Resist composition, resist pattern formation method, polymer compound, and fluorine additive component

Abstract

The present invention provides a resist composition, a resist pattern formation method, a polymer compound, and a fluorine additive component that reduce environmental impact and simultaneously suppress WMD (Wet Microwave Deposition) and Blob defects, which are necessary in TC-Less processes. [Solution] A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising a base component (A) whose solubility in a developer changes due to the action of the acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine additive component (F), wherein the fluorine additive component (F) comprises a polymer compound (F1) having a constituent unit (f1) represented by the general formula (f1-1) described in the specification and a constituent unit (fa1) represented by the general formula (fa-1) described in the specification, and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group.

Description

[Technical Field]

[0001] The present invention relates to a resist composition, a resist pattern formation method, a polymer compound, and a fluorine additive component. [Background technology]

[0002] In lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a developing process is performed to form a resist pattern of a predetermined shape on the resist film. A resist material in which the exposed area of ​​the resist film changes its properties to dissolve in the developing solution is called a positive type, and a resist material in which the exposed area changes its properties to not dissolve in the developing solution is called a negative type.

[0003] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization techniques involve shortening the wavelength (increasing the energy) of the exposure light source. Specifically, while ultraviolet light, such as the g-line and i-line, was conventionally used, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers has now begun. Furthermore, even shorter wavelengths (higher energy) than these excimer lasers, such as EUV (extreme ultraviolet), EB (electron beam), and X-rays, are also being investigated. In this situation, resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources or energy sources, and resolution that can reproduce patterns of fine dimensions.

[0004] One technique for further improving resolution is lithography, also known as liquid immersion lithography (hereinafter sometimes referred to as liquid immersion exposure), which involves placing a liquid with a higher refractive index than air (immersion medium) between the objective lens of the exposure machine and the sample during exposure (immersion exposure). Immersion lithography is said to achieve high resolution comparable to that achieved with shorter wavelength light sources or high NA lenses, even when using the same exposure wavelength light source, without any reduction in depth of field. Furthermore, immersion lithography can be performed using existing exposure equipment. Therefore, immersion lithography is expected to enable the formation of resist patterns that are low-cost, high-resolution, and have excellent depth of field, and is attracting considerable attention as it will have a significant impact on the semiconductor industry, both in terms of cost and lithography characteristics such as resolution, in the manufacturing of semiconductor devices, which currently require large capital investments. Immersion lithography is effective for forming all kinds of pattern shapes and can also be combined with super-resolution techniques such as phase-shift and deformation illumination, which are currently under investigation. Currently, immersion lithography techniques using ArF excimer lasers as the light source are being actively researched. Also, water is currently being considered as the main immersion medium.

[0005] Furthermore, in processes that use a topcoat-less (TC-less) resist film, which is advantageous for cost reduction in immersion lithography, the resist film is susceptible to the properties of the resist film surface (hydrophilicity, hydrophobicity, etc.). For example, by increasing the hydrophobicity of the resist film surface, material elution is reduced, and lithography characteristics are improved. In such resist compositions, it has been proposed to add compounds containing fluorine atoms (Patent Documents 1-4). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 5386236 [Patent Document 2] Japanese Patent Publication No. 2010-275498 [Patent Document 3] Patent No. 5569402 [Patent Document 4] Patent No. 5713011 [Overview of the project] [Problems that the invention aims to solve]

[0007] As lithography technology continues to advance and resist patterns become increasingly miniaturized, resist compositions require excellent lithographic properties. To obtain good lithographic properties, it is necessary to appropriately adjust the solubility and water repellency during development. Furthermore, due to the growing environmental awareness in recent years, the manufacture and use of compounds classified as PFAS (Per- and Polyfluoroalkyl Substances) may be restricted. Therefore, there is a need for the development of organofluorine compounds that do not contain perfluoroalkyl groups, perfluoroalkylene groups, or other perfluoroalkyl skeletons, nor difluoromethyl groups. However, when a resist pattern was formed using a compound that does not contain either a perfluoroalkyl skeleton or a difluoromethyl group as a fluorine additive component, it was difficult to achieve sufficient water repellency and base degradability, and water droplets tended to remain on the wafer surface after immersion exposure. Therefore, conventional resist compositions were unable to suppress the occurrence of water mark defects (WMDs). Furthermore, because hydrophilization during development was insufficient, components such as resin precipitated and adhered to the highly hydrophobic resist pattern surface, resulting in blob defects (Blob Defects).

[0008] The present invention has been made in view of the above circumstances, and aims to provide a resist composition, a resist pattern formation method, a polymer compound, and a fluorine additive component that can form a resist pattern that reduces environmental impact and achieves both the suppression of WMDs and the suppression of blob defects necessary in the TC-Less process. [Means for solving the problem]

[0009] As a result of diligent research to solve the above problems, the present inventors have found that a resist composition, a resist pattern formation method, a polymer compound, and a fluorine additive component can be obtained with the following configuration, which can form a resist pattern that reduces environmental impact and achieves both the suppression of WMD and the suppression of Blob defects necessary in the TC-Less process, and have completed the present invention.

[0010] In other words, the present invention is as follows: A resist composition according to the first embodiment of the present invention is a resist composition that generates acid upon exposure, and whose solubility in a developer changes due to the action of the acid, It contains a base component (A) whose solubility in the developer solution changes due to the action of acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine additive component (F). The aforementioned fluorine additive component (F) comprises a constituent unit (f1) represented by the following general formula (f1-1), The compound contains a polymer compound (F1) having a constituent unit (fa1) represented by the following general formula (fa-1), and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group.

[0011] [ka]

[0012] [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf is a divalent linking group. Ar is an aryl group. nf1 is an integer greater than or equal to 1.

[0013] [ka]

[0014] [In general formula (fa-1), R 01Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. 01 n is a divalent hydrocarbon group which may have an ether bond. f01 Rfa is an integer between 0 and 2. 01 This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

[0015] A resist pattern formation method according to a second embodiment of the present invention is a resist pattern formation method comprising the steps of forming a resist film on a support using a resist composition according to an embodiment of the present invention, exposing the resist film, and developing the resist film to form a resist pattern.

[0016] The polymer compound according to the third embodiment of the present invention comprises a constituent unit (f1) represented by the following general formula (f1-1), It has a constituent unit (fa1) represented by the following general formula (fa-1), This polymer compound does not contain any compounds having a perfluoroalkyl skeleton or any compounds having a difluoromethyl group.

[0017] [ka]

[0018] [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf is a divalent linking group. Ar is an aryl group. nf1 is an integer greater than or equal to 1.

[0019] [ka]

[0020] [In general formula (fa-1), R 01Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. 01 n is a divalent hydrocarbon group which may have an ether bond. f01 Rfa is an integer between 0 and 2. 01 This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

[0021] Furthermore, the fluorine additive component according to the fourth embodiment of the present invention comprises a constituent unit (f1) represented by the above general formula (f1-1), It contains a polymer compound having a constituent unit (fa1) represented by the above general formula (fa-1), and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. [Effects of the Invention]

[0022] The present invention can provide a resist composition, a resist pattern formation method, a polymer compound, and a fluorine additive component that reduce environmental impact and simultaneously suppress WMD (Wet Mass Deposition) and Blob defects, which are necessary in TC-Less processes. [Brief explanation of the drawing]

[0023] [Figure 1] Figure 1 illustrates the forward angle (θ1), backward angle (θ2), and backward angle (θ3). [Modes for carrying out the invention]

[0024] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below.

[0025] In this disclosure, "aliphatic" is defined as a concept relative to aromatic, meaning groups, compounds, etc., that do not possess aromaticity. "Alkyl group" shall include linear, branched, and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified. The same applies to the alkyl group in an alkoxy group. "Alkylene group" shall include linear, branched, and cyclic divalent saturated hydrocarbon groups, unless otherwise specified. "Halogenated alkyl group" is 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 atoms include fluorine atom, chlorine atom, bromine atom, and 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. "Structural unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer). When described as "may have a substituent", 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.

[0026] "Structural unit derived from an acrylate ester" means a structural unit formed by cleavage of the ethylenic double bond of an acrylate ester. "Acrylate ester" is a compound in which the hydrogen atom at the carboxyl group terminal of acrylic acid (CH2=CH-COOH) is substituted with an organic group. In the acrylate ester, the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R α0 ) 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. Further, the acrylate ester is an itaconic acid diester in which the substituent (R α0 ) is substituted with a substituent containing an ester bond, and the substituent (R α0This also includes α-hydroxyacrylic esters in which the α group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group thereof. Unless otherwise specified, the α-carbon atom of the acrylic acid ester refers to the carbon atom to which the carbonyl group of the acrylic acid ester is bonded. Hereinafter, acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom is replaced by a substituent are sometimes called α-substituted acrylic acid esters. Also, acrylic acid esters and α-substituted acrylic acid esters are sometimes collectively referred to as "(α-substituted) acrylic acid esters."

[0027] "Constituent units derived from hydroxystyrene" refers to constituent units formed by the cleavage of the ethylenic double bond of hydroxystyrene. "Constituent units derived from hydroxystyrene derivatives" refers to constituent units formed by the cleavage of the ethylenic double bond of a hydroxystyrene derivative. The term "hydroxystyrene derivative" refers to a compound in which the α-hydrogen atom of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of hydroxystyrene, which may have its α-hydrogen atom substituted with a substituent, is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the benzene ring of hydroxystyrene, which may have its α-hydrogen atom substituted with a substituent. Unless otherwise specified, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded. Examples of substituents that substitute the hydrogen atom at the α-position of hydroxystyrene include those similar to those listed as substituents at the α-position in the α-substituted acrylic acid esters.

[0028] "Constituent units derived from vinylbenzoic acid or vinylbenzoic acid derivatives" means constituent units formed by the cleavage of the ethylenic double bond of vinylbenzoic acid or vinylbenzoic acid derivatives. The term "vinyl benzoic acid derivative" refers to a concept that includes vinyl benzoic acid in which the α-position hydrogen atom is substituted with other substituents such as alkyl groups and alkyl halides, as well as derivatives thereof. Examples of such derivatives include vinyl benzoic acid in which the hydrogen atom of the carboxyl group, which may have the α-position hydrogen atom substituted with a substituent, is substituted with an organic group; and vinyl benzoic acid in which substituents other than hydroxyl groups and carboxyl groups are bonded to the benzene ring, which may have the α-position hydrogen atom substituted with a substituent. Unless otherwise specified, the α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded.

[0029] The alkyl group used as the substituent at the α-position is preferably a linear or branched alkyl group. 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.). Furthermore, the halogenated alkyl group as the α-substituent specifically refers to a group in which some or all of the hydrogen atoms of the "alkyl group as the α-substituent" described above are replaced with halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., with fluorine atoms being particularly preferred. Furthermore, the hydroxyalkyl group as the α-substituent specifically refers to a group in which some or all of the hydrogen atoms of the "alkyl group as the α-substituent" described above are replaced with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, with 1 being the most preferred.

[0030] In this disclosure, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. Furthermore, in this disclosure, the amount of each component in a composition means the total amount of multiple substances corresponding to each component present in the composition, unless otherwise specified. Furthermore, the chemical structural formulas in this disclosure may also be described as simplified structural formulas in which hydrogen atoms are omitted. In this disclosure, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers or diastereomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture. In this disclosure, "mass%" and "weight%" are synonymous, and "parts of mass" and "parts of weight" are synonymous.

[0031] [Resist composition] The resist composition according to an embodiment of the present invention is a resist composition that generates acid upon exposure, and whose solubility in a developer changes due to the action of the acid, It contains a base component (A) whose solubility in the developer solution changes due to the action of acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine additive component (F). The aforementioned fluorine additive component (F) consists of a constituent unit (f1) represented by the general formula (f1-1) described later, It contains a polymer compound (F1) having a constituent unit (fa1) represented by the general formula (fa-1) described below, and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. It is a resist composition.

