Sulfonium salt, chemically amplified positive resist composition and resist pattern forming process

Abstract

The objective of this invention is to provide a chemical amplification positive resist composition that exhibits good solvent solubility and excellent lithography performance, such as resolution, LER, and pattern shape, in photolithography using high-energy rays, and a pattern formation method using the chemical amplification resist composition. The solution to this objective is a strontium salt, represented by the following formula (A).

Description

Technical Field

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

[0002] In recent years, the increasing integration of integrated circuits has led to a demand for finer pattern formation. Pattern processing below 0.2 μm primarily utilizes chemically amplified resist compositions with acid as a catalyst. Exposure sources at this stage can include high-energy rays such as ultraviolet light, far-ultraviolet light, and electron beams (EB). EB lithography, in particular, is used as an ultra-fine processing technique and is indispensable for the fabrication of blank photomasks in semiconductor manufacturing. The resist compositions used in such lithography include positive-type patterns formed by dissolving the exposed areas and negative-type patterns formed by leaving exposed areas. These are selected based on the desired resist pattern shape for ease of use.

[0003] Generally, EB (Edge Electrode) does not use a mask. For positive patterns, a method is used where a fine-area EB is sequentially irradiated onto areas other than the desired resist film residue. For negative patterns, the area where the resist film residue is to be retained is irradiated sequentially. This is a sweeping operation across the entire finely segmented area of ​​the processing surface, which is more time-consuming than a single exposure using a photomask. To avoid reducing throughput, the resist film must have high sensitivity. Furthermore, the longer etch time can easily lead to differences between the initial and later etched areas. The stability of the exposed portion in a vacuum over time is an important performance requirement. In addition, in the particularly important application of blank photomask processing, there are surface materials such as chromium compound films, represented by chromium oxide films deposited on the photomask substrate, which can easily affect the pattern shape of the chemically amplified resist film. To maintain high resolution and the etched shape, maintaining the rectangular pattern outline of the resist film regardless of the substrate type is also an important performance requirement.

[0004] The sensitivity and pattern profile control of the aforementioned resist films have been improved through various methods, 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 depending on the time until post-exposure heating (PEB), but a significant reason for time-dependent changes is 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, and therefore has been extensively explored.

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

[0006] Furthermore, Patent Documents 3-6 describe examples of controlling acid diffusion by bonding sulfonic acid generated during exposure to the resin used in the inhibitor composition. This method of introducing repeating units containing acid generated during exposure into the base polymer to suppress acid diffusion is effective in obtaining patterns with low line edge roughness (LER). However, depending on the structure and introduction rate of these repeating units, there are cases where the base polymer containing these repeating units exhibits problems with solubility in organic solvents.

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

[0008] Regarding the base polymers of resist compositions for positive EB lithography and EUV lithography, the main materials used are acid generated from a photoacid generator by irradiation with high-energy rays, which acts as a catalyst to deprotect the acidic functional groups (acid-decomposing protecting groups) of the phenolic side chains of the base polymer, making them soluble in alkaline developing solutions. The aforementioned acid-indestructible protecting groups mainly include tertiary alkyl groups, tertiary butoxycarbonyl groups, and acetal groups. While using protecting groups with lower activation energy 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 reduced dimensional uniformity of pattern linewidth (CDU).

[0009] With the recent advancements in the miniaturization of resist patterns, the control of acid diffusion generated by photoacid generators has become crucial, leading to the development of various acid diffusion control agents (quenchers). Examples of such quenchers include conventional amine compounds, as well as onium salt-type quenchers such as strontium and ferrophosphate salts. Patent Document 7 describes onium salts of carboxylic acids with nitrogen-containing heterocyclic structures such as indole. Furthermore, Patent Documents 8-10 propose quenchers derived from betaine-type onium salts with intramolecularly bonded phenylene oxide anions and carboxylate anions, similar to those of strontium and ferrophosphate cations. While these quenchers have demonstrated some performance improvement, satisfactory results have yet to be achieved. To meet future miniaturization requirements, the development of resist materials with excellent photolithography properties and pattern shapes is also anticipated. [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 [Patent Document 7] Japanese Patent No. 6515831 [Patent Document 8] Japanese Patent No. 6848776 [Patent Document 9] Japanese Patent No. 6583136 [Patent Document 10] Japanese Patent No. 6246480 Summary of the Invention

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

[0012] The present invention is made in view of the foregoing circumstances, and aims to provide a chemical amplification positive resist composition that has good solvent solubility and excellent lithography performance 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, and a pattern forming method using the chemical amplification resist composition. [Methods for solving problems]

[0013] After repeated and in-depth research in order to achieve the aforementioned objectives, the inventors of this case discovered that, in terms of quenching agents, using betaine-type strontium salts with 6-18 carbon chain alkyl groups or 4-18 carbon chain fluorinated alkyl groups and having strontium cations and carboxylate anions within the same molecule as the composition of the chemical amplification positive inhibitor has excellent solvent solubility, especially in EB lithography and EUV lithography, and excellent lithography performance such as resolution, LER, and pattern shape, thus completing this invention.

[0014] That is, the present invention provides the following strontium salt, chemically amplified positive inhibitor composition and inhibitor pattern formation method. 1. A strontium salt, represented by the following formula (A). [Chemistry 1] In the formula, n1 is 0 or 1. n2 is 0, 1, 2, 3 or 4. n3 is 0 or 1. n4 is 0, 1, 2, 3 or 4. LA can be a single bond, ether bond, ester bond, sulfonate bond, carbonate bond, or carbamate bond. Ralk is an alkyl group having 6 to 18 carbon atoms or a fluorinated alkyl group having 4 to 18 carbon atoms. When Ralk is an alkyl group having 6 to 18 carbon atoms, the alkyl group has at least one straight-chain structure with 6 or more carbon atoms. When Ralk is a fluorinated alkyl group having 4 to 18 carbon atoms, the fluorinated alkyl group has at least two groups selected from -CF2- and -CF3. Furthermore, a portion of the -CH2- group of the aforementioned alkyl and fluorinated alkyl groups may be substituted with an ether bond or a carbonyl group, and the aforementioned alkyl and fluorinated alkyl groups may also contain a ring structure selected from cyclopentane ring, cyclohexane ring, adamantane ring, norcamphenic ring, and benzene ring at the end or between carbon-carbon bonds. Ra is a halogen atom, or may be a hydrocarbon group with 1 to 30 carbon atoms containing heteroatoms. Furthermore, Ra and two of the two aromatic rings bonded to S+ in the formula may also bond to each other and form a ring together with the sulfur atoms they are bonded to. R1 can be a halogen atom, nitro, cyano, hydroxyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms. When n2 is 2, 3, or 4, each R1 can be the same or different, and multiple R1s can also bond to each other and form a ring together with the carbon atoms they are bonded to. R2 can be a halogen atom, nitro, cyano, hydroxyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms. When n4 is 2, 3, or 4, each R2 can be the same or different, and multiple R2s can also bond to each other and form a ring together with the carbon atoms they are bonded to. 2. As in 1., strontium salt is represented by the following formula (A1). [Chemistry 2] In the formula, n1~n4, LA, Ralk, Ra, R1 and R2 are the same as those mentioned above. n5 is 0 or 1. n6 is 0, 1, 2, 3 or 4. R3 can be a halogen atom, nitro, cyano, hydroxyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms. When n6 is 2, 3, or 4, each R3 can be the same or different, and multiple R3s can also bond to each other and form a ring together with the carbon atoms they are bonded to. 3. As in 2., strontium salt is represented by the following formula (A2). [Chemistry 3] In the formula, n2, n4, n6, LA, Ralk, Ra, R1, R2 and R3 are the same as those mentioned above. 4. A quenching agent composed of any one of the strontium salts described in 1 to 3. 5. A chemical amplification positive inhibitor composition containing a quencher as described in 4. 6. As in 5, the chemical amplification positive inhibitor composition further contains a base polymer that decomposes due to the action of acid and increases the solubility of the polymer in alkaline developer. 7. A chemically amplified positive inhibitor composition as described in 6, wherein the aforementioned polymer contains a repeating unit represented by the following formula (B1). [Chemistry 4] In the formula, a1 is 0 or 1. a2 is 0, 1 or 2. a3 is an integer that satisfies 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is 1, 2 or 3. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R11 can be a halogen atom, a nitro group, a carboxyl group, or a 1-6 carbon saturated hydrocarbon group that can be substituted by a halogen atom, or a 1-6 carbon saturated hydrocarbon oxygen group that can be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be substituted by a halogen atom. A1 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group can also be replaced by -O-. 8. A chemically amplified positive inhibitor composition as described in 6 or 7, wherein the aforementioned polymer contains a repeating unit represented by the following formula (B2-1). [Chemistry 5] In the formula, RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 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. R21 is a halogen atom, or a 1-6 carbon saturated hydrocarbon group that can be replaced by a halogen atom, or a 1-6 carbon saturated hydrocarbon oxygen group that can be replaced by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that can be replaced by a halogen atom. A2 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group can also be replaced by -O-. When X is 1, it is an acid-labile group; when X is 2 or 3, it is a hydrogen atom or an acid-labile group, but at least one of them is an acid-labile group. 9. A chemically amplified positive inhibitor composition as described in any of 6. to 8, wherein the aforementioned polymer contains a repeating unit represented by the following formula (B2-2). [Chemistry 6] In the formula, 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. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R22 and R23 are each an independent hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. R22 and R23 can also bond to each other and form a ring together with the carbon atoms they are bonded to. R24 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. R25 can be a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. A3 is a single bond, an enantiomer, an enantiomer, or *-C(=O)-O-A31-. A31 may also contain a hydroxyl group, an ether bond, an ester bond, or an lactone ring with 1 to 20 carbon atoms, an aliphatic enantiomer, or an enantiomer or an enantiomer; * is an atomic bond with a carbon atom of the main chain. 10. A chemical amplification positive inhibitor composition as described in any one of 6 to 9, wherein the aforementioned polymer contains at least one repeating unit selected from the repeating unit represented by formula (B3), the repeating unit represented by formula (B4), and the repeating unit represented by formula (B5). [Chemistry 7] In the formula, d is 0, 1, 2, 3, 4, 5, or 6. e is 0, 1, 2, 3, or 4. f1 is 0 or 1. f2 is 0, 1, or 2. f3 is 0, 1, 2, 3, 4, or 5. RA can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R31 and R32 are, independently, a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. R33 can be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxygen group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms, a saturated hydrocarbon oxy hydrocarbon group with 2 to 20 carbon atoms, a saturated hydrocarbon thio hydrocarbon group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a cyano group, and can also be a hydroxyl group when f2 is 1 or 2. A4 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group can also be replaced by -O-. 11. A chemical amplification positive inhibitor composition as described in any one of 6 to 10, wherein the aforementioned polymer contains at least one repeating unit selected from the following formula (B6), the following formula (B7), the following formula (B8), the following formula (B9), and the following formula (B10). [Chemistry 8] In the formula, g1 and g2 are independently 0, 1, 2 or 3. h1 is 0 or 1. h2 is 0, 1, 2, 3 or 4. h3 is 0, 1, 2, 3 or 4. However, when h1 is 0, 0 ≤ h2 + h3 ≤ 4, and when h1 is 1, 0 ≤ h2 + h3 ≤ 6. RA can be independently represented by a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 is a single bond or may have substituents such as phenyl groups. Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-NH-Z21-, or **-O-Z21-. Z21 is an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, or a divalent group obtained by combining them, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. Z3 can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z4 is a single bond, or an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, or a divalent group obtained by combining them, and may also contain halogen atoms, carbonyl groups, ester bonds, ether bonds, or hydroxyl groups. Z5 can be a single bond, or it can have substituents such as phenyl, naphthyl, or *-C(=O)-O-Z51-. Z51 is an aliphatic alkyl group, phenyl, or naphthyl group with 1 to 10 carbon atoms, and the aliphatic alkyl group may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings. Z6 can be a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z7 can be a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-. Z71 can also be an alkyl group with 1 to 20 carbon atoms and may contain heteroatoms. Z8 can be a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-. Z81 can also be a alkyl group with 1 to 20 carbon atoms and may contain heteroatoms. Z9 can be a single bond, methylene, ethyl, phenyl, fluorinated phenyl, trifluoromethyl-substituted phenyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-. Z91 can be an aliphatic phenyl group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or trifluoromethyl-substituted phenyl, and may also contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * indicates an atomic bond with a carbon atom in the main chain. ** indicates an atomic bond with Z1. *** indicates an atomic bond with Z6. **** indicates an atomic bond with Z7. L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Rf3 and Rf4 are independently hydrogen atoms, fluorine atoms, or fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, respectively. Rf5 and Rf6 are independently hydrogen atoms, fluorine atoms, or fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, respectively. However, not all Rf5 and Rf6 are simultaneously hydrogen atoms. Rf7 is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms. R41 and R42 are each independently hydrocarbon groups with 1 to 20 carbon atoms, and may also contain heteroatoms. Furthermore, R41 and R42 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. R43 is a halogen atom other than fluorine, or it may contain a hydrocarbon group with 1 to 20 carbon atoms and heteroatoms. When h3 is 2, 3 or 4, each R43 may be the same or different, and multiple R43s may also bond to each other and form a ring together with the carbon atoms they are bonded to. M- is a non-nucleophilic relative ion. A+ is an onium cation. 12. A chemically amplified positive inhibitor composition as described in any one of 6. to 11, wherein, in all repeating units of the polymer contained in the aforementioned base polymer, the content of repeating units having an aromatic ring skeleton is 60 mol% or more. 13. Any of the chemical amplification positive inhibitor compositions in items 5 to 12, further contain organic solvents. 14. Any of the chemical amplification positive inhibitor compositions in items 5 to 13 further contains a photoacid generator. 15. The chemical amplification positive inhibitor composition of any one of 5. to 14. further contains at least one repeating unit selected from the repeating unit represented by formula (E1), the repeating unit represented by formula (E2), the repeating unit represented by formula (E3) and the repeating unit represented by formula (E4), and may further contain a polymer containing fluorine atoms selected from the repeating unit represented by formula (E5) and the repeating unit represented by formula (E6). [Chemistry 9] In the formula, j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3. RB can be independently represented by a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. RC can be independently represented by a hydrogen atom or a methyl group. 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, independently, hydrogen atoms, hydrocarbon groups with 1 to 15 carbon atoms, fluorinated hydrocarbon groups with 1 to 15 carbon atoms, or acid-unstable groups. When R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, ether bonds or carbonyl groups can also be inserted between carbon-carbon bonds. R209 is a hydrogen atom, or it may be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms with heteroatoms inserted between carbon-carbon bonds. R210 can also be a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms, in which heteroatoms are 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 aforementioned saturated hydrocarbon group may also be replaced by an ester bond or an ether bond. Z1 is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms. Z2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * represents an atomic bond with a carbon atom in the main chain. 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 hydrocarbon group with 1 to 10 carbon atoms. Z32 is a single bond, ester bond, ether bond, or sulfonamide bond. * represents an atomic bond with a carbon atom in the main chain. 16. Any chemical amplification positive inhibitor composition as described in any of 5. to 15. further contains a quencher other than the quencher described in 4. 17. A method for forming a resist pattern, comprising the following steps: A resist film is formed on a substrate using a chemically amplified positive resist composition as described in any of 5.~16. The pattern was created by irradiating the aforementioned resist film with high-energy rays, and The resist film that has been irradiated with the aforementioned pattern is developed using an alkaline developer. 18. The resist patterning method of 17, wherein the aforementioned high-energy rays are EUV or EB with a wavelength of 3 to 15 nm. 19. The resist patterning method of 17 or 18, wherein the outermost surface of the aforementioned substrate is composed of a material containing chromium. 20. A method for forming a resist pattern as described in any one of 17 to 19, wherein the aforementioned substrate is a blank photomask. [Effects of the Invention]

[0015] The chemically amplified positive resist composition of this invention can provide patterns with extremely high resolution and low LER in microfabrication techniques, especially in EB lithography and EUV lithography. Furthermore, the resist pattern exhibits good rectangularity after formation, making it suitable as a chemically amplified positive resist material. Implementation

[0016] The present invention will now be described in detail. Furthermore, in the following description, the structure represented by the chemical formula may contain asymmetric carbon, and mirror-image isomers and non-mirror-image isomers may exist; in this case, it is indicated that each of these isomers is represented by a single formula. These isomers may be used individually or in mixtures of two or more.

