Resist composition and method for forming a resist pattern

Abstract

This resist composition contains: a resin component (A1) having a constituent unit (a1) that includes an acid-decomposable group the polarity of which increases under the action of acid, a constituent unit (a10) represented by general formula (a10-1), and a constituent unit (a5) represented by general formula (a5-1); and a resin component (Z) that has a constituent unit (z1) represented by general formula (z1-1) and that does not include an acid-dissociable group (where Wax1 is an aromatic hydrocarbon group, Ra5 is an acid non-dissociable aliphatic cyclic group in which some of the carbon atoms forming the ring skeleton may be substituted with an oxygen atom, and Rz0 is a hydrocarbon group that does not contain an acid-dissociable group or a hydrogen atom).

Description

[Technical Field]

[0001] The present invention relates to a resist composition and a resist pattern forming method. This application claims priority based on Japanese Patent Application No. 2022-008707, filed in Japan on January 24, 2022, and the contents of that application are incorporated herein by reference. [Background technology]

[0002] 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 is achieved by shortening the wavelength (increasing the energy) of the exposure light source.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution that can reproduce patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements. These compositions contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates acid upon exposure.

[0004] In the manufacturing of semiconductor packages, MEMS, etc., there is a process of forming a thick resist film on the surface of the workpiece to create a resist pattern and then performing etching. When a chemically amplified resist composition is used in this process, as the thickness of the resist film increases, it becomes difficult to maintain sensitivity during exposure, the resolution for development decreases, and it becomes difficult to obtain the desired resist pattern shape. In addition, as the thickness of the resist film increases, cracks are more likely to occur in the resist pattern.

[0005] Patent Document 1 proposes a resist composition containing a resin component having constituent units containing acid-degradable groups and constituent units derived from hydroxystyrene, and a plasticizer component having constituent units of a specific structure that do not contain acid-dissociable groups, wherein the content of the plasticizer component is 50 parts by mass or less per 100 parts by mass of the resin component, and the solid content concentration is 25% by mass or more. According to this resist composition, it is possible to form a thick resist film, and to form a resist pattern that is less prone to cracking and less prone to surface roughness during etching. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2021-92659 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, with the increasing integration of LSIs and the advancement of communication speeds, there is a growing demand for increased memory capacity, and further miniaturization of patterns is rapidly progressing. However, while electron beam and EUV lithography aim to form fine patterns of several tens of nanometers, there are still many challenges, such as low productivity, and there are limitations to microfabrication technology. In response to this, in addition to miniaturization, development is underway on 3D structured devices that aim to increase memory capacity by stacking cells.

[0008] In the manufacturing of the aforementioned three-dimensional structure device, a thick resist film, such as one with a thickness of 5 μm or more, is deposited on the surface of the workpiece to form a resist pattern, and etching is performed. When a chemically amplified resist composition is used, increasing the thickness of the resist makes it difficult for the exposure light source to reach the bottom of the resist film, thus requiring a more transparent resist. To improve transparency, the mainstream approach is to reduce the amount of constituent units derived from hydroxystyrene in the substrate components, but this raises concerns that the difference in CD between the top and bottom of the pattern (ΔCD) will widen, resulting in a tapered resist shape after patterning. Furthermore, pattern CD can also be affected by processes such as the setting of the resist film after exposure. Furthermore, increasing the thickness of the resist increases the risk of crack formation due to thermal shrinkage during the process, so there was room for improvement. Furthermore, as the resist becomes thicker, its viscosity increases, raising concerns about poor handling, such as clogging of pipes during resist manufacturing and transportation.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a resist pattern composition that has appropriate viscosity, good handling properties, is less susceptible to process influences during pattern formation, reduces crack occurrence, and can form a thick film resist pattern with good shape, and a method for forming a resist pattern using the resist composition. [Means for solving the problem]

[0010] To solve the above problems, the present invention employs the following configuration. In other words, the first aspect 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, comprising: a constituent unit (a1) containing an acid-degradable group whose polarity increases due to the action of the acid; a constituent unit (a10) represented by the following general formula (a10-1); a resin component (A1) having a constituent unit (a5) represented by the following general formula (a5-1); and a resin component (Z) having a constituent unit (z1) represented by the following general formula (z1-1) and not containing an acid-dissociable group.

[0011] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1 n is an aromatic hydrocarbon group which may have substituents. ax1 [ is an integer greater than or equal to 1.]

[0012] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ra 5 This is an acid-non-dissociable aliphatic cyclic group in which some of the carbon atoms forming the ring skeleton may be substituted with oxygen atoms.

[0013] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. Vz 0 This is a divalent hydrocarbon group which may contain a single bond or a heteroatom. However, Vz 0 If it is a divalent hydrocarbon group which may contain a heteroatom, then Vz 0 It does not contain acid-dissociating groups. Rz 0 [This refers to a hydrogen atom or a group represented by the following general formula (z1-r-1).]

[0014] [Chemical formula] [In the formula, Rz 01 is a hydrocarbon group which may have a substituent. Rz 02 is a hydrogen atom or a hydrocarbon group which may have a substituent. Rz 01 and Rz 02 and Rz 01 and Rz 02 may be bonded to each other to form a ring structure. However, Rz 01 and Rz 02 do not contain an acid dissociable group. * represents a bond.]

[0015]

[0016] According to the present invention, there can be provided a resist pattern composition capable of forming a thick film resist pattern having an appropriate viscosity, good handling properties, being less affected by the process during pattern formation, reducing the occurrence of cracks, and having a good shape, and a resist pattern forming method using the resist composition.

[0017] In the present specification and the claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, a compound, etc. having no aromaticity. "Alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in an alkoxy group. "Alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified. "Halogen atom" includes fluorine atom, chlorine atom, bromine atom and iodine atom. "Constituent unit" refers to the monomer unit (monomer unit) that makes up a polymer compound (resin, polymer, copolymer). When it is stated that a group "may have substituents," this includes both cases where a hydrogen atom (-H) is substituted with a monovalent group and cases where a methylene group (-CH2-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation exposure.

[0018] 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). 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).

[0019] The term "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.

[0020] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, "low molecular weight compound" refers to a nonpolymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, "resin," "high molecular weight compound," or "polymer" refers to a polymer with a molecular weight of 1000 or more. The molecular weight of polymers shall be the weight-average molecular weight on a polystyrene basis calculated by GPC (gel permeation chromatography).

[0021] "Induced structural units" refer to structural units formed by the cleavage of multiple bonds between carbon atoms, such as ethylenic double bonds. "Acrylic acid ester" may have a substituent that replaces the hydrogen atom bonded to the α-carbon atom. αx ) is an atom or group other than a hydrogen atom. Also, substituents (R αx Itaconic acid diesters in which ) are substituted with substituents containing an ester bond, or substituents (R αx This 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 acrylic acid is bonded. Hereafter, 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.

[0022] The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound (which may have the α-position 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 target compound (which may have the α-position hydrogen atom substituted with a substituent). Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. As substituents that substitute the hydrogen atom at the α-position of hydroxystyrene, R αx Similar examples include the above.

[0023] In this specification and in the claims, 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.

[0024] (Resist composition) A resist composition according to a first aspect of the present invention generates acid upon exposure and its solubility in a developer solution changes due to the action of the acid, and contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer solution changes due to the action of the acid, and a resin component (Z) (hereinafter also referred to as "component (Z)") that does not contain acid-dissociable groups. When a resist film is formed using such a resist composition, a thick resist film (for example, with a film thickness of 5 to 20 μm) can be formed.

[0025] When a resist film is formed using such a resist composition and selective exposure is performed on the resist film, acid is generated in the exposed 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.

[0026] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive-type resist pattern is referred to as a positive-type resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative-type resist pattern is referred to as a negative-type 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 used for an alkaline development process in which an alkaline developer is used for the development process during resist pattern formation, or for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development process.

[0027] The resist composition of this embodiment has an acid-generating ability that generates acid upon exposure, and component (A) may generate acid upon exposure, or an additive component formulated separately from component (A) may generate acid upon exposure. The resist composition of this embodiment may specifically (1) further contain an acid generating agent component (B) (hereinafter referred to as "component (B)") that generates acid upon exposure; (2) component (A) may be a component that generates acid upon exposure; or (3) component (A) may be a component that generates acid upon exposure and also contains component (B). In other words, in the cases of (2) and (3) above, 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." 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 resin having a constituent unit that generates acid upon exposure can be used. Known constituent units that generate acid upon exposure can be used. Among these, the resist composition of this embodiment is preferably the case of (1) above.

[0028] <(A) component> In the resist composition of this embodiment, 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. By using component (A1), the polarity of the substrate component 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).

[0029] When an alkaline development process is applied, the substrate component containing component (A1) is poorly soluble in the alkaline developer before exposure. For example, when acid is generated from component (B) upon exposure, the polarity increases due to the action of the acid, and the 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.

[0030] On the other hand, when a solvent development process is applied, the substrate component containing component (A1) is highly soluble in organic developer before exposure. For example, when acid is generated from component (B) due to exposure, the polarity increases due to the action of the acid, and the solubility in organic developer decreases. 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 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.

[0031] In the resist composition of this embodiment, component (A) may be used alone or in combination of two or more types.