[0032] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, acid is generated in the exposed areas of the resist film. The solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0033] In this disclosure, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition. The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process that uses an alkaline developer for the development process during resist pattern formation, or it may be for a solvent development process that uses a developer containing an organic solvent (organic developer) for the development process. In other words, the resist composition of this embodiment is a "positive-type resist composition for alkaline development processes" that forms a positive-type resist pattern in an alkaline development process, and a "negative-type resist composition for solvent development processes" that forms a negative-type resist pattern in a solvent development process.

[0034] The resist composition of this embodiment is a resist composition that generates acid upon exposure and whose solubility in a developer solution changes due to the action of the acid, and contains a base component (A) whose solubility in a developer solution changes due to the action of the acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine-containing additive component (F) that includes a polymer compound (F1) having a constituent unit (f1) represented by the general formula (f1-1) and a constituent unit (fa1) represented by the general formula (fa-1).

[0035] Component (A) may generate acid upon exposure, in which case component (A) becomes a "substrate component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid." When component (A) is a substrate component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid, it is preferable that component (A1), described later, is a polymer compound that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid. As such a polymer compound, a copolymer having a constituent unit that generates acid upon exposure can be used. Examples of constituent units that generate acid upon exposure include known ones.

[0036] In conventional resist compositions, fluorine-containing compounds commonly used as fluorine additives cause problems such as segregation on the surface of the resist pattern, resulting in a deterioration of the rectangular shape of the pattern. Furthermore, from an environmental perspective, there is a desire to reduce the use of organofluorine compounds that fall under PFAS (Protein-Fragrant Aquatic Substances). However, removing fluorine from fluorine-containing compounds results in extremely low surface segregation and water repellency.

[0037] The fluorine additive component (F) according to the embodiment of the present invention includes a polymer compound (F1) having a constituent unit (f1) represented by general formula (f1-1) and a constituent unit (fa1) represented by general formula (fa-1). Furthermore, since the fluorine additive component (F) does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group, it is possible to reduce the environmental burden and achieve both the suppression of WMD and the suppression of Blob defects, which are necessary in the TC-Less process.

[0038] (A) Ingredients In the resist composition of this embodiment, component (A) is a base component whose solubility in the developer solution changes due to the action of an acid, and component (A) preferably includes a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in the developer solution changes due to the action of an acid. Component (A) may be one whose solubility in the developer increases with the action of the acid, or it may be one whose solubility in the developer decreases with the action of the acid. By using component (A1), the polarity of the substrate component (A) changes before and after exposure, so that good development contrast can be obtained not only in the alkaline development process but also in the solvent development process. (A) The component used is at least component (A1), and other high-molecular-weight compounds and / or low-molecular-weight compounds may be used in combination with component (A1).

[0039] When an alkaline development process is applied, the substrate component (A) containing component (A1) is poorly soluble in the alkaline developer before exposure. When acid is generated from component (B) upon exposure, the polarity of the substrate component (A) increases due to the action of the acid, and its solubility in the alkaline developer increases. Therefore, when a resist film obtained by coating the resist composition onto a support is selectively exposed during the formation of a resist pattern, the exposed parts of the resist film change from poorly soluble to soluble in the alkaline developer, while the unexposed parts of the resist film remain poorly soluble in the alkali. Thus, a positive-type resist pattern is formed by alkaline development.

[0040] On the other hand, when a solvent development process is applied, the substrate component (A) containing component (A1) is highly soluble in organic developer before exposure. When acid is generated from component (B) upon exposure, the polarity of the substrate component (A) increases due to the action of the acid, and its solubility in organic developer decreases. Therefore, when selectively exposing the resist film obtained by coating the resist composition onto a support during the formation of a resist pattern, the exposed parts of the resist film change from soluble to poorly soluble in organic developer, while the unexposed parts of the resist film remain soluble. Thus, by developing with an organic developer, a contrast can be created between the exposed and unexposed parts, and a negative-type resist pattern is formed.

[0041] (A) Component is preferably a polymer compound (A1) having a constituent unit (a1) that contains an acid-degradable group whose polarity increases due to the action of an acid (hereinafter also referred to as "component (A1)"). (A1) It is preferable to use a polymer compound having a structural unit (a2) that includes a lactone-containing cyclic group, an -SO2--containing cyclic group, or a carbonate-containing cyclic group in addition to the structural unit (a1).

[0042] In the resist composition according to an embodiment of the present invention, component (A) may be used alone or in combination of two or more types.

[0043] Component (A) preferably does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group, and is preferably a polymer compound that does not fall under the category of PFAS. In other words, component (A1) is preferably a compound that does not fall under the category of PFAS. If component (A) contains other components other than component (A1), it is preferable that the other components are also compounds that do not fall under the category of PFAS.

[0044] <Constituent unit (a1)> The constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases upon the action of an acid. An "acid-degradable group" is a group that has acid-degradability, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases upon the action of an acid include groups that decompose upon the action of an acid to produce polar groups. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO3H). Among these, polar groups containing -OH in their structure (hereinafter sometimes referred to as "OH-containing polar groups") are preferred, carboxyl groups or hydroxyl groups are more preferred, and carboxyl groups are particularly preferred. More specifically, examples of acid-degradable groups include groups in which the aforementioned polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group). Here, "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, further causing the bond between the acid-dissociable group and an adjacent atom to be cleaved. The acid-dissociable group constituting the acid-degradable group must be less polar than the polar group generated by its dissociation. This means that when the acid-dissociable group dissociates due to the action of acid, a polar group with higher polarity is generated, increasing the polarity. As a result, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0045] The constituent unit (a1) preferably contains an acid-degradable group having an alicyclic hydrocarbon group, and more preferably contains an acid-degradable group having a monocyclic alicyclic hydrocarbon group. In the constituent unit (a1), if the acid-degradable group (acid-dissociable group) has an alicyclic hydrocarbon group, its bulkiness is appropriate, allowing for appropriate control of acid diffusion and solubility in the developer, thereby reducing roughness when forming the resist pattern. Examples of acid-dissociable groups in the constituent unit (a1) include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resists. Specifically, proposed acid-dissociable groups for base resins used in chemically amplified resist compositions include "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0046] Acetal type acid dissociable group: Examples of acid-dissociable groups that protect a carboxyl group or a hydroxyl group among the aforementioned polar groups include the acid-dissociable group represented by the following formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0047] [ka]

[0048] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 Ra' is a hydrocarbon group. 3 Ra' 1 , Ra' 2 It may combine with any of the following to form a ring.

[0049] In formula (a1-r-1), Ra' 1 and Ra' 2 Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. Ra' 1 Or Ra' 2 If the alkyl group is an alkyl group, the alkyl group can be the same as those listed in the description of the α-substituted acrylic acid ester above as substituents that may be bonded to the carbon atom at the α position, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl group or ethyl group being more preferred, and methyl group being particularly preferred.

[0050] In formula (a1-r-1), Ra' 3 Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0051] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0052] Ra' 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0053] Ra' 3 When the cyclic hydrocarbon group becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' 3 Specific examples of aromatic hydrocarbon groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0054] Ra' 3 The cyclic hydrocarbon group in may have substituents. Examples of substituents include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (These substituents are collectively referred to as "Ra" below) 05 It is also called "[...]." Examples include [...]. Here, R P1This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 This is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above substituents individually, or may have one or more of the above substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups with 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0055] Ra' 3 However, Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0056] Tertiary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2). Furthermore, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may, for convenience, be referred to below as "tertiary alkyl ester type acid-dissociable groups."

[0057] [ka]

[0058] [In the formula, Ra' 4 ~Ra' 6 Each of these represents a hydrocarbon group, Ra' 5 , Ra' 6 They may be joined to each other to form a ring.

[0059] Ra' 4 Examples of hydrocarbon groups represented by include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. Ra' 4 In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups) are defined as Ra' 3 Examples include linear or branched alkyl groups and cyclic hydrocarbon groups similar to those found in [the relevant context]. Ra' 4 The linear or cyclic alkenyl group in this is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group is the aforementioned Ra' 3 Examples include those similar to the hydrocarbon group shown.

[0060] Ra' 5 and Ra' 6When these groups bond to each other to form a ring, the acid-dissociable group represented by the above formula (a1-r-2) is preferably the group represented by the following formula (a1-r2-1), the group represented by the following formula (a1-r2-2), or the group represented by the following formula (a1-r2-3). Meanwhile, Ra' 4 ~Ra' 6 When these are independent hydrocarbon groups that are not bonded to each other, the group represented by the following formula (a1-r2-4) is preferred as the acid-dissociable group represented by the above formula (a1-r-2).

[0061] [ka]

[0062] [In formula (a1-r2-1), Ra 031 This represents an alkyl group, and Yab 0 Xab represents a carbon atom. 0 Yab 0 Ra represents a group that forms an alicyclic hydrocarbon group together with Ya, and some or all of the hydrogen atoms in this alicyclic hydrocarbon group may be substituted. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. 101 ~Ra 103 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' 12 and Ra' 13Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. 14 This is a hydrocarbon group that may have substituents. * indicates a bond.

[0063] In the above equation (a1-r2-1), Ra 031 The alkyl group is preferably a linear alkyl group having 1 to 12 carbon atoms, and may be partially substituted with halogen atoms or heteroatom-containing groups.

[0064] Ra 031 In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra 031 In this, the branched alkyl group is the Ra' 4 Similar examples include the above.

[0065] Ra 031 In this case, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms used here include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0066] In formula (a1-r2-1), Xab 0 Yab 0 The alicyclic hydrocarbon group formed together is Ra' in the above formula (a1-r-1). 3A group obtained by further removing one or more hydrogen atoms from the aliphatic hydrocarbon group (alicyclic hydrocarbon group) listed as a monocyclic or polycyclic group is preferred. Among these, a monocyclic alicyclic hydrocarbon group is more preferred, and a group obtained by removing two or more hydrogen atoms from a monocycloalkane is even more preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specifically includes cyclopentane, cyclohexane, cycloheptane, cyclooctane, etc.

[0067] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Ra' in formula (a1-r-2). 4 Examples include groups obtained by further removing one or more hydrogen atoms from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group). The cyclic hydrocarbon group formed by Xa and Ya may have substituents. Examples of such substituents include the above-mentioned Ra' 4 Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in the above. In formula (a1-r2-2), Ra 101 ~Ra 103 Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Ra 101 ~Ra 103 Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Ra 101 ~Ra 103Among them, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0068] The above Ra 101 ~Ra 103 Examples of the substituent of the linear saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by include, for example, the same groups as those of Ra 05 mentioned above.

[0069] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of Ra

[0070] forming a cyclic structure by bonding to each other include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group, and the like. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferable. 4 In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is preferably a group obtained by further removing one or more hydrogen atoms from the group cited as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra' In formula (a1-r2-3), examples of the aromatic hydrocarbon group for Ra 104 include a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0071] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed include, for example, a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), an alkyloxycarbonyl group, and the like.

[0072] In formula (a1-r2-4), Ra’ 12 and Ra’ 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Ra’ 12 and Ra’ 13 Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in include the same as those of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 101 ~Ra 103 Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 Among them, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable. In the above Ra’ 12 and Ra’ 13 When the linear saturated hydrocarbon group represented by is substituted, examples of the substituent include, for example, the same groups as those of the above Ra 05

[0073] In formula (a1-r2-4), Ra’ 14 is a hydrocarbon group that may have a substituent. Examples of the hydrocarbon group in Ra’ 14 include a linear or branched alkyl group or a cyclic hydrocarbon group.

[0074] Ra’ 14 ​The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0075] Ra' 14 The branched alkyl group in the compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and so on, with isopropyl group being preferred.

[0076] Ra' 14 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, and the like.

[0077] Ra' 14 As for aromatic hydrocarbon groups in this context, Ra 104 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' 14The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from naphthalene or anthracene with one or more hydrogen atoms removed; and most preferably a group from naphthalene with one or more hydrogen atoms removed. Ra' 14 A substituent that may be present is Ra 104 Examples of substituents that may be present include those similar to those that the molecule may have.

