Resist composition and pattern forming method

Abstract

The invention relates to a resist composition and a pattern forming method. The present invention addresses the problem of providing a non-chemically amplified resist composition having excellent sensitivity and limit resolution in optical lithography using high-energy rays, and a pattern forming method using the resist composition. The resist composition contains at least one type of hypervalent iodine compound represented by any one of formulae (1) to (4), a predetermined onium salt compound, a carboxyl group-containing compound, and a solvent.

Description

TECHNICAL FIELD

[0001] The present application relates to a resist composition and a pattern forming method. BACKGROUND

[0002] With the expansion of the IoT market, further demands are made for high integration, high speed, and low power consumption of LSIs, and the miniaturization of pattern rules is also rapidly progressing. In particular, logic devices are leading the miniaturization. As for the most advanced miniaturization technology, mass production of 10-nm-node devices obtained by double patterning, triple patterning, and quadruple patterning of ArF immersion lithography is underway, and in addition, the exploration of 7-nm-node devices obtained by extreme ultraviolet (EUV) lithography of the next generation wavelength of 13.5 nm is progressing.

[0003] With the progress of miniaturization, blurring of images due to diffusion of acid also becomes a problem (Non-Patent Literature 1). In order to ensure the resolution of fine patterns of 45 nm or less in processing size, it has been proposed that not only the improvement of the dissolution contrast conventionally advocated is important, but also the control of acid diffusion is important (Non-Patent Literature 2). However, since a chemically amplified resist composition improves sensitivity and contrast by diffusion of acid, if acid diffusion is suppressed to the limit by lowering the post-exposure bake (PEB) temperature or shortening the PEB time, etc., the sensitivity and contrast will be significantly reduced.

[0004] It is effective to add an acid generator that generates a bulky acid to suppress acid diffusion. Thus, it has been proposed to copolymerize an onium salt of a polymerizable olefin in a polymer to add an acid generator. However, in pattern formation of resist films of 16 nm or less in processing size, it is considered that from the viewpoint of acid diffusion, chemically amplified resist compositions have been unable to perform pattern formation, and the development of non-chemically amplified resist compositions is expected.

[0005] A material for a non-chemically amplified resist composition can be exemplified by polymethyl methacrylate (PMMA). PMMA is a positive resist material that improves the solubility in a developer of an organic solvent by cleavage of the main chain and reduction of the molecular weight due to EUV irradiation.

[0006] Hydrogensiloxane (HSQ) is crosslinked by condensation reaction of silanol generated by EUV irradiation, and thereby becomes a negative resist material that is insoluble in an alkali developer. Also, a chloro-substituted calixarene functions as a negative resist material. These negative resist materials, since the molecular size before crosslinking is small and there is no blurring due to acid diffusion, can be used as a pattern transfer material that is small in edge roughness and has very high resolution, and exhibits the resolution limit of an exposure device. However, these materials are insufficient in sensitivity, and further improvement is required.

[0007] A major cause of difficulty in developing materials for EUV lithography applications can be listed as the small number of photons in EUV exposure. The energy of EUV is much higher than that of ArF excimer laser, and the number of photons in EUV exposure is 1 / 14 of that in ArF exposure. In addition, the size of the pattern formed by EUV exposure is less than half of that by ArF exposure. Therefore, EUV exposure is easily affected by variations in the number of photons. The variation in the number of photons in the emission light region of the extremely short wavelength is shot noise, a physical phenomenon that cannot be eliminated. Therefore, so-called Stochastics is of concern. Although the effect of shot noise cannot be eliminated, how to reduce the effect is discussed. Due to the effect of shot noise, not only the size uniformity (CDU) and line width roughness (LWR) will increase, but there is also a probability of observing a hole blocking phenomenon of several millionths. If the hole is blocked, the transistor will not operate due to poor conduction, so it will have a bad effect on the performance of the entire device. When considering the sensitivity in practical use, the resist composition using PMMA and HSQ as the main component will be greatly affected by Stochastics, and the desired resolution performance cannot be obtained.

[0008] As a method for reducing the effect of shot noise from the resist aspect, the introduction of an element with a large absorption of EUV light is of concern. Patent Literature 1 proposes a chemical amplification resist composition containing iodine atoms with a large absorption of EUV light. However, as described above, a chemical amplification resist composition cannot achieve good resolution performance in EUV lithography in which the processing size is increasingly miniaturized in the future. In particular, in line and space patterns, as the pattern size becomes smaller, pattern collapse and line breakage also significantly increase, so reducing these cases is closely related to the improvement of the limit resolution.

[0009] Patent Literature 2 proposes a negative resist composition using a tin compound. It uses tin, which has a large absorption of EUV light, as the main component, so Stochastics is improved, and high sensitivity and high resolution can be achieved. However, such a metal resist has many problems such as insufficient solubility in a solvent for the resist, storage stability, defects caused by residues after etching, and the like. In addition, since the exposed portion of the metal resist becomes a metal oxide, it is a negative type that is not soluble in a developer, so when used for patterning of contact holes, an additional reversal processing step is required, and there are concerns about the cost.

[0010] Prior Art Documents

[0011] Patent Literature

[0012] [Patent Literature 1] Japanese Patent Application Publication No. 2018-5224

[0013] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2021-503482

[0014] Non-Patent Literature

[0015] [Non-Patent Literature 1] SPIE Vol. 5039 p1 (2003)

[0016] [Non-Patent Literature 2] SPIE Vol. 6520 p65203L-1 (2007) SUMMARY

[0017] [Problems to be Solved by the Invention]

[0018] The present invention has been made in view of the foregoing circumstances, and aims to provide a non-chemically amplified resist composition which is excellent in sensitivity and in limit resolution in optical lithography using high-energy rays, particularly in electron beam (EB) lithography and EUV lithography, and to provide a pattern forming method using the resist composition.

[0019] [Means for Solving the Problems]

[0020] As a result of repeated and intensive studies in order to achieve the foregoing object, the present inventors have obtained the following insight, and thus completed the present invention: a resist composition which uses a predetermined high-valent iodine compound, a carboxyl group-containing compound, and an onium salt compound as main components, can provide a resist film which is high in sensitivity and exhibits excellent resolution, and is extremely effective for precision fine processing.

[0021] That is, the present invention provides the following resist composition and pattern forming method.

[0022] 1. A resist composition comprising:

[0023] a high-valent iodine compound which is at least one of the following represented by any one of the following formulae (1) to (4),

[0024] an onium salt compound which contains a sulfonium cation represented by the following formula (5-1) or a sulfoxonium cation represented by the following formula (5-2), and a halide ion, a nitrate ion, a bisulfate ion, a hydrogen carbonate ion, a tetraphenylborate ion, or an anion represented by any one of the following formulae (5-3) to (5-9),

[0025] a carboxyl group-containing compound, and

[0026] a solvent.

[0027] [Chemical Formula 1]

[0028]

[0029] In the formula, m1 is 0, 1, or 2. When m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6. When m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8. When m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and 1 ≤ n1 + n2 ≤ 10. n3 is 1 or 2. n4 is 0, 1, 2, 3, or 4. However, 1 ≤ n3 + n4 ≤ 5. n5 is 1 or 2. n6 is 0, 1, 2, 3, or 4. However, 1 ≤ n5 + n6 ≤ 5. n7 is 0, 1, 2, 3, or 4. n8 is 1, 2, 3, or 4.

[0030] m2 is 0, 1, or 2. When m2 is 0, n9 is 0, 1, 2, 3, or 4. When m2 is 1, n9 is 0, 1, 2, 3, 4, 5, or 6. When m2 is 2, n9 is 0, 1, 2, 3, 4, 5, 6, 7, or 8.

[0031] R 1 ~R 8 Each group consists independently of a halogen atom or may contain heteroatoms and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 1 and R 2 R 3 and R 4 R 5 and R 6 、or R 7 and R 8 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0032] R 11 ~R 14 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. When n2 is 2 or more, each R 11 They can be the same or different, and there are multiple Rs. 11 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n4 is 2 or more, each R 12 They can be the same or different, and there are multiple Rs. 12 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n6 is 2 or more, each R 13 They can be the same or different, and there are multiple Rs. 13 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n7 is 2 or more, each R 14 They can be the same or different, and there are multiple Rs. 14 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0033] R15 is a (n8) valent hydrocarbon group having a carbon number of 1 to 40 or a (n8) valent heterocyclic group having a carbon number of 2 to 40, and when n8 is 2, R 15 may also be an ether bond, a carbonyl group, an azo group, a sulfide bond, a carbonate bond, a carbamate bond, a sulfinyl group, a sulfonyl group, or a thione bond. Also, part or all of the hydrogen atoms of the aforementioned (n8) valent hydrocarbon group or (n8) valent heterocyclic group can be substituted with a heteroatom-containing group, and part of the -CH2- of the aforementioned (n8) valent hydrocarbon group can also be substituted with a heteroatom-containing group, and R 14 and R 15 may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded and the atoms between the carbon atoms.

[0034] R 21 is a halogen atom or a hydrocarbon group having a carbon number of 1 to 10 which can also contain a heteroatom.

[0035] R 22 is a halogen atom or a hydrocarbon group having a carbon number of 1 to 40 which can also contain a heteroatom. When n9 is 2 or more, each R 22 may be the same or different. Also, a plurality of R 22 may also be bonded to each other and form a ring together with the carbon atoms of the aromatic ring to which they are bonded.

[0036] R 23 is a carbonyl group or a hydrocarbon group having a carbon number of 1 to 10 which can also contain a heteroatom.

[0037] *1 and *2 indicate atomic bonds to the carbon atoms of the aromatic ring in the formula. However, *1 and *2 are bonded to adjacent carbon atoms in the aromatic ring.

[0038] [Chemical Formula 2]

[0039]

[0040] in the formula, R 31 ~R 35 are each independently a halogen atom or a hydrocarbon group having a carbon number of 1 to 30 which can also contain a heteroatom. Also, R 31 and R 32 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded.

[0041] [Chemical Formula 3]

[0042]

[0043] in the formula, k1 and k2 are each independently 1, 2, 3, or 4.