[0032] (A1) About the ingredients Component (A1) is a polymer compound having a constituent unit (a1) containing an acid-degradable group whose polarity increases with the action of an acid, a constituent unit (a10) represented by general formula (a10-1), and a constituent unit (a5) represented by general formula (a5-1). (A1) Component may have other constituent units other than constituent unit (a1), constituent unit (a10), and constituent unit (a5).

[0033] ≪Component 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.

[0034] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, proposed acid-dissociable groups for base resins used in chemically amplified resist compositions include the following: "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0035] 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 general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0036] [ka] [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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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) x5 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 refers to 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. However, R P1 and R P2 Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the 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.

[0043] 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.

[0044] 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."

[0045] [ka] [In the formula, Ra' 4 ~Ra' 6 Each of these is a hydrocarbon group, Ra' 5 , Ra' 6 They may be joined to each other to form a ring.

[0046] Ra' 4 Examples of hydrocarbon groups 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 Similar examples include the above. 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 Similar examples include the above.

[0047] Ra' 5 and Ra' 6When these groups bond to each other to form a ring, the following groups are preferred: the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), and the group represented by the general formula (a1-r2-3). Meanwhile, Ra' 4 ~Ra' 6 When these are independent hydrocarbon groups that are not bonded to each other, the groups represented by the following general formula (a1-r2-4) are preferred.

[0048] [ka] [In formula (a1-r2-1), Ra' 10 This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. 11 Ra' 10 This indicates a group that forms an aliphatic cyclic group with a bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group 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' 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. 14 This is a hydrocarbon group that may have substituents. * represents a bond.

[0049] In the above equation (a1-r2-1), Ra' 10 This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0050] Ra' 10 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' 10 In this, the branched alkyl group is the Ra' 3 Similar examples include the above.

[0051] Ra' 10 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.

[0052] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred, with cyclopentyl groups being even more preferred.

[0053] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa and Ya is the Ra' in the above formula (a1-r-1). 3 Examples thereof include a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in 3 . The cyclic hydrocarbon group formed by Xa and Ya may have a substituent. Examples of this substituent include the same substituents that the cyclic hydrocarbon group in the above Ra' 3 may have. In formula (a1-r2-2), Ra 101 ~Ra 103 Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and the like. Ra 101 ~Ra 103 Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, an adamantyl group, and the like. Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis, a hydrogen atom and a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms are preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0054] Examples of the substituent of the linear saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the above Ra[[ID=D29]] 101 ~Ra 103 include, for example, the same groups as the above Ra[[ID=3D]]<D= x5 and the like.

[0055] Ra 101~Ra 103 Groups containing a carbon-carbon double bond formed by two or more of these groups bonding to each other to form a cyclic structure include, for example, cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, and cyclohexyllideneethenyl group. Among these, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis.

[0056] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups listed above, which are monocyclic or polycyclic groups, are preferred. In formula (a1-r2-3), Ra 104 Aromatic hydrocarbon groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring with 5 to 30 carbon atoms. Among them, Ra 104 The 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 benzene or naphthalene with one or more hydrogen atoms removed; and most preferably a group from benzene with one or more hydrogen atoms removed.

[0057] Ra in equation (a1-r2-3) 104 Examples of substituents that may be present include methyl groups, ethyl groups, propyl groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), and alkyloxycarbonyl groups.

[0058] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13In this context, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above-mentioned Ra 101 ~Ra 103 Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, hydrogen atoms and alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. The above Ra' 12 and Ra' 13 When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra x5 Similar bases can be cited.

[0059] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group that may have substituents. 14 Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0060] 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.

[0061] Ra' 14 The branched alkyl group in this 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, etc., with isopropyl group being preferred.

[0062] 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, tricyclodecane, tetracyclododecane, and the like.

[0063] 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' 14 The 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.

[0064] 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) 14When it is an anthryl group, the position bonding to the tertiary carbon atom in the formula (a1-r2-4) may be any of the 1-position, 2-position or 9-position of the anthryl group.

[0065] Specific examples of the group represented by the formula (a1-r2-1) are given below.

[0066] [Chemical formula]

[0067] [Chemical formula]

[0068] [Chemical formula]

[0069] Specific examples of the group represented by the formula (a1-r2-2) are given below.

[0070] [Chemical formula]

[0071] [Chemical formula]

[0072] [Chemical formula]

[0073] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0074] [Chemical formula]

[0075] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0076] [ka]

[0077] Tertiary alkyloxycarbonyl acid dissociable group: Among the aforementioned polar groups, an example of an acid-dissociating group that protects a hydroxyl group is the acid-dissociating group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as a "tertiary alkyloxycarbonyl acid dissociating group" for convenience).

[0078] [ka] [In the formula, Ra' 7 ~Ra' 9 These are each alkyl groups.

[0079] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of these is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 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.

[0080] Examples of constituent units (a1) include constituent units derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, constituent units derived from acrylamide, constituent units derived from hydroxystyrene or hydroxystyrene derivatives in which at least a portion of the hydrogen atoms in the hydroxyl group of a constituent unit are protected by a substituent containing the acid-degradable group, and constituent units derived from vinyl benzoic acid or vinyl benzoic acid derivatives in which at least a portion of the hydrogen atoms in the -C(=O)-OH group are protected by a substituent containing the acid-degradable group.

[0081] As for the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent is preferred. A preferred specific example of such a constituent unit (a1) is a constituent unit represented by the following general formula (a1-1) or (a1-2).

[0082] [ka] [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 is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-2) above. 1 is n a2 It is a +1 valent hydrocarbon group, n a2 is an integer between 1 and 3, and Ra 2 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0083] In formula (a1-1), the C1-C5 alkyl group of 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 C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. 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.

[0084] In the above formula (a1-1), Va 1The divalent hydrocarbon group in [description] may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0085] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in [description] may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0086] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. 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.

[0087] 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 with two hydrogen atoms 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 with two hydrogen atoms removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0088] 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.

[0089] In the above formula (a1-1), Ra 1 This is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0090] In the above formula (a1-2), Wa 1 n in a2The +1 valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that is a combination of a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. The aforementioned n a2 The +1 valent is preferably 2 to 4 valent, and more preferably 2 or 3 valent.

[0091] In the above formula (a1-2), Ra 2 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0092] The following are specific examples of the constituent units represented by the above formula (a1-1). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] The constituent units (a1) of component (A1) may be one type or two or more types. As the constituent unit (a1), the constituent unit represented by formula (a1-1) is more preferable. Among these, the constituent unit (a1) is particularly preferred if it includes a constituent unit represented by the following general formula (a1-1-1).

[0102] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4).

[0103] In the above formula (a1-1-1), R, Va 1 and n a1 R, Va in the above formula (a1-1) 1 and n a1 It is similar to that. The explanation of the acid-dissociable groups represented by the general formulas (a1-r2-1), (a1-r2-3), or (a1-r2-4) is as described above.

[0104] In the above formula (a1-1-1), Ra 1 " is preferably an acid-dissociable group represented by the general formula (a1-r2-1) or (a1-r2-4) among the above.

[0105] The proportion of constituent units (a1) in component (A1) is preferably 5 to 60 mol%, more preferably 10 to 55 mol%, even more preferably 15 to 50 mol%, and particularly preferably 20 to 45 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 be above the lower limit of the preferred range described above, lithography characteristics such as sensitivity, resolution, and roughness improvement are enhanced. On the other hand, if it is below the upper limit of the preferred range described above, a balance can be achieved with other constituent units, resulting in good lithography characteristics in various aspects.

[0106] Regarding the constituent unit (a10): The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0107] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1 n is an aromatic hydrocarbon group which may have substituents. ax1 [ is an integer greater than or equal to 1.]

[0108] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. For R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a hydrogen atom is particularly preferred.

[0109] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group. In the above chemical formula, Ya x1The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0110] Ya x1 Preferably, the group is a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, with single bonds and ester bonds [-C(=O)-O-, -OC(=O)-] being more preferred.

[0111] In the above formula (a10-1), Wa x1 This is an aromatic hydrocarbon group which may have substituents. Wa x1 The aromatic hydrocarbon group in this context may be an aromatic ring that may have substituents (n ax1 A group with 1+1 hydrogen atoms removed is an example. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons. 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. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by 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. Also, Wa x1 The aromatic hydrocarbon group in this context is an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ax1 Another example is a group with (+1) hydrogen atoms removed. Among the above, Wa x1 Examples include benzene, naphthalene, anthracene, or biphenyl (n ax1 A group with (+1) hydrogen atoms removed is preferred, and (n ax1A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ax1 A group with (+1) hydrogen atoms removed is even more preferable.

[0112] Wa x1 The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya x1 Examples of substituents for cyclic aliphatic hydrocarbon groups in are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0113] In the above formula (a10-1), n ax1 is an integer greater than or equal to 1, preferably an integer between 1 and 10, more preferably an integer between 1 and 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0114] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] The constituent units (a10) of component (A1) may be one type or two or more types. The proportion of constituent units (a10) in component (A1) is preferably 15 to 60 mol%, more preferably 20 to 55 mol%, even more preferably 25 to 50 mol%, and particularly preferably 30 to 45 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent units (a10) above the lower limit, the shape of the resist pattern tends to be better. On the other hand, by setting it below the upper limit, the transmittance of the resist film improves, making it easier to achieve good sensitivity even in thick resist patterns and to form resist patterns with good shape.

