Chemically amplified positive resist composition and resist pattern forming process

Abstract

The present invention addresses the problem of providing a chemically amplified positive resist composition that exhibits good solvent solubility, excellent lithography performance (such as resolution, LER, and pattern shape) in photolithography using high-energy rays, while also demonstrating resistance to pattern collapse and excellent etching resistance during fine pattern formation, and a pattern formation method using the chemically amplified positive resist composition. The present invention provides a chemically amplified positive resist composition comprising: a base polymer (A), which is a polymer whose solubility in alkaline aqueous solutions increases due to the action of acid; the base polymer comprising: repeating units consisting of an aromatic sulfonic acid anion represented by formula (A1-1) and a strontium cation represented by formula (A1-2), and repeating units represented by formula (A2), and which exhibits increased solubility in alkaline aqueous solutions due to the action of acid.

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, the increasing integration of integrated circuits has necessitated the formation of finer patterns. Patterns smaller than 0.2 μm are primarily fabricated using chemically amplified resist compositions with acid as a catalyst. Exposure sources in this process utilize high-energy rays such as ultraviolet light, far-ultraviolet light, and electron beams (EB). EB lithography, in particular, is indispensable for the fabrication of blank photomasks in semiconductor manufacturing, especially as it is used in ultra-fine processing techniques. The resist compositions used in such photolithography include positive types that dissolve the exposed area to form a pattern, and negative types that leave the exposed area intact to form a pattern. These can be easily selected by the user to suit the desired resist pattern morphology.

[0003] Generally, the etched pattern (EB) is created without a mask. For positive patterns, the area outside the desired resist film is sequentially irradiated with a fine-area EB. For negative patterns, the area where the resist film is to be left is irradiated sequentially. This is a sweeping operation across the entire finely segmented area of ​​the processing surface, making it more time-consuming than a single exposure using a photomask. To avoid reducing throughput, the resist film requires high sensitivity. Furthermore, the longer etch time easily leads to differences between the initial and later etched areas; the duration stability of the exposure in a vacuum is a crucial performance requirement. Moreover, in the particularly important application of blank photomasks, surface materials such as chromium compound films (e.g., chromium oxide on the photomask substrate) can easily affect the pattern shape of the chemically amplified resist film. To maintain high resolution and preserve the etched shape, regardless of the substrate type, maintaining the resist film pattern outline as rectangular is also an important performance characteristic.

[0004] The sensitivity and pattern profile control of the aforementioned resist films have been improved through various modifications, including the selection and combination of materials used in the resist composition and processing conditions. One such improvement addresses the issue of acid diffusion, which significantly affects the resolution of chemically amplified resist films. Photomask processing requires that the shape of the resist pattern obtained does not change over time up to post-exposure heating (PEB). The large time-dependent variation is due to acid diffusion caused by exposure. This acid diffusion problem is not limited to photomask processing; it also significantly affects sensitivity and resolution in general resist compositions, hence much research has been conducted.

[0005] Patent documents 1 and 2 describe examples of suppressing acid diffusion and reducing roughness by increasing the volume of acid generated by an acid-generating agent. However, the suppression of acid diffusion is insufficient in such acid-generating agents, so it is desirable to develop acid-generating agents with smaller diffusion.

[0006] Furthermore, patent documents 3-6 describe examples of controlling acid diffusion by incorporating sulfonic acid generated during exposure into a resin used in an inhibitor composition. This method of suppressing acid diffusion by introducing repeating units that generate acid during exposure into a base polymer is effective in obtaining patterns with low line edge roughness (LER). However, depending on the structure and incorporation rate of these repeating units, there are also cases where the solubility of the base polymer containing these repeating units in organic solvents becomes problematic.

[0007] Additionally, polymers with a large number of aromatic backbones with acidic side chains, such as polyhydroxystyrene, are used as resist compositions for KrF lithography. However, they exhibit significant absorption for light around 200 nm, so they are not used as resist compositions for ArF lithography. Nevertheless, for resist compositions for EB lithography and extreme ultraviolet (EUV) lithography, which are powerful techniques for forming patterns with smaller processing limits than ArF lithography, materials with high etch resistance are important considerations.

[0008] Regarding the base polymers of resist compositions for positive EB lithography and EUV lithography, the primary method uses acid generated from a photoacid generator by irradiation with high-energy rays as a catalyst. This acid-indestructible protecting groups (acid-decomposing protecting groups) deprotect the acidic functional groups of the phenol side chains of the base polymer, making the material soluble in alkaline developers. The aforementioned acid-indestructible protecting groups mainly include tertiary alkyl groups, tert-butoxycarbonyl groups, and acetal groups. While using protecting groups with lower activation energies for deprotection, such as acetal groups, can yield highly sensitive resist films, insufficient suppression of acid diffusion can lead to deprotection reactions in unexposed areas of the resist film, resulting in LER degradation and a decrease in pattern linewidth uniformity (CDU).

[0009] With the increasing miniaturization of resist patterns in recent years, issues such as pattern collapse during development and poor resistance during etching have become problems. While the introduction of repeating units that generate acid during exposure has somewhat suppressed acid diffusion, there is still room for improvement in various lithography properties, resist pattern collapse, and etching resistance. To meet future miniaturization requirements, the development of polymer-based acid generators that balance lithography performance with resist pattern collapse and etching resistance is crucial. [Previous Technical Documents] [Patent Literature]

[0010] [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 No. 4425776 [Patent Document 4] Japanese Patent No. 5201363 [Patent Document 5] Japanese Patent No. 5231357 [Patent Document 6] International Publication No. 2008 / 081832 Summary of the Invention

[0011] [The problem that the invention aims to solve] In recent years, there has been a demand not only for line spacing (LS), isolated lines (IL), and isolated spacing (IS), but also for resist compositions with excellent hole pattern shape and excellent etching resistance after pattern formation.

[0012] In view of the foregoing circumstances, the present invention aims to provide a chemical amplifying positive resist composition that exhibits good solvent solubility, excellent lithography properties such as resolution, LER, and pattern shape, especially in photolithography using high-energy rays such as KrF excimer laser, ArF excimer laser, EB, and EUV, while also resisting pattern collapse and exhibiting excellent etching resistance during fine pattern formation, and a pattern formation method using the chemical amplifying resist composition. [Methods for solving problems]

[0013] In order to achieve the aforementioned objectives, the inventors of this invention conducted repeated and in-depth research and discovered that, as a polymer-bonded acid generator, a polymer containing repeating units of onium salts with polymerizable aromatic sulfonic acid anions and triaryl strontium cations with iodine atoms on the aromatic rings, as well as repeating units with phenolic hydroxyl groups, is used as a chemical amplification positive inhibitor composition. This results in good solvent solubility, excellent lithography properties such as resolution, LER, and pattern shape, especially under EB and EUV lithography. At the same time, it resists pattern collapse during the formation of fine patterns and has excellent etching resistance, thus completing this invention.

[0014] 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: The basic polymer (A) is a polymer whose solubility in alkaline aqueous solutions increases due to the action of acid. It comprises repeating units consisting of an aromatic sulfonic acid anion represented by formula (A1-1) and a strontium cation represented by formula (A1-2), and repeating units represented by formula (A2), and exhibits increased solubility in alkaline aqueous solutions due to the action of acid. [Chemistry 1] In the formula, n1 is 0 or 1, n2 is 0, 1, 2, 3 or 4 when n1 is 0, and 0, 1, 2, 3, 4, 5 or 6 when n1 is 1. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, R1 can be a halogen atom, nitro group, cyano group, hydroxyl group, or a hydrocarbon group with 1-20 carbon atoms (heteroatomic), an alkyloxy group with 1-20 carbon atoms (heteroatomic), or a alkylthio group with 1-20 carbon atoms (heteroatomic). When n2 is 2 or more, each R1 can be the same or different from the others. Multiple R1s can also bond to each other and form a ring together with the carbon atoms they are bonded to. X1 series single bonds, ether bonds, ester bonds, or amide bonds, [Chemistry 2] In the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, only m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and, m4 + m12 ≥ 1. RF1 to RF3 are each independently a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms. When m5 is 2 or more, each RF1 can be the same or different from the others. When m6 is 2 or more, each RF2 can be the same or different from the others. When m7 is 2 or more, each RF3 can be the same or different from the others. R2~R5 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or can include hydrocarbon groups with 1~20 carbon atoms (heteroatomic), hydroxyl groups with 1~20 carbon atoms (heteroatomic), or thiol groups with 1~20 carbon atoms (heteroatomic). When m8 is 2, the two R2 atoms can be the same or different, and can also bond to each other and form a ring with the carbon atoms they are bonded to. When m9 is 2, the two R3 atoms can be the same or different, and can also bond to each other and form a ring with the carbon atoms they are bonded to. When m10 is 2, the two R4 atoms can be the same or different, and can also bond to each other and form a ring with the carbon atoms they are bonded to. When m13 is 2, the two R5 atoms can be the same or different, and can also bond to each other and form a ring with the carbon atoms they are bonded to. Furthermore, the aromatic rings directly bonded to S+ in the strontium cation can also bond to each other and form rings together with S+. LA and LB are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. XL series single bonds, or may also contain heteroatoms and carbon groups with 1 to 40 carbon atoms, [Chemistry 3] In the formula, a1 is 0 or 1, a2 is 0, 1 or 2, a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4, and a4 is 1, 2 or 3. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, R11 refers to halogen atoms, saturated hydrocarbon groups with 1 to 6 carbon atoms that can be substituted with halogen atoms, saturated hydrocarbon oxygen groups with 1 to 6 carbon atoms that can be substituted with halogen atoms, or saturated hydrocarbon carbonyl oxygen groups with 2 to 8 carbon atoms that can be substituted with halogen atoms. A1 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms. The -CH2- of this saturated alkyl group can also be replaced by -O-. 2. As in 1., the chemically amplified positive inhibitor composition, wherein the strontium cation represented by formula (A2) is represented by formula (A1-2-1), [Chemistry 4] In the formula, m4~m10, m12~m14, RF1~RF3, R2~R5, LA, LB and XL are the same as those mentioned above. 3. As in 2., the chemically amplified positive inhibitor composition, wherein the strontium cation system represented by formula (A1-2-1) is represented by formula (A1-2-2). [Chemistry 5] In the formula, m4~m10, RF1~RF3 and R2~R5 are the same as those mentioned above. 4. A chemically amplifying positive inhibitor composition as described in any of 1 to 3, wherein the repeating unit represented by formula (A2) is represented by formula (A2-1). [Chemistry 6] In the formula, RA and a4 are the same as those mentioned above. 5. A chemically amplified positive inhibitor composition as described in any one of 1 to 4, wherein the polymer further comprises at least one repeating unit selected from the repeating units represented by formula (A3-1) and formula (A3-2). [Chemistry 7] In the formula, b1 is 0 or 1, b2 is 0, 1 or 2, b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4, b4 is 1, 2 or 3, and b5 is 0 or 1. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, R12 refers to halogen atoms, saturated hydrocarbon groups with 1 to 6 carbon atoms that can be substituted with halogen atoms, saturated hydrocarbon oxygen groups with 1 to 6 carbon atoms that can be substituted with halogen atoms, or saturated hydrocarbon carbonyl oxygen groups with 2 to 8 carbon atoms that can be substituted with halogen atoms. The A2 group consists of a single bond or a saturated alkyl group with 1 to 10 carbon atoms. A portion of the -CH2- group in this saturated alkyl group can also be replaced by -O-. When b4 is 1, X is an unstable acid group; when b4 is 2 or 3, X is either a hydrogen atom or an unstable acid group independently, but at least one of them is an unstable acid group. c1 series: 0, 1, or 2; c2 series: 0, 1, or 2; c3 series: 0, 1, 2, 3, 4, or 5; c4 series: 0, 1, or 2. R13 and R14 are each independently hydrocarbon groups with 1 to 10 carbon atoms, and may also contain heteroatoms. R13 and R14 can also bond with each other and form a ring together with the carbon atoms they are bonded to. R15 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. R16 can be an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. A3 is a single bond, phenyl, naphthyl or *-C(=O)-O-A31-, where A31 is an aliphatic alkyl group, phenyl or naphthyl group with 1 to 20 carbon atoms. The aliphatic alkyl group may also include at least one selected from hydroxyl, ether, ester and lactone rings. * indicates an atomic bond with a carbon atom of the main chain. 6. A chemically amplified positive inhibitor composition as described in any one of 1 to 5, wherein the polymer further comprises at least one repeating unit selected from the repeating units represented by formula (B3), formula (B4), and formula (B5). [Chemistry 8] In the formula, d represents 0, 1, 2, 3, 4, 5, or 6; e represents 0, 1, 2, 3, or 4; f1 represents 0 or 1; f2 represents 0, 1, or 2; and f3 represents 0, 1, 2, 3, 4, or 5. RA series: hydrogen atom, fluorine atom, methyl or trifluoromethyl, R17 and R18 are each independently a hydroxyl group, a halogen atom, a 1-6 carbon saturated hydrocarbon group that can be substituted with a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted with a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted with a halogen atom. R19 series includes halogen atoms, nitro groups, cyano groups, saturated hydrocarbon groups with 1-20 carbon atoms, saturated hydrocarbon oxygen groups with 1-20 carbon atoms, saturated hydrocarbon carbonyl oxygen groups with 2-20 carbon atoms, saturated hydrocarbon oxygen groups with 2-20 carbon atoms, or saturated hydrocarbon thioalkyl groups with 2-20 carbon atoms. When f2 is 1 or 2, it can also be a hydroxyl group. The A4 group consists of a single bond or a saturated alkyl group with 1 to 10 carbon atoms. The -CH2- of this saturated alkyl group can also be replaced by -O-. 7. A chemically amplified positive inhibitor composition as described in any one of 1 to 6, wherein the content of repeating units having an aromatic ring skeleton in all repeating units of the (A) base polymer is 60 mol% or more. 8. Any chemical amplification positive inhibitor composition as described in any of 1 to 7, further comprising (B) a quencher. 9. The chemical amplification positive inhibitor composition of any one of 1 to 8 further includes (C) an organic solvent. 10. The chemical amplification positive inhibitor composition of any one of 1 to 9, further comprising (D) a polymer containing fluorine atoms, wherein the (D) fluorine-containing polymer comprises: The repeating unit is selected from at least one of the repeating units represented by the following formula (D1), the following formula (D2), the following formula (D3), and the following formula (D4). [Chemistry 9] In the formula, h is 1, 2, or 3. Each of RB is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R201, R202, R204, and R205 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R203, R206, R207, and R208 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 R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, an ether bond or a carbonyl group can also be inserted between the carbon-carbon bonds. Z1 series: (h+1) valence hydrocarbon groups with 1 to 20 carbon atoms or (h+1) valence fluorinated hydrocarbon groups with 1 to 20 carbon atoms. 11. The chemically amplified positive inhibitor composition of 10, wherein the fluorine-containing polymer further comprises at least one repeating unit selected from the repeating units represented by formula (D5) and formula (D6). [Chemistry 10] In the formula, x is 1, 2, or 3; y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x; and z is 0 or 1. RC can be independently represented by a hydrogen atom or a methyl group. R209 can be a hydrogen atom, or a straight-chain or branched hydrocarbon group containing heteroatoms inserted between carbon-carbon bonds, consisting of 1 to 5 carbon atoms. The R210 series can also insert straight-chain or branched hydrocarbon groups with 1 to 5 carbon atoms containing heteroatoms between carbon-carbon bonds. R211 is a saturated hydrocarbon group with 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom. The -CH2- portion of this saturated hydrocarbon group may also be replaced by an ester or ether bond. Z2-series single bonds, *-C(=O)-O- or *-C(=O)-NH-, Z3 series: single bond, -O-, *-C(=O)-O-Z31-Z32- or *-C(=O)-NH-Z31-Z32-, where Z31 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and Z32 is a single bond, ester bond, ether bond, or sulfonamide bond. *The bonds between the carbon atoms in the main chain and the atoms in the main chain. 12. Any chemical amplification positive inhibitor composition as described in any of 1 to 11, further comprising (E) an acid generating agent. 13. A method for forming a resist pattern, comprising the following steps: A resist film is formed on a substrate using any of the chemically amplified positive resist compositions described in 1 to 12, the resist film is patterned using high-energy rays, and the patterned resist film is developed using an alkaline developer. 14. The resist pattern forming method of 13, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, extreme ultraviolet light, or an electron beam. 15. The resist patterning method of 13 or 14, wherein the outermost surface of the substrate is composed of a material containing at least one selected from chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten and tin. 16. A resist pattern forming method according to any one of 13 to 15, wherein the substrate is a transmissive or reflective blank mask. 17. A transmissive or reflective blank mask, formed by coating a chemically amplified positive resist composition as described in any one of 1 to 12. [Effects of the Invention]

