embodiment may be appropriately determined according to the type of resin. For example, it is preferably 10 parts by mass or more and 50 parts by mass or less with respect to a total of 100 parts by mass of the (P1) component and the (P2) component. If the content ratio of the (P1) component is within the above-described preferable range, in the formation of a resist pattern, high sensitivity can be achieved, resolution can be enhanced, and residues are less likely to occur.

[0130] In addition, when the polymer compound (p10) is used alone as a resist composition conventionally, it can achieve a dissolution rate in an alkaline developer in which it is difficult to insolubilize in the unexposed area. Specifically, the dissolution rate in the alkaline developer is preferably 5 nm / second or more, more preferably 10 nm / second or more, and particularly preferably 10 to 10,000 nm / second. If the dissolution rate of the (p10) component in the alkaline developer is equal to or higher than the lower limit value of the above preferred range, further improvement in the dissolution rate in the exposed area can be achieved after exposure, so that residues are less likely to occur and the sensitivity is easily increased.

[0131] In addition, the polymer compound (p20) preferably has a dissolution rate in an alkaline developer of 100 nm / second or less, more preferably more than 0 nm / second and 20 nm / second or less, and particularly preferably more than 0 nm / second and 10 nm / second or less. If the dissolution rate of the (p20) component in the alkaline developer is within the above preferred range, development film loss can be suppressed and the sensitivity is easily increased.

[0132] In addition, the dissolution rate DR of the mixed resin of the (P1) component and the (P2) component in an alkaline developer MIX is preferably more than 0 nm / second and 35 nm / second or less, more preferably more than 0 nm / second and 20 nm / second or less, and particularly preferably more than 0 nm / second and 10 nm / second or less. The dissolution rate DR of the mixed resin in the alkaline developer MIX If it is within the above preferred range, development film loss is suppressed and a good remaining film pattern is easily obtained.

[0133] ≪(B) Component: Acid Generator Component≫ The (B) component is not particularly limited, and those proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyldiazomethanes and poly(bissulfonyl)diazomethanes; and various other types such as nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0134] Examples of onium salt-based acid generators include onium salts having organic cations represented by the following general formulas (ca-1) to (ca-5) in the cation moiety.

[0135] [Chemical formula] [In the formula, R 201 ~R 207 , and R 211 ~R 212 each independently represent an aryl group, a heteroaryl group, an alkyl group, or an alkenyl group, which may have a substituent. R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. R 208 ~R 209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 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 -SO2-containing cyclic group which may have a substituent. L 201 represents -C(=O)- or -C(=O)-O-. Y 201 each independently represent an arylene group, an alkylene group, or an alkenylene group. x is 1 or 2. W 201 represents an (x + 1)-valent linking group. ]

[0136] R 201 ~R 207 , and R211 ~R 212 Examples of the aryl group in ~R include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 201 ~R 207 、and R 211 ~R 212 Examples of the heteroaryl group in ~R include those in which some of the carbon atoms constituting the aryl group are substituted with heteroatoms. Examples of the heteroatom include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Examples of this heteroaryl group include a group obtained by removing one hydrogen atom from 9H-thioxanthene; examples of the substituted heteroaryl group include a group obtained by removing one hydrogen atom from 9H-thioxanthen-9-one. R 201 ~R 207 、and R 211 ~R 212 Examples of the alkyl group in ~R include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. R 201 ~R 207 、and R 211 ~R 212 Examples of the alkenyl group in ~R preferably have 2 to 10 carbon atoms. R 201 ~R 207 、and R 210 ~R 212 Examples of the substituent that ~R may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (=O), an aryl group, and groups represented by the following formulas (ca-r-1) to (ca-r-10), respectively.

[0137]

Chemical formula

[0138] In the above formulas (ca-r-1) to (ca-r-10), R’ 201 is, independently of one another, a hydrogen atom, a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent.

[0139] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0140] R’ 201 The aromatic hydrocarbon group in R’ is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R’ 201 Specific examples of the aromatic ring of the aromatic hydrocarbon group in R’ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom, or a ring in which a part of the hydrogen atoms constituting these aromatic rings or aromatic heterocyclic rings is substituted with an oxo group or the like. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom and the like. R’ 201Specific examples of the aromatic hydrocarbon group in [the relevant context] include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, anthracenyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), a group obtained by removing one hydrogen atom from a ring in which some of the hydrogen atoms constituting the aromatic ring are substituted with an oxo group or the like (for example, anthraquinone, etc.), a group obtained by removing one hydrogen atom from an aromatic heterocyclic ring (for example, 9H-thioxanthene, 9H-thioxanthen-9-one, etc.), and the like. The number of carbon atoms of the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0141] R’ 201 The cyclic aliphatic hydrocarbon group in [the relevant context] includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and as the polycycloalkane, those having 7 to 30 carbon atoms are preferable. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0142] Among them, R’ 201 As the cyclic aliphatic hydrocarbon group in, a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, a group obtained by removing one hydrogen atom from polycycloalkane is more preferable, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

[0143] 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, still more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-] and the like can be mentioned. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0144] A linear alkyl group which may have a substituent: R’ 201 As the linear alkyl group of, it may be either linear or branched. As the linear alkyl group, it preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicocyl group, docosyl group and the like can be mentioned. As the branched-chain alkyl group, it 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, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.

[0145] A chain alkenyl group which may have a substituent: R’ 201 As the chain alkenyl group of 201 , it may be either linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butenyl group, etc. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, a 2-methylpropenyl group, etc. Among the above, as the chain alkenyl group, a linear alkenyl group is preferred, a vinyl group and a propenyl group are more preferred, and a vinyl group is particularly preferred.

[0146] R’ 201 Examples of the substituent in the cyclic group, chain alkyl group or alkenyl group of 201 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, an oxo group, the cyclic group in the above R’ 201 , an alkylcarbonyl group, a thienylcarbonyl group, etc.

[0147] Among them, R’ 201 is preferably a cyclic group which may have a substituent or a chain alkyl group which may have a substituent.

[0148] R 201 ~R 203 、R 206 ~R 207 、R 211 ~R 212 When R N ~R N are bonded to each other to form a ring together with the sulfur atom in the formula, a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH- or -N(R N )-(the R Nis an alkyl group having 1 to 5 carbon atoms. It may be bonded via a functional group such as). As the ring formed, one ring containing the sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring including the sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring and the like.

[0149] In the formula (ca-3), 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, and when it is an alkyl group, they may be bonded to each other to form a ring.

[0150] In the formula (ca-3), 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 -SO2-containing cyclic group which may have a substituent. R 210 Examples of the aryl group in include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 210 Examples of the alkyl group in include a linear or cyclic alkyl group, preferably having 1 to 30 carbon atoms. R 210 Examples of the alkenyl group in preferably have 2 to 10 carbon atoms.

[0151] In the above formula (ca-4) and formula (ca-5), Y 201 each independently represents an arylene group, an alkylene group or an alkenylene group. Y 201 Examples of the arylene group in include a group obtained by removing one hydrogen atom from the aryl groups exemplified as the aromatic hydrocarbon group in R’ 201 ​ Y 201 In the alkylene group and alkenylene group in, the groups exemplified as the chain alkyl group and chain alkenyl group in R’ 201 are groups obtained by removing one hydrogen atom from the exemplified groups.

[0152] In the above formulas (ca-4) and (ca-5), x is 1 or 2. W 201 is a (x + 1)-valent, that is, a divalent or trivalent linking group. W 201 As the divalent linking group in, a divalent hydrocarbon group which may have a substituent is preferable, and the same groups as the divalent hydrocarbon groups which may have a substituent exemplified by Va 22 in the above formula (u22-0) are preferable. W 201 The divalent linking group in may be linear, branched or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group, or a group consisting only of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable. W 201 As the trivalent linking group in, a group obtained by removing one hydrogen atom from the divalent linking group in the above W 201 , a group in which the above divalent linking group is further bonded to the divalent linking group, etc. can be mentioned. W 201 As the trivalent linking group in, a group in which two carbonyl groups are bonded to an arylene group is preferable.

[0153] Specific examples of the preferable cation represented by the above formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-24), respectively.

[0154]

Chemical formula

[0155]

Chemical formula

[0156] In addition, as the cation represented by the formula (ca-1), cations represented by the following general formulas (ca-1-25) to (ca-1-35) are also preferable.

[0157]

Chemical formula

[0158]

Chemical formula

[0159] In addition, as the cation represented by the formula (ca-1), cations represented by the following chemical formulas (ca-1-36) to (ca-1-46) are also preferable.

[0160]

Chemical formula

[0161] Specific examples of the preferable cation represented by the formula (ca-2) include a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, and the like.

[0162] Specific examples of the preferable cation represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0163]

Chemical formula

[0164] In addition, as the cation represented by the formula (ca-5), cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferable.

[0165] [Chemical formula] [In the formula, R’ 212 is an alkyl group or a hydrogen atom. R’ 211 is an alkyl group.]

[0166] Among the above, the cation part is preferably a cation represented by the general formula (ca-1), and more preferably cations represented by the formulas (ca-1-1) to (ca-1-46).

[0167] Examples of the onium salt-based acid generator include onium salts having an anion represented by the following general formula (b-an1), an anion represented by the general formula (b-an2), or anions represented by the general formulas (b-1) to (b-3) in the anion part.

[0168] [Chemical formula] [In the formula, R 11 ~R 14 are each independently a fluorine atom, an alkyl group which may have a substituent, or an aryl group.]