[0044] Rf 1 and Rf 2 are each independently a hydrogen atom, a fluorine atom, or a fluorine-containing alkyl group having a carbon number of 1 to 6, but all of Rf1 and Rf 2 cannot be a hydrogen atom at the same time.

[0045] R 41 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom.

[0046] R 42 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom. However, the hydrogen atom on the carbon atom in the α- and β-positions to the sulfo group is replaced with a fluorine atom or a fluoroalkyl group.

[0047] R 51 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom.

[0048] R 52 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom. However, the hydrogen atom on the carbon atom in the α- and β-positions to the carboxyl group is replaced with a fluorine atom or a fluoroalkyl group.

[0049] R 61 and R 62 are each independently a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom.

[0050] R 71 to R 73 are each independently a hydrocarbon group having 1 to 50 carbon atoms which can also contain a hetero atom.

[0051] R 81 is a fluorine atom or a fluorinated hydrocarbon group having 1 to 10 carbon atoms, and the fluorinated hydrocarbon group can also contain a hydroxyl group, an ether bond or an ester bond. R 82 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group can also contain a hydroxyl group, an ether bond or an ester bond. Also, R 81 and R 82 may be bonded to each other and form a ring together with the atom to which they are bonded.

[0052] 2. The resist composition of 1, wherein the carboxyl group-containing compound is a polymer containing a repeating unit represented by the following formula (6) or a compound represented by the following formula (7).

[0053] [Chemical Formula 4]

[0054]

[0055] in the formula, R A is a hydrogen atom, a halogen atom, a methyl group or a trifluoromethyl group.

[0056] X A is a single bond, a phenylene group, a naphthylene group or a *-C(=O)-O-XA1 - X A1 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the saturated hydrocarbylene group can also have a hydroxyl group, an ether bond, an ester bond or a lactone ring. X represents a bond with a carbon atom of the main chain.

[0057] p is 1, 2, 3 or 4.

[0058] R 91 is a p-valent hydrocarbon group having 1 to 40 carbon atoms or a p-valent heterocyclic group having 2 to 40 carbon atoms, and when p is 2, R 91 may also be an ether bond, a carbonyl group, an azo group, a sulfide bond, a carbonate bond, a carbamate bond, a sulfinyl group or a sulfonyl group. Also, part or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be substituted with a heteroatom-containing group, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be substituted with a heteroatom-containing group.

[0059] R 92 is a single bond or a hydrocarbylene group having 1 to 10 carbon atoms, and part or all of the hydrogen atoms of the hydrocarbylene group can also be substituted with a heteroatom-containing group, and part of the -CH2- of the hydrocarbylene group can also be substituted with a heteroatom-containing group. When p is 2, 3 or 4, each R 92 may be the same or different.

[0060] 3. The resist composition of 2., wherein the polymer having a repeating unit represented by formula (6) does not contain an acid-labile group.

[0061] 4. A laminate, comprising:

[0062] a substrate, and

[0063] a resist film obtained from the resist composition according to any one of 1. to 3. on the substrate.

[0064] 5. The laminate of 4., comprising a resist underlayer film between the substrate and the resist film.

[0065] 6. The laminate of 4. or 5., wherein the resist film is formed by ligand exchange of the high-valent iodine compound with a carboxyl group-containing compound.

[0066] 7. A pattern forming method, comprising the steps of:

[0067] forming a resist film on a substrate or on an underlayer film of a substrate having the underlayer film using the resist composition according to any one of 1. to 3.,

[0068] exposing the resist film to i-ray, a KrF excimer laser, an ArF excimer laser, an electron beam or extreme ultraviolet light, and

[0069] The aforementioned exposed resist film is developed using a developer.

[0070] [Effects of the Invention]

[0071] The resist composition of the present application is extremely useful when high sensitivity and high resolution are taken into account and a fine pattern is formed in i-ray, KrF excimer laser, ArF excimer laser, EB lithography, and EUV lithography. DETAILED DESCRIPTION

[0072] [Resist Composition]

[0073] The resist composition of the present application contains a predetermined high-valent iodine compound, a carboxyl group-containing compound, and an onium salt compound as main components.

[0074] [High-Valent Iodine Compound]

[0075] The aforementioned high-valent iodine compound is at least one tridentate high-valent iodine compound represented by any one of the following formulas (1) to (4).

[0076] [Formula 5]

[0077]

[0078] In formulas (1) to (4), m1 is 0, 1, or 2. When m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6. When m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8. When m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9, and 1 ≤ n1 + n2 ≤ 10. n3 is 1 or 2. n4 is 0, 1, 2, 3, or 4. However, 1 ≤ n3 + n4 ≤ 5. n5 is 1 or 2. n6 is 0, 1, 2, 3, or 4. However, 1 ≤ n5 + n6 ≤ 5. n7 is 0, 1, 2, 3, or 4. n8 is 1, 2, 3, or 4. m2 is 0, 1, or 2. When m2 is 0, n9 is 0, 1, 2, 3, or 4. When m2 is 1, n9 is 0, 1, 2, 3, 4, 5, or 6. When m2 is 2, n9 is 0, 1, 2, 3, 4, 5, 6, 7, or 8.

[0079] In formulas (1) to (3), R 1 to R 8 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which can also contain a hetero atom. Also, R 1 and R 2 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which can also contain a hetero atom. Also, R 3 and R 4 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which can also contain a hetero atom. Also, R 5 and R 6 are each independently a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms which can also contain a hetero atom. Also, R 7and R 8 Also, R

[0080] R 1 ~R 8 The halogen atom represented by R 1 ~R 8 The hydrocarbon group having a carbon number of 1 to 10 represented by R 2,6 may be either saturated or unsaturated, and can be any one of linear, branched, or cyclic. Specific examples thereof can include alkyl groups having a carbon number of 1 to 10 such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, t-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, and the like; cyclic saturated hydrocarbon groups having a carbon number of 3 to 10 such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.02'6]decyl, adamantyl, and the like; alkenyl groups such as vinyl, allyl, and the like; aryl groups having a carbon number of 6 to 10 such as phenyl, naphthyl, and the like; and groups obtained by combining these. Also, a part or all of the hydrogen atoms of the aforementioned hydrocarbon groups can be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, and the like, and a part of the -CH2- groups of the aforementioned hydrocarbon groups can be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and the like. As a result, they can contain hydroxyl groups, cyano groups, halogen atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate ester bonds, carbonate ester bonds, carbamate ester bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-O-C(=O)-), and the like. 1 ~R 8 Preferably, it is a hydrocarbon group having a carbon number of 1 to 4.

[0081] In formulae (1) to (3), R 11 ~R 14 is a halogen atom or a hydrocarbon group having a carbon number of 1 to 40 that can also contain heteroatoms. When n2 is 2 or more, each R 11 may be the same or different, and a plurality of R 11 may be bonded to each other and form a ring together with the carbon atoms of the aromatic ring to which they are bonded. When n4 is 2 or more, each R 12 may be the same or different, and a plurality of R 12 may be bonded to each other and form a ring together with the carbon atoms of the aromatic ring to which they are bonded. When n6 is 2 or more, each R 13 may be the same or different, and a plurality of R 13 may be bonded to each other and form a ring together with the carbon atoms of the aromatic ring to which they are bonded. When n7 is 2 or more, each R 14 may be the same or different, and a plurality of R 14They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0082] R 11 ~R 14 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 11 ~R 14 The hydrocarbon groups representing 1 to 40 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 [Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, and anthracene. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, these groups may contain hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc.]

[0083] In equation (3), R 15 R is a (n8) valence hydrocarbon group with 1 to 40 carbon atoms or a (n8) valence heterocyclic group with 2 to 40 carbon atoms. When (n8) is 2, R 15 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, sulfonyl group, or thionyl bond. Furthermore, some or all of the hydrogen atoms in the aforementioned (n8) valence hydrocarbon group or (n8) valence heterocyclic group can be substituted by a group containing a heteroatom, and part of the -CH2- of the aforementioned (n8) valence hydrocarbon group can also be substituted by a group containing a heteroatom, and R... 14 and R 15 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0084] R 15The (n8) valent hydrocarbon group represented by the formula (n8) can be either saturated or unsaturated, and can be any one of linear, branched, or cyclic. The aforementioned (n8) valent hydrocarbon group is a group obtained by removing (n8) hydrogen atoms from a hydrocarbon. The aforementioned hydrocarbon can include, for example, an alkane having 1 to 40 carbon atoms, an alkene having 2 to 40 carbon atoms, an alkyne having 2 to 40 carbon atoms, a cyclic saturated hydrocarbon having 3 to 40 carbon atoms, a cyclic unsaturated hydrocarbon having 3 to 40 carbon atoms, and an aromatic hydrocarbon having 6 to 40 carbon atoms.

[0085] Specific examples of the aforementioned alkane having 1 to 40 carbon atoms can include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, structural isomers thereof, and the like.

[0086] Specific examples of the aforementioned alkene having 2 to 40 carbon atoms can include ethylene, propylene, butylene, pentene, hexene, heptene, octene, nonene, decene, structural isomers thereof, and the like.

[0087] Specific examples of the aforementioned alkyne having 2 to 40 carbon atoms can include acetylene, propyne, butyne, pentyne, hexyne, heptyne, octyne, nonyne, decyne, structural isomers thereof, and the like.

[0088] Specific examples of the aforementioned cyclic saturated hydrocarbon having 3 to 40 carbon atoms can include cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norbornane, and the like.

[0089] Specific examples of the aforementioned cyclic unsaturated hydrocarbon having 3 to 40 carbon atoms can include cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornene, and the like.

[0090] Specific examples of the aforementioned aromatic hydrocarbon having 6 to 40 carbon atoms can include benzene, naphthalene, biphenyl, and the like.

[0091] R 15 The (n8) valent heterocyclic group represented by the formula (n8) is a group obtained by removing (n8) hydrogen atoms from a heterocyclic compound. The aforementioned heterocyclic compound can include, for example, furan, pyridine, pyrazole, tetrahydrothiazole, and the like.

[0092] R 15 A part or all of the hydrogen atoms of the (n8) valent hydrocarbon group or the (n8) valent heterocyclic group represented by the formula (n8) can also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, and the like, and as a result, can also contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Also, in the aforementioned (n8) valent hydrocarbon group, a part of -CH2- constituting it can also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, and the like, and as a result, can also contain a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate ester bond, a carbamate ester bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), and the like.