[0015] The chemically amplified positive resist composition of this invention exhibits extremely high resolution in microfabrication technologies, especially EB lithography and EUV lithography, and can provide patterns with small LER (Low Etching Reduction). Furthermore, due to its excellent etch resistance after pattern formation, it is suitable as a chemically amplified positive resist material. Simple Explanation of the Diagram

[0016] [Figure 1] is the nuclear magnetic resonance spectrum (1H-NMR / DMSO-d6) of the onium salt type monomer A1-1 synthesized in Synthesis Example 1-1. Implementation

[0017] The present invention will now be described in detail. Furthermore, in the following description, depending on the structure represented by the chemical formula, there may be asymmetric carbon, resulting in mirror-image isomers and non-mirror-image isomers. In such cases, a single formula is used to represent such isomers. These isomers may be used individually or as a mixture of two or more.

[0018] [Chemical Amplification Positive Inhibitor Composition] [(A) Basic Polymer] The inhibitor composition of the present invention comprises a base polymer as component (A), which contains a polymer that decomposes under the action of acid and thus increases its solubility in alkaline developer.

[0019] The aforementioned polymer comprises repeating units (hereinafter also referred to as repeating unit A1) of an aromatic sulfonic acid anion having a polymerizable group and a triarylstrom cation having an iodine atom on the aromatic ring.

[0020] The anionic system of repeating unit A1 is represented by the following formula (A1-1). [Chemistry 11]

[0021] In formula (A1-1), n1 is 0 or 1. When n1 is 0, it is a benzene ring; when n1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n1 of 0 is preferred. n2 is 0, 1, 2, 3, or 4 when n1 is 0, and 0, 1, 2, 3, 4, 5, or 6 when n1 is 1. Considering the availability of raw materials, n2 of 0, 1, 2, 3, or 4 is preferred, with 0, 1, or 2 being even better.

[0022] In formula (A1-1), RA refers to a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atom and methyl group are preferred, with hydrogen atom being even more preferred.

[0023] In formula (A1-1), R1 represents a halogen atom, nitro group, cyano group, hydroxyl group, or may include a hydrocarbon group with 1 to 20 carbon atoms (heteroatomic), a hydrocarbon oxygen group with 1 to 20 carbon atoms (heteroatomic), or a hydrocarbon thio group with 1 to 20 carbon atoms (heteroatomic). The aforementioned halogen atom is preferably a fluorine atom, chlorine atom, bromine atom, or iodine atom, with fluorine or iodine atom being more preferred. Furthermore, the hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon thio group can be saturated or unsaturated, and 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, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 these. Among these, aryl is preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, the -CH2- group in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This results in the possible inclusion of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. Also, when n2 is 2 or more, each R1 can be the same or different.

[0024] Furthermore, when n2 is 2 or more, multiple R1 atoms can bond to each other and form a ring together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Also, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. Similarly, some of the -CH2- groups in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. The result is that the rings may 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, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), and haloalkyl groups.

[0025] In formula (A1-1), X1 represents a single bond, ether bond, ester bond, or amide bond. Among these, a single bond or ester bond is preferred, with a single bond being even more preferred.

[0026] Specific examples of aromatic sulfonic acid anions represented by formula (A1-1) are shown below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 12]

[0027] [Chemistry 13]

[0028] The repeating unit A1 is represented by the following formula (A1-2). [Chemistry 14]

[0029] In formula (A1-2), m1 is either 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m1=0 is preferred. m2 is either 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m2=0 is preferred. m3 is either 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m3=0 is preferred.

[0030] In formula (A1-2), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure, the less solvent-soluble it becomes, and there is a risk of precipitation in the inhibitor composition. Therefore, m4 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0031] In formula (A1-2), m5 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, m5 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m6 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m6 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better. m7 is 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m7 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0032] In formula (A1-2), m8 is 0, 1, or 2. Considering the availability of raw materials, m8 is preferably 0 or 1. m9 is 0, 1, or 2. Considering the availability of raw materials, m9 is preferably 0 or 1. m10 is 0, 1, or 2. Considering the availability of raw materials, m10 is preferably 0 or 1.

[0033] In formula (A1-2), m11 is 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m11 of 0 is preferred.

[0034] In formula (A1-2), m12 is 0, 1, 2, 3, or 4. Since the more iodine atoms in the cation structure, the less solvent-soluble it becomes and the more likely it is to precipitate in the inhibitor composition, m12 is preferably 0, 1, 2, or 3, with 0, 1, or 2 being even better.

[0035] In formula (A1-2), m13 is 0, 1, or 2. Considering the availability of raw materials, m13 is preferably 0 or 1. m14 is 0, 1, or 2. Considering the synthesis, m14 is preferably 0 or 1.

[0036] However, when m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6. When m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6. When m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0037] In formula (A1-2), RF1 to RF3 are each independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When m5 is 2 or more, each RF1 may be the same or different from the others; when m6 is 2 or more, each RF2 may be the same or different from the others; when m7 is 2 or more, each RF3 may be the same or different from the others.

[0038] In formula (A1-2), R2 to R5 are each independently a halogen atom other than iodine and fluorine atoms, a nitro group, a cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The hydrocarbon portion of the aforementioned hydrocarbon group, hydrocarbon oxy group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed as those exemplified by the hydrocarbon group represented by R1 in the description of formula (A1-1). Furthermore, one or all of the hydrogen atoms in the hydrocarbon group, hydroxyl group, and thiol group can be replaced by a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms. The -CH2- portion of the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, it can also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0039] Furthermore, when m8 is 2, the two R2 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms they are bonded to. When m9 is 2, the two R3 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms they are bonded to. When m10 is 2, the two R4 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms they are bonded to. When m13 is 2, the two R5 atoms can be the same or different, and they can also bond to each other and form a ring together with the carbon atoms they are bonded to. Specific examples of the rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norcamphene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned ring can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Similarly, some of the -CH2- groups in the aforementioned ring can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the ring 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, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0040] Furthermore, the aromatic rings of S+ in the strontium cation represented by formula (A1-2) can also bond to each other and form a ring together with S+. In this case, specific examples of the aforementioned ring structure can be listed in the following formulas. [Chemistry 15] In the formula, the dashed lines represent atomic bonds.

[0041] In formula (A1-2), LA and LB are each independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Of these, LA is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester or sulfonate bond being more preferred. LB is preferably a single bond, ether bond, or ester bond, with single bond being more preferred.

[0042] In formula (A1-2), XL represents a single bond, or may contain a heteroatom and be an extended hydrocarbon group with 1 to 40 carbon atoms. The aforementioned extended hydrocarbon group can be straight-chain, branched, or cyclic; specific examples include alkane dimethyl groups and divalent saturated cyclic hydrocarbon groups. The aforementioned heteroatoms can include oxygen atoms, nitrogen atoms, sulfur atoms, etc.

[0043] XL can also contain alkyl groups with 1 to 40 carbon atoms, preferably as shown below. Furthermore, in the following formula, * indicates a bond with LA and LB. [Chemistry 16]

[0044] [Chemistry 17]

[0045] [Chemistry 18]

[0046] Of these, XL-0~XL-3, XL-29~XL-34 and XL-47~XL-49 are better, and XL-0~XL-2, XL-29 and XL-47 are even better.