[0169] In the above general formula (b-an1), as the alkyl group in R 11 ~R 14 , an alkyl having 1 to 20 carbon atoms is preferable, and examples thereof include linear or cyclic alkyl groups similar to Ra’ 3 in the formula (a1-r-1). R 11 ~R 14 As the aryl group in, a phenyl group or a naphthyl group is preferable. R 11 ~R14 When it is an alkyl group or an aryl group, examples of the substituent that may be present include a halogen atom, a halogenated alkyl group, an alkyl group, an alkoxy group, an alkylthio group, a hydroxyl group, a carbonyl group, etc. Examples of the alkylthio group include those having 1 to 4 carbon atoms. Among them, a halogen atom, a halogenated alkyl group, an alkyl group, an alkoxy group, and an alkylthio group are preferable.

[0170] In the above general formula (b-an1), R 11 ~R 14 is preferably a fluorine atom, a fluorinated alkyl group, or a group represented by the following general formula (b-an1’).

[0171]

Chemical formula

[0172] In the general formula (b-an1’), examples of the alkyl group having 1 to 4 carbon atoms specifically include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, etc. Among them, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable. In the general formula (b-an1’), examples of the alkoxy group having 1 to 4 carbon atoms specifically include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group, and a methoxy group and an ethoxy group are more preferable. In the general formula (b-an1’), examples of the alkylthio group having 1 to 4 carbon atoms specifically include a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, an n-butylthio group, and a tert-butylthio group, and a methylthio group and an ethylthio group are more preferable.

[0173] Preferred specific examples of the anion part represented by the general formula (b-an1) include tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ), tetrakis[(trifluoromethyl)phenyl]borate ([B(C6H4CF3)4] - ), difluorobis(pentafluorophenyl)borate ([(C6F5)2BF2] - ), trifluoro(pentafluorophenyl)borate ([(C6F5)BF3] - ), tetrakis(difluorophenyl)borate ([B(C6H3F2)4] - ), and the like. Among these, tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ) is particularly preferred.

[0174] Next, the anion represented by the general formula (b-an2) will be described.

[0175] [In the formula, R is each independently a fluorinated alkyl group having 1 to 8 carbon atoms. q is 1 to 6.] 15

[0176] Specific examples of the fluorinated alkyl group having 1 to 8 carbon atoms in the general formula (b-an2) include CF3, CF3CF2, (CF3)2CF, CF3CF2CF2, CF3CF2CF2CF2, (CF3)2CFCF2, CF3CF2(CF3)CF, and C(CF3)3.

[0177] [In the formula, R , R 101 , R 104 to R 108 are each independently an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. R 104 , R 105 ​may be bonded to each other to form a ring. R 106 ~R 107 Any two of them may be bonded to each other to form a ring. R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y 101 is a single bond or a divalent linking group containing an oxygen atom. V 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 103 ~L 105 are each independently a single bond, -CO- or -SO2-. ]

[0178] · Regarding the anion represented by the general formula (b-1) In the formula (b-1), R 101 is an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0179] (Optionally substituted cyclic group) The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. R 101 The aromatic hydrocarbon group in is the aromatic hydrocarbon ring exemplified by the divalent aromatic hydrocarbon group Va in the formula (a1-1) 1 or an aryl group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings, and a phenyl group and a naphthyl group are preferable. R 101 The cyclic aliphatic hydrocarbon group in is the group obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane exemplified by the divalent aliphatic hydrocarbon group Va in the formula (a1-1) 1 and an adamantyl group and a norbornyl group are preferable. Also, R 101The cyclic hydrocarbon group in [it] may contain a hetero atom such as a heterocyclic ring or the like, and specifically, a lactone-containing cyclic group represented by the following general formulas (a2-r-1) to (a2-r-7), an -SO2-containing cyclic group represented by the following general formulas (a5-r-1) to (a5-r-4), a substituted aryl group represented by the following chemical formulas (r-ar-1) to (r-ar-8), and a monovalent heterocyclic group represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0180]

Chemical formula

[0181] The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, in the case of only the lactone ring, it is a monocyclic group, and in the case of having another ring structure, regardless of its structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group, any group can be used without particular limitation. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) are exemplified.

[0182]

Chemical formula

[0183] In the general formulas (a2-r-1) to (a2-r-7), Ra’ 21 As the alkyl group in, an alkyl group having 1 to 6 carbon atoms is preferable. The alkyl group is preferably linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, etc. may be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Ra’ 21 As the alkoxy group in, an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in the above Ra’ 21 is linked to an oxygen atom (-O-) may be mentioned. Ra’ 21 As the halogen atom in, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. may be mentioned, and a fluorine atom is preferable. Ra’ 21 As the halogenated alkyl group in, a group in which some or all of the hydrogen atoms of the alkyl group in the above Ra’ 21 are substituted with the halogen atom may be mentioned. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0184] Ra’ 21 In -COOR” and -OC(=O)R” in, each of R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group. As the alkyl group in R”, any of linear, branched, and cyclic may be used, and the number of carbon atoms is preferably 1 to 15. When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably a methyl group or an ethyl group. When “R” is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be mentioned. Examples of the lactone-containing cyclic group in “R” include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) respectively. The carbonate-containing cyclic group in “R” is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by the general formulas (ax3-r-1) to (ax3-r-3) respectively can be mentioned. The -SO2-containing cyclic group in “R” is the same as the -SO2-containing cyclic group described later, and specifically, groups represented by the general formulas (a5-r-1) to (a5-r-4) respectively can be mentioned. Ra’ 21 The hydroxyalkyl group in preferably has 1 to 6 carbon atoms, and specifically, at least one of the hydrogen atoms of the alkyl group in the above Ra’ 21 is substituted with a hydroxyl group.

[0185] In the 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 a methylene group, an ethylene group, an n-propylene group, and an isopropyl group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. As A”, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

[0186] Specific examples of the groups represented by the following general formulas (a2-r-1) to (a2-r-7) are given below.

[0187] [Chemical formula]

[0188] [Chemical formula]

[0189] The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. Counting the carbonate ring as the first ring, in the case of only the carbonate ring, it is a monocyclic group, and when it further has another ring structure, regardless of the structure, it is called a polycyclic group. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. As the carbonate ring-containing cyclic group, any group can be used without particular limitation. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) are included.

[0190] [Chemical formula] [In the formula, Ra’ x31Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl 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 a -SO2-containing 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.

[0191] In the general formulas (ax3-r-2) to (ax3-r-3), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra’ 31 Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in are the same as those exemplified in the description of Ra’ in the general formulas (a2-r-1) to (a2-r-7). 21 Those similar to those mentioned in the description can be mentioned. Specific examples of the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are given below.

[0192]

Chemical formula

[0193] The “-SO2-containing cyclic group” refers to a cyclic group containing a ring having -SO2- in its ring skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring having -SO2- in its ring skeleton is counted as the first ring. In the case of only this ring, it is a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2-containing cyclic group is particularly preferably a cyclic group containing a -O-SO2- group in its ring skeleton, that is, a cyclic group containing a sultone ring in which -O-S- in -O-SO2- forms part of the ring skeleton. As the -SO2-containing cyclic group, more specifically, groups represented by the following general formulas (a5-r-1) to (a5-r-4) can be mentioned.

[0194]

Chemical formula

[0195] In the general formulas (a5-r-1) to (a5-r-2), A” is the same as A” in the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Ra’ 51 As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, hydroxyalkyl group in Ra’ 21 are the same as those mentioned in the description of Ra’ Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula represents an acetyl group.

[0196]

Chemical formula

[0197]

Chemical formula

[0198]

Chemical formula

[0199] R 101 Examples of the substituent in the cyclic hydrocarbon group of R include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. 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 preferable. Examples of the halogenated alkyl group as a substituent include a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, are substituted with the halogen atom.

[0200] (Optionally substituted linear alkyl group) R 101 The linear alkyl group of R may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicocyl group, a docosyl group, and the like can be mentioned. The branched-chain 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, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, and the like.

[0201] (Optionally substituted linear alkenyl group) R 101 The linear alkenyl group of R may be either linear or branched-chain, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include vinyl group, propenyl group (allyl group), butynyl group, and the like. Examples of the branched-chain alkenyl group include 1-methylpropenyl group, 2-methylpropenyl group, and the like. Among these, the propenyl group is particularly preferred as the linear alkenyl group.

[0202] R 101 Examples of the substituent in the linear alkyl group or alkenyl group of R include alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, and the cyclic group in the above R 101 and the like.

[0203] Among them, R 101 preferably has an optionally substituted cyclic group, and more preferably is an optionally substituted cyclic hydrocarbon group. More specifically, phenyl group, naphthyl group, a group obtained by removing one or more hydrogen atoms from polycycloalkane, a lactone-containing cyclic group represented by the above formulas (a2-r-1) to (a2-r-7), a -SO2-containing cyclic group represented by the above general formulas (a5-r-1) to (a5-r-4), and the like are preferred.

[0204] In formula (b-1), Y101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, the Y 101 may contain atoms other than an oxygen atom. Examples of atoms other than an oxygen atom include, for example, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like. Examples of the divalent linking group containing an oxygen atom include, for example, non-hydrocarbon-based oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-O-C(=O)-O-); combinations of the non-hydrocarbon-based oxygen atom-containing linking group and an alkylene group, and the like. A sulfonyl group (-SO2-) may be further linked to the combination. Examples of the combination include, for example, linking groups represented by the following formulas (y-al-1) to (y-al-7), respectively.

[0205]

Chemical formula

[0206] V’ 102 The divalent saturated hydrocarbon group in V’ is preferably an alkylene group having 1 to 30 carbon atoms.

