Chemically amplified positive resist composition and resist pattern forming process

Abstract

This invention provides a chemically amplified positive resist composition containing an onium salt capable of generating an acid with low diffusion, and a method for forming a resist pattern using the resist composition. A chemically amplified positive resist composition comprises: (A) a photoacid generator composed of an onium salt represented by formula (A); and (B) a base polymer comprising a polymer containing repeating units represented by formula (B1) and exhibiting increased solubility in an alkaline developer upon decomposition under acid. In the formula, one of R13 and R14 is a base having a substructure shown in formula (a).

Description

Technical Field

[0001] This invention relates to chemically amplified positive inhibitor compositions and methods for forming inhibitor patterns. Prior Technology

[0002] In recent years, with the increasing integration of integrated circuits, there is a demand for forming finer patterns. In the processing of patterns below 0.2 μm, chemically amplified resist compositions using acid as a catalyst are mainly used. In this case, high-energy rays such as UV rays, far-ultraviolet rays, and electron beams (EB) are used as exposure sources, and in particular, EB lithography, used for ultra-fine processing, is an essential method for processing blank photomasks for manufacturing photomasks. As resist compositions used in such lithography methods, there are positive types that form patterns by dissolving the exposed areas and negative types that form patterns by leaving the exposed areas. The choice of resist composition depends on the desired shape of the resist pattern and is based on ease of use.

[0003] Generally, EB (Extended Electrode) mapping does not use a mask. In positive cases, a method is used where a fine-area EB is sequentially used to illuminate the areas excluding the region where the resist film will remain. In negative cases, the region where the resist film will remain is sequentially illuminated. This is a scanning operation performed on the entire area of ​​the processed surface that is finely divided. Therefore, it takes longer than simultaneous exposure using a photomask, and to maintain productivity, the resist film must have high sensitivity. Furthermore, due to the long mapping time, differences can easily arise between the early and late mapped areas; the time-stability of the exposed areas in a vacuum is an important performance requirement. Furthermore, in the processing of blank photomasks, which is of particular importance, there are blank photomasks with surface materials that can easily affect the pattern shape of chemically amplified resist films such as chromium compound films, represented by chromium oxide, which are formed on the photomask substrate. In order to maintain high resolution and the etched shape, it is also important to maintain the pattern outline of the resist film as a rectangle regardless of the type of substrate.

[0004] The sensitivity and pattern profile control of the aforementioned resist films have been improved in various ways depending on the selection and combination of materials used in the resist composition and processing conditions. One such improvement is the problem of acid diffusion, which significantly affects the resolution of chemically amplified resist films. In photomask processing, it is required that the shape of the obtained resist pattern does not change depending on the time until post-exposure heating (PEB), but the main reason for time-dependent changes is the diffusion of acid generated during exposure. This acid diffusion problem is not limited to photomask processing; it also has a significant impact on sensitivity and resolution in general resist compositions, thus requiring extensive research.

[0005] Patent Documents 1 and 2 describe examples of suppressing acid diffusion and reducing roughness by increasing the volume of acid generated by the acid-generating agent. However, in such acid-generating agents, the suppression of acid diffusion is not sufficient, and therefore it is desirable to develop acid-generating agents with smaller diffusion.

[0006] Furthermore, Patent Document 3 describes an example of controlling acid diffusion by bonding the sulfonic acid generated by exposure to a polymer used in the inhibitor composition. This method of suppressing acid diffusion by bonding the repeating units that generate acid through exposure to the base polymer is effective for obtaining patterns with low line edge roughness (LER). However, depending on the structure and incorporation rate of such repeating units, there are also issues with the solubility of the base polymer to which the repeating units generated by exposure are bonded in organic solvents.

[0007] However, polymers with a large number of aromatic backbones with acidic side chains, such as polyhydroxystyrene, are useful as resist compositions for KrF lithography, but are not used as materials for ArF lithography resist compositions due to their large absorption of light around 200 nm. However, EB lithography resist compositions and extreme ultraviolet (EUV) lithography resist compositions, as powerful techniques for forming patterns with smaller processing limits than ArF lithography, are important materials for achieving high etch resistance.

[0008] The base polymers used in positive EB lithography and EUV lithography resist compositions primarily employ materials that are soluble in alkaline developers. These polymers utilize acid generated by a photoacid generator through high-energy irradiation as a catalyst to deprotect acid-indestructible groups (acid-decomposing protecting groups) that mask the acidic functional groups of the phenolic side chains in the base polymer. Furthermore, tertiary hydrocarbon groups, tertiary butyryloxycarbonyl groups, and acetal groups are commonly used as these acid-indestructible groups. Using protecting groups with relatively low activation energies for deprotection, such as acetal groups, offers the advantage of obtaining highly sensitive resist films. However, if the diffusion of the generated acid is not sufficiently suppressed, the following problems arise: deprotection reactions can also occur in the unexposed portions of the resist film, leading to deterioration of the LER (Linear Emission Reduction) and a decrease in the in-plane uniformity (CDU) of the pattern linewidth.

[0009] Furthermore, patent documents 4 and 5 propose photoacid generators that produce non-fluorinated aromatic sulfonic acids with multiple large alkyl substituents. By utilizing multiple alkyl substituents to increase the molecular weight of the generated acid, acid diffusion is reduced. However, when the purpose is to form fine patterns, the suppression of acid diffusion is still insufficient, leaving room for further improvement.

[0010] Furthermore, in the formation of fine patterns using EB lithography, the shape of the resist pattern becomes a backward-pulled shape due to the backscattering effect of reflections from the EB to the substrate. This backward-pulled shape induces resist pattern collapse during development. To address the requirements for further miniaturization, it is desirable to develop a photoacid-generating agent that solves the above problems, corrects the pattern shape, and suppresses acid diffusion. [Previous Technical Documents] [Patent Literature]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 2009-053518 [Patent Document 2] Japanese Patent Application Publication No. 2010-100604 [Patent Document 3] Japanese Patent Application Publication No. 2011-22564 [Patent Document 4] Japanese Patent No. 6248882 [Patent Document 5] Japanese Patent Application Publication No. 2019-202974 Summary of the Invention

[0012] [The problem the invention aims to solve] In recent years, there has been a demand for resist compositions that not only have excellent line-to-spacing (LS), isolated lines (IL), and isolated spacing (IS), but also excellent hole pattern shape. As for the acid generating agent described in Patent Document 4, which produces a large acid volume and inhibits acid diffusion, although it inhibits acid diffusion to a certain extent, the shape of the pattern becomes a backward-pulled shape when the fine pattern is formed, which has the problem of pattern collapse during development after alkaline development.

[0013] The present invention was made in view of the above circumstances, and its object is to provide a chemically amplified positive resist composition comprising an onium salt capable of producing an acid with low diffusion, and a method for forming a resist pattern using the resist composition. [Methods used to solve problems]

[0014] In order to achieve the above-mentioned objectives, the inventors have conducted repeated and in-depth research and found that onium salts containing sulfonic acid anions with substituent ring-condensing structures and aromatic sulfonic acid structures have excellent solvent solubility. When these salts are introduced into positive type inhibitor compositions as photoacid generators, patterns with small CDU and LER values ​​can be obtained. Furthermore, through appropriate solubility and inhibition, patterns with good rectangularity can be obtained, thus completing the present invention.

[0015] That is, the present invention provides the following chemically amplified positive inhibitor composition and inhibitor pattern formation method. 1. A chemically amplified positive inhibitor composition, comprising: (A) A photoacid generator composed of an onium salt represented by the following formula (A), and (B) A base polymer comprising repeating units represented by the following formula (B1) that decomposes under the action of acid and increases its solubility in alkaline developers. [Chemistry 1] In the formula, R1~R12 each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group with 1~20 carbon atoms that may also contain heteroatoms. One of R13 and R14 is a group having the substructure shown in formula (a) below, and the other is a hydrocarbon group with 1 to 20 carbon atoms, a hydrogen atom, a halogen atom, or may also contain heteroatoms. In addition, at least two of R1 to R14 can bond to each other and form a ring together with the carbon atoms they are bonded to, or with the carbon atoms they are bonded to and the carbon atoms between them. Z+ is an onium cation. [Chemistry 2] In the formula, m1 is 0 or 1, m2 is an integer from 0 to 4 when m1 is 0, and an integer from 0 to 6 when m1 is 1, m3 is an integer from 0 to 3 when m1 is 0, and an integer from 0 to 5 when m1 is 1. However, m2 + m3 is 0 to 4 when m1 is 0, and 0 to 6 when m1 is 1. RF is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. R15 can be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. When m3 is 2 or more, multiple R15 groups can bond to each other and form a ring together with the carbon atoms they are bonded to. LA and LB can be independently single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. XL is a single bond, or may contain heteroatoms and be an alkyl group with 1 to 40 carbon atoms. [Chemistry 3] In the formula, a1 is 0 or 1, a2 is an integer from 0 to 2, a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4, and a4 is an integer from 1 to 3. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R21 is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, or a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted by a halogen atom. A1 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group can also be replaced by -O-. 2. A chemically amplified positive inhibitor composition as described in 1, wherein the onium salt is represented by the following formula (A1), [Formula 4] In the formula, R1~R13, LA, XL, RF, R15, m1 to m3 and Z+ are as described above. 3. The chemically amplified positive inhibitor composition as described in 2, wherein the onium salt is represented by the following formula (A2), [Chemistry 5] In the formula, R5, R10~R13, R15, LA, XL, RF, m1 to m3 and Z+ are as described above. m4 and m5 are each independent integers from 0 to 4. R16 and R17 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. In addition, when m4 is 2 or more, multiple R16s can bond to each other and form a ring together with the carbon atoms they are bonded to, or together with the carbon atoms they are bonded to and the carbon atoms between them. When m5 is 2 or more, multiple R17s can bond to each other and form a ring together with the carbon atoms they are bonded to, or together with the carbon atoms they are bonded to and the carbon atoms between them. 4. An onium salt as described in any of 1.~3., wherein Z+ is a strontium cation as shown in formula (cation-1) or a monazite cation as shown in formula (cation-2). [Chemistry 6] In the formula, Rct1 to Rct5 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms containing heteroatoms. In addition, Rct1 and Rct2 may also be bonded to each other and form a ring together with the sulfur atoms they are bonded to. 5. A chemically amplified positive inhibitor composition as described in any one of 1. to 4, wherein the polymer further contains a repeating unit represented by the following formula (B2-1), [Chemistry 7] In the formula, RA represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. b1 is 0 or 1, b2 is an integer from 0 to 2, b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2b2 - b4, b4 is an integer from 1 to 3, and b5 is 0 or 1. R31 is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, or a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted by a halogen atom. A2 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms. Part of the -CH2- of this saturated alkyl group can also be replaced by -O-. X is an acid-labile group when b4 is 1, and a hydrogen atom or an acid-labile group when b4 is 2 or 3, but at least one of them is an acid-labile group. 6. A chemically amplified positive inhibitor composition as described in any one of 1. to 5, wherein the polymer further comprises a repeating unit as shown in formula (B2-2). [Chemistry 8] In the formula, c1 is an integer from 0 to 2, c2 is an integer from 0 to 2, c3 is an integer from 0 to 5, and c4 is an integer from 0 to 2. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R32 and R33 are each independently hydrocarbon groups with 1 to 10 carbon atoms, and may also contain heteroatoms. R32 and R33 can also bond with each other and form a ring together with the carbon atoms they are bonded to. R34 is independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms. R35 can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. A3 represents a single bond, phenyl, naphthyl, or *-C(=O)-O-A31-, where A31 is an aliphatic alkyl group with 1 to 20 carbon atoms that may contain a hydroxyl group, ether bond, ester bond, or lactone ring, or a phenyl or naphthyl group. * indicates an atomic bond with a carbon atom in the main chain. 7. A chemically amplified positive inhibitor composition as described in any one of 1. to 6, wherein the polymer contains at least one repeating unit selected from the repeating units represented by formula (B3), formula (B4), and formula (B5). [Chemistry 9] In the formula, d is an integer from 0 to 6, e is an integer from 0 to 4, f1 is 0 or 1, f2 is an integer from 0 to 2, and f3 is an integer from 0 to 5. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R41 and R42 are each independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. R43 can be a saturated hydrocarbon group with 1-20 carbon atoms, a saturated hydrocarbon oxygen group with 1-20 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2-20 carbon atoms, a saturated hydrocarbon oxy hydrocarbon group with 2-20 carbon atoms, a saturated hydrocarbon thioalkyl hydrocarbon group with 2-20 carbon atoms, a halogen atom, a nitro group, or a cyano group. When f2 is 1 or 2, it can be a hydroxyl group. A4 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms. Part of the -CH2- of this saturated alkyl group can also be replaced by -O-. 8. A chemically amplified positive inhibitor composition as described in any one of 1. to 7, wherein the polymer contains at least one repeating unit selected from the repeating units represented by formula (B6), formula (B7), formula (B8), and formula (B9). [Chemistry 10] In the formula, RA can be independently represented by a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X1 is a single bond or an extended phenyl group. X2 can be *1-C(=O)-O-X21-, *1-C(=O)-NH-X21-, or *1-O-X21-, where X21 is an aliphatic alkyl group, phenyl group, or a divalent group obtained by combining them, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. *1 is the atomic bond with X1. X3 can be a single bond, an enylphenyl group, an enylnaphthyl group, or *2-C(=O)-O-X31-, where X31 is an aliphatic enyl group, an enylphenyl group, or an enylnaphthyl group with 1 to 10 carbon atoms. This aliphatic enyl group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. *2 indicates an atomic bond with a carbon atom in the main chain. X4 can independently represent a single bond, *3-X41-C(=O)-O-, *3-C(=O)-NH-X41-, or *3-O-X41-, where X41 is a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms, and *3 represents an atomic bond with X3. X5 can independently represent a single bond, *4-X51-C(=O)-O-, *4-C(=O)-NH-X51-, or *4-O-X51-, where X51 is a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms, and *4 represents an atomic bond with X4. X6 represents a single bond, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *2-C(=O)-O-X61-, *2-C(=O)-N(H)-X61-, or *2-O-X61-, where X61 is an aliphatic phenyl group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or trifluoromethyl-substituted phenyl. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. *2 represents an atomic bond with a carbon atom in the main chain. R51 and R52 are each independently hydrocarbon groups with 1 to 20 carbon atoms, and may also contain heteroatoms. Furthermore, R51 and R52 can bond to each other and form a ring with the sulfur atoms they are bonded to. L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, carbonate bond, or carbamate bond. Rf1 and Rf2 are each independently either fluorine atoms or fluorinated saturated hydrocarbon groups having 1 to 6 carbon atoms. Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; however, not all Rf5 and Rf6 are simultaneously hydrogen atoms. M- is a non-nucleophilic opposite ion. A+ is an onium cation. g1 and g2 are each independent integers from 0 to 3. 9. A chemical amplification positive inhibitor composition as described in any one of 1. to 8, wherein the content of repeating units having an aromatic ring skeleton in all repeating units of the polymer contained in the base polymer is 60 mol% or more. 10. A chemically amplified positive inhibitor composition as described in any of 1. to 9, further comprising (C) an organic solvent. 11. The chemically amplified positive inhibitor composition of any one of 1. to 10. further comprises (D) a fluorinated polymer, the fluorinated polymer containing at least one repeating unit selected from the repeating units represented by formula (D1), formula (D2), formula (D3), and formula (D4) below, and may further contain at least one repeating unit selected from the repeating units represented by formula (D5) and formula (D6) below. [Chemistry 11] In the formula, j1 is an integer from 1 to 3, j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1, j3 is 0 or 1, and k is an integer from 1 to 3. Each of RB is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. RC can be independently represented by a hydrogen atom or a methyl group. R101, R102, R104, and R105 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R103, R106, R107, and R108 are each independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group with 1 to 15 carbon atoms, or an acid-unstable group. When R103, R106, R107, and R108 are hydrocarbon groups or fluorinated hydrocarbon groups, an ether bond or a carbonyl group can be inserted between the carbon-carbon bonds. R109 is a hydrogen atom, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have heteroatoms inserted between carbon-carbon bonds. R110 is a linear or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms can be inserted between carbon-carbon bonds. R111 is a saturated hydrocarbon group with 1 to 20 carbon atoms, in which at least one hydrogen atom is replaced by a fluorine atom. Part of the -CH2- of this saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. Z1 is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms. Z2 represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-, where * represents an atomic bond with a carbon atom in the main chain. Z3 represents a single bond, -O-, *-C(=O)-O-Z31-Z32- or *-C(=O)-NH-Z31-Z32-, where Z31 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, Z32 is a single bond, ester bond, ether bond or sulfonamide bond, and * is an atomic bond with a carbon atom in the main chain. 12. A chemical amplification positive inhibitor composition as described in any of 1. to 11, further comprising (E) a quencher. 13. A chemical amplification positive inhibitor composition as in 12, wherein the content ratio of (A) photoacid generator to (E) quencher is less than 3 by mass. 14. The chemical amplification positive inhibitor composition of claim 1 further contains a photoacid generator other than a photoacid generator composed of an onium salt represented by formula (A). 15. A method for forming a resist pattern, comprising: forming a resist film on a substrate using a chemically amplified positive resist composition as described in any one of 1. to 14; irradiating the resist film with a pattern using high-energy rays; and developing the irradiated resist film with an alkaline developer. 16. The resist pattern forming method of 15, wherein the high-energy ray is extreme ultraviolet light or an electron beam with a wavelength of 3 to 15 nm. 17. The resist patterning method of 15 or 16, wherein the outermost surface of the substrate is made of a chromium-containing material. 18. A method for forming a resist pattern as described in any one of 15 to 17, wherein the substrate is a blank photomask. [The effects of the invention]

[0016] The ononium salt represented by formula (A) is a chemically amplified positive resist component used as a photoacid generator. In microfabrication techniques, particularly in EB and EUV lithography, it exhibits extremely high resolution and can provide patterns with small LER (Lead-to-Rate) values. Furthermore, due to its moderate solubility-inhibiting properties, it can impart well-defined rectangular patterns, thus making it suitable as a chemically amplified positive resist material. Simple Explanation of the Diagram

[0017] Figure 1 shows the nuclear magnetic resonance spectrum (1H-NMR / DMSO-d6) of the onium salt PAG-1 synthesized in Synthesis Example 1-1. Implementation

[0018] The present invention will now be described in detail. It should be noted that, in the following description, the presence of asymmetric carbon according to the structure represented by the chemical formula may result in enantiomers and diastereomers; however, in this case, these isomers are representatively represented by a single formula. These isomers may be used individually or in mixtures of two or more.