[0017] [Salt] The strontium salt of this invention is represented by the following formula (A). [Chemistry 10]

[0018] In formula (A), 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, it is preferable to have a benzene ring with n1 = 0. n2 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, n2 is preferably 0, 1, or 2. n3 is 0 or 1. When n3 is 0, it is a benzene ring; when n3 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with n3 = 0. n4 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, n4 is preferably 0, 1, or 2.

[0019] In formula (A), LA can be a single bond, ether bond, ester bond, sulfonate bond, carbonate bond, or carbamate bond. Among these, single bonds, ether bonds, ester bonds, and sulfonate bonds are preferred, with ether bonds and ester bonds being more ideal.

[0020] In formula (A), Ralk is an alkyl group with 6 to 18 carbon atoms or a fluorinated alkyl group with 4 to 18 carbon atoms.

[0021] When Ralk is an alkyl group with 6 to 18 carbon atoms, the alkyl group has at least one straight-chain structure with 6 or more carbon atoms. Specific examples of alkyl groups with 6 to 18 carbon atoms represented by Ralk include: 1-hexyl, 1-heptyl, 1-octyl, 1-nonyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-tridecyl, 1-tetradecyl, 1-hexadecyl, 1-octadecyl, octane-2-yl, decane-2-yl, decane-4-yl, octadecane-8-yl, 7,7-dimethyloctyl, 7,7-diethylnonyl, 4-butyldodecyl, etc. Furthermore, a portion of the -CH2- group of the aforementioned alkyl groups may be replaced by an ether bond or a carbonyl group, and a ring structure may also be present at the end or between carbon-carbon bonds, for example, a cyclopentane ring, a cyclohexane ring, an adamantane ring, a norbornene ring, or a benzene ring. Ralk is preferably a straight-chain alkyl group or a straight-chain ethylene glycol dimethyl ether chain.

[0022] When Ralk is a fluorinated alkyl group having 4 to 18 carbon atoms, the fluorinated alkyl group has at least two groups selected from -CF2- and -CF3. Specific examples of fluorinated alkyl groups having 4 to 18 carbon atoms represented by Ralk include: 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, 1-nonyl, 1-decyl, 1-undecyl, 1-dodecyl, 1-tridecyl, 1-tetradecyl, 1-hexadecyl, 1-hexadecyl, 1-octadecyl, octane-2-yl, decane-2-yl, decane-4-yl, octadecane-8-yl, 7,7-dimethyloctyl, 7,7-diethylnonyl, 4-butyldodecyl, etc., in which some or all of the hydrogen atoms are replaced by fluorine atoms. Furthermore, a portion of the -CH2- group of the aforementioned fluorinated alkyl group may also be replaced by an ether bond or a carbonyl group, and its terminal or carbon-carbon bond may also have a ring structure, such as a cyclopentane ring, a cyclohexane ring, an adamantane ring, a norcamphor ring, or a benzene ring.

[0023] Ralk should be as shown below, but is not limited to these. Additionally, in the following formula, dashed lines represent atomic bonds. [Chemistry 11]

[0024] In formula (A), Ra is a halogen atom, or may contain a hydrocarbon group with 1 to 30 carbon atoms of heteroatoms.

[0025] Specific examples of halogen atoms represented by Ra include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0026] The hydrocarbon group represented by Ra can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, and tertiary butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, which should preferably be aryl. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0027] Furthermore, Ra and two of the two aromatic rings bonded to S+ in the formula can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, the structure of the aforementioned ring can be represented by the following formulas, etc. [Chemistry 12] In the formula, the dashed lines represent the atomic bonds between the substituent and the remaining substituent.

[0028] In formula (A), R1 can be a halogen atom, a nitro group, a cyano group, a hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, with fluorine or iodine atom being more preferred. Furthermore, the aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1-20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3-20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2-20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3-20 carbon atoms, such as cyclohexenyl; aryl groups with 6-20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7-20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them. 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, and a portion of 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 can result in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Also, when n2 is 2, 3, or 4, each R1 can be the same or different.

[0029] Furthermore, when n2 is 2, 3, or 4, 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, adamantane rings, etc. 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, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. The result can also include 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)-), haloalkyl groups, etc.

[0030] In formula (A), R2 can be a halogen atom, a nitro group, a cyano group, a hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, with fluorine or iodine atom being more preferred. Furthermore, the aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated using the same examples as the hydrocarbon group represented by R1, but are not limited to these. Also, when n4 is 2, 3, or 4, each R2 can be the same or different.

[0031] Furthermore, when n4 is 2, 3, or 4, multiple R2 atoms 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 can be cited as examples of rings formed by multiple R1 atoms bonded to each other and the carbon atoms they are bonded to, or similar examples, but are not limited to these.

[0032] The strontium salt represented by formula (A) should preferably be represented by the following formula (A1). [Chemistry 13] In the formula, n1~n4, LA, Ralk, Ra, R1 and R2 are the same as those mentioned above.

[0033] In formula (A1), n5 is 0 or 1. When n5 is 0, it is a benzene ring; when n5 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with n5 of 0. n6 is 0, 1, 2, 3, or 4. Considering the availability of raw materials, n6 is preferable to be 0, 1, or 2.

[0034] In formula (A1), R3 can be a halogen atom, a nitro group, a cyano group, a hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, with fluorine or iodine atom being more preferred. Furthermore, the aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given similarly to those illustrated in the description of formula (A) as hydrocarbon groups represented by R1, but are not limited to these examples. Also, when n6 is 2, 3, or 4, each R3 can be the same or different.

[0035] Furthermore, when n6 is 2, 3, or 4, multiple R3s 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 can be cited in the explanation of formula (A1) as examples of rings that can be formed by multiple R1s bonding to each other and together with the carbon atoms they are bonded to, but are not limited to this.

[0036] The strontium salt represented by formula (A1) should be represented by the following formula (A2). [Chemistry 14] In the formula, n2, n4, n6, LA, Ralk, Ra, R1, R2 and R3 are the same as those mentioned above.

[0037] Ideal examples of strontium salts represented by formula (A) can be listed below, but are not limited to these. [Chemistry 15]

[0038] [Chemistry 16]

[0039] [Chemistry 17]

[0040] [Chemistry 18]

[0041] [Chemistry 19]

[0042] [Chemistry 20]

[0043] [Chemistry 21]

[0044] [Chemistry 22]

[0045] [Chemistry 23]

[0046] [Chemistry 24]

[0047] [Chemistry 25]

[0048] [Chemistry 26]

[0049] [Chemistry 27]

[0050] [Chemistry 28]

[0051] [Chemistry 29]

[0052] [Chemistry 30]

[0053] [Chemistry 31]

[0054] The strontium salt of the present invention can be synthesized using known methods. Specifically, the synthesis method described in paragraph

[0019] of Japanese Patent No. 6583136 can be used, but it is not limited thereto.

[0055] The strontium salt represented by formula (A) is characterized by a basic carboxylate anion structure and a chain of 6-18 carbon alkyl groups or a chain of 4-18 carbon fluorinated alkyl groups on the aromatic ring forming the strontium cation. It is believed that the aforementioned alkyl and fluorinated alkyl groups increase solvent solubility and have high lipid solubility, therefore the strontium salt represented by formula (A) will be distributed in the upper layer of the resist film. Especially in EB lithography, when depicting an electron beam, the forward scattering effect caused by the electron beam cannot be avoided in the exposed area. When using conventional quenchers, there is a concern that the deprotection reaction in the upper part of the pattern may be excessive, resulting in a rounded shape at the top of the pattern. However, by using the quencher of this invention, excessive deprotection reaction in the upper part of the pattern can be effectively suppressed, and the pattern can be corrected to a rectangle. Furthermore, the high basicity of the carboxylate anion located within the same molecule can control the acid diffusion of the generated acid and effectively quench it. It is believed that by utilizing these synergistic effects, when using the strontium salt of the present invention, patterns with good resolution, high contrast, good CDU, and small LER can be obtained, as well as patterns with good rectangularity.

[0056] The strontium salt of this invention can be ideally used as a quenching agent.

[0057] [Chemical Amplification Positive Inhibitor Composition] [(A) Quenching agent] The chemically amplified positive resist composition of the present invention, in terms of component (A), contains a quencher composed of a strontium salt represented by formula (A) as an essential component. Furthermore, in the present invention, the quencher refers to a compound that captures the acid that generates the acid-generating agent. This suppresses the diffusion rate of the acid that generates the acid-generating agent within the resist film, and even when using a substrate whose outermost surface is made of a chromium-containing material, the effect of the acid generated within the resist film on the chromium-containing material can still be suppressed.

[0058] In the chemical amplification positive inhibitor composition of this invention, the content of (A) quencher relative to 80 parts by mass of the base polymer (B) described later is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass. If the content of the quencher is within the aforementioned range, the generated acid can be effectively captured, and a good pattern shape can be obtained. Furthermore, storage stability is also good. (A) Quencher can be used alone or in combination of two or more.

[0059] [(B) Basic Polymer] The inhibitor composition of the present invention contains a base polymer as component (B), which includes a polymer that decomposes due to the action of acid and increases the solubility of alkaline developer.

[0060] The aforementioned polymer is preferably a polymer containing repeating units represented by the following formula (B1) (hereinafter also referred to as repeating unit B1). [Chemistry 32]

[0061] In formula (B1), a1 is 0 or 1. a2 is 0, 1, or 2; when it is 0, it represents the benzene skeleton; when it is 1, it represents the naphthalene skeleton; and when it is 2, it 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, it is preferable that a3 is 0, 1, 2, or 3, and a4 is 1, 2, or 3. When a2 is 1 or 2, it is preferable that a3 is 0, 1, 2, 3, or 4, and a4 is 1, 2, or 3.

[0062] In formula (B1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0063] In formula (B1), R11 can be a halogen atom, a nitro group, a carboxyl group, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The saturated hydrocarbon group, as well as the saturated hydrocarbon oxygen group and the saturated hydrocarbon carbonyl oxygen group, can be any of the following: 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 them. 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.

[0064] In formula (B1), A1 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group may also be replaced by -O-. The aforementioned saturated alkyl group can be any of the following: 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, etc., alkyl diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, etc., cyclic saturated alkyl groups with 3 to 10 carbon atoms; and groups obtained by combining them. When the aforementioned saturated alkyl group contains an ether bond, when a1 in formula (B1) is 1, it can be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to 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 other than between the carbon atom at the α-position and the carbon atom at the β-position relative to this ether oxygen atom. In addition, 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 more ideal.

[0065] 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., it does not have a linker group (-C(=O)-O-A1-)), ideal examples of repeating unit B1 can be listed from units such as 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, and 6-hydroxy-2-vinylnaphthalene. Specifically, examples can be listed below, but are not limited thereto. In addition, RA in the following formula is the same as described above. [Chemistry 33]

[0066] [Chemistry 34]

[0067] [Chemistry 35]

[0068] When a1 is 1 (i.e., has -C(=O)-O-A1- as a linking basis), ideal examples of repeating unit B1 can be listed as follows, but are not limited to these. In addition, RA is the same as above in the following formula. [Chemistry 36]

[0069] [Chemistry 37]

[0070] [Chemistry 38]

[0071] [Chemistry 39]

[0072] [Chemistry 40]

[0073] The content of repeating unit B1 in all repeating units constituting the aforementioned polymer is preferably 15-90 mol%, and more preferably 15-80 mol%. However, if the polymer described later contains at least one of the repeating units represented by formula (B3) and formula (B4) that provide higher etch resistance, and if the unit has a phenolic hydroxyl group as a substituent, its ratio should also be added and set within the aforementioned range. Repeating unit B1 may be used alone or in combination of two or more.

[0074] In order to provide the characteristic that the exposed part of the aforementioned polymer can be dissolved in alkaline developer as a positive resist component, it is advisable to contain repeating units with acidic functional groups protected by acid-instable groups, that is, repeating units that are protected by acid-instable groups and become alkali-soluble due to the action of acid (hereinafter also referred to as repeating unit B2).

[0075] The most ideal example of repeating unit B2 can be represented by the following formula (B2-1) (hereinafter also called repeating unit B2-1). [Chemistry 41]

[0076] In formula (B2-1), b1 is 0 or 1. b2 is 0, 1, or 2; when b2 is 0, it represents the benzene skeleton; when b2 is 1, it represents naphthalene; and when b2 is 2, it represents anthracene. 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, b3 should ideally be 0, 1, 2, or 3, and b4 should be 1, 2, or 3. When b2 is 1 or 2, b3 should ideally be 0, 1, 2, 3, or 4, and b4 should be 1, 2, or 3.

[0077] In formula (B2-1), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0078] In formula (B2-1), R21 can be a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxy group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxy group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The aforementioned saturated hydrocarbon group, as well as the saturated hydrocarbon carbonyl oxy group and the saturated hydrocarbon oxy group, can be any of the following: 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 them. If the number of carbon atoms is below the upper limit, the solubility in alkaline developing solutions is good. When b3 is 2 or more, each R21 can be the same or different.