[0207] V’ 101 and V’ 102 The alkylene group in V’ and V’ may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred. V’ 101 and V’ 102As the alkylene group in [description], specifically, a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; a pentamethylene group [-CH2CH2CH2CH2CH2-] and the like can be mentioned. Also, V’ 101 Or V’ 102 In [description], some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra’ in the formula (a1-r-1), and more preferably a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group. 3 As Y

[0208] Y 101 is preferably a divalent linking group containing an ester bond or an ether bond, and preferably a linking group represented by the above formulas (y-al-1) to (y-al-5) respectively.

[0209] In the formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and the fluorinated alkylene group in V 101 preferably have 1 to 4 carbon atoms. As the fluorinated alkylene group in V 101 it includes a group in which some or all of the hydrogen atoms of the alkylene group in V 101 are substituted with fluorine atoms. Among them, V101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0210] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0211] Specific examples of the anion part of the component (b-1) include, for example, when Y 101 is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y 101 is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an-1) to (an-3) can be mentioned.

[0212]

Chemical formula

[0213] R”101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent of R” is preferably the group exemplified as the cyclic aliphatic hydrocarbon group in the above R 101 . Examples of the substituent include the same substituents as those which may substitute the cyclic aliphatic hydrocarbon group in R 101 .

[0214] R” 103 The aromatic cyclic group which may have a substituent of R” is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the above R 101 . Examples of the substituent include the same substituents as those which may substitute the aromatic hydrocarbon group in R 101 .

[0215] R” 101 The linear alkyl group which may have a substituent of R” is preferably the group exemplified as the linear alkyl group in the above R 101 . The linear alkenyl group which may have a substituent of R” is preferably the group exemplified as the linear alkenyl group in the above R 103 . 101 V” 101 is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably -CF2-, -CF2CF2-, -CHFCF2-, -CF(CF3)CF2-, -CH(CF3)CF2-.

[0216] Specific examples of the anion represented by the general formula (an-1) are given below. However, it is not limited thereto.

[0217]

Chemical formula

[0218] Specific examples of the anion represented by the general formula (an-2) are given below. However, it is not limited thereto.

[0219] ​ [Chemical formula]

[0220] Specific examples of the anion represented by the general formula (an-3) are given below. However, it is not limited thereto.

[0221] [Chemical formula]

[0222] · Regarding the anion represented by the general formula (b-2) In the formula (b-2), R 104 , R 105 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof are the same as those of R 101 in the formula (b-1). However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 are preferably a chain-like alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and still more preferably 1 to 3. The number of carbon atoms of the chain-like alkyl group of R 104 , R 105 is preferably smaller within the above range of the number of carbon atoms for reasons such as good solubility in the resist solvent. Also, R 104 , R 105In the case of the chain alkyl group, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and the transparency to high-energy light or electron beams of 200 nm or less is improved, which is preferable. 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 substituted by fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof are the same as those of V 101 in formula (b-1). In formula (b-2), L 101 ~L 102 are each independently a single bond or an oxygen atom.

[0223] Specific examples of the anion represented by the general formula (b-2) are given below. However, it is not limited thereto.

[0224]

Chemical formula

[0225] ·Regarding the anion represented by the general formula (b-3) In formula (b-3), R 106 ~R 108 are each 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 examples thereof are the same as those of R 101 in formula (b-1). L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0226] Specific examples of the anion represented by the general formula (b-3) are given below. However, it is not limited thereto.

[0227] [Chemical formula]

[0228] Among these, the anion part of the onium salt is preferably an anion represented by general formula (b-an1), an anion represented by general formula (b-an2), or an anion represented by general formula (b-2). Among these, the anion represented by general formula (b-an2) is more preferable.

[0229] Also, the anion part of the onium salt may be a halogen anion, a phosphate anion, an antimonate anion (SbF6 - ), or an arsenate anion (AsF6 - ). Examples of the halogen anion include chlorine and bromine, and examples of the phosphate anion include PF6 - .

[0230] As component (B), other acid generators other than those described above may be used.

[0231] Examples of such other acid generators include 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-ethyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-propyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dimethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dipropoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-ethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-propoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-methylenedioxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-(3,4-methylenedioxyphenyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxystyrylphenyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxystyrylphenyl)-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(5-methyl-2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,5-(Dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, halogen-containing triazine compounds such as tris(1,3-dibromopropyl)-1,3,5-triazine and tris(2,3-dibromopropyl)-1,3,5-triazine, and halogen-containing triazine compounds represented by the following general formula (b3) such as tris(2,3-dibromopropyl)isocyanurate are included.,

[0232]

Chemical formula

[0233] In the above general formula (b3), Rb 9 and Rb 10 and Rb 11 each independently represents a halogenated alkyl group.,

[0234] In addition, as other acid generators, α-(p-toluenesulfonyloxyimino)-phenylacetonitrile, α-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile, α-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile, α-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, and compounds represented by the following general formula (b4) containing an oxime sulfonate group are included.,

[0235]

Chemical formula

[0236] In the above general formula (b4), Rb 12 represents a monovalent, divalent, or trivalent organic group, and Rb 13represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group, or aromatic compound group, and n represents the number of repeating units of the structure in parentheses.

[0237] In the general formula (b4) above, the aromatic compound group refers to a group of a compound that exhibits the physical and chemical properties peculiar to aromatic compounds. Examples include aryl groups such as phenyl group and naphthyl group, and heteroaryl groups such as furyl group and thienyl group. These may have one or more appropriate substituents on the ring, such as a halogen atom, an alkyl group, an alkoxy group, a nitro group, etc. Also, Rb 13 is particularly preferably an alkyl group having 1 to 6 carbon atoms, and examples include methyl group, ethyl group, propyl group, and butyl group. In particular, Rb 12 is an aromatic compound group, and Rb 13 is a compound that is an alkyl group having 1 to 4 carbon atoms is preferred.

[0238] As the acid generator represented by the general formula (b4), when n = 1, Rb 12 is any of a phenyl group, a methylphenyl group, and a methoxyphenyl group, and Rb 13 is a methyl group, and specific examples include α-(methylsulfonyloxyimino)-1-phenylacetonitrile, α-(methylsulfonyloxyimino)-1-(p-methylphenyl)acetonitrile, α-(methylsulfonyloxyimino)-1-(p-methoxyphenyl)acetonitrile, [2-(propylsulfonyloxyimino)-2,3-dihydroxythiophene-3-ylidene](o-tolyl)acetonitrile, and the like. When n = 2, examples of the acid generator represented by the general formula (b4) specifically include acid generators represented by the following formulas.

[0239]

Chemical formula

[0240] In addition, examples of other acid generators include onium salts having a naphthalene ring in the cationic part. The phrase "having a naphthalene ring" means having a structure derived from naphthalene, which means having at least two ring structures and maintaining their aromaticity. This naphthalene ring may have substituents such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (having one free valence) or a divalent group (having two or more free valences) or more, but it is preferably a monovalent group (however, in this case, the free valence is counted excluding the part bonded to the above substituent). The number of naphthalene rings is preferably 1 to 3.

[0241] As the cationic part of such an onium salt having a naphthalene ring in the cationic part, a structure represented by the following general formula (b5) is preferable.

[0242]

Chemical formula

[0243] In the above general formula (b5), Rb 14 , Rb 15 , Rb 16 Among them, at least one represents a group represented by the following general formula (b6), and the rest represent a linear or branched alkyl group having 1 to 6 carbon atoms, a phenyl group which may have a substituent, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Alternatively, one of Rb 14 , Rb 15 , Rb 16 is a group represented by the following general formula (b6), and the remaining two are each independently a linear or branched alkylene group having 1 to 6 carbon atoms, and the ends thereof may be bonded to form a ring.

[0244]

Chemical formula

[0245] In the general formula (b6) above, Rb 17 and Rb 18 each independently represent a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or a linear or branched alkyl group having 1 to 6 carbon atoms, and Rb 19 represents a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms which may have a substituent. l and m each independently represent an integer from 0 to 2, and l + m is 3 or less. However, when there are a plurality of Rb 17 , they may be the same as or different from each other. Also, when there are a plurality of Rb 18 , they may be the same as or different from each other.

[0246] Regarding the above Rb 14 , Rb 15 , Rb 16 , the number of the groups represented by the general formula (b6) among them is preferably 1 from the viewpoint of the stability of the compound, and the rest are linear or branched alkylene groups having 1 to 6 carbon atoms, and the ends of these may be bonded to form a ring. In this case, the above two alkylene groups form a 3- to 9-membered ring including a sulfur atom. The number of atoms (including the sulfur atom) constituting the ring is preferably 5 to 6.

[0247] Examples of the substituent that the above alkylene group may have include an oxygen atom (in this case, forming a carbonyl group together with the carbon atom constituting the alkylene group), a hydroxyl group, and the like.

[0248] Examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, a linear or branched alkyl group having 1 to 6 carbon atoms, and the like.

[0249] Examples of those suitable as these cation moieties include those represented by the following formulas (b7), (b8), and (b18), and particularly, the structure represented by the following formula (b18) is preferable.

[0250]

Chemical formula

[0251] As such a cationic moiety, it may be an iodonium salt or a sulfonium salt, but a sulfonium salt is desirable from the viewpoint of acid generation efficiency and the like.

[0252] Therefore, as a suitable anion moiety of an onium salt having a naphthalene ring in the cationic moiety, an anion capable of forming a sulfonium salt is desirable.

[0253] As the anion moiety of such an acid generator, it is a fluoroalkylsulfonate ion or an arylsulfonate ion in which part or all of the hydrogen atoms are fluorinated.