[0019] [Chemical Amplification Positive Inhibitor Composition] The chemical amplification positive inhibitor composition of the present invention comprises (A) a photoacid generator consisting of an onium salt containing a sulfonic acid anion having a cyclic structure with substituents and an aromatic sulfonic acid structure, and (B) a base polymer containing a specified polymer.

[0020] [(A) Photoacid generator] The onium salt that is the photoacid generator of component (A) is represented by the following formula (A). [Chemistry 12]

[0021] In formula (A), R1 to R12 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms. One of R13 and R14 is a group having the substructure shown in formula (a) described later, and the other is a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms.

[0022] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. Among these, aryl groups are preferred. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the above-mentioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0023] Furthermore, at least two of R1 to R14 can bond to each other and form a ring together with the carbon atoms they are bonded to, or with the carbon atoms they are bonded to and the carbon atoms between them. Specific examples of the rings formed in this way include aliphatic rings such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornene, and adamantane, as well as aromatic rings such as benzene, naphthalene, and anthracene. Additionally, some or all of the hydrogen atoms in the above rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and part of the -CH2- group in the above rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, the rings may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. Aromatic rings are preferred, and benzene rings are more preferred.

[0024] In equation (A), either R13 or R14 is a basis having the substructure shown in equation (a) below. From a synthetic point of view, it is preferable that R14 is a basis having the substructure shown in equation (a) below. [Chemistry 13]

[0025] In formula (a), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. From a solubility point of view, a benzene ring with m1 of 0 is preferred. m2 is an integer from 0 to 4 when m1 is 0, and an integer from 0 to 6 when m1 is 1. It is preferred that m2 is 4 when m1 is 0, and 4, 5, or 6 when m1 is 1. m3 is an integer from 0 to 3 when m1 is 0, and an integer from 0 to 5 when m1 is 1. However, m2 + m3 is 0 to 4 when m1 is 0, and 0 to 6 when m1 is 1.

[0026] In formula (a), RF is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. RF is preferably a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio, or difluoromethylthio, and more preferably a fluorine atom, trifluoromethyl, or trifluoromethoxy. By using these groups containing or having fluorine atoms, the acid strength is increased through the electron-withdrawing effect, thus facilitating the deprotection reactions of unstable acid groups such as tertiary esters and tertiary ethers described later. When m2 is 2, 3, or 4, the RFs can be the same or different from each other.

[0027] In formula (a), R15 is a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be given of the same groups as those exemplified with respect to the hydrocarbon group represented by R1, but are not limited to these. When m3 is 2 or more, each R15 may be the same or different from the others. Furthermore, when m3 is 2 or more, multiple R15s may also bond to each other and form a ring together with the carbon atoms to which they are bonded. Preferably, the ring is a 5- to 8-membered ring.

[0028] In formula (a), LA and LB are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, single bonds, ether bonds, or ester bonds are preferred.

[0029] In formula (a), XL is a single bond or may contain heteroatoms and has 1 to 40 carbon atoms in an alkyl group. The aforementioned alkyl group can be straight-chain, branched, or cyclic, and specific examples include alkyldiyl, cyclic saturated alkyl group, and alkylaryl. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, etc.

[0030] Specific examples of alkyl groups with 1 to 40 carbon atoms that may contain heteroatoms, represented by XL, are shown below, but are not limited to these. It should be noted that in the following formulas, * represents the atomic bonds with LA and LB, respectively. [Chemistry 14]

[0031] [Chemistry 15]

[0032] [Chemistry 16]

[0033] [Chemistry 17]

[0034] Among them, XL-0~XL-22 and XL-47~XL-58 are better.

[0035] The onium salt represented by formula (A) is preferably the onium salt represented by formula (A1) below. [Chemistry 18] In the formula, R1~R13, R15, LA, XL, RF, m1~m3 and Z+ are as described above.

[0036] As for the onium salt represented by formula (A1), it is preferable to use the onium salt represented by formula (A2) below. [Chemistry 19] In the formula, R5, R10~R13, R15, LA, XL, RF, m1~m3 and Z+ are as described above.

[0037] In equation (A2), m4 and m5 are each independent integers from 0 to 4. From the perspective of raw material supply, 0 to 2 is preferred.

[0038] In formula (A2), R16 and R17 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms. As specific examples of the aforementioned halogen atoms and hydrocarbon groups, the same groups as those exemplified for the halogen atoms and hydrocarbon groups represented by R1 to R14 can be given.

[0039] When m4 is 2 or more, multiple R16 atoms can bond to each other and form a ring together with the carbon atoms they are bonded to and the carbon atoms between them. When m5 is 2 or more, multiple R17 atoms can also bond to each other and form a ring together with the carbon atoms they are bonded to and the carbon atoms between them. As a specific example of the ring formed in this case, the same example as the ring formed by at least two of R1 to R14 bonding to each other can be given.

[0040] Specific examples of onium salt anions represented by formula (A) are shown below, but are not limited to these. Furthermore, structures formed by combining functional groups from different structures of the following specific examples are also included in this invention. It should be noted that in the following formulas, Me is a methyl group. [Chemistry 20]

[0041] [Chemistry 21]

[0042] [Chemistry 22]

[0043] [Chemistry 23]

[0044] [Chemistry 24]

[0045] [Chemistry 25]

[0046] [Chemistry 26]

[0047] [Chemistry 27]

[0048] [Chemistry 28]

[0049] [Chemistry 29]

[0050] [Chemistry 30]

[0051] [Chemistry 31]

[0052] [Chemistry 32]

[0053] [Chemistry 33]

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[0070] [Transformation 50]

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[0075] [Chemistry 55]

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[0080] [Transformation 60]

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[0201] [Chemistry 181]

[0202] [Chemistry 182]

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[0220] [Chemistry 200]

[0221] In formula (A), Z+ is an onium cation. Preferably, the onium cation is the strontium cation shown in formula (cation-1) or the monium cation shown in formula (cation-2). [Chemical Engineering 201]

[0222] In formulas (cation-1) and (cation-2), Rct1 to Rct5 are each independently a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms containing heteroatoms.

[0223] Rct1~Rct5 represent halogen atoms, such as fluorine, chlorine, bromine, iodine, etc.

[0224] The hydrocarbon groups represented by Rct1 to Rct5 can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, and tributyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, but aryl groups are preferred. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0225] Furthermore, Rct1 and Rct2 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, structures such as those shown in the following formulas can be listed as the aforementioned ring structures. [Chemical Engineering 202] The dashed lines represent the atomic bonds with Rct3.

[0226] Specific examples of strontium cations represented by formula (cation-1) are shown below, but are not limited to these. [Chemical Engineering 203]

[0227] [Chemical 204]

[0228] [Chemical Engineering 205]

[0229] [Chemical Engineering 206]

[0230] [Chemical 207]

[0231] [Chemical Engineering 208]

[0232] [Chemical Engineering 209]

[0233] [Chemical 210]

[0234] [Chemistry 211]

[0235] [Chemistry 212]

[0236] [Chemistry 213]

[0237] [Chemistry 214]

[0238] [Chemical 215]

[0239] [Chemistry 216]

[0240] [Chemistry 217]

[0241] [Chemistry 218]

[0242] [Chemistry 219]

[0243] [Chem.220]

[0244] [Chemistry 221]

[0245] [Chemistry 222]

[0246] [Chemistry 223]

[0247] [Chemistry 224]

[0248] [Chemistry 225]

[0249] [Chemistry 226]

[0250] [Chemistry 227]

[0251] [Chemistry 228]

[0252] [Chemistry 229]

[0253] Specific examples of cation cations represented by formula (cation-2) can be listed below, but are not limited to these. [Chemistry 230]

[0254] [Chemistry 231]

[0255] As a specific example of the above-mentioned onium salt, any combination of the above-mentioned anions and cations can be given.

[0256] The aforementioned onium salts can be synthesized by known methods. As an example, a method for manufacturing an onium salt represented by the following formula (PAG-1-ex) will be described, but the synthesis method is not limited to this. [Chemistry 232] In the formula, R1~R13, RF, R15, LA, XL, m1~m3 and Z+ are as described above. M+ is a relative cation. X- is a relative anion.

[0257] Step 1 involves the reaction of reactants SM-1 (obtained commercially available or by known synthetic methods) and SM-2 to obtain intermediate In-1. When an ester bond is directly formed between the carboxyl group of SM-1 and the hydroxyl group of SM-2, various condensing agents can be used. Examples of condensing agents include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylethylcarbodiimide, 1-[3-(dimethylaminopropyl)propyl]-3-ethylcarbodiimide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. From the viewpoint of ease of removal of the urea compound generated as a byproduct after the reaction, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is preferred. This reaction is carried out by dissolving SM-1 and SM-2 in a halogenated solvent such as chloromethane and adding the condensing agent. Adding 4-dimethylaminopyridine (DMAP) as a catalyst can increase the reaction rate. Monitoring the reaction time using silicone thin-layer chromatography (TLC) to determine when the reaction is complete is preferable for yield purposes, but typically takes about 12–24 hours. After stopping the reaction, remove byproduct urea compounds by filtration or washing with water if necessary, and then perform a standard aqueous work-up to obtain intermediate In-1. If desired, intermediate In-1 can be purified using conventional methods such as chromatography and recrystallization.

[0258] Step 2 involves salt exchange of the obtained intermediate In-1 with an onium salt (represented by Z+X-, starting material SM-3) to obtain the onium salt (PAG-1-ex). It should be noted that chloride ions, bromide ions, iodide ions, or methyl sulfate anions are preferred as X- because the exchange reaction proceeds quantitatively. From a yield perspective, TLC is recommended to confirm the reaction. The onium salt (PAG-1-ex) can be obtained using conventional aqueous work-up. If necessary, purification can be performed using conventional methods such as chromatography or recrystallization.

[0259] In the above scheme, the ion exchange in the second step can be easily carried out by known methods, for example, Japanese Patent Application Publication No. 2007-145797.

[0260] It should be noted that the above manufacturing method is only one example, and the manufacturing method of the above onium salt is not limited to this.

[0261] As structural features of the aforementioned onium salts, examples include the introduction of substituent-containing ring-condensing structures and aromatic sulfonic acid structures into the anion. The ring-condensing structures with substituents have a large exclusion volume, acting as large substituents and effectively suppressing the diffusion of acid-generating compounds. Furthermore, their resistance to alkaline developers reduces the amount of film with patterned unexposed areas. On the other hand, the aromatic sulfonic acid structures have a rigid acid-generating structure, exhibiting an effect of suppressing acid diffusion. It is preferable to have fluorine atoms or electron-withdrawing sulfonate bonds as linking groups in the aromatic rings forming the aromatic sulfonic acid structures, thereby increasing the acidity of the generated acid and effectively deprotecting the acid-unstable groups of the base polymer. Additionally, although fluorine atoms are less potent than iodine atoms, they are highly absorbent of EUV light; therefore, increasing the number of fluorine atoms increases the generation of secondary electrons, promoting cation decomposition and contributing to higher sensitivity. Japanese Patent No. 7109178 discloses an alkane sulfonic acid type photoacid generator with 2 to 4 fluorine atoms. However, since it is an alkane sulfonic acid, it has high acid diffusion and poor solvent resistance, raising concerns about development defects. Through their synergistic effect, the resist composition containing the aforementioned onium salt exhibits high sensitivity and low acid diffusion, thereby enabling the formation of excellent line pattern LWR, hole pattern CDU, and patterns resistant to pattern collapse. Therefore, it is suitable for forming fine patterns.

[0262] In the chemically amplified positive inhibitor composition of the present invention, the content of (A) photoacid generator is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, relative to 80 parts by mass of the base polymer (B) described later. If the content of (A) photoacid generator is within the aforementioned range, the amount of acid required for deprotection of the acid-instable group is generated, resulting in a good pattern shape. Furthermore, good storage stability is also achieved. (A) Photoacid generator can be used alone or in combination of two or more.

[0263] For purposes such as pattern shape correction, the chemically amplified positive inhibitor composition of the present invention may further include an acid generator other than the onium salt represented by formula (A) (hereinafter also referred to as other acid generators). As other acid generators, known acid generators used as inhibitor compositions can be used. Considering sensitivity and acid diffusion inhibition effect, the content of other acid generators is preferably 0 to 40 parts by weight, more preferably 0 to 30 parts by weight, relative to 80 parts by weight of the base polymer described later (B). One other acid generator may be used alone, or two or more may be used in combination.

[0264] [(B) Basic Polymer] The inhibitor composition of the present invention includes a base polymer as component (B), which includes a polymer that decomposes under the action of acid and has increased solubility in alkaline developing solution.

[0265] The aforementioned polymer is preferably a polymer containing repeating units represented by the following formula (B1) (hereinafter also referred to as repeating unit B1). [Chemistry 233]

[0266] In formula (B1), a1 is 0 or 1. a2 is an integer from 0 to 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is an integer from 1 to 3. When a2 is 0, it is preferable that a3 is 0, 1, 2, or 3, and a4 is 1, 2, or 3. When a2 is 1 or 2, it is preferable that a3 is 0, 1, 2, 3, or 4, and a4 is 1, 2, or 3.

[0267] In formula (B1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0268] In formula (B1), R21 is a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The saturated hydrocarbon group and the saturated hydrocarbon oxygen group and saturated hydrocarbon carbonyl oxygen group can be straight-chain, branched, or cyclic, and specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; and groups obtained by combining these groups. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When a3 is 2 or more, each R21 can be the same or different from each other.

[0269] In formula (B1), A1 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and a portion of the -CH2- of this saturated alkyl group may also be replaced by -O-. The aforementioned saturated alkyl group can be any of straight-chain, branched, or cyclic. Specific examples include alkane dimethyl groups with 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkyl groups with 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining them. In addition, when the aforementioned saturated alkyl group contains an ether bond, when a1 in formula (B1) is 1, it can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to the ester oxygen atom. Furthermore, when the aforementioned saturated hydrocarbon group contains an ether bond, if a1 in formula (B1) is 0, the atom bonded to the main chain becomes an ether-type oxygen atom, and a second ether bond can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to this ether-type oxygen atom. It should be noted that if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solutions can be obtained, which is therefore preferable.