[0093] In the formula (4), R 21A hydrocarbon group having 1 to 10 carbon atoms which is a halogen atom or can also contain a hetero atom. R 21 Specific examples of the halogen atom and the hydrocarbon group represented by R 1 ~R 8 Specific examples of the halogen atom and the hydrocarbon group represented by R

[0094] In formula (4), R 22 is a halogen atom or a hydrocarbon group having 1 to 40 carbon atoms which can also contain a hetero atom. When n9 is 2 or more, each R 22 may be the same or different. Also, a plurality of R 22 may be bonded to each other and form a ring together with the carbon atom of the aromatic ring to which they are bonded. R 22 Specific examples of the halogen atom and the hydrocarbon group represented by R 11 ~R 14 Specific examples of the halogen atom and the hydrocarbon group represented by R

[0095] In formula (4), R 23 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms which can also contain a hetero atom. The hydrocarbylene group having 1 to 10 carbon atoms described above can be either saturated or unsaturated, and can be any of a straight chain, a branched chain, or a ring. Specific examples thereof include methanediyl, ethane-l, l-diyl, ethane-l,2-diyl, propane-l, l-diyl, propane-l,2-diyl, propane-l,3-diyl, propane-2,2-diyl, butane-2,3-diyl, butane-l,4-diyl, 2-methylpropane-l,2-diyl, pentane-l,5-diyl, hexane-l,6-diyl, heptane-l,7-diyl, octane-l,8-diyl, nonane-l,9-diyl, decane-l, lO-diyl, and the like, which are alkylene groups having 1 to 10 carbon atoms; cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl, tricyclo[5.2.1.0 2,6 ]decane-diyl, and the like, which are cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms; ethenylene, propenylene, and the like, which are alkenylene groups having 2 to 10 carbon atoms; phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, naphthylene, and the like, which are arylene groups having 6 to 10 carbon atoms; and groups obtained by combining these. Also, a part or all of the hydrogen atoms of the aforementioned hydrocarbylene group can be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, and the like, and a part of -CH2- of the aforementioned hydrocarbylene group can also be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, and the like, as a result of which it can also contain a hydroxyl group, a cyano group, a halogenated alkyl group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate ester bond, a carbamate ester bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-O-C(=O)-), and the like. R 23 is preferably a carbonyl group, a hydrocarbylene group having 1 to 4 carbon atoms, or a fluorinated hydrocarbylene group having 1 to 4 carbon atoms.

[0096] In formula (4), *1 and *2 represent atomic bonds to carbon atoms of the aromatic ring in formula (4). However, *1 and *2 are bonded to adjacent carbon atoms in the aromatic ring. Combinations of *1, *2, and m2 can be considered in the following 7 patterns.

[0097] [Chemical 6]

[0098]

[0099] In the formula, n9, R 22 and R 23 are the same as described above. The dotted line indicates an atomic bond to -C(=O)-O-. 21

[0100] Specific examples of the hypervalent iodine compound represented by formula (1) can include, but are not limited to, the following.

[0101] [Chemical 7]

[0102]

[0103] [Chemical 8]

[0104]

[0105] [Chemical 9]

[0106]

[0107] [Chemical 10]

[0108]

[0109] [Chemical 11]

[0110]

[0111] [Chemical 12]

[0112]

[0113] [Chemical 13]

[0114]

[0115] [Chemical 14]

[0116]

[0117] [Chemical 15]

[0118]

[0119] [Chemical 16] ​

[0120]

[0121] [Chem. 17]

[0122]

[0123] [Chem. 18]

[0124]

[0125] Specific examples of the hypervalent iodine compound represented by formula (2) can include, but are not limited to, the following.

[0126] [Chem. 19]

[0127]

[0128] [Chem. 20]

[0129]

[0130] [Chem. 21]

[0131]

[0132] [Chem. 22]

[0133]

[0134] Specific examples of the hypervalent iodine compound represented by formula (3) can include, but are not limited to, the following.

[0135] [Chem. 23]

[0136]

[0137] [Chem. 24]

[0138]

[0139] [Chem. 25]

[0140]

[0141] [Chem. 26]

[0142]

[0143] [Chem. 27]

[0144]

[0145] [Chem. 28]

[0146]

[0147] Specific examples of the high-valent iodine compound represented by formula (4) can include, but are not limited to, the following. In the following formulae, Me represents a methyl group.

[0148] [Chemical Formula 29]

[0149]

[0150] [Chemical Formula 30]

[0151]

[0152] [Chemical Formula 31]

[0153]

[0154] [Chemical Formula 32]

[0155]

[0156] [Chemical Formula 33]

[0157]

[0158] [Chemical Formula 34]

[0159]

[0160] [Chemical Formula 35]

[0161]

[0162] [Chemical Formula 36]

[0163]

[0164] [Chemical Formula 37]

[0165]

[0166] [Chemical Formula 38]

[0167]

[0168] [Chemical Formula 39]

[0169]

[0170] [Chemical Formula 40]

[0171]

[0172] [Chemical Formula 41]

[0173]

[0174] [Chemical Formula 42]

[0175]

[0176] [Chem. 43]

[0177]

[0178] [Chem. 44]

[0179]

[0180] [Chem. 45]

[0181]

[0182] [Chem. 46]

[0183]

[0184] [Chem. 47]

[0185]

[0186] [Chem. 48]

[0187]

[0188] [Chem. 49]

[0189]

[0190] [Chem. 50]

[0191]

[0192] [Chem. 51]

[0193]

[0194] [Chem. 52]

[0195]

[0196] [Chem. 53]

[0197]

[0198] [Chem. 54]

[0199]

[0200] [Chem. 55]

[0201]

[0202] [Chem. 56]

[0203]

[0204] [Chem. 57]

[0205]

[0206] [Chem. 58]

[0207]

[0208] [Chem. 59]

[0209]

[0210] [Chem. 60]

[0211]

[0212] [Chem. 61]

[0213]

[0214] [Chem. 62]

[0215]

[0216] [Chem. 63]

[0217]

[0218] [Chem. 64]

[0219]

[0220] [Chem. 65]

[0221]

[0222] [Chem. 66]

[0223]

[0224] [Chem. 67]

[0225]

[0226] [Chem. 68]

[0227]

[0228] [Chem. 69]

[0229]

[0230] [Chem. 70]

[0231]

[0232] [Chem. 71]

[0233]

[0234] [Chem. 72]

[0235]

[0236] [Chem. 73]

[0237]

[0238] [Chem. 74]

[0239]

[0240] [Chem. 75]

[0241]

[0242] [Chem. 76]

[0243]

[0244] [Chem. 77]

[0245]

[0246] [Chem. 78]

[0247]

[0248] [Chem. 79]

[0249]

[0250] [Chem. 80]

[0251]

[0252] [Chem. 81]

[0253]

[0254] [Chem. 82]

[0255]

[0256] [Chem. 83]

[0257]

[0258] [Chem. 84]

[0259]

[0260] [Onium salt compound]

[0261] The aforementioned onium salt compound contains a sulfonium cation represented by the following formula (5-1) or a sulfoxonium cation represented by the following formula (5-2) as a cation.

[0262] [Chemical Formula 85]

[0263]

[0264] In the formulae (5-1) and (5-2), R 31 ~R 35 are each independently a halogen atom or a hydrocarbon group having a carbon number of 1 to 30 which can also contain a hetero atom.

[0265] R 31 ~R 35 The specific examples of the halogen atom represented by R

[0266] R 31 ~R 35 The hydrocarbon group represented by R

[0267] R 31 and R 32 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the specific examples of the aforementioned ring structure can include those represented by the following formulae.

[0268] [Chemical Formula 86]

[0269]

[0270] in the formula, dotted line is a bond to R 33

[0271] Specific examples of the sulfonium cation represented by formula (5-1) can include, but are not limited to, the following.

[0272] [Chem. 87]

[0273]

[0274] [Chem. 88]

[0275]

[0276] [Chem. 89]

[0277]

[0278] [Chem. 90]

[0279]

[0280] [Chem. 91]

[0281]

[0282] [Chem. 92]

[0283]

[0284] [Chem. 93]

[0285]

[0286] [Chem. 94]

[0287]

[0288] [Chem. 95]

[0289]

[0290] [Chem. 96]

[0291]

[0292] [Chem. 97]

[0293]

[0294] [Chem. 98]

[0295]

[0296] [Chem. 99]​

[0297]

[0298] [Chemical Formula 100]

[0299]

[0300] [Chemical Formula 101]

[0301]

[0302] [Chemical Formula 102]

[0303]

[0304] [Chemical Formula 103]

[0305]

[0306] [Chemical Formula 104]

[0307]

[0308] [Chemical Formula 105]

[0309]

[0310] [Chemical Formula 106]

[0311]

[0312] [Chemical Formula 107]

[0313]

[0314] [Chemical Formula 108]

[0315]

[0316] [Chemical Formula 109]

[0317]

[0318] [Chemical Formula 110]

[0319]

[0320] [Chemical Formula 111]

[0321]

[0322] [Chemical Formula 112]

[0323]

[0324] [Chemical Formula 113]

[0325]

[0326] Specific examples of the onium cation represented by formula (5-2) can include, but are not limited to, those shown below.

[0327] [Chemical Formula 114]

[0328]

[0329] [Chemical Formula 115]

[0330]

[0331] The aforementioned onium salt compound contains a halide ion, a nitrate ion, a hydrogen sulfate ion, a hydrogen carbonate ion, a tetraphenylborate ion, or any one of those represented by the following formulae (5-3) to (5-9) as an anion.

[0332] [Chemical Formula 116]

[0333]

[0334] In formulae (5-3) and (5-5), k1 and k2 are each independently 1, 2, 3, or 4. Rf 1 and Rf 2 are each independently a hydrogen atom, a fluorine atom, or a fluorine-containing alkyl group having a carbon number of 1 to 6, but all of Rf 1 and Rf 2 cannot be hydrogen atoms at the same time.

[0335] In formula (5-3), R 41 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having a carbon number of 1 to 50, which can also contain a heteroatom.