[0079] In formula (B2-1), A2 is a single bond or a saturated alkyl group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated alkyl group may be replaced by -O-. The aforementioned saturated alkyl group can be any of the following: 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, etc., alkyl diyl groups with 1 to 10 carbon atoms; cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, cyclohexane diyl, etc., cyclic saturated alkyl groups with 3 to 10 carbon atoms; and groups obtained by combining them. When the aforementioned saturated alkyl group contains an ether bond, when b1 in formula (B2-1) is 1, it can be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the ester oxygen atom. Furthermore, when b1 is 0, the atom bonded to the main chain becomes an ether oxygen atom, and a second ether bond can be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to this ether oxygen atom. In addition, if the number of carbon atoms in the aforementioned saturated hydrocarbon group is 10 or less, sufficient solubility in alkaline developing solutions can be obtained, which is more ideal.

[0080] In formula (B2-1), 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 independently, but at least one is an acid-indestructible group. That is, the repeating unit B2-1 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 group can be used without particular restriction if it is one of the well-known chemical amplification positive inhibitor compositions that is deactivated by acid to provide an acidic group.

[0081] Examples of the aforementioned acid-labile groups include tertiary saturated hydrocarbon groups. For the purpose of obtaining the monomers for polymerization by distillation, the aforementioned tertiary saturated hydrocarbon groups should preferably have 4 to 18 carbon atoms.

[0082] The saturated hydrocarbon groups bonded to the aforementioned tertiary carbon atoms 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 their carbon-carbon bonds may also contain ether bonds, carbonyl groups, or other functional groups containing oxygen atoms. 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 they are bonded to.

[0083] Examples of the aforementioned alkyl substituents include: methyl, ethyl, propyl, adamantyl, norbornel, tetrahydrofuran-2-yl, 7-oxanorborne-2-yl, cyclopentyl, 2-tetrahydrofuranyl, tricyclo[5.2.1.02,6]decyl, 8-ethyl-8-tricyclo[5.2.1.02,6]decyl, 3-methyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, tetracyclo[4.4.0.12,5.17,10]dodecyl, 3-sideoxy-1-cyclohexyl, etc.

[0084] The aforementioned tertiary saturated hydrocarbon groups can be listed as follows: tertiary butyl, tertiary pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1-adamantyl-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 Hexyl, 2-methyl-2-norborneol, 2-ethyl-2-norborneol, 8-methyl-8-tricyclo[5.2.1.02,6]decyl, 8-ethyl-8-tricyclo[5.2.1.02,6]decyl, 3-methyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, 3-ethyl-3-tetracyclo[4.4.0.12,5.17,10]dodecyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 1-methyl-3-sideoxy-1-cyclohexyl, 1-methyl-1-(tetrahydrofuran-2-yl)ethyl, 5-hydroxy-2-methyl-2-adamantyl, 5-hydroxy-2-ethyl-2-adamantyl, but not limited to these.

[0085] Furthermore, the aforementioned acid-indestructible groups can be exemplified by groups represented by formula (B2-1-1). Groups represented by formula (B2-1-1) are often used as acid-indestructible groups, and are a useful option as acid-indestructible groups that stably provide a more rectangular pattern at the interface between the pattern and the substrate. When X is a group represented by formula (B2-1-1), an acetal structure is formed. [Chemistry 42] In the formula, the dashed lines represent atomic bonds.

[0086] In formula (B2-1-1), RL1 is a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[0087] RL1 is appropriately selected based on the sensitivity design to the decomposability of acids. For example, if the design aims to ensure high stability while allowing for decomposition by strong acids, a group with a hydrogen atom or a carbon atom bonded to the acetal carbon is preferable. Examples of RL1 groups with tertiary carbon atom bonded to the acetal carbon include tertiary butyl, tertiary pentyl, and 1-adamantyl, but are not limited to these. If the design aims for high sensitivity to pH changes and higher reactivity, a straight-chain alkyl group is preferable. Although it also depends on the combination of acid generators and quenchers incorporated into the inhibitor composition, for RL2, when a larger alkyl group is selected at the end and the solubility change due to decomposition is significant, RL1 should ideally have a secondary carbon atom bonded to the acetal carbon. Examples of RL1 groups with secondary carbon atom bonded to the acetal carbon include isopropyl, secondary butyl, cyclopentyl, and cyclohexyl, but are not limited to these.

[0088] In formula (B2-1-1), RL2 is a hydrocarbon group with 1 to 30 carbon atoms. This hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, a portion of the -CH2- group can be replaced by heteroatoms such as oxygen or sulfur atoms, resulting in ether bonds or thioether bonds. 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. Especially in the formation of fine patterns, to obtain higher resolution, RL2 should preferably be a hydrocarbon group with 1 to 6 carbon atoms. When RL2 is a hydrocarbon group with 1 to 6 carbon atoms, the alcohol generated after the acid-induced deprotection reaction is water-soluble. Therefore, when using an alkaline developer to form a positive pattern, it will dissolve in the developer, thus suppressing residual defects in the exposed area.

[0089] Ideal examples of the basis represented by equation (B2-1-1) can be listed below, but are not limited to these. Furthermore, in the following equation, RL1 is the same as described above, and dashed lines represent atomic bonds. [Chemistry 43]

[0090] [Chemistry 44]

[0091] Other acid-labile groups can also be formed by replacing the hydrogen atom of the phenolic hydroxyl group with -CH2COO- (a tertiary saturated hydrocarbon group). In this case, the aforementioned tertiary saturated hydrocarbon group can be the same as the tertiary saturated hydrocarbon group used for the protection of the aforementioned phenolic hydroxyl group.

[0092] Furthermore, repeating unit B2 can also be represented by the following formula (B2-2) (hereinafter also referred to as repeating unit B2-2). The dissolution rate of repeating unit B2-2 in the exposure section will be higher, so it is a useful option as a unit containing acid unstable groups that provides good performance for linewidth variation of development load. [Chemistry 45]

[0093] In equation (B2-2), 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.

[0094] In formula (B2-2), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0095] In formula (B2-2), R22 and R23 are each independently a hydrocarbon group with 1 to 10 carbon atoms that may also contain heteroatoms, and R22 and R23 may also bond to each other and form a ring together with the carbon atoms they are bonded to.

[0096] In formula (B2-2), R24 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.

[0097] In formula (B2-2), R25 can be a hydrocarbon group with 1 to 10 carbon atoms that may also contain heteroatoms.

[0098] In formula (B2-2), A3 is a single bond, an enylphenyl, an enylnaphthyl, or *-C(=O)-O-A31-. A31 may also be an aliphatic enyl group with 1 to 20 carbon atoms, containing a hydroxyl group, an ether bond, an ester bond, or an lactone ring, or an enylphenyl or enylnaphthyl. * indicates an atomic bond with a carbon atom in the main chain.

[0099] Ideal examples of repeating unit B2-2 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 46]

[0100] [Chemistry 47]

[0101] The content of repeating unit B2 in all repeating units constituting the aforementioned polymer is preferably 5-95 mol%, and more preferably 20-80 mol%. Repeating unit B2 can be used alone or in combination of two or more types.

[0102] The aforementioned polymer may also contain at least one of the repeating units represented by the following formula (B3) (hereinafter also referred to as repeating unit B3), the repeating unit represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), and the repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5). [Chemistry 48]

[0103] In equations (B3) and (B4), d is 0, 1, 2, 3, 4, 5, or 6. e is 0, 1, 2, 3, or 4.

[0104] In formulas (B3) and (B4), R31 and R32 are independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group with 1 to 6 carbon atoms that can be substituted by a halogen atom, a saturated hydrocarbon oxygen group with 1 to 6 carbon atoms that can be substituted by a halogen atom, or a saturated hydrocarbon carbonyl oxygen group with 2 to 8 carbon atoms that can be substituted by a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxygen group, and saturated hydrocarbon carbonyl oxygen group can be any of the following: linear, branched, or cyclic. When d is 2 or more, each R31 can be the same or different from the others. When e is 2 or more, each R32 can be the same or different from the others.

[0105] In formula (B5), f1 is 0 or 1. f2 is 0, 1 or 2; when it is 0, it is a benzene skeleton; when it is 1, it is a naphthalene skeleton; and when it is 2, it is an 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.

[0106] In formula (B5), RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0107] In formula (B5), R33 can be a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxy group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, a saturated hydrocarbon oxyalkyl group with 2 to 20 carbon atoms, a saturated hydrocarbon thioalkyl group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a cyano group. When f2 is 1 or 2, it can also be a hydroxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxyalkyl group, saturated hydrocarbon carbonyl oxyalkyl group, saturated hydrocarbon oxyalkyl group, and saturated hydrocarbon thioalkyl group can be any of the following: linear, branched, or cyclic. When f3 is 2 or more, each R33 can be the same or different from the others.

[0108] In formula (B5), A4 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group may also be replaced by -O-. The aforementioned saturated hydrocarbon group can be any of the following: linear, branched, or cyclic. Specific examples can be given as those illustrated in the description of A1 in formula (B1).

[0109] When at least one of repeating units B3 to B5 is used as a constituent unit of the aforementioned polymer, in addition to obtaining 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.

[0110] To achieve the effect of improving etching resistance, the content of repeating units B3 to B5 should preferably be 5 mol% or more in all repeating units constituting the aforementioned polymer. Furthermore, the content of repeating units B3 to B5 in all repeating units constituting the aforementioned polymer should preferably be 25 mol% or less, and preferably 20 mol% or less. If the amount introduced when there is no functional group, or when the functional group is other than hydroxyl, is 25 mol% or less, there will be no concern about development defects, which is therefore ideal. Repeating units B3 to B5 can be used alone or in combination of two or more.

[0111] If the aforementioned polymer contains repeating units B1, B2, and at least one of repeating units selected from B3 to B5, it is ideal to achieve a good balance between high etch resistance and resolution. In this case, these repeating units should preferably contain 60 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more in all the repeating units of the aforementioned polymer.

[0112] The aforementioned polymer may also contain at least one of the following: repeating unit represented by formula (B6) (hereinafter also referred to as repeating unit B6), repeating unit represented by formula (B7) (hereinafter also referred to as repeating unit B7), repeating unit represented by formula (B8) (hereinafter also referred to as repeating unit B8), repeating unit represented by formula (B9) (hereinafter also referred to as repeating unit B9), and repeating unit represented by formula (B10) (hereinafter also referred to as repeating unit B10). [Chemistry 49]

[0113] In formulas (B6) to (B10), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 is a single bond or may be a phenyl group with substituents. Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-NH-Z21-, or **-O-Z21-. Z21 is an aliphatic alkyl group with 1 to 6 carbon atoms, a phenyl group, or a divalent group obtained by combining them, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z3 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. Z4 is a single bond, or an aliphatic alkyl group with 1 to 6 carbon atoms, a phenyl group, or a divalent group obtained by combining them, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z5 is independently a single bond, or may contain substituents such as phenyl, naphthyl, or *-C(=O)-O-Z51-. Z51 is an aliphatic alkyl group, phenyl, or naphthyl with 1 to 10 carbon atoms, and this aliphatic alkyl group may also contain a halogen atom, hydroxyl group, ether bond, ester bond, or lactone ring. Z6 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-. Z71 is an alkyl group with 1 to 20 carbon atoms, and may also contain heteroatoms. Z8 is independently a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-. Z81 is an alkyl group with 1 to 20 carbon atoms, which may also contain heteroatoms. Z9 is a single bond, methylene, ethyl alkyl, phenyl alkyl, fluorinated phenyl alkyl, phenyl alkyl substituted with trifluoromethyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-. Z91 is an aliphatic alkyl group with 1 to 6 carbon atoms, phenyl alkyl, fluorinated phenyl, or phenyl substituted with trifluoromethyl, and may also contain carbonyl, ester, ether, or hydroxyl groups. * indicates an atomic bond with a carbon atom in the main chain. ** indicates an atomic bond with Z1. *** indicates an atomic bond with Z6. **** indicates an atomic bond with Z7.

[0114] Z21, Z51, and Z91 represent aliphatic alkyl groups that 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, 1,1-dimethylethane-1,2-diyl, pentane-1,5-diyl, 2-methylbutane-1,2-diyl, hexane-1,6-diyl, etc.; cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, etc.; and groups obtained by combining them.

[0115] Z71 and Z81 can also contain heteroatoms, and the extended hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples are listed below, but are not limited to these. [Transformation 50] In the formula, the dashed lines represent atomic bonds.

[0116] In formula (B6), R41 and R42 are each independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be 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, secondary butyl, and tertiary butyl; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 20 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining them, which are preferably aryl groups. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Also, some of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it 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, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0117] Furthermore, R41 and R42 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. Specific examples of the aforementioned rings can be shown in the following formulas, etc. [Chemistry 51] In the formula, the dashed line represents the atomic bond between Z and Z4.

[0118] Specific examples of the cations in repeating unit B6 can be listed below, but are not limited thereto. Furthermore, in the following formula, RA is the same as described above. [Chemistry 52]

[0119] [Chemistry 53]

[0120] [Chemistry 54]

[0121] [Chemistry 55]

[0122] [Chemistry 56]

[0123] [Chemistry 57]

[0124] [Chem.58]

[0125] [Chemistry 59]

[0126] [Transformation 60]

[0127] [Chemistry 61]

[0128] In formula (B6), M- represents a non-nucleophilic relative ion. The aforementioned non-nucleophilic relative ions are preferably halide ions, sulfonate anions, aceimide anions, and methylated acid anions. Specific examples of the aforementioned halide ions include chloride ions, bromide ions, etc. Specific examples of the aforementioned sulfonate anions (sulfonate ions) include: trifluoromethanesulfonate ions, 1,1,1-trifluoroethanesulfonate ions, nonafluorobutanesulfonate ions, and other fluoroalkyl sulfonate ions; toluenesulfonate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, 1,2,3,4,5-pentafluorobenzenesulfonate ions, and other aryl sulfonate ions; methanesulfonate ions, butanesulfonate ions, and other alkyl sulfonate ions, etc. Specific examples of the aforementioned aceimide anions (aceimide ions) include: bis(trifluoromethylsulfonyl)aceimide ion, bis(perfluoroethylsulfonyl)aceimide ion, bis(perfluorobutylsulfonyl)aceimide ion, etc. Specific examples of the aforementioned methylated anions (methylated ions) include: trifluoromethylsulfonyl methylated ion, trifluoroethylsulfonyl methylated ion, etc.