[0047] The strontium cation represented by formula (A1-2) should preferably be represented by the following formula (A1-2-1). [Chemistry 19] In the formula, m4~m10, m12~m14, RF1~RF3, R2~R5, LA, LB and XL are the same as those mentioned above.

[0048] The strontium cation represented by formula (A1-2-1) should preferably be represented by formula (A1-2-2). [Chemistry 20] In the formula, m4~m10, RF1~RF3 and R2~R5 are the same as those mentioned above.

[0049] Specific examples of strontium cations represented by formula (A1-2) are shown below, but are not limited to these. Furthermore, in the following formulas, Me is a methyl group. [Chemistry 21]

[0050] [Chemistry 22]

[0051] [Chemistry 23]

[0052] [Chemistry 24]

[0053] [Chemistry 25]

[0054] [Chemistry 26]

[0055] [Chemistry 27]

[0056] [Chemistry 28]

[0057] [Chemistry 29]

[0058] [Chemistry 30]

[0059] [Chemistry 31]

[0060] [Chemistry 32]

[0061] [Chemistry 33]

[0062] [Chemistry 34]

[0063] [Chemistry 35]

[0064] [Chemistry 36]

[0065] [Chemistry 37]

[0066] [Chemistry 38]

[0067] [Chemistry 39]

[0068] [Chemistry 40]

[0069] [Chemistry 41]

[0070] [Chemistry 42]

[0071] [Chemistry 43]

[0072] [Chemistry 44]

[0073] [Chemistry 45]

[0074] [Chemistry 46]

[0075] [Chemistry 47]

[0076] [Chemistry 48]

[0077] Specific examples of repeating unit A1 can be any combination of the aforementioned anions and cations.

[0078] Methods for synthesizing monomers from repeating unit A1 include those described in Japanese Patent Application Publication No. 2010-155824 and Japanese Patent No. 7067271. The aforementioned manufacturing method is only one example, and the manufacturing method of monomers from repeating unit A1 is not limited to these.

[0079] The structural features of repeating unit A1 can be exemplified by the onium salt composed of aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring and triarylstrom cations containing iodine atoms. The aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring will generate acid upon exposure; since the aromatic sulfonic acid is directly bonded to the polymer backbone, acid diffusion can be controlled to a high degree. Furthermore, the aromatic ring interacts with other copolymerizing units containing aromatic rings (π-π stacking interaction), exhibiting a regular and close arrangement, thus suppressing pattern collapse. On the other hand, the aromatic sulfonic acid anions with polymerizable groups directly bonded to the aromatic ring do not have very high organic solvent solubility. Furthermore, due to the presence of iodine atoms in the triarylstrom cation, solubility further decreases. However, by introducing multiple fluorine atoms onto the aromatic ring of the cation, organic solvent solubility can be ensured. Furthermore, the iodine and fluorine atoms in the cations possess electron attraction, thus lowering the energy level of the lowest empty molecular orbital (LUMO) in the leading-edge molecular orbital theory. This makes the cations more receptive to the generated secondary electrons, promoting cation decomposition and effectively generating acid, thereby achieving high sensitivity. In the exposed section, due to the efficient decomposition of cations, acid is fully generated, and the deprotection reaction of the protecting groups of the base polymer proceeds well. The aromatic sulfonic acid bonded to the backbone of the base polymer is readily soluble in the alkaline developer, thereby increasing the dissolution rate. On the other hand, in the unexposed section, the iodine atoms in the triarylsulfuron cation exhibit resistance to dissolution in the alkaline developer, reducing film loss in the unexposed section. Therefore, the dissolution contrast is improved. Through these synergistic effects, the chemical amplification positive resist composition of this invention exhibits high sensitivity and low acid diffusion, resulting in good resolution and LER, and enabling the formation of patterns resistant to pattern collapse, making it suitable for the formation of fine patterns.

[0080] The repeating unit A1 is suitable for use as a polymer-bonded photoacid generator.

[0081] The aforementioned polymer further comprises a repeating unit A2 having phenolic hydroxyl groups, represented by the formula (A2). [Chemistry 49]

[0082] In formula (A2), a1 is 0 or 1. a2 is 0, 1, or 2; 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 1, 2, or 3. When a2 is 0, a3 is preferably 0, 1, 2, or 3, and a4 is preferably 1, 2, or 3. When a2 is 1 or 2, a3 is preferably 0, 1, 2, 3, or 4, and a4 is preferably 1, 2, or 3.

[0083] In formula (A2), RA refers to hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups.

[0084] In formula (A2), R11 refers to a halogen atom, nitro group, cyano group, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon oxygen group and the saturated hydrocarbon carbonyl oxygen group, can be linear, branched, or cyclic. 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. 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 R11 can be the same or different from the others.

[0085] In formula (A2), A1 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. A portion of the -CH2- group may also be replaced by -O-. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic. Specific examples include 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, which are alkane diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, and other cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms; and groups obtained by combining these. When the aforementioned saturated hydrocarbon group contains an ether bond, when a1 in formula (A2) is 1, it can be inserted anywhere except between the carbon atom at the α-position and the carbon atom at the β-position for the ester oxygen atom. Furthermore, when a1 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 for this ether oxygen atom. Moreover, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solution can be obtained, which is ideal.

[0086] When a1 is 0 and A1 is a single bond, that is, when the aromatic ring is directly bonded to the polymer backbone (i.e., without a linker group (-C(=O)-O-A1-)), preferred examples of the repeating unit A2 include units from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. In particular, the repeating unit represented by the following formula (A2-1) is preferred. [Transformation 50] In the formula, RA and a4 are the same as those mentioned above.

[0087] When a1 is 0 and A1 is a single bond (i.e., does not have a linker base (-C(=O)-O-A1-)), preferred examples of the repeating unit A2 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 51]

[0088] [Chemistry 52]

[0089] [Chemistry 53]

[0090] [Chemistry 54]

[0091] [Chemistry 55]

[0092] When a1 is a series 1 (i.e., has -C(=O)-O-A1- as a linking base), a preferred example of the repeating unit A2 can be listed below, but is not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 56]

[0093] [Chemistry 57]

[0094] [Chem.58]

[0095] [Chemistry 59]

[0096] [Transformation 60]

[0097] [Chemistry 61]

[0098] The content of repeating unit A2 in the aforementioned polymer is preferably 30-90 mol%, and more preferably 40-85 mol%. However, if the polymer described later contains at least one of the repeating units represented by formula (A4) and formula (A5) that provides higher etch resistance, and this unit has a phenolic hydroxyl group as a substituent, then the ratio is also preferably within the aforementioned range. Repeating unit A2 can be used alone or in combination of two or more.

[0099] The aforementioned polymer provides the characteristic that the exposed portion, as a positive resist component, is soluble in alkaline developing solution. Therefore, it is preferable to include repeating units with acidic functional groups protected by acid-insecure groups, that is, repeating units that are protected by acid-insecure groups and are alkali-soluble due to the action of acid (hereinafter also referred to as repeating unit A3).

[0100] The best repeating unit A3 can be represented by the following formula (A3-1) (hereinafter also referred to as repeating unit A3-1). [Chemistry 62]

[0101] In formula (A3-1), b1 is 0 or 1. b2 is 0, 1, or 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 1, 2, or 3. b5 is 0 or 1. When b2 is 0, preferably b3 is 0, 1, 2, or 3, and b4 is 1, 2, or 3. When b2 is 1 or 2, preferably b3 is 0, 1, 2, 3, or 4, and b4 is 1, 2, or 3.

[0102] In formula (A3-1), RA refers to hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups.

[0103] In formula (A3-1), R12 is a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that may be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon oxygen group and the saturated hydrocarbon carbonyl oxygen group, can be linear, branched, or cyclic. 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. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. If b3 is 2 or more, each R12 can be the same or different.

[0104] In formula (A3-1), A2 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. A portion of the -CH2- group in this saturated hydrocarbon group can also be replaced by -O-. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic. Specific examples include 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, which are alkane diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, and other cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms; and groups obtained by combining these. When the aforementioned saturated hydrocarbon group contains an ether bond, b1 in formula (A3-1), when it is 1, can be inserted anywhere except between the carbon atom at the α-position and the carbon atom at the β-position for 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 for this ether oxygen atom. Moreover, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solution can be obtained, which is ideal.

[0105] In formula (A3-1), when b4 is 1, X is an acid-indestructible group. When b4 is 2 or 3, X is either a hydrogen atom or an acid-indestructible group, at least one of which is an acid-indestructible group. That is, the repeating unit A3-1 is either a phenolic hydroxyl group bonded to the aromatic ring that is protected by an acid-indestructible group, or a carboxyl group bonded to the aromatic ring that is protected by an acid-indestructible group. The aforementioned acid-indestructible groups have been widely used in a large number of known chemically amplified positive inhibitor compositions. As long as they provide an acidic group by means of acid removal, there are no particular limitations, and they can all be used.

[0106] The aforementioned acid-labile groups can be exemplified by, for example, tertiary saturated hydrocarbon groups. For obtaining the monomers used in polymerization by distillation, tertiary saturated hydrocarbon groups with 4 to 18 carbon atoms are preferred.

[0107] The saturated hydrocarbon groups bonded to the tertiary carbon atoms of the aforementioned tertiary saturated hydrocarbon groups should preferably have 1 to 15 carbon atoms. These saturated hydrocarbon groups with 1 to 15 carbon atoms can be linear, branched, or cyclic, and may also contain oxygen-containing functional groups such as ether bonds or carbonyl groups between the carbon-carbon bonds. Furthermore, the saturated hydrocarbon groups bonded to the tertiary carbon atoms can also bond to each other and form rings together with the tertiary carbon atoms to which they are bonded.

[0108] Saturated hydrocarbon groups bonded to the aforementioned tertiary carbon atoms can include methyl, ethyl, propyl, adamantyl, norcamphenyl, tetrahydrofuran-2-yl, 7-oxanorcamphenyl-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[4.4.0.12,5.17,10]dodecyl, 3-sideoxy-1-cyclohexyl, etc.

[0109] The aforementioned tertiary saturated hydrocarbon groups can be listed as tert-butyl, tert-pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1-adamantane-1-methylethyl, 1-methyl-1-(2-norbornenyl)ethyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 1-methyl-1-(7-oxanorbornen-2-yl)ethyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-propylcyclopentyl, 1-cyclopentylcyclopentyl, 1-cyclohexylcyclopentyl, 1-(2-tetrahydrofuranyl)cyclopentyl, 1-(7-oxanorbornen-2-yl)cyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 1-cyclopentylcyclohexyl, 1-cyclohexylcyclohexyl The following are included: 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.

[0110] Furthermore, the aforementioned acid-indestructible groups can be exemplified by groups represented by the following formula (A3-1-1). Groups represented by formula (A3-1-1) are commonly used as acid-indestructible groups, serving as a useful option for providing a more rectangular pattern at the interface between the pattern and the substrate. When X is a group represented by formula (A3-1-1), an acetal structure is formed. [Chemistry 63] In the formula, the dashed lines represent atomic bonds.

[0111] In formula (A3-1-1), RL1 is a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic.

[0112] RL1 can be appropriately selected based on the sensitivity of the group to acid decomposition. For example, if a design is intended to ensure high stability and decompose with strong acids, a group with a hydrogen atom or a carbon atom bonded to the acetal carbon is preferred, as it is a tertiary carbon atom. Examples of RL1 groups with a tertiary carbon atom bonded to the acetal carbon include tert-butyl, tert-pentyl, and 1-adamantyl, but are not limited to these. If a design is intended to use higher reactivity and is highly sensitive to pH changes, a straight-chain alkyl group is preferred. Also depending on the combination of acid generators and quenchers incorporated into the inhibitor composition, for RL2, in cases where a larger alkyl group is selected at the end and the solubility change due to decomposition is large, it is preferable that the carbon atom bonded to the acetal carbon in RL1 is a secondary carbon atom. Examples of RL1 groups with a secondary carbon atom bonded to the acetal carbon include isopropyl, tert-butyl, cyclopentyl, and cyclohexyl, but are not limited to these.