[0336] In formula (5-4), R 42 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having a carbon number of 1 to 50, which can also contain a heteroatom. However, the hydrogen atoms on the carbon atoms at the α- and β-positions of the sulfo group are excluded, and are replaced with fluorine atoms or fluorine alkyl groups.

[0337] In formula (5-5), R 51 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having a carbon number of 1 to 50, which can also contain a heteroatom.

[0338] In formula (5-6), R 52 is a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group having a carbon number of 1 to 50, which can also contain a heteroatom. However, the hydrogen atoms on the carbon atoms at the α- and β-positions of the carboxyl group are excluded, and are replaced with fluorine atoms or fluorine alkyl groups.

[0339] In formula (5-7), R 61 and R62 Each can be an independent hydrocarbon group with 1 to 50 carbon atoms, which may also contain heteroatoms.

[0340] In equation (5-8), R 71 ~R 73 Each can be an independent hydrocarbon group with 1 to 50 carbon atoms, which may also contain heteroatoms.

[0341] In equation (5-9), R 81 It is a fluorine atom or a fluorinated hydrocarbon group having 1 to 10 carbon atoms, and the fluorinated hydrocarbon group may also contain a hydroxyl group, an ether bond, or an ester bond. R 82 It consists of a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and this hydrocarbon group may also contain a hydroxyl group, an ether bond, or an ester bond. Also, R 81 and R 82 They can also bond to each other and form rings together with the atoms they are bonded to.

[0342] The anion of the aforementioned onium salt compound is preferably a halide ion, nitrate ion, or any anion represented by formulas (5-3) to (5-9), and it is more preferable that it is a halide ion, nitrate ion, or anion represented by formulas (5-4), (5-6), or (5-8).

[0343] R 41 R 42 R 51 R 52 R 61 R 62 R 71 R 72 and R 73 The hydrocarbon groups representing 1 to 50 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 50 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, tricyclic [5.2.1.0] 2,6cyclohexenyl group, and the like. Further, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group can be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, and the like, and a part of -CH2- constituting the aforementioned hydrocarbon group can also be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, and the like, and as a result, it can also contain a hydroxyl group, a cyano group, a halogen atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate ester bond, a carbamate ester bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=0)-0-C(=0)-), and the like.

[0344] R 81 A fluorinated hydrocarbon group represented by Rf1-Rf2-Rf3-Rf4-Rf5-Rf6-Rf7-Rf8-Rf9-Rf10indicates a group in which a part or all of the hydrogen atoms of a hydrocarbon group having a carbon number of 1 to 10 are substituted with a fluorine atom. The aforementioned hydrocarbon group having a carbon number of 1 to 10 can be either saturated or unsaturated, and can be any one of linear, branched, and cyclic. Specific examples thereof can be exemplified by a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a neopentyl group, a neohexyl group, a neooctyl group, a neodecyl group, a neododecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a cyclododecyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, and the like. 41 , R 42 , R 51 , R 52 , R 61 , R 62 , R 71 , R 72 , and R 73 indicate examples in which the carbon number in a hydrocarbon group having a carbon number of 1 to 50 is 1 to 10.

[0345] R 82 A hydrocarbon group represented by R1-R2-R3-R4-R5-R6-R7-R8-R9-R10indicates a group in which a part or all of the hydrogen atoms of a hydrocarbon group having a carbon number of 1 to 20 are substituted with a fluorine atom. The aforementioned hydrocarbon group having a carbon number of 1 to 20 can be either saturated or unsaturated, and can be any one of linear, branched, and cyclic. Specific examples thereof can be exemplified by a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a neopentyl group, a neohexyl group, a neooctyl group, a neodecyl group, a neododecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a cyclododecyl group, a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, and the like. 41 , R 42 , R 51 , R 52 , R 61 , R 62 , R 71 , R 72 , and R 73 indicate examples in which the carbon number in a hydrocarbon group having a carbon number of 1 to 50 is 1 to 20.

[0346] Any one of the anions represented by Formulas (5-3) to (5-9) can also have a hydrocarbon group having a carbon number of 2 to 50 containing a polymerizable functional group in its structure and can also contain a hetero atom. Specific examples thereof can be exemplified by the following, but are not limited thereto.

[0347] [Chemical Formula 117]

[0348]

[0349] [Chemical Formula 118]

[0350]

[0351] [Chemical Formula 119]

[0352]

[0353] [Chemical Formula 120]

[0354]

[0355] Specific examples of the anion represented by formula (5-3) can include, but are not limited to, the following. In the following formulae, Ac is an acetyl group, Rf is a C1-4 fluorinated alkyl group, and R is a C1-4 alkyl group. 1 and the same as described above.

[0356] [Chemical Formula 121]

[0357]

[0358] [Chemical Formula 122]

[0359]

[0360] [Chemical Formula 123]

[0361]

[0362] [Chemical Formula 124]

[0363]

[0364] [Chemical Formula 125]

[0365]

[0366] [Chemical Formula 126]

[0367]

[0368] [Chemical Formula 127]

[0369]

[0370] [Chemical Formula 128]

[0371]

[0372] [Chemical Formula 129]

[0373]

[0374] [Chemical Formula 130]

[0375]

[0376] [Chemical Formula 131]

[0377]

[0378] [Chemical Formula 132]

[0379]

[0380] [Chemical Formula 133]

[0381]

[0382] Specific examples of the anion represented by formula (5-4) can include, but are not limited to, the following.

[0383] [Chemical Formula 134]

[0384]

[0385] [Chemical Formula 135]

[0386]

[0387] [Chemical Formula 136]

[0388]

[0389] [Chemical Formula 137]

[0390]

[0391] [Chemical Formula 138]

[0392]

[0393] [Chemical Formula 139]

[0394]

[0395] Specific examples of the anion represented by formula (5-5) can include, but are not limited to, the following.

[0396] [Chemical Formula 140]

[0397]

[0398] [Chemical Formula 141]

[0399]

[0400] Specific examples of the anion represented by formula (5-6) can include, but are not limited to, the following.

[0401] [Chemistry 142]

[0402]

[0403] [Chemistry 143]

[0404]

[0405] [Chemistry 144]

[0406]

[0407] [Chemistry 145]

[0408]

[0409] Specific examples of anions represented by equations (5-7) are listed below, but are not limited to these.

[0410] [Chemistry 146]

[0411]

[0412] [Chemistry 147]

[0413]

[0414] Specific examples of anions represented by equations (5-8) are listed below, but are not limited to these.

[0415] [Chemistry 148]

[0416]

[0417] [Chemistry 149]

[0418]

[0419] [Chemistry 150]

[0420]

[0421] Specific examples of anions represented by equations (5-9) are listed below, but are not limited to these.

[0422] [Chemistry 151]

[0423]

[0424] [Chemistry 152]

[0425]

[0426] Specific examples of onium salts represented by equation (5) can be listed by any combination of the aforementioned anions and cations.

[0427] The onium salt represented by formula (5) can be used alone or in combination with two or more. When two or more onium salts represented by formula (5) are used in combination, it is preferable to use a photoacid generator that generates an acid of different acidity, and by using a photoacid generator that generates an acid of low acidity to quench the acid generated in the exposed portion of the resist to diffuse to the unexposed portion, diffusion can be suppressed and a high-resolution pattern can be formed.

[0428] The onium salt represented by formula (5) can be desirably used as a photoacid generator.

[0429] In the resist composition of the present application, the ratio of the content of the high-valent iodine compound and the photoacid generator is preferably, in terms of molar ratio, high-valent iodine compound: photoacid generator = 1 : 1000 to 1000 : 1, and more preferably 1 : 500 to 500 : 1.

[0430] When the aforementioned onium salt is introduced into a substituent having a large molecular weight and a large volume, diffusion of the generated acid can be suppressed to a high degree due to the large volume, and thus is desirable for fine pattern formation.

[0431] When the aforementioned onium salt has an element such as a fluorine atom or an iodine atom that has a high absorption effect for EUV light, the amount of secondary electrons generated increases, and decomposition of the cation is promoted, and thus is desirable for high-sensitivity fine pattern formation.

[0432] [Carboxyl group-containing compound]

[0433] The aforementioned carboxyl group-containing compound is preferably a polymer having a repeating unit represented by the following formula (6) or a compound represented by the following formula (7).

[0434] [Chemical 153]

[0435]

[0436] In formula (6), R A is a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. X A is a single bond, a phenylene group, a naphthylene group, or *-C(=O)-O-X A1 -. X A1 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the saturated hydrocarbylene group can also have a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents an atomic bond to the carbon atom of the main chain.

[0437] In formula (7), p is 1, 2, 3, or 4.

[0438] In formula (7), R 91 is a p-valent hydrocarbon group having 1 to 40 carbon atoms or a p-valent heterocyclic group having 2 to 40 carbon atoms, and when p is 2, R 91It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, or sulfonyl group. Furthermore, some or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be replaced by a group containing a heteroatom.

[0439] R 91 The p-valent hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. The aforementioned p-valent hydrocarbon group is a group obtained by removing p hydrogen atoms from a hydrocarbon. Examples of such hydrocarbons include: alkanes with 1-40 carbon atoms, alkenes with 2-40 carbon atoms, alkynes with 2-40 carbon atoms, cyclic saturated hydrocarbons with 3-40 carbon atoms, cyclic unsaturated hydrocarbons with 3-40 carbon atoms, and aromatic hydrocarbons with 6-40 carbon atoms.

[0440] Specific examples of alkanes with 1 to 40 carbon atoms include: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and their structural isomers.

[0441] Specific examples of the aforementioned alkenes with 2 to 40 carbon atoms include: ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and their structural isomers.

[0442] Specific examples of the aforementioned alkynes with 2 to 40 carbon atoms include: acetylene, propyne, butyne, pentyne, hexyne, heptyne, octyne, nonyne, decyne, and their structural isomers.

[0443] Specific examples of the aforementioned cyclic saturated hydrocarbons with 3 to 40 carbon atoms include: cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norcamphene, etc.

[0444] Specific examples of the aforementioned cyclic unsaturated hydrocarbons with 3 to 40 carbon atoms include: cyclopropylene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and norcamphene.