[0119] Regarding the constituent unit (a5): The constituent unit (a5) is a constituent unit represented by the following general formula (a5-1). The presence of the constituent unit (a5) in component (A1) enhances the light transmittance of the resist film compared to the case where the constituent unit contains an aromatic cyclic group. Furthermore, the dry etching resistance of the formed resist pattern is improved, and the hydrophobicity of component (A) is increased. This improved hydrophobicity contributes to improvements in resolution, resist pattern shape, and other properties, particularly when forming resist patterns using solvent development processes. In the constituent unit (a5), the "acid-non-dissociating cyclic group" is a cyclic group that remains in the constituent unit without dissociating even when acid is generated in the resist composition due to exposure (for example, when acid is generated from component (B) described later).

[0120] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ra 5 This is an acid-non-dissociable aliphatic cyclic group in which some of the carbon atoms forming the ring skeleton may be substituted with oxygen atoms.

[0121] In formula (a5-1), the C1-C5 alkyl group of 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 C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. 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, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0122] In the above formula (a5-1), Ra 5 The acid-nondissociable aliphatic cyclic group in this compound may be a monocyclic group or a polycyclic group, and is preferably a monocyclic group. The monocyclic group here is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is more preferably one having 3 to 8 carbon atoms, and even more preferably one having 5 to 8 carbon atoms, specifically including cyclopentane, cyclohexane, and cyclooctane. The polycyclic group here is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. The monocyclic and polycyclic groups may each have, for example, linear or branched alkyl groups having 1 to 5 carbon atoms as substituents.

[0123] In the above formula (a5-1), Ra 5In the acid-nondissociable aliphatic cyclic group, some of the carbon atoms forming the ring skeleton may be substituted with oxygen atoms. Examples of acid-nondissociable aliphatic cyclic groups in which some of the carbon atoms forming the ring skeleton are substituted with oxygen atoms include lactone-containing cyclic groups represented by the general formulas (b2-r-1) to (b2-r-7) described later, with the lactone-containing cyclic group represented by the general formula (b2-r-1) described later being preferred.

[0124] Specifically, examples of constituent units (a5) can be given by the constituent units represented by the following general formulas (a5-1) to (a5-11).

[0125] [ka] [In the formula, R α This is the same as above.

[0126] The constituent units (a5) of component (A1) may be one type or two or more types. Among the above, the constituent unit (a5) is preferably an acid-nondissociable constituent unit containing a monocyclic aliphatic cyclic group, and more preferably at least one selected from the group consisting of constituent units represented by any of the above chemical formulas (a5-7) to (a5-11).

[0127] In component (A1), the proportion of constituent unit (a5) is preferably 5 to 70 mol%, more preferably 10 to 65 mol%, and even more preferably 15 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a5) to above the lower limit of the preferred range mentioned above, the light transmittance of the resist film is further enhanced, resulting in higher sensitivity and improved resolution. On the other hand, by setting it below the upper limit of the preferred range mentioned above, it becomes easier to balance it with other constituent units.

[0128] <<Other constituent units>> Component (A1) may have other constituent units other than constituent unit (a1), constituent unit (a10), and constituent unit (a5) (hereinafter also referred to as "constituent unit (a12)"). Compounds that derive the constituent unit (a12) include, for example, styrene and its derivatives (excluding compounds that derive the constituent unit (a10)); monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having carboxyl groups and ester bonds, such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; and 2-hydroxyethyl Examples include hydroxyalkyl esters of (meth)acrylates such as tyl(meth)acrylate and 2-hydroxypropyl(meth)acrylate; aryl esters of (meth)acrylates such as phenyl(meth)acrylate and benzyl(meth)acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; aliphatic compounds containing vinyl groups such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; polymerizable compounds containing nitrile groups such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; polymerizable compounds containing amide bonds such as acrylamide and methacrylamide; and polymerizable compounds containing epoxy groups.

[0129] The constituent units (a12) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a12), the proportion of constituent units (a12) in component (A1) is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, even more preferably 1 to 35 mol%, and particularly preferably 1 to 30 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 (a12) above the lower limit, etching resistance and lithography characteristics are further improved. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other constituent units.

[0130] In the resist composition of this embodiment, component (A) includes a polymer compound (A1) (component (A1)) having constituent units (a1), (a10), and (a5). Preferred components (A1) include polymer compounds having at least structural units (a1), (a10), and (a5). Specifically, polymer compounds having a repeating structure of structural units (a1), (a10), and (a5), and polymer compounds having a repeating structure of structural units (a1), (a10), (a5), and (a12) are preferred.

[0131] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 500 to 50000, more preferably 1000 to 30000, and even more preferably 1000 to 20000. If the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the preferred lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern will be better.

[0132] (A1) The degree of dispersion of component (Mw / Mn) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.5. Mn represents the number-average molecular weight.

[0133] 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 the constituent unit (a10) and, if necessary, a monomer that induces a constituent unit other than the constituent unit (a10) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to this solution, polymerizing it, and then carrying out a deprotection reaction. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group at the terminal. Copolymers in which a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, are introduced are effective in reducing development defects and LER (line edge roughness: uneven unevenness of the line sidewall). Furthermore, component (A1) can also be produced by anionic polymerization using organoalkali metals such as n-butyllithium, s-butyllithium, t-butyllithium, ethyllithium, ethylsodium, 1,1-diphenylhexyllithium, and 1,1-diphenyl-3-methylpentyllithium as polymerization initiators.

[0134] (A2) About the ingredients The resist composition of this embodiment may also include, as component (A), a base component (hereinafter referred to as "component (A2)") that does not correspond to component (A1) and whose solubility in the developer changes due to the action of an acid. (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.

[0135] 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 also be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, it becomes easier to form a resist pattern that is excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement.

[0136] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0137] <(Z) component> Component (Z) is a resin component having a constituent unit (z1) represented by the following general formula (z1-1) and not containing an acid-dissociable group. Here, "acid-dissociable group" refers to both (i) a group having acid-dissociability in which the bond between the acid-dissociable group and an atom adjacent to it can be cleaved by the action of an acid, or (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, which can further cleave the bond between the acid-dissociable group and an atom adjacent to it. In other words, none of the constituent units of component (Z) contain acid-dissociable groups. Therefore, component (Z) does not undergo a deprotection reaction under the action of an acid.

[0138] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. Vz 0 This is a divalent hydrocarbon group which may contain a single bond or a heteroatom. However, Vz 0 If it is a divalent hydrocarbon group which may contain a heteroatom, then Vz 0 It does not contain acid-dissociating groups. Rz 0 [This refers to a hydrogen atom or a group represented by the following general formula (z1-r-1).]

[0139] [ka] [In the formula, Rz 01 Rz is a hydrocarbon group which may have substituents. 02 Rz is a hydrocarbon group which may have a hydrogen atom or a substituent. 01 and Rz 02 These may be bonded to each other to form a ring structure. However, Rz 01 and Rz 02It does not contain acid-dissociating groups. * indicates a bond.

[0140] ≪Constituent Unit (z1)≫ In the above formula (z1-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. The C1-C5 alkyl group in R is preferably a linear or branched alkyl group having C1-C5, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The C1-C5 alkyl halide in R is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine atoms being particularly preferred. R is preferably a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group, and more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group due to their industrial availability, with a hydrogen atom or a methyl group being even more preferred.

[0141] In the above equation (z1-1), Vz 0 The divalent hydrocarbon group in formula (a10-1) which may contain a heteroatom is Ya x1 Examples include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms. However, Vz 0 If it is a divalent hydrocarbon group which may contain a heteroatom, then Vz 0 It does not contain acid-dissociating groups. Among them, Vz 0 For example, a single bond, -C(=O)-OY 21 -or -C(=O)-OY 21 -OC(=O)-Y 22 - is preferred, and a single bond is more preferred. 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].

[0142] In the above equation (z1-1), Rz 0 is a hydrogen atom or a group represented by the general formula (z1-r-1). In the above equation (z1-r-1), Rz 01 Examples of hydrocarbon groups that may have substituents include linear or branched alkyl groups, or cyclic hydrocarbon groups. Rz 01 The linear alkyl group in is preferably having 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. Rz 01 The branched alkyl group in this compound 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, and 2,2-dimethylbutyl group. Rz 01 Some of the carbon atoms constituting the linear or branched alkyl group in the above formula may be substituted with oxygen atoms (-O-). However, in the above formula (z1-r-1), Rz 01 It does not contain an acid-dissociating group. Therefore, in the above formula (z1-r-1), Rz 01 Even if some of the carbon atoms constituting the linear or branched alkyl group in the above formula are substituted with oxygen atoms (-O-), the acetal-type acid-dissociable group represented by formula (a1-r-1) is not included.

[0143] Rz 01The cyclic hydrocarbon group in this can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and it can 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.

[0144] Rz 01 When a cyclic hydrocarbon group in becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The 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. Rz 01Specific 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.

[0145] Rz 01 The cyclic hydrocarbon group in (a1-r-1) may have substituents. The substituent may be Ra' in formula (a1-r-1). 3 The hydrocarbon group in the region may have substituents "Ra x5 Examples include the following.

[0146] In the above equation (z1-r-1), Rz 02 The hydrocarbon group in which substituents may be present is Rz 01 This is similar to a hydrocarbon group which may have substituents.