[0254] The alkyl group in the fluoroalkylsulfonate ion may be linear, branched or cyclic with 1 to 20 carbon atoms, and is preferably 1 to 10 carbon atoms from the bulkiness and diffusion distance of the generated acid. In particular, branched or cyclic ones are preferable because of their short diffusion distance. Also, since they can be synthesized inexpensively, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, etc. can be mentioned as preferable ones.

[0255] The aryl group in the arylsulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples include a phenyl group and a naphthyl group which may or may not be substituted with an alkyl group or a halogen atom. In particular, an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized inexpensively. Specific examples of preferable ones include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, a methylnaphthyl group, etc.

[0256] In the above-mentioned fluoroalkylsulfonate ion or arylsulfonate ion, when part or all of the hydrogen atoms are fluorinated, the fluorination rate is preferably 10 to 100%, more preferably 50 to 100%. In particular, those in which all hydrogen atoms are replaced by fluorine atoms are preferred because the acid strength becomes stronger. Specific examples of such substances include trifluoromethanesulfonate, perfluorobutanesulfonate, perfluorooctanesulfonate, perfluorobenzenesulfonate, and the like.

[0257] Among these, preferred anion moieties include those represented by the following general formula (b9).

[0258]

Chemical formula

[0259] In the above general formula (b9), Rb 20 is a group represented by the following general formula (b10), (b11), or a group represented by the following formula (b12).

[0260]

Chemical formula

[0261] In the above general formula (b10), x represents an integer of 1 to 4. In the above general formula (b11), Rb 21 represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, or a linear or branched alkoxy group having 1 to 6 carbon atoms, and y represents an integer of 1 to 3. Among these, from the viewpoint of safety, trifluoromethanesulfonate and perfluorobutanesulfonate are preferred.

[0262] In addition, as the anion moiety, it is preferable to use those containing nitrogen, which are represented by the following general formula (b13) and general formula (b14), respectively.

[0263]

Chemical formula

[0264] In the above general formula (b13), Xb represents a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, the number of carbon atoms of the alkylene group is 2 to 6, preferably 3 to 5, and most preferably 3 carbon atoms. Further, in the above general formula (b14), Yb and Zb each independently represent a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, the number of carbon atoms of the alkyl group is 1 to 10, preferably 1 to 7, and more preferably 1 to 3.

[0265] It is preferable that the smaller the number of carbon atoms of the alkylene group of Xb or the alkyl groups of Yb and Zb, the better the solubility in the organic solvent.

[0266] Also, in the alkylene group of Xb or the alkyl groups of Yb and Zb, it is preferable that the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength. The ratio of fluorine atoms, that is, the fluorination rate, in the alkylene group or alkyl group is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkylene group or perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0267] Preferred examples of the onium salt having a naphthalene ring in the cation moiety include compounds represented by the following formulas (b15), (b16), and (b17), and the compound represented by the following formula (b17) is more preferred.

[0268]

Chemical formula

[0269] In addition, examples of other acid generators include bissulfonyldiazomethanes such as bis(p-toluenesulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane; nitrobenzyl derivatives such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, nitrobenzyl carbonate, dinitrobenzyl carbonate; sulfonic acid esters such as pyrogallol trimesylate, pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate, N-methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide, N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-hydroxyphthalimide, N-hydroxynaphthalimide; onium salts such as diphenyliodonium hexafluorophosphate, (4-methoxyphenyl)phenyliodonium trifluoromethanesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, (p-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate; benzoin tosylates such as benzoin tosylate, α-methylbenzoin tosylate; and other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts, benzyl carbonate, and the like.

[0270] Preferred among other acid generators are compounds having a cation represented by the above general formula (b5) in the cation moiety, wherein Rb in the above general formula (b6) 17 and Rb 18 each independently represent a linear or branched alkoxy group having 1 to 6 carbon atoms, and it is preferred that Rb 19 is a single bond.

[0271] The acid generator (B) may be used alone or in combination of two or more thereof. The content of the acid generator (B) in the resist composition is not particularly limited as long as patterning is possible, and it may be arbitrarily determined in consideration of the type of the acid generator, the resin component, other additives, the film thickness used, etc. For example, the content of the acid generator (B) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin component ((P) component).

[0272] ≪Other components≫ The resist composition used in the resist pattern forming method of the present embodiment may further contain components other than the above-described (P) component and (B) component (other components) as necessary. Examples of such other components include the following (F) component, (E) component, (C) component, (S) component, etc.

[0273] (F) component: Regarding the acid diffusion control agent component The resist composition of the present embodiment preferably further contains an acid diffusion control agent component (hereinafter also referred to as "(F) component") for improving the shape of the resist pattern used as a mold and the standing stability of the resist film. As the (F) component, a nitrogen-containing compound (hereinafter also referred to as "(F1) component") is preferable, and an organic carboxylic acid or an oxo acid of phosphorus or a derivative thereof (hereinafter also referred to as "(F2) component") can be further contained as necessary.

[0274] (F1) component: Regarding the nitrogen-containing compound (F1) Components include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-pentylamine (triamylamine), n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, tribenzylamine, diethanolamine, triethanolamine, ethylenediamine, N,N,N’,N’-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4’-diaminodiphenylmethane, 4,4’-diaminodiphenyl ether, 4,4’-diaminobenzophenone, 4,4’-diaminodiphenylamine, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3,-tetramethylurea, 1,3-diphenylurea, imidazole, benzimidazole, 4-methylimidazole, 8-hydroxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri(2-pyridyl)-S-triazine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, pyridine, etc.

[0275] (F1) components include commercially available hindered amine compounds such as Adeka Stab LA-52, Adeka Stab LA-57, Adeka Stab LA-63P, Adeka Stab LA-68, Adeka Stab LA-72, Adeka Stab LA-77Y, Adeka Stab LA-77G, Adeka Stab LA-81, Adeka Stab LA-82, Adeka Stab LA-87 (all manufactured by ADEKA CORPORATION); pyridines substituted at the 2,6-position or 2,4,6-position with substituents such as hydrocarbon groups, such as 2,6-diphenylpyridine, 2,6-di-tert-butylpyridine, 2,4,6-triphenylpyridine, 2,4,6-tri-tert-butylpyridine; piperidines substituted at the substitutable sites with substituents such as hydrocarbon groups, such as 2,6-dimethylpiperidine, 1,3,5-trimethylpiperidine, 2,4,6-trimethylpiperidine, 2,2,6,6-tetramethylpiperidine, etc. can also be used.

[0276] (F1) component may be used alone or in combination of two or more. The content of the (F1) component in the resist composition is usually in the range of 0 parts by mass or more and 5 parts by mass or less, preferably in the range of 0 parts by mass or more and 3 parts by mass or less, and more preferably 0 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the resin component ((P) component). By setting the above range, the resist pattern shape, standing time stability, etc. are improved.

[0277] (F2) component: Regarding organic carboxylic acids or oxoacids of phosphorus or their derivatives Among the (F2) components, as the organic carboxylic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid are preferred, and salicylic acid is particularly preferred.

[0278] Among the components of (F2), examples of the oxo acid of phosphorus or its derivatives include derivatives such as phosphoric acid or its esters such as phosphoric acid, dibutyl phosphate, and diphenyl phosphate; phosphonic acids or their derivatives such as phosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate; phosphinic acids or their derivatives such as phosphinic acid and phenylphosphinic acid; and the like. Among these, phosphonic acid is particularly preferred.

[0279] The component (F2) may be used alone or in combination of two or more. The content of the component (F2) in the resist composition is usually in the range of 0 parts by mass or more and 5 parts by mass or less, preferably in the range of 0 parts by mass or more and 3 parts by mass or less, and more preferably 0 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the resin component ((P) component).

[0280] Also, as the component (F), it is preferable to use the component (F2) and the component (F1) in equal amounts.

[0281] Component (E): Regarding sulfur-containing compounds When the resist composition of this embodiment is used for pattern formation on a metal substrate, it preferably further contains a sulfur-containing compound (hereinafter also referred to as "component (E)"). The component (E) is a compound containing a sulfur atom capable of coordinating to a metal. For a compound that can generate two or more tautomers, when at least one tautomer contains a sulfur atom that coordinates to the metal constituting the metal layer, the compound falls within the category of sulfur-containing compounds. When forming a resist pattern used as a plating mold on the surface made of a metal such as Cu, defects in the cross-sectional shape such as footing are likely to occur. However, when the resist composition contains the component (E), even when forming a resist pattern on the metal surface of the substrate, defects in the cross-sectional shape such as footing are less likely to occur. When the resist composition is used for pattern formation on a substrate other than a metal substrate, the resist composition does not particularly need to contain the component (E). In addition, there are no particular problems caused by the resist composition containing the component (E) when used for pattern formation on a substrate other than a metal substrate.

[0282] Sulfur atoms that can coordinate to a metal are contained in a sulfur-containing compound, for example, as a mercapto group (-SH), a thiocarboxy group (-CO-SH), a dithiocarboxy group (-CS-SH), or a thiocarbonyl group (-CS-). Since it is easy to coordinate to a metal and has an excellent effect of suppressing footing, those having a mercapto group are preferable as the component (E).

[0283] Preferable examples of the sulfur-containing compound having a mercapto group include compounds represented by the following general formula (e1).