[0129] Other examples of the aforementioned non-nucleophilic relative ions can be listed as anions represented by any of the formulas (B6-1) to (B6-4). [Chemistry 62]

[0130] In formula (B6-1), Rfa is a fluorine atom, or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be listed and illustrated as examples of hydrocarbon groups represented by Rfa1 in the following formula (B6-1-1).

[0131] The anion represented by formula (B6-1) should preferably be represented by the following formula (B6-1-1). [Chemistry 63]

[0132] In formula (B6-1-1), Q1 and Q2 are independently hydrogen atoms, fluorine atoms, or fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, respectively. To improve solvent solubility, at least one of them is preferably trifluoromethyl. m can be 0, 1, 2, 3, or 4, with 1 being particularly preferred. Rfa1 can also be a hydrocarbon group with 1 to 35 carbon atoms containing heteroatoms. The aforementioned heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., with oxygen atoms being more preferred. Considering the high resolution that can be obtained in the formation of fine patterns, the aforementioned hydrocarbon groups are preferably those with 6 to 30 carbon atoms.

[0133] In formula (B6-1-1), Rfa1 represents a hydrocarbon group with 1 to 35 carbon atoms that can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 35 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-enyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0134] 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, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. This can result in the presence of hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Specific examples of hydrocarbon groups containing heteroatoms include: tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-sideoxypropyl, 4-sideoxy-1-adamantyl, 3-sideoxycyclohexyl, etc.

[0135] In formula (B6-1-1), La1 can be a single bond, ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond. From a synthetic point of view, it is preferable to be an ether bond or an ester bond, with an ester bond being even better.

[0136] Specific examples of anions represented by formula (B6-1) are shown below, but are not limited to these. Additionally, in the following formula, Q1 is the same as described above, and Ac is acetyl. [Chemistry 64]

[0137] [Chemistry 65]

[0138] [Chemistry 66]

[0139] [Chemistry 67]

[0140] [Chemistry 68]

[0141] [Chemistry 69]

[0142] [Chemistry 70]

[0143] [Chemistry 71]

[0144] [Chemistry 72]

[0145] [Chemistry 73]

[0146] In formula (B6-2), Rfb1 and Rfb2 are each independently a fluorine atom, or may contain heteroatoms of 1 to 40 carbon atoms, and are hydrocarbons. The aforementioned hydrocarbons may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples can be given and illustrated by the same example of the hydrocarbon represented by Rfa1 in formula (B6-1-1). Rfb1 and Rfb2 are preferably fluorine atoms or linear fluorinated alkyl groups having 1 to 4 carbon atoms. Furthermore, Rfb1 and Rfb2 can also bond to each other and form a ring together with the group they bond to (-CF2-SO2-N--SO2-CF2-). In this case, the group obtained by the mutual bonding of Rfb1 and Rfb2 should preferably be fluorinated ethyl or fluorinated propyl.

[0147] In formula (B6-3), Rfc1, Rfc2, and Rfc3 are each independently a fluorine atom, or may contain heteroatoms and be a hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given and illustrated by the same example as the hydrocarbon group represented by Rfa1 in formula (B6-1-1). Rfc1, Rfc2, and Rfc3 are preferably fluorine atoms or linear fluorinated alkyl groups with 1 to 4 carbon atoms. Furthermore, Rfc1 and Rfc2 can also be bonded to each other and form a ring together with the group they are bonded to (-CF2-SO2-C--SO2-CF2-). In this case, the group formed by the mutual bonding of Rfc1 and Rfc2 is preferably fluorinated ethyl or fluorinated propyl.

[0148] In formula (B6-4), Rfd is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as hydrocarbon groups represented by Rfa1 in formula (B6-1-1).

[0149] Specific examples of anions represented by formula (B6-4) can be listed below, but are not limited to these. [Chemistry 74]

[0150] [Chemistry 75]

[0151] The aforementioned examples of non-nucleophilic relative ions can be further illustrated by anions having aromatic rings substituted with iodine or bromine atoms. Specific examples of such anions can be represented by the following formula (B6-5). [Chemistry 76]

[0152] In equation (B6-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3. However, 1 ≤ y + z ≤ 5. y should ideally be 1, 2, or 3, with 2 or 3 being better. z should ideally be 0, 1, or 2.

[0153] In formula (B6-5), XBI is an iodine atom or a bromine atom, and when x and / or y are 2 or more, they can be the same or different.

[0154] In formula (B6-5), L11 is a single bond, ether bond, or ester bond, or may contain a saturated alkyl group with 1 to 6 carbon atoms that is an ether bond or ester bond. The aforementioned saturated alkyl group may be linear, branched, or cyclic.

[0155] In formula (B6-5), L12 is a single bond or a divalent linker with 1 to 20 carbon atoms when x is 1, and a (x+1) valent linker with 1 to 20 carbon atoms when x is 2 or 3, and the linker may also contain oxygen, sulfur or nitrogen atoms.

[0156] In formula (B6-5), Rfe is a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a 1-20 carbon-1 hydrocarbon group, a 1-20 carbon-1 hydrocarbon-oxy group, a 2-20 carbon-1 hydrocarbon-carbonyl group, a 2-20 carbon-1 hydrocarbon-oxycarbonyl group, a 2-20 carbon-1 hydrocarbon-carbonyloxy group, or a 1-20 carbon-1 hydrocarbon-sulfonyloxy group, or -N(RfeA)(RfeB), -N(RfeC)-C(=O)-RfeD, or -N(RfeC)-C(=O)-O-RfeD. RfeA and RfeB are each independently a hydrogen atom or a 1-6 carbon-1 saturated hydrocarbon group. RfeC is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxy group having 2 to 6 carbon atoms. RfeD is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyl oxy group, and hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic. When x and / or z are 2 or more, each Rfe may be the same or different.

[0157] Among them, Rfe should preferably be a hydroxyl group, -N(RfeC)-C(=O)-RfeD, -N(RfeC)-C(=O)-O-RfeD, a fluorine atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, etc.

[0158] In formula (B6-5), Rf11 to Rf14 are independently hydrogen atoms, fluorine atoms, or trifluoromethyl groups, with at least one of them being a fluorine atom or a trifluoromethyl group. Furthermore, Rf11 and Rf12 can also combine to form a carbonyl group. It is particularly desirable for Rf13 and Rf14 to both be fluorine atoms.

[0159] Specific examples of anions represented by formula (B6-5) are shown below, but are not limited to these. Furthermore, in the following formula, XBI is the same as described above. [Chemistry 77]

[0160] [Chemistry 78]

[0161] [Chemistry 79]

[0162] [Chemistry 80]

[0163] [Chemistry 81]

[0164] [Chemistry 82]

[0165] [Chemistry 83]

[0166] [Chemistry 84]

[0167] [Chemistry 85]

[0168] [Chemistry 86]

[0169] [Chemistry 87]

[0170] [Chemistry 88]

[0171] [Chemistry 89]

[0172] [Chemistry 90]

[0173] [Chemistry 91]

[0174] [Chemistry 92]

[0175] [Chemistry 93]

[0176] [Chemistry 94]

[0177] [Chem. 95]

[0178] [Chemistry 96]

[0179] [Chemistry 97]

[0180] [Chem. 98]

[0181] [Chemistry 99]

[0182] The aforementioned non-nucleophilic relative ions may also include the fluorobenzenesulfonate anion bonded to an aromatic group containing an iodine atom as described in Japanese Patent No. 6648726, the anion with an acid-decomposition mechanism as described in International Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692, the anion with a cyclic ether group as described in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935, and the anion as described in Japanese Patent Application Publication No. 2018-92159.

[0183] The aforementioned non-nucleophilic relative ions may also be the bulky benzenesulfonic acid derivative anions without fluorine atoms described in Japanese Patent Application Publication No. 2006-276759, Japanese Patent Application Publication No. 2015-117200, Japanese Patent Application Publication No. 2016-65016 and Japanese Patent Application Publication No. 2019-202974, the benzenesulfonate anion without fluorine atoms bonded to an aromatic group containing iodine atoms, and the alkylsulfonate anion described in Japanese Patent No. 6645464.

[0184] The aforementioned non-nucleophilic relative ions may also be the anions of disulfonic acid described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonic acid on one side and sulfenamide or sulfenimide on the other side as described in International Patent Application Publication No. 2020 / 158366, and the anions of sulfonic acid on one side and carboxylic acid on the other side as described in Japanese Patent Application Publication No. 2015-24989.

[0185] In equations (B7) and (B8), g1 and g2 are independently 0, 1, 2 or 3, and it is preferable to be 1.

[0186] In equation (B9), h1 is 0 or 1. h2 is 0, 1, 2, 3 or 4. h3 is 0, 1, 2, 3 or 4. However, when h1 is 0, 0 ≦ h2 + h3 ≦ 4, and when h1 is 1, 0 ≦ h2 + h3 ≦ 6.

[0187] In formulas (B7), (B8), and (B9), L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, from a synthetic point of view, ether bond, ester bond, and carbonyl group are preferable, with ester bond and carbonyl group being even more preferred.

[0188] In formula (B7), Rf1 and Rf2 are each independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among them, Rf1 and Rf2 are preferably both fluorine atoms to improve the acid strength of the generated acid. Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. Among them, to improve solvent solubility, at least one of Rf3 and Rf4 is preferably trifluoromethyl.

[0189] In formula (B8), Rf5 and Rf6 are independently hydrogen atoms, fluorine atoms, or fluorinated saturated hydrocarbon groups having 1 to 6 carbon atoms, respectively. However, not all of Rf5 and Rf6 are simultaneously hydrogen atoms. Among them, to improve solvent solubility, at least one of Rf5 and Rf6 should preferably be trifluoromethyl.

[0190] In formula (B9), Rf7 is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms. Rf7 is preferably a fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethyl thio, or difluoromethyl thio, with fluorine atom, trifluoromethyl, or trifluoromethoxy being more preferred. When h2 is 2, 3, or 4, each Rf7 can be the same or different.

[0191] In formula (B9), R43 is a halogen atom other than fluorine, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given similarly to those illustrated in the explanation of formula (A) where the hydrocarbon group is represented by R1, but are not limited thereto. Furthermore, when h3 is 2, 3, or 4, each R43 can be the same or different.

[0192] Furthermore, when h3 is 2, 3, or 4, multiple R43 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, adamantane rings, etc. 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, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. The result can also include 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)-), haloalkyl groups, etc.

[0193] Specific examples of the anion of repeating unit B7 can be listed below, but are not limited to these. Additionally, in the following formula, RA is the same as described above, and Me is a methyl group. [Chemistry 100]

[0194] [Chemistry 101]

[0195] [Chemistry 102]

[0196] [Chemistry 103]

[0197] [Chemistry 104]

[0198] [Chemistry 105]

[0199] [Chemistry 106]

[0200] [Chemistry 107]

[0201] [Chemistry 108]

[0202] [Chemistry 109]

[0203] [Chemical 110]

[0204] [Chemistry 111]

[0205] [Chemistry 112]

[0206] Specific examples of anions in the repeating unit B8 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 113]

[0207] [Chemistry 114]

[0208] [Chemistry 115]

[0209] [Chemistry 116]

[0210] [Chemistry 117]

[0211] [Chemistry 118]

[0212] [Chemistry 119]

[0213] [Chemistry 120]

[0214] [Chemistry 121]

[0215] [Chemistry 122]

[0216] [Chemistry 123]

[0217] Specific examples of the anion of repeating unit B9 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 124]

[0218] [Chemistry 125]

[0219] [Chemistry 126]

[0220] [Chemistry 127]

[0221] [Chemistry 128]

[0222] [Chemistry 129]

[0223] [Chemistry 130]

[0224] [Chemistry 131]

[0225] [Chemistry 132]

[0226] [Chemistry 133]

[0227] [Chemistry 134]

[0228] [Chemistry 135]

[0229] [Chemistry 136]

[0230] [Chemistry 137]

[0231] [Chemistry 138]

[0232] [Chemistry 139]

[0233] [Chemistry 140]

[0234] Specific examples of anions in the repeating unit B10 can be listed below, but are not limited to these. Furthermore, in the following formula, RA is the same as described above. [Chemistry 141]

[0235] In formulas (B7) to (B10), A+ is an onium cation. The aforementioned onium cation is preferably a strontium cation represented by formula (Z-1) or a monium cation represented by formula (Z-2). [Chemistry 142]

[0236] In formulas (Z-1) and (Z-2), Rct1 to Rct5 are halogen atoms or hydrocarbon groups with 1 to 30 carbon atoms that may contain heteroatoms.

[0237] Specific examples of halogen atoms represented by Rct1~Rct5 include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0238] The hydrocarbon groups represented by Rct1 to Rct5 can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, and tertiary butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, which should preferably be aryl. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0239] Furthermore, Rct1 and Rct2 can also bond to each other and form a ring together with the sulfur atoms they are bonded to. Specific examples of the aforementioned ring structures can be shown in the following formulas, etc. [Chemistry 143] In the formula, the dashed lines represent the atomic bonds between Rct3 and Rct3.

[0240] Specific examples of strontium cations represented by formula (Z-1) can be listed, such as those described in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, and those described in paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, but are not limited thereto.

[0241] Specific examples of citric acid represented by formula (Z-2) can be found in paragraph

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

[0242] The Z+ cation of onium should also be represented by the following formula (Z-3) cation of strontium. [Chemistry 144]

[0243] In formula (Z-3), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with m1 = 0. m2 is 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with m2 = 0. m3 is 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. Considering solvent solubility, it is preferable to have a benzene ring with m3 = 0.

[0244] In formula (Z-3), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the solvent solubility will become poor and there is a concern about precipitation in the inhibitor composition. Therefore, m4 should be 0, 1, 2, or 3, with 0, 1, or 2 being better.

[0245] In formula (Z-3), m5 can be 0, 1, 2, 3, or 4. Considering the availability of raw materials, m5 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. m6 can be 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m6 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being more preferred. m7 can be 0, 1, 2, 3, 4, 5, or 6. Considering the availability of raw materials, m7 should preferably be 0, 1, 2, or 3, with 0, 1, or 2 being more preferred.

[0246] In formula (Z-3), m8 is 0, 1, or 2. Considering the availability of raw materials, m8 should ideally be 0 or 1. m9 is 0, 1, or 2. Considering the availability of raw materials, m9 should ideally be 0 or 1. m10 is 0, 1, or 2. Considering the availability of raw materials, m10 should ideally be 0 or 1.

[0247] In formula (Z-3), m11 is 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. Considering the solubility of the solvent, it is preferable to have a benzene ring with m11 of 0.

[0248] In formula (Z-3), m12 is 0, 1, 2, 3 or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the solvent solubility will become poor and there is a concern about precipitation in the inhibitor composition. Therefore, m12 should be 0, 1, 2 or 3, with 0, 1 or 2 being better.