[0147] In the above equation (z1-r-1), Rz 01 and Rz 02 When these atoms bond to each other to form a ring structure, the ring structure may be a group obtained by removing two hydrogen atoms from a monocycloalkane or polycycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, and the like. 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.

[0148] In the above equation (z1-r-1), Rz 01 is a linear alkyl group or a linear alkoxy group, and Rz 02 Is it a hydrogen atom, or Rz 01 and Rz 02 It is preferable that these elements bond to each other to form a ring structure.

[0149] The constituent units (z1) of component (Z) may be one type or two or more types. In particular, it is preferable that the (Z) component has a constituent unit (z1) represented by the following general formula (z1-1-1) (hereinafter sometimes referred to as "constituent unit (z1-1-1)") and a constituent unit represented by the following general formula (z1-1-2) (hereinafter sometimes referred to as "constituent unit (z1-1-2)").

[0150] [ka] [In the formula, R 01 and R 02 Each of these is independently a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. 01 This is a single bond, -C(=O)-OY 21 -or -C(=O)-OY 21 -OC(=O)-Y 22 - is Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents, and O is an oxygen atom. However, Vz 01 -C(=O)-OY 21 -or -C(=O)-OY 21 -OC(=O)-Y 22 -If Vz 01 It does not contain acid-dissociating groups. Rz 10 -Rz is a linear alkyl group. 11 -O-Rz 12 Alternatively, it is a monovalent alicyclic hydrocarbon group. Rz 11 Rz is a linear alkylene group. 12 It is a linear alkyl group.

[0151] In the above equations (z1-1-1) and (z1-1-2), R 01 and R 02 This is the same as R in the above equation (z1-1). In particular, R 01 The hydrogen atom, methyl group, or trifluoromethyl group is preferred, the hydrogen atom or methyl group is more preferred, and the methyl group is even more preferred. 02 The component is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0152] In the above equation (z1-1-1), Vz 01 -C(=O)-OY 21 -or -C(=O)-OY 21 -OC(=O)-Y 22 -If Y 21 As such, linear aliphatic hydrocarbon groups are preferred, linear alkylene groups are more preferred, linear alkylene groups having 1 to 5 carbon atoms are even more preferred, and methylene groups or ethylene groups are particularly preferred. 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. Among them, Vz 01 A single bond is preferred.

[0153] In the above equation (z1-1-1), Rz 10 The linear alkyl group in this compound preferably has 1 to 10 carbon atoms, and more preferably has 1 to 5 carbon atoms. In the above equation (z1-1-1), Rz 10 ga-Rz 11 -O-Rz 12 If Rz 10 The group is preferably a linear alkylene group having 1 to 5 carbon atoms, and more preferably a methylene group or an ethylene group. 11The group is preferably a linear alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. In the above equation (z1-1-1), Rz 10 The monovalent alicyclic hydrocarbon group in this expression may be either a polycyclic or 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.

[0154] In particular, it is preferable that the (Z) component includes, as a constituent unit (z1-1-2), a constituent unit represented by the following general formula (z1-1-21) (hereinafter sometimes referred to as "constituent unit (z1-1-21)") and a constituent unit represented by the following general formula (z1-1-22) (hereinafter sometimes referred to as "constituent unit (z1-1-22)").

[0155] [ka] [In the formula, R 21 and R 22 Each of these is independently a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. 11 This is a linear alkylene group. Rz 12 Rz is a linear alkyl group. 13 This is a linear alkyl group or a monovalent alicyclic hydrocarbon group.

[0156] In the above formulas (z1-1-21) and (z1-1-22), R 21 and R 22 This is R in the above equation (z1-1-2). 02 It is similar to that. In the above equation (z1-1-21), Rz 11 and Rz 12 This is Rz in the above equation (z1-1-2) 11 and Rz 12 It is similar to that. In the above equation (z1-1-21), Rz 13 In the above formula (z1-1-2), the linear alkyl group or monovalent alicyclic hydrocarbon group is Rz 10 This is similar to a linear alkyl group or a monovalent alicyclic hydrocarbon group in [the relevant context].

[0157] The following are specific examples of the constituent unit (z1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0158] [ka]

[0159] The proportion of constituent units (z1) in component (Z) is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, even more preferably 70 to 100 mol%, and may be 100 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z). By setting the proportion of the constituent units (z1) within the aforementioned preferred range, it becomes easier to suppress the occurrence of cracks and also easier to suppress the occurrence of surface roughness during etching.

[0160] When component (Z) contains the constituent units (z1-1-1) and (z1-1-2) as constituent units (z1), the proportion of constituent unit (z1-1-1) in component (Z) is preferably 1 to 30 mol%, more preferably 3 to 25 mol%, and even more preferably 5 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z). Furthermore, the proportion of constituent unit (z1-1-2) in component (Z) is preferably 70 to 99 mol%, more preferably 75 to 97 mol%, and even more preferably 80 to 95 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z). By setting the proportions of constituent units (z1-1-1) and (z1-1-2) within the aforementioned preferred range, it becomes easier to suppress the occurrence of cracks and to control the viscosity of the resist composition within a range that provides good handling properties.

[0161] When component (Z) contains the constituent units (z1-1-1), (z1-1-21), and (z1-1-22) as constituent units (z1), the proportion of constituent unit (z1-1-1) in component (Z) is preferably 1 to 30 mol%, more preferably 3 to 25 mol%, and even more preferably 5 to 20 mol%, relative to the total amount (100 mol%) of all constituent units constituting component (Z). Furthermore, the proportion of constituent unit (z1-1-21) in component (Z) is preferably 10 to 99 mol%, more preferably 15 to 97 mol%, even more preferably 20 to 95 mol%, and even more preferably 20 to 70 mol%, relative to the total amount (100 mol%) of all constituent units constituting component (Z). Furthermore, the proportion of constituent units (z1-1-22) in component (Z) is preferably 0 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 15 to 70 mol%, and still more preferably 20 to 65 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z). By setting the proportions of constituent units (z1-1-1), (z1-1-21), and (z1-1-22) within the aforementioned preferred range, the viscosity of the resist composition can be easily controlled to a range that provides good handling properties.

[0162] <<Other constituent units>> The (Z) component may have other constituent units in addition to the constituent unit (z1) described above, as needed. Other constituent units include the aforementioned constituent unit (a10), a constituent unit (st) derived from styrene or a styrene derivative, and the aforementioned constituent unit (a1).

[0163] If component (Z) has constituent units (a10), the proportion of constituent units (a10) in component (Z) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and even more preferably 10 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z). By setting the proportion of constituent unit (a10) above the lower limit, sensitivity can be more easily increased. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other constituent units.

[0164] If component (Z) has constituent units (st), the proportion of constituent units (st) in component (Z) is preferably 1 to 30 mol%, and more preferably 3 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (Z).

[0165] The (Z) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, component (Z) is a polymer compound having a repeating structure of the constituent unit (z1). Preferred (Z) components include polymer compounds having a repeating structure of constituent units (z1-1-1) and (z1-1-21); and polymer compounds having a repeating structure of constituent units (z1-1-1), (z1-1-21), and (z1-1-22).

[0166] Such (Z) components 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 (Z) component can be produced by dissolving a monomer that induces the constituent unit (z1) and, if necessary, a monomer that induces a constituent unit other than the constituent unit (z1) in a polymerization solvent, and then adding a radical polymerization initiator as described above to this solution and polymerizing it. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group at the terminal. Copolymers in which a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, are introduced are effective in reducing development defects and LER (line edge roughness: uneven unevenness of the line sidewall).

[0167] The weight-average molecular weight (Mw) of component (Z) (based on polystyrene equivalent by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 5,000 to 200,000, more preferably 10,000 to 150,000, even more preferably 20,000 to 100,000, even more preferably 30,000 to 90,000, and particularly preferably 35,000 to 85,000. When the Mw of component (Z) is within the above preferred range, it becomes easier to suppress the occurrence of cracks and to control the viscosity of the resist composition to a range that provides good handling properties. The dispersion of component (Z) (Mw / Mn) is not particularly limited, but is preferably 1.0 to 9.0, more preferably 1.5 to 7.0, and particularly preferably 3.0 to 6.0. Mn represents the number-average molecular weight.

[0168] In the resist composition of this embodiment, component (Z) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (Z) is preferably 1 to 50 parts by mass, more preferably 5 to 45 parts by mass, even more preferably 10 to 40 parts by mass, and still more preferably 15 to 40 parts by mass, per 100 parts by mass of component (A1). By keeping the content of component (Z) within the preferred range described above, it becomes easier to suppress the occurrence of cracks and to control the viscosity of the resist composition within a range that provides good handling properties.

[0169] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (Z). Examples of other components include components (B), (D), (E), (F), and (S) shown below.

[0170] ≪Acid Generating Agent Component (B)≫ The resist composition of this embodiment may further contain, in addition to components (A) and (Z), 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 includes a compound (B1) consisting of an onium salt (hereinafter referred to as "component (B1)").

[0171] • About ingredient (B1) Examples of component (B1) include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), compounds represented by the general formula (b-2) (hereinafter also referred to as "component (b-2)"), or compounds represented by the general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0172] [ka] [In the formula, R 101 and R 104 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 104 and R105 These may be bonded to each other to form a ring structure. 102 This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 This is a divalent linking group or single bond containing an oxygen atom. 101 ~V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of these is independently either a single bond or an oxygen atom. 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-. m is an integer greater than or equal to 1, and M m+ This is an onium cation with a valence of m.