[0270] When a1 is 0 and A1 is a single bond, i.e., the aromatic ring is directly bonded to the polymer backbone (i.e., without a linker group (-C(=O)-O-A1-), ideal examples of repeating unit B1 can be units from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. Specifically, substances shown below can be cited, but are not limited to these. It should be noted that RA in the following formulas is the same as described above. [Chemistry 234]

[0271] [Chemistry 235]

[0272] [Chemistry 236]

[0273] When a1 is 1 (i.e., has -C(=O)-O-A1- as a connecting base), ideal examples of repeating units B1 can be given as shown below, but are not limited to these. It should be noted that RA in the following formulas is the same as described above. [Chemistry 237]

[0274] [Chemistry 238]

[0275] [Chemistry 239]

[0276] [Chemistry 240]

[0277] The content of repeating unit B1 is preferably 15-90 mol% in all repeating units constituting the above-described polymer, more preferably 15-80 mol%. However, when the polymer includes at least one of the repeating units represented by formula (B3) and formula (B4) that impart higher etch resistance to the polymer described below, and the aforementioned units have phenolic hydroxyl groups as substituents, it is preferable to add them together and set the content within the aforementioned range. Repeating unit B1 can be used alone or in combination of two or more.

[0278] In order to impart the property that the exposure section is soluble in alkaline developer as a positive resist component, the aforementioned polymer is preferably a repeating unit containing an acidic functional group protected by an acid-instable group, that is, a repeating unit that is protected by an acid-instable group and becomes alkali-soluble by the action of acid (hereinafter also referred to as repeating unit B2).

[0279] As the optimal repeating unit B2, the repeating unit represented by the following formula (B2-1) can be cited (hereinafter also referred to as repeating unit B2-1). [Chemistry 241]

[0280] In formula (B2-1), b1 is 0 or 1. b2 is an integer from 0 to 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is an integer from 1 to 3. b5 is 0 or 1. When b2 is 0, b3 is 0, 1, 2, or 3, and b4 is preferably 1, 2, or 3. When b2 is 1 or 2, b3 is 0, 1, 2, 3, or 4, and b4 is preferably 1, 2, or 3.

[0281] In formula (B2-1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0282] In formula (B2-1), R31 is a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The saturated hydrocarbon group and the saturated hydrocarbon oxygen group and saturated hydrocarbon carbonyl oxygen group can be straight-chain, branched, or cyclic, and specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; and groups obtained by combining these groups. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When b3 is 2 or more, each R31 can be the same or different from each other.

[0283] In formula (B2-1), A2 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and a portion of the -CH2- of this saturated alkyl group may also be replaced by -O-. The aforementioned saturated alkyl group can be any of straight-chain, branched, or cyclic. Specific examples include alkane dimethyl groups with 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkyl groups with 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining them. Furthermore, when the aforementioned saturated alkyl group contains an ether bond, when b1 in formula (B2-1) is 1, it can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to the ester oxygen atom. Furthermore, when b1 is 0, the atom bonded to the main chain becomes an ether oxygen atom, and a second ether bond can be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to this ether oxygen atom. It should be noted that if the number of carbon atoms in the above-mentioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solution can be obtained, which is therefore preferred.

[0284] In formula (B2-1), when b4 is 1, X is an acid-labile group. When b4 is 2 or 3, X is either a hydrogen atom or an acid-labile group independently, but at least one is an acid-labile group. That is, the repeating unit B2-1 is a repeating unit of at least one acid-labile group protected by an acid-labile group of a phenolic hydroxyl group bonded to an aromatic ring, or a repeating unit of a carboxyl group bonded to an aromatic ring protected by an acid-labile group. As for the aforementioned acid-labile group, it can be used without particular limitation as long as it is an acid-labile group that has been desorbed by acid and provides an acidic group in a variety of known chemical amplification positive inhibitor compositions.

[0285] Examples of acid-instable groups include, for instance, tertiary saturated hydrocarbon groups. For obtaining the monomer for polymerization by distillation, the aforementioned tertiary saturated hydrocarbon groups preferably have 4 to 18 carbon atoms.

[0286] As for the saturated hydrocarbon groups bonded to the tertiary carbon atoms of the aforementioned tertiary saturated hydrocarbon groups, saturated hydrocarbon groups with 1 to 15 carbon atoms are preferred. These saturated hydrocarbon groups with 1 to 15 carbon atoms can be straight-chain, branched, or cyclic, and may contain oxygen-containing functional groups such as ether bonds or carbonyl groups between their carbon-carbon bonds. Furthermore, the saturated hydrocarbon groups bonded to the tertiary carbon atoms can bond to each other to form a ring together with the tertiary carbon atoms to which they are bonded.

[0287] Examples of alkyl substituents include methyl, ethyl, propyl, adamantyl, norbornel, tetrahydrofuran-2-yl, 7-oxanorborne-2-yl, cyclopentyl, 2-tetrahydrofuranyl, tricyclo[5.2.1.02,6]decyl, 8-ethyl-8-tricyclo[5.2.1.02,6]decyl, 3-methyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, tetracyclo[4.4.0.1]2,5.17,10]dodecyl, and 3-sideoxy-1-cyclohexyl.

[0288] Examples of the aforementioned third-order saturated hydrocarbon groups include tert-butyl, tert-pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1-adamantyl-1-methylethyl, 1-methyl-1-(2-norborneol)ethyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 1-methyl-1-(7-oxanorborneol-2-yl)ethyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-propylcyclopentyl, 1-cyclopentylcyclopentyl, 1-cyclohexylcyclopentyl, 1-(2-tetrahydrofuranyl)cyclopentyl, 1-(7-oxanorborneol-2-yl)cyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 1-cyclopentylcyclohexyl, 1-cyclohexylcyclohexyl, and 1-cyclohexyl ... Hexyl, 2-methyl-2-norborneol, 2-ethyl-2-norborneol, 8-methyl-8-tricyclo[5.2.1.02,6]decyl, 8-ethyl-8-tricyclo[5.2.1.02,6]decyl, 3-methyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, 3-ethyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 1-methyl-3-sideoxy-1-cyclohexyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 5-hydroxy-2-methyl-2-adamantyl, 5-hydroxy-2-ethyl-2-adamantyl, but not limited to these.

[0289] Furthermore, the group represented by formula (B2-1-1) can be listed as an example of the aforementioned acid-indestabilizing group. The group represented by formula (B2-1-1) is frequently used as an acid-indestabilizing group and is a useful choice as an acid-indestabilizing group that stably provides a relatively rectangular pattern at the interface between the pattern and the substrate. When X is the group represented by formula (B2-1-1), an acetal structure is formed. [Chemistry 242] In the formula, the dashed lines represent atomic bonds.

[0290] In formula (B2-1-1), RL1 is a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. The saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0291] RL1 can be appropriately selected based on the design of the sensitivity of the decomposable group to acids. For example, if the design aims to decompose with strong acids while ensuring relatively high stability, a group with a hydrogen atom or a carbon atom bonded to the acetal carbon as a tertiary carbon atom is preferred. Examples of RL1 with a tertiary carbon atom bonded to the acetal carbon include tributyl, tripentyl, and 1-adamantyl, but are not limited to these. If the design aims for high reactivity and high sensitivity to pH changes, a straight-chain alkyl group is preferred. Although it also depends on the combination with the acid generator and quencher incorporated in the inhibitor composition, for RL2, if the solubility change caused by decomposition is designed to be large, and the alkyl group with a larger terminal size is chosen, then for RL1, a carbon atom bonded to the acetal carbon is preferably a secondary carbon atom. Examples of RL1 with a secondary carbon atom bonded to the acetal carbon include isopropyl, tributyl, cyclopentyl, and cyclohexyl, but are not limited to these.

[0292] In formula (B2-1-1), RL2 is a hydrocarbon group with 1 to 30 carbon atoms. This hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. A portion of the -CH2- group is replaced by heteroatoms such as oxygen or sulfur atoms, resulting in the presence of ether bonds, thioether bonds, etc. Specific examples of this hydrocarbon group include saturated hydrocarbon groups with 1 to 30 carbon atoms and aryl groups with 6 to 30 carbon atoms. In particular, in the formation of fine patterns, RL2 is preferably a hydrocarbon group with 1 to 6 carbon atoms to obtain higher resolution. When RL2 is a hydrocarbon group with 1 to 6 carbon atoms, the alcohol generated after the deprotection reaction using acid is water-soluble. Therefore, it dissolves in the developer during positive pattern formation using an alkaline developer, thus suppressing residual defects in the exposed area.

[0293] Ideal examples of the base represented by formula (B2-1-1) can be listed below, but are not limited to these. It should be noted that in the following formulas, RL1 is as described above, and the dashed lines represent atomic bonds. [Chemistry 243]

[0294] [Chemistry 244]

[0295] As an unstable group in other acids, a group in which the hydrogen atom of the phenolic hydroxyl group is replaced by -CH2COO- (a tertiary saturated hydrocarbon group) can be used. In this case, the same tertiary saturated hydrocarbon group used in the protection of the aforementioned phenolic hydroxyl group can be used as the tertiary saturated hydrocarbon group.

[0296] Furthermore, as a repeating unit B2, another example is the repeating unit represented by the following formula (B2-2) (hereinafter also referred to as repeating unit B2-2). Since the dissolution rate of the exposure section is increased, repeating unit B2-2 is a useful choice as a unit containing an acid-containing unstable group that imparts good performance to linewidth variations during development loading. [Chemistry 245]

[0297] In equation (B2-2), c1 is an integer from 0 to 2. c2 is an integer from 0 to 2. c3 is an integer from 0 to 5. c4 is an integer from 0 to 2.

[0298] In formula (B2-2), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0299] In formula (B2-2), R32 and R33 are each independently hydrocarbon groups with 1 to 10 carbon atoms, which may also contain heteroatoms. R32 and R33 may also bond to each other and form a ring together with the carbon atoms they are bonded to.

[0300] In formula (B2-2), R34 are each independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms.

[0301] In formula (B2-2), R35 is an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0302] In formula (B2-2), A3 represents a single bond, an phenyl group, a naphthyl group, or *-C(=O)-O-A31. -A31 is an aliphatic alkyl group with 1 to 20 carbon atoms, which may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring, or an phenyl or naphthyl group. * indicates an atomic bond with a carbon atom in the main chain.

[0303] As an ideal example of repeating unit B2-2, the following repeating units can be cited, but are not limited to these. It should be noted that in the following formulas, RA is the same as described above. [Chemistry 246]

[0304] [Chemistry 247]

[0305] The content of repeating unit B2 in all repeating units constituting the above polymer is preferably 5-95 mol%, more preferably 20-80 mol%. Repeating unit B2 can be used alone or in combination of two or more types.

[0306] The aforementioned polymer may contain at least one of the repeating units represented by the following formula (B3) (hereinafter also referred to as repeating unit B3), the repeating units represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), and the repeating units represented by the following formula (B5) (hereinafter also referred to as repeating unit B5). [Chemistry 248]

[0307] In equations (B3) and (B4), d is an integer from 0 to 6, and e is an integer from 0 to 4.

[0308] In formulas (B3) and (B4), R41 and R42 are each independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The saturated hydrocarbon group, saturated hydrocarbon oxygen group, and saturated hydrocarbon carbonyl oxygen group can be straight-chain, branched, or cyclic. When d is 2 or more, each R41 can be the same or different from each other. When e is 2 or more, each R42 can be the same or different from each other.

[0309] In formula (B5), f1 is 0 or 1. f2 is an integer from 0 to 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. f3 is an integer from 0 to 5. When f2 is 0, f3 is preferably 0, 1, 2, or 3; when f2 is 1 or 2, f3 is preferably 0, 1, 2, 3, or 4.

[0310] In formula (B5), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0311] In formula (B5), R43 can be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, a saturated hydrocarbon thioalkyl group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a nitrile group. When f2 is 1 or 2, it can be a hydroxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxygen group, saturated hydrocarbon carbonyl oxygen group, saturated hydrocarbon oxygen group, and saturated hydrocarbon thioalkyl group can be straight-chain, branched, or cyclic. When f3 is 2 or more, each R43 can be the same or different from the others.

[0312] In formula (B5), A4 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group may also be replaced by -O-. The above-mentioned saturated hydrocarbon group can be any of the straight-chain, branched, or cyclic forms. As a specific example, the same substance as the substance exemplified in the description of A1 in formula (B1) can be given.

[0313] When at least one of repeating units B3 to B5 is used as a constituent unit of the aforementioned polymer, in addition to the etch resistance of the aromatic ring, the effect of improving etch resistance or EB irradiation resistance during pattern inspection can be obtained by adding a ring structure to the main chain.

[0314] To improve etch resistance, the content of repeating units B3 to B5 is preferably 5 mol% or more among all repeating units constituting the aforementioned polymer. Furthermore, the content of repeating units B3 to B5 is preferably 25 mol% or less, and more preferably 20 mol% or less, among all repeating units constituting the aforementioned polymer. If the amount introduced is 25 mol% or less when there are no functional groups or when the functional groups are other than hydroxyl groups, there is no risk of developing defects, which is therefore preferable. Repeating units B3 to B5 can be used alone or in combination of two or more.

[0315] When the aforementioned polymer comprises repeating unit B1, repeating unit B2, and at least one of repeating units selected from B3 to B5, it is ideal to achieve a good balance between high etch resistance and resolution. In this case, it is preferable that these repeating units comprise 60 mol% or more of all repeating units in the aforementioned polymer, more preferably 70 mol% or more, even more preferably 80 mol% or more, and more preferably 90 mol% or more.

[0316] The aforementioned polymer may contain at least one of the repeating units represented by formula (B6) (hereinafter also referred to as repeating unit B6), the repeating units represented by formula (B7) (hereinafter also referred to as repeating unit B7), the repeating units represented by formula (B8) (hereinafter also referred to as repeating unit B8), and the repeating units represented by formula (B9) (hereinafter also referred to as repeating unit B9). [Chemistry 249]

[0317] In formulas (B6) to (B9), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X1 is a single bond or an phenyl group. X2 is *1-C(=O)-O-X21-, *1-C(=O)-NH-X21-, or *1-O-X21-. X21 is an aliphatic alkyl group, phenyl group, or a divalent group obtained by combining them, having 1 to 6 carbon atoms; it may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. *1 represents the atomic bond with X1. X3 is independently a single bond, an phenyl group, a naphthyl group, or *2-C(=O)-O-X31-. X31 is an aliphatic alkyl group, phenyl group, or naphthyl group, having 1 to 10 carbon atoms; this aliphatic alkyl group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. *2 represents the atomic bond with a carbon atom of the main chain. X4 independently represents a single bond, *3-X41-C(=O)-O-, *3-C(=O)-NH-X41-, or *3-O-X41-X. X41 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms. *3 indicates an atomic bond with X3. X5 independently represents a single bond, *4-X51-C(=O)-O-, *4-C(=O)-NH-X51-, or *4-O-X51. -X51 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms. *4 indicates an atomic bond with X4. X6 represents a single bond, methylene, ethyl alkyl, phenyl alkyl, fluorinated phenyl alkyl, phenyl alkyl substituted with trifluoromethyl, *2-C(=O)-O-X61-, *2-C(=O)-N(H)-X61-, or *2-O-X61-. X61 is an aliphatic phenyl group, phenyl group, fluorinated phenyl group, or phenyl group substituted with trifluoromethyl group, which has 1 to 6 carbon atoms. It may also contain carbonyl group, ester bond, ether bond, or hydroxyl group. *2 indicates an atomic bond with a carbon atom in the main chain.

[0318] The aliphatic alkyl groups represented by X21, X31, and X61 can be straight-chain, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, and butane-1,2-diyl. Alkane dimethyl groups, including butane-1,3-dimethyl, butane-2,3-dimethyl, butane-1,4-dimethyl, 1,1-dimethylethane-1,2-dimethyl, pentane-1,5-dimethyl, 2-methylene-n-butane-1,2-dimethyl, and hexane-1,6-dimethyl; cycloalkane dimethyl groups such as cyclopropane dimethyl, cyclobutane dimethyl, cyclopentane dimethyl, and cyclohexane dimethyl; and dimethyl groups obtained by combining them.

[0319] The alkyl groups represented by X41 and X51 can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be given as shown below, but are not limited to these. [Chemistry 250] In the formula, the dashed lines represent atomic bonds.