[0249] In formula (Z-3), m13 is 0, 1, or 2. From the perspective of raw material acquisition, m13 should preferably be 0 or 1. m14 is 0, 1, or 2. From the perspective of synthesis, m14 should preferably be 0 or 1.

[0250] However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4; when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4; when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4; when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0251] In formula (Z-3), RF1 to RF3 are independently fluorine atoms, fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms, fluorinated saturated hydrocarbon oxy groups with 1 to 6 carbon atoms, or fluorinated saturated hydrocarbon thio groups with 1 to 6 carbon atoms. Among them, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are preferred. When m5 is 2 or more, each RF1 can be the same or different from each other; when m6 is 2 or more, each RF2 can be the same or different from each other; when m7 is 2 or more, each RF3 can be the same or different from each other.

[0252] In formula (Z-3), Rct6 to Rct9 can be halogen atoms other than iodine and fluorine atoms, nitro, cyano, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. The hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon thio group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given as those illustrated in the description of formula (A) where the hydrocarbon group is represented by R1. Furthermore, some or all of the hydrogen atoms in the hydrocarbon group, hydrocarbon oxygen group, and hydrocarbon sulfur group can be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and halogen atom. Also, some of the -CH2- group in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atom, sulfur atom, and nitrogen atom. As a result, it can also contain hydroxyl group, cyano group, fluorine atom, chlorine atom, bromine atom, iodine atom, carbonyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulfonolactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl group, etc.

[0253] Furthermore, when m8 is 2, the two Rct6 atoms can be identical or dissimilar, 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 Rct7 atoms can be identical or dissimilar, 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 Rct8 atoms can be identical or dissimilar, 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 Rct9 atoms can be identical or dissimilar, 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, norbornene rings, adamantane rings, etc. 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, and some of the -CH2- in the aforementioned ring can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, 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.

[0254] Furthermore, the aromatic rings of S+ directly bonded to the strontium cation, as represented by formula (Z-3), can also bond to each other and form a ring together with S+. Specific examples of the aforementioned ring structures can be listed below. [Chemistry 145] In the formula, the dashed lines represent atomic bonds.

[0255] In formula (Z-3), LB and LC are independently single bonds, ether bonds, ester bonds, amide bonds, sulfonate bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Among them, LB is preferably a single bond, ether bond, ester bond, or sulfonate bond, with ester bonds or sulfonate bonds being more preferred. LC is preferably a single bond, ether bond, or ester bond, with single bonds being more preferred.

[0256] In formula (Z-3), XL is a single bond, or may contain a heteroatom with 1 to 40 carbon atoms in an extended hydrocarbon group. The aforementioned extended hydrocarbon group can be linear, branched, or cyclic; specific examples include: alkyldiyl, cyclic saturated extended hydrocarbon group, extended aryl, etc. Specific examples of the aforementioned heteroatom include: oxygen atom, nitrogen atom, sulfur atom, etc.

[0257] XL can also contain heteroatoms with carbon atoms of 1 to 40, and specific examples are shown below, but are not limited to these. Additionally, in the following formula, * indicates atomic bonds with LB and LC, respectively. [Chemistry 146]

[0258] [Chemistry 147]

[0259] [Chemistry 148]

[0260] [Chemistry 149]

[0261] Among them, the most suitable are XL-0~XL-22, XL-29~XL-34, and XL-47~XL-58.

[0262] The strontium cation represented by formula (Z-3) should preferably be represented by the following formula (Z-3-1). [Chemistry 150] In the formula, m4~m10, m12~m14, RF1~RF3, Rct6~Rct9, LB, LC and XL are the same as those mentioned above.

[0263] The strontium cation represented by formula (Z-3-1) should preferably be represented by formula (Z-3-2). [Chemistry 151] In the formula, m4~m10, RF1~RF3 and Rct6~Rct8 are the same as those mentioned above.

[0264] Specific examples of strontium cations represented by formula (Z-3) are shown below, but are not limited thereto. Additionally, in the following formula, Me is a methyl group. [Chemistry 152]

[0265] [Chemistry 153]

[0266] [Chemistry 154]

[0267] [Chemistry 155]

[0268] [Chemistry 156]

[0269] [Chemistry 157]

[0270] [Chemistry 158]

[0271] [Chemistry 159]

[0272] [Chemistry 160]

[0273] [Chemistry 161]

[0274] [Chemistry 162]

[0275] [Chemistry 163]

[0276] [Chemistry 164]

[0277] [Chemistry 165]

[0278] [Chemistry 166]

[0279] [Chemistry 167]

[0280] [Chemistry 168]

[0281] [Chemistry 169]

[0282] [Chemistry 170]

[0283] [Chemistry 171]

[0284] [Chemistry 172]

[0285] [Chemistry 173]

[0286] [Chemistry 174]

[0287] [Chemistry 175]

[0288] [Chemistry 176]

[0289] [Chemistry 177]

[0290] [Chemistry 178]

[0291] [Chemistry 179]

[0292] The specific structures of repeating units B6 to B10 can be listed as any combination of the aforementioned anions and cations.

[0293] Repeating units B6-B10 are units that generate acid due to irradiation with high-energy rays. It is believed that by incorporating these units into the polymer, acid diffusion can be appropriately suppressed, and a pattern with reduced LER can be obtained. Furthermore, it is believed that by incorporating these units into the polymer, the phenomenon of acid evaporating from the exposed areas and re-adhering to the unexposed areas during vacuum baking can be suppressed, and it is effective in reducing LER and reducing shape degradation caused by undesirable film loss in the unexposed areas.

[0294] Among the repeating units B6 to B10, considering the ideal units for processing blank photomasks, and taking into account the most suitable aspects of acid strength in inhibiting acid diffusion and designing acid-instable groups in polymers, repeating units B7 to B10 are preferable, with repeating units B8, B9, and B10 being even better.

[0295] The repeating units B6 to B10 are preferably introduced in the range of 0.1 to 30 mol%, and more preferably in the range of 0.5 to 20 mol%, in all repeating units of the aforementioned polymer. Repeating units B6 to B10 can be used alone or in combination of two or more.

[0296] In all repeating units of the aforementioned polymer, the content of repeating units having an aromatic ring skeleton is preferably 65 mol% or more, more preferably 75 mol% or more, and even more preferably 85 mol% or more. When repeating units B6 to B10 are not included, it is preferable that all units have an aromatic ring skeleton.

[0297] The aforementioned polymers may also contain commonly used (meth)acrylate units protected by acid-labile groups, or (meth)acrylate units with close-knit groups such as lactone structures or hydroxyl groups other than phenolic hydroxyl groups. These repeating units can be used to fine-tune the properties of the resist film, but they may also be omitted.

[0298] Examples of the aforementioned (meth)acrylate units with adhesive groups include: repeating units represented by formula (B11) (hereinafter also referred to as repeating unit B11), repeating units represented by formula (B12) (hereinafter also referred to as repeating unit B12), and repeating units represented by formula (B13) (hereinafter also referred to as repeating unit B13). These units do not exhibit acidity and can be used auxiliaryly as units to provide adhesion to the substrate and to adjust solubility. [Chemistry 180]

[0299] In formulas (B11) to (B13), RA is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R51 is -O- or a methylene group. R52 is a hydrogen atom or a hydroxyl group. R53 is a saturated hydrocarbon group with 1 to 4 carbon atoms. i is 0, 1, 2, or 3.

[0300] When the polymer contains repeating units B11 to B13, their content should preferably be 0 to 20 mol% or more preferably 0 to 10 mol% of all repeating units in the aforementioned polymer. Repeating units B11 to B13 can be used alone or in combination of two or more.

[0301] The aforementioned polymers can be synthesized by copolymerizing monomers with protecting groups as needed using known methods, followed by deprotection reactions as required. There are no particular limitations on the copolymerization reaction; free radical polymerization and anionic polymerization are preferred. These methods can be referenced in Japanese Patent Application Publication No. 2004-115630.

[0302] The weight-average molecular weight (Mw) of the aforementioned polymer is preferably between 1,000 and 50,000, and more preferably between 2,000 and 20,000. If Mw is above 1,000, there is no concern about the formation of rounded pattern heads leading to reduced resolution, or LER degradation, as is common in conventional methods. On the other hand, if Mw is below 50,000, there is no concern about LER degradation, especially when forming patterns with linewidths below 100 nm. Furthermore, in this invention, Mw is a polystyrene conversion value determined using gel permeation chromatography (GPC) with THF or DMF as solvents.

[0303] The molecular weight distribution (Mw / Mn) of the aforementioned polymer is 1.0~2.0, preferably 1.0~1.9, and a narrow dispersion of 1.0~1.8 is even better. With such a narrow dispersion, foreign matter will not be generated on the pattern after development, or the pattern shape will not be deteriorated.

[0304] Furthermore, regarding the aforementioned basic polymer design, the dissolution rate of the alkaline developer should ideally be below 10 nm / min, preferably below 7 nm / min, and even better below 5 nm / min. In advanced generations, when the coating film applied to the substrate is in the thin film field (below 100 nm), the impact on pattern film loss during alkaline development becomes greater. When the alkaline dissolution rate of the polymer exceeds 10 nm / min, the pattern will break down, making it impossible to form fine patterns. This is especially noticeable in the fabrication of photomasks requiring defect-free results, where there is a tendency for stronger development processes. Furthermore, in this invention, the dissolution rate of the base polymer to the alkaline developer is calculated from the film loss obtained by spin-coating a polymer solution (polymer concentration: 16.7% by mass, solvent: propylene glycol monomethyl ether acetate (PGMEA)) onto an 8-inch silicon wafer, baking it at 100°C for 90 seconds to form a film with a thickness of 1000 nm, and then developing it at 23°C for 100 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.

[0305] (B) The base polymer of the component may also contain other polymers besides those mentioned above. Other polymers may be base polymers commonly used as inhibitor components. There are no particular limitations on the content of other polymers as long as they do not impair the effects of the present invention.

[0306] [(C) Organic solvent] The inhibitor composition of the present invention may also contain an organic solvent as component (C). There are no particular limitations as long as the aforementioned organic solvent is capable of dissolving each component. Examples of such organic solvents include, for instance, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

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

[0307] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and their mixed solvents are preferred.

[0308] When the chemical amplification positive inhibitor composition of the present invention contains (C) organic solvent, its content relative to 80 parts by mass of (B) base polymer is preferably 200-10000 parts by mass, and more preferably 400-5000 parts by mass. (C) organic solvent can be used alone or in combination of two or more.

[0309] [(D) Photoacid generator] The chemical amplification positive inhibitor composition of this invention may also contain a photoacid generator as component (D). There are no particular limitations on the aforementioned photoacid generator, which is a compound that produces acid upon irradiation by high-energy rays. Ideal photoacid generators include: strontium salts, ferrous salts, sulfonyldiazomethane, N-sulfonoxyimide, oxime-O-sulfonate type acid generators, etc.

[0310] Specific examples of the aforementioned photoacid generators include: nonafluorobutane sulfonate, partially fluorinated sulfonates described in paragraphs

[0247] to

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

[0261] to

[0265] of Japanese Patent Application Publication No. 2008-111103, and those described in paragraphs

[0080] to

[0081] of Japanese Patent Application Publication No. 2010-215608. Among the aforementioned specific examples, the aromatic sulfonate type or alkane sulfonate type photoacid generators are more ideal because they produce an acid of appropriate strength when the acid unstable group of the repeating unit B2 is deprotected.

[0311] Such photoacid generators should preferably be salt compounds containing anions as shown below. [Chemistry 181]

[0312] [Chemistry 182]

[0313] [Chemistry 183]

[0314] [Chemistry 184]

[0315] [Chemistry 185]

[0316] [Chemistry 186]

[0317] [Chemistry 187]

[0318] [Chem.188]

[0319] [Chemistry 189]

[0320] [Chemistry 190]

[0321] [Chemistry 191]

[0322] [Chemistry 192]

[0323] [Chemistry 193]

[0324] [Chemistry 194]

[0325] [Chemistry 195]

[0326] [Chemistry 196]

[0327] [Chemistry 197]

[0328] [Chemistry 198]

[0329] [Chemistry 199]

[0330] [Chemistry 200]

[0331] [Chemical Engineering 201]

[0332] [Chemical Engineering 202]

[0333] [Chemical Engineering 203]

[0334] [Chemical 204]

[0335] [Chemical Engineering 205]

[0336] [Chemical Engineering 206]

[0337] [Chemical 207]

[0338] [Chemical Engineering 208]

[0339] [Chemical Engineering 209]

[0340] [Chemical 210]

[0341] [Chemistry 211]

[0342] [Chemistry 212]

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[0345] [Chemical 215]

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[0347] [Chemistry 217]

[0348] [Chemistry 218]

[0349] [Chemistry 219]

[0350] [Chem.220]

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[0352] [Chemistry 222]

[0353] [Chemistry 223]

[0354] [Chemistry 224]

[0355] [Chemistry 225]

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[0357] [Chemistry 227]

[0358] [Chemistry 228]

[0359] [Chemistry 229]

[0360] [Chemistry 230]

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[0363] [Chemistry 233]

[0364] [Chemistry 234]

[0365] [Chemistry 235]

[0366] [Chemistry 236]

[0367] [Chemistry 237]

[0368] [Chemistry 238]

[0369] [Chemistry 239]

[0370] [Chemistry 240]

[0371] [Chemistry 241]

[0372] [Chemistry 242]

[0373] [Chemistry 243]

[0374] [Chemistry 244]

[0375] [Chemistry 245]

[0376] [Chemistry 246]

[0377] [Chemistry 247]

[0378] [Chemistry 248]

[0379] [Chemistry 249]

[0380] [Chemistry 250]

[0381] [Chemistry 251]

[0382] [Chemistry 252]

[0383] [Chemistry 253]

[0384] [Chemistry 254]

[0385] [Chemistry 255]

[0386] [Chemistry 256]

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[0426] [Chemistry 296]

[0427] [Chemistry 297]

[0428] [Chemistry 298]

[0429] [Chemistry 299]

[0430] [Chemical 300]

[0431] [Chemical Engineering 301]

[0432] [Chemical 302]

[0433] [Chemical 303]

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[0466] [Chemistry 336]

[0467] [Chemistry 337]

[0468] [Chemistry 338]

[0469] [Chemistry 339]

[0470] [Transformation 340]

[0471] [Chemistry 341]

[0472] [Chemistry 342]

[0473] [Chemistry 343]

[0474] [Chemistry 344]

[0475] [Chemistry 345]

[0476] [Chemistry 346]

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[0489] [Chemistry 359]

[0490] [Hua360]

[0491] [Chemistry 361]

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[0493] [Chem.363]

[0494] [Chem.364]

[0495] [Chem365]

[0496] [Chemical 366]

[0497] [Chemical 367]

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[0500] [Chemical 370]

[0501] [Chemical 371]

[0502] [Chemical 372]

[0503] [Chemical 373]

[0504] [Chemical 374]

[0505] [Chemical 375]

[0506] [Chemical 376]

[0507] [Chemical 377]

[0508] [Chemical 378]

[0509] [Chemistry 379]

[0510] [Chemistry 380]

[0511] [Chemistry 381]

[0512] [Chemistry 382]

[0513] [Chemistry 383]

[0514] [Chem. 384]

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[0516] [Chemistry 386]

[0517] [Chemistry 387]

[0518] [Chem.388]

[0519] [Chemistry 389]

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[0521] [Chemistry 391]

[0522] [Chemistry 392]

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[0527] [Chemistry 397]

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[0529] [Chemistry 399]

[0530] [Chemical 400]

[0531] [Chemical Engineering 401]

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[0540] [Chemical 410]

[0541] [Chemistry 411]

[0542] [Chemistry 412]

[0543] [Chemistry 413]

[0544] [Chemistry 414]

[0545] [Chemical 415]

[0546] [Chemistry 416]

[0547] [Chemistry 417]

[0548] [Chemistry 418]

[0549] [Chemistry 419]

[0550] [Chem.420]

[0551] [Chemistry 421]

[0552] [Chemistry 422]

[0553] Furthermore, the aforementioned photoacid generator should also be a salt compound containing an anion represented by the following formula (D1). [Chemistry 423]

[0554] In equation (D1), p1 is 1, 2, or 3. p2 is 1, 2, 3, 4, or 5. p3 is 0, 1, 2, or 3. However, 1 ≤ p2 + p3 ≤ 5. q1 is 0 or 1.