[0078] Ra' in equation (a1-r2-4) 14 If is a naphthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. Ra' in equation (a1-r2-4) 14 If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0079] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0084] [Chemical]

[0085] [Chemical]

[0086] [Chemical]

[0087] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0088] [Chemical]

[0089] Specific examples of the group represented by the formula (a1-r2-4) are given below.

[0090] [Chemical]

[0091] · Tertiary alkyloxycarbonyl acid dissociable group: As the acid dissociable group for protecting the hydroxyl group among the polar groups, for example, the acid dissociable group represented by the following formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkyloxycarbonyl acid dissociable group" for convenience) can be mentioned.

[0092] [Chemical]

[0093] [In the formula, Ra’ 7 ~Ra’ 9 each represents an alkyl group.]

[0094] In the formula (a1-r-3), Ra’ 7 ~Ra’ 9Each of these is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0095] As for the acid-dissociable group, among the groups represented by the general formulas (a1-r2-1) to (a1-r2-4) above, the group represented by general formula (a1-r2-1) or (a1-r2-4) above is preferred.

[0096] Specifically, the constituent unit (a1) can be described by the following general formula (a1-1).

[0097] (Constituent unit (a1) represented by general formula (a1-1)) In the resist composition according to the embodiment of the present invention, the base component (A) preferably contains a polymer compound (A1) having a constituent unit (a1) represented by the following general formula (a1-1).

[0098] [ka]

[0099] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 1 n is a divalent hydrocarbon group which may have an ether bond. a1 is an integer between 0 and 2. 1 This represents an acid-dissociable group.

[0100] In formula (a1-1), 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, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. 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 halogen atoms include fluorine, chlorine, bromine, and iodine atoms. R is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group due to their industrial availability.

[0101] In the above formula (a1-1), Va 1 The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Va 1 The aliphatic hydrocarbon group as a divalent hydrocarbon group in this compound may be saturated or unsaturated, but is usually preferred to be saturated. More specifically, examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0102] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0103] Examples of aliphatic hydrocarbon groups containing a ring in the aforementioned structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a monocycloalkane from which two hydrogen atoms have been removed. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a polycycloalkane from which two hydrogen atoms have been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0104] Va 1 In this context, an aromatic hydrocarbon group as a divalent hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings in aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in an arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. In the above formula (a1-1), Ra 1 represents an acid-dissociable group. Examples of acid-dissociable groups include those listed above, preferably an acid-dissociable group represented by the above formulas (a1-r2-1) to (a1-r2-4), and more preferably an acid-dissociable group represented by the above formulas (a1-r2-1) or (a1-r2-4).

[0105] In the above formula (a1-1), n a1 n is an integer between 0 and 2. a1 The value is preferably 0 or 1, and more preferably 0.

[0106] The formula (a1-1) is preferably the following formula (a1-2).

[0107]

Chemical formula

[0108] (In the general formula (a1-2), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 3 represents a divalent hydrocarbon group which may have an ether bond. na3 represents an integer of 0 to 2. Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom.) Xab 0 is a group that forms an alicyclic hydrocarbon group together with Yab 0 , and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.)

[0109] In the general formula (a1-2), R and Va 3 are the same as R and Va 1 in the formula (a1-1), respectively.)

[0110] In the general formula (a1-2), na3 is an integer of 0 to 2, preferably 0 or 1, and more preferably 0.)

[0111] In the general formula (a1-2), Ra 031 , Xab 0 , Yab 0 are the same as Ra 031 , Xab 0 , Yab 0 in the formula (a1-r2-1), respectively.)

[0112] In the general formula (a1-2), Ra 031 is preferably a chain alkyl group among the above, preferably a monovalent chain alkyl group having 1 to 3 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group or an iso-propyl group is more preferable.)

[0113] The following are specific examples of constituent units (a1). In the following formula, R α This represents a hydrogen atom or a methyl group.

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] (A1) The constituent units (a1) that the component may have may be one type or two or more types. In component (A1), the proportion of constituent unit (a1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a1) to above the lower limit of the preferred range described above, lithography characteristics such as increased sensitivity, improved resolution, and reduced roughness are enhanced. Conversely, by setting it below the upper limit, a balance can be achieved with other constituent units, resulting in good lithography characteristics across various fields. Furthermore, in the resist composition according to the embodiment of the present invention, the constituent unit (a1) may not contain an acetal-type acid-dissociable group.

[0125] <Constituent unit (a2)> Component (A1) may further have a constituent unit (a2) containing a lactone-containing cyclic group, an -SO2-- containing cyclic group, or a carbonate-containing cyclic group (excluding those corresponding to constituent unit (a1)). The lactone-containing cyclic group, -SO2--containing cyclic group, or carbonate-containing cyclic group of the constituent unit (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1) is used to form a resist film. Furthermore, the presence of constituent unit (a2) improves lithography characteristics, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0126] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- within its cyclic skeleton. Counting the lactone ring as the first ring, a group consisting only of a lactone ring is called a monocyclic group, while a group with other ring structures, regardless of its structure, is called a polycyclic group. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0127] [ka]

[0128] [In general formulas (a2-r-1) to (a2-r-7), Ra' 21 Each of the following 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 (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2, and m' is 0 or 1. * indicates a bond.

[0129] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, pentyl group, iso-pentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' 21The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' 21 Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Ra' 21 Examples of halogen atoms in this context include fluorine, chlorine, bromine, and iodine atoms. Ra' 21 The halogenated alkyl group in is the Ra' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.

[0130] Ra' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.

[0131] When R'' is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R'' is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0132] Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above. The carbonate-containing cyclic groups in R'' are the same as those described later, and specifically include the groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively. The -SO2-containing cyclic groups in R'' are the same as those described later, and specifically include the groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively.

[0133] Ra' 21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' 21 Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0134] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above, the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, or isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, or -CH2-S-CH2-. A'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0135] The following are specific examples of the groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0136] [ka]

[0137] [ka]

[0138] A "-SO2-containing cyclic group" refers to a cyclic group that contains a ring with -SO2- in its cyclic skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the cyclic skeleton. The ring containing -SO2- in its cyclic skeleton is counted as the first ring. If it consists only of this ring, it is called a monocyclic group. If it has other ring structures, it is called a polycyclic group regardless of those structures. A -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2--containing cyclic group is preferably a cyclic group that contains -O-SO2- in its cyclic skeleton, that is, a cyclic group that contains a sultone ring in which the -OS- in -O-SO2- forms part of the cyclic skeleton. More specifically, examples of -SO2- containing cyclic groups include the groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0139] [ka]

[0140] [In general formulas (a5-r-1) to (a5-r-4), Ra' 51 Each of the following 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, and n' is an integer from 0 to 2.

[0141] In the general formulas (a5-r-1) to (a5-r-2) above, A'' is the same as A'' in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above. Ra' 51In this context, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formula (a2-r-1) to (a2-r-7). 21 The same things mentioned in the explanation about this topic can be cited. Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] A "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- within its cyclic framework. The carbonate ring is counted as the first ring. If it consists only of a carbonate ring, it is called a monocyclic group. If it also has other ring structures, it is called a polycyclic group regardless of those structures. A carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. Any carbonate ring-containing cyclic group can be used without any particular limitations. Specifically, examples include the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

[0146] [ka]

[0147] [In the formula, Ra' x31Each of the following 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, where p' is an integer from 0 to 3, and q' is 0 or 1. * indicates a bond.

[0148] In the above general formulas (ax3-r-2) to (ax3-r-3), A'' is the same as A'' in the above general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra' X31 In this context, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formula (a2-r-1) to (a2-r-7). 21 The same things mentioned in the explanation about this topic can be cited. The following are specific examples of groups represented by the general formulas (ax3-r-1) to (ax3-r-3).

[0149] [ka]

[0150] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. The constituent unit (a2) is preferably a constituent unit represented by the following general formula (a2-1).

[0151] [ka]

[0152] [In general formula (a2-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 21 It is a single bond or a divalent linking group. 21 The R' is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La 21 If -O-, Ya 21 It does not become -CO-. 21 This is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group.

[0153] In formula (a2-1), R is the same as R in formula (a1-1). R is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0154] In the above formula (a2-1), Ya 21 The divalent linking group in this is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0155] • Divalent hydrocarbon groups which may have substituents: Ya 21 If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0156] ··Ya 21 Aliphatic hydrocarbon groups in An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferable to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0157] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0158] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0159] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a monocycloalkane from which two hydrogen atoms have been removed. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a polycycloalkane from which two hydrogen atoms have been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0160] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, 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 preferred, and a methoxy group and an ethoxy group are even more preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0161] ··Ya 21 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an 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 in 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.

[0162] The aromatic hydrocarbon group may have its hydrogen atoms 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 such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0163] • Divalent linking groups containing heteroatoms: Ya 21When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - is represented by the base [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents independently, O is an oxygen atom, and m'' is an integer from 1 to 3.

[0164] When the divalent linking group containing the heteroatom is -C(=O)-NH-, -NH-, or -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5. Formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - Middle, Y 21 and Y 22Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the aforementioned Ya 21 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 21 Preferably, the group is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group.

[0165] Y 22 The group is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a 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. Formula - [Y 21 -C(=O)-O] m” -Y 22 In the base represented by -, m'' is an integer from 1 to 3, preferably 1 or 2, and more preferably 1. That is, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As a base represented by -, formula -Y 21 -C(=O)-OY 22 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0166] Among the above, Ya 21Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0167] In the above formula (a2-1), Ra 21 This is a lactone-containing cyclic group, an -SO2-- containing cyclic group, or a carbonate-containing cyclic group. Ra 21 In this context, suitable examples of lactone-containing cyclic groups, -SO2--containing cyclic groups, and carbonate-containing cyclic groups include the groups represented by the general formulas (a2-r-1) to (a2-r-7), (a5-r-1) to (a5-r-4), and (ax3-r-1) to (ax3-r-3), respectively.

[0168] In the above formula (a2-1), Ra 21 Among the above, lactone-containing cyclic groups or -SO2--containing cyclic groups are preferred, groups represented by the general formulas (a2-r-1), (a2-r-2), (a2-r-6), or (a5-r-1) are more preferred, and groups represented by the general formulas (a2-r-1) or (a2-r-2) are even more preferred. Specifically, the groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), and (r-lc-6-1) are preferred, and the groups represented by the chemical formulas (r-lc-1-1), (r-lc-2-1), or (r-lc-2-12) are even more preferred.

[0169] The constituent units (a2) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a2), the proportion of constituent units (a2) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a2) is set above a preferred lower limit, the effects of including constituent unit (a2) are fully obtained due to the effects described above, and if it is below the upper limit, a balance can be achieved with other constituent units, resulting in good lithography characteristics.

[0170] <Other constituent units> Component (A1) may have other constituent units other than the constituent units (a1) and (a2) described above. Other constituent units include, for example, constituent units containing polar group-containing aliphatic hydrocarbon groups (a3); constituent units containing acid-nondissociable aliphatic cyclic groups (a4); and constituent units derived from styrene or styrene derivatives (st). Many of the constituent units containing polar group-containing aliphatic hydrocarbon groups (a3), constituent units containing acid-nondissociable aliphatic cyclic groups (a4); and constituent units derived from styrene or styrene derivatives (st) that are conventionally known to be used as resin components in resist compositions can be used.

[0171] Such component (A1) can be produced by dissolving monomers that induce each constituent unit in a polymerization solvent and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the mixture and polymerizing it. Alternatively, such component (A1) can be produced by dissolving a monomer that induces constituent unit (a1) and a monomer that induces constituent unit (a2) in a polymerization solvent, and then adding the above-mentioned radical polymerization initiator to carry out polymerization.

[0172] In the resist composition according to the embodiment of the present invention, the weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is preferably 4,000 or more, more preferably 5,000 or more, even more preferably 6,000 or more, and even more preferably 6,500 or more. The Mw of component (A1) is preferably 30,000 or less, more preferably 20,000 or less, and even more preferably 12,000 or less. In the resist composition according to the embodiment of the present invention, the Mw of component (A1) is preferably 4,000 to 120,000, more preferably 5,000 to 30,000, and even more preferably 6,000 to 20,000. If the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the preferred lower limit of this range, it has good dry etching resistance, LWR (linewise roughness), and LER.