[0173] {Anion Division} • Anion in component (b-1) In formula (b-1), R 101 This 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.

[0174] Cyclic groups that may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group 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.

[0175] R 101 The aromatic hydrocarbon group in this formula 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. R 101Specific examples of aromatic rings in aromatic hydrocarbon groups 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. R 101 Specific examples of aromatic hydrocarbon groups in this context 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.

[0176] R 101 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. 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, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0177] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, even more preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0178] 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.

[0179] Also, R 101 The cyclic hydrocarbon group in this formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the following general formulas (b2-r-1) to (b2-r-7), -SO2--containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In this case, in the chemical formulas (r-hr-1) to (r-hr-16), * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0180] [ka] [In the formula, Rb' 21Each of these 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, or a lactone-containing cyclic group; B'' 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.

[0181] In the general formulas (b2-r-1) to (b2-r-7), Rb' 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, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Rb' 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Rb' 21 Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Rb' 21 In this mixture, a fluorine atom is preferred as the halogen atom. Rb' 21 The halogenated alkyl group in is the aforementioned Rb' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0182] Rb' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. 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 which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; 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, tricyclodecane, and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (b2-r-1) to (b2-r-7) mentioned above. Rb' 21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Rb' 21 Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0183] Rb' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0184] In the general formulas (b2-r-2), (b2-r-3), and (b2-r-5) above, the alkylene group having 1 to 5 carbon atoms in B'' 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-. B'' 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.

[0185] [ka] [In the formula, Rb' 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, or a -SO2--containing cyclic group; B'' 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. * indicates a bond.

[0186] In the above general formulas (b5-r-1) to (b5-r-2), B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, or an oxygen atom or a sulfur atom. For B'', an alkylene group or -O- having 1 to 5 carbon atoms is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is even more preferred.

[0187] In the above general formulas (b5-r-1) to (b5-r-4), Rb' 51Each of these 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, and among these, each is preferably independently a hydrogen atom or a cyano group.

[0188] [ka]

[0189] R 101 Examples of substituents on the cyclic group 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.

[0190] R 101The cyclic hydrocarbon group in 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. 101 Specific examples of fused ring groups in this context include those represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0191] [ka]

[0192] R 101 Examples of substituents that the fused ring group in the compound may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as substituents of the fused cyclic group are as described above in R 101 Examples of substituents on cyclic groups include those similar to those listed in [reference]. 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, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (b2-r-1) to (b2-r-7); -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4); and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16).

[0193] Chain-like alkyl groups that may have substituents: R 101 The chain-like alkyl group 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. 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.

[0194] A chain-like alkenyl group which may have substituents: R 101 The linear alkenyl group 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 butynyl 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.

[0195] R 101 Examples of substituents in the chain-like alkyl or alkenyl group 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.

[0196] Among the above, R 101 The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically as a cyclic hydrocarbon group, preferred are a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (b2-r-1) to (b2-r-7), respectively; a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively; a group obtained by removing one or more hydrogen atoms from a polycycloalkane or a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively; and an adamantyl group or a -SO2-containing cyclic group represented by the general formula (b5-r-1), respectively.

[0197] If the cyclic hydrocarbon group has substituents, the substituents are preferably hydroxyl groups.

[0198] In formula (b-1), Y 101 It is a single bond or a divalent linking group containing an oxygen atom. Y 101 If Y is a divalent linking group containing an oxygen atom, 101 It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. 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). Note that in the following general formulas (y-al-1) to (y-al-7), R in formula (b-1) above 101 The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0199] [ka] [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.

[0200] 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.

[0201] 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, oshiV' 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.

[0202] Y 101 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5).

[0203] In formula (b-1), V 101 This is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in this product preferably have 1 to 4 carbon atoms. 101 As for the fluorinated alkylene group in V 101Examples include groups in which some or all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms. Among these, V 101 It is preferable that it is a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0204] In formula (b-1), R 102 R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0205] A specific example of the anion part represented by the above formula (b-1) is, for example, Y 101 When it is a single bond, examples include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anions and perfluorobutanesulfonate anions; Y 101 If it is a divalent linking group containing an oxygen atom, the anions can be represented by any of the following formulas (an-1) to (an-4).

[0206] [ka] [In the formula, R” 101 R” is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), or an optionally substituted linear alkyl group. 102 R” 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 the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), respectively, or a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively. 103 V” is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. 101This 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 R'' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each of v'' is an independent integer from 0 to 3, each of q'' is an independent integer from 0 to 20, and n'' is 0 or 1. 104 It is a fluorinated alkyl group.

[0207] R" 101 , R” 102 and R” 103 The aliphatic cyclic group which may have substituents is R in formula (b-1) above. 101 It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0208] R" 103 The aromatic cyclic group which may have substituents in formula (b-1) is R 101 It is preferable that the substituent is the aromatic hydrocarbon group exemplified in the cyclic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0209] R" 101 The chain-like alkyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkyl group in the compound. R" 103 The chain-like alkenyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0210] R" 104The fluorinated alkyl group in is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched perfluoroalkyl group having 1 to 5 carbon atoms, and even more preferably a nonafluorobutyl group.

[0211] • Anion in component (b-2) In formula (b-2), R 104 , R 105 Each of these is independently 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 them is R in formula (b-1). 101 Similar examples can be given. However, R 104 , R 105 These may be bonded to each other to form a ring. R 104 , R 105 The alkyl group is preferably a linear alkyl group which may have substituents, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. 104 , R 105 The number of carbon atoms in the chain-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. 104 , R 105 In the chain-like alkyl group, a higher number of hydrogen atoms substituted with fluorine atoms is preferable because it increases the acid strength and improves transparency to high-energy light and electron beams below 250 nm. The proportion of fluorine atoms in the chain-like alkyl group, i.e., the fluorination rate, is preferably 70-100%, more preferably 90-100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). 101 Similar examples include the above. In formula (b-2), L 101 , L 102 Each of these is either a single bond or an oxygen atom, independently of the others.

[0212] • Anion in component (b-3) In formula (b-3), R 106 ~R 108 Each of these is independently 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 them is R in formula (b-1). 101 Similar examples include the above. In formula (b-3), L 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-.

[0213] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B). Among these, 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-2) is particularly preferred.

[0214] {cation part} In the above equations (b-1), (b-2), and (b-3), M m+ This represents an onium cation with an m-valence. Among these, sulfonium cations and iodonium cations are preferred. m is an integer greater than or equal to 1.

[0215] Preferred cation portion ((M m+ ) 1 / m Examples of organic cations include those represented by the following general formulas (ca-1) to (ca-5).

[0216] Among the above, the cation part ((Mm+ ) 1 / m The cation represented by the general formula (ca-1) is preferred.

[0217] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 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. 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. 201 This represents -C(=O)- or -C(=O)-O-. 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. x is either 1 or 2. W 201 This represents a (x+1) valence linking group.

[0218] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 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 , and R 211 ~R 212 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R201 ~R 207 , and R 211 ~R 212 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the general formulas (ca-r-1) to (ca-r-7) above.

[0219] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 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, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyine ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

[0220] R 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. If an alkyl group is formed, it may bond with other elements to form a ring.

[0221] 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 this context, the SO2-containing cyclic group which may have substituents is preferably a "-SO2-containing polycyclic group," and more preferably a group represented by the general formula (b5-r-1).

[0222] Y 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the above formula (b-1) is R 101 An example of an aromatic hydrocarbon group in this context is the aryl group exemplified above, with one hydrogen atom removed. Y 201 The alkylene group and alkenylene group in the above formula (b-1) are R 101 Examples of the chain-like alkyl groups and chain-like alkenyl groups mentioned above include groups obtained by removing one hydrogen atom from the exemplified groups.

[0223] In the above equation (ca-4), x is either 1 or 2. W 201 This is a (x+1) valence, i.e., a divalent or trivalent linking group. W 201 In this, the divalent linking group is preferably a divalent hydrocarbon group which may have substituents, and Lz in the general formula (z-1) described later. 1 Examples of divalent hydrocarbon groups that may have substituents, similar to the above, can be given. 201The divalent linking group in this compound may be linear, branched, or cyclic, with cyclic being preferred. Among these, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of arylene groups include phenylene groups and naphthylene groups, with phenylene groups being particularly preferred. W 201 The trivalent linking group in is the aforementioned W 201 Examples include a group obtained by removing one hydrogen atom from a divalent linking group, and a group in which another divalent linking group is bonded to the aforementioned divalent linking group. 201 In this compound, a trivalent linking group is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0224] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0225] [ka]

[0226] [ka]

[0227] [ka] [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 0 to 20.]

[0228] [ka]

[0229] [ka]

[0230] [ka] [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 ~R 212 These are the same substituents that may be present.

[0231] Suitable cations represented by the formula (ca-2) include, specifically, diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0232] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0233] [ka]

[0234] Specific examples of suitable cations represented by the above formula (ca-4) include the cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0235] [ka]

[0236] Specific examples of suitable cations represented by the above formula (ca-5) include the cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0237] [ka]

[0238] Among the above, the cation part ((M m+ ) 1 / mThe cation represented by the general formula (ca-1) is preferred.

[0239] In this embodiment, component (B1) preferably contains an acid generator (B1-1) represented by the following general formula (b1-1).