[0113] In formula (A3-1-1), 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. The -CH2- portion of this hydrocarbon group can also be replaced by heteroatoms such as oxygen or sulfur atoms, resulting in ether bonds, thioether bonds, etc. Specific examples of the aforementioned hydrocarbon group include saturated hydrocarbon groups with 1 to 30 carbon atoms and aryl groups with 6 to 30 carbon atoms. In particular, for fine pattern formation, it is preferable that RL2 is 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 acid deprotection reaction is water-soluble. Therefore, it will dissolve in the developer when forming positive patterns with an alkaline developer, thus suppressing residual defects in the exposed area.

[0114] Preferred examples of the base represented by formula (A3-1-1) are shown below, but are not limited to these. Furthermore, in the following formula, RL1 is the same as described above, and dashed lines represent atomic bonds. [Chemistry 64]

[0115] [Chemistry 65]

[0116] In addition to the aforementioned unstable acid groups, phenolic hydroxyl groups can also be replaced by -CH2COO- (tertiary saturated hydrocarbon group). In this case, the aforementioned tertiary saturated hydrocarbon group can be the same as the tertiary saturated hydrocarbon group used in the protection of the aforementioned phenolic hydroxyl group.

[0117] Furthermore, repeating unit A3 can also be represented by the following formula (A3-2) (hereinafter also referred to as repeating unit A3-2). Repeating unit A3-2 is a useful option for acid-containing unstable groups that provide good performance for linewidth variations under developing load, since the dissolution rate of the exposed section will increase. [Chemistry 66]

[0118] In equation (A3-2), c1 is 0, 1, or 2. c2 is 0, 1, or 2. c3 is 0, 1, 2, 3, 4, or 5. c4 is 0, 1, or 2.

[0119] In formula (A3-2), RA refers to hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups.

[0120] In formula (A3-2), R13 and R14 are each independently hydrocarbon groups with 1 to 10 carbon atoms, which may also contain heteroatoms. R13 and R14 can also bond to each other and form a ring together with the carbon atoms they are bonded to.

[0121] In formula (A3-2), R15 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.

[0122] In formula (A3-2), R16 is an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms.

[0123] In formula (A3-2), A3 is a single bond, an phenyl group, a naphthyl group, or *-C(=O)-O-A31-. A31 is an aliphatic alkyl group, an phenyl group, or a naphthyl group having 1 to 20 carbon atoms. This aliphatic alkyl group may also include at least one selected from hydroxyl, ether, ester, and lactone rings. * indicates an atomic bond with a carbon atom of the main chain.

[0124] Preferred examples of repeating unit A3-2 may be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 67]

[0125] [Chemistry 68]

[0126] The content of repeating unit A3 in all repeating units constituting the aforementioned polymer is preferably 5-95 mol%, and more preferably 20-80 mol%. Repeating unit A3 can be used alone or in combination of two or more types.

[0127] The aforementioned polymer may also include at least one of the repeating units represented by formula (A4) (hereinafter also referred to as repeating unit A4.), the repeating units represented by formula (A5) (hereinafter also referred to as repeating unit A5.), and the repeating units represented by formula (A6) (hereinafter also referred to as repeating unit A6.). [Chemistry 69]

[0128] In equations (A4) and (A5), d represents 0, 1, 2, 3, 4, 5, or 6. e represents 0, 1, 2, 3, or 4.

[0129] In formulas (A4) and (A5), R17 and R18 are each independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that may be substituted with a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxygen group, and saturated hydrocarbon carbonyl oxygen group can be linear, branched, or cyclic. When d is 2 or more, each R17 can be the same or different. When e is 2 or more, each R18 can be the same or different.

[0130] In formula (A6), f1 is 0 or 1. f2 is 0, 1 or 2; 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. f3 is 0, 1, 2, 3, 4 or 5. When f2 is 0, f3 should preferably be 0, 1, 2 or 3; when f2 is 1 or 2, f3 should preferably be 0, 1, 2, 3 or 4.

[0131] In formula (A6), RA represents hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups.

[0132] In formula (A6), R19 can be a halogen atom, nitro group, cyano group, saturated hydrocarbon group with 1-20 carbon atoms, saturated hydrocarbon oxy group with 1-20 carbon atoms, saturated hydrocarbon carbonyl oxy group with 2-20 carbon atoms, saturated hydrocarbon oxy hydrocarbon group with 2-20 carbon atoms, or saturated hydrocarbon thioalkyl hydrocarbon group with 2-20 carbon atoms. When f2 is 1 or 2, it can be a hydroxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, saturated hydrocarbon oxy hydrocarbon group, and saturated hydrocarbon thioalkyl hydrocarbon group can be linear, branched, or cyclic. When f3 is 2 or more, each R19 can be the same or different.

[0133] In formula (A6), A4 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms. A portion of the -CH2- group of the saturated alkyl group may also be replaced by -O-. The aforementioned saturated alkyl group may be linear, branched, or cyclic. Specific examples can be listed as those illustrated in the description of A1 in formula (A2).

[0134] When at least one of the repeating units A4 to A6 is used as a constituent unit of the aforementioned polymer, in addition to the etching resistance of the aromatic ring, the effect of improving etching resistance and EB irradiation resistance during pattern inspection can also be obtained by adding a ring structure to the main chain.

[0135] To improve etching resistance, the content of repeating units A4 to A6 should preferably be 5 mol% or more of all repeating units constituting the aforementioned polymer. Furthermore, the content of repeating units A4 to A6 should preferably be 25 mol% or less of all repeating units constituting the aforementioned polymer, and more preferably 20 mol% or less. Ideally, the amount introduced in the case of units without functional groups or with functional groups other than hydroxyl groups should be 25 mol% or less to avoid the risk of developing defects. Repeating units A4 to A6 can be used alone or in combination of two or more.

[0136] Of all the repeating units in the aforementioned polymer, the content of repeating units with an aromatic ring skeleton is preferably 65 mol% or more, more preferably 75 mol% or more, and even more preferably 85 mol% or more.

[0137] The aforementioned polymer may also include commonly used (meth)acrylate units protected by acid-labile groups, (meth)acrylate units with lactone structures, hydroxyl groups other than phenolic hydroxyl groups, or other close-knit groups. These repeating units allow for fine-tuning of the properties of the resist film; the polymer may also be omitted.

[0138] Examples of the aforementioned (meth)acrylate units with binding groups include repeating units represented by formula (A7) (hereinafter also referred to as repeating unit A7.), repeating units represented by formula (A8) (hereinafter also referred to as repeating unit A8.), and repeating units represented by formula (A9) (hereinafter also referred to as repeating unit A9.). These units do not exhibit acidity and can be used as auxiliary units to provide binding to the substrate and to adjust solubility. [Chemistry 70]

[0139] In formulas (A7) to (A9), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R21 is -O- or methylene. R22 is a hydrogen atom or a hydroxyl group. R23 is a saturated hydrocarbon group with 1 to 4 carbon atoms. g is 0, 1, 2, or 3.

[0140] When repeating units A7 to A9 are included, their content in the aforementioned polymer should preferably be 0 to 20 mol%, and more preferably 0 to 10 mol%. Repeating units B14 to B16 can be used alone or in combination of two or more.

[0141] The aforementioned polymer can be synthesized by copolymerizing monomers requiring protection using known methods, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but is preferably free radical polymerization or anionic polymerization. For such methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0142] Regarding the aforementioned polymers, a weight-average molecular weight (Mw) of 1000 to 50000 is preferred, and 2000 to 20000 is even more preferred. If Mw is 1000 or higher, as is known in the past, there is no risk of pattern dome formation leading to decreased resolution, or LER degradation. On the other hand, if Mw is 50000 or lower, there is no risk of LER degradation, especially when forming patterns with a linewidth of 100 nm or lower. Furthermore, in this invention, Mw is a polystyrene equivalent value obtained by gel permeation chromatography (GPC) using THF or DMF as a solvent.

[0143] For the aforementioned polymer, the molecular weight distribution (Mw / Mn) is 1.0~2.0, preferably 1.0~1.9, and more preferably a narrow dispersion of 1.0~1.8. In this narrow dispersion case, there will be no foreign matter on the pattern after development, or the pattern shape will be deteriorated.

[0144] Furthermore, as per the aforementioned basic polymer design, the dissolution rate of the alkaline developer should ideally be below 10 nm / min, even better than 7 nm / min, and further preferably below 5 nm / min. In advanced generations, when the substrate coating is a thin film region (below 100 nm), the impact on pattern loss during alkaline development becomes greater. When the polymer's alkaline dissolution rate exceeds 10 nm / min, the pattern will break down, making it impossible to form fine patterns. This is particularly noticeable when fabricating photomasks requiring defect-free results, where the development process tends to be more drastic. Furthermore, the dissolution rate of the basic polymer to the alkaline developer in this invention is calculated from the film loss after developing a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution at 23°C for 100 seconds on an 8-inch silicon wafer by spin-coating a polymer solution (polymer concentration: 16.7% by mass, solvent: propylene glycol monomethyl ether acetate (PGMEA)) onto the wafer and baking it at 100°C for 90 seconds to form a film with a thickness of 1000 nm.

[0145] (A) The base polymer may also include other polymers besides those mentioned above. Other polymers may be those known as base polymers used as inhibitor components. The content of other polymers is not particularly limited, as long as it does not impair the effect of the present invention.

[0146] [(B) Quenching agent] The chemically amplified positive resist composition of the present invention may, as needed, include a quencher as component (B). Furthermore, the term "quencher" in the present invention 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, thus inhibiting the effect of the acid generated within the resist film on the chromium-containing material even when using a substrate with its outermost surface made of a chromium-containing material.

[0147] The aforementioned quenching agents can be exemplified by conventional basic compounds. Conventional basic compounds can include primary, secondary, and tertiary 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, primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, especially amine compounds with hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds, or compounds with carbamate groups described in Japanese Patent No. 3790649, are preferred. Preferred alternatives include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, α-line 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 corrected.

[0148] Furthermore, the aforementioned quenchers include, for example, the strontium, monazine, and ammonium salts of α-unfluorinated carboxylic acids as described in Japanese Patent Application Publication No. 2008-158339. For α-fluorinated sulfonic acids, amide-imino acids, or methyl acids, deprotection of unstable acid groups is necessary. Salt exchange with α-unfluorinated onmium salts releases the α-unfluorinated carboxylic acid. Since the α-unfluorinated carboxylic acid hardly undergoes a deprotection reaction, it functions as a quencher.

[0149] Onium salts of carboxylic acids that are not fluorinated at the α-position, for example, can be represented by the following formula (B1). [Chemistry 71]

[0150] In formula (B1), R101 refers to hydrogen atoms or may also include hydrocarbon groups with 1 to 40 carbon atoms of heteroatoms, but excludes hydrogen atoms at the α-position of the carboxyl group that are replaced by fluorine atoms or fluoroalkyl groups.

[0151] R101 represents a hydrocarbon group that can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1-40 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; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, adamantyl, and adamantanemethyl; and vinyl, allyl, propenyl, butenyl, and hexenyl, etc. Alkenyl; cyclohexenyl and other cyclic unsaturated aliphatic hydrocarbon groups with 3 to 40 carbon atoms; 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 other aryl groups with 6 to 40 carbon atoms; benzyl, 1-phenylethyl, 2-phenylethyl and other aralkyl groups with 7 to 40 carbon atoms, etc.

[0152] Furthermore, one or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and one part of the aforementioned hydrocarbon group -CH2- can also be replaced by heteroatom groups containing oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, it can also include hydroxyl groups, cyano 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. Hydrocarbon groups containing heteroatoms can include heteroaryl groups such as thiophene; 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.

[0153] In formula (B1), MqA+ is an onium cation. The aforementioned onium cation is preferably a strontium cation, a ferrophosphate cation, or an ammonium cation, with strontium or ferrophosphate being more preferred. Specific examples of the aforementioned strontium cation may be listed in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those represented by formula (A2), but are not limited to these. Specific examples of the aforementioned ferrophosphate cation may be listed in paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259, but are not limited to these.