[0173] The dispersion of component (A1) (Mw / Mn) is not particularly limited, but is preferably 1.0 or higher, preferably 4.0 or lower, more preferably 3.0 or lower, and particularly preferably 2.0 or lower. The dispersion of component (A1) (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0174] Regarding base components other than component (A1): In the embodiment of the present invention, the resist composition may also include, as component (A), a base component that does not correspond to component (A1) and whose solubility in the developer changes due to the action of an acid (hereinafter referred to as "component (A2)"). (A2) The component is not particularly limited and can be arbitrarily selected from a large number of components that have been conventionally known as base components for chemically amplified resist compositions. (A2) Component may be a single high-molecular-weight compound or a low-molecular-weight compound, or two or more may be used in combination.

[0175] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, it is easier to form a resist pattern that is excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement. The proportion of component (A1) in component (A) is not particularly limited, but for example it can be 100% by mass or less.

[0176] In the resist composition according to the embodiment of the present invention, the content of component (A) can be adjusted according to the resist film thickness to be formed, and is not particularly limited, but is preferably 2% by mass or more, and more preferably 3% by mass or more, based on the total mass (100% by mass) of the resist composition. The upper limit of the content of component (A) is not particularly limited as long as it is at a concentration that can form a resist film, but for example, is preferably 10% by mass or less, and more preferably 5% by mass or less.

[0177] ≪Acid Generating Agent Component (B)≫ The resist composition according to the embodiment of the present invention further contains, in addition to the above-described component (A) and component (F) described below, an acid generating agent component (B) (hereinafter referred to as "component (B)") that generates acid upon exposure. (B) The component is not particularly limited, and any acid generators previously proposed 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; oximesulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, among many others. Component (B) preferably contains a compound consisting of an onium salt, and more preferably contains a compound (B1) represented by the following general formula (b-01) (hereinafter sometimes referred to as "component (B1)").

[0178] [ka]

[0179] [In general formula (b-01), Rf 01 and Rf 02 Each of these independently represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group, and Rf 01 , Rf 02 It contains a fluorine atom in at least one of them. X represents a divalent linking group. Y represents an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. m represents an integer greater than or equal to 1, and M m+ This represents an m-valent organic cation.

[0180] [Anion Club (YXC(Rf 01 )(Rf 02 )-SO3 - )] In general formula (b-01), YXC(Rf 01 )(Rf 02 )-SO3 - This is a counter anion. The counter anion is not particularly limited, and those proposed as the anionic portion of acid generators for chemically amplified resist compositions can be used.

[0181] In general formula (b-01), Rf 01 and Rf 02 Each of these independently represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group.

[0182] Rf 01 and Rf 02 The fluorinated alkyl groups represented by may be linear or cyclic, and are preferably linear or branched. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4.

[0183] Specifically, examples include groups in which some or all of the hydrogen atoms constituting a linear alkyl group such as a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, or decyl group are substituted with fluorine atoms, and groups in which some or all of the hydrogen atoms constituting a branched alkyl group such as a 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, or 3-methylbutyl group are substituted with fluorine atoms. Also, Rf 01 and Rf 02 Each of the fluorinated alkyl groups represented by may independently contain atoms other than fluorine, carbon, and hydrogen atoms, such as oxygen, sulfur, or nitrogen atoms. Among them, Rf 01 and Rf 02 The fluorinated alkyl group represented by is preferably a group in which some or all of the hydrogen atoms constituting a linear alkyl group are substituted with fluorine atoms, and preferably a group in which all of the hydrogen atoms constituting a linear alkyl group are substituted with fluorine atoms (perfluoroalkyl group).

[0184] In general formula (b-01), Rf 01 and Rf 02 Preferably, each of these represents a fluorine atom.

[0185] In general formula (b-01), X represents a divalent linking group, and it is preferable that it is a divalent linking group containing an oxygen atom. If X is a divalent linking group containing an oxygen atom, X may also contain atoms other than oxygen. Examples of atoms other than oxygen include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, and so on.

[0186] Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7). In the following general formulas (y-al-1) to (y-al-7), the Y in the above general formula (b-01) is bonded to V' in the following general formulas (y-al-1) to (y-al-7). 101 That is the case.

[0187] [ka]

[0188] [In the formula, V' 101 V' is a single bond or an alkylene group with 1 to 5 carbon atoms. 102 It is a divalent saturated hydrocarbon group with 1 to 30 carbon atoms.

[0189] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0190] V ’101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V ’101 and V' 102Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, V ’101 or V' 102 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 Ra' in formula (a1-r-1). 3 A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0191] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably a linking group represented by any of the above formulas (y-al-1) to (y-al-5).

[0192] In general formula (b-01), Y represents an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. Cyclic groups which may have substituents: The cyclic group in Y, which may have substituents, is preferably a cyclic hydrocarbon group, and this cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0193] The aromatic hydrocarbon group in Y is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings in the aromatic hydrocarbon group Y include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Specific examples of aromatic hydrocarbon groups in Y include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, and 2-naphthylethyl groups). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0194] The cyclic aliphatic hydrocarbon group in Y includes aliphatic hydrocarbon groups that contain a ring in their structure. The cyclic aliphatic hydrocarbon group in Y preferably has 3 to 50 carbon atoms, preferably 4 to 45 carbon atoms, and more preferably 5 to 40 carbon atoms. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. 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 a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane; polycycloalkanes having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0195] In particular, as the cyclic aliphatic hydrocarbon group in Y, a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane is preferred, a group obtained by removing one hydrogen atom from a polycycloalkane is more preferred, an adamantyl group and a norbornyl group are even more preferred, and an adamantyl group is particularly preferred.

[0196] The following are some preferred examples of cyclic aliphatic hydrocarbon groups in Y. * indicates a bond.

[0197] [ka]

[0198] The linear aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. Examples of linear aliphatic hydrocarbon groups include linear alkylene groups, specifically methylene groups [-CH2-], ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6, even more preferably 3 or 4, and most preferably 3. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0199] Furthermore, the cyclic hydrocarbon group in Y may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In the formulas, * represents a bond attached to X in general formula (b-01).

[0200] [ka]

[0201] Examples of substituents on the cyclic group of Y include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. As alkyl groups used as substituents, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, 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 preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine, chlorine, bromine, and iodine atoms, with fluorine being preferred. Examples of alkyl halides used as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. A carbonyl group as a substituent is a group that substitutes for a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0202] The cyclic hydrocarbon group in Y may be a fused ring group containing a fused ring formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridging ring system with one or more aromatic rings fused to it. Specific examples of the bridging ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to a bicycloalkane, and more preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to bicyclo[2.2.2]octane. Specific examples of the fused ring group in Y include the groups represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents a bond that connects to X in the general formula (b-01).

[0203] [ka]

[0204] Examples of substituents that the fused ring group in Y may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides used as substituents on the fused cyclic group are the same as those listed as substituents on the cyclic group in Y above. Examples of aromatic hydrocarbon groups as substituents on the fused ring group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, 2-naphthylethyl groups, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of alicyclic hydrocarbon groups as substituents on the fused cyclic group include: groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4); and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16).

[0205] The cyclic hydrocarbon group in Y may be a group linked by two or more aliphatic rings and / or aromatic rings which may have substituents, either linear or branched aliphatic hydrocarbon group. The linear or branched aliphatic hydrocarbon group linking the alicyclic hydrocarbon group may have methylene groups (-CH2-) constituting the aliphatic hydrocarbon chain substituted with a divalent group containing a heteroatom. Examples of divalent groups containing a heteroatom include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0206] Chain-like alkyl groups which may have substituents: The linear alkyl group in Y may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. Specifically, examples include 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, henicosyl group, docosyl group, and the like. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. 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, and 4-methylpentyl group.

[0207] A chain-like alkenyl group which may have substituents: The linear alkenyl group in Y may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0208] Examples of substituents in the linear alkyl or alkenyl group in Y include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R. 101 Examples include cyclic groups in this context.

[0209] Among the above, Y is preferably a chain-like alkyl group which may have substituents, or an alicyclic hydrocarbon group which may have substituents, more preferably a chain-like alkyl group which may have halogen atoms, a group obtained by removing one or more hydrogen atoms from a polycycloalkane which may have substituents, or an -SO2-containing cyclic group represented by any of the general formulas (a5-r-1) to (a5-r-4), even more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane which may have substituents, or an -SO2-containing cyclic group represented by any of the general formulas (a5-r-1) to (a5-r-4), and particularly preferably an adamantyl group which may have a hydroxyl group or an -SO2-containing cyclic group represented by the general formula (a5-r-1).

[0210] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably a linking group represented by any of the above formulas (y-al-1) to (y-al-5), and even more preferably a linking group represented by the above formulas (y-al-1) or (y-al-3).

[0211] Specific examples of the anion part represented by general formula (b-01) include, for example, when X is a divalent linking group containing an oxygen atom, the anions represented by the following formulas (an-1) to (an-3) can be cited.

[0212] [ka]

[0213] [In the formula, R” 101 R” is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by any of the above chemical formulas (r-hr-1) to (r-hr-16), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), or an optionally substituted linear alkyl group. 102R” is an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by any of the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or a -SO2-containing cyclic group represented by any of the general formulas (a5-r-1) to (a5-r-4). 103 V” is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. 101 This is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 [wherein 'v' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; where 'v' is an independent integer from 0 to 3, where 'q' is an independent integer from 0 to 20, and where 'n' is 0 or 1.]

[0214] R" 101 , R” 102 and R” 103 The aliphatic cyclic group which may have substituents is preferably the group exemplified as the cyclic aliphatic hydrocarbon group in Y in the general formula (b-01). Examples of substituents are the same as substituents which may substitute for the cyclic aliphatic hydrocarbon group in Y in the general formula (b-01).

[0215] R" 103 The aromatic cyclic group in which substituents may be present is preferably one of the groups exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in Y in the general formula (b-01). Examples of substituents include those similar to those that may substitute for the aromatic hydrocarbon group in Y in the general formula (b-01).

[0216] R" 101 The optionally substituted linear alkyl group in the above general formula (b-01) is preferably one of the groups exemplified as the linear alkyl group in Y. R" 103The substituted linear alkenyl group in is preferably one of the groups exemplified as the linear alkenyl group in Y in the general formula (b-01).

[0217] Among the anions in the above general formula (b-01), an anion represented by any of the above general formulas (an-1) to (an-3) is more preferred, an anion represented by either general formula (an-1) or (an-2) is even more preferred, and an anion represented by general formula (an-1) is particularly preferred.

[0218] Specific examples of anions represented by general formula (b-01) are shown below, but are not limited to these.

[0219] [ka]

[0220] [ka]

[0221] [Cation part: (M m+ ) 1 / m ] In the general formula (b-01), M m+ This represents an m-valent organic cation. M m+ In this compound, onium cations are preferred as the organic cation, sulfonium cations, iodonium cations, and ammonium cations are more preferred, and sulfonium cations and iodonium cations are even more preferred. m is an integer of 1 or more.

[0222] Preferred cation portion ((M m+ ) 1 / m Examples of organic cations include those represented by any of the following general formulas (ca-1) to (ca-3).

[0223] [ka]

[0224] [In general formulas (ca-1) to (ca-3), R 201 ~R 207 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group, and R 201 ~R 203 , R 206 ~R 207 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 210 L is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 This represents -C(=O)- or -C(=O)-O-.

[0225] R 201 ~R 207 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 201 ~R 207 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, arylthio groups, and groups represented by any of the following formulas (ca-r-1) to (ca-r-7). Examples of aryl groups in the arylthio group as a substituent include aryl groups having 6 to 20 carbon atoms, with phenyl, naphthyl, and biphenyl groups being preferred. Examples of arylthio groups include phenylthio, naphthylthio, and biphenylthio groups.