[0240] [ka] [In the formula, Rb 201 ~Rb 203 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~R 203 These may bond to each other to form a ring with the sulfur atom in the formula. - It is an anti-anion.

[0241] In the above formula (b1-1), Rb 201 ~Rb 203 R in the above formula (ca-1) is 201 ~R 203 It is similar to that. In particular, Rb 201 ~Rb 203 However, each may independently have a substituent on an aryl group, or Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is preferable that they bond to each other and form a ring together with the sulfur atom in the formula, Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is more preferable that they bond to each other and form a ring with the sulfur atom in the formula, Rb 201 Rb is an aryl group which may have substituents. 202 and Rb 203 It is even more preferable that these atoms bond to each other to form a tetrahydrothiophenium ring or a tetrahydrothiopyranium ring together with the sulfur atom in the formula.

[0242] In the above formula (b1-1), X -The counter anions in are preferably the anion of component (b-1), the anion of component (b-2), and the anion of component (b-3), more preferably the anion of component (b-1), even more preferably an anion represented by any of the formulas (an-1) to (an-4), and even more preferably an anion represented by formula (an-1) or (an-4).

[0243] In the resist composition of this embodiment, component (B1) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (B1) is preferably 50 parts by mass or less, more preferably 0.1 to 40 parts by mass, even more preferably 0.1 to 30 parts by mass, and particularly preferably 0.1 to 20 parts by mass, per 100 parts by mass of component (A1). (B1) By setting the content of component B1 within the above preferred 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 because it results in good storage stability for the resist composition.

[0244] <Optional ingredients> ≪(D) ​​Component≫ The resist composition in this embodiment may further contain an acid diffusion control agent component (hereinafter referred to as "component (D)"). Component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of component (D) include nitrogen-containing organic compounds (D1) (hereinafter referred to as "component (D1)") and photodegradable bases (D2) that do not fall under component (D1) and decompose upon exposure, losing their acid diffusion control properties (hereinafter referred to as "component (D2)"). (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. As for component (D), component (D1) is preferred from the viewpoint of improving the transmittance of the resist film to the exposure light source when forming a thick resist pattern.

[0245] • About the (D1) component Component (D1) is a basic component, a nitrogen-containing organic compound component that acts as an acid diffusion control agent in the resist composition.

[0246] The (D1) component is not particularly limited as long as it acts as an acid diffusion control agent, and examples include aliphatic amines and aromatic amines.

[0247] Among aliphatic amines, secondary and tertiary aliphatic amines are preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 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 or 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.

[0248] 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 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.

[0249] 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.

[0250] Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, trimenzylamine, aniline compounds such as 2,6-diisopropylaniline, 2,6-di-tert-butylpyridine, and N-tert-butoxycarbonylpyrrolidine.

[0251] (D1) Component may be used alone or in combination of two or more types. The (D1) component is preferably an alkylamine or an aromatic amine among the above, more preferably an alkylamine, and even more preferably a trialkylamine having 6 to 30 carbon atoms. If the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.001 to 10 parts by mass, more preferably 0.002 to 1 part by mass, and even more preferably 0.005 to 0.1 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 shapes are easily obtained. On the other hand, when it is below the upper limit, a balance with other components can be achieved, resulting in good lithography characteristics across various categories.

[0252] • About the (D2) component The (D2) component is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of the compound represented by the following general formula (d2-1) (hereinafter referred to as "component (d2-1)"), the compound represented by the following general formula (d2-2) (hereinafter referred to as "component (d2-2)"), and the compound represented by the following general formula (d2-3) (hereinafter referred to as "component (d2-3)"). Components (d2-1) to (d2-3) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), so they do not act as a quencher, but they act as a quencher in the unexposed areas of the resist film.

[0253] [ka] [In the formula, Rd 1 ~Rd 4 Rd in general formula (d2-2) 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. 2 In this example, assume that no fluorine atoms are bonded to carbon atoms adjacent to the sulfur atom. 1 is a single bond or a divalent linking group. m is an integer greater than or equal to 1, and M' m+ These are each independently m-valent onium cations.

[0254] {(d2-1) component} · Anion Club In formula (d2-1), Rd 1 R in formula (b-1) 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 these is R 101 Examples include those similar to the above. Among these, Rd 1 Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), 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 the linking groups represented by the general formulas (y-al-1) to (y-al-5). Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (for example, a polycyclic structure consisting of a bicyclooctane skeleton ring structure 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, tricyclodecane, or tetracyclododecane. The linear alkyl group preferably has 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.

[0255] When the chain-like alkyl group is a fluorinated alkyl group having a fluorinated 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 the like. Rd 1 Preferably, the linear alkyl group is a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and particularly preferably, the linear alkyl group is a fluorinated alkyl group (linear perfluoroalkyl group) in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms.

[0256] The following are some preferred specific examples of the anionic portion of component (d2-1).

[0257] [ka]

[0258] • Cation section In formula (d2-1), M' m+ This is an onium cation with an oval value. M' m+ Suitable onium cations include those similar to those represented by the general formulas (ca-1) to (ca-4), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-78) and (ca-1-101) to (ca-1-149) being even more preferred. (d2-1) Component may be used alone or in combination of two or more types.

[0259] {(d2-2) component} · Anion Club In formula (d2-2), Rd 2R in formula (b-1) 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. 101 Examples include those similar to the above. However, Rd 2 In this example, the carbon atom adjacent to the S atom is assumed to be unbonded to a fluorine atom (not fluorine-substituted). This results in the (d2-2) component anion becoming a moderately weak acid anion, improving the quenching ability of the (D2) component. Rd 2 Preferably, 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 carbon atoms. The aliphatic cyclic group preferably has one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclodecane, 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 (d2-1). 1 Examples of substituents that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above are similar to those mentioned above.

[0260] The following are some preferred specific examples of the anionic portion of component (d2-2).

[0261] [ka]

[0262] • Cation section In formula (d2-2), M' m+ This is an m-valent onium cation, and M' in formula (d2-1) above. m+ It is similar to that. (d2-2) Component (d2-2) may be used individually or in combination of two or more components.

[0263] {(d2-3) component} · Anion Club In formula (d2-3), Rd 3 R in formula (b-1) 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. 101 Examples include those similar to the above, and it is preferable that they are cyclic groups containing a fluorine atom, linear alkyl groups, or linear alkenyl groups. Among these, fluorinated alkyl groups are preferred, and the above Rd 1 A fluorinated alkyl group similar to the one shown is more preferable.

[0264] In formula (d2-3), Rd 4 R in formula (b-1) 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. 101 Examples include those similar to the above. In particular, alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents, are preferred. Rd 4 The alkyl group in 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. 4 Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include the methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, and tert-butoxy group. Among these, the methoxy group and ethoxy group are preferred.

[0265] Rd 4 The alkenyl group in formula (b-1) is R 101Examples include those similar to the above, with vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups being preferred. These groups may further have a C1-C5 alkyl group or a C1-C5 halogenated alkyl group as substituents.

[0266] Rd 4 The cyclic group in is R in formula (b-1) above. 101 Examples include those similar to the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or aromatic groups such as phenyl groups and naphthyl groups. 4 When the group is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties.

[0267] In formula (d2-3), Yd 1 It is a single bond or a divalent linking group. Yd 1 The divalent linking group in formula (a10-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. These are, respectively, Ya in formula (a10-1) above. x1 Examples include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in [reference]. Yd 1 The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0268] The following are preferred specific examples of the anionic portion of the (d2-3) components.

[0269] [ka]

[0270] [ka]

[0271] • Cation section In formula (d2-3), M' m+ This is an m-valent onium cation, and M' in formula (d2-1) above. m+ It is similar to that. (d2-3) Components may be used individually or in combination of two or more.

[0272] Component (D2) may consist of only one of the above components (d2-1) to (d2-3), or it may consist of a combination of two or more components. If the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.5 to 35 parts by mass, more preferably 1 to 25 parts by mass, even more preferably 2 to 20 parts by mass, and particularly preferably 3 to 15 parts by mass, per 100 parts by mass of component (A). When the content of component (D2) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shapes are easily obtained. On the other hand, when it is below the upper limit, a balance with other components can be achieved, resulting in good lithography characteristics across various categories.

[0273] (D2) Method for producing component: The methods for producing the aforementioned components (d2-1) and (d2-2) are not particularly limited and can be produced by known methods. Furthermore, the method for producing component (d2-3) is not particularly limited and may be, for example, the same as the method described in US2012-0149916.

[0274] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and their derivatives>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). Examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, among which salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred among these. Examples of derivatives of phosphorus oxoacids include esters obtained by substituting the hydrogen atoms of the above oxoacid with hydrocarbon groups, and examples of hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.

[0275] In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. If the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of component (A). By setting the content within the above range, the lithography characteristics are further improved.

[0276] ≪Fluorine additive component (F)≫ The resist composition in this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as the hydrophobic resin. Component (F) is used to impart water repellency to the resist film and, by being used as a separate resin from component (A), improves lithography properties. As component (F), for example, fluorine-containing polymer compounds 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 can be used. More specifically, component (F) includes polymers having a constituent unit (f1) represented by the following general formula (f1-1). This polymer is preferably a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, and more preferably a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0277] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 They may be the same or different. 1 Rf is an integer between 0 and 5. 101 It is an organic group containing a fluorine atom.