[0555] In formula (D1), L21 is a single bond, ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond.

[0556] In formula (D1), L22 is an ether bond, ester bond, sulfonate bond, carbonate bond or carbamate bond.

[0557] In formula (D1), LD is a single bond or an extended hydrocarbon group with 1 to 20 carbon atoms when p1 is 1, and a (p1+1) valence hydrocarbon group with 1 to 20 carbon atoms when p1 is 2 or 3. The extended hydrocarbon group and the (p1+1) valence hydrocarbon group may also contain at least one of the following: ether bond, carbonyl group, ester bond, amide bond, sulfonyl lactone ring, amide ring, carbonate bond, halogen atom, hydroxyl group and carboxyl group.

[0558] LD indicates that the hydrocarbon group with 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl diyl groups with 1 to 20 carbon atoms, such as methane-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 them. Furthermore, the (p1+1) valence hydrocarbon group represented by LD with 1 to 20 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be given by further removing one or two hydrogen atoms from the aforementioned examples of hydrocarbon groups with 1 to 20 carbon atoms.

[0559] In formula (D1), Rf21 and Rf22 are independently hydrogen atoms, fluorine atoms or trifluoromethyl atoms, but at least one of them is a fluorine atom or a trifluoromethyl atom.

[0560] In formula (D1), R101 is a hydroxyl group, a carboxyl group, a saturated hydrocarbon group with 1 to 6 carbon atoms, a saturated hydrocarbon group with 1 to 6 carbon atoms, a saturated hydrocarbon group with 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, -N(R101A)(R101B), -N(R101C)-C(=O)-R101D or -N(R101C)-C(=O)-O-R101D. R101A and R101B are each independently a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R101C is a hydrogen atom or a saturated hydrocarbon group with 1 to 6 carbon atoms. R101D is a saturated hydrocarbon group with 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group with 2 to 8 carbon atoms.

[0561] R101, R101A, R101B, and R101C 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, secondary butyl, tertiary butyl, n-pentyl, and n-hexyl; and cyclic saturated hydrocarbon groups with 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Furthermore, the saturated hydrocarbon base of the saturated hydrocarbon group with 1 to 6 carbon atoms represented by R101 can be the same as the specific examples of the aforementioned saturated hydrocarbon groups. The saturated hydrocarbon base of the carbonyl group with 2 to 6 carbon atoms represented by R101 can be those with 1 to 5 carbon atoms from the specific examples of the aforementioned saturated hydrocarbon groups with 1 to 6 carbon atoms.

[0562] R101D 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, propynyl, 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.

[0563] In formula (D1), R102 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.

[0564] R102 represents an extended hydrocarbon group with 1 to 20 carbon atoms, which can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be listed and illustrated as well as examples of extended hydrocarbon groups with 1 to 20 carbon atoms represented by LB.

[0565] Examples of aryl groups with 6-20 carbon atoms represented by R102 include: phenyl, naphthyl, phenanthrenediyl, anthracenediyl, etc. The substituents of the aforementioned aryl groups are either saturated hydrocarbon groups with 1-20 carbon atoms or hydrocarbon groups with 1-20 carbon atoms whose hydrocarbon base can be straight-chain, branched, or cyclic. Specific examples include: alkyl groups with 1-20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl, tributyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, etc.; and cyclic saturated hydrocarbon groups with 3-20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, adamantyl, etc. Specific examples of the substituents of the aforementioned aryl group, namely aryl groups with 6 to 14 carbon atoms, include: arylphenyl, arylnaphthyl, phenanthrenediyl, anthracenediyl, etc.

[0566] The anion represented by formula (D1) should preferably be the anion represented by formula (D2). [Chemistry 424]

[0567] In formula (D2), p1, p2, p3, L21, LD, and R101 are the same as described above. q2 is 1, 2, 3, or 4. R102A 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 q2 is 2, 3, or 4, each R102A can be the same or different.

[0568] Specific examples of anions represented by formula (D1) can be listed below, but are not limited to these. [Chemical 425]

[0569] [Chemistry 426]

[0570] [Chemistry 427]

[0571] [Chemistry 428]

[0572] [Chemistry 429]

[0573] [Chemistry 430]

[0574] [Chemistry 431]

[0575] [Chemistry 432]

[0576] [Chemistry 433]

[0577] [Chemistry 434]

[0578] [Chemistry 435]

[0579] [Chemistry 436]

[0580] [Chemistry 437]

[0581] [Chemistry 438]

[0582] [Chemistry 439]

[0583] [Chemistry 440]

[0584] [Chemistry 441]

[0585] [Chemistry 442]

[0586] [Chemistry 443]

[0587] [Chemistry 444]

[0588] [Chemistry 445]

[0589] [Chemistry 446]

[0590] [Chemistry 447]

[0591] [Chemistry 448]

[0592] [Chemistry 449]

[0593] [Chemistry 450]

[0594] [Chemistry 451]

[0595] [Chemistry 452]

[0596] [Chemistry 453]

[0597] [Chemistry 454]

[0598] [Chemistry 455]

[0599] [Chemistry 456]

[0600] [Chemistry 457]

[0601] [Chemistry 458]

[0602] [Chemistry 459]

[0603] [Chemistry 460]

[0604] [Chemistry 461]

[0605] (D) In ​​the photoacid generating agent, the cation paired with the aforementioned anion is preferably a strontium cation or a ferrophosphate cation. Specific examples of the aforementioned strontium cation may be listed and illustrated as strontium cations represented by formulas (Z-1) and (Z-3), but are not limited thereto. Specific examples of the aforementioned ferrophosphate cation may be listed and illustrated as ferrophosphate cations represented by formula (Z-2), but are not limited thereto.

[0606] The acid produced by the aforementioned photoacid generator should preferably have a pKa of -2.0 or higher, and preferably -1.0 or higher. Furthermore, the upper limit of the pKa should preferably be 2.0. Additionally, the pKa value was obtained using the pKa DB function in ACD / Chemsketch ver: 9.04, software manufactured by Advanced Chemistry Development, Inc.

[0607] When the chemical amplification positive resist composition of the present invention contains a (D) 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 containing the (D) photoacid generator, the amount of acid generated in the exposed part and the solubility inhibition of the unexposed part can be appropriately adjusted. One type of (D) photoacid generator can be used alone, or two or more types can be used in combination.

[0608] When the chemically amplified positive resist composition of the present invention contains both (D) a photoacid generator and (A) a quencher, the ratio of the photoacid generator to the quencher (photoacid generator / quencher) by mass is preferably less than 3, more preferably less than 2.5, and even more preferably less than 2. If the 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.

[0609] [(E) Polymers containing fluorine atoms] The chemically amplified positive resist composition of this invention, in order to achieve high contrast, suppress the chemical flare phenomenon of acids during high-energy ray irradiation, shield against acid mixing from the antistatic film during the coating of the antistatic film material onto the resist film, and suppress unintended pattern degradation, may also contain a fluorine-containing polymer as component (E). This fluorine-containing polymer contains at least one repeating unit selected from the following formulas: (E1), (E2), (E3), and (E4). The aforementioned fluorine-containing polymer also functions as a surfactant, thus preventing insoluble substances that may be generated during the development process from re-adhering to the substrate, thereby also effectively targeting development defects. [Chemistry 462]

[0610] In formulas (E1) to (E4), k is 1, 2, or 3. RB are independently hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups. R201, R202, R204, and R205 are independently hydrogen atoms or saturated hydrocarbon groups with 1 to 10 carbon atoms. R203, R206, R207, and R208 are independently hydrogen atoms, hydrocarbon groups with 1 to 15 carbon atoms, fluorinated hydrocarbon groups with 1 to 15 carbon atoms, or acid-unstable groups. When R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, ether bonds or carbonyl groups may be inserted between carbon-carbon bonds. Z1 is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms.

[0611] R201, R202, R204, and R205 represent saturated hydrocarbon groups with 1 to 10 carbon atoms, which can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, tertiary butyl, 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.

[0612] R203, R206, R207, and R208 represent hydrocarbon groups with 1 to 15 carbon atoms, which can be linear, 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, preferably alkyl groups with 1 to 15 carbon atoms. The aforementioned alkyl groups can include those listed above, as well as: 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, n-pentadecanyl, etc. Furthermore, fluorinated hydrocarbon groups can be groups formed by replacing one or all of the hydrogen atoms of the carbon atoms bonded to the aforementioned hydrocarbon groups with fluorine atoms.

[0613] Z1 can be represented by (k+1) valence hydrocarbon groups with 1 to 20 carbon atoms, which can be derived from alkyl groups with 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms by further removing k hydrogen atoms. Furthermore, Z1 can be represented by (k+1) valence fluorinated hydrocarbon groups with 1 to 20 carbon atoms, which can be derived from groups where at least one hydrogen atom of the aforementioned (k+1) valence hydrocarbon group is replaced by a fluorine atom.

[0614] Specific examples of repeating units E1 to E4 can be listed below, but are not limited to these. Furthermore, in the following formula, RB is the same as described above. [Chemistry 463]

[0615] [Chemistry 464]

[0616] [Chemistry 465]

[0617] Furthermore, the aforementioned fluorine-containing polymers preferably contain at least one of the repeating units selected from the following formula (E5) (hereinafter also referred to as repeating unit E5) and the following formula (E6) (hereinafter also referred to as repeating unit E6). [Chemistry 466]

[0618] In formulas (E5) and (E6), j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. RC are independently hydrogen atoms or methyl groups. R209 is a hydrogen atom, or a linear or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have a heteroatom-containing group inserted between carbon-carbon bonds. R210 is a linear or branched hydrocarbon group with 1 to 5 carbon atoms, which may also have a heteroatom-containing group 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 aforementioned 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 is a single bond, -O-, *-C(=O)-O-Z31-Z32-, or *-C(=O)-NH-Z31-Z32-. Z31 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms. Z32 is a single bond, ester bond, ether bond, or sulfonamide bond. * represents an atomic bond with a carbon atom in the main chain.

[0619] R209 and R210 can represent hydrocarbon groups with 1 to 5 carbon atoms, including alkyl, alkenyl, and ynyl groups, preferably alkyl. Examples of the aforementioned 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.

[0620] In formula (E5), -OR209 should preferably be a hydrophilic group. In this case, R209 should preferably be a hydrogen atom, or an alkyl group with 1 to 5 carbon atoms with oxygen atoms inserted between carbon-carbon bonds.

[0621] R211 indicates that at least one hydrogen atom is replaced by a fluorine atom to form a saturated hydrocarbon group with 1 to 20 carbon atoms, which 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.

[0622] Z2 should ideally be *-C(=O)-O- or *-C(=O)-NH-. Furthermore, RC should ideally be methyl. The presence of a carbonyl group in Z2 improves the acid capture ability from the antistatic film. Also, if RC is methyl, it becomes a rigid polymer with a higher glass transition temperature (Tg), thus inhibiting acid diffusion. This results in a resistive film with good stability over time, without deterioration in resolution or pattern shape.

[0623] Z3 indicates that the saturated extended hydrocarbon group with 1 to 10 carbon atoms can be any of the following: straight-chain, branched, or cyclic. Specific examples include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, 1,1-dimethylethane-1,2-diyl, etc.

[0624] Repeating unit E5 can be listed as shown below, but is not limited to these. Additionally, in the following formula, RC is the same as described above. [Chemistry 467]

[0625] [Chemistry 468]

[0626] Repeating unit E6 can be listed as shown below, but is not limited to these. Additionally, in the following formula, RC is the same as described above. [Chemistry 469]

[0627] [Chemistry 470]

[0628] [Chemistry 471]

[0629] [Chemistry 472]

[0630] The content of repeating units E1 to E4 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 E5 and / or E6 in the aforementioned polymer containing fluorine atoms is preferably 5 to 85 mol%, and more preferably 15 to 80 mol%. Repeating units E1 to E6 can be used alone or in combination of two or more.

[0631] (E) Polymers containing fluorine atoms may also contain other repeating units besides the aforementioned repeating units. Examples of such repeating units include those described in paragraphs

[0046] to

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

[0632] (E) Polymers containing fluorine atoms can be synthesized by copolymerizing monomers with protecting groups as needed using known methods, followed by deprotection reactions as required. There are no particular limitations on the copolymerization reaction; free radical polymerization and anionic polymerization are preferred. These methods can be referenced in Japanese Patent Application Publication No. 2004-115630.

[0633] (E) The Mw of fluorine-containing polymers should preferably be 2000~50000, and 3000~20000 is more preferred. If Mw is above 2000, acid will not diffuse, resolution will not deteriorate, and stability over time will not be compromised. If Mw is below 50000, solubility in solvents is sufficient, and coating defects will not occur. Furthermore, the Mw / Mn ratio of (E) fluorine-containing polymers should preferably be 1.0~2.2, and 1.0~1.7 is more preferred.