[0320] In formula (B6), R51 and R52 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, and tributyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, with aryl groups being preferred. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0321] Furthermore, R51 and R52 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the ring described above is the same as the ring exemplified in the description of formula (cation-1) where Rct1 and Rct2 are bonded together and can form a ring together with the sulfur atoms they are bonded to.

[0322] Specific examples of cations that are repeating unit B6 include the cations shown below, but are not limited to these. It should be noted that RA in the following formulas is the same as described above. [Chemistry 251]

[0323] [Chemistry 252]

[0324] [Chemistry 253]

[0325] [Chemistry 254]

[0326] [Chemistry 255]

[0327] [Chemistry 256]

[0328] [Chemistry 257]

[0329] In formula (B6), M- represents a non-nucleophilic relative ion. Preferably, these non-nucleophilic relative ions are halide ions, sulfonic acid anions, amide anions, and methyl acid anions. Specific examples of the halide ions include chloride ions and bromide ions. Specific examples of the sulfonic acid anions (sulfonate ions) include fluoroalkyl sulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoromethanesulfonate ion, and nonafluorobutanesulfonate ion; aryl sulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, and 1,2,3,4,5-pentafluorobenzenesulfonate ion; and alkyl sulfonate ions such as methanesulfonate ion and butanesulfonate ion. Specific examples of the aforementioned amide acid anions (amide ions) include bis(trifluoromethanesulfonyl)amide ions, bis(perfluoroethylsulfonyl)amide ions, and bis(perfluorobutylsulfonyl)amide ions. Specific examples of the aforementioned methylated acid anions (methylated ions) include tris(trifluoromethanesulfonyl)methylated ions and tris(perfluoroethylsulfonyl)methylated ions.

[0330] As other examples of the aforementioned non-nucleophilic relative ions, anions represented by any of the following formulas (B6-1) to (B6-4) can be listed. [Chemistry 258]

[0331] In formula (B6-1), Rfa is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. As a specific example, the same group as the group exemplified by the hydrocarbon group represented by Rfa1 in formula (B6-1-1) described later can be given.

[0332] The anion represented by formula (B6-1) is preferably the anion represented by the following formula (B6-1-1). [Chemistry 259]

[0333] In formula (B6-1-1), Q11 and Q12 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, but to improve solvent resistance, at least one is preferably trifluoromethyl. m is an integer from 0 to 4, and is particularly preferably 1. Rfa1 is a hydrocarbon group having 1 to 35 carbon atoms, which may also contain heteroatoms. Heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., and more preferably oxygen atoms. As for the above-mentioned hydrocarbon group, from the viewpoint of obtaining high resolution in the formation of fine patterns, hydrocarbon groups having 6 to 30 carbon atoms are particularly preferred.

[0334] In formula (B6-1-1), the hydrocarbon group represented by Rfa1, which has 1 to 35 carbon atoms, can be saturated or unsaturated, and can be straight-chain, branched or cyclic. Specific examples include alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-enyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0335] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, nitrile, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-sideoxypropyl, 4-sideoxy-1-adamantyl, and 3-sideoxycyclohexyl.

[0336] In formula (B6-1-1), La1 is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond. From a synthetic point of view, it is preferred to be an ether bond or an ester bond, and even more preferably an ester bond.

[0337] Anions represented by formula (B6-1) can be listed below, but are not limited to these. It should be noted that in the following formulas, Q11 is the same as described above, and Ac is acetyl. [Chemistry 260]

[0338] [Chemistry 261]

[0339] [Chemistry 262]

[0340] [Chemistry 263]

[0341] [Chemistry 264]

[0342] [Chemistry 265]

[0343] [Chemistry 266]

[0344] [Chemistry 267]

[0345] [Chemistry 268]

[0346] [Chemistry 269]

[0347] In formula (B6-2), Rfb1 and Rfb2 are each independently a fluorine atom or a hydrocarbon having 1 to 40 carbon atoms, and may also contain heteroatoms. The aforementioned hydrocarbons may be saturated or unsaturated, and may be linear, branched, or cyclic. As a specific example, a group similar to the one represented by Rfa1 in formula (B6-1-1) can be given. Rfb1 and Rfb2 are preferably fluorine atoms or linear fluorinated alkyl groups having 1 to 4 carbon atoms. In addition, Rfb1 and Rfb2 can bond to each other and form a ring together with the group they bond to (-CF2-SO2-N--SO2-CF2-). In this case, the group obtained by the mutual bonding of Rfb1 and Rfb2 is preferably fluorinated ethyl or fluorinated propyl.

[0348] In formula (B6-3), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. As a specific example, the same group as the one exemplified by the hydrocarbon group represented by Rfa1 in formula (B6-1-1) can be given. Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or straight-chain fluorinated alkyl groups with 1 to 4 carbon atoms. Alternatively, Rfc1 and Rfc2 can bond to each other and form a ring together with the group they are bonded to (-CF2-SO2-C--SO2-CF2-). In this case, the group obtained by the mutual bonding of Rfc1 and Rfc2 is preferably fluorinated ethyl or fluorinated propyl.

[0349] In formula (B6-4), Rfd is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. As a specific example, the same group as the hydrocarbon group represented by Rfa1 in formula (B6-1-1) can be given.

[0350] Examples of anions represented by formula (B6-4) are shown below, but are not limited to these. [Chemistry 270]

[0351] [Chemistry 271]

[0352] Examples of the aforementioned non-nucleophilic relative ions also include anions having aromatic rings substituted with iodine or bromine atoms. Specific examples of such anions include the anion represented by the following formula (B6-5). [Chemistry 272]

[0353] In equation (B6-5), p is an integer satisfying 1 ≤ p ≤ 3. q and r are integers satisfying 1 ≤ q ≤ 5, 0 ≤ r ≤ 3, and 1 ≤ q + r ≤ 5. q is preferably 1, 2, or 3, more preferably 2 or 3. r is preferably 0, 1, or 2.

[0354] In formula (B6-5), XBI is an iodine atom or a bromine atom, and when p and / or q are 2 or more, they can be the same or different.

[0355] In formula (B6-5), L1 is a single bond, ether bond, or ester bond, or a saturated alkyl group with 1 to 6 carbon atoms that may contain ether or ester bonds. The aforementioned saturated alkyl group can be any of the following: straight-chain, branched, or cyclic.

[0356] In formula (B6-5), L2 is a single bond or a divalent linker with 1 to 20 carbon atoms when p is 1, and a (p+1) valent linker with 1 to 20 carbon atoms when p is 2 or 3. This linker may contain oxygen, sulfur or nitrogen atoms.

[0357] In formula (B6-5), Rfe represents a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a 1-20 carbon-1 hydrocarbon group, a 1-20 carbon-1 hydrocarbon oxygen group, a 2-20 carbon-2 hydrocarbon carbonyl group, a 2-20 carbon-2 hydrocarbon oxygen carbonyl group, a 2-20 carbon-2 hydrocarbon carbonyl oxygen group, or a 1-20 carbon-1 hydrocarbon sulfonyl oxygen group, or -N(RfeA)(RfeB), -N(RfeC)-C(=O)-RfeD, or -N(RfeC)-C(=O)-O-RfeD. RfeA and RfeB are each independently a hydrogen atom or a 1-6 carbon-1 saturated hydrocarbon group. RfeC is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated alkyloxy group having 1 to 6 carbon atoms, a saturated alkyl carbonyl group having 2 to 6 carbon atoms, or a saturated alkyl carbonyloxy group having 2 to 6 carbon atoms. RfeD is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated alkyloxy group having 1 to 6 carbon atoms, a saturated alkyl carboxyl group having 2 to 6 carbon atoms, or a saturated alkyl carbonyloxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, alkyloxy group, alkyl carbonyl group, alkyl carbonyloxy group, and alkyl sulfonyloxy group can be straight-chain, branched, or cyclic. When p and / or r are 2 or more, each Rfe can be the same or different from the others.

[0358] Among them, hydroxyl groups, -N(RfeC)-C(=O)-RfeD, -N(RfeC)-C(=O)-O-RfeD, fluorine atoms, chlorine atoms, bromine atoms, methyl groups, and methoxy groups are preferred as Rfe.

[0359] In formula (B6-5), Rf11 to Rf14 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Additionally, Rf11 and Rf12 can be bonded to form a carbonyl group. Preferably, both Rf13 and Rf14 are fluorine atoms.

[0360] Examples of anions represented by formula (B6-5) are shown below, but are not limited to these. It should be noted that XBI in the following formulas are the same as previously stated. [Chemistry 273]

[0361] [Chemistry 274]

[0362] [Chemistry 275]

[0363] [Chemistry 276]

[0364] [Chemistry 277]

[0365] [Chemistry 278]

[0366] [Chemistry 279]

[0367] [Chemistry 280]

[0368] [Chemistry 281]

[0369] [Chemistry 282]

[0370] [Chemistry 283]

[0371] [Chemistry 284]

[0372] [Chemistry 285]

[0373] [Chemistry 286]

[0374] [Chemistry 287]

[0375] [Chemistry 288]

[0376] [Chemistry 289]

[0377] [Chemistry 290]

[0378] [Chemistry 291]

[0379] [Chemistry 292]

[0380] [Chemistry 293]

[0381] [Chemistry 294]

[0382] [Chemistry 295]

[0383] As the aforementioned non-nucleophilic relative ions, the fluorobenzenesulfonic acid anion bonded to an aromatic group containing an iodine atom as disclosed in Japanese Patent No. 6648726, the anion having a mechanism for decomposition by acid as disclosed in Japanese Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692, the anion having a cyclic ether group as disclosed in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935, and the anion disclosed in Japanese Patent Application Publication No. 2018-92159 may also be used.

[0384] As the aforementioned non-nucleophilic relative ions, the following can also be used: the anion of a bulky benzenesulfonic acid derivative without fluorine atoms as described in Japanese Patent Application Publication No. 2006-276759, Japanese Patent Application Publication No. 2015-117200, Japanese Patent Application Publication No. 2016-65016 and Japanese Patent Application Publication No. 2019-202974; the benzenesulfonic acid anion without fluorine atoms bonded to aromatic groups containing iodine atoms as described in Japanese Patent No. 6645464; and the alkylsulfonic acid anion.

[0385] As the aforementioned non-nucleophilic relative ions, the anions of disulfonic acid described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonamide and sulfenamide that are different from sulfonic acid on one side as described in International Publication No. 2020 / 158366, and the anions of sulfonamide and sulfenimine that are different from sulfonic acid on the other side as described in Japanese Patent Application Publication No. 2015-24989, can also be used.

[0386] In formulas (B7) and (B8), L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, carbonate bond, or carbamate bond. From a synthetic point of view, ether bonds, ester bonds, and carbonyl groups are preferred, with ester bonds and carbonyl groups being even more preferred.

[0387] In formula (B7), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Preferably, both Rf1 and Rf2 are fluorine atoms to improve the acid strength of the generated acid. Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Of these, to improve solvent solubility, at least one of Rf3 and Rf4 is preferably trifluoromethyl.

[0388] In formula (B8), Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. However, not all Rf5 and Rf6 are simultaneously hydrogen atoms. Among these, to improve solvent solubility, at least one of Rf5 and Rf6 is preferably trifluoromethyl.

[0389] In equations (B7) and (B8), g1 and g2 are integers from 0 to 3, preferably 1.

[0390] Specific examples of anions for repeating unit B7 include the anions shown below, but are not limited to these. It should be noted that RA in the following formulas is the same as described above. [Chemistry 296]

[0391] [Chemistry 297]

[0392] [Chemistry 298]

[0393] [Chemistry 299]

[0394] [Chemical 300]

[0395] [Chemical Engineering 301]

[0396] [Chemical 302]

[0397] Specific examples of anions of repeating unit B8 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is as described above. [Chemical 303]

[0398] [Chemical 304]

[0399] [Chemical 305]

[0400] [Chemical 306]

[0401] [Chemical 307]

[0402] [Chemical 308]

[0403] [Chemical 309]

[0404] Specific examples of anions for repeating unit B9 include the anions shown below, but are not limited to these. It should be noted that RA in the following formulas is the same as described above. [Chemical 310]

[0405] In formulas (B6) to (B9), A+ is an onium cation. Examples of onium cations include strontium cations, ferrophosphate cations, and ammonium cations, but strontium cations or ferrophosphate cations are preferred. Specific examples of strontium cations are the same as those exemplified as examples of strontium cations represented by formula (cation-1). Specific examples of ferrophosphate cations are the same as those exemplified as examples of ferrophosphate cations represented by formula (cation-2).

[0406] Repeating units B6-B9 are units that generate acid through irradiation with high-energy rays. Furthermore, it is believed that by including these units in the polymer, acid diffusion is moderately suppressed, resulting in a pattern with reduced LER (Left-to-Rate) density. Additionally, it is believed that by including these units in the polymer, the phenomenon of acid evaporation from the exposed areas and re-adhesion to the unexposed areas during vacuum baking is suppressed, which is effective in reducing LER and minimizing shape degradation caused by undesirable film reduction in the unexposed areas.

[0407] Among repeating units B6 to B9, considering the factors of suppressing acid diffusion and the optimal acid strength in terms of designing acid-instable groups in polymers, repeating units B7 to B9 are better, and repeating units B7 and B8 are even better, as they are suitable for processing blank photomasks.

[0408] The repeating units B6 to B9 are preferably introduced in the range of 0.1 mol% to 30 mol% in all repeating units of the aforementioned polymer, and more preferably in the range of 0.5 mol% to 20 mol%. Repeating units B6 to B9 can be used alone or in combination of two or more.

[0409] In all repeating units of the above polymer, the content of repeating units having an aromatic ring skeleton is preferably 65 mol% or more, more preferably 75 mol% or more, and even more preferably 85 mol% or more. In the absence of repeating units B6 to B9, it is preferable that all units have an aromatic ring skeleton.

[0410] The aforementioned polymers may also contain commonly used (meth)acrylate units protected by acid-labile groups, (meth)acrylate units with close-knit groups such as lactone structures and hydroxyl groups other than phenolic hydroxyl groups. These repeating units allow for fine-tuning of the properties of the resist film, but they may also be omitted.

[0411] Examples of the aforementioned (meth)acrylate units with adhesion groups include repeating units represented by formula (B10) (hereinafter also referred to as repeating unit B10), repeating units represented by formula (B11) (hereinafter also referred to as repeating unit B11), and repeating units represented by formula (B12) (hereinafter also referred to as repeating unit B12). These units do not exhibit acidity and can be used auxiliaryly as units that impart adhesion to the substrate or adjust solubility. [Chemistry 311]

[0412] In formulas (B10) to (B12), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R61 is -O- or a methylene group. R62 is a hydrogen atom or a hydroxyl group. R63 is a saturated hydrocarbon group with 1 to 4 carbon atoms. h is an integer from 0 to 3.

[0413] When repeating units B10 to B12 are included, their content in all repeating units of the above polymer is preferably 0 to 20 mol%, more preferably 0 to 10 mol%. Repeating units B10 to B12 can be used alone or in combination of two or more.

[0414] The aforementioned polymer can be synthesized by copolymerizing monomers, which are protected by protecting groups as needed, using known methods, followed by deprotection reactions as required. The copolymerization reaction is not particularly limited, but free radical polymerization and anionic polymerization are preferred. For information on these methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0415] The weight-average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 50,000, and more preferably 2,000 to 20,000. If Mw is 1,000 or higher, the phenomenon of rounding of the pattern head leading to reduced resolution and LER degradation, as is known in the past, will not occur. On the other hand, if Mw is 50,000 or lower, LER will not degrade, especially when forming patterns with a pattern width of 100 nm or less. It should be noted that in this invention, Mw is a polystyrene equivalent value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylformamide (DMF) as solvents.

[0416] The polymer described above preferably has a narrow dispersion with a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, more preferably 1.0 to 1.9, and even more preferably 1.0 to 1.8. With such a narrow dispersion, no foreign matter or pattern shape deterioration will occur on the pattern after development.