[0284] [Chemical formula] [In the formula, R e1 and R e2 each independently represent a hydrogen atom or an alkyl group. R e3 represents a single bond or an alkylene group. R e4 represents a u-valent aliphatic group that may contain an atom other than carbon. u represents an integer of 2 or more and 4 or less. ]

[0285] R e1 and R e2 When they are alkyl groups, the alkyl group may be linear or branched, and is preferably linear. R e1 and R e2 When they are alkyl groups, the number of carbon atoms of the alkyl group is not particularly limited as long as it does not inhibit the object of the present invention. The number of carbon atoms of the alkyl group is preferably 1 or more and 4 or less, particularly preferably 1 or 2, and most preferably 1. R e1 and R e2As a combination, it is preferable that one is a hydrogen atom and the other is an alkyl group, and it is particularly preferable that one is a hydrogen atom and the other is a methyl group.

[0286] R e3 When R is an alkylene group, the alkylene group may be linear or branched, and is preferably linear. R e3 When R is an alkylene group, the number of carbon atoms of the alkylene group is not particularly limited as long as it does not inhibit the object of the present invention. The number of carbon atoms of the alkylene group is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, particularly preferably 1 or 2, and most preferably 1.

[0287] R e4 is an aliphatic group having a valence of 2 or more and 4 or less, which may contain atoms other than carbon. R e4 Examples of the atoms other than carbon that R may contain include a nitrogen atom, an oxygen atom, a sulfur atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. R e4 The structure of the aliphatic group that R is may be linear, branched, cyclic, or a structure combining these structures.

[0288] Among the compounds represented by formula (e1), the compounds represented by the following formula (e2) are more preferable.

[0289]

Chemical formula

[0290] Among the compounds represented by the above formula (e2), the following compounds are preferable.

[0291]

Chemical formula

[0292] Compounds represented by the following formulas (e3-L1) to (e3-L7) are also preferable examples of sulfur-containing compounds having a mercapto group.

[0293]

Chem.

[0294] Preferable specific examples of the sulfur-containing compounds having a mercapto group and represented by the above formulas (e3-L1) to (e3-L7) include the following compounds.

[0295]

Chem.

[0296] Compounds represented by the following formulas (e3-1) to (e3-4) are also preferable examples of sulfur-containing compounds having a mercapto group.

[0297]

Chem.

[0298] Preferable specific examples of the mercapto compounds represented by the above formulas (e3-1) to (e3-4) include the following compounds.

[0299]

Chem.

[0300] Further, as a preferable example of the compound having a mercapto group, a compound represented by the following formula (e4) can be mentioned.

[0301] [Chemical formula] [In formula (e4), R e5 is a group selected from the group consisting of a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkylthio group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a mercaptoalkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, and a halogen atom. n1 is an integer of 0 or more and 3 or less. n0 is an integer of 0 or more and 3 or less. When n1 is 2 or 3, a plurality of R e5 may be the same or different.]

[0302] R e5 When it is an alkyl group which may have a hydroxyl group having 1 to 4 carbon atoms, specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these alkyl groups, a methyl group, a hydroxymethyl group, and an ethyl group are preferable.

[0303] R e5 When it is an alkoxy group having 1 to 4 carbon atoms, specific examples include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, and a tert-butyloxy group. Among these alkoxy groups, a methoxy group and an ethoxy group are preferable, and a methoxy group is more preferable.

[0304] R e5When it is an alkylthio group having 1 to 4 carbon atoms, specific examples include methylthio group, ethylthio group, n-propylthio group, isopropylthio group, n-butylthio group, isobutylthio group, sec-butylthio group, and tert-butylthio group. Among these alkylthio groups, methylthio group and ethylthio group are preferred, and methylthio group is more preferred.

[0305] R e5 When it is a hydroxyalkyl group having 1 to 4 carbon atoms, specific examples include hydroxymethyl group, 2-hydroxyethyl group, 1-hydroxyethyl group, 3-hydroxy-n-propyl group, 4-hydroxy-n-butyl group, etc. Among these hydroxyalkyl groups, hydroxymethyl group, 2-hydroxyethyl group, and 1-hydroxyethyl group are preferred, and hydroxymethyl group is more preferred.

[0306] R e5 When it is a mercaptoalkyl group having 1 to 4 carbon atoms, specific examples include mercaptomethyl group, 2-mercaptoethyl group, 1-mercaptoethyl group, 3-mercapto-n-propyl group, 4-mercapto-n-butyl group, etc. Among these mercaptoalkyl groups, mercaptomethyl group, 2-mercaptoethyl group, and 1-mercaptoethyl group are preferred, and mercaptomethyl group is more preferred.

[0307] R e5 When it is a halogenated alkyl group having 1 to 4 carbon atoms, examples of the halogen atom contained in the halogenated alkyl group include fluorine, chlorine, bromine, iodine, etc. R e5When it is a halogenated alkyl group having 1 to 4 carbon atoms, specific examples include chloromethyl group, bromomethyl group, iodomethyl group, fluoromethyl group, dichloromethyl group, dibromomethyl group, difluoromethyl group, trichloromethyl group, tribromomethyl group, trifluoromethyl group, 2-chloroethyl group, 2-bromoethyl group, 2-fluoroethyl group, 1,2-dichloroethyl group, 2,2-difluoroethyl group, 1-chloro-2-fluoroethyl group, 3-chloro-n-propyl group, 3-bromo-n-propyl group, 3-fluoro-n-propyl group, 4-chloro-n-butyl group and the like. Among these halogenated alkyl groups, chloromethyl group, bromomethyl group, iodomethyl group, fluoromethyl group, dichloromethyl group, dibromomethyl group, difluoromethyl group, trichloromethyl group, tribromomethyl group, trifluoromethyl group are preferable, and chloromethyl group, dichloromethyl group, trichloromethyl group, trifluoromethyl group are more preferable.

[0308] R e5 When it is a halogen atom, specific examples include fluorine, chlorine, bromine, or iodine.

[0309] In formula (e4), n1 is an integer of 0 or more and 3 or less, and 1 is more preferable. When n1 is 2 or 3, a plurality of R e5 may be the same or different.

[0310] In the compound represented by formula (e4), the substitution position of R e5 on the benzene ring is not particularly limited. The substitution position of R e5 on the benzene ring is preferably the meta position or the para position with respect to the bonding position of -(CH2) n0 -SH.

[0311] As the compound represented by formula (e4), as R e5 it is preferably a compound having at least one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group, and R e5More preferably, the compound has one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group. For the compound represented by the formula (e4), R e5 When the compound has one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group, the substitution position of the alkyl group, the hydroxyalkyl group, or the mercaptoalkyl group on the benzene ring is -(CH2) n0 It is preferably in the meta or para position relative to the bonding position of -SH, and more preferably in the para position.

[0312] In the formula (e4), n0 is an integer of 0 or more and 3 or less. Since the compound is easy to prepare and obtain, n is preferably 0 or 1, and more preferably 0.

[0313] Specific examples of the compound represented by formula (e4) include p-mercaptophenol, p-thiocresol, m-thiocresol, 4-(methylthio)benzenethiol, 4-methoxybenzenethiol, 3-methoxybenzenethiol, 4-ethoxybenzenethiol, 4-isopropyloxybenzenethiol, 4-tert-butoxybenzenethiol, 3,4-dimethoxybenzenethiol, 3,4,5-trimethoxybenzenethiol, 4-ethylbenzenethiol, 4-isopropylbenzenethiol, 4-n-butylbenzenethiol, 4-tert-butylbenzenethiol, 3-ethylbenzenethiol, 3-isopropylbenzenethiol, 3-n-butylbenzenethiol, 3-tert-butylbenzenethiol, 3,5-dimethylbenzenethiol, 3,4-dimethylbenzenethiol, 3-tert-butyl-4-methylbenzenethiol, 3-tert-4-methylbenzenethiol, 3-tert-butyl-5-methylbenzenethiol, 4-tert-butyl-3-methylbenzenethiol, 4-mercaptobenzyl alcohol, 3-mercaptobenzyl alcohol, 4-(mercaptomethyl)phenol, 3-(mercaptomethyl)phenol, 1,4-di(mercaptomethyl)phenol, 1,3-di(mercaptomethyl)phenol, 4-fluorobenzenethiol, 3-fluorobenzenethiol, 4-chlorobenzenethiol, 3-chlorobenzenethiol, 4-bromobenzenethiol, 4-iodobenzenethiol, 3-bromobenzenethiol, 3,4-dichlorobenzenethiol, 3,5-dichlorobenzenethiol, 3,4-difluorobenzenethiol, 3,5-difluorobenzenethiol, 4-mercaptocatechol, 2,6-di-tert-butyl-4-mercaptophenol, 3,5-di-tert-butyl-4-methoxybenzenethiol, 4-bromo-3-methylbenzenethiol, 4-(trifluoromethyl)benzenethiol, 3-(trifluoromethyl)benzenethiol, 3,5-bis(trifluoromethyl)benzenethiol, 4-methylthiobenzenethiol, 4-ethylthiobenzenethiol, 4-n-butylthiobenzenethiol, 4-tert-butylthiobenzenethiol, and the like.

[0314] Examples of the sulfur-containing compound having a mercapto group include compounds containing a nitrogen-containing aromatic heterocyclic ring substituted with a mercapto group, and tautomers of compounds containing a nitrogen-containing aromatic heterocyclic ring substituted with a mercapto group. Preferable specific examples of the nitrogen-containing aromatic heterocyclic ring include imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, indole, indazole, benzimidazole, benzoxazole, benzothiazole, 1H-benzotriazole, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, 1,8-naphthyridine.

[0315] Preferable specific examples of the nitrogen-containing heterocyclic compound suitable as the sulfur-containing compound and the tautomers of the nitrogen-containing heterocyclic compound include the following compounds, respectively.