[0445] Specific examples of aromatic hydrocarbons with 6 to 40 carbon atoms mentioned above include: benzene, naphthalene, biphenyl, etc.

[0446] R 91 The p-valent heterocyclic group refers to a group derived from a heterocyclic compound by removing p hydrogen atoms. Specific examples of the aforementioned heterocyclic compounds include furan, pyridine, pyrazole, and tetrahydrothiazole.

[0447] A part or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can also be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and as a result, a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. can also be contained. Also, in the aforementioned p-valent hydrocarbon group, a part of the -CH2- groups constituting it can also be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=0)-0-C(=0)-), etc. can also be contained.

[0448] In formula (7), R 92 is a single bond or a hydrocarbylene group having a carbon number of 1 to 10, and a part or all of the hydrogen atoms of the hydrocarbylene group can also be substituted with a hetero atom-containing group, and a part of the -CH2- groups of the hydrocarbylene group can also be substituted with a hetero atom-containing group. When p is 2, 3, or 4, each R 92 may be the same or different.

[0449] R 92 The hydrocarbylene group represented by R may be saturated or unsaturated, and can be any one of linear, branched, or cyclic. Specific examples thereof can include methanediyl, ethane-1, 1-diyl, ethane-1, 2-diyl, propane-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, etc. alkanediyl groups having a carbon number of 1 to 10; cyclopentanediyl, cyclohexanediyl, norbornanediyl, adamantanediyl, etc. cyclic saturated hydrocarbylene groups having a carbon number of 3 to 10; ethenylene, propen-1, 3-diyl, etc. unsaturated aliphatic hydrocarbylene groups having a carbon number of 2 to 10; phenylene, naphthylene, etc. arylene groups having a carbon number of 6 to 10; groups obtained by combining them; etc. Also, a part or all of the hydrogen atoms of the aforementioned hydrocarbylene group can also be substituted with a hetero atom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of the -CH2- groups constituting the aforementioned hydrocarbylene group can also be substituted with a hetero atom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a carbamate bond, a lactone ring, a sultone ring, a carboxylic anhydride, etc. can also be contained.

[0450] Among the carboxylic acid compounds represented by formula (7), it is preferable that p be an integer of 2 to 4. At this time, when mixed with a hypervalent iodine compound, a high-molecular-weight, firm resist film is easily formed, and from the viewpoint of etching resistance, developer resistance, etc., it is preferable.

[0451] Specific examples of the carboxyl group-containing repeating unit represented by formula (6) can be exemplified by the following, but are not limited thereto. Note that, in the following formulae, R A and the foregoing.

[0452] [Chemical Formula 154]

[0453]

[0454] [Chemical Formula 155]

[0455]

[0456] Specific examples of the aforementioned carboxylic acid compound represented by formula (7) can be exemplified by the following, but are not limited thereto.

[0457] [Chemical Formula 156]

[0458]

[0459] [Chemical Formula 157]

[0460]

[0461] [Chemical Formula 158]

[0462]

[0463] [Chemical Formula 159]

[0464]

[0465] [Chemical Formula 160]

[0466]

[0467] [Chemical Formula 161]

[0468]

[0469] The aforementioned carboxyl group-containing polymer containing the repeating unit represented by formula (6) can further contain a repeating unit other than the aforementioned carboxyl group-containing repeating unit (hereinafter also referred to as other repeating unit). The aforementioned other repeating unit is not particularly limited, and is preferably a repeating unit that improves the solubility of a polymer having only a carboxyl group- containing repeating unit that is difficult to dissolve in a solvent.

[0470] Further, the aforementioned other repeating unit is preferably a repeating unit having a cyclic structure that is expected to have high etching resistance due to a rigid skeleton, or a repeating unit having a styrene skeleton as a main component.

[0471] Specific examples of the aforementioned other repeating unit can be exemplified by the following, but are not limited thereto. Note that, in the following formulae, R A and the foregoing, X Bare each independently -CH2- or -0-.

[0472] [Chemical Formula 162]

[0473]

[0474] [Chemical Formula 163]

[0475]

[0476] [Chemical Formula 164]

[0477]

[0478] [Chemical Formula 165]

[0479]

[0480] [Chemical Formula 166]

[0481]

[0482] [Chemical Formula 167]

[0483]

[0484] [Chemical Formula 168]

[0485]

[0486] [Chemical Formula 169]

[0487]

[0488] [Chemical Formula 170]

[0489]

[0490] [Chemical Formula 171]

[0491]

[0492] [Chemical Formula 172]

[0493]

[0494]

[0495]

[0496] [Chemical Formula 174]

[0497]

[0498] [Chemical Formula 175]

[0499]

[0500] [Chemical Formula 176]

[0501]

[0502] [Chemical Formula 177]

[0503]

[0504] [Chemical Formula 178]

[0505]

[0506] [Chemical Formula 179]

[0507]

[0508] [Chemical Formula 180]

[0509]

[0510] [Chemical Formula 181]

[0511]

[0512] [Chemical Formula 182]

[0513]

[0514] [Chemical Formula 183]

[0515]

[0516] [Chemical Formula 184]

[0517]

[0518] [Chemical Formula 185]

[0519]

[0520] [Chemical Formula 186]

[0521]

[0522] [Chemical Formula 187]

[0523]

[0524] [Chemical Formula 188]

[0525]

[0526] [Chemical Formula 189]

[0527]

[0528] [Chemical Formula 19]

[0529]

[0530] [Chemical Formula 20]

[0531]

[0532] In the aforementioned carboxyl group-containing polymer, the content ratio (molar ratio) of the high-valent iodine compound to the carboxyl group-containing compound (when the carboxyl group-containing compound is a carboxyl group-containing polymer, the content ratio of the high-valent iodine compound to the carboxyl group-containing repeating unit in the aforementioned polymer) is preferably high-valent iodine compound : carboxyl group-containing compound = 10 : 90 to 90 : 10, more preferably 20 : 80 to 80 : 20, and even more preferably 30 : 70 to 70 : 30. The aforementioned high-valent iodine compound can be used alone or in combination with two or more kinds. The aforementioned carboxyl group-containing polymer can be used alone or in combination with two or more kinds having different composition ratios, Mw, and / or Mw / Mn.

[0533] The weight average molecular weight (Mw) of the aforementioned carboxyl group-containing polymer is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. In addition, in the present application, Mw is a value measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and is a value converted to polystyrene.

[0534] Further, in the aforementioned carboxyl group-containing polymer, when the molecular weight distribution (Mw / Mn) is wide, there are concerns that low-molecular-weight and high-molecular-weight polymers are present, and that foreign matter is observed on a pattern after exposure, or the pattern shape deteriorates. Therefore, as the pattern becomes regular and finer, the influence of Mw and Mw / Mn tends to become greater, and thus in order to obtain a resist composition that can be desirably used for a fine pattern size, the Mw / Mn of the aforementioned carboxyl group-containing polymer is preferably narrow, and is preferably 1.0 to 2.0.

[0535] In the resist composition of the present application, the content ratio (molar ratio) of the aforementioned high-valent iodine compound to the aforementioned carboxyl group-containing compound (when the carboxyl group-containing compound is a carboxyl group-containing polymer, the content ratio of the high-valent iodine compound to the carboxyl group-containing repeating unit in the aforementioned polymer) is preferably high-valent iodine compound : carboxyl group-containing compound = 10 : 90 to 90 : 10, more preferably 20 : 80 to 80 : 20, and even more preferably 30 : 70 to 70 : 30. The aforementioned high-valent iodine compound can be used alone or in combination with two or more kinds. The aforementioned carboxyl group-containing polymer can be used alone or in combination with two or more kinds having different composition ratios, Mw, and / or Mw / Mn.

[0536] The aforementioned carboxyl group-containing polymer can be synthesized, for example, by a method in which a monomer that provides the aforementioned repeating unit is added to an organic solvent, a radical polymerization initiator is added, and heating is performed to cause polymerization.

[0537] Specific examples of the organic solvent used in the polymerization reaction include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, cyclopentanone, cyclohexanone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), and the like. Specific examples of the aforementioned polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropanoate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauryl peroxide, and the like. The amount of the aforementioned polymerization initiator to be added is preferably 0.01 to 25 mol% relative to the total amount of the monomers to be polymerized. The reaction temperature is preferably 50 to 150°C, and more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and more preferably 2 to 12 hours from the viewpoint of production efficiency.

[0538] The aforementioned polymerization initiator can be added to the aforementioned monomer solution and supplied to the reaction vessel, or a separate initiator solution different from the aforementioned monomer solution can be prepared and supplied to the reaction vessel independently. Since there is a possibility that the polymerization reaction proceeds and an ultrahigh molecular weight substance is generated due to the radicals generated from the initiator during the standby time, the monomer solution and the initiator solution are preferably prepared and dropped independently from the viewpoint of quality management. Also, in order to adjust the molecular weight, a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol can be used in combination. In this case, the amount of the aforementioned chain transfer agent to be added is preferably 0.01 to 20 mol% relative to the total amount of the monomers to be polymerized.

[0539] In addition, the amount of each monomer in the aforementioned monomer solution is appropriately set so as to become the desired content ratio of the aforementioned repeating unit, for example.

[0540] [Solvent]

[0541] The resist composition of the present application contains a solvent. The aforementioned solvent is not particularly limited as long as it can dissolve the aforementioned high-valent iodine compound, the carboxyl group-containing compound, and the other components described later, and can form a film. Such a solvent is preferably an organic solvent, and specific examples thereof include ketones such as cyclohexanone, methyl-2-n-pentyl ketone, and methyl isopentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, and 4-methyl-2-pentanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono-t-butyl ether acetate, and methyl 2-hydroxyisobutyrate; carboxylic acids such as formic acid, acetic acid, and propionic acid; lactones such as γ-butyrolactone; and a mixture solvent thereof.

[0542] In the resist composition of the present application, the content of the aforementioned solvent is preferably an amount in which the concentration of solid components in the resist composition becomes 0.1 to 20% by mass, more preferably an amount in which the concentration of solid components in the resist composition becomes 0.1 to 15% by mass, and still more preferably an amount in which the concentration of solid components in the resist composition becomes 0.1 to 10% by mass. In addition, the solid components in the present application refer to the total of components other than the solvent among all components of the resist composition. The aforementioned solvent can be used alone as one kind, or can be used in combination as two or more kinds.