[0634] When the chemical amplification positive inhibitor composition of the present invention contains a (E) fluorine-containing polymer, its content relative to 80 parts by mass of the (B) base polymer is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass. The (E) fluorine-containing polymer can be used alone or in combination of two or more.

[0635] [(F) Other quenching agents] The chemical amplification positive inhibitor composition of the present invention may also contain a quencher other than component (A) (hereinafter also referred to as other quenchers) as component (F) as needed.

[0636] Other quenching agents mentioned above include conventional basic compounds. Conventional basic compounds 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, amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, sulfonate bonds, or compounds having carbamate groups as described in Japanese Patent No. 3790649 are especially preferred. Ideal examples 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, the diffusion rate of acid in the resist film can be further suppressed, or the shape can be modified.

[0637] Furthermore, other quenching agents mentioned above include onium salts such as strontium salts, ferrophosphate salts, and ammonium salts of α-unfluorinated carboxylic acids, as described in Japanese Patent Application Publication No. 2008-158339. α-fluorinated sulfonic acids, amide acids, or methylated acids are necessary for deprotecting unstable acid groups, and through salt exchange with α-unfluorinated onium salts, α-unfluorinated carboxylic acids are released. α-unfluorinated carboxylic acids hardly undergo deprotection reactions, thus functioning as quenching agents.

[0638] Onium salts of unfluorinated carboxylic acids at the α-position can be represented by, for example, those indicated by the following formula (F1). [Chemistry 473]

[0639] In formula (F1), R301 is a hydrogen atom or a hydrocarbon group with 1 to 40 carbon atoms that may contain heteroatoms, except that the hydrogen atom of the carbon atom bonded to the α position of the carboxyl group is replaced by a fluorine atom or a fluoroalkyl group.

[0640] R301 indicates that the hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: alkyl groups with 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary butyl, tertiary butyl, n-pentyl, tertiary pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclo[5.2.1.02,6]decyl, adamantyl, and adamantylmethyl; and vinyl, allyl, propenyl, butenyl, and hexenyl groups with 2 to 4 carbon atoms. Alkenyl groups with 0 carbon atoms; cyclohexenyl and other cyclic unsaturated aliphatic hydrocarbon groups with 3 to 40 carbon atoms; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tributylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, 2-phenylethyl, etc.

[0641] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- group in the aforementioned hydrocarbon group can also be replaced by a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain 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. Examples of hydrocarbon groups containing heteroatoms 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.

[0642] In formula (F1), MqA+ represents 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 can be listed and illustrated as examples of the strontium cation represented by formula (Z-1) and formula (Z-3). Similarly, specific examples of the aforementioned ferrophosphate cation can be listed and illustrated as examples of the ferrophosphate cation represented by formula (Z-2).

[0643] The anions of onium salts represented by formula (F1) can be listed below, but are not limited to these. [Chemistry 474]

[0644] [Chemistry 475]

[0645] [Chemistry 476]

[0646] The aforementioned quenching agent can also ideally be a strontium salt of a carboxylic acid containing an iodinated benzene ring, represented by the formula (F2). [Chemistry 477]

[0647] In equation (F2), 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.

[0648] In formula (F2), R311 is a 1-6 carbon saturated hydrocarbon group, a 1-6 carbon saturated hydrocarbon oxygen group, a 2-6 carbon saturated hydrocarbon carbonyl oxygen group, or a 1-4 carbon saturated hydrocarbon sulfonyl oxygen group, or -N(R311A)-C(=O)-R311B or -N(R311A)-C(=O)-O-R311B. R311A is a hydrogen atom or a 1-6 carbon saturated hydrocarbon group. R311B is a 1-6 carbon saturated hydrocarbon group or an 2-8 carbon unsaturated aliphatic hydrocarbon group. When t and / or u are 2 or more, each R311 can be the same or different.

[0649] In formula (F2), L21 is a single bond or a (u+1) valent linkage with 1 to 20 carbon atoms, and may also contain at least one of the following: ether bond, carbonyl group, ester bond, amide bond, sulfonyl lactone ring, amide ring, carbonate bond, halogen atom, hydroxyl group, and carboxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic.

[0650] In formula (F2), R312, R313, and R314 are each independently a halogen atom or a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be 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 may be substituted with hydroxyl, carboxyl, halogen, oxy, cyano, nitro, sulfonyl lactone ring, sulfonyl, or strontium-containing groups, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may be substituted with ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Additionally, R312 and R313 may be bonded to each other and form a ring together with the sulfur atoms they are bonded to.

[0651] Specific examples of compounds represented by formula (F2) can be found in Japanese Patent Application Publication No. 2017-219836. Compounds represented by formula (F2) have high sensitization effects due to their high absorption and also have high acid diffusion control effects.

[0652] The aforementioned quenching agent can also be represented by a nitrogen-containing carboxylate compound with the following formula (F3). [Chemistry 478]

[0653] In formula (F3), R321 to R324 are independently hydrogen atoms, -L31-CO2-, or may contain heteroatoms and are hydrocarbon groups with 1 to 20 carbon atoms. R321 and R322, R322 and R323, or R323 and R324 may also bond to each other and form a ring together with the carbon atoms they are bonded to. L31 is a single bond or may contain heteroatoms and are hydrocarbon groups with 1 to 20 carbon atoms. R325 is a hydrogen atom or may contain heteroatoms and are hydrocarbon groups with 1 to 20 carbon atoms.

[0654] In formula (F3), ring Rr is a ring with 2 to 6 carbon atoms, including the carbon and nitrogen atoms in the formula. Part or all of the hydrogen atoms bonded to the carbon atoms in this ring may be replaced by hydrocarbon groups with 1 to 20 carbon atoms, or by -L31-CO2-. Furthermore, a portion of the carbon atoms in this ring may be replaced by sulfur, oxygen, or nitrogen atoms. The aforementioned ring can be an alicyclic or aromatic ring, and preferably a 5- or 6-membered ring. Specific examples include: pyridine ring, pyrrole ring, pyrrolidinium ring, piperidine ring, pyrazole ring, imidazoline ring, pyrazine ring, pyrimidine ring, pyrazine ring, imidazoline ring, pyrazolium ring, thiazole ring, pyrazine ring, thiazoline ring, triazole ring, etc.

[0655] The carboxylic acid salt represented by formula (F3) has at least one -L31-CO2- group. That is, at least one of R321 to R324 is -L31-CO2-, and / or at least one of the hydrogen atoms of the carbon atom bonded to the ring Rr is replaced by -L31-CO2-.

[0656] In formula (F3), MqB+ can be listed as: strontium cation, monium cation, or ammonium cation, preferably strontium cation. Specific examples of the aforementioned strontium cation can be listed and illustrated as specific examples of strontium cations represented by formula (Z-1) and formula (Z-3).

[0657] The anions of compounds represented by formula (F3) can be listed below, but are not limited to these. [Chemistry 479]

[0658] [Chemistry 480]

[0659] [Chemistry 481]

[0660] [Chemistry 482]

[0661] [Chemistry 483]

[0662] [Chemistry 484]

[0663] Furthermore, the aforementioned quenching agents can also be betaine-type compounds of weak acids. Specific examples are listed below, but are not limited to these. [Chemistry 485]

[0664] The aforementioned quenchers can be further exemplified by polymer-type quenchers disclosed in Japanese Patent Application Publication No. 2008-239918. These quenchers enhance the rectangularity of the resist pattern by aligning to the surface of the resist film. Polymer-type quenchers also prevent film loss and dome-shaped formation of the pattern when using protective films for immersion exposure.

[0665] When the chemical amplification positive inhibitor composition of the present invention contains other quenchers (F), their content relative to 80 parts by mass of the aforementioned (B) base polymer is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass. The aforementioned quenchers can be used alone or in combination of two or more.

[0666] (G) Surfactants In order to improve the coating properties of the substrate, the chemically amplified positive resist composition of the present invention may also contain a commonly used surfactant as component (G). Many of the aforementioned surfactants are 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 can be selected by referring to them.

[0667] When the chemically amplified positive inhibitor composition of the present invention contains (G) surfactant, its content relative to 80 parts by mass of (B) base polymer is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and the lower limit is preferably set to 0.01 parts by mass or more. (G) surfactant can be used alone or in combination of two or more.

[0668] [Resistant Pattern Formation Method] The resist pattern forming method of the present invention includes the following steps: A resist film is formed on a substrate using the aforementioned chemically amplified positive resist composition. The aforementioned resist film was exposed using high-energy rays, and The resist pattern is obtained by developing the resist film that has been irradiated with the aforementioned pattern using an alkaline developer.

[0669] The aforementioned substrate can be, for example, substrates used in integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective films, etc.) or substrates used in mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, etc.). The aforementioned chemically amplified positive resist composition is coated onto the aforementioned substrate using methods such as spin coating to achieve a film thickness of 0.03~2 μm. The substrate is then pre-baked on a hot plate, preferably at 60~150°C for 1~20 minutes, and more preferably at 80~140°C for 1~10 minutes, to form a resist film.

[0670] Then, the resist film is exposed to high-energy rays to irradiate the pattern. Examples of such high-energy rays include: ultraviolet rays, far-ultraviolet rays, excimer laser light (KrF, ArF, etc.), EB, EUV, X-rays, gamma rays, synchrotron radiation, etc.

[0671] 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 desired pattern, and irradiation is performed with an exposure dose preferably of 1-300 mJ / cm², and more preferably 10-200 mJ / cm². When using EB lithography for high-energy lithography, the pattern is directly drawn with an exposure dose preferably of 1-300 μC / cm², and more preferably 10-200 μC / cm². Furthermore, the chemically amplified positive resist composition of this invention is particularly useful in EUV or EB lithography.

[0672] In addition to the usual exposure method, the immersion method, in which a liquid is inserted between the mask and the resist film, can also be used, depending on the situation. In this case, a water-insoluble protective film can also be used.

[0673] Then, expose and bake on a heating plate at a temperature of 60-150°C for 1-20 minutes, preferably 80-140°C for 1-10 minutes (PEB).

[0674] Subsequently, a developing solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of 0.1-5% by mass, and more preferably 2-3% by mass, is used to develop the substrate for 0.1-3 minutes, preferably 0.5-2 minutes, using common methods such as dip, immersion, and spray, thereby forming the desired pattern on the substrate.

[0675] The chemically amplified positive resist composition of this invention is useful when particularly high etch resistance is required, and when the pattern linewidth variation and LER remain small even when the time from exposure to PEB is extended. Furthermore, the resist composition of this invention is particularly useful when the surface of the substrate is made of a material that is prone to pattern peeling or pattern breakage due to difficulty in achieving good adhesion of the resist pattern. Examples of such substrates include substrates formed by sputtering metallic chromium or chromium compounds containing one or more light elements selected from oxygen, nitrogen, and carbon. The chemically amplified positive resist composition of this invention is particularly useful for pattern formation using a blank photomask as the substrate. [Example]

[0676] The present invention will be specifically described below with examples of synthesis, embodiments, and comparative examples, but the present invention is not limited to the following embodiments. Furthermore, the apparatus used is described below. MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0677] [1] Synthesis of strontium salts [Example 1-1] Synthesis of strontium salt SQ-1 [Chemistry 486]

[0678] (1) Synthesis of intermediate In-1 Under nitrogen atmosphere, 4-iodophenol (110.0 g), methyl thiosalicylate (92.5 g), and copper iodide (9.5 g) were dissolved in N-methylpyrrolidone (400 g) in a reaction vessel. The temperature inside the reaction vessel was raised to 70°C, and triethylamine (65.8 g) was added dropwise. After the addition, the reaction vessel was heated to 80°C and matured for 12 hours. After maturation, the reaction solution was cooled, and water (300 g) was added to stop the reaction. The target was extracted with toluene (500 g). After extraction, a conventional aqueous work-up was performed, and the solvent was distilled off. The solution was then purified by distillation to obtain 113.2 g of intermediate In-2 (87% yield) as an oil.

[0679] (2) Synthesis of intermediate In-2 Under nitrogen atmosphere, intermediate In-1 (113.2 g), potassium carbonate (72.1 g), and sodium iodide (6.5 g) were dissolved in DMF (400 g) in a reaction vessel. The temperature inside the reaction vessel was raised to 70°C, and 1-bromooctane (100.8 g) was added dropwise. After the addition, the reaction vessel was heated to 80°C and matured for 12 hours. After maturation, the reaction solution was cooled, and water (500 g) was added to stop the reaction. The target was extracted with hexane (500 g). Subsequently, a conventional aqueous work-up was performed, and the solvent was distilled off. The solution was then purified using a silicone column to obtain 153.9 g of intermediate In-2 (95% yield) as an oil.

[0680] (3) Synthesis of intermediate In-3 Under nitrogen atmosphere, intermediate In-2 (37.3 g) and diphenylmonazine methanesulfonate (41.4 g) were dissolved in anisole (150 g) in a reaction vessel. Copper acetate (0.9 g) was then added, and the temperature in the reaction vessel was raised to 100°C for heating and maturation for 12 hours. After maturation, the reaction solution was cooled, and water (200 g) was added to stop the reaction. The target was extracted with dichloromethane (300 g). Subsequently, a standard aqueous work-up was performed, and the solvent was distilled off. The solution was then purified using a silicone column to obtain 47.4 g of intermediate In-3 (87% yield) as an oil.

[0681] (4) Synthesis of strontium salt SQ-1 Under nitrogen atmosphere, intermediate In-3 (16.3 g) was dissolved in methanol (40 g) in a reaction vessel. A 25% (w / w) aqueous solution of sodium hydroxide (5.8 g) was added, and the mixture was allowed to mature for 4 hours. After maturation, water (30 g) was added to stop the reaction, and dichloromethane (80 g) was added to extract the target compound. Subsequently, a standard aqueous work-up was performed, and the solvent was distilled off. The residue was then washed with diisopropyl ether to obtain 11.3 g of the target compound, SQ-1, as an oil (87% yield).

[0682] The TOF-MS results of SQ-1 are shown below. MALDI TOF-MS: POSITIVE M+435 (equivalent to C27H31O3S+)

[0683] [Examples 1-2~1-10] Synthesis of strontium salts SQ-2~SQ-10 Using the corresponding raw materials and known organic synthesis reactions, strontium salts SQ-2 to SQ-10 represented by the following formulas were synthesized. [Chemistry 487]

[0684] [2] Synthesis of basic polymers [Synthetic Example] Synthesis of basic polymers (P-1~P-6) The monomers were combined using a known formulation and copolymerized in a solvent. The reaction solution was then added to hexane, and the precipitated solid was washed with hexane, separated, and dried to obtain the basic polymers (P-1 to P-6) with the compositions shown below. The composition of the obtained basic polymers was confirmed using 1H-NMR and 13C-NMR, and Mw and Mw / Mn were confirmed using GPC (solvent: DMF, standard: polystyrene). [Chemistry 488]

[0685] [3] Preparation of chemically amplified positive inhibitor composition [Examples 2-1 to 2-50, Comparative Examples 1-1 to 1-35] The components were dissolved in an organic solvent according to the compositions shown in Tables 1-3 below, and the resulting solutions were filtered through a 5nm nylon filter and a 1nm UPE filter to obtain a chemically amplified positive inhibitor composition. The aforementioned organic solvent was a mixture of 940 parts by mass of PGMEA, 1870 parts by mass of EL, and 1870 parts by mass of PGME.