[0316] [Chemical formula]

[0317] Component (E) may be used alone or in combination of two or more. When the resist composition contains component (E), the content of component (E) in the resist composition is preferably 0.01 part by mass or more and 5 parts by mass or less, more preferably 0.02 part by mass or more and 3 parts by mass or less, and particularly preferably 0.02 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the resin component ((P) component).

[0318] Component (C): Regarding the Lewis acidic compound The resist composition of the present embodiment may contain a Lewis acidic compound (hereinafter also referred to as “component (C)”). Here, the “Lewis acidic compound” means a compound having an empty orbital capable of receiving at least one electron pair and acting as an electron pair acceptor. (C) component is not particularly limited as long as it meets the above definition and is recognized as a Lewis acidic compound by those skilled in the art. As the (C) component, a compound that does not correspond to a Brønsted acid (protonic acid) is preferably used. Specific examples of the (C) component include boron fluoride, ether complexes of boron fluoride (e.g., BF3·Et2O, BF3·Me2O, BF3·THF, etc. Et is an ethyl group, Me is a methyl group, and THF is tetrahydrofuran), organic boron compounds (e.g., tri-n-octyl borate, tri-n-butyl borate, triphenyl borate, triphenyl boron, etc.), titanium chloride, aluminum chloride, aluminum bromide, gallium chloride, gallium bromide, indium chloride, thallium trifluoroacetate, tin chloride, zinc chloride, zinc bromide, zinc iodide, zinc trifluoromethanesulfonate, zinc acetate, zinc nitrate, zinc tetrafluoroborate, manganese chloride, manganese bromide, nickel chloride, nickel bromide, nickel cyanide, nickel acetylacetonate, cadmium chloride, cadmium bromide, stannous chloride, stannous bromide, stannous sulfate, stannous tartrate, etc. Also, other specific examples of the (C) component include chlorides, bromides, sulfates, nitrates, carboxylates or trifluoromethanesulfonates of rare earth metal elements; cobalt chloride, ferrous chloride, yttrium chloride, etc. Here, examples of the rare earth metal elements include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, etc.

[0319] Since the (C) component is easily available and has good effects when added, those containing a Lewis acidic compound containing a Group 13 element of the periodic table are preferred. Here, examples of the Group 13 elements of the periodic table include boron, aluminum, gallium, indium, thallium. Among the Group 13 elements of the periodic table described above, boron is preferred because of the ease of obtaining the component (C) and the particularly excellent addition effect. That is, it is preferable that the component (C) contains a Lewis acidic compound containing boron.

[0320] Examples of the Lewis acidic compound containing boron include boron halides such as boron fluoride, ether complexes of boron fluoride, boron chloride, boron bromide, etc.; and various organic boron compounds. As the Lewis acidic compound containing boron, an organic boron compound is preferred because the content ratio of halogen atoms in the Lewis acidic compound is small and it is easy to apply to applications where the resist composition is required to have a low halogen content.

[0321] Preferable examples of the organic boron compound include the following formula (c1): B(R c1 ) n1 (OR c2 ) (3-n1) ···(c1) [(In formula (c1), R c1 and R c2 are each independently a hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may have one or more substituents, n1 is an integer of 0 to 3, and when there are a plurality of R c1 , two of the plurality of R c1 may be bonded to each other to form a ring, and when there are a plurality of OR c2 , two of the plurality of OR c2 may be bonded to each other to form a ring.)] Examples of the boron compound represented by are included. The resist composition preferably contains one or more of the boron compounds represented by the above formula (c1) as the component (C).

[0322] In formula (c1), R c1 and R c2When it is a hydrocarbon group, the number of carbon atoms in the hydrocarbon group is 1 or more and 20 or less. The hydrocarbon group having 1 or more and 20 or less carbon atoms may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a hydrocarbon group composed of a combination of an aliphatic group and an aromatic group. As the hydrocarbon group having 1 or more and 20 or less carbon atoms, a saturated aliphatic hydrocarbon group or an aromatic hydrocarbon group is preferable. R c1 and R c2 The number of carbon atoms in the hydrocarbon group as R and R is preferably 1 or more and 10 or less. When the hydrocarbon group is an aliphatic hydrocarbon group, the number of carbon atoms is more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 4 or less. R c1 and R c2 The hydrocarbon group as R and R may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and a saturated hydrocarbon group is preferable. R c1 and R c2 When the hydrocarbon group as R and R is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be linear, branched, cyclic, or a combination of these structures.

[0323] Preferable specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthalene-1-yl group, a naphthalene-2-yl group, a 4-phenylphenyl group, a 3-phenylphenyl group, and a 2-phenylphenyl group. Among these, a phenyl group is preferable.

[0324] As the saturated aliphatic hydrocarbon group, an alkyl group is preferable. Preferable specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, and an n-decyl group.

[0325] R c1 and R c2The hydrocarbon group as such may have one or more substituents. Examples of the substituent include a halogen atom, a hydroxyl group, an alkyl group, an aralkyl group, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, an acyloxy group, an acylthio group, an alkoxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an amino group, an N-monosubstituted amino group, an N,N-disubstituted amino group, a carbamoyl group (-CO-NH2), an N-monosubstituted carbamoyl group, an N,N-disubstituted carbamoyl group, a nitro group, a cyano group, and the like. The number of carbon atoms of the substituent is not particularly limited as long as it does not inhibit the object of the present invention, but is preferably 1 or more and 10 or less, more preferably 1 or more and 6 or less.

[0326] Preferable specific examples of the organic boron compound represented by the above formula (c1) include the following compounds. In the following formulas, Pen represents a pentyl group, Hex represents a hexyl group, Hep represents a heptyl group, Oct represents an octyl group, Non represents a nonyl group, and Dec represents a decyl group.

[0327]

Chemical formula

[0328]

Chemical formula

[0329]

Chemical formula

[0330]

Chemical formula

[0331]

Chemical formula

[0332] The component (C) may be used alone or in combination of two or more kinds. When the resist composition contains the component (C), the content of the component (C) in the resist composition is preferably in the range of 0.01 part by mass or more and 5 parts by mass or less, more preferably in the range of 0.01 part by mass or more and 3 parts by mass or less, and still more preferably in the range of 0.05 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the resin component ((P) component).

[0333] If desired, additives that are miscible, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc., can be appropriately added and contained in the resist composition.

[0334] Component (S): Regarding the organic solvent component The resist composition can be produced by dissolving the materials in the organic solvent component ((S) component). The component (S) may be any one that can dissolve each component to be used and form a uniform solution, and one or more arbitrary ones can be appropriately selected from those known as solvents for chemically amplified resists and used. (S) components include, for example, lactones such as γ-butyrolactone (GBL); ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, etc. of the above polyhydric alcohols or compounds having an ester bond, or compounds having an ether bond such as monophenyl ether, etc., derivatives of polyhydric alcohols [among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethyl benzene, diethyl benzene, pentyl benzene, isopropyl benzene, toluene, xylene, cymene, mesitylene, etc., dimethyl sulfoxide (DMSO), etc.

[0335] (S) component may be used alone or as a mixed solvent of two or more kinds. Among them, PGMEA, 3-methoxybutyl acetate, butyl acetate, 2-heptanone are preferred.

[0336] (S) The amount of use is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, when used in a film thickness application where the film thickness of the resist film obtained by a spin coating method or the like is 1 μm or more, it is preferable that the solid content concentration of the resist composition is in the range of 15% by mass to 65% by mass.

[0337] The resist composition may further contain a polyvinyl resin in order to improve plasticity. Specific examples of the polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl phenol, or a copolymer thereof. From the viewpoint of the low glass transition point, the polyvinyl resin is preferably polyvinyl methyl ether.

[0338] In addition, the resist composition can further contain an adhesion aid in order to improve the adhesion to the substrate.

[0339] Further, the resist composition may further contain a surfactant in order to improve coatability, defoaming property, leveling property, etc. As the surfactant, for example, a fluorine-based surfactant or a silicone-based surfactant is preferably used. Specific examples of the fluorine-based surfactant include commercially available fluorine-based surfactants such as BM-1000, BM-1100 (both manufactured by BM Chemie); Megafac F142D, Megafac F172, Megafac F173, Megafac F183 (all manufactured by Dainippon Ink and Chemicals, Inc.); Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M Limited); Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.); SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicone Co., Ltd.), but are not limited thereto. As the silicone surfactant, an unmodified silicone surfactant, a polyether-modified silicone surfactant, a polyester-modified silicone surfactant, an alkyl-modified silicone surfactant, an aralkyl-modified silicone surfactant, a reactive silicone surfactant, etc. can be preferably used. As the silicone surfactant, a commercially available silicone surfactant can be used. Specific examples of the commercially available silicone surfactant include Painted M (manufactured by Toray Dow Corning Co., Ltd.), Topica K1000, Topica K2000, Topica K5000 (all manufactured by Takachiho Sangyo Co., Ltd.), XL-121 (a polyether-modified silicone surfactant, manufactured by Clariant), BYK-310 (a polyester-modified silicone surfactant, manufactured by BYK), etc.

[0340] Further, in the resist composition, an acid, an acid anhydride, or a high-boiling solvent can be further contained in order to finely adjust the solubility in an alkali developer.

[0341] Examples of acids and acid anhydrides include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, cinnamic acid; hydroxy monocarboxylic acids such as lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, syringic acid; polyvalent carboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, trimellitic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarballylic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic anhydride, 1,2,3,4-butanetetracarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bisanhydromellitate, glycerin trisanhydromellitate, etc.

[0342] Examples of high-boiling solvents include N-methylformamide, N,N-dimethylformamide, N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzyl ethyl ether, dihexyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate, ethyl phthalylethyl glycolate, etc.