[0543] [Other components]

[0544] The resist composition of the present application can further contain a surfactant. The aforementioned surfactant is preferably a fluorine-based and / or silicone-based surfactant. Such a surfactant can include the surfactants described in paragraph

[0276] of U.S. Patent Application Publication No. 2008 / 0248425. In addition, a surfactant other than the fluorine-based and / or silicone-based surfactants described in paragraph

[0280] of U.S. Patent Application Publication No. 2008 / 0248425 can also be used.

[0545] When the resist composition of the present application contains the aforementioned surfactant, the content thereof is preferably 0.0001 to 2% by mass in all solid components. The aforementioned surfactant can be used alone as one kind, or can be used in combination as two or more kinds.

[0546] The resist composition of the present application can further contain a radical scavenger. By adding a radical scavenger, the light reaction at the time of optical lithography can be controlled and the sensitivity can be adjusted.

[0547] The aforementioned radical scavenger can include a hindered phenol, a quinone, a hindered amine, a mercaptan compound, and the like. Specifically, the hindered phenol can include dibutylhydroxytoluene (BHT), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and the like. The quinone can include 4-methoxyphenol (metoquinone), hydroquinone, and the like. The hindered amine can include 2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-N-oxyl, and the like. The mercaptan can include dodecanethiol, hexadecanethiol, and the like.

[0548] The resist composition of the present application contains the aforementioned radical scavenger, and the content thereof is preferably 0.01 to 10% by mass in the total solid content. The aforementioned radical scavenger can be used singly or in combination of two or more.

[0549] The resist composition of the present application can further contain a crosslinking agent. By adding the crosslinking agent, the crosslinking reaction during the photolithography can be promoted, the glass transfer point of the pattern can be improved, and a fine line resolution excellent pattern can be obtained.

[0550] The aforementioned crosslinking agent can include a compound having a carbon-carbon unsaturated bond such as a vinyl group, a (meth)acrylate group, an allyl group, an alkynyl group, an aromatic ring, or the like as a functional group. Specifically, the compound having a vinyl group can include a chain olefin, a branched olefin, a cyclic olefin, and the like, which can have a substituent. The compound having a (meth)acrylate group can include an acrylic acid, a methacrylic acid, an acrylate, a methacrylate, and the like, which can have a substituent. The compound having an allyl group can include an allyl alcohol, an allyl ether, an allyl ester, an allyl amide, an allyl amine, an allyl-containing isocyanurate, and the like, which can have a substituent. The compound having an alkynyl group can include a chain alkyne, a branched alkyne, a cyclic alkyne, an alkynyl alcohol, an alkynyl ether, an alkynyl ester, an alkynyl amide, an alkynyl amine, an alkynyl-containing isocyanurate, and the like, which can have a substituent. The compound having an aromatic ring can include an aromatic hydrocarbon, a heteroaromatic hydrocarbon, a styrene, a stilbene, a phenylacetylene, an acenaphthene, a Chalcone, and the like, which can have a substituent. The crosslinking agent can have only one of the aforementioned functional groups or a plurality of the functional groups. The number of the aforementioned functional groups contained in the crosslinking agent is preferably 1 or more and 10 or less, and more preferably 2 or more and 8 or less.

[0551] The resist composition of the present application contains the aforementioned crosslinking agent, and the content thereof is preferably 0.01 to 50% by mass in the total solid content. The aforementioned crosslinking agent can be used singly or in combination of two or more.

[0552] The resist composition of the present application contains the aforementioned crosslinking agent, and can further contain a photopolymerization initiator. The photopolymerization initiator generates a radical by irradiation of high-energy rays and promotes the crosslinking of the aforementioned crosslinking agent.

[0553] Specific examples of the aforementioned photopolymerization initiator can include: benzophenone, O-benzoyl methyl benzoate, 4-benzoyl-4'-methylbenzophenone, dibenzyl ketone, fluorenone and other benzophenone derivatives; 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)-benzyl]-phenyl}-2-methylpropane-1-one, methyl phenylglyoxylate and other acetophenone derivatives; thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, diethylthioxanthone and other thioxanthone derivatives; benzoin, benzoin dimethyl ketal, benzoin-β-methoxyethyl acetal and other benzoin derivatives; benzoin methyl ether, 2-hydroxy-2-methyl-1-phenylpropane-1-one and other benzoin derivatives; 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1,3-diphenylpropanetone-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetone-2-(O-benzoyl)oxime-1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)]ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) and other oxime-based compounds; 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)-benzyl]phenyl}-2-methylpropane and other α-hydroxy ketone-based compounds; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butanone and other α-aminoalkyl phenyl ketone-based compounds; bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide and other phosphine oxide-based compounds; bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium and other titanocene compounds and the like.

[0554] The content of the aforementioned photopolymerization initiator in the resist composition of the present application is preferably 0.1 to 10% by mass, more preferably 0.1 to 5% by mass, and most preferably 0.1 to 1% by mass, in the total solid content. If it is 0.1% by mass or more, the blending effect can be sufficiently obtained.

[0555] The aforementioned resist composition of the present application contains a hypervalent iodine compound, a carboxyl group-containing compound, and a photoacid generator as main components, but does not contain a polymer containing an acid-labile group as in a known chemically amplified resist composition. However, the resist composition of the present application can form a positive pattern in which the exposed portion is soluble in a developer, particularly using EB or EUV exposure. The mechanism thereof has not been fully elucidated, but is presumed as follows.

[0556] The hypervalent iodine compound represented by formula (1), (2), (3), or (4) is a tricoordinated compound having an aryl group and a carboxylate ligand. It is considered that such a tricoordinated iodine compound, by being mixed with a carboxyl group-containing compound, undergoes exchange of the carboxylate ligand in an equilibrium reaction. At this time, if the original carboxylate ligand is removed by any means, a hypervalent iodine compound having a new ligand is generated. For example, if 1-iodonaphthylene diacetate as a hypervalent iodine compound is mixed with a carboxyl group-containing compound, and the generated low-boiling acetic acid is removed, the ligand exchange is completed. Here, the carboxyl group-containing compound becomes a crosslinked polymer by the hypervalent iodine compound.

[0557] The polymer crosslinked with the hypervalent iodine compound is generated at the time of film formation. The reason is that even if such a crosslinked polymer is synthesized in advance, it is not soluble in almost all organic solvents, and thus a solution cannot be prepared. It is presumed that this is because the hypervalent iodine compound, which originally has low solvent solubility due to large polarity, further deteriorates the solubility by using a carboxyl group-containing compound as a ligand. Therefore, it is desirable to provide a step of removing the original low-molecular carboxylic acid component at the time of film formation and in a baking step thereafter, thereby completing the ligand exchange reaction, and simultaneously forming a resist film.

[0558] In the resist film obtained from the resist composition of the present application, the hypervalent iodine compound as a main component thereof is decomposed by light, whereby the polarity changes, and a pattern is formed using a developing step. The mechanism thereof has not been fully elucidated, but is presumed as follows, for example.

[0559] The resist film obtained from the resist composition of the present application contains a polymer crosslinked by a hypervalent iodine compound at the time of film formation. However, it is decomposed by light, and thereby converted into a monovalent iodine compound, and the crosslinking of the carboxyl group-containing compound with the hypervalent iodine compound is also released, and the molecular weight is also reduced. As a result, a positive pattern in which the exposed portion is removed by an organic solvent is formed.

[0560] The resist composition of the present application, in addition to containing the high-valent iodine compound and the carboxyl group-containing compound, further contains a photoacid generator, whereby a positive pattern can be formed with high sensitivity compared to a resist composition to which no photoacid generator is added. The mechanism thereof has not been elucidated completely, but is presumed as follows.

[0561] In the resist composition of the present application, by adding the photoacid generator, the acid generated from the photoacid generator at the exposure step of the resist causes exchange with the ligand of the high-valent iodine compound, and becomes a new ligand, whereby the bonding of the carboxyl group-containing compound to the high-valent iodine compound is released. Therefore, in addition to the cleavage of the I-O bond by light, a polarity change or a decrease in molecular weight (when the carboxyl group-containing compound is a polymer) due to exchange of the new ligand by the acid generated from the photoacid generator occurs, and it is presumed that a positive pattern can be formed with high sensitivity by development with an organic solvent.

[0562] From the foregoing presumption, the resist composition of the present application is a non-chemically amplified resist composition containing a photoacid generator, and a polymer containing an acid-labile group as in known chemically amplified resist compositions is not necessary. Therefore, the acid generated from the photoacid generator at the exposed portion reacts with the ligand of the high-valent iodine compound, and becomes a new ligand of high-valent iodine. That is, since there is no amplification mechanism of generating acid again by reacting with the acid-labile group as in chemically amplified resist compositions, adverse effects due to acid diffusion (such as blurring) do not occur, and a fine pattern can be resolved.

[0563] The resist composition of the present application is particularly effective in EUV lithography. This is due to the fact that the iodine atom has a high absorption ability for EUV light. That is, shot noise can be reduced, and higher resolution and lower LWR can be achieved.

[0564] As for an EUV resist composition in which a fine pattern can be formed, there has been a report of a metal resist (for example, Patent Literature 2) in which a metal tin compound having a high absorption ability for EUV light as well as the iodine atom is used as a main component. However, as described above, such a metal resist has many problems such as insufficient solubility in a solvent, storage stability, and defects due to post-etching residue caused by the presence of a metal element. On the other hand, the resist composition of the present application is advantageous in terms of defects compared to the metal resist since no metal element is used, and there is no problem in terms of solubility in a solvent. Furthermore, the resist composition of the present application can be applied to a positive type. For example, a metal resist developed in a negative type in a contact hole forming step requires a reverse processing step after a column pattern is formed, whereas a positive resist does not require such a step. Therefore, the resist composition of the present application can also be said to be more useful than the metal resist in terms of process simplicity.