[0417] Furthermore, regarding the aforementioned basic polymer design, the dissolution rate to alkaline developer is preferably 10 nm / min or less, more preferably 7 nm / min or less, and even more preferably 5 nm / min or less. In advanced generations, when the coating film on the substrate is a thin area (100 nm or less), the reduction in pattern film has a greater impact on alkaline development. When the alkaline dissolution rate of the polymer exceeds 10 nm / min, the pattern breaks down, making it impossible to form fine patterns. In particular, in the fabrication of photomasks requiring defect-free results, there is a tendency for strong development processing, which is therefore significant. It should be noted that, in this invention, the dissolution rate of the base polymer in the alkaline developer is calculated as follows: a polymer solution (polymer concentration: 16.7% by mass, solvent: propylene glycol monomethyl ether acetate (PGMEA)) is spin-coated onto an 8-inch silicon wafer, baked at 100°C for 90 seconds to form a film with a thickness of 1000 nm, and then developed in a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution at 23°C for 100 seconds. The amount of film reduction at this time is calculated.

[0418] (B) The base polymer of the component may include other polymers besides those described above. Other polymers may be existing and known polymers used as base polymers in inhibitor compositions. The content of other polymers is not particularly limited as long as it does not impair the effects of the invention.

[0419] [(C) Organic solvent] The inhibitor composition of the present invention may include an organic solvent as component (C). As for the solvent, there is no particular limitation as long as it is capable of dissolving each component. Examples of such organic solvents include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; and propylene glycol monomethyl ether (PGME). Ethers such as ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate (EL), ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tributyl acetate, tributyl propionate, and propylene glycol monobutyl ether acetate; lactones such as γ-butyrolactone; and mixed solvents thereof. When using the unstable acid group of an acetal system, high-boiling-point alcohol solvents can be added to accelerate the deprotection reaction of the acetal, specifically diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, and 1,3-butanediol.

[0420] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and their mixed solvents are preferred.

[0421] When the chemical amplification positive inhibitor composition of the present invention contains (C) organic solvent, its content relative to 80 parts by mass of (B) base polymer is preferably 200 to 10,000 parts by mass, and more preferably 400 to 5,000 parts by mass. (C) Organic solvent can be used alone or in combination with two or more.

[0422] [(D) Polymers containing fluorine atoms] The chemically amplified positive resist composition of the present invention may contain a fluorine-containing polymer as component (D) for the purposes of high contrast, suppression of chemical flash phenomenon of acid under high-energy ray irradiation, shielding of mixing of acid from antistatic film during the process of coating antistatic film material onto resist film, and suppression of unexpected and unnecessary pattern degradation. The fluorine-containing polymer contains at least one of the repeating units represented by formula (D1) (hereinafter also referred to as repeating unit D1), repeating units represented by formula (D2) (hereinafter also referred to as repeating unit D2), repeating units represented by formula (D3) (hereinafter also referred to as repeating unit D3), and repeating units represented by formula (D4) (hereinafter also referred to as repeating unit D4). It may also further contain at least one of the repeating units represented by formula (D5) (hereinafter also referred to as repeating unit D5) and repeating units represented by formula (D6) (hereinafter also referred to as repeating unit D6). The aforementioned fluorine-containing polymers also function as surfactants, thus preventing the re-adhesion of insoluble substances that may be generated during the development process to the substrate, and therefore also playing a role in combating development defects. [Chemistry 312]

[0423] In equations (D1) to (D6), j1 is an integer from 1 to 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is an integer from 1 to 3. RB are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. RC are each independently a hydrogen atom or a methyl group. R101, R102, R104, and R105 are each independently a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. R103, R106, R107, and R108 are each independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group with 1 to 15 carbon atoms, or an acid-unstable group. When R103, R106, R107, and R108 are hydrocarbon groups or fluorinated hydrocarbon groups, an ether bond or a carbonyl group can be inserted between the carbon-carbon bonds. R109 is a 1-5 carbon-chain hydrocarbon group, either a hydrogen atom or a straight-chain or branched group containing a heteroatom that may be inserted between carbon-carbon bonds. R110 is a 1-5 carbon-chain hydrocarbon group, either a straight-chain or branched group containing a heteroatom that may be inserted between carbon-carbon bonds. R111 is a 1-20 carbon-chain saturated hydrocarbon group, where at least one hydrogen atom is replaced by a fluorine atom; part of the -CH2- of the aforementioned saturated hydrocarbon group may also be replaced by an ester or ether bond. Z1 is a (k+1) valence hydrocarbon group with 1-20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1-20 carbon atoms. Z2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Z3 represents a single bond, -O-, *-C(=O)-O-Z31-Z32-, or *-C(=O)-NH-Z31-Z32-. Z31 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. Z32 is a single bond, ester bond, ether bond, or sulfonamide bond. * indicates an atomic bond with a carbon atom in the main chain.

[0424] In formulas (D1) and (D2), R101, R102, R104, and R105 represent saturated hydrocarbon groups with 1 to 10 carbon atoms, which can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, saturated hydrocarbon groups with 1 to 6 carbon atoms are preferred.

[0425] In formulas (D1) to (D4), the hydrocarbon groups represented by R103, R106, R107, and R108, having 1 to 15 carbon atoms, can be straight-chain, branched, or cyclic. Specific examples include alkyl groups having 1 to 15 carbon atoms, alkenyl groups having 2 to 15 carbon atoms, and alkynyl groups having 2 to 15 carbon atoms, with alkyl groups having 1 to 15 carbon atoms being more preferred. In addition to the aforementioned groups, other alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecanyl. Furthermore, as fluorinated hydrocarbon groups, groups formed by replacing some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon groups with fluorine atoms can be cited.

[0426] In formula (D4), Z1 represents a (k+1) valence hydrocarbon group having 1 to 20 carbon atoms, which can be exemplified by a group that further removes k hydrogen atoms from an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Furthermore, as a (k+1) valence fluorinated hydrocarbon group representing Z1 with 1 to 20 carbon atoms, it can be exemplified by a group in which at least one hydrogen atom of the aforementioned (k+1) valence hydrocarbon group is replaced by a fluorine atom.

[0427] Specific examples of repeating units D1 to D4 can be given below, but are not limited to these. It should be noted that RB in the following formulas is the same as described above. [Chemistry 313]

[0428] [Chemical 314]

[0429] [Chemical 315]

[0430] In formula (D5), the hydrocarbon groups with 1 to 5 carbon atoms represented by R109 and R110 can include alkyl, alkenyl, and alkynyl groups, with alkyl being preferred. Examples of the aforementioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, and n-pentyl. Furthermore, heteroatoms containing oxygen, sulfur, or nitrogen atoms can be inserted between the carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0431] In formula (D5), -OR109 is preferably a hydrophilic group. In this case, R109 is preferably a hydrogen atom, an alkyl group with 1 to 5 carbon atoms with oxygen atoms inserted between carbon-carbon bonds, etc.

[0432] In formula (D5), Z2 is preferably *-C(=O)-O- or *-C(=O)-NH-. Furthermore, RC is preferably methyl. The presence of a carbonyl group in Z2 enhances the acid capture ability from the antistatic film. Additionally, when RC is methyl, it becomes a rigid polymer with a higher glass transition temperature (Tg), thus suppressing acid diffusion. Consequently, the resistive film exhibits good stability over time, without deterioration in resolution or pattern shape.

[0433] As a repeating unit D5, examples of repeating units can be shown below, but are not limited to these. It should be noted that in the following formulas, RC is the same as described above. [Chemistry 316]

[0434] [Chemistry 317]

[0435] In formula (D6), the saturated extended hydrocarbon group with 1 to 10 carbon atoms represented by Z3 can be any of the following: straight-chain, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, and 1,1-dimethylethane-1,2-diyl.

[0436] In formula (D6), R111 represents a saturated hydrocarbon group with 1 to 20 carbon atoms whose at least one hydrogen atom is replaced by a fluorine atom. It can be any of the following: straight chain, branched chain, or cyclic. As a specific example, an alkyl group with 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group with 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom can be given.

[0437] As a repeating unit D6, examples of repeating units can be shown below, but it is not limited to these. It should be noted that in the following formulas, RC is the same as described above. [Chemistry 318]

[0438] [Chemistry 319]

[0439] [Chem.320]

[0440] [Chemistry 321]

[0441] The content of repeating units D1 to D4 in the above-mentioned polymer containing fluorine atoms is preferably 15 to 95 mol%, more preferably 20 to 85 mol%. The content of repeating units D5 and / or D6 in the above-mentioned polymer containing fluorine atoms is preferably 5 to 85 mol%, more preferably 15 to 80 mol%. Repeating units D1 to D6 can be used alone or in combination of two or more.

[0442] (D) The polymer containing fluorine atoms may include other repeating units besides the aforementioned repeating units. Examples of such repeating units include those described in paragraphs

[0046] to

[0078] of Japanese Patent Application Publication No. 2014-177407. In the case where the polymer containing fluorine atoms in (D) includes other repeating units, their content is preferably 50 mol% or less among all the repeating units of the polymer containing fluorine atoms described above.

[0443] (D) Polymers containing fluorine atoms can be synthesized by copolymerizing monomers with protecting groups as needed using known methods, followed by deprotection reactions as required. The copolymerization reaction is not particularly limited, but free radical polymerization and anionic polymerization are preferred. For information on these methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0444] (D) The Mw of the polymer containing fluorine atoms is preferably 2000~50000, more preferably 3000~20000. If the Mw is less than 2000, it may sometimes promote the diffusion of acid, leading to degradation of resolution or impaired stability over time. In addition, the Mw / Mn ratio of the polymer containing fluorine atoms in (D) is preferably 1.0~2.2, more preferably 1.0~1.7.

[0445] In the case where the chemical amplification positive inhibitor composition of the present invention includes (D) a polymer containing fluorine atoms, its content relative to 80 parts by mass of the base polymer (B) is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass. (D) The polymer containing fluorine atoms may be used alone or in combination of two or more.

[0446] [(E) Quenching Agent] The chemically amplified positive resist composition of the present invention may also include a quencher as a component (E) if necessary. In the present invention, a quencher refers to a compound that captures the acid generated by the acid-generating agent. This suppresses the diffusion rate of the acid generated by the acid-generating agent within the resist film, and even when using a substrate with an outermost surface made of a chromium-containing material as the substrate, the effect of the acid generated within the resist film on the chromium-containing material can be suppressed.

[0447] Commonly known basic compounds can be listed as quenching agents. Commonly known basic compounds include first-, second-, and third-order aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, nitrogen-containing compounds with sulfonyl groups, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, amides, and carbamates. In particular, first-, second-, and third-order amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103 are preferred, especially amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, nitrile groups, sulfonate bonds, or compounds having carbamate groups as described in Japanese Patent No. 3790649. Ideal examples include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-nitrogen oxides, dibutylaminobenzoic acid, α-porphyrin derivatives, imidazole derivatives, etc. By adding such basic compounds, for example, the diffusion rate of acid in the resist film can be further suppressed, or the shape can be modified.

[0448] In addition, as the aforementioned quenching agents, examples include strontium salts, ferrous salts, and amine salts of α-unfluorinated carboxylic acids as described in Japanese Patent Application Publication No. 2008-158339. While α-fluorinated sulfonic acids, amide acids, or methyl acids are necessary for deprotecting the unstable acid group, the α-unfluorinated carboxylic acid is released through salt exchange with the α-unfluorinated onmium salt. Since the α-unfluorinated carboxylic acid hardly undergoes a deprotection reaction, it functions as a quenching agent.

[0449] Onium salts of carboxylic acids that are not fluorinated at the α-position can be listed, for example, as shown in the following formula (E1). [Chemistry 322]

[0450] In formula (E1), R201 is a hydrogen atom or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms, except for those in which the hydrogen atom of the carbon atom at the α position of the carboxyl group is substituted with a fluorine atom or a fluorinated alkyl group.

[0451] The hydrocarbon group represented by R201 can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, dibutyl, tributyl, n-pentyl, tripentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, adamantyl, and adamantylmethyl; and vinyl, allyl, propenyl, butenyl, and hexenyl groups with 2 to 40 carbon atoms. Alkenyl groups with 40 carbon atoms; cyclohexenyl and other cyclic unsaturated aliphatic hydrocarbon groups with 3 to 40 carbon atoms; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, 2-phenylethyl, etc.

[0452] In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, nitrile groups, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc. Examples of hydrocarbon groups containing heteroatoms include heteroaryl groups such as thienyl; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; and aryloxyalkyl groups such as 2-phenyl-2-sideoxyethyl, 2-(1-naphthyl)-2-sideoxyethyl, and 2-(2-naphthyl)-2-sideoxyethyl.

[0453] In formula (E1), MqA+ represents an onium cation. Preferably, the onium cation is a strontium cation, a ferrophosphate cation, or an ammonium cation, and more preferably, a strontium cation or a ferrophosphate cation. As a specific example of the strontium cation, the same examples exemplified as those shown as examples of the strontium cation represented by formula (cation-1) can be given. As a specific example of the ferrophosphate cation, the same examples exemplified as those shown as examples of the ferrophosphate cation represented by formula (cation-2) can be given.

[0454] Examples of anions that can be represented as onium salts according to formula (E1) are shown below, but are not limited to these. [Chemistry 323]

[0455] [Chemistry 324]

[0456] [Chemistry 325]

[0457] As the aforementioned quenching agent, strontium salts of carboxylic acids containing iodinated benzene rings, as shown in formula (E2), may also be suitably used. [Chemistry 326]

[0458] In equation (E2), s is an integer from 1 to 5. t is an integer from 0 to 3. However, 1 ≤ s + t ≤ 5. u is an integer from 1 to 3.

[0459] In formula (E2), R211 is a 1-6 carbon saturated hydrocarbon group, a 1-6 carbon saturated hydrocarbon oxygen group, a 2-6 carbon saturated hydrocarbon carbonyl oxygen group, or a 1-4 carbon saturated hydrocarbon sulfonyl oxygen group, or a hydroxyl group, fluorine atom, chlorine atom, bromine atom, amino group, nitro group, cyano group, or a hydrogen atom, which may be partially or wholly substituted by a halogen atom; or -N(R211A)-C(=O)-R211B or -N(R211A)-C(=O)-O-R211B. R211A is a hydrogen atom or a 1-6 carbon saturated hydrocarbon group. R221B is a 1-6 carbon saturated hydrocarbon group or a 2-8 carbon unsaturated aliphatic hydrocarbon group. When t and / or u are 2 or more, each R211 can be the same or different from the others.

[0460] In formula (E2), L11 is a single bond or a (u+1) valence linkage with 1 to 20 carbon atoms, and may also contain at least one selected from ether bonds, carbonyl groups, ester bonds, amide bonds, sulfonyl lactone rings, endamide rings, carbonate bonds, halogen atoms, hydroxyl groups, and carboxyl groups. The aforementioned saturated hydrocarbon groups, saturated hydrocarbon oxy groups, saturated hydrocarbon carbonyl oxy groups, and saturated hydrocarbon sulfonyl oxy groups can be linear, branched, or cyclic.

[0461] In formula (E2), R212, R213, and R214 are each independently a halogen atom or a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms, and aralkyl groups with 7 to 20 carbon atoms. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups can be substituted by hydroxyl, carboxyl, halogen, side oxygen, cyano, nitro, sulfonyl lactone ring, sulfonyl, or strontium salt-containing groups. A portion of the -CH2- group in the aforementioned hydrocarbon groups can also be substituted by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Additionally, R212 and R213 can be bonded to each other and form a ring together with the sulfur atoms they are bonded to.

[0462] As a specific example of a compound represented by formula (E2), the one described in Japanese Patent Application Publication No. 2017-219836 can be cited. The compound represented by formula (E2) has high absorption and high sensitization effect, as well as high acid diffusion control effect.

[0463] As the aforementioned quenching agent, a nitrogen-containing carboxylate type compound as shown in the following formula (E3) can also be used. [Chemistry 327]

[0464] In formula (E3), R221 to R224 each independently represent a hydrogen atom, -L12-CO2-, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. R221 and R222 can also bond to each other with R222 and R223 or R223 and R224 and form a ring with the carbon atoms to which they are bonded. L12 is a single bond or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms. R225 is a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms.

[0465] In formula (E3), ring Rr is a ring containing carbon atoms and nitrogen atoms of 2 to 6 carbons. Some or all of the hydrogen atoms bonded to the carbon atoms of this ring may be replaced by hydrocarbon groups of 1 to 20 carbons, or -L12-CO2-. Some carbon atoms of this ring may also be replaced by sulfur, oxygen, or nitrogen atoms. The aforementioned ring can be an alicyclic or aromatic ring. Preferably, it is a 5-membered or 6-membered ring. Specific examples include pyridine rings, pyrrole rings, pyrrolidine rings, piperidine rings, pyrazole rings, imidazoline rings, pyrazine rings, pyrimidine rings, pyrazine rings, imidazoline rings, pyrazolium rings, thiazole rings, thiozoline rings, thiazoline rings, triazole rings, etc.