[0154] The anions of onium salts represented by formula (B1) can be listed below, but are not limited to these. [Chemistry 72]

[0155] [Chemistry 73]

[0156] [Chemistry 74]

[0157] The aforementioned quenching agent is also suitable for using strontium salts of carboxylic acids containing iodinated benzene rings, represented by the following formula (B2). [Chemistry 75]

[0158] In equation (B2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3. However, 1 ≦ s + t ≦ 5. u is 1, 2, or 3.

[0159] In formula (B2), R111 refers to 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 -N(R111A)-C(=O)-R111B or -N(R111A)-C(=O)-O-R111B. R111A is a hydrogen atom or a 1-6 carbon saturated hydrocarbon group. R111B 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 R111 can be the same or different from the others.

[0160] In formula (B2), L1 is a single bond or a (u+1) valent linkage with 1 to 20 carbon atoms, and may also include 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 may be linear, branched, or cyclic.

[0161] In formula (B2), R112, R113, and R114 are each independently a halogen atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 20 carbon atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, 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, sulfonic acid group, or a group containing strontium salt. The -CH2- portion of the aforementioned hydrocarbon groups can also be substituted by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Additionally, R112 and R113 can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

[0162] Specific examples of compounds represented by formula (B2) can be found in Japanese Patent Application Publication No. 2017-219836. Compounds represented by formula (B2) exhibit high absorption, high sensitization effect, and high acid diffusion control effect.

[0163] The aforementioned quenching agent may also be a nitrogen-containing carboxylate compound represented by the following formula (B3). [Chemistry 76]

[0164] In formula (B3), R121 to R124 are each independently a hydrogen atom, -L2-CO2-, or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom. R121 and R122, R122 and R123, or R123 and R124 may also bond to each other and form a ring together with the carbon atoms they are bonded to. L2 is a single bond or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom. R125 is a hydrogen atom or may contain a hydrocarbon group with 1 to 20 carbon atoms of a heteroatom.

[0165] In formula (B3), the ring Rr is a 2-6 carbon ring containing carbon and nitrogen atoms. Some or all of the hydrogen atoms bonded to the carbon atoms of this ring may be replaced by hydrocarbon groups with 1-20 carbon atoms, or by -L2-CO2-. Some of the carbon atoms of this ring may also be replaced by sulfur, oxygen, or nitrogen atoms. The aforementioned ring can be alicyclic or aromatic; 5- or 6-membered rings are preferred. Specific examples include pyridine rings, pyrrole rings, pyrrolidine rings, piperidine rings, pyrazole rings, imidazoline rings, pyrazine rings, pyrimidine rings, pyrazine rings, imidazoline rings, thiazole rings, thiazole rings, thiocyanate rings, thiazoline rings, triazole rings, etc.

[0166] The carboxylic acid salt represented by formula (B3) has at least one -L2-CO2- group. That is, at least one of R121 to R124 is -L2-CO2-, and / or at least one of the hydrogen atoms of the carbon atom bonded to the ring R is replaced by -L2-CO2-.

[0167] In formula (B3), MqB+ is a strontium cation, a monazine cation, or an ammonium cation, with a strontium cation being preferred. Specific examples of the aforementioned strontium cations may be cited in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those represented by formula (A2), but are not limited to these.

[0168] The anions of compounds represented by formula (B3) may be listed below, but are not limited to these. [Chemistry 77]

[0169] [Chemistry 78]

[0170] [Chemistry 79]

[0171] [Chemistry 80]

[0172] [Chemistry 81]

[0173] [Chemistry 82]

[0174] Furthermore, the aforementioned quenching agents may also be betaine-type compounds of weak acids. Specific examples are listed below, but are not limited to these. [Chemistry 83]

[0175] The aforementioned quenching agents can be further exemplified by the polymer-type quenching agent described in Japanese Patent Application Publication No. 2008-239918. This improves the rectangularity of the resist pattern by aligning it to the surface of the resist film. The polymer-type quenching agent also has the effect of preventing film loss and dome-shaped pattern when using a protective film for immersion exposure.

[0176] When the chemical amplification positive inhibitor composition of the present invention includes a 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. The aforementioned quencher can be used alone or in combination of two or more.

[0177] [(C) Organic solvent] The inhibitor composition of the present invention may also include an organic solvent as component (C). The aforementioned organic solvent is not particularly limited as long as it can dissolve each component. Examples of such organic solvents include, for example, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, 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), ethylene glycol monomethyl ether, etc. Ethers such as monomethyl ether of alcohol, monoethyl ether of propylene glycol, monoethyl ether of ethylene glycol, dimethyl ether of propylene glycol, and dimethyl ether of diethylene glycol; esters such as PGMEA, ethyl ether acetate of propylene glycol, ethyl lactate (EL), ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and tert-butyl ether acetate of propylene glycol; lactones such as γ-butyrolactone; and mixed solvents thereof. When using the unstable acid group of an acetal system, a high-boiling-point alcohol solvent, specifically diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, and 1,3-butanediol, can be added to accelerate the deprotection reaction of the acetal.

[0178] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixtures thereof are preferred.

[0179] When the chemical amplification positive inhibitor composition of the present invention contains (C) organic solvent, its content relative to 80 parts by mass of (A) 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.

[0180] [(D) Polymers containing fluorine atoms] The chemically amplified positive resist composition of this invention aims to achieve high contrast, suppress chemical flashes of acids under high-energy radiation, prevent the mixing of acids from the antistatic film during the coating of antistatic film material onto the resist film, and suppress unintended pattern degradation. It may also include a polymer containing fluorine atoms as component (D) containing 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.). The aforementioned polymer containing fluorine atoms also functions as a surfactant, thus preventing the re-adhesion of insoluble substances that may be generated during the development process to the substrate, and therefore also effective against development defects. [Chemistry 84]

[0181] In formulas (D1) to (D4), h refers to 1, 2, or 3. RB are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R201, R202, R204, and R205 are each independently a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. R203, R206, R207, and R208 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 R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, ether bonds or carbonyl groups may also be inserted between carbon-carbon bonds. Z1 refers to a (h+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (h+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms. * indicates an atomic bond with a carbon atom in the main chain.

[0182] R201, R202, R204, and R205 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.

[0183] R203, R206, R207, and R208 represent hydrocarbon groups with 1 to 15 carbon atoms, which can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 15 carbon atoms, alkenyl groups with 2 to 15 carbon atoms, and alkynyl groups with 2 to 15 carbon atoms, with alkyl groups with 1 to 15 carbon atoms being preferred. In addition to the aforementioned alkyl groups, other examples 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-pentadecayl. Furthermore, fluorinated hydrocarbon groups can be groups in which one or all of the hydrogen atoms of the carbon atoms bonded to the aforementioned hydrocarbon groups are replaced by fluorine atoms.

[0184] Z1 represents a (h+1) valence hydrocarbon group with 1 to 20 carbon atoms, which can be listed as an alkyl group with 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group with 3 to 20 carbon atoms, excluding groups with k hydrogen atoms. Furthermore, Z1 represents a (h+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms, which can be listed as a group in which at least one hydrogen atom of the aforementioned (h+1) valence hydrocarbon group is replaced by a fluorine atom.

[0185] Specific examples of repeating units D1 to D4 may be listed below, but are not limited to these. Furthermore, in the following formula, RB is the same as described above. [Chemistry 85]

[0186] [Chemistry 86]

[0187] [Chemistry 87]

[0188] Furthermore, the aforementioned fluorine-containing polymer is preferably a polymer that further comprises at least one of the repeating units represented by formula (D5) (hereinafter also referred to as repeating unit D5.) and the repeating units represented by formula (D6) (hereinafter also referred to as repeating unit D6.). [Chemistry 88]

[0189] In formulas (D5) and (D6), x represents 1, 2, or 3. y represents an integer satisfying 0 ≤ y ≤ 5 + 2z - x. z represents 0 or 1. RC represents either a hydrogen atom or a methyl group. R209 represents a hydrogen atom, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms may be inserted between carbon-carbon bonds. R210 represents a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms may be inserted between carbon-carbon bonds. R211 represents 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 the aforementioned saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. Z2 represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-. Z3 is a single bond, -O-, *-C(=O)-O-Z31-Z32-, or *-C(=O)-NH-Z31-Z32-. Z31 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms. Z32 is a single bond, ester bond, ether bond, or sulfonamide bond. * is an atomic bond with a carbon atom in the main chain.

[0190] R209 and R210 represent hydrocarbon groups with 1 to 5 carbon atoms, including alkyl, alkenyl, and ynyl groups, with alkyl being preferred. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, and n-pentyl. Furthermore, heteroatoms such as oxygen, sulfur, and nitrogen atoms can be inserted between the carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0191] In formula (D5), -OR209 is preferably a hydrophilic group. In this case, R209 is preferably a hydrogen atom, an alkyl group with 1 to 5 carbon atoms with an oxygen atom inserted between carbon-carbon bonds, etc.

[0192] R211 represents a saturated hydrocarbon group with 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom. It can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom.

[0193] 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 of the antistatic film. Also, if RC is methyl, it becomes a rigid polymer with a higher glass transition temperature (Tg), thus inhibiting acid diffusion. Consequently, the historical stability of the resist film is improved, and the resolution and pattern shape do not deteriorate.

[0194] Z3 represents a saturated extended hydrocarbon group with 1 to 10 carbon atoms, which 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, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, and 1,1-dimethylethane-1,2-diyl.

[0195] Repeating unit D5 may include, but is not limited to, those shown below. Furthermore, in the following formula, RC is the same as described above. [Chemistry 89]

[0196] [Chemistry 90]

[0197] Repeating unit D6 may include, but is not limited to, those shown below. Furthermore, in the following formula, RC is the same as described above. [Chemistry 91]

[0198] [Chemistry 92]

[0199] [Chemistry 93]

[0200] [Chemistry 94]

[0201] The content of repeating units D1 to D4 in the aforementioned polymer containing fluorine atoms is preferably 15 to 95 mol%, and more preferably 20 to 85 mol%. The content of repeating units D5 and / or D6 in the aforementioned polymer containing fluorine atoms is preferably 5 to 85 mol%, and more preferably 15 to 80 mol%. Repeating units D1 to D6 can be used alone or in combination of two or more.

[0202] (D) The polymer containing fluorine atoms may also contain other repeating units besides the aforementioned repeating units. Such repeating units can be listed in paragraphs

[0046] to

[0078] of Japanese Patent Application Publication No. 2014-177407. (D) When the polymer containing fluorine atoms contains other repeating units, their content in all repeating units of the aforementioned polymer containing fluorine atoms should preferably be 50 mol% or less.

[0203] (D) Polymers containing fluorine atoms can be synthesized by copolymerizing monomers requiring protection using known methods, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but free radical polymerization or anionic polymerization is preferred. For such methods, please refer to Japanese Patent Application Publication No. 2004-115630.

[0204] (D) For polymers containing fluorine atoms, a Mw of 2000-50000 is preferred, and 3000-20000 is even better. If Mw is above 2000, acid will not diffuse, resolution will not deteriorate, and historical stability will not be compromised. If Mw is below 50000, the solubility in solvents is sufficient, and coating defects will not occur. Furthermore, for polymers containing fluorine atoms in (D), an Mw / Mn ratio of 1.0-2.2 is preferred, and 1.0-1.7 is even better.

[0205] When the chemical amplification positive inhibitor composition of the present invention contains (D) a polymer containing fluorine atoms, its content relative to 80 parts by mass of the (A) base polymer is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass. The (D) polymer containing fluorine atoms can be used alone or in combination of two or more.

[0206] [(E) Photoacid Generator] The chemical amplification positive inhibitor composition of the present invention may also include a photoacid generator as component (E). The aforementioned photoacid generator is not particularly limited to compounds that produce acid when irradiated with high-energy rays. Preferred photoacid generators include strontium salts, ferrous salts, sulfadiazine, N-sulfonoxyimide, and oxime-O-sulfonate acid generators.