[0226] [ka]

[0227] [In the formula, R' 201 Each of these is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0228] R' 201 The cyclic group which may have substituents represented by is preferably a cyclic hydrocarbon group, and this cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of aromatic hydrocarbon groups include aromatic hydrocarbon rings, or aryl groups obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings, with phenyl groups and naphthyl groups being preferred. Examples of aliphatic hydrocarbon groups include monocycloalkanes or polycycloalkanes from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being preferred.

[0229] R' 201 The linear alkyl group, which may have substituents represented by , can be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. Specifically, examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henicosyl group, docosyl group, and the like.

[0230] R' 201 The linear alkenyl group, which may have substituents represented by , may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. As for the linear alkenyl group, Examples include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylpropenyl groups and 2-methylpropenyl groups. Among the above, the propenyl group is particularly preferred as the chain-like alkenyl group.

[0231] R' 201 Examples of optionally substituted cyclic groups or optionally substituted linear alkyl groups represented by include those similar to the acid-dissociable groups described above.

[0232] R' 201 Examples of substituents on the cyclic group, linear alkyl group, or linear alkenyl group represented by include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. The alkyl group used as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, 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 preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine, chlorine, bromine, and iodine atoms, with fluorine being preferred. Examples of alkyl halides used as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms.

[0233] R 201 ~R 203 , R 206 ~R 207 When these atoms bond to each other and form a ring with the sulfur atom in the formula, they may be heteroatoms such as sulfur, oxygen, or nitrogen atoms, or carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring is preferably a 3 to 10-membered ring, and particularly preferably a 5 to 7-membered ring, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, thiazole ring, benzothiophene ring, thianthlene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthlene ring, phenoxatiyne ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring, thioxanium ring, and the like.

[0234] R 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, with a hydrogen atom or an alkyl group having 1 to 3 carbon atoms being preferred. 208 ~R 209 However, if each element independently becomes an alkyl group, they may bond to each other to form a ring.

[0235] R 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 210 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 210 In the context of -SO2-containing cyclic groups which may have substituents, "-SO2-containing cyclic group" refers to a cyclic group that contains a ring with -SO2- in its cyclic skeleton, specifically a cyclic group in which the sulfur atom (S) in -SO2- forms part of the cyclic skeleton. The ring containing -SO2- in its cyclic skeleton is counted as the first ring, and if it consists only of this ring, it is called a monocyclic group; if it has other ring structures, it is called a polycyclic group regardless of those structures. -SO2-containing cyclic groups may be monocyclic or polycyclic. The -SO2--containing cyclic group is preferably a cyclic group that contains -O-SO2- in its cyclic skeleton, that is, a cyclic group that contains a sultone ring in which the -OS- in -O-SO2- forms part of the cyclic skeleton. R 210 In this context, the -SO2-containing cyclic group which may have substituents is preferably the group represented by the above formula (a5-r-1). R 210 The substituents that may be present are the aforementioned R 201 ~R 207 Examples of substituents that may be present include:

[0236] The cation represented by formula (ca-1) is preferably the cation represented by the following formula (b-2).

[0237] [ka]

[0238] [In formula (b-2), Rb 201 ~Rb 202 Each of these represents an aryl group which may have substituents, and Rb 203 Rb represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~Rb 203 These atoms may bond to each other to form a ring with the sulfur atom in formula (b-2).

[0239] Rb 201 ~Rb 202 The aryl group which may have substituents represented by the above R 201 ~R 207 This is synonymous with an aryl group which may have substituents, and the preferred examples are similar. Rb 203 The optionally substituted aryl group, optionally substituted alkyl group, or optionally substituted alkenyl group represented by the above R 201 ~R 207 This is synonymous with an aryl group which may have substituents, an alkyl group which may have substituents, or an alkenyl group which may have substituents, and the preferred examples are similar.

[0240] Suitable cations represented by formula (ca-1) include, specifically, cations represented by any of the following formulas (ca-1-1) to (ca-1-67).

[0241] [ka]

[0242] [ka]

[0243] [ka]

[0244] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 1 to 20.]

[0245] [ka]

[0246] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the aforementioned R 201 ~R 207 , and R 210 These are the same as those listed as substituents that may be present.

[0247] Specific examples of suitable cations represented by the above formula (ca-3) include cations represented by any of the following formulas (ca-3-1) to (ca-3-6).

[0248] [ka]

[0249] In the resist composition according to the embodiment of the present invention, component (B1) may be used alone or in combination of two or more types.

[0250] In the resist composition according to the embodiment of the present invention, the content of component (B1) is preferably 1 to 60 parts by mass, more preferably 2.5 to 50 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of component (A). (B1) When the proportion of component B1 is above the preferred lower limit, lithography characteristics such as roughness reduction and increased sensitivity are further improved. On the other hand, when it is below the upper limit, it becomes easier to form a resist pattern with excellent exposure latitude.

[0251] • About ingredient (B2) The resist composition according to the embodiment of the present invention may contain an acid generating agent component other than component (B1) (hereinafter referred to as "component (B2)"), to the extent that it does not impair the effects of the present invention. The (B2) component is not particularly limited, and any acid generators previously proposed 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; oximesulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, among many others.

[0252] In the resist composition according to the embodiment of the present invention, component (B2) may be used alone or in combination of two or more types. If the resist composition contains component (B2), the content of component (B2) in the resist composition is preferably 30 parts by mass or less, and more preferably 1 to 25 parts by mass, per 100 parts by mass of component (A). By setting the content of component (B2) in the resist composition within the above range, sufficient pattern formation is achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable as it results in good storage stability for the resist composition.

[0253] In the resist composition according to the embodiment of the present invention, the content of the acid generator component (B) is preferably 1 to 40 parts by mass, more preferably 2.5 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, per 100 parts by mass of the base component (A). By setting the content of the acid generator component (B) in the resist composition within the above range, it becomes easier to obtain a resist composition with excellent temporal stability, and to form a resist pattern that achieves both high exposure latitude and high sensitivity to the exposure light source.

[0254] (F) Ingredient: Fluoride additive ingredient The resist composition in this embodiment contains the fluorine additive component in this embodiment (hereinafter referred to as "component (F)"). Component (F) is used to impart water repellency to the resist film, and by being used as a hydrophobic resin separate from component (A), the ability to segregate to the upper layer of the film by fluorine atoms and water repellency are obtained. Component (F) contains a polymer compound (F1) having a constituent unit (f1) represented by the following general formula (f1-1) and a constituent unit (fa1) represented by the following general formula (fa-1), and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. In this embodiment, component (F1) in the resist composition is a copolymer of a structural unit (f1) having a fluorine atom in an aryl group and a structural unit (fa1), wherein structural unit (fa1) is a monocyclic protecting group with 8 or more carbon atoms in the detached portion (i.e., the acid-dissociable group) of the acid-degradable group. Therefore, it is considered that the precipitation of components such as the base resin dissolved in the alkaline developer solution and the occurrence of Blob defects, etc., due to the action of base decomposition, particularly in the alkaline development process when rinsing with water after development, can be suitably suppressed.

[0255] As described above, the resist composition in this embodiment includes a polymer compound (F1) as component (F), which has a constituent unit (f1) represented by the following general formula (f1-1) and a constituent unit (fa1) represented by the following general formula (fa-1). Furthermore, the polymer compound (F1) does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. This reduces the environmental impact and enables both the suppression of WMD and the suppression of Blob defects, which are necessary in the TC-Less process.

[0256] <Constituent unit (f1)> The constituent unit (f1), represented by the general formula (f1-1), has a fluorine atom in its aryl group, and therefore exhibits excellent segregation ability to the upper layer of the resist film due to the action of the fluorine atom. As a result, the resist film formed by the resist composition in this embodiment exhibits high water repellency, which has the effect of suppressing residual water on the wafer and suppressing the elution of the resist composition during immersion lithography. Furthermore, since the constituent unit (f1) does not contain either a perfluoroalkyl skeleton or a difluoromethyl group, it can reduce the environmental impact.

[0257] [ka]

[0258] [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf1 is a divalent linking group. Ar is an aryl group. nf1 is an integer greater than or equal to 1.

[0259] As stated above, the general formula (f1-1) does not contain either a perfluoroalkyl skeleton or a difluoromethyl group.

[0260] In the general formula (f1-1), the alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. A 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 halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, with a hydrogen atom or a methyl group being the most preferred due to their industrial availability.

[0261] Lf1 is a divalent linking group, and Ya of the general formula (a2-1) 21 The same examples mentioned in the explanation of the divalent linking group in [the relevant context] can be cited. As Lf1, a divalent linking group containing a heteroatom is preferred, such as -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-[C(=O)-O] m” -Y 21 -C(=O)-OY 22 -,-[C(=O)-O] m” -Y 22 -C(=O)-O-, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 A group represented by - is even more preferred, -[C(=O)-O] m” -Y 21 -C(=O)-OY 22 - is particularly preferred [in the formula, Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents, O is an oxygen atom, and m'' is an integer from 1 to 3.

[0262] Examples of aryl groups represented by Ar include aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, anthracenyl, and phenanthryl groups, with phenyl being preferred. Ar has nf1 fluorine atoms as substituents, and may further have substituents other than fluorine atoms. Examples of such substituents include groups represented by alkyl groups, halogen atoms other than fluorine atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, arylthio groups, hydroxyl groups, and nitro groups.

[0263] nf1 is an integer greater than or equal to 1, preferably a number that can substitute all the hydrogen atoms on the aryl group represented by Ar.

[0264] In the constituent unit (f1), the above general formula (f1-1) is preferably represented by the following general formula (f1-2).

[0265] [ka]

[0266] [In the general formula (f1-2), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. nf3 is either 1 or 2. Lf2 is a divalent linking group. Rf1 is a substituted linear hydrocarbon group, a substituted cyclic hydrocarbon group, a nitro group, or a cyano group. Ar is an aryl group. nf2 is an integer greater than or equal to 2.

[0267] nf3 is either 1 or 2, and is preferably 1.

[0268] Lf2 is a divalent linking group, and Ya of the general formula (a2-1) 21 The same examples mentioned in the explanation of the divalent linking group in [the relevant context] can be cited. As Lf2, a divalent linking group containing a heteroatom is preferred, such as -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 A group represented by - is even more preferred, -Y 21 -C(=O)-O- is particularly preferred [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents, O is an oxygen atom, and m'' is an integer from 1 to 3.

[0269] In general formula (f1-2), Rf1 is a chain hydrocarbon group which may have substituents, a cyclic hydrocarbon group which may have substituents, a nitro group, or a cyano group. Therefore, the decomposition reaction by abstraction of hydrogen fluoride (HF) caused by basic compounds occurs more readily, and sufficient basic decomposition properties are obtained. As a result, segregation of the fluorine additive component (F) on the resist pattern surface is eliminated, and it is presumed that a resist pattern with a good shape can be formed.

[0270] The chain-like hydrocarbon group represented by Rf1 can be a linear or branched alkyl group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0271] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0272] Examples of substituents that the chain-like hydrocarbon group in Rf1 may have include groups represented by a halogen atom, a carbonyl group, a cyano group, an amino group, an aryl group, an arylthio group, a hydroxyl group, or a nitro group, with a nitro group or a cyano group being preferred.

[0273] The cyclic hydrocarbon group represented by Rf1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0274] When the cyclic hydrocarbon group represented by Rf1 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specifically, examples of aromatic hydrocarbon groups represented by Rf1 include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0275] Examples of substituents that the cyclic hydrocarbon group in Rf1 may have include groups represented by a halogen atom, a carbonyl group, a cyano group, an amino group, an aryl group, an arylthio group, a hydroxyl group, or a nitro group.

[0276] Examples of aryl groups represented by Ar include aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, anthracenyl, and phenanthryl groups, with phenyl being preferred. Ar has nf2 fluorine atoms as substituents, and may further have substituents other than fluorine atoms. Examples of such substituents include groups represented by alkyl groups, halogen atoms other than fluorine atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, arylthio groups, hydroxyl groups, and nitro groups.

[0277] nf2 is an integer greater than or equal to 2, preferably a number that can substitute all the hydrogen atoms on the aryl group represented by Ar.