[0466] The carboxylate salt represented by formula (E3) has at least one -L12-CO2- group. That is, at least one of R221 to R224 is -L12-CO2- and / or at least one of the hydrogen atoms bonded to the carbon atom of ring Rr is substituted with -L12-CO2-.

[0467] In formula (E3), MqB+ is a strontium cation, a monazine cation, or an ammonium cation, but preferably a strontium cation. As a specific example of the strontium cation mentioned above, the same example as that exemplified as a specific example of a strontium cation represented by formula (cation-1) can be given.

[0468] Examples of anions that can be considered as anions of compounds represented by formula (E3) are shown below, but are not limited to these. [Chemistry 328]

[0469] [Chemistry 329]

[0470] [Chemistry 330]

[0471] [Chemistry 331]

[0472] [Chemistry 332]

[0473] [Chemistry 333]

[0474] Alternatively, weak acid betaine-type compounds can also be used as the aforementioned quenching agents. Specific examples include the substances shown below, but are not limited to these. [Chemistry 334]

[0475] As a further example of the aforementioned quenching agent, a polymer-type quenching agent disclosed in Japanese Patent Application Publication No. 2008-239918 can be cited. It improves the rectangularity of the resist pattern by aligning it on the surface of the resist film. The polymer-type quenching agent also has the effect of preventing film reduction and rounding of the top of the pattern when applying a protective film for immersion exposure.

[0476] When the chemical amplification positive inhibitor composition of the present invention contains (E) quencher, its content relative to 80 parts by weight of the aforementioned base polymer is preferably 0 to 50 parts by weight, and more preferably 0.1 to 40 parts by weight. (E) quencher can be used alone or in combination of two or more.

[0477] When the chemically amplified positive resist composition of the present invention contains both a photoacid generator and a quencher, the content ratio of the photoacid generator to the quencher (photoacid generator / quencher) is preferably less than 3 by mass, more preferably less than 2.5, and even more preferably less than 2. If the content ratio of the photoacid generator to the quencher in the above-mentioned chemically amplified positive resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0478] [(F) Other photoacid generating agents] The chemical amplification positive inhibitor composition of the present invention may also contain photoacid generators other than those composed of onium salts represented by formula (A) and polymer-bonded photoacid generators represented by formulas (B6) to (B9). As for the aforementioned other photoacid generators, there are no particular limitations as long as they are compounds that generate acid by irradiation with high-energy rays. Suitable photoacid generators include strontium salts, monazite salts, sulfonyldiazomethane, N-sulfonoxyimide, oxime-O-sulfonate type acid generators, etc.

[0479] Specific examples of the aforementioned photoacid generators include nonafluorobutane sulfonate, partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of Japanese Patent Application Publication No. 2012-189977, partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of Japanese Patent Application Publication No. 2013-101271, partially fluorinated sulfonates described in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, and photoacid generators described in paragraphs

[0080] to

[0081] of Japanese Patent Application Publication No. 2010-215608. Among the aforementioned specific examples, it is preferable that the aromatic sulfonate type or alkane sulfonate type photoacid generator produces an acid of moderate strength for deprotecting the acid-instable group of the repeating unit B2.

[0480] Salt compounds containing the anions shown below are preferred as such photoacid generators. [Chemistry 335]

[0481] [Chemistry 336]

[0482] [Chemistry 337]

[0483] [Chemistry 338]

[0484] [Chemistry 339]

[0485] [Transformation 340]

[0486] [Chemistry 341]

[0487] [Chemistry 342]

[0488] [Chemistry 343]

[0489] [Chemistry 344]

[0490] [Chemistry 345]

[0491] [Chemistry 346]

[0492] [Chemistry 347]

[0493] [Chemistry 348]

[0494] [Chemistry 349]

[0495] [Chemical 350]

[0496] [Chemistry 351]

[0497] [Chemistry 352]

[0498] [Chemistry 353]

[0499] [Chemistry 354]

[0500] [Chemical 355]

[0501] [Chemical 356]

[0502] [Chemical 357]

[0503] [Chemical 358]

[0504] [Chemical 359]

[0505] [Chemical 360]

[0506] [Chemical 361]

[0507] [Chemical 362]

[0508] [Chemical 363]

[0509] [Chemical 364]

[0510] [Chemical 365]

[0511] [Chemical 366]

[0512] [Chemical 367]

[0513] [Chemical 368]

[0514] [Chemistry 369]

[0515] [Transformation 370]

[0516] [Chemistry 371]

[0517] [Chemistry 372]

[0518] [Chemistry 373]

[0519] [Chemistry 374]

[0520] [Chemistry 375]

[0521] [Chemistry 376]

[0522] [Chemistry 377]

[0523] [Chemistry 378]

[0524] [Chemistry 379]

[0525] [Chemistry 380]

[0526] [Chemistry 381]

[0527] [Chemistry 382]

[0528] [Chemistry 383]

[0529] [Chem. 384]

[0530] [Chem.385]

[0531] [Chemistry 386]

[0532] [Chemistry 387]

[0533] [Chem.388]

[0534] [Chemistry 389]

[0535] [Chemistry 390]

[0536] [Chemistry 391]

[0537] [Chemistry 392]

[0538] [Chemistry 393]

[0539] [Chemistry 394]

[0540] [Chemistry 395]

[0541] Furthermore, as the aforementioned photoacid generator, a salt compound containing an anion represented by the following formula (F1) is also ideal. [Chemistry 396]

[0542] In equation (F1), m1 is 0 or 1. x is an integer from 1 to 3. y is an integer from 1 to 5. z is an integer from 0 to 3. Where 1 ≤ y + z ≤ 5.

[0543] In formula (F1), L21 is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond.

[0544] In formula (F1), L22 is an ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond.

[0545] In formula (F1), LD is a single bond or an extended hydrocarbon group with 1 to 20 carbon atoms when x is 1, and a (x+1) valence hydrocarbon group with 1 to 20 carbon atoms when x is 2 or 3. The aforementioned extended hydrocarbon group and (x+1) valence hydrocarbon group may also contain at least one selected from ether bond, carbonyl group, ester bond, amide bond, sulfonyl lactone ring, amide ring, carbonate bond, halogen atom, hydroxyl group and carboxylic acid group.

[0546] LD indicates that the carbon-1 to 20 carbon-1 hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched or cyclic. Specific examples include alkyl diyl groups with 1 to 20 carbon atoms, such as methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; unsaturated aliphatic hydrocarbon groups with 2 to 20 carbon atoms, such as vinylene and propylene-1,3-diyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; and groups obtained by combining them. Furthermore, the (x+1) valence hydrocarbon group represented by LA, which has 1 to 20 carbon atoms, can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. As a specific example, a group obtained by further removing one or two hydrogen atoms from the above-mentioned examples of hydrocarbon groups with 1 to 20 carbon atoms can be given.

[0547] In formula (F1), Rf21 and Rf22 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, but at least one of them is a fluorine atom or a trifluoromethyl atom.

[0548] In formula (F1), R301 represents a hydroxyl group, a carboxyl group, a saturated hydrocarbon group with 1 to 6 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, -N(R301A)(R301B), -N(R301C)-C(=O)-R301D, or -N(R301C)-C(=O)-O-R301D. R301A and R301B are each independently a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R301C is a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R301D is a saturated hydrocarbon group with 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms.

[0549] R301, R301A, R301B, and R301C represent saturated hydrocarbon groups with 1 to 6 carbon atoms, which can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, and n-hexyl; and cyclic saturated hydrocarbon groups with 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Furthermore, the saturated hydrocarbon base of the saturated hydrocarbon group with 1 to 6 carbon atoms represented by R301 can be the same as the specific examples of the aforementioned saturated hydrocarbon groups. The saturated hydrocarbon base of the saturated hydrocarbon group with 2 to 6 carbon atoms represented by R301 can be those with 1 to 5 carbon atoms among the specific examples of the aforementioned saturated hydrocarbon groups with 1 to 6 carbon atoms.

[0550] R301D represents unsaturated aliphatic hydrocarbon groups with 2 to 8 carbon atoms, which can be linear, branched, or cyclic. Specific examples include alkenyl groups with 2 to 8 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl; alkynyl groups with 2 to 8 carbon atoms such as ethynyl, propynyl, and butynyl; and cyclic unsaturated aliphatic hydrocarbon groups with 3 to 8 carbon atoms such as cyclohexenyl and norcamphenyl.

[0551] In formula (F1), R302 is a saturated hydrocarbon group with 1 to 20 carbon atoms or an aryl group with 6 to 20 carbon atoms. Some or all of the hydrogen atoms of the saturated hydrocarbon group may be replaced by halogen atoms other than fluorine atoms. Some or all of the hydrogen atoms of the aryl group may be replaced by substituents selected from saturated hydrocarbon groups with 1 to 20 carbon atoms, saturated hydrocarbon oxygen groups with 1 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms, halogen atoms and hydroxyl groups.

[0552] The alkyl group with 1 to 20 carbon atoms represented by R302 can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. As a specific example, the same group as the alkyl group with 1 to 20 carbon atoms represented by LD can be cited.

[0553] Specific examples of aryl groups with 6 to 20 carbon atoms represented by R302 include arylphenyl, arylnaphthyl, phenanthrenediyl, and anthracenediyl. The saturated hydrocarbon group with 1 to 20 carbon atoms and the hydrocarbon group with 1 to 20 carbon atoms that are substituents of the aforementioned aryl groups can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; and cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl. Specific examples of aryl groups with 6 to 14 carbon atoms that are substituents of the aforementioned aryl group include: arylphenyl, arylnaphthyl, phenanthrenediyl, anthracenediyl, etc.

[0554] The anion represented by formula (F1) is preferably the anion represented by formula (F2) below. [Chemistry 397]

[0555] In formula (F2), x, y, z, L21, LD, and R301 are as described above. m2 is an integer from 1 to 4. R302A is a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, an aryl group with 6 to 14 carbon atoms, a halogen atom, or a hydroxyl group. It should be noted that when m2 is 2, 3, or 4, each R302A can be the same or different from the others.

[0556] Specific examples of anions represented by formula (F1) can be given by the following anions, but are not limited to these. [Chem.398]

[0557] [Chemistry 399]

[0558] [Chemical 400]

[0559] [Chemical Engineering 401]

[0560] [Chemical 402]

[0561] [Chemical 403]

[0562] [Chemical 404]

[0563] [Chemical 405]

[0564] [Chemical 406]

[0565] [Chemical 407]

[0566] [Chemical 408]

[0567] [Chemical 409]

[0568] [Chemical 410]

[0569] [Chemistry 411]

[0570] [Chemistry 412]

[0571] [Chemistry 413]

[0572] [Chemistry 414]

[0573] [Chemical 415]

[0574] [Chemistry 416]

[0575] [Chemistry 417]

[0576] [Chemistry 418]

[0577] [Chemistry 419]

[0578] [Chemistry 420]

[0579] [Chemistry 421]

[0580] [Chemistry 422]

[0581] [Chemistry 423]

[0582] [Chemistry 424]

[0583] [Chemical 425]

[0584] [Chemistry 426]

[0585] [Chemistry 427]

[0586] [Chemistry 428]

[0587] [Chemistry 429]

[0588] [Chemistry 430]

[0589] [Chemistry 431]

[0590] [Chemistry 432]

[0591] [Chemistry 433]

[0592] [Chemistry 434]

[0593] (F) Among other photoacid generating agents, strontium cations or ferrophosphate cations are preferred as the cation paired with the aforementioned anion. Specific examples of strontium cations may be given as examples similar to those exemplified as strontium cations represented by formula (cation-1), but are not limited to these. Specific examples of ferrophosphate cations may be given as examples similar to those exemplified as ferrophosphate cations represented by formula (cation-2), but are not limited to these.

[0594] The pKa of the acids produced by the aforementioned other photoacid generators is preferably -2.0 or higher, more preferably -1.0 or higher. Furthermore, the upper limit of the pKa is preferably 2.0. It should be noted that the pKa values ​​are calculated using the pKa DB in the software ACD / Chemsketch ver: 9.04 manufactured by Advanced Chemistry Development, Inc.

[0595] When the chemically amplified positive resist composition of the present invention includes (F) other photoacid generating agents, their content is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, relative to 80 parts by mass of the base polymer. By including other photoacid generating agents, the amount of acid generated in the exposed portion and the solubility resistance in the unexposed portion can be appropriately adjusted. (F) Other photoacid generating agents can be used alone or in combination of two or more.

[0596] In addition to the photoacid generator (A), the chemically amplified positive resist composition of the present invention preferably includes a polymer-bonded photoacid generator containing repeating units represented by formulas (B6) to (B9) or (F) other photoacid generators. As a result, the deprotection reaction of the base polymer in the resist film proceeds sufficiently, the pattern shape becomes better, and the resolution is improved.

[0597] (G) Surfactants To improve the coating properties of the substrate, the chemically amplified positive resist composition of the present invention may also contain a conventional surfactant as component (G). Various surfactants are known, as described in International Publication No. 2006 / 121096, Japanese Patent Application Publication No. 2008-102383, Japanese Patent Application Publication No. 2008-304590, Japanese Patent Application Publication No. 2004-115630, and Japanese Patent Application Publication No. 2005-8766, and selection can be made by referring to these.

[0598] When the chemically amplified positive inhibitor composition of the present invention contains (G) surfactant, its content relative to 80 parts by mass of the (B) base polymer is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and the lower limit is preferably 0.01 parts by mass or more. The (G) surfactant can be used alone or in combination of two or more types.

[0599] [Resistant Pattern Formation Method] The resist pattern forming method of the present invention includes: forming a resist film on a substrate using the aforementioned chemically amplified positive resist composition; exposing the aforementioned resist film to high-energy radiation; and developing the resist film irradiated with the aforementioned pattern using an alkaline developer to obtain a resist pattern.

[0600] Examples of substrates used in the aforementioned process include substrates for integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective films, etc.) or substrates for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, etc.). On the aforementioned substrate, the aforementioned chemically amplified positive resist composition is coated with a film thickness of 0.03 μm to 2 μm using a spin-coating or similar method. The substrate is then pre-baked on a hot plate, preferably at 60°C to 150°C for 1 to 20 minutes, more preferably at 80°C to 140°C for 1 to 10 minutes, to form a resist film.

[0601] Next, the resist film is exposed to high-energy rays to irradiate the pattern. Examples of such high-energy rays include ultraviolet light, far-ultraviolet light, excimer laser light (KrF, ArF, etc.), EB, EUV with wavelengths of 3~15nm, X-rays, gamma rays, and synchrotron radiation.

[0602] When using ultraviolet light, far-ultraviolet light, excimer laser light, EUV, X-rays, gamma rays, or synchrotron radiation as the aforementioned high-energy rays, irradiation is performed using a mask for forming the target pattern, with an exposure dose preferably of 1-300 mJ / cm², more preferably 10-200 mJ / cm². When using EB as the high-energy ray, direct drawing is performed with an exposure dose preferably of 1-300 μC / cm², more preferably 10-200 μC / cm². It should be noted that the chemically amplified positive resist composition of the present invention is particularly useful for EUV or EB lithography.

[0603] In addition to the usual exposure method, depending on the situation, an immersion method can also be used, in which a liquid is inserted between the mask and the resist film. In this case, a water-insoluble protective film can also be used.

[0604] Next, perform post-exposure baking (PEB) on a hot plate at a preferred temperature of 60-150°C for 1-20 minutes, or more preferably at 80-140°C for 1-10 minutes.

[0605] Then, using a developer solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1-5% by mass, more preferably 2-3% by mass, development is performed for 0.1-3 minutes, preferably 0.5-2 minutes, using conventional methods such as dip, immersion, or spray, thereby forming the target pattern on the substrate.