[0207] Specific examples of the aforementioned photoacid generators include nonafluorobutyrate, the partially fluorinated sulfonates described in paragraphs

[0247] to

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

[0261] to

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

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, and the partially fluorinated sulfonates described in paragraphs

[0080] to

[0081] of Japanese Patent Application Publication No. 2010-215608. Among the aforementioned specific examples, the photoacid generators of the aromatic hydrocarbon sulfonate type or the alkane sulfonate type produce an acid of appropriate strength for deprotecting the acid unstable group of the repeating unit A3, which is ideal.

[0208] Such photoacid generators are preferably salt compounds containing the anions shown below. [Chemistry 95]

[0209] [Chemistry 96]

[0210] [Chemistry 97]

[0211] [Chem. 98]

[0212] [Chemistry 99]

[0213] [Chemistry 100]

[0214] [Chemistry 101]

[0215] [Chemistry 102]

[0216] [Chemistry 103]

[0217] [Chemistry 104]

[0218] [Chemistry 105]

[0219] [Chemistry 106]

[0220] [Chemistry 107]

[0221] [Chemistry 108]

[0222] [Chemistry 109]

[0223] [Chemical 110]

[0224] [Chemistry 111]

[0225] [Chemistry 112]

[0226] [Chemistry 113]

[0227] [Chemistry 114]

[0228] [Chemistry 115]

[0229] [Chemistry 116]

[0230] [Chemistry 117]

[0231] [Chemistry 118]

[0232] [Chemistry 119]

[0233] [Chemistry 120]

[0234] [Chemistry 121]

[0235] [Chemistry 122]

[0236] [Chemistry 123]

[0237] [Chemistry 124]

[0238] [Chemistry 125]

[0239] [Chemistry 126]

[0240] [Chemistry 127]

[0241] [Chemistry 128]

[0242] [Chemistry 129]

[0243] [Chemistry 130]

[0244] [Chemistry 131]

[0245] [Chemistry 132]

[0246] [Chemistry 133]

[0247] [Chemistry 134]

[0248] [Chemistry 135]

[0249] [Chemistry 136]

[0250] [Chemistry 137]

[0251] [Chemistry 138]

[0252] [Chemistry 139]

[0253] [Chemistry 140]

[0254] [Chemistry 141]

[0255] [Chemistry 142]

[0256] [Chemistry 143]

[0257] [Chemistry 144]

[0258] [Chemistry 145]

[0259] [Chemistry 146]

[0260] [Chemistry 147]

[0261] [Chemistry 148]

[0262] [Chemistry 149]

[0263] [Chemistry 150]

[0264] [Chemistry 151]

[0265] [Chemistry 152]

[0266] [Chemistry 153]

[0267] [Chemistry 154]

[0268] [Chemistry 155]

[0269] [Chemistry 156]

[0270] [Chemistry 157]

[0271] [Chemistry 158]

[0272] [Chemistry 159]

[0273] [Chemistry 160]

[0274] [Chemistry 161]

[0275] [Chemistry 162]

[0276] [Chemistry 163]

[0277] [Chemistry 164]

[0278] [Chemistry 165]

[0279] [Chemistry 166]

[0280] [Chemistry 167]

[0281] [Chemistry 168]

[0282] [Chemistry 169]

[0283] [Chemistry 170]

[0284] [Chemistry 171]

[0285] [Chemistry 172]

[0286] [Chemistry 173]

[0287] [Chemistry 174]

[0288] [Chemistry 175]

[0289] [Chemistry 176]

[0290] [Chemistry 177]

[0291] [Chemistry 178]

[0292] [Chemistry 179]

[0293] [Chemistry 180]

[0294] [Chemistry 181]

[0295] [Chemistry 182]

[0296] [Chemistry 183]

[0297] [Chemistry 184]

[0298] [Chemistry 185]

[0299] [Chemistry 186]

[0300] [Chemistry 187]

[0301] [Chem.188]

[0302] [Chemistry 189]

[0303] [Chemistry 190]

[0304] [Chemistry 191]

[0305] [Chemistry 192]

[0306] [Chemistry 193]

[0307] [Chemistry 194]

[0308] [Chemistry 195]

[0309] [Chemistry 196]

[0310] [Chemistry 197]

[0311] [Chemistry 198]

[0312] [Chemistry 199]

[0313] [Chemistry 200]

[0314] [Chemical Engineering 201]

[0315] [Chemical Engineering 202]

[0316] [Chemical Engineering 203]

[0317] [Chemical 204]

[0318] [Chemical Engineering 205]

[0319] [Chemical Engineering 206]

[0320] [Chemical 207]

[0321] [Chemical Engineering 208]

[0322] [Chemical Engineering 209]

[0323] [Chemical 210]

[0324] [Chemistry 211]

[0325] [Chemistry 212]

[0326] [Chemistry 213]

[0327] [Chemistry 214]

[0328] [Chemical 215]

[0329] [Chemistry 216]

[0330] [Chemistry 217]

[0331] [Chemistry 218]

[0332] [Chemistry 219]

[0333] [Chem.220]

[0334] [Chemistry 221]

[0335] [Chemistry 222]

[0336] [Chemistry 223]

[0337] [Chemistry 224]

[0338] [Chemistry 225]

[0339] [Chemistry 226]

[0340] [Chemistry 227]

[0341] [Chemistry 228]

[0342] [Chemistry 229]

[0343] [Chemistry 230]

[0344] [Chemistry 231]

[0345] [Chemistry 232]

[0346] [Chemistry 233]

[0347] [Chemistry 234]

[0348] [Chemistry 235]

[0349] [Chemistry 236]

[0350] [Chemistry 237]

[0351] [Chemistry 238]

[0352] [Chemistry 239]

[0353] [Chemistry 240]

[0354] [Chemistry 241]

[0355] [Chemistry 242]

[0356] [Chemistry 243]

[0357] [Chemistry 244]

[0358] [Chemistry 245]

[0359] [Chemistry 246]

[0360] [Chemistry 247]

[0361] [Chemistry 248]

[0362] [Chemistry 249]

[0363] [Chemistry 250]

[0364] [Chemistry 251]

[0365] [Chemistry 252]

[0366] [Chemistry 253]

[0367] [Chemistry 254]

[0368] [Chemistry 255]

[0369] [Chemistry 256]

[0370] [Chemistry 257]

[0371] [Chemistry 258]

[0372] [Chemistry 259]

[0373] [Chemistry 260]

[0374] [Chemistry 261]

[0375] [Chemistry 262]

[0376] [Chemistry 263]

[0377] [Chemistry 264]

[0378] [Chemistry 265]

[0379] [Chemistry 266]

[0380] [Chemistry 267]

[0381] [Chemistry 268]

[0382] [Chemistry 269]

[0383] [Chemistry 270]

[0384] [Chemistry 271]

[0385] [Chemistry 272]

[0386] [Chemistry 273]

[0387] [Chemistry 274]

[0388] [Chemistry 275]

[0389] [Chemistry 276]

[0390] [Chemistry 277]

[0391] [Chemistry 278]

[0392] [Chemistry 279]

[0393] [Chemistry 280]

[0394] [Chemistry 281]

[0395] [Chemistry 282]

[0396] [Chemistry 283]

[0397] [Chemistry 284]

[0398] [Chemistry 285]

[0399] [Chemistry 286]

[0400] [Chemistry 287]

[0401] [Chemistry 288]

[0402] [Chemistry 289]

[0403] [Chemistry 290]

[0404] [Chemistry 291]

[0405] [Chemistry 292]

[0406] [Chemistry 293]

[0407] [Chemistry 294]

[0408] [Chemistry 295]

[0409] [Chemistry 296]

[0410] [Chemistry 297]

[0411] [Chemistry 298]

[0412] [Chemistry 299]

[0413] [Chemical 300]

[0414] [Chemical Engineering 301]

[0415] [Chemical 302]

[0416] [Chemical 303]

[0417] [Chemical 304]

[0418] [Chemical 305]

[0419] [Chemical 306]

[0420] [Chemical 307]

[0421] [Chemical 308]

[0422] [Chemical 309]

[0423] [Chemical 310]

[0424] [Chemistry 311]

[0425] [Chemistry 312]

[0426] [Chemistry 313]

[0427] [Chemical 314]

[0428] [Chemical 315]

[0429] [Chemistry 316]

[0430] [Chemistry 317]

[0431] [Chemistry 318]

[0432] [Chemistry 319]

[0433] [Chem.320]

[0434] [Chemistry 321]

[0435] [Chemistry 322]

[0436] [Chemistry 323]

[0437] [Chemistry 324]

[0438] [Chemistry 325]

[0439] [Chemistry 326]

[0440] [Chemistry 327]

[0441] [Chemistry 328]

[0442] [Chemistry 329]

[0443] [Chemistry 330]

[0444] [Chemistry 331]

[0445] [Chemistry 332]

[0446] [Chemistry 333]

[0447] [Chemistry 334]

[0448] [Chemistry 335]

[0449] [Chemistry 336]

[0450] Furthermore, the aforementioned photoacid generator should preferably be a salt compound containing an anion represented by the following formula (E1). [Chemistry 337]

[0451] In equation (E1), m1 is 0 or 1. p is 1, 2 or 3. q is 1, 2, 3, 4 or 5. r is 0, 1, 2 or 3. However, 1 ≦ q + r ≦ 5.

[0452] In formula (E1), L11 refers to single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds or carbamate bonds.

[0453] In formula (E1), L12 refers to ether bonds, ester bonds, sulfonate bonds, carbonate bonds or carbamate bonds.

[0454] In formula (E1), LC is a single bond or an extended hydrocarbon group with 1 to 20 carbon atoms when p is 1, and a (p+1) valence hydrocarbon group with 1 to 20 carbon atoms when p is 2 or 3. The extended hydrocarbon group and the (p+1) valence hydrocarbon group may also include 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 carboxyl group.

[0455] LC represents a hydrocarbon group with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkane diyl groups with 1 to 20 carbon atoms, such as methane-diyl, 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 cyclopentane-diyl, cyclohexane-diyl, norcamphene-diyl, and adamantane-diyl; 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 phenylene and naphthyl; and groups obtained by combining these. Furthermore, LC represents (p+1) valence hydrocarbon groups with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be derived by further eliminating one or two hydrogen atoms from the aforementioned examples of hydrocarbon groups with 1 to 20 carbon atoms.

[0456] In formula (E1), Rf1 and Rf2 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom, with at least one fluorine atom or a trifluoromethyl atom.

[0457] In formula (E1), 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.

[0458] R301, R301A, R301B, and R301C represent saturated hydrocarbon groups with 1 to 6 carbon atoms, which can be linear, 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 portion of the saturated hydrocarbon oxygen 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 portion of the saturated hydrocarbon carbonyl oxygen 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.

[0459] 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.

[0460] In formula (E1), 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 also 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.

[0461] R302 represents an extended hydrocarbon group with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be listed as those exemplified by the extended hydrocarbon groups with 1 to 20 carbon atoms represented by LC.

[0462] R302 represents specific examples of aryl groups with 6 to 20 carbon atoms, such as phenyl, naphthyl, phenanthrenediyl, and anthracenediyl. The saturated hydrocarbon group with 1 to 20 carbon atoms and the hydrocarbon group with 1 to 20 carbon atoms that serve as substituents for 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, decadecyl, heptadecyl, octadecyl, nonadecanyl, and icosyl; 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 as substituents include arylphenyl, arylnaphthyl, phenanthrenediyl, anthracenediyl, etc.

[0463] The anion represented by formula (E1) should preferably be represented by formula (E2). [Chemistry 338]

[0464] In formula (E2), p, q, r, L11, LC, and R301 are the same as described above. m2 is 1, 2, 3, or 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. Furthermore, when m2 is 2, 3, or 4, each R302A can be the same or different from the others.