[0278] Specific examples of constituent units (f1) are given below. In the following formula, R a This represents a hydrogen atom or a methyl group.

[0279] [ka]

[0280] [ka]

[0281] [ka]

[0282] The constituent units (f1) of component (F1) may be one type or two or more types. The proportion of constituent units (f1) in component (F1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (F1). If the proportion of constituent unit (f1) is above a preferred lower limit, sufficient surface segregation and water-repellent effects can be obtained by including constituent unit (f1). If it is below the upper limit, a balance can be maintained with other constituent units, resulting in good blob defect characteristics.

[0283] <Constituent unit (fa1)> The polymer compound (F1) has, in addition to the constituent unit (f1) represented by the above general formula (f1-1), a further constituent unit (fa1) represented by the following general formula (fa-1).

[0284] [ka]

[0285] [In general formula (fa-1), R 01 Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. 01 n is a divalent hydrocarbon group which may have an ether bond. f01 Rfa is an integer between 0 and 2. 01 This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

[0286] The constituent unit (fa1) is a constituent unit containing an acid-degradable group with 8 or more carbon atoms, including a monocyclic hydrocarbon group. By increasing hydrophilicity through deprotection, it is possible to reduce Blob defects, and a resist composition can be provided that can achieve both the suppression of WMD required in the TC-Less process and the suppression of Blob defects.

[0287] R in general formula (fa-1) 01 , Vfa 01 , and n f01 These are R and Va in the general formula (a1-1) mentioned above, respectively. 1 , and n a1 It is similar to the above. However, the general formula (fa-1) does not contain either a perfluoroalkyl skeleton or a difluoromethyl group.

[0288] Rfa 01 Rfa is an acid-dissociable group containing a monocyclic hydrocarbon group and having 8 or more carbon atoms. 01 The monocyclic hydrocarbon group inside and the other linking groups and substituents together have a total of 8 or more carbon atoms, making them acid-dissociable groups. The monocyclic hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A monocyclic aromatic hydrocarbon group is a hydrocarbon group that has one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may even be a monocyclic system. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12.

[0289] Rfa 01 The acid-dissociable group represented by contains a monocyclic hydrocarbon group and has 8 or more carbon atoms, preferably an acid-dissociable group represented by any of the following formulas (fa1-r2-1) to (fa1-r2-4).

[0290] [ka]

[0291] [Formulas (fa1-r2-1) to (fa1-r2-4) are acid-dissociable groups with 8 or more carbon atoms. In formula (fa1-r2-1), Rfa 031 This represents an alkyl group, Yfab 0 This represents a carbon atom. (Xfab) 0 Yfab 0 It represents a group that forms a monocyclic alicyclic hydrocarbon group together with the other group, and some or all of the hydrogen atoms in this alicyclic hydrocarbon group may be substituted. In formula (fa1-r2-2), Yfa is a carbon atom. Xfa is a group that forms a monocyclic hydrocarbon group together with Yfa. Some or all of the hydrogen atoms in this monocyclic hydrocarbon group may be substituted. Rfa 101 ~Rfa 103Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. 101 ~Rfa 103 Two or more of these may be joined together to form a ring structure. In formula (fa1-r2-3), Yfaa is a carbon atom. Xfaa is a group that, together with Yfaa, forms a monocyclic aliphatic cyclic group. Rfa 104 This is an aromatic hydrocarbon group which may have substituents. In formula (fa1-r2-4), Rfa' 12 and Rfa' 13 Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Rfa' 14 This is a monocyclic hydrocarbon group which may have substituents. * indicates a bond.

[0292] In the above equation (fa1-r2-1), Rfa 031 This is Ra in the above formula (a1-r2-1). 031 It is similar to that.

[0293] In formula (fa1-r2-1), Xfab 0 (Yfab 0 The group that forms a monocyclic alicyclic hydrocarbon group together with the other group is a monocyclic alicyclic hydrocarbon group, for example, a group obtained by removing two or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 10 carbon atoms, more preferably one having 3 to 8 carbon atoms, and even more preferably one having 3 to 6 carbon atoms. Specifically, cyclopentane, cyclohexane, cycloheptane, and cyclooctane are suitable examples.

[0294] In formula (fa1-r2-2), the monocyclic hydrocarbon group formed by Xfa together with Yfa may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A monocyclic aromatic hydrocarbon group is a hydrocarbon group that has one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may even be a monocyclic system. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12.

[0295] A monocyclic aliphatic hydrocarbon group is preferred as the monocyclic hydrocarbon group that Xfa forms with Yfa.

[0296] The cyclic hydrocarbon group formed by Xfa together with Yfa may have substituents. Examples of such substituents include the above-mentioned Ra' 4 Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in the above.

[0297] In formula (fa1-r2-2), Rfa 101 ~Rfa 103 These are Ra in the above formula (a1-r2-2), respectively. 101 ~Ra 103 It is similar to that.

[0298] In formula (fa1-r2-3), the monocyclic aliphatic cyclic group formed by Xfaa together with Yfaa can be, for example, a group obtained by removing two or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 10 carbon atoms, more preferably one having 3 to 8 carbon atoms, even more preferably one having 3 to 6 carbon atoms. Specifically, cyclopentane, cyclohexane, cycloheptane, and cyclooctane are suitable examples. In formula (fa1-r2-3), Rfa 104 This is Ra in the above formula (a1-r2-3).104 It is similar to that.

[0299] In formula (fa1-r2-4), Rfa' 12 and Rfa' 13 These are Ra' in the above formula (a1-r2-4), respectively. 12 and Ra' 13 It is similar to that.

[0300] In formula (fa1-r2-4), Rfa' 14 This is a monocyclic hydrocarbon group, which may have substituents. Rfa' 14 The monocyclic hydrocarbon group in this expression may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, cycloheptane, and cyclooctane. A monocyclic aromatic hydrocarbon group is a hydrocarbon group that has one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may even be a monocyclic system. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12.

[0301] Rfa' 14 It is preferable that it is a monocyclic aliphatic hydrocarbon group.

[0302] Rfa' 14 A substituent that may be present is Ra in formula (a1-r2-3). 104 Examples of substituents that may be present include those similar to those that the molecule may have.

[0303] Furthermore, even if the substituents are the same as those described above, formulas (fa1-r2-1) to (fa1-r2-4) do not contain either a perfluoroalkyl skeleton or a difluoromethyl group.

[0304] Specific examples of the group represented by the formula (fa1-r2-1) are given below.

[0305] [ka]

[0306] [ka]

[0307] Specific examples of the group represented by the formula (fa1-r2-2) are given below.

[0308] [ka]

[0309] Specific examples of the group represented by the above formula (fa1-r2-3) are given below.

[0310] [ka]

[0311] Specific examples of the group represented by the formula (fa1-r2-4) are given below.

[0312] [ka]

[0313] The following are specific examples of constituent units (fa1). In the following formula, R α This represents a hydrogen atom or a methyl group.

[0314] [ka]

[0315] [ka]

[0316] [ka]

[0317] [ka]

[0318] [ka]

[0319] The constituent units (fa1) of the polymer compound (F1) may be one type or two or more types. In the polymer compound (F1), the proportion of constituent units (fa1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 15 to 40 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound (F1). By setting the proportion of the constituent unit (fa1) to above the lower limit of the preferred range described above, the Blob defect characteristics are improved. Furthermore, by setting it below the upper limit, the segregation of the fluorine additive is improved.

[0320] <Other constituent units> The polymer compound (F1) may have other constituent units besides the constituent unit (f1) represented by the general formula (f1-1) and the constituent unit (fa1) described above (excluding constituent units (f1), constituent unit (fa1), those having a perfluoroalkyl skeleton, and those having a difluoromethyl group). Examples of other constituent units include the constituent unit (a2) described above.

[0321] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If the weight-average molecular weight is below the upper limit of this range, the resist composition in this embodiment has sufficient solubility in resist solvents for use as a resist, and if the weight-average molecular weight is above the lower limit of this range, the resist composition in this embodiment has good dry etching resistance and a good resist pattern cross-sectional shape. The degree of dispersion of component (F) (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0322] As component (F), in addition to the polymer compound (F1) described above, for example, any fluorine-containing polymer compound described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 that does not contain any compounds having a perfluoroalkyl skeleton or any compounds having a difluoromethyl group can be used. Furthermore, in the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types.

[0323] If the resist composition contains component (F), the amount of component (F) is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 2 to 7 parts by mass, per 100 parts by mass of component (A).

[0324] <Optional ingredients> The resist composition of this embodiment may further contain components other than those described above (components (A), B, and F) (optional components). Examples of such optional components include the (D) component and the (S) component shown below.

[0325] It is preferable that components (D) and (S) do not contain compounds corresponding to PFAS. It is preferable that components (D) and (S) do not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. Furthermore, it is even more preferable that they do not contain fluorine atoms.

[0326] ≪Acid diffusion control component (D)≫ The resist composition according to the embodiment of the present invention may further contain an acid diffusion control component (D) in addition to components (A), (B), and (F). The acid diffusion control component (D) (component (D)) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Component (D) may be, for example, a photodegradable base (D1) that decomposes upon exposure and loses its acid diffusion control properties (hereinafter referred to as "component (D1)"), or a nitrogen-containing organic compound (D2) that does not fall under component (D1) (hereinafter referred to as "component (D2)"), but component (D1) is preferred. (D) By using a resist composition containing component D, the contrast between the exposed and unexposed areas of the resist film can be further improved when forming a resist pattern.

[0327] It is preferable that component (D) does not contain any compounds having a perfluoroalkyl skeleton or any compounds having a difluoromethyl group. It is preferable that component (D) contains only compounds that do not fall under the category of compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. In other words, it is preferable that component (D) does not contain any compounds that fall under the category of PFAS. Furthermore, it is preferable that component (D) does not contain any fluorine atoms.

[0328] • About the (D1) component By using a resist composition containing component (D1), the contrast between the exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. Component (D1) may be used as an acid generator in addition to or in place of component (B) above. The (D1) component is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, but it is preferable to select one or more compounds from the group consisting of compounds represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component") and compounds represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"). Components (d1-1) and (d1-2) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), and therefore do not act as quenchers, but they act as quenchers in the unexposed areas of the resist film.

[0329] [ka]

[0330] [In general formula (d1-1) and general formula (d1-2), Rd 1 and Rd 2 Each of these is independently an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group. However, Rd in formula (d1-2) 2 Assume that no fluorine atoms are bonded to carbon atoms adjacent to the S atom. m is an integer greater than or equal to 1, and M m+ These are each independently m-valent organic cations.

[0331] {(d1-1) component} · Anion Club In formula (d1-1), Rd 1 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of the above R' is... 201 Similar examples include the above. Among these, Rd 1Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Optional substituents on these groups include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups, ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and in this case, preferred substituents are linking groups represented by any of the above formulas (y-al-1) to (y-al-5).

[0332] Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane. The linear alkyl group is preferably one with 1 to 10 carbon atoms, and specifically includes linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0333] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and so on.

[0334] The following are some preferred specific examples of the anionic portion of component (d1-1).

[0335] [ka]

[0336] • Cation section In formula (d1-1), M m+ This is an m-valent organic cation. M m+ Suitable organic cations include those similar to the cations represented by any of the general formulas (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cation represented by any of the formulas (ca-1-1) to (ca-1-67) being even more preferred. (d1-1) Component may be used alone or in combination of two or more types.

[0337] {(d1-2) component} · Anion Club In formula (d1-2), Rd 2 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 201 Similar examples include the above. However, Rd 2 In this mixture, we assume that the carbon atom adjacent to the S atom is not bonded to a fluorine atom (i.e., not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd 2Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents. The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10. The aliphatic cyclic group preferably has one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc. (which may have substituents); more preferably has one or more hydrogen atoms removed from camphor, etc. Rd 2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). 1 Examples include substituents similar to those that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above.

[0338] The following are preferred specific examples of the anionic portion of component (d1-2).