[0565] Patent Documents 1 and 2 describe a resist composition containing a high-valent iodine compound as an additive or a resist composition in which a high-valent iodine compound is incorporated into the polymer skeleton of a base polymer. However, as for the characteristics of the resist compositions described in these patent documents, only a chemically amplified resist composition in which an acid-labile group in a polymer unit is essential is described, and the line edge roughness can be improved, but there is no mention at all of the possibility that the high-valent iodine compound can be photodecomposed or the possibility that the high-valent iodine compound can function as a material for a non-chemically amplified resist composition. Furthermore, according to the description and examples related to the blending amount, the high-valent iodine compound is not a main component. Therefore, it is considered that the materials described in these patent documents cannot be conceived as the material of the present application, which can reduce shot noise in EUV lithography and, as a material for a non-chemically amplified resist composition, can form a fine pattern. That is, it can be said that the present application is to provide a novel resist composition and a pattern forming method.

[0566] [Pattern forming method]

[0567] When the resist composition of the present application is used in the manufacture of various integrated circuits, a known photolithography technique can be used. For example, as for the pattern forming method, a method including the following steps can be exemplified:

[0568] forming a resist film on a substrate or on a lower layer film of a substrate having the lower layer film,

[0569] exposing the aforementioned resist film to high-energy rays, and

[0570] developing the aforementioned exposed resist film as necessary using a developing solution.

[0571] First, the resist composition of the present application is applied to a substrate for integrated circuit manufacture or to a lower layer film of a substrate (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, an organic antireflection film, etc.) having the lower layer film or to a substrate for mask circuit manufacture or to a lower layer film of a substrate (Cr, CrO, CrON, MoSi2, SiO2, etc.) having the lower layer film, using an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating, so that the coating film thickness becomes 0.01 to 2 μm. This is prebaked on a hot plate, preferably at 60 to 200°C for 10 seconds to 30 minutes and more preferably at 80 to 180°C for 30 seconds to 20 minutes, to form a resist film. In addition, the lower layer film means a film formed between a substrate and a resist film in a multilayer resist process. The aforementioned lower layer film is not particularly limited and a known one can be used.

[0572] Then, the aforementioned resist film is exposed to high energy rays. The aforementioned high energy rays can include ultraviolet rays, far ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer laser, gamma rays, synchrotron radiation, and the like. When the aforementioned high energy rays are ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser, gamma rays, synchrotron radiation, and the like, the exposure is performed directly or using a mask for forming a pattern of interest, with an exposure dose of preferably about 1 to 300 mJ / cm 2 and more preferably about 10 to 200 mJ / cm 2 . When the high energy rays are EB, the exposure is performed directly or using a mask for forming a pattern of interest, with an exposure dose of preferably about 0.1 to 8000 μC / cm 2 and more preferably about 0.5 to 5000 μC / cm 2 . In addition, the resist composition of the present application is particularly suitable for fine patterning by EB or EUV among high energy rays.

[0573] After the exposure, PEB is performed as necessary. At this time, it is preferable to perform the PEB on a hot plate or in an oven at a temperature of 30 to 200°C for 10 seconds to 30 minutes and more preferably at a temperature of 60 to 120°C for 30 seconds to 20 minutes.

[0574] After the exposure or after the PEB, development is performed as necessary using a developer to implement the patterning. The developer used at this time can include: an aqueous alkali solution such as a tetramethylammonium hydroxide aqueous solution, a tetrabutylammonium hydroxide aqueous solution; an organic solvent such as 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, 5-methyl-2-hexanone, methylcyclohexanone, acetophenone, methyl acetophenone, isopropyl alcohol, isoamyl alcohol, n-butyl alcohol, t-butyl alcohol, t-amyl alcohol, n-amyl alcohol, cyclohexanol, formic acid, acetic acid, propionic acid, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, cyclohexyl acetate, 4-t-butylcyclohexyl acetate, octyl acetate, isocamphyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl pentanoate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenylacetate, benzyl formate, phenethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, 2-propanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methyl-1-butanol, diacetone alcohol, 4-methyl-2-pentanol, 3-methylcyclohexanol, 3,5,5-trimethylhexanol, 2,6-dimethyl-4-heptanol, toluene, anisole, ε-caprolactone, and the like. These developers can be used singly or in a mixture of two or more.

[0575] After the development, if necessary, a rinse is performed. The rinse liquid is preferably a solvent that is miscible with the developer and does not dissolve the resist film. Such a solvent can desirably be used: an alcohol having a carbon number of 3 to 10, an ether compound having a carbon number of 8 to 12, an alkane, alkene, alkyne, aromatic solvent having a carbon number of 6 to 12.

[0576] By performing the rinse, the collapse of the resist pattern and the occurrence of defects can be reduced. Also, the rinse is not essential, and by not performing the rinse, the amount of solvent used can be reduced.

[0577] [Examples]

[0578] Hereinafter, the present application is specifically described by way of synthesis examples, examples, and comparative examples, but the present application is not limited to the following examples.

[0579] [1] Synthesis of Polymer

[0580] The monomers used for the synthesis of the polymers P-1 to P-5 are described below.

[0581] [Chemical Formula 192]

[0582]

[0583] [Chemical 193]

[0584]

[0585] [Chemical 194]

[0586]

[0587] [Synthesis Example 1] Synthesis of Polymer P-1

[0588] A monomer-polymerization initiator solution was prepared by measuring monomer b-1 (56 g), monomer c-1 (36 g), V-601 (Fuji Photo Film Co., Ltd. and Chempure Co., Ltd.) 5.4 g, and MEK (180 g) in a flask under a nitrogen atmosphere. In another flask adjusted to a nitrogen atmosphere, MEK (55 g) was measured and heated to 80°C while stirring, and then the above monomer-polymerization initiator solution was added dropwise over 4 hours. After the dropwise addition was completed, the temperature of the polymerization solution was maintained at 80°C and stirring was continued for 2 hours, and then it was cooled to room temperature. The resulting polymerization solution was added dropwise to hexane 4000 g stirred vigorously, and the precipitated polymer was separated by filtration. The resulting polymer was washed twice with hexane (1200 g), and then vacuum dried at 50°C for 20 hours to obtain polymer P-1 as a white powder (yield 90 g, yield 98%). The Mw of polymer P-1 was 8000, and Mw / Mn was 1.42. In addition, the Mw was a polystyrene conversion value determined using THF as a solvent by GPC.

[0589] [Chemical 195]

[0590]

[0591] [Synthesis Examples 2 to 5] Synthesis of Polymers P-2 to P-5

[0592] Polymers shown in Table 1 below were synthesized in the same manner as in Synthesis Example 1, except that the types and blending ratios of the respective monomers were changed.

[0593] [Table 1]

[0594]

[0595] [2] Preparation of Resist Composition

[0596] [Examples 1-1 to 1-18, Comparative Examples 1-1 to 1-3]

[0597] A high-valent iodine compound, a carboxyl group-containing compound, and a photoacid generator were dissolved in a solvent containing 0.01 mass% of a surfactant (PF-636, manufactured by OMNOVA) in the compositions shown in Table 2 below, and the obtained solution was filtered with a Teflon (registered trademark) filter of 0.2 μm, whereby resist compositions (R-01 to R-18 and CR-01) were produced. Also, a polymer, a photoacid generator, and a sensitivity adjustor were dissolved in a solvent containing 0.01 mass% of a surfactant (PF-636, manufactured by OMNOVA) in the compositions shown in Table 3 below, and the obtained solution was filtered with a Teflon (registered trademark) filter of 0.2 μm, whereby resist compositions (CR-02 and CR-03) were produced.

[0598] [Table 2]

[0599]

[0600]

[0601] [Table 3]

[0602]

[0603] In Tables 2 and 3, the high-valent iodine compounds I-1 to I-3, the carboxyl group-containing compounds m-1 to m-3, the photoacid generators PAG-1 to PAG-7, the sensitivity adjustors Q-1, and the solvents are as described below.

[0604] [Chemical Formula 196]

[0605]

[0606] [Chemical Formula 197]

[0607]

[0608] [Chemical Formula 198]

[0609]

[0610] [Chemical Formula 199]

[0611]

[0612] • Solvent: AcOH (acetic acid)

[0613] GBL (γ-butyrolactone)

[0614] [3] Evaluation of EUV lithography (line and space pattern) [Examples 2-1 to 2-18, Comparative Examples 2-1 to 2-3]

[0615] Each of the resist compositions (R-01 to R-18, CR-01 to CR-03) was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content: 43 mass%) manufactured by Showa Denko K.K. was formed in a film thickness of 20 nm, and prebaking (PAB) was performed for 60 seconds at the temperature described in Table 4 using a hot plate to produce a resist film having a film thickness of 40 nm. After exposure of a 36 nm line and space (LS) pattern at 1 : 1 using an EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination) manufactured by ASML Co., PEB was performed for 60 seconds at the temperature described in Table 4 on a hot plate, and then development was performed for 30 seconds using the developer described in Table 4 to form an LS pattern having a space width of 18 nm and a pitch of 36 nm.

[0616] The following evaluations were performed on the obtained resist pattern. The results are shown in Table 4.

[0617] [Sensitivity Evaluation]

[0618] The aforementioned LS pattern was observed using a length measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and the optimum exposure amount Eop (mJ / cm2) at which an LS pattern having a space width of 18 nm and a pitch of 36 nm could be obtained was determined and made the sensitivity. 2

[0619] [LWR Evaluation]

[0620] The dimensions of 10 places of the LS pattern obtained by irradiation at the optimum exposure amount were measured in the length direction of the space width using a length measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and the value 3 times the standard deviation (σ) obtained from the results thereof (3σ) was made the LWR. The smaller this value, the more uniform the space width pattern having a small roughness could be obtained.

[0621] [Limit of Resolution Evaluation]

[0622] The limit line width (nm) at which resolution was performed when a pattern was formed by gradually increasing the exposure amount in small amounts from the optimum exposure amount at which the aforementioned LS pattern was formed was determined using a length measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and this was made the limit of resolution (nm). The smaller this value, the better the limit of resolution, and the more fine the pattern that could be formed.