[0465] Specific examples of anions represented by formula (E1) are shown below, but are not limited to these. [Chemistry 339]

[0466] [Transformation 340]

[0467] [Chemistry 341]

[0468] [Chemistry 342]

[0469] [Chemistry 343]

[0470] [Chemistry 344]

[0471] [Chemistry 345]

[0472] [Chemistry 346]

[0473] [Chemistry 347]

[0474] [Chemistry 348]

[0475] [Chemistry 349]

[0476] [Chemical 350]

[0477] [Chemistry 351]

[0478] [Chemistry 352]

[0479] [Chemistry 353]

[0480] [Chemistry 354]

[0481] [Chemistry 355]

[0482] [Chemistry 356]

[0483] [Chemistry 357]

[0484] [Chemistry 358]

[0485] [Chemistry 359]

[0486] [Hua360]

[0487] [Chemistry 361]

[0488] [Chemistry 362]

[0489] [Chem.363]

[0490] [Chemical formula 364]

[0491] [Chemical formula 365]

[0492] [Chemical formula 366]

[0493] [Chemical formula 367]

[0494] [Chemical formula 368]

[0495] [Chemical formula 369]

[0496] [Chemical formula 370]

[0497] [Chemical formula 371]

[0498] [Chemical formula 372]

[0499] [Chemical formula 373]

[0500] [Chemical formula 374]

[0501] [Chemical formula 375]

[0502] (E) In the photoacid generating agent, the cation paired with the aforementioned anion is preferably a strontium cation or a ferrous cation. Specific examples of the aforementioned strontium cation may be cited in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those expressed by formula (A2), but are not limited to these. Specific examples of the aforementioned ferrous cation may be cited in paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259, but are not limited to these.

[0503] For the acid generated by the aforementioned photoacid generator, a pKa of -2.0 or higher is preferred, and -1.0 or higher is even better. Furthermore, an upper limit of 2.0 for the pKa is preferable. The pKa value was calculated using the pKa DB function in ACD / Chemsketch ver: 9.04, software developed by Advanced Chemistry Development, Inc.

[0504] When the chemical amplification positive resist composition of the present invention includes an (E) photoacid generator, its content relative to 80 parts by weight of the aforementioned base polymer is preferably 1 to 10 parts by weight, and more preferably 1 to 5 parts by weight. By including the (E) photoacid generator, the amount of acid generated in the exposed portion and the solubility resistance of the unexposed portion can be appropriately adjusted. The (E) photoacid generator can be used alone or in combination of two or more.

[0505] When the chemically amplified positive resist composition of the present invention simultaneously contains (E) a photoacid generator and (B) a quencher, the content ratio of the photoacid generator to the quencher (photoacid generator / quencher) is preferably such that the mass ratio is less than 3, 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 aforementioned chemically amplified positive resist composition is within the aforementioned range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0506] (F) Surfactants To improve the coatability of the substrate, the chemically amplified positive resist composition of the present invention may also include conventional surfactants as component (F). The aforementioned surfactants are widely known, as described in International Patent Application 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 may be referenced and selected from these publications.

[0507] When the chemical amplification positive inhibitor composition of the present invention includes surfactant (F), its content relative to 80 parts by mass of the base polymer (A) is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and preferably 0.01 parts by mass or more. Surfactant (F) can be used alone or in combination of two or more.

[0508] [Resistant Pattern Formation Method] The resist pattern forming method of the present invention includes the steps of forming a resist film on a substrate using the aforementioned chemically amplified positive resist composition, exposing the aforementioned resist film using high-energy rays, and developing the aforementioned patterned resist film using an alkaline developer to obtain the resist pattern.

[0509] The aforementioned substrate can be, for example, a substrate used for integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate used for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, etc.). The aforementioned chemically amplified positive resist composition is coated onto the substrate using a spin-coating or similar method to achieve a film thickness of 0.03~2 μm. The substrate is then placed on a heating plate and pre-baked, preferably at 60~150°C for 1~20 minutes, more preferably at 80~140°C for 1~10 minutes, to form a resist film.

[0510] Then, 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, X-rays, gamma rays, and synchrotron radiation.

[0511] When using ultraviolet light, far-ultraviolet light, excimer laser light, EUV, X-rays, gamma rays, or synchrotron radiation for high-energy lithography, a mask is used to form the pattern of the target, and irradiation is carried out at an exposure dose preferably of 1-300 mJ / cm², more preferably 10-200 mJ / cm². When using EB lithography for high-energy lithography, direct drawing is carried out at an exposure dose preferably of 1-300 μC / cm², more preferably 10-200 μC / cm². Furthermore, the chemical amplification positive resist composition of the present invention is particularly useful in EUV or EB lithography.

[0512] In addition to the usual exposure method, exposure can also be achieved by wetting the mask and resist film with a liquid between them, depending on the circumstances. In this case, a water-insoluble protective film can also be used.

[0513] Then, on a heated plate, expose and bake (PEB) at 60~150℃ for 1~20 minutes, more preferably at 80~140℃ for 1~10 minutes.

[0514] Subsequently, a developing solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of preferably 0.1-5% by mass, more preferably 2-3% by mass, is used to develop the substrate using conventional methods such as dip, immersion, or spraying for 0.1-3 minutes, preferably 0.5-2 minutes, thereby forming the target pattern on the substrate.

[0515] The chemically amplified positive resist composition of this invention is particularly useful when high etch resistance is required, and when the pattern linewidth variation remains small even with prolonged exposure time up to PEB, and the LER remains low. Furthermore, the resist composition of this invention is especially useful on substrates made of materials where it is difficult to achieve a tight adherence to the resist pattern, thus easily leading to pattern peeling and pattern breakage. Examples of such substrates include those 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 this invention is particularly useful in pattern formation using a blank photomask as a substrate. [Example]

[0516] The present invention will be specifically described below by illustrating synthesis examples, embodiments, and comparative examples. The present invention is not limited to the embodiments described below. Furthermore, the copolymer composition ratio is a molar ratio, and Mw is a polystyrene conversion value obtained using GPC. The apparatus used is as follows. •IR: Nicolet 6700, manufactured by Thermo Fisher Scientific ･1H-NMR: ECA-500 manufactured by Nippon Electronics Co., Ltd. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0517] [1] Synthesis of onium salt type monomers [Synthetic Example 1-1] Synthesis of Onium Salt Monomer A1-1 [Chemistry 376]

[0518] Under nitrogen atmosphere, an aqueous solution of raw material SM-1 (1046.2 g, equivalent to 47.1 g of pure substance), raw material SM-2 (21.6 g), and dichloromethane (300 g) were added, and the mixture was stirred at room temperature for 30 minutes. The organic layer was separated, washed with water, and then concentrated under reduced pressure to obtain onium salt monomer A1-1 as an oily substance (yield 56.7 g, 93% yield).

[0519] The IR spectrum data and TOF-MS results of the onium salt type monomer A1-1 are shown below. Furthermore, the nuclear magnetic resonance spectrum (1H-NMR / DMSO-d6) results are shown in Figure 1. IR(D-ATR):ν=3436, 3060, 1706, 1599, 1560, 1495, 1443, 1387, 1294, 1200, 1134, 1123, 1055, 1033, 1009, 999, 912, 864, 844, 733, 719, 699, 675, 581, 555, 539, 508, 491 cm-1. MALDI TOF-MS: POSITIVE M+461 (equivalent to C18H10F4IS+) NEGATIVE M-183 (equivalent to C8H7O3S-)

[0520] [2] Polymer Synthesis [Synthetic Example 2-1] Synthesis of Polymer P-1 Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking monomer A1-1 (19.2 g), monomer A2-1 (50.1 g), monomer A3-1-1 (30.7 g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals Co., Ltd.) 6.86 g, and MEK 139 g in a flask. In another flask under nitrogen atmosphere, MEK 46 g was taken and heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of hexane under vigorous stirring. The precipitated polymer was filtered. The obtained polymer was washed twice with 600 g of hexane and then vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 97.1 g, 97% yield). The Mw of polymer P-1 is 9700, and the Mw / Mn ratio is 1.62. Furthermore, the Mw value is a polystyrene conversion value obtained using GPC with DMF as the solvent. [Chemistry 377]

[0521] [Synthetic Examples 2-2~2-60, Comparative Synthetic Examples 1-1~1-38] Synthesis of polymers P-2~P-60 and comparative polymers CP-1~CP-38 By changing the types and blending ratios of the monomers, polymers P-2 to P-60 shown in Tables 1 and 2, and comparative polymers CP-1 to CP-38 shown in Table 3, were synthesized using the same method as in Synthesis Example 2-1. In Tables 1-3, the induction ratios are shown as molar ratios.

[0522] [Table 1]

[0523] [Table 2]

[0524] [Table 3]

[0525] The monomers used in the synthesis of polymers are as follows. [Chemistry 378]

[0526] [Chemistry 379]

[0527] [Chemistry 380]

[0528] [Chemistry 381]

[0529] [Chemistry 382]

[0530] [Chemistry 383]

[0531] [Chem. 384]

[0532] The dissolution rate of the aforementioned polymers in alkaline developer was calculated by spin-coating a polymer solution (polymer concentration: 16.7% by mass, solvent: PGME) onto an 8-inch silicon wafer, baking it at 100°C for 90 seconds to form a 1000 nm thick film, developing it with a 2.38% by mass TMAH aqueous solution at 23°C for 100 seconds, and measuring the film loss. The results showed that the dissolution rate of polymers P-1 to P-60 was less than 10 nm / min. Furthermore, the dissolution rate of polymers CP-1 to CP-38 was also less than 10 nm / min.

[0533] [Synthetic Examples 3-1~3-16] Synthesis of Polymers AP-1~AP-16 By changing the raw material compounds used, the polymers AP-1 to AP-16 shown below were synthesized using the same method as in Synthesis Example 1-1. [Chem. 385]

[0534] [Chemistry 386]

[0535] [Chemistry 387]

[0536] [Chem.388]

[0537] The dissolution rate of polymers AP-1 to AP-16 is below 10 nm / min.

[0538] [2] Preparation of chemically amplified positive inhibitor composition [Examples 1-1 to 1-100, Comparative Examples 1-1 to 1-60] The components were dissolved in an organic solvent using the compositions shown in Tables 4-8 below. The resulting solutions were filtered through a 5nm nylon filter and a sub-1nm UPE filter to prepare a chemically amplified positive inhibitor composition. The aforementioned organic solvents were 920 parts by mass of PGMEA, 1850 parts by mass of EL, or a mixture of 1850 parts by mass of diacetone alcohol and 1850 parts by mass of PGME.

[0539] [Table 4]

[0540] [Table 5]

[0541] [Table 6]

[0542] [Table 7]

[0543] [Table 8]

[0544] Furthermore, the structures of quenchers Q-1 to Q-5, photoacid generators PAG-1 to PAG-6, and polymers FP-1 to FP-5 in Tables 4 to 8 are as follows. [Chemistry 389]

[0545] [Chemistry 390]

[0546] [Chemistry 391]

[0547] [3] EB Microfilm Review [Examples 2-1 to 2-100, Comparative Examples 2-1 to 2-60] Various chemically amplified positive resist compositions (R-1~R-100, CR-1~CR-60) were spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using ACT-M (manufactured by Tokyo Power Technology Co., Ltd.). The mask was then pre-baked at 110°C for 600 seconds on a heated plate to produce a resist film with a thickness of 80 nm. 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 points within the surface of the blank substrate, excluding the outer edge portion extending 10 mm inwards, and the average film thickness and thickness range were calculated.

[0548] Then, an electron beam exposure device (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., with an accelerating voltage of 50kV) was used for exposure, and PEB was performed at 110°C for 600 seconds. The image was then developed with a 2.38% by mass TMAH aqueous solution to obtain a positive pattern.

[0549] The obtained resist patterns were evaluated as follows. The prepared patterned blank mask was observed using an overhead SEM (scanning electron microscope). The optimal exposure (μC / cm²) was defined as the exposure for resolving 1:1 lines and spacing (LS) at 200 nm using a 1:1 ratio. The smallest size among the exposures for resolving 1:1 LS at 200 nm was defined as the resolution (limiting resolution). The LER (Lead Reduction) of the 200 nm LS was measured using SEM. For the limiting resolution of isolation spacing (IS), the smallest size among the exposures for resolving 9:1 lines and spacing (LS) at 9:1 ratio at 200 nm was defined as the limiting resolution. The pattern shape was visually determined to be rectangular. The results are shown in Tables 9-13.