[0686] [Table 1]

[0687] [Table 2]

[0688] [Table 3]

[0689] Tables 1-3 describe the photoacid generators PAG-1 to PAG-6, the comparative quenchers SQ-A to SQ-D, and the fluorine-containing polymers FP-1 to FP-5 as follows. [Chemistry 489]

[0690] [Chemistry 490]

[0691] [Chemistry 491]

[0692] [4] EB Microfilm Review [Examples 3-1 to 3-50, Comparative Examples 2-1 to 2-35] Each chemically amplified positive resist composition (R-1~R-50, CR-1~CR-35) was spin-coated onto a 152 mm square EUV exposure mask with a chromium compound outermost surface using an ACT-M spin coater. The mask was then pre-baked at 110°C for 600 seconds on a heated plate to obtain a resist film with a thickness of 80 nm. The film thickness was measured using an optical measuring instrument, NANOSPEC (Nanometrics). Measurements were taken at 81 positions within the plane of the blank substrate, excluding the outer 10 mm from the periphery, to obtain the average film thickness and the film thickness range.

[0693] Then, exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., with an accelerating voltage of 50kV), applying PEB at 110°C for 600 seconds, and developing with a 2.38% by mass TMAH aqueous solution to obtain a positive pattern.

[0694] The obtained resist patterns were evaluated as follows. The prepared blank mask with the pattern was observed using an overhead SEM (scanning electron microscope). The optimal exposure (μC / cm²) was defined as the exposure at which the 1:1 line-to-spacing (LS) at 200 nm was resolved at a 1:1 ratio. The minimum size at this exposure was defined as the resolution (limiting resolution). The LER (Lead Reduction) of the 200 nm LS was then measured using SEM. For the limiting resolution of the isolation spacing (IS), the minimum size at this exposure was defined as the exposure at which the 9:1 line-to-spacing (LS) at 200 nm was resolved at a 9:1 ratio. The shape of the pattern was visually determined to be rectangular. The results are shown in Tables 4-6.

[0695] [Table 4]

[0696] [Table 5]

[0697] [Table 6]

[0698] As shown in Tables 4-6, the chemically amplified positive inhibitor compositions (R-1 to R-50) of the present invention all exhibit good resolution, LER, and pattern rectangularity. On the other hand, the inhibitor compositions of the comparative examples (CR-1 to CR-35) showed insufficient optimization of acid diffusion, and deterioration in resolution, LER, and pattern rectangularity was observed.

[0699] 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 strontium salt, represented by the following formula (A); wherein n1 is 0 or 1; n2 is 0, 1, 2, 3 or 4; n3 is 0 or 1; n4 is 0 or 1; LA is a single bond, ether bond, ester bond or sulfonate bond; Ralk is an alkyl group having 6 to 18 carbon atoms or a fluorinated alkyl group having 4 to 18 carbon atoms; when Ralk is an alkyl group having 6 to 18 carbon atoms, the alkyl group has at least one straight-chain structure having 6 or more carbon atoms; when Ralk is a fluorinated alkyl group having 4 to 18 carbon atoms, the fluorinated alkyl group has at least two groups selected from -CF2- and -CF3; furthermore, a portion of the -CH2- group of the alkyl group and the fluorinated alkyl group may also be substituted by an ether bond or a carbonyl group; Ra is an aryl group with 6 to 30 carbon atoms or an aralkyl group with 7 to 30 carbon atoms. Some or all of the hydrogen atoms of the aryl group or aralkyl group may be substituted with a group containing heteroatoms. Also, Ra and two of the two aromatic rings bonded to S+ in the formula may bond to each other and form a ring together with the sulfur atoms they are bonded to. R1 is a halogen atom, nitro group, cyano group, hydroxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms containing heteroatoms. When n2 is 2, 3 or 4, each R1 may be the same or different from the others, and multiple R1s may bond to each other and form a ring together with the carbon atoms they are bonded to. R2 can be a halogen atom, nitro, cyano, hydroxyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, or a hydrocarbon thio group with 1 to 20 carbon atoms; when n4 is 2, 3, or 4, each R2 can be the same or different, and multiple R2s can also bond to each other and form a ring together with the carbon atoms they are bonded to.

2. The strontium salt of claim 1 is represented by the following formula (A1); where n1~n4, LA, Ralk, Ra, R1 and R2 are the same as those in claim 1; n5 is 0 or 1; n6 is 0, 1, 2, 3 or 4; R3 is a halogen atom, nitro, cyano, hydroxyl, or may contain a hydrocarbon group with 1 to 20 carbon atoms of heteroatoms, or a hydrocarbon oxy group with 1 to 20 carbon atoms of heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms of heteroatoms; when n6 is 2, 3 or 4, each R3 may be the same or different from each other, and multiple R3s may also bond to each other and form a ring together with the carbon atoms they are bonded to.

3. The strontium salt of claim 2 is represented by the following formula (A2); where n2, n4, n6, LA, Ralk, Ra, R1, R2 and R3 are the same as those in claim 2.

4. A quenching agent comprising a strontium salt as claimed in claim 1.

5. A chemical amplification positive inhibitor composition comprising a quencher as claimed in claim 4.

6. The chemical amplification positive inhibitor composition of claim 5 further contains a base polymer that decomposes due to the action of acid and increases the solubility of the polymer in alkaline developer.

7. The chemical amplification positive inhibitor composition as described in claim 6, wherein, The polymer contains repeating units represented by the following formula (B1); where 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 is a halogen atom, a nitro group, a carboxyl group, a 1-6 carbon saturated hydrocarbon group that may be substituted by a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that may be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that may be substituted by a halogen atom; A1 is a single bond or a 1-10 carbon saturated hydrocarbon group, and a portion of the -CH2- of the saturated hydrocarbon group may also be substituted by -O-.

8. The chemical amplification positive inhibitor composition as claimed in claim 6, wherein, The polymer contains repeating units represented by the following formula (B2-1); where RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; b1 is 0 or 1; b2 is 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; R21 is a halogen atom, a 1-6 carbon saturated hydrocarbon group that may be substituted by a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that may be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that may be substituted by a halogen atom; A2 is a single bond or a 1-10 carbon saturated hydrocarbon group, and part of the -CH2- of the saturated hydrocarbon group may also be substituted by -O-; X is an acid-unstable group when b4 is 1, and a hydrogen atom or an acid-unstable group when b4 is 2 or 3, but at least one is an acid-unstable group.

9. The chemical amplification positive inhibitor composition as claimed in claim 6, wherein, The polymer contains repeating units represented by the following formula (B2-2); where 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; RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; R22 and R23 are each independently a hydrocarbon group having 1 to 10 carbon atoms, and may also contain heteroatoms, and R22 and R23 may also be bonded to each other and form a ring together with the carbon atoms they are bonded to; R24 are each independently a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorinated alkoxy group having 1 to 5 carbon atoms; R25 are each independently a hydrocarbon group having 1 to 10 carbon atoms, and may also contain heteroatoms. A3 is a single bond, phenyl, naphthyl, or *-C(=O)-O-A31-; A31 may also contain a hydroxyl group, ether bond, ester bond, or lactone ring with 1 to 20 carbon atoms, an aliphatic alkyl group, or phenyl or naphthyl; * is an atomic bond with a carbon atom of the main chain.

10. The chemical amplification positive inhibitor composition as claimed in claim 6, wherein, The polymer contains at least one repeating unit selected from the following formula (B3), the following formula (B4), and the following formula (B5); wherein d is 0, 1, 2, 3, 4, 5, or 6; e is 0, 1, 2, 3, or 4; f1 is 0 or 1; f2 is 0, 1, or 2; f3 is 0, 1, 2, 3, 4, or 5; RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; R31 and R32 are independently a hydroxyl group, a halogen atom, a 1-6 carbon saturated hydrocarbon group that may be substituted by a halogen atom, a 1-6 carbon saturated hydrocarbon oxygen group that may be substituted by a halogen atom, or a 2-8 carbon saturated hydrocarbon carbonyl oxygen group that may be substituted by a halogen atom. R33 is a saturated hydrocarbon group with 1 to 20 carbon atoms, a saturated hydrocarbon oxy group with 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms, a saturated hydrocarbon oxy hydrocarbon group with 2 to 20 carbon atoms, a saturated hydrocarbon thioalkyl hydrocarbon group with 2 to 20 carbon atoms, a halogen atom, a nitro group, or a cyano group, and f2 can also be a hydroxyl group when it is 1 or 2; A4 is a single bond or a saturated hydrocarbon group with 1 to 10 carbon atoms, and part of the -CH2- of the saturated hydrocarbon group can also be replaced by -O-.

11. The chemical amplification positive inhibitor composition as claimed in claim 6, wherein, The polymer contains at least one repeating unit selected from the following formulas (B6, B7, B8, B9, and B10); wherein g1 and g2 are independently 0, 1, 2, or 3; h1 is 0 or 1; h2 is 0, 1, 2, 3, or 4; h3 is 0, 1, 2, 3, or 4; however, when h1 is 0, 0 ≤ h2 + h3 ≤ 4, and when h1 is 1, 0 ≤ h2 + h3 ≤ 6; RA are independently hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; Z1 is a single bond or may also have substituents, such as phenyl groups; Z2 is a single bond, **-C(=O)-O-Z21-, **-C(=O)-NH-Z21-, or **-O-Z21-; Z21 is an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, or a divalent group obtained by combining them, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z3 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond, or a carbamate bond; Z4 is a single bond, or an aliphatic alkyl group with 1 to 6 carbon atoms, an alkyl phenyl group, or a divalent group obtained by combining them, and may also contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z5 is independently a single bond, or may contain substituents such as phenyl, naphthyl, or *-C(=O)-O-Z51-; Z51 is an aliphatic alkyl group, phenyl, or naphthyl with 1 to 10 carbon atoms, and the aliphatic alkyl group may also contain halogen atoms, hydroxyl groups, ether bonds, ester bonds, or lactone rings; Z6 is a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; Z7 is independently a single bond, ***-Z71-C(=O)-O-, ***-C(=O)-NH-Z71-, or ***-O-Z71-; Z71 may also contain heteroatoms and is an alkyl group with 1 to 20 carbon atoms; Z8 can be a single bond, ****-Z81-C(=O)-O-, ****-C(=O)-NH-Z81-, or ****-O-Z81-; Z81 can be a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms; Z9 can be a single bond, methylene, ethyl, phenyl, fluorinated phenyl, phenyl substituted with trifluoromethyl, *-C(=O)-O-Z91-, *-C(=O)-N(H)-Z91-, or *-O-Z91-; Z91 can be an aliphatic hydrocarbon group with 1 to 6 carbon atoms, phenyl, fluorinated phenyl, or phenyl substituted with trifluoromethyl, and may also contain carbonyl, ester, ether, or hydroxyl groups; * indicates an atomic bond with the carbon atom of the main chain; ** indicates an atomic bond with Z1; *** indicates an atomic bond with Z6; **** indicates an atomic bond with Z7; L1 can be a single bond, ether bond, ester bond, carbonyl group, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; Rf1 and Rf2 can be independently fluorine atoms or fluorinated saturated hydrocarbon groups with 1 to 6 carbon atoms;Rf3 and Rf4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; Rf5 and Rf6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; however, not all Rf5 and Rf6 are simultaneously hydrogen atoms; Rf7 is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkyl thio group having 1 to 6 carbon atoms; R41 and R42 are each independently a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms; furthermore, R41 and R42 may also bond to each other and form a ring together with the sulfur atoms they are bonded to; R43 is a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms, which may also contain heteroatoms; when h3 is 2, 3, or 4, each R43 may be the same or different from the others, and multiple R43 may also bond to each other and form a ring together with the carbon atoms they are bonded to; M- is a non-nucleophilic relative ion; A+ is an onium cation.

12. The chemical amplification positive inhibitor composition as claimed in claim 6, wherein, Of all the repeating units in the base polymer, the content of repeating units with an aromatic ring skeleton is 60 mol% or more.

13. The chemical amplification positive inhibitor composition of claim 5 further contains organic solvents.

14. The chemical amplification positive inhibitor composition of claim 5 further contains a photoacid generator.

15. The chemical amplification positive inhibitor composition of claim 5 further contains at least one repeating unit selected from the following formula (E1), the following formula (E2), the following formula (E3), and the following formula (E4), and may further contain a fluorine-containing polymer selected from the following formula (E5) and the following formula (E6); wherein, j1 is 1, 2, or 3; j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1; j3 is 0 or 1; k is 1, 2, or 3; RB are independently hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; RC are independently hydrogen atoms or methyl groups; R201, R202, R204, and R205 are independently hydrogen atoms or saturated hydrocarbon groups having 1 to 10 carbon atoms; R203, R206, R207, and R208 are, independently, hydrogen atoms, hydrocarbon groups with 1 to 15 carbon atoms, fluorinated hydrocarbon groups with 1 to 15 carbon atoms, or acid-unstable groups. When R203, R206, R207, and R208 are hydrocarbon groups or fluorinated hydrocarbon groups, ether bonds or carbonyl groups may be inserted between carbon-carbon bonds. R209 is a hydrogen atom, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms that may have a heteroatom inserted between carbon-carbon bonds. R210 is a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms that may have a heteroatom 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. Z1 is a (k+1) valence hydrocarbon group with 1 to 20 carbon atoms or a (k+1) valence fluorinated hydrocarbon group with 1 to 20 carbon atoms; Z2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * is an atomic bond with a carbon atom in the main chain; 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 hydrocarbon 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.

16. The chemical amplification positive inhibitor composition of claim 5 further contains a quencher other than the quencher of claim 4.

17. 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 5 to 16, irradiating the resist film with a pattern using high-energy rays, and developing the irradiated resist film with an alkaline developer.

18. The method for forming a resist pattern as described in claim 17, wherein, The high-energy rays are extreme ultraviolet rays or electron beams with wavelengths of 3 to 15 nm.

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

20. The method for forming a resist pattern as described in claim 17, wherein, The substrate is a blank photomask.