[0606] The chemically amplified positive resist composition of the present invention is useful when conditions require particularly high etch resistance and minimal variation in pattern linewidth and low LER even when the time from exposure to PEB is prolonged. Furthermore, the resist composition of the present invention is particularly suitable for substrates with surfaces made of materials that are prone to pattern peeling and pattern breakage due to difficulty in achieving adhesion of the resist pattern. Examples of such substrates include substrates formed by sputtering metallic chromium or chromium compounds containing one or more light elements selected from oxygen, nitrogen, and carbon. The chemically amplified positive resist composition of the present invention is particularly useful for pattern formation using a blank photomask as a substrate. [Example]

[0607] The present invention will now be described in detail with examples of synthesis, embodiments, and comparative examples, but the present invention is not limited to the following embodiments. It should be noted that the apparatus used is as described above. •IR: NICOLET 6700, Thermofisher Scientific ·1H-NMR: ECA-500 manufactured by Nippon Electronics Co., Ltd. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0608] [1] Synthesis of onium salts [Synthetic Example 1-1] Synthesis of PAG-1 [Chemistry 435]

[0609] (1) Synthesis of intermediate In-1 Under a nitrogen atmosphere, starting materials SM-1 (6.3 g), SM-2 (9.8 g), DMAP (0.3 g), and chloromethane (50 g) were added to a reaction vessel and cooled in an ice bath. While maintaining the temperature in the reaction vessel below 20 °C, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (5.8 g) was added in powder form. After addition, the temperature was raised to room temperature and aged for 12 hours. After aging, water was added to stop the reaction, and a conventional aqueous work-up was performed. After distillation to remove the solvent, diisopropyl ether was added, and the residue was washed to obtain 13.9 g of intermediate In-1 (92% yield) as an oil.

[0610] (2) Synthesis of PAG-1 Under a nitrogen atmosphere, intermediate In-1 (13.9 g), starting material SM-3 (7.8 g), chloromethane (50 g), and water (30 g) were added and stirred for 15 minutes. The organic layer was then separated, washed with water, and concentrated under reduced pressure. Methyl isobutyl ketone (50 g) was added to the concentrate for azeotropic dehydration, followed by crystallization with diisopropyl ether, yielding 15.5 g of PAG-1 (92% yield) as white crystals.

[0611] The IR spectral data and TOF-MS results of PAG-1 are shown below. Additionally, the nuclear magnetic resonance spectroscopy (¹H-NMR / DMSO-d⁶) results are shown in Figure 1. IR(D-ATR):ν=3447, 3064, 3022, 2971, 1751, 1626, 1594, 1583, 1507, 1464, 1442, 1379, 1368, 1322, 1272, 12 26, 1204, 1159, 1132, 1113, 1064, 1040, 1021, 998, 905, 886, 832, 816, 762, 706, 684, 632, 601, 577, 534, 493 cm-1 MALDI TOF-MS: POSITIVE M+277 (equivalent to C18H13OS+) NEGATIVE M-455 (equivalent to C27H19O5S-)

[0612] [Synthetic Examples 1-2~1-10] Synthesis of PAG-2~PAG-10 Using the corresponding raw materials and known organic synthesis reactions, the onium salts PAG-2 to PAG-10 represented by the following formulas were synthesized. [Chemistry 436]

[0613] [Chemistry 437]

[0614] [2] Synthesis of basic polymers [Synthetic Examples 2-1~2-6] Synthesis of Basic Polymers (P-1~P-6) The monomers were combined using a known formulation and copolymerized in a solvent. The reaction solution was then added to hexane, and the precipitated solid was washed with hexane, separated, and dried to obtain the basic polymers (P-1 to P-6) with the compositions shown below. The composition of the obtained basic polymers was confirmed by 1H-NMR 13 and C-NMR, and Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene). [Chemistry 438]

[0615] [Chemistry 439]

[0616] [3] Preparation of chemical amplification positive inhibitor composition [Examples 1-1 to 1-53, Comparative Examples 1-1 to 1-28] The components were dissolved in an organic solvent according to the compositions shown in Tables 1-3 below. The resulting solutions were filtered through a nylon filter with a size of 5 nm and a UPE filter with a size of 1 nm, thereby preparing the chemically amplified positive inhibitor composition. It should be noted that the aforementioned organic solvent is a mixture of 940 parts by mass of PGMEA, 1870 parts by mass of EL, and 1870 parts by mass of PGME.

[0617] [Table 1] inhibitor Composition Polymer 1 (parts by weight) Polymer 2 (parts by weight) Photoacid generator (parts by weight) Quenching agent (parts by weight) Fluorine-containing atoms polymer (parts by weight) Example 1-1 R-1 P-1(80) - PAG-1(12) Q-1(7.0) FP-1(1.5) Examples 1-2 R-2 P-1(80) - PAG-1(12) Q-1(7.0) - Examples 1-3 R-3 P-1(80) - PAG-2(12) Q-1(7.0) FP-1(1.5) Examples 1-4 R-4 P-1(80) - PAG-3(12) Q-1(7.0) FP-1(1.5) Examples 1-5 R-5 P-1(80) - PAG-4(12) Q-1(7.0) FP-1(1.5) Examples 1-6 R-6 P-1(80) - PAG-5(12) Q-1(7.0) FP-1(1.5) Examples 1-7 R-7 P-1(80) - PAG-6(12) Q-1(7.0) FP-1(1.5) Examples 1-8 R-8 P-1(80) - PAG-7(12) Q-1(7.0) FP-1(1.5) Examples 1-9 R-9 P-1(80) - PAG-8(12) Q-1(7.0) FP-1(1.5) Examples 1-10 R-10 P-1(80) - PAG-9(12) Q-1(7.0) FP-1(1.5) Examples 1-11 R-11 P-1(80) - PAG-10(12) Q-1(7.0) FP-1(1.5) Examples 1-12 R-12 P-1(80) - PAG-1(8) PAG-A(4) Q-2(7.0) FP-1(1.5) Examples 1-13 R-13 P-1(80) - PAG-2(8) PAG-B(4) Q-4 (7.0) FP-2(1.5) Examples 1-14 R-14 P-1(80) - PAG-3(12) Q-3 (7.0) FP-3(1.5) Examples 1-15 R-15 P-1(80) - PAG-6(12) Q-2(7.0) FP-4(1.5) Examples 1-16 R-16 P-2(80) - PAG-1(12) Q-1(7.0) FP-1(1.5) Examples 1-17 R-17 P-2(80) - PAG-2(12) Q-3 (7.0) FP-1(1.5) Examples 1-18 R-18 P-2(80) - PAG-3(12) Q-1(7.0) FP-1(1.5) Examples 1-19 R-19 P-2(80) - PAG-4(12) Q-4 (7.0) FP-5(1.5) Examples 1-20 R-20 P-2(80) - PAG-6(12) Q-1(7.0) FP-1(1.5) Examples 1-21 R-21 P-2(80) - PAG-8(12) Q-2(7.0) FP-2(1.5) Examples 1-22 R-22 P-2(80) - PAG-10(12) Q-1(7.0) FP-1(1.5) Examples 1-23 R-23 P-2(80) - PAG-1(8) PAG-A(4) Q-1(7.0) FP-1(1.5) Examples 1-24 R-24 P-2(80) - PAG-2(8) PAG-B(4) Q-3 (7.0) FP-2(1.5) Examples 1-25 R-25 P-2(80) - PAG-6(10) PAG-B(2) Q-1(6.8) FP-1(1.5) Examples 1-26 R-26 P-3(80) - PAG-1(12) Q-1(7.0) FP-1(1.5) Examples 1-27 R-27 P-3(80) - PAG-2(12) Q-2(6.8) FP-1(1.5) Examples 1-28 R-28 P-3(80) - PAG-3(12) Q-1(7.0) FP-1(1.5) Examples 1-29 R-29 P-3(80) - PAG-6(12) Q-4 (7.0) FP-3(1.5) Examples 1-30 R-30 P-3(80) - PAG-10(12) Q-1(7.0) FP-1(1.5)

[0618] [Table 2] inhibitor Composition Polymer 1 (parts by weight) Polymer 2 (parts by weight) Photoacid generator (parts by weight) Quenching agent (parts by weight) Fluorine-containing atoms polymer (parts by weight) Examples 1-31 R-31 P-3(80) - PAG-1(8) PAG-A(4) Q-1(7.0) FP-4(1.5) Examples 1-32 R-32 P-4(80) - PAG-1(12) Q-1(7.0) FP-1(1.5) Examples 1-33 R-33 P-4(80) - PAG-2(12) Q-2(6.8) FP-1(1.5) Examples 1-34 R-34 P-4(80) - PAG-4(12) Q-1(7.0) FP-1(1.5) Examples 1-35 R-35 P-4(80) - PAG-5(12) Q-4 (7.0) FP-3(1.5) Examples 1-36 R-36 P-4(80) - PAG-9(12) Q-1(7.0) FP-1(1.5) Examples 1-37 R-37 P-4(80) - PAG-3(8) PAG-B(4) Q-1(7.0) FP-4(1.5) Examples 1-38 R-38 P-5(80) - PAG-1(4) Q-1(7.0) FP-1(1.5) Examples 1-39 R-39 P-5(80) - PAG-2(4) Q-2(7.2) FP-1(1.5) Examples 1-40 R-40 P-5(80) - PAG-6(4) Q-1(7.0) FP-1(1.5) Examples 1-41 R-41 P-5(80) - PAG-8(4) Q-3 (7.0) FP-1(1.5) Examples 1-42 R-42 P-5(80) - PAG-10(4) Q-4(7.4) FP-2(1.5) Examples 1-43 R-43 P-5(80) - PAG-1(3) PAG-A(1) Q-1(7.2) FP-1(1.5) Examples 1-44 R-44 P-6(80) - PAG-1(4) Q-1(7.0) FP-3(1.5) Examples 1-45 R-45 P-6(80) - PAG-2(4) Q-2(7.0) FP-1(1.5) Examples 1-46 R-46 P-6(80) - PAG-4(4) Q-4(7.2) FP-4(1.5) Examples 1-47 R-47 P-6(80) - PAG-7(4) Q-1(7.0) FP-1(1.5) Examples 1-48 R-48 P-6(80) - PAG-9(4) Q-2(7.0) FP-1(1.5) Examples 1-49 R-49 P-6(80) - PAG-1(3) PAG-B(1) Q-1(7.0) FP-1(1.5) Examples 1-50 R-50 P-1(40) P-5(40) PAG-1(4) Q-1(7.0) FP-1(1.5) Examples 1-51 R-51 P-1(40) P-6(40) PAG-2(4) Q-1(7.0) FP-1(1.5) Examples 1-52 R-52 P-2(40) P-5(40) PAG-6(4) Q-2(7.0) FP-1(1.5) Examples 1-53 R-53 P-3(40) P-6(40) PAG-10(4) Q-3 (7.0) FP-1(1.5)

[0619] [Table 3] inhibitor Composition Polymer 1 (parts by weight) Polymer 2 (parts by weight) Photoacid generator (parts by weight) Quenching agent (parts by weight) Fluorine-containing atoms polymer (parts by weight) Comparative Example 1-1 CR-1 P-1(80) - cPAG-1(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-2 CR-2 P-1(80) - cPAG-1(12) Q-1(7.0) - Comparative Examples 1-3 CR-3 P-1(80) - cPAG-2(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-4 CR-4 P-1(80) - cPAG-4(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-5 CR-5 P-1(80) - cPAG-1(8) PAG-A(4) Q-2(7.0) FP-1(1.5) Comparative Examples 1-6 CR-6 P-2(80) - cPAG-1(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-7 CR-7 P-2(80) - cPAG-2(12) Q-3 (7.0) FP-1(1.5) Comparative Examples 1-8 CR-8 P-2(80) - cPAG-3(12) Q-2(7.0) FP-4(1.5) Comparative Examples 1-9 CR-9 P-2(80) - cPAG-2(8) PAG-B(4) Q-3 (7.0) FP-2(1.5) Comparative Examples 1-10 CR-10 P-3(80) - cPAG-1(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-11 CR-11 P-3(80) - cPAG-2(12) Q-2(6.8) FP-1(1.5) Comparative Examples 1-12 CR-12 P-3(80) - cPAG-4(12) Q-4 (7.0) FP-3(1.5) Comparative Examples 1-13 CR-13 P-3(80) - cPAG-1(8) PAG-A(4) Q-1(7.0) FP-4(1.5) Comparative Examples 1-14 CR-14 P-4(80) - cPAG-1(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-15 CR-15 P-4(80) - cPAG-2(12) Q-4 (7.0) FP-3(1.5) Comparative Examples 1-16 CR-16 P-4(80) - cPAG-4(12) Q-1(7.0) FP-1(1.5) Comparative Examples 1-17 CR-17 P-4(80) - cPAG-3(8) PAG-B(4) Q-1(7.0) FP-4(1.5) Comparative Examples 1-18 CR-18 P-5(40) - cPAG-1(4) Q-1(7.0) FP-1(1.5) Comparative Examples 1-19 CR-19 P-5(40) - cPAG-2(4) Q-2(7.2) FP-5(1.5) Comparative Examples 1-20 CR-20 P-5(40) - cPAG-3(4) Q-1(7.0) FP-1(1.5) Comparative Example 1-21 CR-21 P-5(40) - cPAG-1(3) PAG-A(1) Q-1(7.2) FP-1(1.5) Comparative Examples 1-22 CR-22 P-6(40) - cPAG-1(4) Q-1(7.0) FP-3(1.5) Comparative Examples 1-23 CR-23 P-6(40) - cPAG-2(4) Q-2(7.0) FP-1(1.5) Comparative Examples 1-24 CR-24 P-6(40) - PAG-1(3) PAG-B(1) Q-1(7.0) FP-1(1.5) Comparative Examples 1-25 CR-25 P-6(40) - - Q-2(7.0) FP-5(1.5) Comparative Examples 1-26 CR-26 P-1(40) P-5(40) cPAG-1(4) Q-1(7.0) FP-1(1.5) Comparative Examples 1-27 CR-27 P-2(40) P-5(40) cPAG-3(4) Q-2(7.0) FP-1(1.5) Comparative Examples 1-28 CR-28 P-1(40) P-6(40) cPAG-2(2) Q-1(7.0) FP-1(1.5)

[0620] It should be noted that the structures of photoacid generators cPAG-1 to cPAG-4, photoacid generators PAG-A and PAG-B, quenchers Q-1 to Q-4, and fluorine-containing polymers FP-1 to FP-5 are compared in Tables 1 to 3 as follows. [Chemistry 440]

[0621] [Chemistry 441]

[0622] [Chemistry 442]

[0623] [Chemistry 443]

[0624] [4] EB Microfilm Review [Examples 2-1 to 2-53, Comparative Examples 2-1 to 2-28] Using ACT-M (manufactured by Tokyo Power Technology Co., Ltd.), various chemically amplified positive resist compositions (R-1~R-53, CR-1~CR-28) were spin-coated onto a blank mask, which served as a reflective blank mask for EUV exposure. This blank mask consisted of a 284 nm thick Mo / Si40 multilayer reflective film, a 3.5 nm thick Ru film as a protective film, a 70 nm thick TaN film as an absorption layer, and a 6 nm thick CrN film as a hard mask. The resist film was pre-baked at 110°C for 600 seconds on a heated plate to produce an 80 nm thick resist film. The thickness of the obtained resist film was measured using an optical measuring instrument, NanoSpec (manufactured by Nanometrics Co., Ltd.). Measurements were taken at 81 locations on the outer edge of the blank substrate, from the outer perimeter to 10 mm inside, and the average film thickness and film thickness range were calculated.

[0625] Then, the aforementioned resist film was exposed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Inc., with an accelerating voltage of 50kV), and PEB was performed at 110°C for 600 seconds. The film was then developed using a 2.38% by mass TMAH aqueous solution to obtain a positive pattern.

[0626] The obtained resist pattern was evaluated as follows. The patterned blank mask was observed using overhead SEM (scanning electron microscope). The optimal exposure (μC / cm²) was set at a 1:1 line-to-spacing (LS) resolution of 200 nm (1:1 resolution). The minimum size of the exposure at a 1:1 line-to-spacing isolated spacing of 200 nm (9:1 resolution) was taken as the resolution limit (IS resolution). The LER (Lead Reduction) at 200 nm LS was measured using SEM. The pattern shape was visually determined to be rectangular. The results are shown in Tables 4-6.