[0623] [Table 4]

[0624]

[0625]

[0626] Developer: nBA (butyl acetate)

[0627] ​TMAH (2.38 mass% tetramethylammonium hydroxide aqueous solution)

[0628] As is apparent from the results shown in Table 4, when comparing Example 2-1 and Comparative Example 2-1, a pattern can be formed with high sensitivity by adding a photoacid generator. Also, when comparing Comparative Examples 2-1 to 2-3, it is apparent that the more the photoacid generator is added, the more a pattern can be formed with high sensitivity. As is apparent from Example 2-4, by adding two photoacid generators having different acidities, the diffusion of the strong acid to the unexposed portion can be quenched by the photoacid generator generating a weak acid, and thus a pattern with high resolution can be obtained. Also, as is apparent from Examples 2-9 and 2-10, when using a photoacid generator having a large molecular weight, a pattern with high resolution can be obtained because the diffusion length of the acid is short. It is apparent that even when compared with Comparative Examples 2-2 and 2-3, which are chemical amplification resist compositions using an acid catalyst reaction, the resist composition of the present application is excellent in sensitivity, resolution, and LWR. Thus, it is apparent that the resist composition of the present application can form a resist pattern with excellent sensitivity in LS pattern formation by EUV exposure.

[0629] [4] Evaluation of EUV lithography (contact hole pattern)

[0630] [Examples 3-1 to 3-18, Comparative Examples 3-1 to 3-3]

[0631] Each of the resist compositions (R-01 to R-18, CR-01 to CR-03) was spin-coated on a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (content of silicon: 43 mass%) manufactured by Showa Denko K.K. was formed to have a film thickness of 20 nm, and a PAB was performed for 60 seconds at the temperature described in Table 5 using a hot plate to produce a resist film having a film thickness of 50 nm. Then, the aforementioned resist film was exposed using an EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, a mask of a hole pattern having a size of 64 nm pitch on a wafer, +20% offset) manufactured by ASML, and a PEB was performed for 60 seconds at the temperature described in Table 5 on a hot plate, and development was performed for 30 seconds using the developing solution described in Table 5 to obtain a hole pattern having a size of 32 nm.

[0632] Evaluation was performed on the obtained resist pattern as follows. The results are shown in Table 5.

[0633] [Resolution evaluation]

[0634] The aforementioned contact hole pattern was observed using a length measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation to find the optimum exposure amount Eop (mJ / cm2) at which a hole pattern having a size of 22 nm could be obtained, and this was made the resolution. 2

[0635] ​[CDU evaluation]

[0636] The size of 50 hole patterns 50 obtained by irradiation at the optimum exposure amount was measured, and the value 3 times the standard deviation (σ) obtained from the results was taken as the CDU. The smaller this value, the more uniform the hole diameter pattern can be obtained.

[0637] [Limit resolution evaluation]

[0638] The limit hole diameter (nm) of the resolution performed when forming hole patterns by gradually reducing the exposure amount from the optimum exposure amount for forming the hole pattern described above was measured using a length-measuring SEM (CG-6300) manufactured by Hitachi High-Technologies Corporation, and was taken as the limit resolution (nm). The smaller this value, the better the limit resolution, and the more fine the hole diameter pattern that can be formed.

[0639] [Table 5]

[0640]

[0641] As can be seen from the results shown in Table 5, when comparing Example 3-1 and Comparative Example 3-1, it can be seen that by adding a photoacid generator, a pattern can be formed with high sensitivity. Also, when comparing Comparative Examples 3-1 to 3-3, it can be seen that the more photoacid generator added, the more a pattern can be formed with high sensitivity. From Example 3-4, it can be seen that by adding two photoacid generators with different acid strengths, the diffusion of strong acid to the unexposed portion can be quenched by the photoacid generator that generates weak acid, and thereby a pattern with high resolution can be obtained. Also, from Examples 3-9 and 3-10, it can be seen that when using a photoacid generator with a large molecular weight, because the diffusion length of the acid is short, a pattern with high resolution can be obtained. It can be seen that even when compared with Comparative Examples 3-2 and 3-3, which are chemical amplification resist compositions using an acid catalyst reaction, the resist composition of the present application is excellent in sensitivity, resolution, and CDU. Therefore, it can be seen that the resist composition of the present application can form a resist pattern with excellent sensitivity in the formation of contact hole patterns performed by EUV exposure.

Claims

1. A resist composition comprising: The high-valent iodine compound is at least one of any of the following formulas (1) to (4). Onium salt compounds containing a sulfonium cation represented by formula (5-1) or a sulfonium cation represented by formula (5-2), and an anion represented by a halide ion, nitrate ion, bisulfate ion, bicarbonate ion, tetraphenylborate ion, or any of the following formulas (5-3) to (5-9). Compounds containing carboxyl groups, and Solvent; In the formula, m1 is 0, 1, or 2; when m1 is 0, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, or 5, and 1 ≤ n1 + n2 ≤ 6; when m1 is 1, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7, and 1 ≤ n1 + n2 ≤ 8; when m1 is 2, n1 is 1, 2, or 3, n2 is 0, 1, 2, 3, 4, 5, 6, or 7. n1, n2, n3, n4, n5, n6, n7, n8, n9, n1, n2, n4, n5, n6, n7, n8, n9, n9, n1, n2, n3, n4, n4, n5, n6, n7, n8, n9 ... When m2 is 0, 1, or 2; when m2 is 0, n9 is 0, 1, 2, 3, or 4; when m2 is 1, n9 is 0, 1, 2, 3, 4, 5, or 6. R 1 ~R 8 Each is an independent hydrocarbon group consisting of halogen atoms or may contain heteroatoms, having 1 to 10 carbon atoms; also, R 1 and R 2 R 3 and R 4 R 5 and R 6 、or R 7 and R 8 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms; R 11 ~R 14 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms; when n2 is 2 or more, each R 11 They can be the same or different, and there are multiple Rs. 11 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n4 is 2 or more, each R 12 They can be the same or different, and there are multiple Rs. 12 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n6 is 2 or more, each R 13 They can be the same or different, and there are multiple Rs. 13 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n7 is 2 or more, each R 14 They can be the same or different, and there are multiple Rs. 14 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; R 15 R is a (n8) valence hydrocarbon group with 1 to 40 carbon atoms or a (n8) valence heterocyclic group with 2 to 40 carbon atoms. When n8 is 2, R 15 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, sulfonyl group, or thionyl bond; furthermore, part or all of the hydrogen atoms of the (n8) valence hydrocarbon group or (n8) valence heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the (n8) valence hydrocarbon group can also be replaced by a group containing a heteroatom, and R 14 and R 15 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms; R 21 It is a hydrocarbon group with 1 to 10 carbon atoms, which may contain halogen atoms or heteroatoms; R 22 It is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms; when n9 is 2 or more, each R 22 They can be the same or different; also, multiple Rs 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; R 23 It is a carbonyl group or may contain a hydrocarbon group with 1 to 10 carbon atoms; *1 and *2 represent the atomic bonds of the carbon atoms in the aromatic ring in the formula; however, *1 and *2 are bonded to adjacent carbon atoms in the aromatic ring. In the formula, R 31 ~R 35 Each is an independent hydrocarbon group consisting of halogen atoms or may contain heteroatoms, having 1 to 30 carbon atoms; also, R 31 and R 32 They can also bond to each other and form rings together with the sulfur atoms they are bonded to; In the formula, k1 and k2 are 1, 2, 3 or 4 independently, respectively; Rf 1 and Rf 2 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms, but all Rf 1 and Rf 2 It cannot simultaneously be a hydrogen atom; R 41 It can be a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group with 1 to 50 carbon atoms that may contain heteroatoms; R 42 It is a hydrocarbon group with 1 to 50 carbon atoms, consisting of hydrogen atoms, halogen atoms, hydroxyl groups, or heteroatoms; but excluding those in which the hydrogen atoms at the α and β positions of the sulfonate group are replaced by fluorine atoms or fluoroalkyl groups. R 51 It can be a hydrogen atom, a halogen atom, a hydroxyl group, or a hydrocarbon group with 1 to 50 carbon atoms that may contain heteroatoms; R 52 It is a hydrocarbon group with 1 to 50 carbon atoms, consisting of hydrogen atoms, halogen atoms, hydroxyl groups, or heteroatoms; but excluding those in which the hydrogen atoms at the α and β positions of the carboxyl group are replaced by fluorine atoms or fluoroalkyl groups. R 61 and R 62 Each can be an independent hydrocarbon group with 1 to 50 carbon atoms, which may also contain heteroatoms; R 71 ~R 73 Each can be an independent hydrocarbon group with 1 to 50 carbon atoms, which may also contain heteroatoms; R 81 It is a fluorinated hydrocarbon group consisting of a fluorine atom or 1 to 10 carbon atoms, and this fluorinated hydrocarbon group may also contain a hydroxyl group, an ether bond, or an ester bond; R 82 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and this hydrocarbon group may also contain a hydroxyl group, an ether bond, or an ester bond; also, R 81 With R 82 They can also bond to each other and form rings together with the atoms they are bonded to.

2. The resist composition according to claim 1, wherein, The carboxyl-containing compound is a polymer containing a repeating unit represented by formula (6) or a compound represented by formula (7); In the formula, R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group; X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -;X A1 It is a saturated alkylene group, phenylene group, or naphthylene group with 1 to 10 carbon atoms, and the saturated alkylene group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring; * indicates an atomic bond with a carbon atom in the main chain; p is 1, 2, 3 or 4; R 91 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 91 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group or sulfonyl group; furthermore, part or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing heteroatoms, and part of the -CH2- of the p-valent hydrocarbon group can also be replaced by a group containing heteroatoms. R 92 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group can be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group can also be replaced by a group containing a heteroatom; when p is 2, 3 or 4, each R 92 They can be the same or different.

3. The resist composition according to claim 2, wherein, Polymers containing repeating units represented by formula (6) do not contain acid-labile groups.

4. A layered body, comprising: substrate, and A resist film on the substrate obtained from the resist composition according to any one of claims 1 to 3.

5. The laminate according to claim 4, wherein a photoresist underlayer is provided between the substrate and the photoresist film.

6. The laminate according to claim 4, wherein, The resist film is formed by ligand exchange between the high-valent iodine compound and a carboxyl-containing compound.

7. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate or on the lower layer film of a substrate having a lower layer film laminated using the resist composition according to any one of claims 1 to 3. The resist film was exposed using i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet light. The exposed resist film was developed using a developer.

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