[0550] [Table 9]

[0551] [Table 10]

[0552] [Table 11]

[0553] [Table 12]

[0554] [Table 13]

[0555] [4] Evaluation of etching resistance [Examples 3-1 to 3-6, Comparative Examples 3-1 to 3-4] Various chemically amplified positive resist compositions (R-2, R-7~R-11, CR-2, CR-7~CR-9) were spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using an ACT-M spin-coating machine. The mask was then pre-baked at 110°C for 600 seconds on a heated plate to create a resist film with a thickness of 120 nm. The film thickness of the obtained resist film was measured using an optical measuring instrument, Nanospec (Nanometrics). Measurements were taken at 81 points within the surface of the blank substrate, excluding the outer edge portion extending 10 mm inwards, and the average film thickness and thickness range were calculated. The coated substrate was then dry-etched using a UNAXIS G4 dry etching apparatus under the following conditions, and the film loss rate (A / sec) derived from the etched residual film was calculated. The results are shown in Table 11.

[0556] RF1(RIE): Pulse 700V RF2(ICP):CW 400W Pressure: 6mTorr Cl2: 185 sccm O2:55sccm He: 9.25 sccm Etching time: 75 seconds

[0557] [Table 14]

[0558] The chemically amplified positive resist compositions (R-1 to R-100) of this invention all exhibit good resolution, LER, and pattern rectangularity. On the other hand, the resist compositions of the comparative examples (CR-1 to CR-60) show insufficient optimization of acid diffusion, resulting in deterioration in resolution, LER, and pattern rectangularity. Furthermore, in the dry etching evaluation using R-2, R-7 to R-11, the etching resistance is better compared to CR-2, CR-7 to CR-9, demonstrating that the presence of the (A1) framework of this invention in the polymer is effective in masking systems.

[0559] The resist patterning method using the chemically amplified positive resist composition of the present invention is useful in the manufacture of semiconductor devices, especially in the processing of transmissive and reflective blank photomasks.

Claims

1. A chemically amplified positive inhibitor composition, comprising: a base polymer (A), which is a polymer whose solubility in an alkaline aqueous solution increases due to the action of an acid, comprising: a repeating unit consisting of an aromatic sulfonic acid anion represented by formula (A1-1) and a strontium cation represented by formula (A1-2), and a repeating unit represented by formula (A2), and a polymer whose solubility in an alkaline aqueous solution increases due to the action of an acid, wherein n1 is 0 or 1, n2 is 0, 1, 2, 3 or 4 when n1 is 0, and 0, 1, 2, 3, 4, 5 or 6 when n1 is 1, and RA is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R1 can be a halogen atom, nitro group, cyano group, hydroxyl group, or a hydrocarbon group with 1-20 carbon atoms (containing heteroatoms), an alkyloxy group with 1-20 carbon atoms (containing heteroatoms), or a alkylthio group with 1-20 carbon atoms (containing heteroatoms). When n2 is 2 or more, each R1 can be the same or different from the others. Multiple R1s can also bond to each other and form a ring together with the carbon atoms they are bonded to. X1 can be a single bond, ether bond, ester bond, or amide bond. In the formula, m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1, 2, 3 or 4, m5 is 0, 1, 2, 3 or 4, m6 is 0, 1, 2, 3, 4, 5 or 6, m7 is 0, 1, 2, 3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1, 2, 3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2, however, m1 When m1 is 0, then 0 ≤ m6 + m9 ≤ 4; when m1 is 1, then 0 ≤ m6 + m9 ≤ 6; when m2 is 0, then 0 ≤ m7 + m10 ≤ 4; when m2 is 1, then 0 ≤ m7 + m10 ≤ 6; when m3 is 0, then 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, then 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, then 0 ≤ m12 + m13 ≤ 4; when m11 is 1, then 0 ≤ m12 + m13 ≤ 6; and also, m4 + m12 ≥ 1. RF1 to RF3 are each independently a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms. When m5 is 2 or more, each RF1 can be the same or different from the others. When m6 is 2 or more, each RF2 can be the same or different from the others. When m7 is 2 or more, each RF3 can be the same or different from the others. R2~R5 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or hydrocarbon groups with 1~20 carbon atoms (containing heteroatoms), hydroxyl groups with 1~20 carbon atoms (containing heteroatoms), or thiol groups with 1~20 carbon atoms (containing heteroatoms). When m8 is 2, the two R2 atoms can be the same or different, and they can also bond to each other and form a ring with the carbon atoms they are bonded to. When m9 is 2, the two R3 atoms can be the same or different, and they can also bond to each other and form a ring with the carbon atoms they are bonded to. When m10 is 2, the two R4 atoms can be the same or different.Two R4 atoms can also bond to each other and form a ring together with the carbon atoms they are bonded to. When m13 is 2, two R5 atoms can be the same or different. Two R5 atoms can also bond to each other and form a ring together with the carbon atoms they are bonded to. Furthermore, aromatic rings directly bonded to S+ in strontium cations can also bond to each other and form a ring together with S+. LA and LB are each independently a single bond, ether bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. XL is a single bond, or may contain a hydrocarbon group with 1 to 40 carbon atoms of heteroatoms. In the formula, a1 is 0 or 1, a2 is 0, 1, or 2, a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4, a4 ​​is 1, 2, or 3, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R11 represents a halogen atom, a saturated hydrocarbon group with 1-6 carbon atoms that can be substituted with a halogen atom, a saturated hydrocarbon oxygen group with 1-6 carbon atoms that can be substituted with a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2-8 carbon atoms that can be substituted with a halogen atom. A1 represents a single bond or a saturated hydrocarbon group with 1-10 carbon atoms, and the -CH2- of this saturated hydrocarbon group can also be substituted with -O-.

2. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The strontium cation system represented by formula (A1-2) is represented by formula (A1-2-1), in which m4~m10, m12~m14, RF1~RF3, R2~R5, LA, LB and XL are the same as those mentioned above.

3. The chemical amplification positive inhibitor composition as described in claim 2, wherein, The strontium cation system represented by formula (A1-2-1) is represented by formula (A1-2-2), in which m4~m10, RF1~RF3 and R2~R5 are the same as those mentioned above.

4. The chemical amplification positive inhibitor composition as described in claim 1, wherein, The repeating unit represented by equation (A2) is represented by equation (A2-1), in which RA and a4 are the same as those mentioned above.

5. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer further comprises at least one repeating unit selected from the repeating units represented by formula (A3-1) and formula (A3-2), wherein b1 is 0 or 1, b2 is 0, 1 or 2, b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4, b4 is 1, 2 or 3, b5 is 0 or 1, RA is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R12 is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that may be substituted with a halogen atom, or a 1-6 carbon saturated hydrocarbon carbonyl group that may be substituted with a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl group that may be substituted with a halogen atom, and A2 is a single bond or a 1-10 carbon saturated hydrocarbon group, wherein a portion of the -CH2- of the saturated hydrocarbon group may also be substituted with -O-. When b4 is 1, X is an acid-labile group; when b4 is 2 or 3, X is independently either a hydrogen atom or an acid-labile group, but at least one of them is an acid-labile group; c1 is 0, 1, or 2; c2 is 0, 1, or 2; c3 is 0, 1, 2, 3, 4, or 5; c4 is 0, 1, or 2; R13 and R14 are independently hydrocarbon groups with 1 to 10 carbon atoms, which may also contain heteroatoms; R13 and R14 can also bond to each other and form a ring with the carbon atoms they are bonded to; R15 are independently fluorine atoms, fluorinated alkyl groups with 1 to 5 carbon atoms, or fluorinated alkoxy groups with 1 to 5 carbon atoms; R16 are independently hydrocarbon groups with 1 to 10 carbon atoms, which may also contain heteroatoms. A3 is a single bond, phenyl, naphthyl or *-C(=O)-O-A31-, where A31 is an aliphatic alkyl group, phenyl or naphthyl group with 1 to 20 carbon atoms. The aliphatic alkyl group may also include at least one selected from hydroxyl, ether, ester and lactone rings. * indicates an atomic bond with a carbon atom of the main chain.

6. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The polymer further comprises at least one repeating unit selected from the following formula (A4), the following formula (A5), and the following formula (A6), wherein d refers to 0, 1, 2, 3, 4, 5, or 6; e refers to 0, 1, 2, 3, or 4; f1 refers to 0 or 1; f2 refers to 0, 1, or 2; f3 refers to 0, 1, 2, 3, 4, or 5; RA refers to a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; and R17 and R18 are each independently a hydroxyl group, a halogen atom, a 1-6 carbon saturated hydrocarbon group that may be substituted with a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that may be substituted with a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that may be substituted with a halogen atom. R19 consists of halogen atoms, nitro, cyano, saturated hydrocarbon groups with 1 to 20 carbon atoms, saturated hydrocarbon oxygen groups with 1 to 20 carbon atoms, saturated hydrocarbon carbonyl oxygen groups with 2 to 20 carbon atoms, saturated hydrocarbon oxygen hydrocarbon groups with 2 to 20 carbon atoms, or saturated hydrocarbon thioalkyl hydrocarbon groups with 2 to 20 carbon atoms. When f2 is 1 or 2, it can also be a hydroxyl group. A4 consists of single bonds or saturated hydrocarbon groups with 1 to 10 carbon atoms. The -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

7. The chemical amplification positive inhibitor composition as claimed in claim 1, wherein, The (A) base polymer contains at least 60 mol% of repeating units with an aromatic ring skeleton among all repeating units of the polymer.

8. The chemical amplification positive inhibitor composition of claim 1 further includes (B) a quencher.

9. The chemical amplification positive inhibitor composition of claim 1 further includes (C) an organic solvent.

10. The chemical amplification positive inhibitor composition of claim 1 further comprises (D) a fluorine-containing polymer, wherein the (D) fluorine-containing polymer comprises: at least one repeating unit selected from the following formula (D1), the following formula (D2), the following formula (D3), and the following formula (D4), wherein h is 1, 2, or 3, RB are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R201, R202, R204, and R205 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. R203, R206, R207, and R208 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 R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, an ether bond or a carbonyl group can also be inserted between carbon-carbon bonds. Z1 is a (h+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (h+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms.

11. The chemical amplification positive inhibitor composition as claimed in claim 10, wherein, The fluorine-containing polymer further comprises at least one repeating unit selected from the repeating units represented by formula (D5) and formula (D6), where x is 1, 2, or 3, y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x, z is 0 or 1, RC are each independently a hydrogen atom or a methyl group, R209 is a hydrogen atom, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms that may have heteroatom groups inserted between carbon-carbon bonds, R210 is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms that may have heteroatom groups inserted between carbon-carbon bonds, R211 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 the saturated hydrocarbon group may also be replaced by an ester bond or an ether bond, Z2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-, Z3 series single bond, -O-, *-C(=O)-O-Z31-Z32- or *-C(=O)-NH-Z31-Z32-, Z31 series single bond or saturated hydrocarbon group with 1 to 10 carbon atoms, Z32 series single bond, ester bond, ether bond or sulfonamide bond, * series atomic bond with carbon atom of main chain.

12. The chemical amplification positive inhibitor composition of claim 1 further includes (E) an acid generating agent.

13. A method for forming a resist pattern, comprising the following steps: forming a resist film on a substrate using a chemically amplified positive resist composition as claimed in any one of claims 1 to 12, irradiating the resist film with a pattern using high-energy rays, and developing the irradiated resist film with an alkaline developer.

14. The method for forming a resist pattern as described in claim 13, wherein, The high-energy radiation system includes KrF excimer laser, ArF excimer laser, extreme ultraviolet radiation, or electron beam.

15. The method for forming a resist pattern as described in claim 13, wherein, The outermost surface of the substrate is composed of a material selected from at least one of chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten and tin.

16. The method for forming a resist pattern as described in claim 13, wherein, The substrate is a transmissive or reflective blank mask.

17. A transmissive blank mask, formed by coating a chemically amplified positive resist composition as claimed in any one of claims 1 to 12.

18. A reflective blank mask, formed by coating a chemically amplified positive resist composition as claimed in any one of claims 1 to 12.

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