[0627] [Table 4] inhibitor composition Optimal exposure (µC / cm2) Limiting IS resolution (nm) LER (nm) Pattern Shape Example 2-1 R-1 210 16 4.2 rectangle Example 2-2 R-2 200 17 4.4 rectangle Example 2-3 R-3 205 16 4.3 rectangle Examples 2-4 R-4 210 18 4.3 rectangle Examples 2-5 R-5 215 16 4.4 rectangle Examples 2-6 R-6 210 18 4.3 rectangle Examples 2-7 R-7 215 18 4.4 rectangle Examples 2-8 R-8 220 17 4.2 rectangle Examples 2-9 R-9 210 16 4.2 rectangle Example 2-10 R-10 215 18 4.4 rectangle Example 2-11 R-11 215 16 4.4 rectangle Example 2-12 R-12 210 17 4.4 rectangle Example 2-13 R-13 215 18 4.3 rectangle Example 2-14 R-14 210 16 4.2 rectangle Example 2-15 R-15 215 17 4.5 rectangle Example 2-16 R-16 210 17 4.2 rectangle Example 2-17 R-17 215 16 4.3 rectangle Example 2-18 R-18 210 18 4.5 rectangle Example 2-19 R-19 210 16 4.3 rectangle Example 2-20 R-20 200 17 4.5 rectangle Example 2-21 R-21 210 18 4.3 rectangle Example 2-22 R-22 215 16 4.3 rectangle Example 2-23 R-23 210 18 4.4 rectangle Example 2-24 R-24 215 17 4.4 rectangle Example 2-25 R-25 210 17 4.3 rectangle Example 2-26 R-26 215 16 4.2 rectangle Example 2-27 R-27 215 18 4.3 rectangle Example 2-28 R-28 205 17 4.2 rectangle Example 2-29 R-29 200 16 4.4 rectangle Examples 2-30 R-30 205 18 4.4 rectangle

[0628] [Table 5] inhibitor composition Optimal exposure (µC / cm2) Limiting IS resolution (nm) LER (nm) Pattern Shape Example 2-31 R-31 210 16 4.4 rectangle Example 2-32 R-32 215 18 4.3 rectangle Example 2-33 R-33 210 16 4.3 rectangle Examples 2-34 R-34 215 16 4.2 rectangle Example 2-35 R-35 220 17 4.4 rectangle Examples 2-36 R-36 215 16 4.2 rectangle Example 2-37 R-37 210 17 4.3 rectangle Example 2-38 R-38 205 18 4.3 rectangle Example 2-39 R-39 215 17 4.3 rectangle Example 2-40 R-40 210 18 4.3 rectangle Example 2-41 R-41 215 16 4.2 rectangle Example 2-42 R-42 205 18 4.4 rectangle Examples 2-43 R-43 200 16 4.3 rectangle Example 2-44 R-44 215 16 4.3 rectangle Example 2-45 R-45 215 17 4.2 rectangle Example 2-46 R-46 210 16 4.3 rectangle Example 2-47 R-47 215 17 4.2 rectangle Example 2-48 R-48 205 18 4.3 rectangle Example 2-49 R-49 215 16 4.4 rectangle Example 2-50 R-50 210 17 4.2 rectangle Example 2-51 R-51 215 16 4.3 rectangle Example 2-52 R-52 200 17 4.3 rectangle Examples 2-53 R-53 215 16 4.2 rectangle

[0629] [Table 6] inhibitor composition Optimal exposure (µC / cm2) Limiting IS resolution (nm) LER (nm) Pattern Shape Comparative Example 2-1 CR-1 215 20 4.9 rectangle Comparative Example 2-2 CR-2 200 twenty one 4.9 Trail Comparative Examples 2-3 CR-3 200 twenty two 5.1 rectangle Comparative Examples 2-4 CR-4 215 twenty one 4.8 rectangle Comparative Examples 2-5 CR-5 205 20 5.1 Trail Comparative Examples 2-6 CR-6 210 twenty three 5 rectangle Comparative Examples 2-7 CR-7 200 twenty two 4.9 Trail Comparative Examples 2-8 CR-8 210 twenty three 4.7 rectangle Comparative Examples 2-9 CR-9 210 twenty three 4.8 rectangle Comparative Example 2-10 CR-10 210 twenty one 4.9 rectangle Comparative Example 2-11 CR-11 215 20 5 rectangle Comparative Example 2-12 CR-12 210 twenty two 4.9 Trail Comparative Example 2-13 CR-13 210 twenty three 4.7 rectangle Comparative Example 2-14 CR-14 210 twenty four 4.8 rectangle Comparative Example 2-15 CR-15 215 twenty three 5 Trail Comparative Example 2-16 CR-16 210 twenty two 4.8 rectangle Comparative Example 2-17 CR-17 215 twenty two 4.7 rectangle Comparative Example 2-18 CR-18 200 twenty one 4.9 Trail Comparative Example 2-19 CR-19 210 twenty three 4.8 rectangle Comparative Example 2-20 CR-20 215 twenty one 5 rectangle Comparative Example 2-21 CR-21 200 twenty one 4.9 rectangle Comparative Example 2-22 CR-22 205 twenty three 5 Trail Comparative Example 2-23 CR-23 215 twenty four 4.8 rectangle Comparative Example 2-24 CR-24 200 twenty four 4.7 rectangle Comparative Example 2-25 CR-25 205 twenty two 5 Trail Comparative Example 2-26 CR-26 215 20 4.8 rectangle Comparative Example 2-27 CR-27 200 20 4.9 Trail Comparative Example 2-28 CR-28 205 20 4.7 rectangle

[0630] The results shown in Tables 4-6 indicate that the photoacid generator containing the onium salt of formula (A), the chemically amplified positive resist composition using it, and the resist patterning method are useful for photolithography in semiconductor device manufacturing, especially in the processing of transmissive and reflective blank photomasks.

Claims

1. A chemically amplified positive inhibitor composition comprising: (A) a photoacid generator consisting of an onium salt represented by formula (A), and (B) a base polymer comprising a repeating unit represented by formula (B1) that decomposes under acid and increases solubility in an alkaline developer. In the formula, R1 to R12 each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms. However, one of R1 and R2, and one of R3 and R4, are bonded to each other and together with the carbon atoms they are bonded to form a benzene ring, and one of R6 and R7, and one of R8 and R9, are bonded to each other and together with the carbon atoms they are bonded to form a benzene ring; or one of R1 and R2, and one of R3 and R4, are bonded to each other and together with the carbon atoms they are bonded to form a cyclohexane ring, and one of R6 and R7, and one of R8 and R9, are bonded to each other and together with the carbon atoms they are bonded to form a cyclohexane ring; one of R13 and R14 is a group having the substructure shown in formula (a) below, and the other is a hydrogen atom, a halogen atom, or a hydrocarbon group with 1 to 20 carbon atoms that may also contain heteroatoms; Z+ is an onium cation. In the formula, m1 is 0 or 1; m2 is an integer from 0 to 4 when m1 is 0, and an integer from 0 to 6 when m1 is 1; m3 is an integer from 0 to 3 when m1 is 0, and an integer from 0 to 5 when m1 is 1; however, m2 + m3 is 0 to 4 when m1 is 0, and 0 to 6 when m1 is 1; RF is a fluorine atom, a fluorinated alkyl group with 1 to 6 carbon atoms, a fluorinated alkoxy group with 1 to 6 carbon atoms, or a fluorinated alkylthio group with 1 to 6 carbon atoms; however, RF is not a fluorine atom when m1=0 and m2=4, and RF is not a fluorine atom when m1=1 and m2=6; R15 is a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; when m3 is 2 or more, multiple R15 groups may bond to each other and form a ring with the carbon atoms they are bonded to; LA is an ester bond; LB is a single bond, ether bond, ester bond, or sulfonate bond. XL is a single bond or a carbonyl group with 1 to 40 carbon atoms that may contain heteroatoms. In the formula, a1 is 0 or 1, a2 is an integer from 0 to 2, a3 is an integer satisfying 0≤a3≤5+2(a2)-a4, a4 ​​is an integer from 1 to 3, RA is a hydrogen atom, a fluorine atom, a methyl or trifluoromethyl atom, R21 is a halogen atom, or a saturated hydrocarbon group with 1 to 6 carbon atoms that may be substituted by a halogen atom, or a saturated hydrocarbon carbonyl group with 2 to 8 carbon atoms that may be substituted by a halogen atom, A1 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group may also be substituted by -O-.

2. As in claim 1, the chemical amplification positive inhibitor composition, wherein, The onium salt is represented by the following formula (A1), in which R1 to R13, LA, XL, RF, R15, m1 to m3 and Z+ are as described in claim 1.

3. The chemical amplification positive inhibitor composition as described in claim 2, wherein, The onium salt is represented by the following formula (A2), in which R5, R10 to R13, R15, LA, XL, RF, m1 to m3 and Z+ are as described in claim 1, m4 and m5 are each independently 0, R16 and R17 are each independently hydrogen atoms, halogen atoms, or hydrocarbon groups with 1 to 20 carbon atoms that may also contain heteroatoms. In addition, when m4 is 2 or more, multiple R16s can bond to each other and form a ring together with the carbon atoms they are bonded to, or together with the carbon atoms they are bonded to and the carbon atoms between them. When m5 is 2 or more, multiple R17s can bond to each other and form a ring together with the carbon atoms they are bonded to, or together with the carbon atoms they are bonded to and the carbon atoms between them.

4. The chemical amplification positive inhibitor composition as described in claim 1, wherein, Z+ is a strontium cation as shown in formula (cation-1) or a monium cation as shown in formula (cation-2), wherein Rct1 to Rct5 are each independently a halogen atom or a hydrocarbon group with 1 to 30 carbon atoms that may contain heteroatoms. In addition, Rct1 and Rct2 may also be bonded to each other and form a ring together with the sulfur atoms they are bonded to.

5. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer further contains repeating units represented by the following formula (B2-1), where RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; b1 is 0 or 1; b2 is an integer from 0 to 2; b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2b2 - b4; b4 is an integer from 1 to 3; b5 is 0 or 1; R31 is a halogen atom, a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted by a halogen atom; A2 is a single bond or a 1-10 carbon saturated hydrocarbon group, part of which -CH2- can also be substituted by -O-; X is an acid-unstable group when b4 is 1, and a hydrogen atom or an acid-unstable group when b4 is 2 or 3, but at least one of them is an acid-unstable group.

6. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer also contains repeating units as shown in formula (B2-2), where c1 is an integer from 0 to 2, c2 is an integer from 0 to 2, c3 is an integer from 0 to 5, c4 is an integer from 0 to 2, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, R32 and R33 are each independently a hydrocarbon group having 1 to 10 carbon atoms, which may also contain heteroatoms, and R32 and R33 may also be bonded to each other and form a ring with the carbon atoms to which they are bonded, R34 is each independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms, and R35 is each independently a hydrocarbon group having 1 to 10 carbon atoms, which may also contain heteroatoms. A3 represents a single bond, phenyl, naphthyl, or *-C(=O)-O-A31-, where A31 is an aliphatic alkyl group with 1 to 20 carbon atoms that may contain a hydroxyl group, ether bond, ester bond, or lactone ring, or a phenyl or naphthyl group, and * is an atomic bond between the carbon atoms of the main chain and the main chain.

7. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer contains at least one repeating unit selected from the repeating units represented by formula (B3), formula (B4), and formula (B5) below, where d is an integer from 0 to 6, e is an integer from 0 to 4, f1 is 0 or 1, f2 is an integer from 0 to 2, f3 is an integer from 0 to 5, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R41 and R42 are each independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group having 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms that can be substituted by a halogen atom. R43 is a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, a saturated hydrocarbon oxy hydrocarbon group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a cyano group. When f2 is 1 or 2, it can be a hydroxyl group. A4 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. Part of the -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

8. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer contains at least one repeating unit selected from the following formulas (B6, B7, B8, and B9), wherein RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X1 is a single bond or a phenyl group; X2 is *1-C(=O)-O-X21-, *1-C(=O)-NH-X21-, or *1-O-X21-, where X21 is an aliphatic alkyl group, a phenyl group, or a divalent group obtained by combining them, having 1 to 6 carbon atoms; it may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; and *1 is an atomic bond with X1. X3 can be a single bond, an enylphenyl group, an enylnaphthyl group, or *2-C(=O)-O-X31-, where X31 is an aliphatic enyl group, enylphenyl group, or enylnaphthyl group with 1 to 10 carbon atoms. This aliphatic enyl group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. *2 indicates an atomic bond with a carbon atom in the main chain. X4 can be a single bond, *3-X41-C(=O)-O-, *3-C(=O)-NH-X41-, or *3-O-X41-, where X41 is an enyl group with 1 to 20 carbon atoms and may also contain heteroatoms. *3 indicates an atomic bond with X3. X5 can independently represent a single bond, *4-X51-C(=O)-O-, *4-C(=O)-NH-X51-, or *4-O-X51-, where X51 is a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. *4 indicates an atomic bond with X4. X6 can represent a single bond, methylene, ethyl, phenyl, fluorinated phenyl, phenyl substituted with trifluoromethyl, *2-C(=O)-O-X61-, *2-C(=O)-N(H)-X61-, or *2-O-X61-, where X61 is an aliphatic hydrocarbon group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or phenyl substituted with trifluoromethyl. It may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. *2 indicates an atomic bond with a carbon atom in the main chain. R51 and R52 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. In addition, R51 and R52 may also be bonded to each other and form a ring with the sulfur atoms they are bonded to. L1 is a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, carbonate bond or carbamate bond. Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms. Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms. Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom or a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms. However, all Rf5 and Rf6 are not hydrogen atoms at the same time. M- is a non-nucleophilic opposite ion. A+ is an onium cation. g1 and g2 are each independently an integer from 0 to 3.

9. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, Of all the repeating units in the base polymer, the content of repeating units with an aromatic ring skeleton is more than 60 mol%.

10. The chemically amplified positive inhibitor composition of claim 1 further contains (C) an organic solvent.

11. The chemical amplification positive inhibitor composition of claim 1 further comprises (D) a fluorinated polymer containing at least one repeating unit selected from the repeating units represented by formula (D1), formula (D2), formula (D3), and formula (D4) below, and may further comprise at least one repeating unit selected from the repeating units represented by formula (D5) and formula (D6) below, wherein j1 is an integer from 1 to 3, j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1, j3 is 0 or 1, k is an integer from 1 to 3, RB is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, RC is independently a hydrogen atom or a methyl group, and R101, R102, R104, and R105 are independently hydrogen atoms or saturated hydrocarbon groups having 1 to 10 carbon atoms. R103, R106, R107, and R108 are each independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group with 1 to 15 carbon atoms, or an acid-unstable group. When R103, R106, R107, and R108 are hydrocarbon groups or fluorinated hydrocarbon groups, an ether bond or a carbonyl group can be inserted between carbon-carbon bonds. R109 is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have a heteroatom inserted between carbon-carbon bonds. R110 is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, which may have a heteroatom inserted between carbon-carbon bonds. R111 is a saturated hydrocarbon group with 1 to 20 carbon atoms, in which at least one hydrogen atom is replaced by a fluorine atom, and part of the -CH2- of this saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. Z1 is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms; Z2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-, where * represents an atomic bond with a carbon atom in the main chain; Z3 represents a single bond, -O-, *-C(=O)-O-Z31-Z32- or *-C(=O)-NH-Z31-Z32-, where Z31 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms; Z32 is a single bond, ester bond, ether bond, or sulfonamide bond, where * represents an atomic bond with a carbon atom in the main chain.

12. The chemical amplification positive inhibitor composition of claim 1 further contains (E) a quencher.

13. The chemical amplification positive inhibitor composition as claimed in claim 12, wherein, (A) The ratio of photoacid generator to (E) quencher is less than 3 by mass.

14. The chemical amplification positive inhibitor composition of claim 1 further contains a photoacid generator other than a photoacid generator composed of an onium salt represented by formula (A).

15. A method for forming a resist pattern, comprising: The step of forming a resist film on a substrate using a chemically amplified positive resist composition as described in any of claims 1 to 14; The steps of irradiating the resist film with high-energy rays to form a pattern, and developing the irradiated resist film with an alkaline developer.

16. The method for forming a resist pattern as described in claim 15, wherein, The high-energy rays are extreme ultraviolet rays or electron beams with wavelengths of 3–15 nm.

17. The method for forming a resist pattern as described in claim 15, wherein, The outermost surface of the substrate is made of a chromium-containing material.

18. The method for forming a resist pattern as described in claim 15, wherein, The substrate is a blank photomask.

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