[0278] In formula (f1-1), R bonded to the α-carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 A fluorine atom is preferred as the halogen atom. Rf 102 and Rf 103 Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. 102 and Rf 103 Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. 102 and Rf 103 Preferably, the element is a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms; more preferably, a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group; and even more preferably, a hydrogen atom. In formula (f1-1), nf 1 is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0279] In formula (f1-1), Rf 101 This is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing fluorine atoms may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, in hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101More preferably, fluorinated hydrocarbon groups having 1 to 6 carbon atoms are used, with trifluoromethyl groups, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, and -CH2-CH2-CF2-CF2-CF2-CF3 being particularly preferred.

[0280] 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 it is below the upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. 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.

[0281] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. If the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A).

[0282] ≪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 can be appropriately selected from those conventionally known as solvents for chemically amplified resist compositions. (S) components include, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyhydric alcohols or compounds having ester bonds; etc. Examples include derivatives of polyhydric alcohols [of which propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). 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.

[0283] 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 of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2. More specifically, when EL or cyclohexanone is used as the polar solvent, the mass ratio of PGMEA to EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is used as the polar solvent, the mass ratio of PGMEA to PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. 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.

[0284] The amount of component (S) used is not particularly limited in terms of the solid content concentration of the resist composition, but is preferably 15 to 60% by mass, more preferably 20 to 55% by mass, even more preferably 25 to 50% by mass, and still more preferably 30 to 50% by mass. In this specification, the solid content in a resist composition refers to components other than component (S). The solid content concentration of the resist composition is calculated by the following formula. Solid content concentration (mass%) = Total mass of components other than (S) / Total mass of resist composition × 100

[0285] For example, if the resist composition consists of components (A), (Z), (B), (D), and (S), the solid content concentration (mass%) = [((A) component + (Z) component + (B) component + (D) component) / ((A) component + (Z) component + (B) component + (D) component) + (S) component] × 100.

[0286] By setting the solid content concentration of the resist composition within the above preferred range, a thick resist film (for example, with a film thickness of 2 μm to 20 μm) can be formed when the resist composition is applied to a substrate to form a resist film. The solid content concentration of the resist composition can be appropriately determined according to the desired film thickness of the resist film. Generally, the higher the solid content concentration, the thicker the resist film becomes.

[0287] The resist composition of this embodiment may further contain, if desired, miscible additives such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc.

[0288] The resist composition of this embodiment may be subjected to removal of impurities after dissolving the resist material in component (S), using a polyimide porous membrane, a polyamide-imide porous membrane, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous membrane, a filter made of a polyamide-imide porous membrane, or a filter made of a polyimide porous membrane and a polyamide-imide porous membrane. Examples of the polyimide porous membrane and the polyamide-imide porous membrane include those described in Japanese Patent Application Publication No. 2016-155121.

[0289] The resist composition of this embodiment described above contains a constituent unit (a1) having an acid-degradable group whose polarity increases by the action of an acid, a constituent unit (a10) represented by the general formula (a10-1), a resin component (A1) having a constituent unit (a5) represented by the general formula (a5-1), and a resin component (Z) having a constituent unit (z1) represented by the general formula (z1-1) and not containing an acid-dissociable group. In thick resist films, cracks are more likely to occur in the resist pattern. Furthermore, with thick resists, the exposure light source may not reach the bottom of the resist film, leading to a larger difference in CD (ΔCD) between the top and bottom of the pattern, thus reducing the rectangularity of the pattern shape. Additionally, increasing the thickness of the resist can increase viscosity, potentially reducing handling properties. The resist composition of this embodiment contains component (A1), which enhances the light transmittance of thick resist films. As a result, even when forming thick resist films, sensitivity is increased, resolution is improved, ΔCD is reduced, and a resist pattern with a good shape can be formed. Furthermore, by including component (Z) in the resist composition of this embodiment, the viscosity of the resist composition can be controlled to a range that provides good crack resistance and good handling properties. Furthermore, it is presumed that the resist composition of this embodiment is less susceptible to process influences during pattern formation due to the combined effects of components (A1) and (Z).

[0290] (Method for forming resist patterns) A resist pattern formation method according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, 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.

[0291] First, the resist composition of the above-described 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 60 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 ArF 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 this, a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 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.

[0292] 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.

[0293] 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.

[0294] The resist pattern formation method of this embodiment is useful when forming a thick resist film. Even if the thickness of the resist film formed by coating the resist composition onto the substrate is, for example, 5 to 20 μm, a resist pattern can be stably formed in a good shape.

[0295] The wavelength used for exposure is not particularly limited, and the process can be carried out using 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 KrF excimer lasers, ArF excimer lasers, EB, or EUV, and is even more useful for ultraviolet light such as g-rays and i-rays, KrF excimer laser light, and ArF excimer laser light, and is particularly useful for ultraviolet light such as g-rays and i-rays, and KrF excimer laser light. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film involves irradiating the resist film with ultraviolet light such as g-rays and i-rays, or KrF excimer laser light.

[0296] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. 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. Examples include water, fluorinated inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the immersion medium.

[0297] 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. Ketone solvents are organic solvents that contain CC(=O)-C in their structure. Ester solvents are organic solvents that contain CC(=O)-OC in their structure. Alcohol solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. An "alcoholic hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents that contain a nitrile group in their structure. Amide solvents are organic solvents that contain an amide group in their structure. Ether solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple functional groups in their structure that characterize each of the above-mentioned solvents. In such cases, the organic solvent shall be considered to belong to any of the solvent categories that contain the functional groups it possesses. For example, diethylene glycol monomethyl ether shall belong to either the alcohol-based solvent or the ether-based solvent category in the above classification. Hydrocarbon solvents consist of hydrocarbons that may be halogenated and do not have substituents other than halogen atoms. Fluorine atoms are preferred as the halogen atom. Among the above, polar solvents are preferred as organic solvents contained in organic developers, and ketone solvents, ester solvents, nitrile solvents, etc., are preferred.

[0298] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, and methyl amyl ketone (2-heptanone). Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0299] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethyl ethoxyethyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl 4-Ethoxybutyl acetate, 4-Propoxybutyl acetate, 2-Methoxypentyl acetate, 3-Methoxypentyl acetate, 4-Methoxypentyl acetate, 2-Methyl-3-Methoxypentyl acetate, 3-Methyl-3-Methoxypentyl acetate, 3-Methyl-4-Methoxypentyl acetate, 4-Methyl-4-Methoxypentyl acetate, Propylene glycol diacetate, Methyl formate, Ethyl formate, Butyl formate, Propyl formate, Ethyl lactate, Butyl lactate, Propyl lactate Examples include butyl acetate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

[0300] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0301] 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. Nonionic surfactants are preferred, with nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0302] The development process can be carried out by known development methods, such as immersing the support in a developer solution for a certain period of time (dip method), piling the developer solution onto the surface of the support using surface tension and leaving it still for a certain period of time (paddle method), spraying the developer solution onto the surface of the support (spray method), or continuously dispensing the developer solution onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0303] As for the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that do not easily dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinsing solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and this monohydric alcohol may be linear, branched, or cyclic. Specifically, examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used individually or in combination of two or more. They may also be mixed with other organic solvents or water. However, considering the developing characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, relative to the total volume of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants are the same as those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total volume of the rinse solution.

[0304] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying 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).

[0305] According to the resist pattern formation method of this embodiment described above, since the resist composition described above is used, the pattern formation is less susceptible to process influences, crack occurrence is reduced, and a thick-film resist pattern with a good shape can be formed.

[0306] This resist pattern formation method is useful for manufacturing three-dimensional structural devices and is suitable for applications involving the processing of multi-stage stepped structures (such as superposition). By applying the resist pattern formation method of the present invention, high-precision stacking of memory films (three-dimensional stacking, manufacturing of large-capacity memory) can be achieved.

[0307] 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). [Examples]

[0308] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0309] <Preparation of the resist composition> (Examples 1-46, Comparative Examples 1-22) Each of the components shown in Tables 1-6 was mixed and dissolved to prepare a resist composition (solid content concentration: 45%) for each example.

[0310] [Table 1]

[0311] [Table 2]

[0312] [Table 3]

[0313] [Table 4]

[0314] [Table 5]

[0315] [Table 6]

[0316] In Tables 1-6, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A)-1: A polymer compound represented by the following chemical formula (A-1). This polymer compound (A-1) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-1), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 30 / 25.

[0317] [ka]

[0318] (A)-2: A polymer compound represented by the following chemical formula (A-2). This polymer compound (A-2) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-2), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 55 / 25.

[0319] [ka]

[0320] (A)-3: A polymer compound represented by the following chemical formula (A-3). This polymer compound (A-3) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-3), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 50 / 25 / 25.

[0321] [ka]

[0322] (A)-4: A polymer compound represented by the following chemical formula (A-4). This polymer compound (A-4) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-4), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 50 / 25 / 25.

[0323] [ka]

[0324] (A)-5: A polymer compound represented by the following chemical formula (A-5). This polymer compound (A-5) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-5), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 45 / 35.

[0325] [ka]

[0326] (A)-6: A polymer compound represented by the following chemical formula (A-6). This polymer compound (A-6) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-6), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 35 / 25.