[0343] The amount of the compound used for finely adjusting the solubility in the alkali developer as described above can be adjusted according to the use and coating method, and is not particularly limited as long as the composition can be uniformly mixed, but it is 60% by mass or less, preferably 40% by mass or less, based on the total mass of the resulting composition.

[0344] In the resist pattern forming method of the present embodiment described above, in the base resin of the resist composition, as the component (P1), a polymer compound (p10) having the structural unit (a0) is employed, and as the component (P2), a polymer compound (p20) having both a structural unit (u0) containing a phenolic hydroxyl group and a structural unit (u1) containing an acid-decomposable group whose polarity increases by the action of an acid is employed. By having both the developer solubility of the component (p10) having the structural unit (a0) and the resolution of the component (p20) having the structural unit (u1), it has a resolution capable of forming a fine pattern without residue even on a stepped substrate. The dissolution rate (DR MIX ) of such a mixed resin of the component (p10) and the component (p20) is smaller than the dissolution rate (DR P1 ) of the component (p10) and smaller than the dissolution rate (DR P2 ) of the component (p20). The reason for this is not clear, but for example, due to the steric hindrance caused by the hydrogen bond between the -COOH part of the structural unit (a0) of the component (p10) which is an alkali-soluble site and the -OH part of the structural unit (u0) containing a phenolic hydroxyl group of the component (p20) which is an alkali-soluble site, the neutralization reaction with the alkali component in the alkali developer proceeds with difficulty, resulting in a lower solubility as a mixed resin. From this, by using such a component (p10) and component (p20) as a mixed resin, the solubility of the mixed resin in the alkali developer can be lowered. Thereby, while suppressing the reduction of the developed film in the unexposed portion of the resist film, it has a resolution capable of forming a fine pattern without residue even on a stepped substrate.

[0345] In this embodiment, as a preferred combination of mixed resins, a resist composition having a first resin component (P1) and a second resin component (P2) with a specific dissolution rate relationship (i.e., DR MIX <DR P1 , and DR MIX <DR P2 ) is adopted. That is, a resin combination is selected in which the dissolution rate of the mixed resin in an alkaline developer is smaller than the dissolution rates of the individual resins in the alkaline developer. Thereby, the difference in solubility (dissolution contrast) of the resist film between the unexposed portion and the exposed portion in the developer can be made larger. In addition, film loss in the unexposed portion of the resist film is suppressed, and residues in the exposed portion of the resist film are less likely to occur. Furthermore, a resist pattern with higher sensitivity and higher resolution can be formed.

[0346] The resist pattern forming method of this embodiment can form a resist pattern with a good shape with less residue in the exposed portion of the resist film even when a copper substrate that is particularly likely to cause trailing and residues is used.

[0347] <Method for manufacturing a resist composition> The method for manufacturing a resist composition of this embodiment is a method for manufacturing a resist composition that generates an acid upon exposure and whose solubility in an alkaline developer increases due to the action of the acid, and includes a step of mixing a first resin component (P1) and a second resin component (P2). The first resin component (P1) includes a polymer compound (p10) having a structural unit (a0) derived from acrylic acid in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and the second resin component (P2) includes a polymer compound (p20) having a structural unit (u0) containing a phenolic hydroxyl group and a structural unit (u1) containing an acid-decomposable group whose polarity increases due to the action of an acid. As a preferred combination of the first resin component (P1) and the second resin component (P2), the dissolution rate of the first resin component (P1) in an alkaline developer is DR P1, the dissolution rate of the second resin component (P2) in an alkaline developer is DR P2 , the dissolution rate of the mixed resin of the first resin component (P1) and the second resin component (P2) in an alkaline developer is DR MIX When it is MIX <DR P1 , and DR MIX <DR P2 , there is a mixing ratio that satisfies this condition, and examples of the combination of the first resin component (P1) and the second resin component (P2) are given.

[0348] Regarding the (P1) component, the (P2) component, and the resist composition containing these, the description is the same as that of the <resist composition> described above. The mixing of the (P1) component and the (P2) component can be carried out by a known method, and if necessary, it may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill. The dissolution rates of the (P1) component, the (P2) component, and their mixed resin in an alkaline developer are controlled by appropriately selecting the type of raw material monomer of each resin, the combination or mixing ratio of the (P1) component and the (P2) component, etc.

Examples

[0349] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0350] <Resin component> In this example, the following polymer compounds were used respectively.

[0351] ≪(P1) component: Polymer compound (p10)≫ p10-1 to p10-5: Acrylic resins having structural units derived from the following monomers (m1) to (m7) in the unit ratios shown in Table 1

[0352]

Chemical formula

[0353]

Table 1

[0354] ≪(P2) Component: Polymer Compound (p20)≫ p20-1: A resin having 35 mol% of a structural unit in which an ethoxyethyl group is introduced as an acid dissociable group into polyhydroxystyrene (weight average molecular weight 10,000)

[0355] p20-2: A resin having 26 mol% of a structural unit in which a t-Boc group is introduced as an acid dissociable group into polyhydroxystyrene (weight average molecular weight 10,000)

[0356] p20-3: A resin having a unit ratio (molar ratio) of 60:15:25 of hydroxystyrene, styrene, and t-butyl acrylate, with a weight average molecular weight of 11,000

[0357] p20-4: A resin having a unit ratio (molar ratio) of 70:5:25 of hydroxystyrene, styrene, and t-butyl acrylate, with a weight average molecular weight of 11,000

[0358] p20-5: A resin having a unit ratio (molar ratio) of 60:25:15 of hydroxystyrene, styrene, and t-butyl acrylate, with a weight average molecular weight of 9,000

[0359] ≪(P3) Component: Polymer Compound (p30)≫ p30-1: A novolak resin obtained by subjecting a reaction product obtained by addition condensation of a mixture of m-cresol and p-cresol (m-cresol / p-cresol = 60 / 40 molar ratio) and formaldehyde in the presence of an acid catalyst to fractional separation with water + methanol to have a weight average molecular weight of 16,000 - 17,000

[0360] p30-2: A copolymer having a unit ratio (molar ratio) of 85:15 of hydroxystyrene and styrene, with a weight average molecular weight of 2,500

[0361] Copolymer having a weight average molecular weight of 2500 and having a unit ratio (molar ratio) of 75:25 of hydroxystyrene and styrene

[0362] <Measurement of dissolution rate of resin in alkaline developer> The dissolution rate of the resin (resin alone, mixed resin) in the alkaline developer was measured according to the following procedures (1') to (6'). Procedure (1'): Mix propylene glycol monomethyl ether acetate (PGMEA), 100 parts by mass of the resin, and 0.05 to 0.1 part by mass of a surfactant (BYK-310, manufactured by BYK) to prepare a resin solution having a resin concentration at which a resin film having a thickness of about 4 μm can be formed in the following film-forming step (procedure (2)). Procedure (2'): Spin-coat the resin solution on a silicon wafer, and then perform a film-forming heat treatment (PAB) at 120 °C for 120 seconds on a hot plate to form a resin film having a thickness of about 4 μm. Procedure (3'): Measure the film thickness (initial film thickness X) of the resin film using a film thickness measuring device (optical interference film thickness measuring device: NanoSpec Model 3000). Procedure (4'): Develop the silicon wafer on which the resin film is formed with an alkaline developer under the following development conditions.

[0363] Development conditions: Dip-develop the silicon wafer on which the resin film is formed with a 5 mass% TMAH aqueous solution at 23 °C. Procedure (5'): Measure the time (dissolution time Z) until the formed resin film is completely dissolved during Dip development.

[0364] Procedure (6'): Calculate the dissolution rate (DR) of the resin in the alkaline developer. DR (nm / s) = (X) / (Z)

[0365] [Measurement results of dissolution rate] The dissolution rate (DR) in the alkaline developer was measured for each of the polymer compound p20-3, other resins, and a mixed resin of the polymer compound p20-3 and other resins. These results are shown in Tables 2 and 3. As other resins, polymer compound p10-3, polymer compound p10-4, polymer compound p10-5, polymer compound p20-2, polymer compound p20-4, polymer compound p30-2, and polymer compound p30-3 were used. Both Table 2 and Table 3 show the dissolution rate (DR) when a 5 mass% TMAH aqueous solution is used as the developer.

[0366]

Table 2

[0367]

Table 3

[0368] From the results shown in Tables 2 to 3, in the combinations of polymer compound p20-3 and polymer compound p20-4, polymer compound p20-3 and polymer compound p20-2, polymer compound p20-3 and polymer compound p30-2, and polymer compound p20-3 and polymer compound p30-3, for each combination, the relationship between the dissolution rate (DR’ MIX ) of the mixed resin of each combination with respect to the alkaline developer, the dissolution rate (DR’ p20-3 ) of polymer compound p20-3 with respect to the alkaline developer, and the dissolution rate (DR’(other resins)) of each other resin alone with respect to the alkaline developer is DR’(other resins) < DR’ MIX < DR’ p20-3 , and it can be confirmed that this is the case.

[0369] Also, from the results shown in Tables 2 to 3, in the combinations of polymer compound p20-3 and polymer compound p10-1, polymer compound p20-3 and polymer compound p10-3, polymer compound p20-3 and polymer compound p10-4, and polymer compound p20-3 and polymer compound p10-5, it can be confirmed that the composition (mass ratio) of the mixed resin has a smaller dissolution rate in the alkaline developer than that of the individual resins (that is, it can be confirmed whether the composition has an effect of suppressing dissolution by mixing the resins).