[0339] [ka]

[0340] • Cation section In formula (d1-2), M m+ is an m-valent organic cation, and M in formula (d1-1) above. m+ It is similar to that. (d1-2) Components may be used individually or in combination of two or more.

[0341] Component (D1) may consist of only one of the above components (d1-1) to (d1-2), or it may consist of a combination of two or more components. If the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2.5 to 15 parts by mass, per 100 parts by mass of component (A). When the content of component (D1) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0342] (D1) Method for producing component: The methods for producing components (d1-1) and (d1-2) are not particularly limited and can be produced by known methods. For example, they can be produced in the same manner as described in U.S. Patent Publication 2012-0149916.

[0343] • About the (D2) component Component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under component (D1) above, as an acid diffusion control agent component. Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under component (D1), and any known component may be used. Among these, aliphatic amines or aromatic amines are preferred, and aromatic amines are more preferred.

[0344] An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic group has 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia (NH3) is substituted with an alkyl group having 12 or fewer carbon atoms or a hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0345] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Examples of aliphatic monocyclic amines include piperidine and piperazine. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred, and specifically, examples include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0346] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

[0347] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, trimenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0348] (D2) Component may be used alone or in combination of two or more types. When the resist composition contains component (D2), the content of component (D2) in the resist composition is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A). By using this range, the resist pattern shape, aging stability, etc., are improved.

[0349] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). The (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent that is conventionally known as a solvent for chemically amplified resist compositions can be appropriately selected and used. In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0350] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility between PGMEA and the polar solvent. Furthermore, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is set appropriately according to the coating thickness, at a concentration that can be applied to a substrate or the like. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0351] The resist composition in this embodiment may further optionally contain miscible additives, such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, and the like.

[0352] The resist composition of this embodiment contains the above-described components (A), (B), and (F), and optionally the aforementioned optional components. For example, a resist composition containing component (A), component (B), component (F), and component (D) is preferred. Furthermore, a resist composition containing component (A), component (B), component (F), component (D), and component (S) is preferred.

[0353] The resist composition preferably does not contain any compounds having a perfluoroalkyl skeleton or any compounds having a difluoromethyl group, and preferably does not contain any compounds corresponding to PFAS. The components contained in the resist composition preferably do not contain any compounds having a trifluoromethyl group, any compounds having a difluoromethyl group, and any compounds having a difluoromethylene group. Furthermore, it is more preferable that the resist composition does not contain any fluorine atoms.

[0354] The resist composition of this embodiment described above contains a base component (A) whose solubility in the developer solution changes due to the action of an acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine-containing additive component (F) that includes a polymer compound (F1) having a constituent unit (f1) represented by the general formula (f1-1) and a constituent unit (fa1) represented by the general formula (fa-1). Component (F) is bulky because Rf1 represents a specific group, thus providing sufficient base decomposition properties. Furthermore, because it contains an aryl group having two or more fluorine atoms, it is a highly hydrophobic constituent unit, thereby increasing the hydrophobicity of the resist film. For this reason, it is presumed that by using the resist composition of this embodiment with component (F), the hydrophobicity of the resist film and the hydrophilic effect after development due to base decomposition are synergistically enhanced, thereby improving lithography characteristics.

[0355] The resist film formed using the resist composition of this embodiment, by using component (F) described above, exhibits increased hydrophobicity compared to conventional resist compositions. This results in changes to the contact angle with water, such as the static contact angle (the angle between the water droplet surface on the resist film in a horizontal state and the resist film surface), the dynamic contact angle (the contact angle when a water droplet begins to fall when the resist film is tilted; there is a contact angle at the forward endpoint in the direction of the fall (advancing angle) and a contact angle at the backward endpoint in the direction of the fall (receding angle)), and the fall angle (the tilt angle of the resist film when a water droplet begins to fall when the resist film is tilted). For example, the higher the hydrophobicity of the resist film, the larger the static and dynamic contact angles become, while the fall angle decreases.

[0356] Figure 1 illustrates the forward angle (θ1), backward angle (θ2), and backward angle (θ3). Here, the advance angle is the angle θ1 between the surface of the droplet 1 at its lower end 1a and the plane 2 when the plane 2 on which the droplet 1 is placed is gradually tilted, as shown in Figure 1, and the droplet 1 begins to move (fall) on the plane 2. Furthermore, at this time (when the droplet 1 begins to move (fall) on the plane 2), the angle θ2 between the droplet surface at the upper end 1b of the droplet 1 and the plane 2 is the receding angle, and the inclination angle θ3 of the plane 2 is the falling angle.

[0357] In this specification, the static contact angle, dynamic contact angle, and fall angle can be measured, for example, as follows. First, a resist composition solution is spin-coated onto a silicon substrate, and then heated under predetermined conditions, for example, at a temperature of 80-115°C for 60 seconds to form a resist film. Next, the above-mentioned resist film can be measured using commercially available measuring devices such as DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.), AUTO SLIDING ANGLE:SA-30DM (product name, manufactured by Kyowa Interface Science Co., Ltd.), and AUTO DISPENSER:AD-31 (product name, manufactured by Kyowa Interface Science Co., Ltd.).

[0358] In this embodiment, the resist composition is prepared by coating a 12-inch silicon wafer with the resist composition using a spinner, pre-baking it on a hot plate at 100°C for 60 seconds, and drying it. The measured value of the receding angle (receding angle 1) in the dynamic contact angle of the 80 nm thick resist film is preferably 70° or greater, more preferably 72° or greater, and even more preferably 73° or greater. A measured receding angle of 70° or greater indicates sufficient hydrophobicity of the resist film, resulting in superior lithography characteristics. Furthermore, it allows for faster scanning speeds in immersion exposure.

[0359] Furthermore, for a film developed from the above-mentioned resist film, if the receding angle after development, measured in the same manner as the dynamic contact angle, is defined as receding angle 2, then the Δ contact angle calculated by the following formula 1 is preferably 3° or more, more preferably 5° or more, and even more preferably 7° or more. If the Δ contact angle is 7° or more, the film exhibits high hydrophilicity after development and is superior to Blob defects. Furthermore, the delta-contact angle is preferably 20° or less, more preferably 17° or less, and even more preferably 15° or less. If the delta-contact angle is 20° or less, the stability over time is excellent.

[0360] (Formula 1): Δcontact angle = receding angle 1 - receding angle 2

[0361] The Δ contact angle is the difference between receding angle 1 and receding angle 2, and serves as an indicator of base degradation.

[0362] (Method for forming resist patterns) A resist pattern formation method according to a second embodiment of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition of the above-described embodiment, exposing the resist film, and developing the exposed resist film to form a resist pattern. One embodiment of such a resist pattern formation method is, for example, a resist pattern formation method carried out as follows.

[0363] First, the resist composition of the above embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus, either through exposure via a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without going through a mask pattern. After that, a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, an alkaline developer is used, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used. After the developing process, a rinsing process is preferably performed. In the case of an alkaline developing process, a water rinse using pure water is preferred, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, a process may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After development or rinsing, the film is dried. In some cases, a bake (post-bake) process may be performed after the development process. In this way, a resist pattern can be formed.

[0364] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0365] The wavelength used for exposure is not particularly limited, and can be used with radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for use with KrF excimer lasers, ArF excimer lasers, EB, or EUV.

[0366] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography, but liquid immersion lithography is preferred. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. The refractive index of such a solvent is not particularly limited as long as it is within the aforementioned range. Examples of solvents having a refractive index greater than that of air and less than that of the resist film include water, fluorinated inert liquids, silicone solvents, and hydrocarbon solvents. Water is preferably used as the immersion medium.

[0367] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer solution used in the solvent development process can be any solvent capable of dissolving component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0368] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0369] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0370] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorine-based and / or silicone-based surfactants can be used.

[0371] The development process can be carried out by known development methods, such as immersing the support in developer for a certain period of time (dip method), piling up developer on the surface of the support by surface tension and leaving it still for a certain period of time (paddle method), spraying developer onto the surface of the support (spray method), or continuously dispensing developer while scanning a developer dispensing nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispensing method).

[0372] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously dispensing the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0373] The resist compositions of the embodiments described above, and the various materials used in the pattern forming methods of the embodiments described above (for example, resist solvents, developers, rinse solutions, anti-reflective film forming compositions, topcoat forming compositions, etc.) are preferably free from impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The impurity content in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0374] In the resist pattern formation method of this embodiment described above, since the resist composition according to the embodiment of the present invention described above is used, it is possible to form a resist pattern that reduces environmental impact and has excellent lithography characteristics when forming a resist pattern.

[0375] [Polymer compound] The polymer compound according to the third embodiment of the present invention has a constituent unit (f1) represented by the following general formula (f1-1) and a constituent unit (fa1) represented by the following general formula (fa-1), and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group.

[0376] [ka]

[0377] [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf1 is a divalent linking group. Ar is an aryl group. nf1 is an integer greater than or equal to 1.

[0378] [ka]

[0379] [In general formula (fa-1), R 01 Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. 01 n is a divalent hydrocarbon group which may have an ether bond. f01 Rfa is an integer between 0 and 2. 01 This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

[0380] The polymer compound (F1) according to the third embodiment of the present invention is the same as described above for the polymer compound (F1) in the resist composition according to the embodiments of the present invention, and the preferred polymer compound is also the same.

[0381] Such polymer compound (F1) is useful as a fluorine additive component (F) for resist compositions. By using such polymer compound (F1) in a chemically amplified resist composition, it is possible to form a resist pattern that reduces environmental impact and has excellent lithographic properties during resist pattern formation.

[0382] [Fluorine additive ingredients] The fluorine additive component according to the fourth embodiment of the present invention contains a polymer compound having a constituent unit (f1) represented by the following general formula (f1-1) and a constituent unit (fa1) represented by the following general formula (fa-1), and not containing any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group.

[0383] [ka]

[0384] [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf1 is a divalent linking group. Ar is an aryl group. nf1 is an integer greater than or equal to 1.

[0385] [ka]

[0386] [In general formula (fa-1), R 01 Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. 01 n is a divalent hydrocarbon group which may have an ether bond. f01 Rfa is an integer between 0 and 2. 01 This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

[0387] The polymer compound (F1) in the fluorine additive component (F) according to the fourth embodiment of the present invention is the same as described above for the polymer compound (F1) according to the embodiments of the present invention, and the preferred polymer compound is also the same.

[0388] Such fluorine additive component (F) is the same as described above for the fluorine additive component (F) for the resist composition according to the embodiments of the present invention, and the preferred components are also the same. By using such a fluorine additive component (F) in a chemically amplified resist composition, it is possible to form a resist pattern that reduces environmental impact and simultaneously suppresses WMD (Wet Microwave Deposition) and Blob defects, which are necessary in the TC-Less process. [Examples]

[0389] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0390] <Examples of compound synthesis> [Synthesis Example 1: Synthesis of Compound (f)-1] Compound (f)-1 was synthesized using the following synthesis method.

[0391] [ka]

[0392] Under a nitrogen atmosphere, 4.3 g of compound (X1), 3.0 g of compound (Y1), 0.03 g of dimethylaminopyridine, and 15 g of dichloromethane were added to a three-necked flask and stirred at a temperature below 10°C. 2.9 g of diisopropylcarbodiimide was then added while maintaining the temperature, and the mixture was stirred at a temperature below 10°C for 0.5 hours. The temperature was then raised to 25°C and the mixture was stirred for 12 hours. The reaction mixture was then filtered, and the filtrate was washed three times with 100 g of 1% citric acid aqueous solution, followed by three washes with 100 g of pure water. After washing, the mixture was concentrated to dryness using a rotary pump, yielding 4.4 g of white solid (f)-1 (yield 6%). 5% was obtained.

[0393] The obtained compound (f)-1 was subjected to NMR measurement, and its structure was identified based on the following analytical results.

[0394] 1H NMR: δ 0.89 (3H, t, J = 6.8 Hz), 1.75-1.91 (5H, 1.82 (dq, J = 7.0, 6.8 Hz), 1.86 (s)), 4.80 (2H, s), 5.27 (1H, t, J = 7.0 Hz), 5.56 (1H, d, J = 3.8 Hz), 6.06 (1H, d, J = 3.8 Hz)

[0395] [Synthesis Example 2: Synthesis of Compound (f)-2] Compound (f)-2 was synthesized using the following synthesis method.