[0327] [ka]

[0328] (A)-7: A polymer compound represented by the following chemical formula (A-7). This polymer compound (A-7) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-7), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 35 / 25.

[0329] [ka]

[0330] (A)-8: A polymer compound represented by the following chemical formula (A-8). This polymer compound (A-8) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-8), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 50 / 25 / 25.

[0331] [ka]

[0332] (A)-9: A polymer compound represented by the following chemical formula (A-9). This polymer compound (A-9) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-9), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 45 / 35.

[0333] [ka]

[0334] (A)-10: A polymer compound represented by the following chemical formula (A-10). This polymer compound (A-10) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-10), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 35 / 25.

[0335] [ka]

[0336] (A)-11: A polymer compound represented by the following chemical formula (A-11). This polymer compound (A-11) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-11), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 30 / 45 / 25.

[0337] [ka]

[0338] (A)-12: A polymer compound represented by the following chemical formula (A-12). This polymer compound (A-12) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-12), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 55 / 25.

[0339] [ka]

[0340] (A)-13: A polymer compound represented by the following chemical formula (A-13). This polymer compound (A-13) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-13), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 45 / 35.

[0341] [ka]

[0342] (A)-14: A polymer compound represented by the following chemical formula (A-14). This polymer compound (A-14) was obtained by radical polymerization using monomers that induce the constituent units of the polymer compound in a predetermined molar ratio. For this polymer compound (A-14), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 1.90. 13The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 20 / 45 / 35.

[0343] [ka]

[0344] (B)-1: An acid generator consisting of a compound represented by the following chemical formula (B-1). (D)-1: A nitrogen-containing organic compound consisting of the compound represented by the following chemical formula (D-1).

[0345] [ka]

[0346] (Z)-1-1: A compound represented by the chemical formula (Z-1) shown below. For this compound (Z-1-1), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 40,000, and the molecular weight dispersion (Mw / Mn) is 4.00. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-1-2: A compound represented by the chemical formula (Z-1) shown below. For this compound (Z-1-2), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 80,000, and the molecular weight dispersion (Mw / Mn) is 5.10. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-1-3: A compound represented by the chemical formula (Z-1) shown below. For this compound (Z-1-3), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 200,000, and the molecular weight dispersion (Mw / Mn) is 8.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-1-4: A compound represented by the chemical formula (Z-1) shown below. For this compound (Z-1-4), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.00. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-1-5: A compound represented by the chemical formula (Z-1) shown below. For this compound (Z-1-5), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2000, and the molecular weight dispersion (Mw / Mn) is 1.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15.

[0347] (Z)-2-1: A compound represented by the chemical formula (Z-2) shown below. For this compound (Z-2-1), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 40,000, and the molecular weight dispersion (Mw / Mn) is 4.00. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-2-2: A compound represented by the chemical formula (Z-2) shown below. For this compound (Z-2-2), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 80,000, and the molecular weight dispersion (Mw / Mn) is 5.10. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-2-3: A compound represented by the chemical formula (Z-2) shown below. For this compound (Z-2-3), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 200,000, and the molecular weight dispersion (Mw / Mn) is 8.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-2-4: A compound represented by the chemical formula (Z-2) shown below. For this compound (Z-2-4), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 10,000, and the molecular weight dispersion (Mw / Mn) is 2.00. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15. (Z)-2-5: A compound represented by the chemical formula (Z-2) shown below. For this compound (Z-2-5), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 2000, and the molecular weight dispersion (Mw / Mn) is 1.50. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15.

[0348] (Z)-3: A compound represented by the chemical formula (Z-3) shown below. For this compound (Z-3), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, is 40,000, and the molecular weight dispersion (Mw / Mn) is 4.00. 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m / n = 40 / 45 / 15.

[0349] [ka]

[0350] (S)-1: Propylene glycol monomethyl ether acetate (PGMEA) (S)-2: Propylene glycol monomethyl ether (PGME) (S)-3: Butyl acetate

[0351] <Resist pattern formation> Process (i): Each example of the resist composition was applied to a silicon wafer treated with hexamethyldisilazane (HMDS) at 110°C for 60 seconds using a spinner. A post-applied bake (PAB) treatment was performed on a hot plate at 140°C for 90 seconds, followed by drying to form a resist film with a thickness of 18 μm.

[0352] Step (ii): Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern (binary mask) using a KrF exposure system NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ = 0.68). Next, a post-exposure heating (PEB) treatment was performed at 120°C for 90 seconds.

[0353] Step (iii): Next, alkaline development was performed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as the developer, at 23°C for 60 seconds. As a result, an isolated space pattern (IS pattern) with a space width of 5 μm was formed.

[0354] [Crack evaluation] The substrate on which the IS pattern was formed as described above in <Formation of Resist Pattern> was placed in the chamber of a scanning electron microscope S-9380 (manufactured by Hitachi High-Technologies Corporation) and subjected to vacuum treatment for 60 seconds under a pressure of 0.0001 Pa. The silicon wafer after vacuum treatment was observed using an optical microscope, and the number of cracks was counted. The number of cracks was evaluated based on the evaluation criteria below. The results are shown as "cracks" in Tables 7 to 12. Evaluation Criteria A: 0 cracks B: 1-5 cracks C: 6-20 cracks D: 21 or more cracks

[0355] [ΔCD shape evaluation] For the IS pattern formed in the above <Formation of Resist Pattern>, the CD-top and CD-bottom lengths of the pattern were measured using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation), and the difference (ΔCD) was calculated. A smaller ΔCD value indicates higher rectangularity of the pattern and the formation of a well-shaped pattern. The results are shown as "ΔCD shape (μm)" in Tables 7-12.

[0356] [Viscosity evaluation] The viscosity (cP) of each resist composition was measured using an automatic viscosity analyzer VMC-252 (manufactured by Rigo Co., Ltd.). The measured viscosity was evaluated based on the following evaluation criteria. The results are shown as "viscosity" in Tables 7 to 12. Evaluation Criteria A: Less than 500 cP B: 500 cP or more but less than 600 cP C:600cP or more

[0357] [Evaluation of CD changes after exposure and storage] In step (ii) of the above-described <Formation of Resist Pattern>, the IS pattern was formed in the same manner as in the above-described <Formation of Resist Pattern>, except that after selective exposure of the resist film with a KrF excimer laser, a 2-hour settling period was followed by a post-exposure heating (PEB) treatment at 120°C for 90 seconds. The formed IS patterns were measured using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation), and the CD difference (hereinafter also referred to as "CD(PED) value") due to the post-exposure setting time was calculated. The calculated CD(PED) values ​​were evaluated based on the following evaluation criteria. A smaller CD(PED) value indicates a better resist, as it is less susceptible to process-induced CD changes. The results are shown as "CD(PED)" in Tables 7-12. Evaluation Criteria A: CD(PED) < 50nm B: 50nm ≤ CD(PED) < 150nm C: 150nm ≤ CD(PED) ≤ 500nm D:CD(PED)>500nm

[0358] [Table 7]

[0359] [Table 8]

[0360] [Table 9]

[0361] [Table 10]

[0362] [Table 11]

[0363] [Table 12]

[0364] The results shown in Tables 7-12 confirm that all of the resist compositions in the examples had a viscosity of 500 cP or less. Furthermore, the thick-film resist patterns formed using the resist compositions in the examples showed a small ΔCD, reduced crack occurrence, and good CD(PED).

[0365] While preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications are possible without departing from the spirit of the invention. The present invention is not limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, A resin component (A1) having a constituent unit (a1) containing an acid-degradable group whose polarity increases upon the action of an acid, a constituent unit (a10) represented by the following general formula (a10-1), and a constituent unit (a5) represented by the following general formula (a5-1), A resist composition containing a resin component (Z) which has a constituent unit (z1-1-1) represented by the following general formula (z1-1-1) and a constituent unit (z1-1-21) represented by the following general formula (z1-1-21), and which does not contain an acid-dissociable group. 【Chemistry 1】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ya ｘ１ Wa is a single bond or a divalent linking group. ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.] 【Chemistry 2】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ra ５ This is an acid-nondissociable aliphatic cyclic group in which some of the carbon atoms forming the ring skeleton may be substituted with oxygen atoms. 【Transformation 3】 [In the formula, R 01 is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Vz 01 is a single bond, -C(=O)-O-Y 21- or -C(=O)-O-Y 21-O-C(=O)-Y 22-. Y 21 and Y 22 are each independently divalent hydrocarbon groups which may have substituents, and O is an oxygen atom. However, if Vz 01 is -C(=O)-O-Y 21- or -C(=O)-O-Y 21-O-C(=O)-Y 22-, Vz 01 does not contain an acid-dissociable group.] 【Chemistry 4】 [In the formula, R 21 is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Rz 11 is a linear alkylene group. Rz 12 is a linear alkyl group.]

2. The resist composition according to claim 1, wherein the content of the resin component (Z) is 1 to 50 parts by mass per 100 parts by mass of the resin component (A1).

3. The resist composition according to claim 1 or 2, wherein the weight-average molecular weight of the resin component (Z) is 20,000 to 100,000.

4. The resist composition according to claim 1 or 2, wherein the proportion of the constituent unit (a10) in the resin component (A1) is 15 to 60 mol% with respect to the total amount (100 mol%) of all constituent units that make up the resin component (A1).

5. 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; exposing the resist film; and developing the exposed resist film to form a resist pattern.

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