[0370] <Formation of resist pattern> (Examples 1 to 19, Comparative Examples 1 to 34) In the formation of the resist pattern for each example, a resist composition (solid content concentration: 30% by mass) prepared by mixing and dissolving the respective components shown in Tables 4 to 12 in a propylene glycol monomethyl ether acetate (PGMEA) solvent was used respectively.

[0371]

Table 4

[0372]

Table 5

[0373]

Table 6

[0374]

Table 7

[0375]

Table 8

[0376]

Table 9

[0377]

Table 10

[0378]

Table 11

[0379]

Table 12

[0380] In Tables 4 to 12, each abbreviation has the following meaning. The numerical value in [ ] is the blending amount (parts by mass). (P1)-1: The above-mentioned polymer compound p10-1. (P1)-2: The above-mentioned polymer compound p10-2. (P1)-3: The above-mentioned polymer compound p10-3. (P1)-4: The above-mentioned polymer compound p10-4. (P1)-5: The above-mentioned polymer compound p10-5.

[0381] (P2)-1: The above-mentioned polymer compound p20-1. (P2)-2: The above-mentioned polymer compound p20-2. (P2)-3: The above-mentioned polymer compound p20-3. (P2)-4: The above-mentioned polymer compound p20-4. (P2)-5: The above-mentioned polymer compound p20-5.

[0382] (P3)-1: The above-mentioned polymer compound p30-1. (P3)-2: The above-mentioned polymer compound p30-2. (P3)-3: The above-mentioned polymer compound p30-3.

[0383] (B)-1: An acid generator composed of a compound represented by the following chemical formula (B-1). (F1)-1: Triamylamine. (F2)-1: Salicylic acid. (E)-1: Sulfur-containing compound represented by the following chemical formula (E-1). Add-1: Surfactant, BYK-310 (manufactured by BYK).

[0384] [Chemical formula]

[0385] Step of forming a resist film on a support: As an evaluation substrate, a silicon substrate treated with hexamethyldisilazane (HMDS) was used. Each resist composition prepared above was applied onto the silicon substrate using a spinner, and heated on a hot plate at a temperature of 120 °C for 120 seconds (post-applied (PAB) treatment), and dried to form a resist film with a thickness of 4 μm (4000 nm).

[0386] Step of exposing the resist film: Next, the resist film was selectively exposed through a mask pattern using an exposure apparatus Low NA i-Line stepper (FPA-5510iV, manufactured by Canon Inc.). Next, it was placed on a hot plate and subjected to post-exposure bake (PEB) treatment at 110 °C for 90 seconds.

[0387] Step of alkali-developing the exposed resist film: Next, using a developing apparatus (Clean Track ACT8, manufactured by Tokyo Electron Limited), an alkali development was performed for 60 seconds at 23 °C using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name "NMD-3", manufactured by Tokyo Ohka Kogyo Co., Ltd.).

[0388] [Measurement of film loss] The film thickness reduction (nm) was measured using a film thickness measuring device (optical interference film thickness measuring device: NanoSpec Model 3000) for the resist film thickness (initial film thickness X1) formed in the step of forming a resist film on the support. Next, the film thickness of the resist pattern (post-development film thickness Y1) after performing alkali development in the step of alkali-developing the resist film after exposure was measured using a film thickness measuring device (optical interference film thickness measuring device: NanoSpec Model 3000). Then, the film thickness reduction (nm) was calculated from the following formula. Film thickness reduction (nm) = (Initial film thickness X1) - (Post-development film thickness Y1)

[0389] [Measurement of dissolution rate (DR) in alkali developer] The dissolution rate (DR) (nm / s) in the alkali developer was calculated from the following formula. DR (nm / s) = Film thickness reduction (nm) / 60 (seconds)

[0390] [Measurement of 10μmEs] In the above <formation of resist pattern>, when the target size was a 1:1 space and line pattern with a space width of 10μm (hereinafter "SL pattern"), the exposure amount for pattern separation was confirmed. This was shown in a table as "10μmEs (mJ / cm 2 )".

[0391] [Measurement of 10μmEop] In the above <formation of resist pattern>, when the target size was a 1:1 space and line pattern with a space width of 10μm (hereinafter "SL pattern"), the exposure amount at which the pattern was formed almost as large as the mask size was confirmed. This was shown in a table as "10μmEop (mJ / cm 2 )".

[0392] [Evaluation of Reso at 10μmEop] In the above <formation of resist pattern>, when the target size was a 1:1 space and line pattern (hereinafter referred to as "SL pattern") with a space width of 10 μm, the exposure amount (10 μm Eop) at which the pattern was formed almost as large as the mask size was used to check up to what mask size the pattern was resolved separately. This was shown in a table as "Reso (nm) at 10 μm Eop".

[0393] [Evaluation of separate resolution] In the above <formation of resist pattern>, the location where the finest mask was resolved separately was checked by changing the exposure amount. This was shown in a table as "separate resolution (μm)".

[0394] [Calculation of (Eop - Es) / Eop] Using the values of 10 μm Eop and 10 μm Es obtained above, (Eop - Es) / Eop was calculated. The closer the value of "(Eop - Es) / Eop" is to 1, the more margin there is for residue, that is, it means that the residue is reduced.

[0395] This is presumably due to the fact that in the case of residue affected by the step of the substrate or the like, the exposure amount was insufficient in the exposure environment at the residue portion, resulting in a decrease in the solubility of the resist in the alkaline developer at the residue portion. Therefore, by improving the resist resolution on the lower exposure amount side than Eop, the residue caused by the low exposure at the residue portion can be reduced. Thus, by obtaining "(Eop - Es) / Eop", a simple evaluation of the residue margin becomes possible.

[0396] The results of film thickness reduction (nm), dissolution rate (DR) in the alkaline developer, 10 μm Es, 10 μm Eop, Reso at 10 μm Eop, separate resolution, and (Eop - Es) / Eop obtained in the resist pattern formation method of each example were shown in Tables 13 to 21.

[0397]

Table 13

[0398]

Table 14

[0399]

Table 15

[0400]

Table 16

[0401]

Table 17

[0402]

Table 18

[0403] From the results shown in Tables 13 to 18, it can be seen that the resist pattern forming method of the examples to which the present invention is applied suppresses the reduction of the development film, has high sensitivity, and is less likely to generate residues, as compared with the resist pattern forming methods of the corresponding comparative examples.

[0404]

Table 19

[0405] From the results shown in Table 19, it can be confirmed that when a mixed resin of the polymer compound p20-3 and the polymer compound p10-3 is employed in the resist composition, a high sensitivity can be achieved, the resolution can be enhanced, and residues are less likely to be generated, in the range where the mass ratio represented by p10-3 / p20-3 is p10-3 / p20-3 = 1 / 9 to 5 / 5.

[0406]

Table 20

[0407] From the results shown in Table 20, in the resist composition, when a mixed resin of polymer compound p20-3 and polymer compound p10-5 is employed, it can be confirmed that when the mass ratio represented by p10-5 / p20-3 is in the range of p10-5 / p20-3 = 1 / 9 to 4 / 6, high sensitivity can be achieved, the resolution can be enhanced, and residues are less likely to occur.

[0408] [Table 21]

[0409] From the results shown in Table 21, in the resist composition, when a mixed resin of polymer compound p20-3 and polymer compound p20-4 is employed, it was confirmed that there is no residue margin and the effect of reducing residues is not obtained.

Claims

1. A step of forming a resist film on a support using a resist composition that generates an acid upon exposure and whose solubility in an alkaline developer increases due to the action of the acid, A step of exposing the resist film, and A resist pattern forming method having a step of alkali-developing the exposed resist film to form a positive resist pattern, wherein the resist composition contains a first resin component (P1) and a second resin component (P2), the first resin component (P1) is a polymer compound (p10) having a structural unit (a0) represented by the following general formula (a0-0) (however, excluding those having a structural unit represented by the following general formula (u0-0)), the second resin component (P2) is a structural unit (u0) represented by the following general formula (u0-0) and a structural unit (u1) derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent and which contains an acid-decomposable group whose polarity increases due to the action of an acid, and is a polymer compound (p20) having both (however, excluding those having a structural unit represented by the following general formula (a0-0)), When the dissolution rate of the first resin component (P1) in the alkaline developer is DR P1, the dissolution rate of the second resin component (P2) in the alkaline developer is DR P2, and the dissolution rate of the mixed resin of the first resin component (P1) and the second resin component (P2) in the alkaline developer is DR MIX, DR MIX < DR P1 and DR MIX < DR P2 A resist pattern forming method in which the first resin component (P1) and the second resin component (P2) are used in combination at a mixing ratio that satisfies the above conditions. [Chemical Formula 1] [In the formula, R 0 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] [Chemical Formula 2] [In the formula, R22 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va22 is a divalent linking group or a single bond. Wa22 is an (na22 + 1)-valent aromatic hydrocarbon group. na22 is an integer of 1 to 3.]

2. The ratio of the constitutional unit (u1) in the polymer compound (p20) is 5 to 50 mol% with respect to the total (100 mol%) of all the constitutional units constituting the polymer compound (p20). The resist pattern forming method according to claim 1.

3. The ratio of the constitutional unit (a0) in the polymer compound (p10) is 5 to 40 mol% with respect to the total (100 mol%) of all the constitutional units constituting the polymer compound (p10). The resist pattern forming method according to claim 1 or 2.

4. The content ratio of the first resin component (P1) contained in the resist composition is 10 parts by mass or more and 50 parts by mass or less with respect to a total of 100 parts by mass of the first resin component (P1) and the second resin component (P2). The resist pattern forming method according to any one of claims 1 to 3.

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