[0396] [ka]

[0397] Compound (f)-4 was obtained using the same method as in Synthesis Example 1, except that compound (X1) was changed to compound (X2).

[0398] The obtained compound (f)-2 was subjected to NMR measurement, and its structure was identified based on the following analytical results.

[0399] 1 H NMR: δ 1.26-1.66 (10H, 1.33 (dtt, J = 12.1, 6.5, 2.8 Hz), 1.47 (dtt, J = 12.8, 6.5, 2.8 Hz), 1.58 (dtd, J = 13.4, 6.5, 2.8 Hz)), 1.86 (3H, s), 2.24 (1H, tdt, J = 10.3, 3.0, 2.8 Hz), 4.82 (2H, s), 5.10 (1H, d, J = 3.0 Hz), 5.56 (1H, d, J = 3.8 Hz), 6.06 (1H, d, J = 3.8 Hz).

[0400] [Synthesis Example 3: Synthesis of Compound (f)-3] Compound (f)-3 was synthesized using the following synthesis method.

[0401] [ka]

[0402] Compound (f)-3 was obtained using the same method as in Synthesis Example 1, except that compound (X1) was changed to compound (X3).

[0403] The obtained compound (f)-3 was subjected to NMR measurement, and its structure was identified based on the following analytical results.

[0404] 1 H NMR: δ 1.86 (3H, s), 3.60 (2H, d, J = 5.6 Hz), 4.78 (2H, s), 5.41 (1H, t, J = 5.6 Hz), 5.56 (1H, d, J = 3.8 Hz), 6.06 (1H, d, J = 3.8 Hz).

[0405] [Synthesis of polymer compound (F)-1] The target polymer compound (F)-1 was obtained by polymerization using the corresponding raw material monomers by a conventional method.

[0406] For the obtained polymer compound (F)-1, the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 25,000, and the molecular weight dispersion (PDI) (Mw / Mn) was 1.6. Also, carbon-13 nuclear magnetic resonance spectrum ( 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 75 / 25.

[0407] [Synthesis of polymer compound (F)-2 ~ polymer compound (F)-5, polymer compound (F2)-1 ~ polymer compound (F2)-4] The polymer compounds (F)-2 to (F)-5 and (F2)-1 to (F2)-4 listed below were obtained by polymerization using the corresponding raw material monomers, in the same manner as for [polymer compound (F)-1] above, by conventional methods.

[0408] The structure, weight-average molecular weight (Mw), molecular weight dispersion (PDI), and copolymerization composition ratio (molar ratio) of each obtained polymer compound are shown below.

[0409] [ka]

[0410] [ka]

[0411] [ka]

[0412] <Preparation of the resist composition> (Examples 1-10, Comparative Examples 1-4) Each of the components shown in Table 1 was mixed and dissolved to prepare the resist compositions for each example.

[0413] [Table 1]

[0414] In Table 1, each abbreviation has the following meaning. The unit of composition is parts by mass.

[0415] A-1: A polymer compound represented by the following chemical formula (A)-1. For this polymer compound (A)-1, the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 7100, and the molecular weight dispersion (Mw / Mn) is 1.6. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0416] A-2: A polymer compound represented by the following chemical formula (A)-2. For this polymer compound (A)-2, the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 7000, and the molecular weight dispersion (Mw / Mn) is 1.6. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0417] A-3: A polymer compound represented by the following chemical formula (A)-3. For this polymer compound (A)-3, the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 7000, and the molecular weight dispersion (Mw / Mn) is 1.6. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0418] A-4: A polymer compound represented by the following chemical formula (A)-4. For this polymer compound (A)-4, the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 7000, and the molecular weight dispersion (Mw / Mn) is 1.5. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0419] [ka]

[0420] B-1~B-2: Acid generators consisting of the following compounds (B)-1~(B)-2, respectively.

[0421] [ka]

[0422] D-1 to D-3: Acid diffusion control agents consisting of compounds represented by the following chemical formulas (D)-1 to (D)-3.

[0423] [ka]

[0424] F-1 to F-5, F2-1 to F2-4: Fluorine additive components composed of the compounds represented by the above (F)-1 to (F)-5, (F2)-1 to (F2)-4.

[0425] S-1: A mixed solvent of 2925 parts by mass of propylene glycol monomethyl ether acetate, 450 parts by mass of propylene glycol monomethyl ether, and 1125 parts by mass of cyclohexanone

[0426] <Formation of resist film> On a 12-inch silicon wafer, each resist composition of Examples 1 to 10 and Comparative Examples 1 to 4 was applied using a spinner, and pre-baked (PAB) at 100 °C for 60 seconds on a hot plate and dried to form a resist film with a film thickness of 80 nm.

[0427] <Evaluation of contact angle> (Contact angle) Water was dropped onto the surface of the resist film formed by the above <Formation of resist film>, and the dynamic contact angle (receding angle 1) was measured using DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.) (Measurement of contact angle: 50 μL of water). (Contact angle after development) The resist film formed by the above <Formation of resist film> was subjected to alkali development with a 2.38 mass% aqueous TMAH solution (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 °C for 15 seconds, then rinsed with pure water for 15 seconds, and spin-dried. For the surface of the developed film, the dynamic contact angle (receding angle 2) after development was measured in the same manner as the contact angle after coating.

[0428] The Δ contact angle was calculated by the following formula 1 and described in the table. (Formula 1): Δ contact angle = receding angle 1 - receding angle 2

[0429] <Evaluation of Blob defects> An organic antireflective film composition "ARC-29A" (trade name, manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and baked at 205 °C for 60 seconds on a hot plate to dry, thereby forming an organic antireflective film with a film thickness of 89 nm. Each resist composition of Examples 1 to 10 and Comparative Examples 1 to 4 was respectively applied onto the organic antireflective film, and prebaked (PAB) at 100 °C for 60 seconds on a hot plate and dried, thereby forming a resist film with a film thickness of 80 nm.

[0430] Using an immersion ArF exposure apparatus XT1900Gi [manufactured by ASML; NA (numerical aperture) = 0.95, Dipole (in / out = 0.668 / 0.829), TE-pol, immersion medium: water], an ArF excimer laser (193 nm) was selectively irradiated through a photomask (6% halftone). Thereafter, a PEB treatment was performed at 90 °C for 60 seconds. Subsequently, alkali development was performed with a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 °C for 10 seconds, and then, water rinsing was performed with pure water for 15 seconds, followed by spin drying. As a result, a 1:1 line and space (LS) pattern with a line width of 70 nm and a pitch of 140 nm was formed in each of the examples. The LS pattern obtained above was observed using a surface defect observation apparatus KLA2905 (product name) manufactured by KLA Tencor. The number of Blob defects per silicon wafer was measured and evaluated according to the following evaluation criteria.

[0431] (Evaluation criteria) ◎: The number of Blob defects is 0 to 10. ○: The number of Blob defects is 11 to 30. ×: The number of Blob defects exceeds 30.

[0432] <Evaluation of WMD> For the LS patterns described above, the number of WMDs per silicon wafer was measured using the same KLA2905 and evaluated according to the following evaluation criteria. The WMDs were limited to those with a particle size of 1 μm or larger.

[0433] (Evaluation Criteria) ◎: Number of Blob defects is 0 ○: Number of Blob defects is 1 to 10 ×: Number of Blob defects exceeds 10

[0434] <Environmental regulations> Each example of the resist composition was evaluated according to the following evaluation criteria. OK (Good): The (F) component does not contain any compounds having a perfluoroalkyl skeleton or a difluoromethyl group. NG (Poor): Component (F) contains either a compound having a perfluoroalkyl skeleton or a compound having a difluoromethyl group.

[0435] The results shown in Table 1 confirm that the resist film formed with the resist composition of this embodiment exhibits a larger difference between the contact angle with water on the surface immediately after deposition and the contact angle with water on the surface after development compared to conventional resists, indicating sufficient base degradability. Furthermore, it was confirmed that the resist composition of the embodiment to which the present invention is applied can form a resist pattern that reduces environmental impact and simultaneously suppresses WMDs and Blob defects, which are necessary in the TC-Less process.

Claims

1. A resist composition that generates acid upon exposure, and whose solubility in a developer changes due to the action of the acid, It contains a base component (A) whose solubility in the developer solution changes due to the action of acid, an acid generating agent component (B) that generates acid upon exposure, and a fluorine additive component (F). The aforementioned fluorine additive component (F) comprises a constituent unit (f1) represented by the following general formula (f1-1), It contains a polymer compound (F1) having a constituent unit (fa1) represented by the following general formula (fa-1), and does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. Resist composition. 【Chemistry 1】 [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf is a divalent linking group. Ar is an aryl group. nf １ [ is an integer greater than or equal to 1.] 【Chemistry 2】 [In general formula (fa-1), R ０１ Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. ０１ n is a divalent hydrocarbon group which may have an ether bond. ｆ０１ Rfa is an integer between 0 and 2. ０１ This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

2. The Rfa in the constituent unit (fa1) containing the acid-degradable group ０１ The resist composition according to claim 1, wherein the resist is represented by any of the following general formulas (fa1-r2-1) to (fa1-r2-4). 【Transformation 3】 Formulas (fa1-r2-1) to (fa1-r2-4) are acid-dissociable groups with 8 or more carbon atoms. In formula (fa1-r2-1), Rfa ０３１ represents an alkyl group, and Yfab ０ represents a carbon atom. Xfab ０ represents a group that forms a monocyclic alicyclic hydrocarbon group together with Yfab ０ and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted. In formula (fa1-r2-2), Yfa is a carbon atom. Xfa is a group that, together with Yfa, forms a monocyclic hydrocarbon group. Some or all of the hydrogen atoms in this monocyclic hydrocarbon group may be substituted. Rfa １０１ ~Refa １０３ Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Rfa １０１ ~Refa １０３ Two or more of these may be bonded together to form a ring structure. In formula (fa1-r2-3), Yfaa is a carbon atom. Xfaa is a group that, together with Yfaa, forms a monocyclic aliphatic cyclic group. Rfa １０４ This is an aromatic hydrocarbon group which may have substituents. In the formula (fa1-r2-4), Rfa' １２ and Rfa' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Rfa' １４ This is a monocyclic hydrocarbon group which may have substituents. * indicates a bond.

3. Furthermore, the resist composition according to claim 1 or 2, further comprising an acid diffusion control agent component (D) that controls the diffusion of acid generated from the acid generating agent component (B) by exposure.

4. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition described in claim 1 or 2; exposing the resist film; and developing the resist film to form a resist pattern.

5. The constituent unit (f1) is represented by the following general formula (f1-1), It has a constituent unit (fa1) represented by the following general formula (fa-1), A polymer compound (F1) that does not contain any compounds having a perfluoroalkyl skeleton or any compounds having a difluoromethyl group. 【Chemistry 4】 [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf is a divalent linking group. Ar is an aryl group. nf １ [ is an integer greater than or equal to 1.] 【Transformation 5】 [In general formula (fa-1), R ０１ Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. ０１ n is a divalent hydrocarbon group which may have an ether bond. ｆ０１ Rfa is an integer between 0 and 2. ０１ This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

6. The constituent unit (f1) is represented by the following general formula (f1-1), It contains a polymer compound having a constituent unit (fa1) represented by the following general formula (fa-1), A fluorine additive component that does not contain any compounds having a perfluoroalkyl skeleton or compounds having a difluoromethyl group. 【Transformation 6】 [In the general formula (f1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Lf is a divalent linking group. Ar is an aryl group. nf １ [ is an integer greater than or equal to 1.] 【Transformation 7】 [In general formula (fa-1), R ０１ Vfa is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. ０１ n is a divalent hydrocarbon group which may have an ether bond. ｆ０１ Rfa is an integer between 0 and 2. ０１ This refers to an acid-dissociable group containing a monocyclic hydrocarbon group and having eight or more carbon atoms.

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